The rationale behind secondary prevention post-ST-elevation myocardial infarction (STEMI) is well established. Guidelines recommend titration of several medications for secondary prevention up to a maximally tolerated dose in order to confer maximum benefit. Due to decreasing duration of inpatient stays post-myocardial infarction (MI), this up-titration must often take place in primary care. Guidelines also recommend clearly informing GPs regarding duration of dual antiplatelet therapy and monitoring cardiovascular risk factors. Clear communication between secondary/tertiary and primary healthcare practitioners is essential in order to ensure our patients are receiving optimum care.
We examined all discharge summaries for patients discharged post-STEMI in our tertiary referral centre. This encompassed rates of prescribing of the National Institute for Health and Care Excellence (NICE) recommended medications post-MI, rates of therapeutic prescribing of these medications and communication with GPs regarding duration of dual antiplatelet therapy, up-titration of medications and repeat checking of fasting lipid profiles. In order to improve compliance with guidelines, incoming junior staff were educated on guidelines for communication post-STEMI at our journal club. We then re-audited our practice in order to see if compliance with the guidelines improved.
Our results showed that, while the majority of our patients were discharged on the correct medications post-MI, most were receiving subtherapeutic doses of angiotensin-converting enzyme (ACE) inhibitors and beta blockers. In addition, we exhibited poor communication with primary healthcare practitioners. Compliance with the NICE guidelines on communication significantly improved after our intervention.
In conclusion, education of junior staff can significantly improve communication with GPs. This, in turn, could help optimise secondary prevention strategies post-MI.
Introduction
Coronary artery disease remains one of the leading causes of death in Ireland,1 the UK,2 and worldwide. Despite advances in management, it is a major source of morbidity and mortality in our healthcare system. Numerous trials (PROVE-IT,3 ISIS-1,4 ISIS-2,5 ISIS-3,6 ISIS-4,7 AIRE,8 CAPRICORN9) have established the prognostic benefits associated with adequate secondary prevention post ST-elevation myocardial infarction (STEMI).
National Institute for Health and Care Excellence (NICE) guidelines10 recommend all patients discharged post-STEMI should be offered treatment with an angiotensin-converting enzyme inhibitor (ACEi), beta blocker (BB), dual antiplatelet therapy (DAPT) and a statin. The evidence for these medications is based on trials in which the drugs were used at high doses. The benefit at lower doses is not clear and best practice dictates titrating medications up to the maximally tolerated dose. This has been shown to reduce morbidity and mortality for these patients, reducing recurrent hospital admissions, re-infarction and death.3–9
The guidelines10 also state that patients should be discharged with clear information for their general practitioner (GP) regarding incomplete dose titrations and plans for antiplatelet and anticoagulant treatment.
Clear instructions are essential, as GPs may be reluctant to make changes to medications prescribed by specialists. Given many medications cannot be up-titrated to maximally tolerated doses during brief inpatient stays,11 the GP plays a key role in ensuring this is done as an outpatient.
If the medication is not titrated up to the maximally tolerated dose, the patient may not derive maximum benefit and may suffer an increased risk of major adverse cardiac events (MACEs).
We hope that a focus on improved communication will lead to improved clinical outcomes, patient experience and continuity of care between primary and secondary or tertiary care services.
Materials and methods
In this study, we aimed to assess the compliance with guidelines on communication with GPs. Subsequently, we sought to improve this through education of our junior staff.
Using our STEMI database and the computerised discharge prescriptions on our electronic patient record (EPR) system, we analysed the prescribing rates of BB, DAPT, ACEi and statins for all patients presenting as STEMI calls in 2015. We also analysed the percentage of patients discharged on therapeutic doses of these medications. The presence or absence of clear instructions for GPs regarding up-titration of medication doses, duration of DAPT and repeating fasting lipid profiles was also noted.
For study purposes, the subtherapeutic doses of NICE recommended drugs for use post-MI were defined as those used in a previous audit on medication dosage post-STEMI:10
- ACEi: lisinopril <10 mg per day, perindopril <4 mg per day, ramipril <5 mg per day
- BB: atenolol <50 mg per day, bisoprolol <5 mg per day, carvedilol <25 mg per day, metoprolol <50 mg per day
- Statins: atorvastatin <80 mg per day, rosuvastatin <10 mg per day, simvastatin <40 mg per day
- Antiplatelets: aspirin <75 mg per day, clopidogrel <75 mg per day, ticagrelor <180 mg per day.
These were selected arbitrarily based on similar studies on therapeutic prescribing in the UK. Patients with no dose specified on the discharge prescription were classified as non-therapeutic.
It was felt that lack of education was a significant factor in our disappointing initial results. In order to tackle this, a short talk was delivered to the new junior doctors assigned to our service at the beginning of their cardiology rotation. This comprised of a brief overview of the NICE guidelines on communication with GPs post-STEMI, in addition to the results from our initial audit of practice over the previous year. A random sample of 34 consecutive STEMI discharges was then audited from the following three months (all STEMIs between 14 May 2016 to 14 June 2016) using similar methodology.
Rates of compliance were compared using the Z-test for two population proportions using a two-tailed test at a significance level of p<0.05.
Results
Our results are summarised in tables 1 and 2.
Our initial study highlighted that there was significant room for improvement in communication with GPs. Only 19.87% of our discharge summaries informed the GP to up-titrate BB and ACEi to the maximally tolerated dose, however, therapeutic prescribing rates for these medications were only 17.4% and 14.14%, respectively. While some patients may have had contraindications to higher doses of these medications (bradycardia, hypotension, renal disease), it was felt to be unlikely that this was the case in over 80% of our patients.
Just over half of our discharge summaries informed the GP of the duration of antiplatelet therapy and only 36.8% informed them to repeat fasting lipids. This was despite only two-thirds of our patients being prescribed a therapeutic dose of a statin.
After our intervention, we achieved a statistically significant improvement in rates of communication with GPs with regard to duration of antiplatelet therapy and up-titration of medications. There was no statistically significant difference in communication regarding repeat testing of fasting lipid profiles (p=0.1936).
Discussion
Numerous trials have demonstrated the benefit of secondary prevention post-STEMI.3–9 This consists of medical treatment with DAPT, a statin and a BB. In patients with evidence of left ventricular dysfunction, ACEi have also been shown to confer a prognostic benefit.12 Adequate secondary prevention reduces major adverse cardiac events.10.
With improvements in management, inpatient stays for patients with acute infarcts have shortened considerably.13 This may make it difficult to up-titrate medication regimens to therapeutic dosages while under the care of the specialist team. In addition, some medications require monitoring of haemodynamic parameters like heart rate and blood pressure, or biochemical parameters like electrolytes and renal function, before deciding on dose up-titration. As such, the GP plays a crucial role in performing this as an outpatient. In order to facilitate this, it is essential that specialist care providers explicitly detail the need for up-titration of medications with instructions for the same.
The need to optimise outcomes post-MI is well described. Coronary artery disease is the leading cause of death in Ireland1 and amounts to a significant cost burden on the healthcare system. A study from the UK estimated the financial burden of suboptimal care post-MI to be in the region of £9 billion.14
Discharge summaries are a crucial component of the patient care pathway. They represent the continuation of care between specialist services and primary healthcare practitioners. They are an opportunity to communicate future plans for ongoing patient management and to provide guidance on long-term care with regard to medication regimens. However, these are usually completed by junior staff, who may be unaware of the guidelines regarding communication with primary care. They may also be uncomfortable explicitly dictating plans for up-titration of medications unless they themselves are explicitly informed of the same by their senior colleagues.
Our junior doctors rotate at three-monthly intervals through our service. Such frequent turnover presents a further challenge. In order to tackle this, an educational session was delivered to the incoming doctors regarding the results of our previous study and NICE guidelines on communication with GPs post-STEMI. As seen in table 2, this resulted in statistically significant improvements in rates of compliance with guidelines on communication with regard to medication up-titration and duration of DAPT.
This highlights the importance of continuous education of junior staff with regard to guidelines for communication. Improving this communication may, in turn, improve our patients’ long-term outcomes, by ensuring they are on the optimum secondary prevention regimen post-STEMI.
Conflict of interest
None declared.
Editors’ note
See also the editorial by Dr Terry McCormack (page 127) in this issue.
Key messages
- Myocardial infarction is a significant cause of mortality and morbidity in modern healthcare
- Adequate secondary prevention reduces major adverse cardiac events post-discharge
- This requires communication with general practitioners regarding up-titration of medication regimens and plans for future treatment
- Communication between secondary/tertiary services and primary healthcare providers can be substandard, potentially compromising patient care
- Education of junior staff, who are often responsible for composing discharge summaries, is essential to ensure compliance with guidelines.
References
1. Central Statistics Office. Statistical yearbook of Ireland 2015. Cork: CSO, 2015. Available from: http://www.cso.ie/en/releasesandpublications/ep/p-syi/statisticalyearbookofireland2015/people/vitalstatistics/
2. British Heart Foundation. Statistics Database. 1. Mortality. Available from: http://www.heartstats.org/temp/2008.Chaptersp1.pdf
3. Cannon C, Braunwald E, McCabe C et al. Intensive versus moderate lipid lowering with statins after acute coronary syndromes (PROVE IT-TIMI 22). N Engl J Med 2004;350:1495–504. http://dx.doi.org/10.1056/NEJMoa040583
4. First International Study of Infarct Survival Collaborative Group. Randomised trial of intravenous atenolol among 16 027 cases of suspected acute myocardial infarction: isis-1. Lancet 1986;328:57–66. http://dx.doi.org/10.1016/S0140-6736(86)91607-7
5. ISIS-2 (Second International Study of lnfarct Survival) Collaborative Group. Randomised trial of intravenous streptokinase, oral aspirin, both, or neither among 17 187 cases of suspected acute myocardial infarction: ISIS-2. Lancet 1988;332:349–60. http://dx.doi.org/10.1016/S0140-6736(88)92833-4
6. ISIS-3 (Third International Study of lnfarct Survival) Collaborative Group. ISIS-3: a randomised comparison of streptokinase vs tissue plasminogen activator vs anistreplase and of aspirin plus heparin vs aspirin alone among 41 299 cases of suspected acute myocardial infarction. Lancet 1992;339:753–70. http://dx.doi.org/10.1016/0140-6736(92)91893-D
7. ISIS-4 (Fourth International Study of lnfarct Survival) Collaborative Group. ISIS-4: a randomised factorial trial assessing early oral captopril, oral mononitrate, and intravenous magnesium sulphate in 58 050 patients with suspected acute myocardial infarction. Lancet 1995;345:669–82. http://dx.doi.org/10.1016/S0140-6736(95)90865-X
8. The AIRE Study Investigators. Effect of ramipril on mortality and morbidity of survivors of acute myocardial infarction with clinical evidence of heart failure. The acute infarction ramipril efficacy (AIRE) study investigators. Lancet 1993;342:821–8. http://dx.doi.org/10.1016/0140-6736(93)92693-N
9. McMurray JJ, Dargie HJ, Ford I et al. Carvedilol reduces supraventricular and ventricular arrhythmias after myocardial infarction: evidence from the CAPRICORN study. Presented at American Heart Association Scientific Sessions in Anaheim, CA; November 11–14, 2001: abstract 3303.
10. National Institute for Health and Care Excellence. Myocardial infarction: secondary prevention overview. Available at: http://pathways.nice.org.uk/pathways/myocardial-infarction-secondary-prevention
11. Stewart KJ, Woothipoom P, Townsend JN. Achieving the dose: an audit of discharge medication for the secondary prevention of myocardial infarction. Br J Cardiol 2010;17:142–3. Available from: https://bjcardio.co.uk/2010/05/achieving-the-dose-an-audit-of-discharge-medication-for-the-secondary-prevention-of-myocardial-infarction/
12. Cleland JGF, Puri S. How do ACE inhibitors reduce mortality in patients with left ventricular dysfunction with and without heart failure: remodelling, resetting, or sudden death? Br Heart J 1994;72(3 suppl):S81–S86. http://dx.doi.org/10.1136/hrt.72.3_Suppl.S81
13. Saczynski JS, Lessard D, Spencer FA et al. Declining length of stay for patients hospitalized with AMI: impact on mortality and readmissions. Am J Med 2010;123:1007–15. http://dx.doi.org/10.1016/j.amjmed.2010.05.018
