Systolic Blood Pressure and Cardiovascular Outcomes During Treatment of Hypertension

Abstract

Objective

Randomized controlled trials in hypertension demonstrate cardiovascular benefits when systolic blood pressures are reduced from higher values to<160 mm Hg. The value of lower targets has not been fully defined, although major guidelines recommend achieving systolic blood pressures of<140 mm Hg. This study was conducted to explore cardiovascular outcomes at differing on-treatment blood pressure levels.

Methods

On the basis of a prespecified plan to explore relationships between clinical outcomes and systolic blood pressures, the pooled cohort of high-risk hypertensive patients (N=10,705) in the Avoiding Cardiovascular Events through Combination Therapy in Patients Living with Systolic Hypertension trial were divided into 4 strata of systolic blood pressure levels: >140 mm Hg, 130 to <140 mm Hg, 120 to <130 mm Hg, and 110 to <120 mm Hg. The primary end point was cardiovascular death or nonfatal myocardial infarction or stroke. Outcomes comparisons between the blood pressure groups were by Cox regression.

Results

The mean patient age was 68 years, and the study duration was 35.7 months. The primary end point occurred in 171 of 3429 patients (5.0%) with systolic blood pressure in the 10 mm Hg range<140 and in 179 of 2354 patients (7.6%) with systolic blood pressure≥140 mm Hg (hazard ratio [HR], 0.62; 95% CI, 0.50-0.77; P=.0001). Likewise, cardiovascular death decreased by 36% (P=.0147), total myocardial infarction (fatal+nonfatal) decreased by 37% (P=.0028), and stroke decreased by 47% (P=.0002). Cardiovascular event rates in those with systolic blood pressure<130 mm Hg were not different from those with systolic blood pressure<140 mm Hg. However, compared with systolic blood pressure<130 mm Hg, stroke incidence in those with systolic blood pressure<120 mm Hg was lower (HR, 0.60; 95% CI, 0.35-1.01; P=.0529), but myocardial function was higher (HR, 1.52; 95% CI, 1.00-2.29; P=.0437), as were composite coronary events (myocardial infarction, hospitalized angina, or sudden death) (HR, 1.63; 95% CI, 1.18-2.24; P=.0023). The renal end point of a sustained>50% increase in serum creatinine was significantly lower in those with systolic blood pressure<140 mm Hg than in any of the other higher or lower blood pressure ranges.

Conclusions

In high-risk hypertensive patients, major cardiovascular events are significantly lower in those with systolic blood pressures<140 mm Hg and<130 mm Hg than in those with levels>140 mm Hg. There are stroke benefits at levels<120 mm Hg, but they are offset by increased coronary events. Renal function is best protected in the 130 to 139 mm Hg range.

Source: www.amjmed.com