What is the role of Propranolol (a beta blocker) in Coronary Artery Disease (CAD) management?

From the Guidelines

Propranolol is a beneficial beta-blocker in coronary artery disease (CAD) management, reducing myocardial oxygen demand and improving symptoms, but its use should be guided by the most recent and highest quality evidence, such as the 2024 ESC guidelines for the management of chronic coronary syndromes 1.

Key Points

• The typical starting dose of propranolol is 10-20 mg three times daily, which can be gradually increased to 80-320 mg daily based on patient response and tolerance.
• Propranolol helps prevent angina attacks by decreasing heart rate and contractility, thereby reducing myocardial oxygen consumption.
• In post-myocardial infarction patients, propranolol reduces mortality risk and prevents reinfarction.
• Propranolol works by blocking beta-adrenergic receptors, preventing catecholamines from increasing heart rate and contractility.
• Common side effects include fatigue, bradycardia, hypotension, and bronchospasm.
• Propranolol should be used cautiously in patients with asthma, COPD, heart failure, or diabetes.

Important Considerations

• The clinical benefit of beta-blockers in patients with CAD without prior MI and with normal LVEF is largely unknown in the absence of evidence from RCTs 1.
• The main findings of some observational studies addressing this issue are summarized in the Supplementary data of the 2024 ESC guidelines 1.
• The clinical benefit of beta-blockers in post-ACS patients with reduced LVEF is supported by solid evidence 1.
• There are no large RCTs supporting the prescription of beta-blockers after uncomplicated ACS in patients with LVEF >40% 1.

Monitoring and Management

• Regular monitoring of heart rate, blood pressure, and symptoms is essential for optimal management.
• Propranolol should not be abruptly discontinued as this may worsen angina or trigger arrhythmias; dosage should be gradually reduced over 1-2 weeks when stopping treatment.
• The aim of beta-blocker therapy should be to lower resting heart rate to 55–60 beats per minute (b.p.m.) for symptomatic relief of angina 1.

From the FDA Drug Label

In angina pectoris, propranolol generally reduces the oxygen requirement of the heart at any given level of effort by blocking the catecholamine-induced increases in the heart rate, systolic blood pressure, and the velocity and extent of myocardial contraction The net physiologic effect of beta-adrenergic blockade is usually advantageous and is manifested during exercise by delayed onset of pain and increased work capacity

Propranolol can be used in Coronary Artery Disease (CAD) to reduce the oxygen requirement of the heart and increase work capacity. The mechanism of action involves blocking catecholamine-induced increases in heart rate, systolic blood pressure, and myocardial contraction, which is usually advantageous and manifested by delayed onset of pain and increased work capacity during exercise 2.

From the Research

Propranolol Use in Coronary Artery Disease (CAD)

• Propranolol, a beta-adrenergic blocker, has been reported to reduce myocardial oxygen consumption and symptoms of myocardial ischemia in patients with CAD 3.
• However, propranolol can also potentiate coronary artery vasoconstriction in some patients with CAD, possibly mediated by unopposed alpha-adrenergic vasomotor tone 3.
• The use of propranolol in patients with CAD can increase diastolic time, allowing more time for coronary perfusion, which may be an important factor in its beneficial effect 4.

Benefits and Risks of Propranolol in CAD

• Propranolol can increase diastolic time, which may improve coronary perfusion and reduce angina symptoms 4.
• However, the use of propranolol in patients with CAD and preserved ejection fraction may not have a clear mortality benefit, and its long-term adverse outcomes may outweigh its antianginal benefits 5.
• Recent studies have questioned the beneficial effect of beta-blockers, including propranolol, in the management of patients with stable ischemic heart disease and myocardial infarction 6.

Guidelines and Recommendations

• Current guidelines recommend the use of beta-blockers, including propranolol, in the treatment of hypertension in patients with CAD, along with ACE inhibitors or angiotensin receptor blockers (ARBs) 7.
• The guidelines also recommend the use of long-acting nitrates as effective antianginal and anti-ischemic drugs, and calcium-channel blockers (CCBs) may be added if angina persists despite beta-blockers and long-acting nitrates 7.