Comparison of active treatment and placebo in older Chinese patients with isolated systolic hypertension. Systolic Hypertension in China (Syst-China) Collaborative Group.

BACKGROUND

Isolated systolic hypertension occurs in around 8% of Chinese people aged 60 years or older. In 1988, the Systolic Hypertension in China (Syst-China) Collaborative Group started to investigate whether active treatment could reduce the incidence of stroke and other cardiovascular complications in older patients with isolated systolic hypertension.

METHODS

All patients were initially started on masked placebo. After stratification for centre, sex and previous cardiovascular complications, alternate patients (n=1253) were assigned nitrendipine at 10-40 mg daily, with the addition of captopril at 12.5-50.0 mg daily or hydrochlorothiazide at 12.5-50.0 mg daily, or both, if a sufficient blood pressure fall was not obtained. In the remaining 1141 control patients, matching placebos were administered similarly.

RESULTS

At entry, sitting blood pressure averaged 170.5 mmHg systolic and 86.0 mmHg diastolic, age averaged 66.5 years and total serum cholesterol was 5.1 mmol/l. After 2 years of follow-up, sitting systolic and diastolic blood pressures had fallen by 10.9 mmHg and 1.9 mmHg in the placebo group and by 20.0 mmHg and 5.0 mmHg in the active treatment group. The intergroup differences were 9.1 mmHg systolic (95% confidence interval 7.6-10.7 mmHg ) and 3.2 mmHg diastolic (95% confidence interval 2.4-4.0). Active treatment reduced total strokes by 38% (from 20.8 to 13.0 endpoints per 1000 patient-years, P=0.01), all-cause mortality by 39% (from 28.4 to 17.4 endpoints per 1000 patient-years, P=0.003), cardiovascular mortality by 39% (from 15.2 to 9.4 endpoints per 1000 patient-years, P=0.03), stroke mortality by 58% (from 6.9 to 2.9 endpoints per 1000 patient-years, P=0.02), and ail fatal and nonfatal cardiovascular endpoints by 37% (from 33.3 to 21.4 endpoints per 1000 patient-years, P=0.004).

CONCLUSIONS

Antihypertensive treatment prevents stroke and other cardiovascular complications in older Chinese patients with isolated systolic hypertension. Treatment of 1000 Chinese patients for 5 years could prevent 55 deaths, 39 strokes or 59 major cardiovascular endpoints.