Structural adaptation of the heart in borderline hypertensives in response to blood pressure lowering with captopril.

OBJECTIVE

To determine whether treatment of borderline hypertension reverses the cardiac 'amplifier' effect associated with increased left ventricular mass.

DESIGN

Randomized, double-blind, placebo-controlled trial involving treatment for 6 months.

SETTING

Ambulant outpatients in a teaching hospital.

PARTICIPANTS

Recruited by local doctor referral or worksite screening. Average of two readings of entry blood pressures taken 1 week apart 140-160 mmHg (systolic) or 90-95 mmHg diastolic, or both. Twenty-six previously untreated males, mean +/- SD age 33 +/- 9.2 years with mean +/- SD blood pressure 138 +/- 7.4/90 +/- 7.0 mmHg entered and completed the study.

INTERVENTIONS: Twelve subjects received captopril, average dose 72 mg/day for 24 weeks, the remainder receiving placebo.

MAIN OUTCOME MEASURES: Echocardiographic left ventricular dimensions, mass and transmitral Doppler flow, as well as office, ambulatory and exercise blood pressure.

RESULTS

In the captopril group blood pressure was reduced significantly. Left ventricular mass decreased significantly from 205 to 195 g at 8 weeks and to 202 g at 24 weeks, returning to 232 g 4 weeks after treatment. Interventricular septum thickness fell significantly at 24 weeks. Doppler parameters did not alter. Baseline 8-h ambulatory blood pressure did not change with treatment. The reduction in peak exercise systolic blood pressure in the captopril group was not different from the change in the placebo group.

CONCLUSION

Blood pressure can be effectively lowered using captopril in young subjects with borderline hypertension. Treatment is well tolerated and leads to regression of left ventricular wall thickness and mass, suggesting that treatment of blood pressure elevations may be advisable at lower levels than currently recommended.