Intensive Blood Pressure Control in Older Patients With Hypertension: 6-Year Results of the STEP Trial

Abstract

Background: The STEP (Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients) trial showed that intensive systolic blood pressure (SBP) control reduced cardiovascular risk.

Objectives: Study investigators conducted an extended follow-up of the STEP trial to determine the longer-term effects of intensive blood pressure (BP) control.

Methods: In this randomized controlled trial, 8,511 patients with hypertension were randomly assigned to the intensive treatment group, with an SBP target of 110 mm Hg to <130 mm Hg, or the standard treatment group, with an SBP target of 130 mm Hg to <150 mm Hg. After the original trial ended, all surviving patients, either in the standard group or the intensive treatment group previously, received intensive treatment in the extended period, referred to as the delayed intensive treatment group or the sustained intensive treatment group. The primary outcome was a composite of stroke, acute coronary syndrome, acute decompensated heart failure, coronary revascularization, atrial fibrillation, or death resulting from cardiovascular causes. The Fine-Gray subdistribution hazard model was used to estimate the HR between the 2 groups, and g-formula methods were initiated to compare overall primary outcome risks with intensive treatment initiated from randomization and initiated every year after randomization.

Results: After a median follow-up of 6.11 years, the mean SBP was 127.9 mm Hg in the sustained intensive treatment group and 129.5 mm Hg in the delayed intensive treatment group. The incidence rate of primary outcome was 1.12% per year in the sustained intensive treatment group, compared with 1.33% per year in the delayed intensive treatment group (HR: 0.82; 95% CI: 0.71-0.96). No difference in safety event rates between the 2 groups was observed except for hypotension, which occurred more frequently in the sustained intensive treatment group. Furthermore, analyses using the parametric g-formula showed that compared with the standard BP treatment, intensive treatment initiating from randomization (0 month) yielded the greatest benefit (relative risk [RR]: 0.83; 95% CI: 0.70-0.96), with an attenuated cardiovascular benefit for later initiation from 12 months (RR: 0.88; 95% CI: 0.76-0.99).

Conclusions: Our results suggested that sustained intensive BP control could benefit patients with hypertension compared with delayed intensive treatment in the longer-term follow-up. The earlier intensive treatment is initiated after the hypertension diagnosis, the greater the cardiovascular benefits will be. (Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients [STEP]; NCT03015311).

Keywords: cardiovascular outcomes; hypertension; intensive blood pressure control.