[Hypertensive hypertrophy of the left ventricle: its regression in hypertensive patients with different profiles of plasma renin activity, treated with enalapril].

STUDY OBJECTIVE

To determine the action of enalapril maleate in cardiac mass and ventricular performance; to investigate virtual differences of anti-hypertensive action, and regression of left ventricular hypertrophy, between subgroups of patients with different profiles of plasma renin activity (PRA).

DESIGN

Randomized, single-blind, placebo-controlled study, along 14 weeks, the last 12 under active treatment with enalapril maleate.

SETTING

Outpatient clinics of an university department of Internal Medicine and Cardiology.

PATIENTS

Sequential series of twenty patients with mild to moderate essential hypertension. Two patients were lost to follow-up. Eighteen patients completed the study. Seventeen out of them were studied for plasma renin activities, and echocardiographic measurements were performed in ten, during the 2 weeks placebo period, and by the end of active treatment. No patients were excluded because of side-effects.

INTERVENTION

After a 2-weeks washout period, enalapril maleate has been given in a single daily dose of 20 mg, at bedtime. In 14 patients the dosage was elevated to 40 mg once daily and, in 5 out of these, 12.5 mg hydrochlorothiazide once a day has been added.

MEASUREMENTS AND MAIN RESULTS

The mean of systolic/diastolic sitting blood pressures was reduced from 171.6/112 to 151.6/98.1 mmHg (p less than 0.001). The mean of systolic/diastolic standing blood pressures lowered from 167.8/113.7 to 148.6/99.6 mmHg (p less than 0.001). No significant differences were found between blood pressure reductions in 5 patients with elevated PRA, 5 patients with slightly elevated PRA, and 7 patients with normal or low PRA. The analysis of echocardiographic measurements revealed regression of left ventricular hypertrophy (LVH) and, in one patient who had no criteria of LVH, actually occurred reduction of the thickness of ventricular walls. No unfavourable influence over ventricular function indices, neither systolic nor diastolic, was found. End-systolic stress and inotropic activity remained unchanged. The tolerability of the study drug was very good.

CONCLUSIONS

Enalapril maleate appears, in this study, an effective anti-hypertensive compound. Its therapeutic action seems independent of the plasma renin activity profile. The drug induced regression of left ventricular hypertrophy after a period of 12 weeks of treatment, and did not promote any unfavourable influence over ventricular functions indices. Inotropic activity and end-systolic stress were not modified. The tolerability was very good.