Low diastolic blood pressure is not related to risk of first episode of stroke in a high-risk population: A secondary analysis of SPRINT

Abstract

Background—Hypertension is the most prevalent and leading risk factor for stroke. SPRINT (The Systolic Blood Pressure Intervention Trial) assessed the effects on cardiovascular event risk of intensive compared with standard systolic blood pressure reduction. In this secondary analysis of SPRINT data, we investigated how low on-treatment diastolic blood pressure (DBP) influenced risk for stroke events. Methods and Results—For this analysis, we used SPRINT_POP (Primary Outcome Paper) ResearchMaterials from the National Heart, Lung and Blood Institute (NHLBI) Biologic Specimen and Data Repository Information Coordinating Center. Data for 8944 SPRINT participants were analyzed from the period after target blood pressure was achieved until the end of the trial. Overall, there were 110 stroke events, including 49 from the intensive-treatment arm and 61 in the standard-treatment group. In participants with DBP <70 mm Hg, stroke risk was higher than with DBP ≥70 mm Hg (hazard ratio, 1.467; 95% CI 1.009–2.133; P=0.0445). Univariable Cox proportional hazard risk analysis showed that in the whole group, age and cardiovascular and chronic renal diseases were stroke risk factors. These risk factors were related to lower DBP and higher pulse pressure, however, not to study arm.Multivariable Cox proportional hazard analysis revealed that only age, history of cardiovascular disease, current smoking status and on-treatment systolic blood pressure were significantly related to stroke risk. Conclusions—Low on-treatment DBP is not related to the risk for the first stroke, in contrast to older age, the history of cardiovascular disease, current smoking status, and on-treatment systolic blood pressure.