Clinical trials have shown that b-adrenergic blocking drugs are effective and well tolerated in patients with mild to moderate congestive heart failure. Carvedilol is a mild b1-selective adrenergic blocking agent with vasodilating properties due to a blocker and antioxidant and anti-proliferative properties. This study assessed the efficacy and safety of carvedilol in patients with moderate to severe congestive heart failure caused by idiopathic dilated cardiomyopathy.

We enrolled 27 patients with moderate to severe congestive heart failure with a left ventricular ejection fraction of 35% by MUGA scan. Each patient was randomly assigned to either control (n-9) or carvedilol (n-18, target dose 25 mg bid) for 6 months while background therapy with digoxin, diuretics, and ACE inhibitor remained constant.

Compared to the control group, patients in the carvedilol group showed significant increase of left ventricular ejection fraction (p<0.05). In addition, patients in the carvedilol group had a tendency to show a decrease in left ventricular end-diastolic dimension and heart rate. Also, the carvedilol group had a greater frequency of symptomatic improvement than the control group. There was neither serious side effects nor hospitalization.

These finding indicate that carvedilol produces important clinical benefits in patients with moderate to severe heart failure treated with digoxin, diuretics, and ACE inhibitor without serious side effects.