Captopril and the diuretic requirements in moderate and severe chronic heart failure.

The effect of captopril on diuretic requirements was assessed in 16 patients with moderate (13 NYHA Class III, 1 NYHA Class II) or severe (3 NYHA Class IV) stable non-oedematous chronic heart failure. The dose of diuretics was halved before captopril was started and follow-up was continued for two months. In all three patients in NYHA Class IV the diuretic dosage had to be increased to a dose close to, or the same as, the original dose of diuretics in order to keep them from congestive heart failure. One patient improved on the new regime but gained 3.5 kg in weight during follow-up. Of the 13 patients with moderate heart failure, seven showed an improvement in symptoms and exercise duration on the combination of captopril and the lower dose of diuretics (mean 6.9 to 12.5 min, P less than 0.001); two patients did not improve and gained 1.7 kg and 2.3 kg in weight, respectively; three patients required the original dose of diuretics to keep them from congestive heart failure and one patient lost weight on the reduced dose of diuretics but showed no improvement clinically or on treadmill exercise testing. Thus captopril does not have a diuretic sparing effect in patients with severe chronic heart failure. Those treated need the original dose of diuretics for maximal symptomatic benefit. Captopril does have a diuretic sparing effect in some patients with moderate chronic heart failure.