Abstract
BACKGROUND: Beta-blockers are a cornerstone of heart failure management, but comparative effectiveness data for different beta-blockers in patients with mechanical circulatory support remain limited. This study aimed to compare clinical outcomes between carvedilol and metoprolol in patients with left ventricular assist devices (LVADs). METHODS: We performed a retrospective cohort study using the TriNetX Research Network (Cambridge, MA: TriNetX, LLC), a global federated health research platform providing access to electronic medical records across 104 healthcare organizations. Patients with left ventricular assist devices (ICD-10 code Z95.81) who were prescribed either carvedilol or metoprolol were identified. After propensity score matching for baseline characteristics, including cardiac and non-cardiac comorbidities, cohorts of 5,166 patients each receiving carvedilol or metoprolol were analyzed. The primary outcome was all-cause mortality. Secondary outcomes included heart failure exacerbation, cardiac arrest, cardiogenic shock, sepsis, acute kidney injury, atrial fibrillation, ventricular tachycardia, and sick sinus syndrome. Outcomes were analyzed using Kaplan-Meier survival analysis with hazard ratios (HR) and 95% confidence intervals (CI) over a one-year follow-up period. RESULTS: In this propensity-matched cohort study, patients receiving carvedilol demonstrated significantly lower all-cause mortality compared to the metoprolol group (15.4% vs. 17.0%; HR: 0.879, 95% CI: 0.799-0.968; p=0.009). Carvedilol was also associated with reduced incidence of cardiac arrest (5.0% vs. 6.1%; HR: 0.799, 95% CI: 0.677-0.942; p=0.007), cardiogenic shock (17.7% vs. 21.0%; HR: 0.817, 95% CI: 0.748-0.892; p<0.001), sepsis (8.8% vs. 10.4%; HR: 0.821, 95% CI: 0.724-0.930; p=0.002), and atrial fibrillation (27.3% vs. 30.7%; HR: 0.850, 95% CI: 0.792-0.914; p<0.001). However, patients in the carvedilol group experienced higher rates of heart failure exacerbation (71.3% vs. 65.9%; HR: 1.149, 95% CI: 1.097-1.204; p<0.001) and acute kidney injury (31.8% vs. 28.1%; HR: 1.132, 95% CI: 1.055-1.214; p=0.001). No significant difference was observed in the incidence of sick sinus syndrome between the two groups (8.6% vs. 8.8%; HR: 0.951, 95% CI: 0.834-1.084; p=0.450). The difference in ventricular tachycardia rates was not clinically significant despite statistical significance (23.2% vs. 22.9%; HR: 0.991, 95% CI: 0.915-1.074; p<0.001). CONCLUSION: In patients with left ventricular assist devices, carvedilol was associated with lower all-cause mortality and reduced incidence of several important cardiovascular complications compared to metoprolol, despite higher rates of heart failure exacerbation and renal complications. These findings suggest that carvedilol may be preferred over metoprolol in selected LVAD patients, though individualized consideration of heart failure status and renal function remains important. Further prospective studies are warranted to confirm these findings and optimize beta-blocker selection in this high-risk population.