[The midterm inefficacy of 2 different dosages of chlorthalidone (50 and 25 mg/day) in the regression of left ventricular mass in arterial hypertension].

BACKGROUND: To evaluate the antihypertensive efficacy at rest and under exercise, and the modifications induced on the left ventricular mass in patients treated with two different doses of a diuretic. METHODS: Fifty hypertensive males, mean age 51 years, received during nine months 50 mg/day of chlortalidone and thirteen 25 mg/day for the next nine months. Baseline tension control and echocardiogram and each three months after starting therapy during the two phases of the study were performed. Thickness of the interventricular septum and posterior left ventricular wall in mm, left ventricular mass index in g/m2 were determined. RESULTS: The baseline septum was 15 +/- 3.3 mm, 14.6 +/- 3.1 mm at 9 months and 14.5 +/- 2.9 mm at 18 months, the posterior wall was 14.1 +/- 3.1 mm at baseline, 13.7 +/- 2.9 mm at 9 months and 13.6 +/- 2.9 mm at 18 months. The left ventricular mass index was 153 +/- 45 g/m2 at baseline, 146 +/- 36 g/m2 at 9 months and 144 +/- 39 g/m2 at 18 months. The antihypertensive efficacy at rest and under exertion was similar for the two doses of chlortalidone. CONCLUSIONS: After nine months of therapy the two doses of chlortalidone (50 and 25 mg/day) failed in reducing left ventricular mass. However, the design of the study and the small number of subjects enrolled introduce several important limitations to both the interpretation of our results and conclusions.