Effect of spironolactone on ventricular arrhythmias in congestive heart failure secondary to idiopathic dilated or to ischemic cardiomyopathy

Epidemiologic studies have shown an important increase in the high mortalit y of patients with congestive heart failure (CHF) despite optimal medical m anagement. Ventricular arrhythmia was recognized as the mast common cause o f death in this population. Electrolyte imbalance, myocardial fibrosis, lef t ventricular dysfunction, and inappropriate neurohumoral activation are pr esumed responsible for sudden cardiac death. In this study, we focused on t he deleterious effects of the overproduction of aldosterone that occurs in patients with CHF, Secondary hyperaldersteronism can be part of several fac tors thought to be responsible for sudden cardiac death. We randomized 35 p atients (32 men, aged 48 +/- 9 years) with systolic dysfunction (ejection f raction 33 +/- 5%) and New York Heart Association class III CHF secondary t o dilated or ischemic cardiomyopathy into 2 groups. The treatment group rec eived spironolactone, an aldosterone receptor antagonist, along with standa rd medical management using furosemide, angiotensin-converting enzyme inhib itors, and digoxin. The control group received only the standard medical tr eatment. Halter monitoring was used to assess the severity of ventricular a rrhythmia. After 20 weeks, patients who received spironolactone had a reduc ed hourly frequency of ventricular premature complexes (VPCs) (65 +/- 18 VP Cs/hour at week 0 and 17 +/- 9 VPCs/hour at week 16) and episodes of nonsus tained ventricular tachycardia (VT) (3.0 +/- 0.8 episodes of VT/24-hour per iod at week 0, and 0.6 +/- 0.3 VT/24-hour period at week 16). During monito red treadmill exercise, a significant improvement in ventricular arrhythmia was found in the group receiving spironolactone (39 +/- 10 VPCs at week 0, and 6 +/- 2 VPCs at week 16). These findings suggest that aldosterone may contribute to the incidence of ventricular arrhythmia in patients with CHF, and spironolactone helps reduce this complication. (C) 2000 by Excerpta Me dico, Inc.