Beta-Blockers for Spontaneous Coronary Artery Dissection (SCAD)
Beta-blockers should be initiated and continued indefinitely in all SCAD patients unless contraindicated, as they are the most important medication class for preventing recurrent SCAD events. 1, 2
Evidence Supporting Beta-Blocker Use in SCAD
The 2020 ESC Guidelines for Acute Coronary Syndromes explicitly state that beta-blockers should be considered as the preferred antihypertensive class in SCAD patients because they have been significantly associated with reduced risk of recurrent SCAD. 1 This recommendation is reinforced by the American Heart Association and American College of Cardiology, which designate beta-blockers as the cornerstone of SCAD medical therapy alongside aggressive blood pressure control. 2, 3
The strongest observational evidence comes from a prospective cohort of 327 SCAD patients followed for a median of 3.1 years, where beta-blocker therapy reduced recurrent SCAD risk by 64% (hazard ratio: 0.36; p = 0.004) in multivariate analysis. 4 This protective effect was independent of other cardiovascular medications and remained significant even after adjusting for hypertension, which itself increased recurrence risk 2.5-fold. 4
Regarding "Long-Acting" Beta-Blockers Specifically
The question about "long-acting" beta-blockers requires clarification: the critical distinction in SCAD is not about long-acting formulations per se, but rather about sustained, indefinite beta-blocker therapy for recurrence prevention. 2, 5
For chronic coronary disease with reduced ejection fraction (<50%), the 2023 AHA/ACC Guidelines recommend sustained-release metoprolol succinate, carvedilol, or bisoprolol with titration to target doses in preference to other beta-blockers. 1 However, these specific agent recommendations apply to patients with left ventricular dysfunction, not necessarily to the typical SCAD patient with preserved ejection fraction. 1
Practical Implementation
All SCAD patients should receive beta-blockers at discharge and continue them indefinitely unless specific contraindications exist (severe bradycardia, decompensated heart failure, high-degree AV block without pacemaker, severe reactive airway disease). 2, 5
The primary mechanism of benefit in SCAD differs from typical coronary artery disease: beta-blockers reduce arterial wall stress and blood pressure fluctuations that may precipitate dissection extension or recurrence, rather than primarily reducing myocardial oxygen demand. 1, 3
Aggressive blood pressure control is equally essential, with target blood pressure in the normal range using ACE inhibitors, ARBs, or non-dihydropyridine calcium channel blockers as additional agents if needed. 1, 2, 3 Hypertension is an independent predictor of recurrent SCAD and must be treated aggressively. 1, 4
Important Caveats
The evidence base for beta-blockers in SCAD comes entirely from observational studies, not randomized controlled trials. 4, 6 The BA-SCAD trial, a 2×2 factorial randomized trial comparing beta-blockers (yes/no) and antiplatelet duration in 600 SCAD patients, is currently ongoing and will provide definitive evidence. 7 However, given the strong observational signal for benefit and the established safety profile of beta-blockers, current guidelines uniformly recommend their use rather than waiting for trial results. 1, 2
Do not confuse SCAD management with standard post-MI care: the 2023 AHA/ACC Guidelines state that beta-blockers are not beneficial for reducing MACE in chronic coronary disease patients without prior MI or reduced ejection fraction. 1 However, SCAD is a distinct pathophysiologic entity where beta-blockers have demonstrated specific benefit for preventing recurrent dissection, not just treating ischemic heart disease. 1, 4