Intensive BP control modestly decreased the likelihood of a broad composite of CV events, but with methodologic limitations

Reference

Zhang W, Zhang S, Deng Y, et al, for the STEP Study Group. Trial of intensive blood-pressure control in older patients with hypertension. N Engl J Med 2021;385(14):1268-1279.

Synopsis

These Chinese researchers recruited patients aged 60 to 80 years with systolic blood pressure between 140 mm Hg and 190 mm Hg or with treated hypertension. Blood pressure was measured with 3 serial measurements 1 minute apart after the patient had been sitting quietly for 5 minutes. Patients were randomized in an open-label fashion to either a systolic blood pressure target of 110 to 129 mm Hg or a target of 130 to 149 mm Hg. Groups were comparable at baseline, with a mean age of 66 years, 46% men, and 65% with a 10-year risk of cardiovascular events of at least 15% based on the Framingham Risk Score. Participants were given a blood pressure monitor and were required to use it at least once per week; readings were transmitted to the study center. The authors initially planned to do a cluster-randomized trial of an app-assisted management program, but they ultimately scrapped that idea and gave the app to everyone. A standard treatment algorithm using olmesartan, amlodipine, and hydrochlorothiazide was used to achieve blood pressure targets. The primary outcome was a very broad composite of stroke, acute myocardial infarction, acute coronary syndrome, acute decompensated heart failure, coronary revascularization, atrial fibrillation, or cardiovascular death. A total of 8511 patients were randomized and followed up for a median of 3.3 years. The intensive treatment group had a mean blood pressure of approximately 127 mm Hg throughout the trial; the usual care group had a mean blood pressure of approximately 135 mm Hg. The study was stopped early when an interim analysis identified a reduction in the primary composite outcome in the intensive treatment group (3.5% vs 4.6%; P = .007; number needed to treat [NNT] = 91 for 3.3 years). With regard to individual outcomes, there was a significant reduction in the likelihood of stroke (1.1% vs 1.7%; hazard ratio [HR] 0.67; 95% CI 0.47 - 0.97), acute coronary syndrome (1.3% vs 1.9%; HR 0.67; 0.47 - 0.94), and acute decompensated heart failure (0.1% vs 0.3%; HR 0.27; 0.08 - 0.98). Although the authors don't report P values for individual outcomes to avoid being accused of failing to adjust for multiple comparisons, they do present the confidence intervals. Notably, there was no difference in all-cause mortality between groups (1.6% for intensive therapy vs 1.5% for usual care). I have serious concerns about the adequacy of their adverse event reporting. The similarly sized SPRINT trial reported far more episodes of syncope (276 vs 8 in the current trial) and acute kidney injury (324 vs 118), and the current study does not report electrolyte abnormalities.