Effect of prophylactic antiarrhythmic therapy on time to implantable cardioverter-defibrillator discharge in patients with ventricular tachyarrhythmias.

Implantable cardioverter-defibrillators (ICDs) are being used increasingly for treatment of malignant ventricular tachyarrhythmias. However, ICD discharge is associated with significant morbidity. Antiarrhythmic therapy could reduce the frequency of ICD discharge, but its effect is uncertain. Thus, the effect of antiarrhythmic therapy was evaluated in a randomized trial. Thirty-four patients (32 men and 2 women, average age 60 years) who received an ICD for sustained ventricular tachycardia or fibrillation were entered in the trial and randomized to the best "drug" therapy (group 1; n = 17) or no therapy (group 2; n = 17). After the first ICD discharge, patients were to be crossed over to the alternative treatment arm. Twenty-nine patients had coronary artery disease. The induced arrhythmia was ventricular tachycardia in 33 patients and ventricular fibrillation in 1. Ejection fraction averaged 39%. The 2 groups were well balanced, without differences in demographic variables. In group 1, class I therapy was given to 9 patients and class III to 9. Beta blockade was used in a similar number of patients in groups 1 and 2 (n = 8 and 6, respectively). Time to the first shock or the end of follow-up averaged 143 days (range 1 to 609). During follow-up, 21 patients had a first ICD discharge event (11 in group 1, and 10 in group 2; p = 0.72). Event-free survival in each group was assessed by the Kaplan-Meier method, using the intention-to-treat approach. Overall median time to the first event was 134 days. Time to the first event did not differ between groups (p = 0.66; log-rank test).(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term (2 year) beneficial effects of beta-adrenergic blockade with bucindolol in patients with idiopathic dilated cardiomyopathy.

Beta-adrenergic blockade represents a promising therapeutic approach to idiopathic dilated cardiomyopathy. Bucindolol, a new beta-blocker, showed favorable effects in a short-term (3 month) trial in idiopathic dilated cardiomyopathy. To assess long-term response, 20 study patients (7 of 9 patients previously assigned to the placebo group and 13 of 14 patients previously assigned to bucindolol therapy) received long-term bucindolol therapy and were followed up for a mean of 23 +/- 4 months (range 17 to 30). The mean patient age was 49 years (range 29 to 66) and the median duration of disease was 11 months (range 1 to 190). Ten patients were in functional class II and 10 were in class III; 15 patients were men. At the end of the common follow-up time, all 20 patients were alive, 17 continued to receive bucindolol (mean dose 176 mg/day, range 25 to 200), and 2 underwent cardiac transplantation. Left ventricular ejection fraction increased from a baseline value of 25 +/- 8% to 35 +/- 13% (n = 19 pairs, p less than 0.001). Functional class improved in 12, was unchanged in 5 and deteriorated in 3 (p = 0.056). Exercise time was maintained (9.4 +/- 3.1 versus 9.1 +/- 3.5 min, n = 19, p = NS), as was maximal oxygen uptake (19.2 +/- 4.9 versus 18.8 +/- 5.7 ml/kg per min, n = 19, p = NS). Thus, long-term bucindolol therapy leads to substantial increases in ejection fraction and to improved functional class while stable exercise performance is maintained.(ABSTRACT TRUNCATED AT 250 WORDS)