Influence of Baseline Smoking Status on Intensive Blood Pressure Control: Results From the STEP Randomized Trial

The Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) trial has proven that intensive systolic blood pressure (SBP) lowering reduces cardiovascular events. However, the cardiovascular risks posed by smoking have caused uncertainty regarding the effects of intensive SBP control in smokers.

In this secondary subgroup analysis of the STEP trial, the participants were categorized into nonsmokers and current smokers on the basis of their baseline smoking status. The primary outcome was a composite of cardiovascular outcomes, including stroke, acute coronary syndrome, acute decompensated heart failure, coronary revascularization, atrial fibrillation, and death from cardiovascular causes. Cox proportional hazards regression and interaction analysis were used to assess the effects of baseline smoking status on intensive SBP control.

A total of 8489 patients were included in this analysis. The proportion of patients who reached the intensive SBP target was smaller in current smokers during the first 9 months. Compared with nonsmokers, current smokers had a higher adjusted risk of primary outcome (hazard ratio, 1.39; 95% confidence interval, 1.03-1.88; P = 0.03) and stroke (hazard ratio, 1.66; 95% confidence interval, 1.03-2.67; P = 0.04). The interactions between baseline smoking status and SBP treatment were not statistically significant for all outcomes. Findings were similar in sensitivity analyses using 4 smoking categories and in analyses including only never and often smokers.

Smoking was associated with a higher risk of primary outcome and stroke. We observed no statistical evidence of heterogeneity in the treatment effect of intensive SBP control according to smoking status.

NCT03015311.