Acute haemodynamic effects of lisinopril and captopril in patients with severe congestive heart failure.

The acute haemodynamic effects of several equivalent dosages of lisinopril and captopril were compared in patients with severe class III or IV congestive heart failure. The evaluation was started with a low dose of 2.5 mg lisinopril o.d. or 6.25 mg captopril t.i.d. and subsequent daily increases to 5 and 10 mg lisinopril o.d. or 12.5 and 25 mg captopril t.i.d. Captopril had an earlier onset of action compared to lisinopril and caused larger diurnal fluctuations of the haemodynamic parameters. Lisinopril provoked a more pronounced decrease in pulmonary capillary wedge pressure (PCWP) than captopril and only lisinopril increased the cardiac index significantly. Side-effects of hypotension or increase in serum creatinine leading to withdrawal according to protocol were noted in 3 patients on each drug. Increases in dosage caused very little increase in haemodynamic effect, suggesting that complete suppression of the angiotensin-converting enzyme may not be necessary for an optimal clinical response.