The Role of Diastolic Blood Pressure When Treating Isolated Systolic Hypertension

TLDR

To assess the role of treated diastolic blood pressure in stroke, coronary heart disease, and cardiovascular disease among patients with isolated systolic hypertension and to determine whether excessively low DBP can be avoided by more careful titration of antihypertensive therapy while maintaining systolic control. An analysis of 4,736 participants from the randomized, multicenter, double‑blind SHEP trial used Cox proportional hazards regression with DBP and SBP as time‑dependent covariables. In the active treatment group, a 5 mm Hg decrease in DBP increased risk of stroke (RR 1.14), CHD (RR 1.08), and CVD (RR 1.11), yet patients receiving ISH treatment never performed worse than placebo in terms of CVD events, indicating that some may be overtreated while others may be treated to a level that uncovers subclinical disease.

Abstract

<h3>Objective</h3> To assess the role of treated diastolic blood pressure (DBP) level in stroke, coronary heart disease (CHD), and cardiovascular disease (CVD) in patients with isolated systolic hypertension (ISH). <h3>Design</h3> An analysis of the 4736 participants in the Systolic Hypertension in the Elderly Program (SHEP) was undertaken. The SHEP was a randomized multicenter double-blind outpatient clinical trial of the impact of treating ISH in men and women aged 60 years and older. <h3>Main Outcome Measures</h3> Cox proportional hazards regression analysis, with DBP and systolic blood pressure (SBP) as time-dependent covariables. <h3>Results</h3> After adjustment for the baseline risk factors of race (black vs other), sex, use of antihypertensive medication before the study, a composite variable (diabetes, previous heart attack, or stroke), age, and smoking history (ever vs never) and adjustment for the SBP as a time-dependent variable, we found, for the active treatment group only, that a decrease of 5 mm Hg in DBP increased the risk for stroke (relative risk, [RR], 1.14; 95% confidence interval [CI], 1.05-1.22), for CHD (RR, 1.08; 95% CI, 1.00-1.16), and for CVD (RR, 1.11; 95% CI, 1.05-1.16). <h3>Conclusions</h3> Some patients with ISH may be treated to a level that uncovers subclinical disease, and some may be overtreated. Further studies need to determine whether excessively low DBP can be prevented by more careful titration of antihypertensive therapy while maintaining SBP control. It is reassuring that patients receiving treatment for ISH never perform worse than patients receiving placebo in terms of CVD events.