Are Long-Term Beta Blockers Following MI in the Absence of Angina and HF Indicated in the PCI Era?

The use of beta blockers (BB) in acute coronary syndromes (ACS), angina, and heart failure (HF) with reduced ejection fraction (EF) are well-established. However, in the era of reperfusion with percutaneous coronary interventions (PCI), the long-term benefits of BB in coronary artery disease in patients without symptoms of angina or HF are unknown.

1. BB inhibit catecholamine from binding to beta-1 and beta-2 receptors present in the myocardium, thus reducing heart rate, conduction speed, and contractility. Myocardial infarction (MI) causes high sympathetic activity which can be blunted by BB. This leads to reduced oxygen demand, which in turn, protects against cardiac arrhythmias and symptomatic relief from angina.^[1]

2. Immediate myocardial reperfusion following MI is also a strong inhibitor of sympathetic activity. Therefore, the widespread use of long-term BB following MI in completely revascularized patients without residual angina or left ventricle (LV) dysfunction is debated.

3. Most of the data regarding long term benefits of BB stems from studies done in the pre-PCI era and before the widespread use of anti-platelets and statins and therefore extrapolating the results of those trials to current practice presents important limitations.^[2]

4. The use of BB in patients with non-ST-elevation MI (STEMI) with preserved EF is a class IIa recommendation by the 2014 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines; however, European Society of Cardiology (ESC) guidelines omit any recommendations and identifies this as a gap in evidence in need for further investigation.^[3,4]

5. 2014 AHA/ACC guidelines for non-STEMI also state that it is reasonable to continue BB therapy beyond 3 years in patients with normal LV function and without angina after ACS (IIa,B).^[3]

6. Routine long-term use of BB in patients after STEMI with preserved EF and no angina is a class Ib recommendation by the 2013 ACC/AHA guidelines and a Class IIa recommendation by ESC 2017 guidelines.^[5,6]

7. Holt et al. sought to investigate cardiovascular (CV) benefits associated with long term BB use in patients who are stable after MI with no residual angina or HF. They found that long-term BB treatment exceeding 3 months in patients optimally treated for MI with no HF or angina was not associated with reduction in CV death, recurrent MI, or a composite outcome of CV events.^[7]

8. Older adults have lower cardiac output, high peripheral vascular resistance, reduced renal blood flow and glomerular filtration rate, and low plasma renin activity compared to younger individuals. Because of these normal aging physiological changes, BB can exhibit more pronounced adverse effects in these patients and should be considered where applicable.^[8]

9. Therefore, in older adults who are completely revascularized and have no LV dysfunction or residual angina, long term BB therapy should be reassessed after 3 months since these drugs may cause adverse effects with no appreciable long-term benefits.

10. We recommend an individualized approach for the use of BB in older adults who have stable optimally treated ACS in the absence of HF, angina, and no other clear indication for BB use.

Management of CV conditions in addition to co-existing geriatric syndromes in elderly patients is challenging and often leads to polypharmacy which can lead to prescribing error, drug related adverse effects, drug interactions and hospital readmissions. In patients who are optimally revascularized and do not have symptoms of angina or LV dysfunction, BB discontinuation can be considered to reduce pill burden and adverse effects and improve medication adherence.

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