Systolic blood pressure and cardiovascular outcomes during treatment of hypertension
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.