Clinical articles

Cardiovascular magnetic resonance (CMR) imaging is a rapidly developing subspecialty with a clear training structure and good career prospects. Demand for CMR demand is growing rapidly, with an 85% increase in cases scanned nationally in only two years, and this demand is predicted to continue with the British Cardiovascular Society working group predicting a further trebling of demand in the five years from 2010 to 2015. The most recent British Junior Cardiology Association survey identified cardiovascular imaging as an increasing preference for subspecialty training with 22% of trainees choosing imaging in 2012 (up from 10% in 2005) and CMR as the preferred imaging modality (selected by 45%). However, it was highlighted that there were still difficulties in accessing training by around one third of trainees. We describe the common indications for CMR, what CMR training involves (including the accreditation process), as well as how trainees can access current training opportunities.

New high-sensitivity troponin assays will reduce the threshold for the diagnosis of myocardial infarction (MI), as specified in the 2012 third Universal Definition of MI. They will also allow earlier diagnosis of MI, but serial testing is required for adequate specificity. They convey prognostic information in both MI and in other acute conditions. Interpretation of troponin results must be in combination with a full assessment of the clinical context.

This review discusses these concepts and developments in this area.

Monitoring renal function is essential in chronic heart failure (CHF) patients on the combination of aldosterone antagonists (AA) and either angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). The National Institute for Health and Care Excellence (NICE) recommends renal monitoring at weeks 1, 4, 8, 12 and then every three months. We audited the compliance of discharge notes to general practitioners (GPs) by hospital staff with NICE’s safety recommendation. We reviewed the notes of all consecutive CHF patients who were discharged in two periods (1st October to 20th November 2011 and 1st June to 30th June 2012) on the above combination therapy.

In the first audit, of 83 patients discharged on the combination (21 patients were commenced on it in the index admission), 43% met the audit standard. In the re-audit, 51 patients were discharged on the combination (12 had it commenced during the index admission), and 58% met the audit standard (p=not significant). In both audits, no advice at all was made to monitor renal function in 28% of the discharge notes.

Despite a trend of improvement in the rate of adherence to NICE’s safety recommendation between the two audits, almost a third of the patients were discharged without advice to the GP to monitor renal function.

Only a small proportion of patients requiring pacemaker or defibrillator implantation have congenital cardiac abnormalities. Patients with such anomalies can be divided into two categories: those with undiscovered congenital abnormalities, which had not given rise to symptoms or other obvious physical signs, and those known to have congenital abnormalities having had surgical intervention or not.

Pacemaker implantation in these two groups of patients may give rise to practical challenges and the implanting physician should be familiar with them so that potential problems can readily be recognised. In this, and the subsequent articles, we will cover the most common congenital cardiac anomalies with relevance to cardiac device implantation.

Dr John B Pittard, a general practitioner in Staines, comments on whether implementing these research findings is achievable in primary care

Atrial fibrillation (AF) is the most common cardiac dysrrhythmia. The evidence base and expert consensus opinion for management have been summarised in several international guidelines. Recent studies suggest a disparity between contemporary practice and perceived best practice. 

An electronic questionnaire was constructed to capture details of patient demographics and current practice, including risk assessment for stroke and major bleeding. All patients >18 years with AF as a primary or secondary diagnosis admitted from midday on the 14^th September 2011 to midday on the 15^th September 2011, were included in the survey. Participating units were recruited from the Society for Acute Medicine registry, and provided with an electronic link and password to enter data for individual patient episodes.

The electronic questionnaire was completed for 149 patient episodes from 31 acute medical units (AMUs) across the UK. The typical patient with AF presenting to the AMU is older, has important medical comorbidities (sepsis in almost a third) and frequently presents out of hours. Initial management was digoxin alone in 22% and 23% had a documented stroke risk assessment, not in-keeping with current guidelines.

This relatively simple methodology yields valuable insight into the real world management of AF, providing an additional evidence base.

Patients with amyloid heart disease have historically been considered to have a very poor prognosis and were considered almost untreatable. However, recent therapeutic advances are encouraging and likely to have a marked effect on management across the amyloid spectrum. This message needs to be conveyed to cardiologists, not least because there is now benefit to performing an endomyocardial biopsy to determine amyloid type. We provide an update on the significant progress in managing the three most common forms of amyloid heart disease in the UK.

Our objective was to compare the performance of computed tomography coronary angiography (CTCA) with exercise tolerance testing (ETT) in patients presenting with stable chest pain with low-to-intermediate predicted risk of coronary artery disease (CAD) as defined by the UK National Institute for Health and Care Excellence (NICE) clinical guideline 95. We investigated 85 patients with ETT and 102 patients with CTCA as first-line investigations after clinical assessment. Outcome measures assessed were diagnosis or exclusion of CAD, referral for second-line investigations, false-positive rate and cost of investigation to reach diagnosis for each modality.

CTCA was diagnostic in more patients than ETT (95.1% vs. 80.0%, p<0.05), had a lower false-positive rate (2.9% vs. 17.6%), led to fewer referrals for second-line investigations (4.9% vs. 21.2%, p<0.05) and resulted in overall comparable cost of investigation per patient (£183.44 vs. £165.16, p=0.49).

In conclusion, CTCA outperforms ETT as a first-line investigation in the investigation of patients presenting with stable chest pain with low-to-intermediate predicted risk of CAD as defined by NICE clinical guideline 95. 

Incidence of stroke attributable to atrial fibrillation increases from 1.5% at age 50–59 years to 23.5% at age 80–89 years. The use of oral anticoagulants to reduce the risk of stroke is well established, but all the available agents can cause bleeds if used in excess dose, in high-risk patients or in patients with reduced kidney function.

This article highlights the need to assess kidney function as stated in the newly published European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC) practical guide on the use of the new oral anticoagulants (NOACs).¹ The EHRA guide has a section on NOACs for patients with chronic kidney disease (CKD) where it is stated that “a careful follow-up of renal function is required in CKD patients, since all (NOACs) are cleared more or less by the kidney”. It continues “in the context of NOAC treatment, creatinine clearance is best assessed by the Cockcroft method, as this was used in most NOAC trials”.

The authors discuss the issues and present a simple guide on why and how to use the Cockcroft Gault equation for kidney function estimation. They also note that for drug and dosing decisions, reduced kidney function, for whatever reason (not just where a patient has been assessed as having CKD), needs to be assessed to reduce the risk of harm.

Chronic kidney disease (CKD) adversely affects cardiovascular outcomes and mortality in the general population. We sought to determine the impact of renal function on angiographic and clinical results in ST-elevation myocardial infarction (STEMI) patients treated with primary percutaneous coronary intervention (pPCI). 

Analyses were based on the prospective ‘all-comer’ registry of 1,064 consecutive STEMI patients treated with pPCI in our tertiary centre between February 2001 and October 2002. Admission serum creatinine concentration was known in 894 patients (84%). Mean serum creatinine was 105 ± 27 µmol/L and estimated glomerular filtration rate (eGFR) was 67 ± 18 ml/min/1.73 m². Thrombolysis in Myocardial Infarction grade 3 (TIMI3) flow was achieved in 751 patients (84%). During hospitalisation, 29 (3%) major bleedings, five (1%) strokes and 12 (1%) re-infarctions occurred. By day 30, two patients were lost to follow-up and 41 (5%) were dead. Renal function was independently associated with 30-day mortality (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.2–2.1, p=0.003). In CKD patients (eGFR <60 ml/min/1.73 m²), TIMI3 flow was restored less frequently (79% vs. 87%), in-hospital major adverse cardiac and cerebrovascular events (MACCE) were more frequent (15% vs. 4%) and 30-day mortality was higher than in non-CKD patients (9% vs. 2%). Lower eGFR was associated with increased risk of major bleeding (HR 1.6, 95% CI 1.3–2.1, p<0.0005). In the subgroup of conscious patients with normal serum creatinine, eGFR remained significantly associated with 30-day mortality. 

In conclusion, renal function expressed by eGFR is an independent predictor of procedural success and short-term outcomes in STEMI patients treated with pPCI, even in patients with normal serum creatinine. Thus, eGFR should be estimated in all STEMI patients to help identify a high-risk subgroup.