JAMA：利尿剂可延长高血压患者生存时间

http://www.medpagetoday.com/Cardiology/Hypertension/30327

根据日前发表在JAMA上的一项研究，高血压患者每服用一个月的利尿剂降压药，平均可延长一天的寿命。文中研究的对象是老年单纯性收缩期高血压。。。

Diuretics Yield Long-Term Survival Benefit


Older patients with isolated systolic hypertension gained an extra day of life expectancy for every month of treatment with diuretic-based stepped care, according to long-term follow-up of a randomized trial.

Patients randomized to chlorthalidone for 4.5 years had a 105-day improvement in all-cause mortality and a 158-day gain in freedom from cardiovascular death compared with placebo treatment.

The 22-year follow-up data add an exclamation point to short-term survival benefits observed in multiple other trials, investigators reported in the Dec. 21 issue of JAMA.

"This gain in life expectancy is important because it occurred among persons with a mean age of 72 years at baseline," John B. Kostis, MD, of the University of Medicine and Dentistry of New Jersey in New Brunswick, and co-authors wrote in their comments.

"Reporting that each month of antihypertensive therapy was associated with one day prolongation of life expectancy free from cardiovascular death is a strong message that may result in increased patient adherence to drug therapy and decrease the degree of therapeutic inertia by healthcare providers," they added.

The findings came from the Systolic Hypertension in the Elderly Program (SHEP), which assessed the effect of 4.5 years of treatment with chlorthalidone on the risk of stroke in older patients with isolated systolic hypertension.

As reported more than 20 years ago, the primary results showed a 36% lower risk of stroke in patients randomized to active therapy versus placebo (JAMA 1991; 265: 3255-3264). The chlorthalidone arm also had substantial reductions in hospitalization for heart failure and coronary heart disease events.

Despite the range of clinical benefits demonstrated with active treatment, SHEP failed to show improvement in survival in the chlorthalidone arm.

When randomized treatment ended, patients in both treatment groups were advised to start or continue active therapy.

Kostis and colleagues returned to the SHEP database to see whether a survival benefit had emerged after 22 years of follow-up.

Begun in 1984, SHEP involved 4,736 patients 60 and older who had isolated systolic hypertension, defined at the time as systolic blood pressure ≥160 mm Hg and diastolic pressure <90 mm Hg.

The primary objective of the analysis was to determine the net gain in life expectancy free of cardiovascular death and to compare median survival free of cardiovascular death.

During follow-up, mean systolic blood pressure remained 26 mm Hg lower compared with baseline, and diastolic pressure 9 mm Hg lower in patients randomized to active therapy. Corresponding values for the placebo group were 15 and 4 to 5 mm Hg.

After 22 years, 2,851 (60.2%) of SHEP participants had died, 59.9% in the chlorthalidone arm and 60.5% in the placebo group. The authors found that 294 (12.4%) deaths in the placebo arm resulted from CHD and 110 (4.6%) from stroke, compared with 13.6% and 5.6%, respectively, in the placebo arm.

Because fewer than half of the participants in the study died of cardiovascular causes, 70th percentile survival was substituted for median survival.

The 158-day improvement in freedom from cardiovascular death was statistically significant (P=0.009), but the 105-day gain in overall survival was not (P=0.07). The chlorthalidone group had a cardiovascular mortality of 28.3% versus 31.0% in the placebo group (P=0.02).

The time to 70th percentile survival for all-cause mortality was 0.56 years longer in the chlorthalidone group (11.53 versus 10.98 years, P=0.03) and 1.41 years longer for survival free of cardiovascular death (P=0.01).

Limitations of the study included: observational follow-up after the end of the randomized trial; absence of information on intervening antihypertensive therapy, lipid-lowering, diabetes control, and surgical or device interventions; lack of data on nonfatal cardiovascular events; and wide confidence intervals.

"It can be argued that the results of our analysis would be expected because with longer follow-up, reductions in nonfatal cardiovascular events would result in decreased mortality, especially from cardiovascular causes," the authors wrote in their discussion of the results.

"Our study demonstrating this association between treatment and long-term benefits supports this hypothesis and provides a quantitative estimate of the mortality benefit," they added. "The results ... may underestimate the benefit because of crossover between active and placebo groups."

咱们国内的文献不是说高血压患者长期服用利尿剂会造成对肾脏的严重损害吗？

要综合考虑。