Benefit and Harm of Intensive Blood Pressure Control by Cardiovascular Risk.

Abstract

BACKGROUND Current guidelines for blood pressure treatment are stratified by cardiovascular disease (CVD) risk levels. However, the impact of CVD risk on the benefits and harms of intensive blood pressure control remains unknown. This study aims to evaluate the cardiovascular benefits and treatment-related adverse events associated with intensive blood pressure control across different CVD risk levels. METHODS From the STEP trial (Strategy of Blood Pressure Intervention in Older Hypertensive Patients), 8262 patients were stratified by tertiles of baseline 10-year CVD risk. Benefit and harm were determined as a reduction of primary outcomes and an increase of adverse events, respectively. Cox proportional hazard models were used to examine the association between CVD risk and outcome events in each tertile. The Poisson regression model was used to predict the benefits and harms. RESULTS During a median follow-up of 3.32 years, 333 primary outcomes and 611 adverse events occurred. Within each risk tertile, there were lower rates of the primary outcome in the intensive treatment group (overall hazard ratio, 0.76 [95% CI, 0.61-0.94]), and the hazard ratio for adverse events was 1.1 (95% CI, 0.94-1.28). Patients with higher CVD risk had higher absolute risk reduction of the primary outcome and absolute risk increase of adverse events. The predicted benefit-to-harm ratio differed significantly across each CVD risk tertile but favored intensive control overall. CONCLUSIONS Higher CVD risk was associated with increased benefit and harm from intensive blood pressure control. Although benefit and harm profiles varied across CVD risk levels, the overall benefit was greater than harm in all risk tertiles.