Carvedilol vs. Metoprolol and Risk of Arrhythmias Among ICD Recipients

Quick Takes

  • In patients with HF who receive a primary prevention ICD, the risk of developing atrial arrhythmia is significantly influenced by the type of beta-blocker treatment. Carvedilol can significantly reduce the risk of atrial arrhythmias when compared to metoprolol.
  • Among HF patients receiving an ICD therapy, carvedilol may have antiarrhythmic properties associated with decreased risk of developing atrial arrhythmias and inappropriate ICD shocks when compared to metoprolol.

Study Questions:

What is the effect of metoprolol versus carvedilol on the risk of atrial tachyarrhythmia (ATA) and ventricular arrhythmia (VA) in heart failure (HF) patients with an implantable cardioverter-defibrillator (ICD)?


This study pooled primary prevention ICD recipients from five ICD trials (MADIT-II, MADIT-CRT, MADIT-RIT, MADIT-RISK, and RAID). Multivariate regression models were used to evaluate the risk of ATA, inappropriate ICD shocks, and fast VA by beta-blocker type.


Among 4,194 patients, 2,920 (70%) were prescribed carvedilol and 1,274 (30%) metoprolol. The cumulative incidence of ATA at 3.5 years was 11% in patients treated with carvedilol versus 15% in patients taking metoprolol (p = 0.003). Multivariate analysis showed that carvedilol treatment was associated with a 35% reduction in the risk of ATA (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.53-0.81; p < 0.001) when compared to metoprolol, and with a corresponding 35% reduction in the risk of inappropriate ICD shocks (HR, 0.65; 95% CI, 0.47-0.89; p = 0.008). Carvedilol versus metoprolol was also associated with a 16% reduction in the risk of fast VA (not statistically significant).


The authors conclude that HF patients with ICDs on carvedilol treatment experience a significantly lower risk of ATA and inappropriate ICD shocks when compared to treatment with metoprolol.


This retrospective study of HF patients with primary prevention ICDs shows that those who are treated with carvedilol experience a significantly lower risk of ATA and inappropriate ICD shocks when compared to those treated with metoprolol. There also is a trend toward a reduction in fast VA risk among patients treated with carvedilol versus metoprolol. This study adds to the accumulating evidence suggesting that patients taking carvedilol seem to do better than those on metoprolol. The examined studies were not designed to compare outcomes of patients on carvedilol to those on metoprolol and the patients in these studies were not receiving present-day therapies such as sacubitril/valsartan and sodium-glucose cotransporter-2 inhibitors. Future studies are needed to prospectively evaluate the effect carvedilol and metoprolol have on arrhythmic outcomes in the contemporary era.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure

Keywords: Adrenergic beta-Antagonists, Arrhythmias, Cardiac, Defibrillators, Implantable, Heart Failure, Primary Prevention

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