What should be the next antihypertensive medication for a patient with hypertension and a prior myocardial infarction who is already taking a calcium channel blocker and an angiotensin receptor blocker?

Third-Line Antihypertensive Agent for Post-MI Patient on CCB and ARB

Add a beta-blocker as the third-line agent for this patient with prior myocardial infarction who is already on a calcium channel blocker and angiotensin receptor blocker. 1

Why Beta-Blockers Should Have Been First-Line

The current regimen is suboptimal because beta-blockers and ACE inhibitors (or ARBs) should be the foundational therapy for any hypertensive patient with prior MI, not third-line agents. 1

• Beta-blockers reduce all-cause mortality by 23% after MI and lower the risk of recurrent infarction through both cardioprotective effects and blood pressure reduction. 1
• ACE inhibitors or ARBs reduce cardiovascular mortality by 20-22% in post-MI patients, especially those with left ventricular systolic dysfunction. 1
• The American College of Cardiology and American Heart Association explicitly recommend beta-blockers plus ACE inhibitors (or ARBs) as first-line therapy for hypertensive patients with CAD and prior MI. 1

The Correct Third-Line Agent: Beta-Blocker

Since this patient is already on an ARB (appropriate) and a CCB (less ideal as initial therapy), adding a beta-blocker now is the priority to provide the proven mortality benefit. 1

• Use guideline-directed medical therapy (GDMT) beta-blockers: carvedilol, metoprolol succinate, bisoprolol, nadolol, propranolol, or timolol. 1
• Beta-blocker therapy should be continued beyond 3 years post-MI for long-term hypertension management and secondary prevention. 1
• In patients with coronary artery disease, beta-blockers remain essential despite recent controversies about their use in uncomplicated hypertension. 2

Alternative Third-Line Options (If Beta-Blocker Contraindicated)

If the patient has absolute contraindications to beta-blockers (severe bradycardia, decompensated heart failure, second- or third-degree heart block, reactive airway disease), consider these alternatives:

• Thiazide or thiazide-like diuretic if volume overload or inadequate BP control persists. 1, 3
• Mineralocorticoid receptor antagonist (MRA) such as eplerenone or spironolactone if the patient has left ventricular ejection fraction ≤40% with heart failure or diabetes—this reduces total mortality by approximately 15%. 1
• Additional dihydropyridine CCB (different from the current CCB) can be added if angina persists, though this does not provide the mortality benefit of beta-blockers. 1

Blood Pressure Target

• Target BP is <130/80 mmHg for patients with coronary artery disease and hypertension. 1
• Achieving this target is associated with a 25% reduction in cardiovascular events and 27% decrease in all-cause mortality. 1
• Exercise caution when lowering diastolic BP below 60 mmHg, especially in patients aged ≥60 years or those with diabetes, as overly low diastolic pressure can be harmful. 1

Critical Pitfall to Avoid

• Never combine an ACE inhibitor with an ARB—this patient is already on an ARB, so do not add an ACE inhibitor. This combination increases adverse events (hyperkalemia, hypotension, renal dysfunction) without additional cardiovascular benefit. 1, 3

Monitoring Requirements

• Monitor serum creatinine and potassium within 7-14 days after adding any renin-angiotensin system blocker or MRA, then at least annually. 3
• Assess BP monthly until the target of <130/80 mmHg is achieved. 3
• Watch for bradycardia when initiating beta-blocker therapy, especially if the patient is on other rate-lowering agents. 4