Monthly Archives: March 2010

Routine cardioversion for patients with atrial fibrillation

Br J Cardiol 2010;17:55-6 Leave a comment
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In this issue, Sandler’s paper (see pages 86–8) reinforces the growing body of evidence that should lead to the demise of the routine use of direct current cardioversion (DCCV) for patients with atrial fibrillation. This interesting paper highlights several issues surrounding DCCV within the context of a service re-design within a district general hospital. Despite a state-of-the-art service, the success of DCCV was limited, with sinus rhythm maintained in between the stated 20% (22/110) or even optimistically 40% (22/55) at around one year. I would suggest that this is unacceptable and that we would not allow any other procedure with significant associated morbidity to be undertaken with such a low chance of succeeding.

Istock7It may be that these figures are actually very good compared with data from other centres, given that this service was designed specifically to reduce the delay in receiving DCCV. It would be interesting, therefore, to have more data on the types of patients receiving cardioversion, and whether there are any factors that may predict both initial and long-term success. It is clear, for example, from other data that the current National Institute for Health and Clinical Excellence (NICE) recommendations to utilise cardioversion for patients with heart failure need revising.1

Patient selection

If we look at the results in some detail it is clear that the whole issue of patient selection and management prior to the procedure remains to be elucidated. In common with other centres, a high number of procedures were cancelled due to low International Normalised Ratio (INR) measurement. The current recommendation is for the INR to be maintained between 2.5 and 3.0 for six weeks prior to cardioversion. This is very difficult to achieve. Problems arise when the INR, having been stabilised using one monitoring system, is measured using a different monitoring system on admission. Surely the issue is not what the absolute INR value is, which can vary by 0.5 INR units even between reliable systems,2 but rather whether there is clot in the left atrium. If we are to reduce the overall numbers of patients undergoing cardioversion would it not be safer, and more effective, to undertake high-resolution scanning to detect clot, rather than relying on indirect markers such as INR?

Sandler provides no data on outcomes other than sinus rhythm, thus we do not know if any direct harm was attributable to the procedure itself. Even without these data, however, only around half of patients were in sinus rhythm six weeks after the procedure. Thus, even in a state-of-the-art facility designed to minimise delay in receiving the procedure, only half of patients had a successful outcome at six weeks, with possibly only 20% at one year. No mention is made here of management of oral anticoagulation in these patients, and whether the patients lost to follow-up had significant morbidity or not. Given that other studies have demonstrated worse outcomes in terms of morbidity, such as hospital admissions and pulmonary symptoms, attributable to anti-arrhythmic drugs, this may be the cause of loss to follow-up.3

Is it acceptable?

The time has come, therefore, for those of us who manage patients with atrial fibrillation to question whether routine cardioversion is acceptable. Sandler outlines the current NICE criteria for consideration of restoration of sinus rhythm as “symptomatic, younger patients, those presenting for the first time with lone AF, those with AF secondary to a treated/corrected precipitant and those with congestive heart failure”. We have already seen that heart failure is not an indication for cardioversion, and it may be that, with time, the other indications drop off also.

I would argue that cardioversion should currently only be considered for patients with acute onset of atrial fibrillation, probably within 24 hours, or for patients who remain symptomatic despite optimal medical therapy. I would re-iterate that even in these scenarios, successful cardioversion cannot automatically lead to discontinuation of oral anticoagulation therapy. As it stands, I would recommend continuing oral anticoagulation therapy for at least one year following successful cardioversion. If sinus rhythm is maintained at one year, it may be worth a trial without anticoagulants, however, regular review would be absolutely essential.

Conflict of interest

None declaired.

Editors’ note

Please see the article ‘Whatever happens to the cardioverted’ by David A Sandler on pages 86–8 of this issue.

References

  1. Roy D, Talajic M, Nattel S et al. Rhythm control versus rate control for atrial fibrillation and heart failure. N Engl J Med 2008;358:2667–77.
  2. Fitzmaurice DA, Gardiner C, Kitchen S, Mackie I, Murray ET, Machin SJ. An evidence-based review and guidelines for patient self-testing and management of oral anticoagulation. Br J Haematol 2005;131:156–65.
  3. The AFFIRM investigators. Relationships between sinus rhythm, treatment and survival in the atrial fibrillation follow-up investigation of rhythm management (AFFIRM) study. Circulation 2004;109:1509–13.

New NICE guidance on VTE prevention

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The National Institute for Health and Clinical Excellence (NICE) has issued new guidance on the prevention of venous thromboembolism (VTE) in patients admitted to hospital.

NICE calculates that an estimated 25,000 people who are admitted to hospital die from preventable VTE each year.  The NICE guideline, jointly developed with the National Clinical Guideline Centre for Acute and Chronic Conditions, recommends that all patients should be assessed for risk of developing blood clots on admission to hospital, and then given preventative treatment that suits their individual needs. Options include anticoagulant drugs such as heparin, anti-embolism stockings and foot impulse or pneumatic devices.  This advice covers all patients admitted to hospital – including those having day-case procedures – and not just those patients having surgery.

The guideline gives recommendations on how to assess if patients are at risk of developing VTE, and their risk of bleeding before anticoagulant drug treatments are used. This includes considering if patients are likely to have reduced mobility for three or more days, the type of procedure they are being admitted for, the age of patients and any pre-existing conditions.  Specific recommendations are given for women who are pregnant or have given birth within the previous six weeks.

The guidance includes mention of the new oral anticoagulants – rivaroxaban and dabigatran – which have recently been approved for use in hip- and knee-replacement surgery patients. It says: “There are important changes expected in anticoagulation if the oral agents recently licensed or currently undergoing evaluation prove to be safe and consistently effective”. It adds: “If during the lifetime of this guideline they fulfill the hope that many doctors have for them, they will simplify practice that at present relies on daily injections of an anticoagulant”.

Commenting on the new guidance, Dr Fergus Macbeth, Clinical Director at NICE, said: “There is a real clinical need for this guideline. It has been reported that measures to prevent VTE in hospital patients are used inconsistently, and in many cases patients at significant risk of developing a blood clot don’t get any preventative treatment at all.”

Professor Ian Gilmore, President of the Royal College of Physicians, added: “Patients may not always have symptoms to give a warning – but occasionally VTE can cause pain and swelling in the leg.  The importance of assessing patients on admission, not a day or so afterwards, is raised, along with the need to re-assess patients within 24 hours of admission and whenever the clinical situation changes”.

The NICE guideline, “Reducing the risk of venous thromboembolism in patients admitted to hospital”, is available at www.nice.org.uk/CG92 .

NICE preliminary hearing negative on new antiarrhythmic 

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The National Institute for Health and Clinical Excellence (NICE) has issued a draft guidance on the new anti-arrhythmic drug, dronedarone, saying it does not recommend its use to treat atrial fibrillation (AF), because “it is less effective and costs considerably more than existing treatments”. It is estimated that dronedarone costs around £2.25 per day compared with about £0.05 for amiodarone.

Istock6But UK cardiologists and arrhythmia patient/professional groups, led by the Atrial Fibrillation Association and Heart Rhythm UK, have been petitioning to have this draft recommendation overturned. A second NICE meeting on dronedarone was held at the end of February to consider all the comments that have been received, and a final guidance is expected in the next few weeks.

As part of the campaign to allow dronedarone to be available for NHS prescription, more than 100 doctors have signed an open letter to NICE setting out reasons why the drug is needed. A Parliamentary Stakeholder Investigation on the issue has been held and a Parliament Early Day Motion has also been drawn up and signed by several MPs.

The motion sets forth that “dronedarone is a first-in-class antiarrhythmic drug and the only antiarrhythmic medication known to improve long-term cardiac health in AF patients” and that “many people with AF who currently struggle to manage the condition would benefit from access to this treatment, and its use would yield considerable cost savings in the longer term through reduced hospital admissions and reduced incidence of stroke”.

What is the best blood sugar level in diabetics? –New UK data

Br J Cardiol 2010;17:59-61
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A new UK study has suggested that both very low and very high blood sugar levels in type 2 diabetes are associated with increased all-cause mortality and cardiac events.

These findings are in line with those of the US ACCORD trial which was stopped early because of an increased risk of death in type 2 diabetes patients who underwent intensive blood glucose lowering compared with conventional therapy.

In the new UK study, published recently in The Lancet (Lancet 2010;375:481–9), the lowest death and event rates were seen at an HbA1c level of 7.5%.

The new data come from studying around 48,000 type 2 diabetes patients aged 50 or over who are included in the UK General Practice Research Database. These patients had either had their treatment intensified from oral monotherapy to combination therapy with oral blood glucose lowering agents, or had changed to regimens that included insulin.

Results showed that compared with the HbA1c decile with the lowest hazard (median HbA1c 7.5%), the adjusted hazard ratio for all-cause mortality in the lowest HbA1c decile (median 6.4%) was 1.52 and in the highest HbA1c decile (median 10.5%) was 1.79.

The 10% of patients with lowest HbA1c values (<6.7%) had a higher death rate than all but those in the top 10%, who had an HbA1c of 9.9% or higher. Cardiovascular disease was also more frequent in this low-HbA1c group than in any other decile.

Mortality was three times higher in patients who had severe hypoglycemia than in those who did not have severe hypoglycemia, suggesting that the increase in mortality in the low sugar decile could have been related to hypoglycemia, the researchers suggest.

In addition, mortality was higher in patients treated with insulin versus those given combination oral agents. “These data imply for oral combination therapy that a wide HbA1c range is safe with respect to all-cause mortality and large-vessel events, but for insulin-based therapy, a more narrow range might be desirable,” the authors write.

An accompanying editorial, says that individualisation of therapy is key, requiring differing recommendations according to the patient. It adds that intensive treatment seems to be more beneficial for cardiovascular outcomes for those who are younger than 60 years, with a short duration of diabetes and absence of microvascular and macrovascular disease.

Hormone replacement therapy and heart disease risk in younger women 

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Among recently menopausal women, hormone replacement therapy (HRT) with both oestrogen and progestin, showed a slight non-significant increase in risk of coronary heart disease within the first few years of use in a new analysis of the Women’s Health Initiative (WHI).

The increase in risk of around 29% during the first two years of use, disappeared after six years of use, and with longer use there appeared to be a possible cardioprotective effect of HRT.OK

The researchers say the results should not affect current recommendations for women to take HRT, if required, to relieve menopausal symptoms, but to use it at the lowest dose and for the shortest time possible. The analysis is published in the February 16th issue of the Annals of Internal Medicine (Ann Intern Med 2010;152:211–17).

The results of this new WHI analysis appear to be in conflict with a recent statement from the International Menopause Society and the European Society of Cardiology, which says there is a trend that HRT is cardioprotective in younger women. (Climacteric 2009;12:368–77).

Cardiovascular services in London – the case for change

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A document outlining how London’s acute and complex cardiovascular services are currently provided and broad principles for how things could be improved, Cardiovascular services in London: the case for change, has now been published.

LAS1This document has been produced by Commissioning Support for London, an organisation established by the capital’s 31 primary care trusts (PCTs), in response to Lord Darzi’s 2007 report which found that while there is excellence in healthcare in London, this excellence is not provided equally across the capital.

The cardiovascular project has been split into three areas of work each with key objectives:

  • Vascular services – specialist and emergency vascular services
  • Cardiac surgery – all cardiac surgery, except paediatrics and transplants
  • Cardiology – emergency and complex interventional cardiology procedures.

The project is clinically-led and each area of work has a nominated clinical lead supported by a clinical expert panel, and has also been advised by a patient panel.

The Case for change document says the initiative addresses longer than necessary waiting times for surgery, lengths of stays in hospital, and quality of care.

Specific issues mentioned that need to be addressed include:

Abdominal aortic aneurysm repair: new figures showing that UK patients have significantly worse mortality rates following abdominal aortic aneurysm repair than other leading European countries. They are also less likely to be treated using new technology and have the longest hospital stays.

Delays for non-elective cardiac surgery: the best healthcare systems in the world have a total pathway for non-elective cardiac surgery (from decision to operation to leaving hospital after surgery) of around two weeks. In London this can take up to almost three times as long (52 days). This delay puts patients at risk from suffering a venous thrombo-embolism, having a cardiac event or acquiring a hospital infection. To begin improving the situation in London, a total pathway length of no more than three weeks is recommended.

Reducing the length of stay: there is a dramatic variation in the length of stay in hospital following cardiac and vascular surgery, depending on which hospital undertakes the surgery. Standardised processes are needed to ensure patients return home when they are clinically ready. If every unit matched the best length of stay, there would be huge benefits for patients, as well as cost savings and efficiency gains.

Aortic dissection: although the number of patients suffering life-threatening aortic dissection in London every year is small, they suffer high mortality rates with many people never even reaching a hospital. To save more lives, patients need prompt treatment by a specialist surgeon and the London cardiac community needs to come together to provide an out-of-hours emergency service.

Transfer and referral between hospitals: in some parts of London, the total pathway length for patients undergoing non-elective percutaneous coronary intervention (PCI) is more than 10 days. Considering that most patients recover within a couple of days of the procedure, this is far too long.

ICD and CRT devices: compared with the rest of Europe, the UK implants fewer implantable cardioverter deribrillators (ICDs), cardiac resynchronisation therapy (CRT) devices, and pacemakers and performs fewer ablations, leading to considerable unmet demand in the population. More patients need to be identified for these procedures through improved training and networking, and they must be treated in experienced units that demonstrate the highest quality care.

New technology: greater planning for the introduction of new technology with a clearly communicated plan for roll out is needed, initially concentrating expertise in a small number of sites.

Improving academia: the level of research output in London needs to be improved, and the high level of cardiac surgery performed in London, with a wide variety of cases and research laboratories available, offers an ideal opportunity for research.

New roles: training for cardiac surgeons must evolve and there is scope to develop new roles, such as surgical care practitioners.

The Case for change document can be viewed in detail at the Healthcare for London website: www.healthcareforlondon.nhs.uk.

Statins appear to increase risk of diabetes

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A new meta-analysis has suggested that use of statins slightly increases the risk of developing diabetes. The analysis – published in the February 27th issue of The Lancet, (Lancet 2010;375:735-42) – was led by researchers at the University of Glasgow.

They note that trials of statin therapy have had conflicting findings on the risk of development of diabetes. They therefore performed a meta-analysis of published and unpublished data to look at this issue further. They included 13 statin trials with 91,140 participants in total, of whom 4,278 had diabetes during a mean of four years. Treatment of 255 patients with statins for four years resulted in one extra case of diabetes.

They conclude that the risk of developing diabetes with statin therapy is low both in absolute terms and when compared with the reduction in coronary events, and that “Clinical practice in patients with moderate or high cardiovascular risk or existing cardiovascular disease should not change”. The researchers say the mechanism behind this effect remains a mystery.

An accompanying editorial in The Lancet, says the finding is “paradoxical” given the benefit of statins in reducing cardiovascular events in patients with known diabetes. But it adds that “it seems reasonable to add glucose to the list of tests to monitor in older patients who are on statins”.

“Doctor knows best”… Perhaps; but which one?

Br J Cardiol 2010;17:64-6 Leave a comment
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We continue our series in which Consultant Interventionist Dr Michael Norell takes a sideways look at life in the cath lab…and beyond. In this column, he considers the choice between surgery and percutaneous coronary intervention.

So there I was, sitting in one of our twice-weekly multi-disciplinary team (MDT) meetings. I was proffering my sixpence worth on the merits of surgery (coronary artery bypass graft [CABG]) or percutaneous coronary intervention (PCI) (occasionally neither, and – rarely – both), as a succession of clinical data, scans of various types and coronary angiograms were laid before us. And I got to thinking, “is this the way it should be?”

We have come a long way in tailoring treatment to patients. When PCI, or percutaneous transluminal coronary angioplasty (PTCA) as it was then, emerged as a young and promising technique in the late seventies, that decision process was more straightforward. Ballooning (alone) was a reasonable choice in accessible, discrete, concentric and non-calcified single vessel disease, in order to alleviate ischaemic symptoms.

You will note that I avoided the term ‘proximal’, because that hallowed segment of the left anterior descending (LAD) particularly, was then – and perhaps still is now – considered surgical territory in view of its prognostic impact. Nevertheless, in that era, the nature of disease uncovered by angiography was such that the bulk of revascularisation was still surgical and, as a result, discussion regarding other options was largely unnecessary.

New realms

But it was not long before Kansas City’s Geoff Hartzler, and many other pioneers, led us into the realms of multi-vessel PTCA. The randomised trials in the eighties comparing CABG with PTCA were consistently reassuring. They confirmed that the only price paid by embarking upon a less invasive strategy was a higher likelihood of a repeat procedure because of re-stenosis. Things are really no different 20 years later. Predictably, the magnitude of that ‘disadvantage’ became smaller with the introduction of stents, and was to reduce even further with the arrival of their drug-eluting cousins.

The turning point occurred around 10 or so years ago. We were getting better at intervention and were investigating – let alone, treating – many more patients earlier in the course of their disease, their anatomy being far more attractive to the interventionist. Along with more unstable presentations came advancing age and co-morbidity, all three of these factors causing surgeons, still reeling under the public scrutiny of the Bristol enquiry, to pause. And so at this juncture, PCI activity in the UK began to overhaul that of CABG, and – to be honest – we have not looked back since.

Harder choices

Recent ‘real-world’ studies have shown that similar outcomes can be achieved with either PCI or CABG in selected patient subsets, and so there is now an increasing need for debate about a specific individual’s treatment in even more cases. Traditionally, these ‘discussions’ have consisted of brief corridor chats or a few grabbed minutes with a CD in one hand and a tuna sandwich in the other. But perhaps the structure of that process now deserves to be better defined.

How should such a meeting be constructed and which of the multi disciplines should attend? Presumably, at least a surgeon and an interventionist would be a minimum, but what about our anaesthetic colleagues, let alone an individual with none of these skills (which might at least be refreshing)? Should all cases be presented, or just those that demand revascularisation? Or should we limit the forum even further by focusing upon those who need treatment and in whom either surgery or PCI are both deemed to be feasible? But then who, exactly, does the deeming?

Acknowledging that an increasing proportion of most units’ PCI activity is unplanned, there needs to be an acceptance that many cases with multi-vessel disease will still be managed percutaneously (and without discussion) simply because expedience is required on clinical – or sometimes, administrative – grounds.

Influencing outcomes

Once you start down such a formal process, you would be surprised where it leads. There is no doubt that the participants at a MDT meeting can influence its outcome, whether by one speciality outnumbering – and, conceivably, intimidating another (is that actually possible?) – or by the presence or absence of an

individual with specific expertise that might have relevance in certain cases. A ‘pooled’ system may also demand some fine tuning; further intra-speciality discussion might be required to avoid a particularly high-risk case being served up to an operator who might be less than keen to take it on.

Naturally, all relevant clinical data need to be available in order for a decision to be made. The proceedings should be documented (so as to form a record of the discussion), with such a ‘memorandum of understanding’ emphasising particular issues that impacted upon the result. The outcome should be signed off by a Chair, which could rotate between specialities in the hope of avoiding at least the perception of bias (as if…).

Modifications

I have considered two modifications to our own meetings, which I am happy to share with the wider public. First, in order to reassure ourselves that the quality of decision making is robust, I have speculated as to the merits of re-presenting a case to my colleagues (after a suitable delay, of course) to see if we reach the same result; now that would be interesting.

Second: feedback. If a decision rested upon the anticipation of grafting a particular vessel, attending to a valve, re-canalising a chronic occlusion or evaluating a lesion with a pressure-wire, then there should be a mechanism whereby it can be determined that this actually occurred. MDT meetings commonly provoke individuals to ‘talk the talk’, but all parties must be reassured that, when push came to shove, they also ‘walked the walk’.

More often than not, in cases that could be revascularised to an equivalent extent with either modality, the consensus often rests upon just how much ‘work’ PCI would involve. Re-opening a lengthy chronic occlusion of the right, bifurcation stenting in the circumflex and dealing with long and diffuse LAD disease, might all require a total of five or six stents. Depending on the surgical risk, that numeric level might be considered a threshold at which CABG starts to become ‘acceptable’, so to speak. Such an approach (the Anticipated Stent Summation score) might be seen as a surrogate for procedural difficulty, analogous to the system utilised in the recent SYNTAX trial (I don’t recommend using the acronym, however).

Patient opinion

There is of course another contributor to the MDT process, as yet not mentioned, namely the patient. When all else fails, putting the information in front of the person to be treated and inviting him or her to choose their management, does seem somewhat intuitive. However, human nature being what it is, the patient might well accept a less invasive and low-risk procedure now, even if it means the possibility of further ‘attention’ at a later date. That seems entirely reasonable.

When I was training, many of the patients with acute coronary syndromes whom we now stent routinely, would never have got to the cath lab in the first place. Thus, I for one am not going to lose too much sleep if a patient with severe multi-vessel disease is managed surgically, even if I know I could do the same job at lower risk – all be it with a high ASS score (sorry about that).

At the end of the day it’s all about openness and transparency. If a choice of treatment is made on a patient’s behalf then the route to that decision should at least be made clear.

Cardiorenal syndrome: one disease – two paths?

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A report from the fourth Annual Scientific Meeting of the Cardiorenal Forum.

cardiorenalIntroduction

That renal and cardiac disease appear inseparable from an epidemiological perspective is unsurprising, since they share many risk factors, notably hypertension, diabetes and inflammation. To date, however, our focus on the disparate specialities of ‘cardiology’ and ‘nephrology’ has reinforced a perception of each system as separate. The Cardiorenal Forum (CRF) was established to challenge this perspective.

The most recent meeting, last autumn, ‘Optimising care at the cardiorenal interface’ was organised by the Royal College of Physicians, the British Cardiovascular Society and the Renal Association, in association with the CRF. The meeting sought, first to reconsider the relationship between renal function and cardiovascular outcome, and to explore the current state of management of kidney disease with a particular focus upon haemodialysis. Sessions also examined the association between renal dysfunction, heart failure and diuretic resistance, and the need for integration across healthcare boundaries to address these increasingly prevalent conditions.

Epidemiology and eGFR

The prevalence of end-stage renal disease is rising, due increasingly to reno-vascular disease and type 2 diabetes; perhaps reflecting ageing populations and better management of elevated blood pressure. As renal function deteriorates, the rate of cardiovascular events rises.1

To improve awareness of renal disease in the general population requires a reliable assessment of renal function. Serum creatinine, although widely available, is unreliable. Creatinine rises only in established renal disease, thus relatively normal levels may provide false reassurance. This can be partially ‘corrected’ by using the reciprocal of serum creatinine. More recently, estimation of glomerular filtration rate (eGFR), using either the Cockcroft-Gault or Modification of Diet in Renal Disease (MDRD) formulae has been shown to more closely reflect directly measured creatinine clearance.2 Both methods suffer practical confounding through differential correction for age and female sex, the inclusion of weight in the Cockcroft-Gault formula and of age in MDRD. In addition, eGFR rises in the first decade of nephropathy reflecting hyperfiltration. The detection of microalbuminuria during this early phase of hyperfiltration may more accurately define early renal impairment. Thus, while eGFR may be above the typical watershed of 60 ml/min, the presence of microalbuminuria defines stages I and II of chronic kidney disease (CKD).

Once eGFR falls below 60 ml/min, cardiovascular risk accelerates, although the strength of this association is markedly reduced when corrected for a full range of cardiovascular risk factors.3 It is, thus, unclear whether renal impairment is intrinsically a risk factor in cardiovascular disease or merely reflects a collated risk factor burden. It remains the case, however, that the lower the eGFR the greater the likelihood of adverse outcome in patients following myocardial infarction4 and in patients with heart failure.5

The mainstay of treatment in patients with renal impairment is inhibition of the renin–angiotensin system (RAS). While there is strong evidence for benefit across a range of cardiovascular disease, recent studies suggest a threshold for effect, with loss of benefit,6 and possibly harm,7 at lesser degrees of renal impairment (eGFR >60 ml/min). In the presence of microalbuminuria, RAS inhibition may reduce the rate of progression of proteinuria, however, the evidence-base is more disparate. It is uncertain if delaying progression of proteinuria delays progressive renal impairment; again a threshold effect may also exist at lesser levels of microalbuminuria.8

The inclusion of the measurement of eGFR within the Quality Outcomes Framework (QOF) has increased awareness and reporting of renal disease within primary care, with some evidence of increased early referral to specialist care. Attention has simultaneously been drawn to the limitations of eGFR. To obviate at least part of the problem with the age dependence of estimation of eGFR by MDRD, CKD stage III has recently been sub-divided into III (a) and III (b) at an eGFR of 45 ml/min.

Service organisation

An increased awareness of renal impairment coupled with the mantra that CKD is “one piece of a vascular jigsaw” that includes diabetes, hypertension and cardiovascular disease is a heady combination. Awareness of the problem does not, however, equate with effective treatment, which requires much better integration of services than “our focus on structures and not on the patient” allows. In outlining the “primary care home” where “if fulfilled, our policies are taking us”, David Colin-Thome provided an ambitious vision of integration (not only of primary and secondary care but of social services), which may well be a necessary realisation of the financial straits that we approach. At present, however, such idealism seems to sit uncomfortably alongside the fragmentation of primary care into isolated commissioning and provider ventures, of commissioning into primary care trusts (PCTs) and consortia, and of community services into units run by various external agencies.

When the dust settles, perhaps truly integrated local services will exist (no longer a primary/secondary divide?) with clinically driven disease management programmes capable of dealing with the growing burden of chronic disease, such as heart failure. For, in an ageing population, it is in heart failure that the entanglement of chronic kidney and vascular disease reaches its apogee.

Heart failure

The association between heart failure and renal impairment is well recognised with over 30% of patients in the Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity (CHARM) study population having an eGFR of <60 ml/min. In those with an eGFR of <30 ml/min the primary outcome of cardiovascular death or heart failure hospitalisation was three times more common.5 This association was present irrespective of the ejection fraction. While it is relatively straightforward to envisage decreased renal perfusion as a consequence of reduced cardiac output in patients with systolic left ventricular dysfunction, this does not, however, explain the association between renal impairment and failure in those with preserved ejection fraction. This latter population is expanding, and frequently presents to hospital with oedema, which, in my experience, becomes increasingly intransigent as renal function deteriorates.

Although refractory oedema is well recognised in patients with established heart failure, therapeutic options remain markedly limited. Provided there is good adherence to treatment and no conflicting therapeutic (non-steroidal anti-inflammatories or calcium channel blockers) or physiological (anaemia or hypothyroidism) explanation, then diuretics remain the mainstay of treatment. Based principally upon clinical observation, diuretic infusion is probably more effective than bolus doses. With due diligence, ‘sequential nephron blockade’ (the targeting of multiple sites of action with the combination of loop and thiazide diuretics as well as spironolactone) may also help diuresis in refractory cases. Sadly, recent clinical studies of intravenous dopamine, natriuretic peptide infusion or of oral adenosine or vasopressin antagonists have all been unsuccessful. For refractory oedema there remains ultrafiltration,9 which may best have a role in younger patients (<70 years) who lack evidence of substantial renal dysfunction. Care needs to be taken not to ‘over-diurese’ the patient. The possibility of peritoneal dialysis is being explored.

Dialysis

Once established, decline in renal function is inexorable. No effective intervention has yet been found to halt this progression with both the correction of renal artery stenosis and high-dose statin recently disappointing. When end-stage renal disease is reached, only dialysis or transplantation remain. Dialysis, which is increasingly performed, has been shown to place an immense haemodynamic insult upon the cardiovascular system, accounted for predominantly by the maximum drop in blood pressure and the volume of filtrate removed during the procedure.10 In addition, dialysis produces substantial, cumulative myocardial stunning and dysfunction, and induces a strong, systemic inflammatory response. Interestingly, it has been suggested that frequent low-grade troponin release might even encourage the development of auto-antibodies to troponin and an ‘auto-immune carditis’. The possibility of ‘gentler’ dialysis is being explored, with the goal of reduced blood pressure changes and filtrate volume through frequent, possibly domestic, nocturnal dialysis. Although sudden death occurs in 7% of this population, the underlying reasons are unclear. Whether there might be a specific role for implantable defibrillators is not known.

Conclusion

Our understanding of the relationship between chronic renal and cardiovascular disease is, as yet, elemental, and based more on observation and empirical enquiry than on scientific study.

Whilst helpful in raising awareness of renal impairment, eGFR remains confounded by age and body mass. Therapies to prevent progression of renal disease are lacking. Although the mainstay of treatment in the later stages of renal disease, it seems likely that dialysis is itself a strong cardiovascular risk factor. We are left with one single clinical intervention – early detection and treatment of elevated blood pressure.

There is obviously a great need for further research, which is now being addressed by the recently established Cardio-Renal Trial Group. Perhaps the greatest paradox is that patients with renal impairment have been excluded from cardiovascular studies for so long. This needs to be challenged. In closing the meeting, Professor Roger Boyle (National Director of Heart Disease and Stroke) commented on the “huge interaction” between cardiovascular and renal disease, and wondered “why we have gone down different paths for so long”

Hugh McIntyre
Consultant Cardiovascular Physician

East Sussex Hospitals Trust
([email protected])

For more information on the Cardiorenal Forum and future events, see www.cardiorenalforum.com

References

  1. Go AS, Chertow GM, Fan D, McCulloch CE, Hsu CY. Chronic kidney disease and the risks of death, cardiovascular events, and hospitalization. N Engl J Med 2004;351:1296–305.
  2. Verhave JC, Gansevoort RT, Hillege HL, De Zeeuw D, Curhan GC, De Jong PE. Drawbacks of the use of indirect estimates of renal function to evaluate the effect of risk factors on renal function. J Am Soc Nephrol 2004;15:1316–22.
  3. Manjunath G, Tighiouart H, Ibrahim H et al. Level of kidney function as a risk factor for atherosclerotic cardiovascular outcomes in the community. J Am Coll Cardiol 2003;41:47–55.
  4. Anavekar NS, McMurray JJ, Velazquez EJ et al. Relation between renal dysfunction and cardiovascular outcomes after myocardial
    infarction. N Engl J Med 2004;351:1285–95.
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The British Society for Heart Failure 12th Annual Autumn Meeting

Br J Cardiol 2010;17:69-70 Leave a comment
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Highlights of this year’s British Society for Heart Failure (BSH) meeting, held in November in London, included a call for specialist heart failure units which could see more patients receiving optimum treatment, how to treat ‘difficult’ cases and how devices are showing benefit in those patients with less severe disease.

BSH

Optimising care

UK hospitals should set up acute heart failure units to help raise standards of care, according to Professor Henry Dargie (Golden Jubilee National Hospital, Glasgow).

Presenting the inaugural Philip Poole-Wilson memorial lecture (see box), Professor Dargie said that there have been great improvements in heart failure treatment, with effective drugs, devices and interventions, plus a multidisciplinary team approach. In addition, clinical trials have shown a 50% absolute reduction in heart failure mortality with modern treatments, proving what can be achieved with specialist care.

But trial results are not being reproduced in clinical practice and mortality from heart failure remains high.

Better organisation of care is needed and heart failure care should “move towards myocardial infarction (MI) status”, Professor Dargie suggested, emphasising that coronary care units underlie the improved treatment of MI. The reorganisation of stroke care within specialist stroke units has also been a success. “The case for heart failure units is overwhelming,” he said. “Acute heart failure will be more easily identified and treated in a specialist setting. It is not enough to say that a patient has heart failure. We have to know what is causing it. This is not a simple issue which is why specialist care is very important.”

A heart failure unit could take patients from hospital clinics, acute admission units, primary care, and also MI patients with acute heart failure in coronary care units.

Within a specialist unit it would be easier to make sure that patients receive optimum treatment. Advanced therapies, such as devices, are currently used much less than the National Institute for Health and Clinical Excellence (NICE) recommends and this is partly because patients who could benefit are not being identified.

Professor Dargie commented that the reduction in heart failure mortality which could be obtained by better use of the available therapies was likely to be much greater that the reduction in MI mortality from the move to primary percutaneous coronary intervention. He called for a feasibility study of heart failure units.

He also emphasised the need for a UK trial of ventricular assist devices (VADs) for destination therapy. Professor Poole-Wilson had been one of many people trying to set up such a trial. “We should redouble our efforts as evidence is crucial,” he said.

Audit results disappointing

Dr Theresa McDonagh (Royal Brompton Hospital, London) reported the latest data from the National Heart Failure Audit. She pointed out that while heart failure prognosis has been steadily improving in areas where there is good specialist care, the national data are more disappointing.

The data cover patients admitted to hospital in England and Wales with a diagnosis of heart failure. They show 30% one-year mortality. This is strongly related to age: mortality is 6% in patients aged under 45 years, increasing to 48% in patients over 85 years. One-year mortality is higher in patients admitted to a general medical ward than in those treated on a cardiology ward.

The audit shows in-hospital mortality of 10.5%, which is higher than in recent European and US surveys. Access to investigations in secondary care is better than in a 2005 Healthcare Commission survey and there is also improved discharge prescribing of evidence-based therapy.

Dr McDonagh encouraged participation in the audit to ensure that reliable data are obtained. To date, 71% of acute trusts have registered for the audit and 60% of those have submitted data.

In primary care, Dr Ahmet Fuat (Carmel Medical Practice, Darlington) said that several aspects of heart failure care have improved but there is still under-prescribing of beta blockers (the recent addition of beta blocker prescribing as a Quality and Outcomes Framework clinical indicator might help here) and a need for more uptitration of ACE inhibitor/angiotensin receptor blocker therapy. Better collaboration across primary, secondary and tertiary care is also required: “Integrated care is the way forward,” he said.

Encouraging better use of CRT and ICD

Simon Williams (Wythenshawe Hospital, Manchester) reviewed advanced heart failure care and highlighted the low use of cardiac resynchronisation therapy (CRT) and implantable cardioverter-defibrillators (ICD) relative to other Western European countries.  To some extent CRT use was being held back by the NICE requirement for echocardiographic measures of dyssynchrony. But he said that several centres no longer select CRT patients on this basis. At his hospital, any patient with a QRS duration >120ms on ECG is generally put forward for CRT.

CRT is at present recommended for selected patients with New York Heart Association class III or IV heart failure although Dr Rakesh Sharma (Royal Brompton Hospital, London) reported that there is increasing evidence of benefit in patients with less severe heart failure. MADIT-CRT and the REVERSE extension study both showed CRT benefit in patients with asymptomatic or mildly symptomatic heart failure. MADIT-CRT compared CRT with a defibrillator (CRT-D) and ICD: survival free of heart failure (the primary end point) was significantly better in the CRT-D group.

Dr Sharma said that with ICDs the challenge is to identify patients who are likely to benefit. “This is important because only around 10% of primary prevention patients receive life-saving therapy from their ICD and there can be problems with the therapy,” he said.

Use of natriuretic peptide (NP) testing as a “rule out” test in heart failure diagnosis has been an important development and the Conference heard that the recent Health Technology Assessment’s endorsement of the role of NP testing in primary care should improve availability of the test.

Dr Theresa McDonagh commented that NPs are the only validated biomarkers for use in diagnosis of heart failure. At present, they are also the best prognostic markers but many other biomarkers are being investigated that, in future, might well be used in combination with NPs for better risk stratification. She said that promising new biomarkers include cystatin C (a serine protease inhibitor) and ST2 (a member of the interleukin -1 receptor family).

Sleep apnoea

The conference heard from Dr Anita Simonds (National Heart and Lung Institute, London) that a high proportion of patients with heart failure have some form of sleep-disordered breathing. This is often central sleep apnoea for which optimum treatment is not yet clear – a European study is currently investigating a new strategy of adaptive servo-ventilation for these patients.

Heart failure patients with moderate to severe obstructive sleep apnoea benefit from nasal continuous positive airway pressure (CPAP) therapy, with improvement in cardiac function and in quality of life. “CPAP is undoubtedly the treatment of choice for these patients and should be available to them,” Dr Simonds said, adding that cardiologists should have a low threshold for referral for sleep studies.

Difficult heart failure

In a session on “difficult heart failure”, Professor Martin Cowie (National Heart and Lung Institute, London) discussed diuretic resistance. He said this is a common problem, particularly as heart failure advances, with limited randomised controlled trial evidence on treatment. Potential causes include poor adherence to diuretic therapy, excess dietary sodium, drug interactions (especially with NSAIDs) and chronic kidney disease. Chronic loop diuretic therapy can itself make the kidney more resistant to diuretics, while resistant fluid retention can also be a marker of deteriorating heart failure.

Treatment of resistant fluid retention can involve increased dose or frequency of loop diuretic, and IV rather than oral dosing (with continuous infusion better than bolus injection). Sequential nephron blockade with addition of thiazides to loop diuretics can also be effective but it is important to monitor blood pressure and creatinine. Professor Cowie commented that ultrafiltration is likely to become more routine in clinical practice although there are still practical challenges to this.

Professor Andrew Clark (University of Hull) suggested that ultrafiltration might also be useful for increasing serum sodium in patients with hyponatraemia. He said that hyponatraemia is a late event in the course of chronic heart failure and tends to be seen in patients in whom control of fluid balance is becoming difficult. Traditional treatments are often ineffective and unpleasant for the patient. The new vasopressin antagonists (‘vaptans’) are a promising treatment.

The BSH website (www.bsh.org.uk) contains information on future conferences or contact the Secretariat on tel: 01865 391836; email: [email protected]

Inaugural memorial lecture honours BSH founding president Philip Poole-Wilson

Professor Henry Dargie receives a medal from Mrs Mary Poole-Wilson after presenting the Philip Poole-Wilson memorial lecture
Professor Henry Dargie receives a medal from Mrs Mary Poole-Wilson after presenting the Philip Poole-Wilson memorial lecture

Professor Philip Poole-Wilson, who died in March 2009, was founding president of the BSH. In his honour, the Society has introduced a Philip Poole-Wilson memorial lecture. The inaugural lecture was given at the Autumn Meeting by Professor Henry Dargie.

Introducing the lecture, Professor Martin Cowie, said that Professor Poole-Wilson’s sudden death was a great loss to cardiology. He said: “Philip was the Simon Marks British Heart Foundation Professor of Cardiology at the National Heart and Lung Institute, Imperial College, for 20 years. What was remarkable was not only his own research but the way that he fostered new ideas and new people. He was very generous with his time and intellectual capacity. He was also President of the European Society of Cardiology, helping to make it a more cogent body, and President of the World Heart Federation where he worked to raise the importance of cardiovascular disease among policymakers in both the developed and the developing world.”

A fund has been set up in memory of Professor Poole-Wilson to raise money for the British Heart Foundation. Donations can be made at: http://www.mygiftofhope.org.uk/BHFWebSiteCS/Hope/ViewFund.aspx?PageId=662