Influence of ramipril on plasma atrial natriuretic peptide, antidiuretic hormone, angiotensin II and aldosterone in patients with chronic congestive heart failure.

In an open trial 5 mg ramipril daily for 2 weeks was administered to 11 patients with congestive heart failure. 24-hour plasma profiles of atrial natriuretic peptide (ANP), antidiuretic hormone (ADH), angiotensin II (Ang II) and aldosterone (Aldo) were determined before and on days 1 and 15 of ramipril treatment, respectively. Urinary sodium excretion was also measured at the same time points. There were no relevant differences in the 24-hour profiles of ANP and ADH. Ang II values dropped as expected on the first day of ramipril treatment from 11.2 pg/ml to 2.9 pg/ml at 3 h post administration and from 6.7 pg/ml (predose) to 1.8 pg/ml at 2 h post administration on day 15. Plasma aldosterone values increased slightly from day 1 to day 15, sodium excretion increased from 125.9 mmol to 166.5 mmol/24 h; however, both changes in the 24-hour profiles were nonsignificant. A clinically relevant improvement in the severity of CHF was observed. From a total of 121 reported symptoms according to McKee et al., 35 showed an improvement; 81 remained unchanged, in only 5 symptoms a deterioration was observed. According to the NYHA-classification 5 patients improved from grade III to II, 6 remained unchanged.

CONCLUSIONS

ACE inhibition does not induce changes in ANP or ADH levels in the resting state while Ang II decreases. A slight increase in aldosterone levels may be due to increased sodium excretion.