Cardiology · Medical Literature
A meta-analysis of randomized controlled trials on atenolol's impact on postoperative atrial fibrillation in adults undergoing cardiac surgery.
Abstract
Prior research has conducted a limited number of studies on the efficacy of atenolol in preventing atrial fibrillation following cardiac surgery (CS). Consequently, a comprehensive evaluation and meta-analysis were undertaken to assess the effectiveness and safety of atenolol in patients undergoing CS for the prevention of postoperative atrial fibrillation (POAF). A meta-analysis of randomized controlled trials was performed. Searches were conducted across multiple databases up to December 1, 2024. The primary focus was the incidence of POAF. Risk ratios (RRs) for treatment effects on dichotomous variables were calculated. The data analysis encompassed 6 randomized controlled trials involving a total of 870 patients. The meta-analysis revealed that atenolol significantly reduces the incidence of POAF in adult patients undergoing CS (RR, 0.55; 95% confidence interval [CI]: 0.32-0.93; P = .03) with moderate heterogeneity (I2 = 57%; P = .10). Atenolol did not demonstrate superiority over sotalol in reducing POAF (RR, 2.39; 95% CI: 1.41-4.04; P = .001) with moderate heterogeneity (I2 = 40%; P = .19). Furthermore, no significant difference was observed between atenolol and the control group (comprising propafenone, metoprolol, nebivolol, and digoxin) in the prevention of POAF (RR, 1.28; 95% CI: 0.76-2.16; P = .35) with moderate heterogeneity (I2 = 43%; P = .15). Recent studies suggest that atenolol could be a safe and effective intervention for the prevention of POAF in adult patients undergoing CS.
Clinical relevance
Postoperative atrial fibrillation (POAF) is one of the most common and morbid complications following cardiac surgery, associated with increased stroke risk, prolonged ICU stay, and higher mortality. Despite widespread beta-blocker use in perioperative cardiac care, the specific efficacy of atenolol — a selective beta-1 blocker — for POAF prophylaxis had not been rigorously synthesized. This meta-analysis addresses that evidence gap by pooling RCT-level data, providing specialists with a more definitive signal on atenolol's role in this high-risk population.
Key findings
1. Atenolol significantly reduced the incidence of POAF compared to placebo/no treatment in adult cardiac surgery patients (RR 0.55; 95% CI: 0.32–0.93; P = .03), representing an approximately 45% relative risk reduction. 2. The meta-analysis pooled data from 6 RCTs encompassing a total of 870 patients, providing the most comprehensive synthesis of atenolol-specific POAF prevention data to date. 3. Moderate heterogeneity was observed in the primary efficacy analysis (I² = 57%; P = .10), indicating meaningful variability across trials that warrants cautious generalization. 4. Atenolol was inferior to sotalol in preventing POAF (RR 2.39; 95% CI: 1.41–4.04; P = .001), suggesting sotalol confers superior prophylactic benefit in the cardiac surgery setting, with low-to-moderate heterogeneity (I² = 40%; P = .19). 5. No statistically significant difference was detected between atenolol and an active comparator group (propafenone, metoprolol, nebivolol, and digoxin) for POAF prevention (RR 1.28; 95% CI: 0.76–2.16; P = .35; I² = 43%), though the confidence interval does not exclude a clinically meaningful disadvantage for atenolol. 6. The authors characterize atenolol as a 'safe and effective intervention' for POAF prophylaxis; however, no specific safety outcome data (e.g., bradycardia, hypotension rates, or adverse event RRs) were reported in the abstract, limiting quantitative safety conclusions.
Practice implications
Atenolol may be considered a viable perioperative prophylactic agent for POAF in adult patients undergoing cardiac surgery when first-line agents such as sotalol are contraindicated (e.g., significant renal impairment, QTc prolongation, or prior torsades de pointes), given sotalol's demonstrated superiority in this meta-analysis. Clinicians should not preferentially substitute atenolol for other established beta-blockers (metoprolol, nebivolol) or antiarrhythmics (propafenone) solely based on this evidence, as no significant efficacy difference was demonstrated among active comparators. The moderate heterogeneity across trials (I² up to 57%) underscores the need for individualized patient selection, careful perioperative hemodynamic monitoring, and adherence to institutional POAF prophylaxis protocols pending larger, adequately powered head-to-head RCTs.