Captopril and spironolactone therapy for refractory congestive heart failure

Short- and long-term clinical effects of the angiotensin-converting enzyme (ACE) inhibitor captopril in severe congestive heart failure (CHF) were evaluated during a 3-year open study of 124 inpatients with New York Heart Association (NYHA) functional class III or IV CHF refractory to treatment with cardiac glycosides and high doses of loop diuretics. Captopril was added to each patient's regimen, which comprised combinations of furosemide (124 patients), digitalis (117 patients), and spironolactone (90 patients). By the end of the first month of captopril administration, improvement in NYHA functional class was seen in 89 patients (72%). During the first year of captopril treatment, the number of hospital admissions and hospital days declined significantly (p < 0.001) and functional class improved significantly (p < 0.001). Although most patients tolerated captopril well, 44% experienced hypotension, which in 10% of patients necessitated termination of captopril therapy. Although mean serum potassium levels tended to increase, serious hyperkalemia did not occur. After 1 year, a subset of 30 patients who had not initially received spironolactone deteriorated clinically and manifested increasing urinary aldosterone levels. Hypotension precluded increasing the captopril dose, but introduction of spironolactone improved clinical status in this cohort. The results suggest that rational therapy for severe CHF includes addition of the aldosterone antagonist spironolactone to low doses of captopril (or another ACE inhibitor) and high doses of loop diuretics, provided renal function is adequate.