Association of systolic blood pressure levels with cardiovascular events and all-cause mortality among older adults taking antihypertensive medication.

Introduction: The aim of the study was to identify the association of systolic blood pressure (SBP) levels with cardiovascular events, all-cause mortality, and falls among elderly persons taking antihypertensive medication.

Methods: US adults ≥ 45 years of age taking antihypertensive medication enrolled in the REGARDS study were categorized into 3 age groups: 55-64, 65-74 and ≥ 75 years old and baseline on-treatment SBP levels. Our primary analyses focused on incident cardiovascular disease (CVD) (n=9787) and all-cause mortality (n=13,948).

Results: During follow-up, 530 (5.4%) participants had CVD events and 2095 (15%) participants died. After multivariable adjustment among participants ≥ 75, the incidence of CVD per 1000 person-years (95% confidence interval) was 16.9 (11.1-25.7), 13.4 (9.2-19.7), 11.6 (7.6-17.7), 17.8 (11.2-27.5) and 36.7 (26.6-50.8) at SBP levels of <120, 120-129, 130-139, 140-149, and ≥ 150 mmHg, respectively. For the same SBP categories, the adjusted CVD incidence rates were 9.3 (7.2-12.0), 10.0 (8.1-12.3), 9.4 (7.5-11.8), 14.0 (11.0-17.8), and 16.4 (12.5-21.4), respectively, among participants 55-64 years, and 16.5 (13.6-21.5), 17.4 (14.8-20.6), 19.2 (16.4-22.5), 22.3 (18.6-26.9), and 27.6 (22.7-33.4), respectively, for participants 65-74 years. Among participants aged 55-64 and 65-74 years, a linear association was present between higher SBP categories and all-cause mortality risk (each p-trend<0.001). In contrast, for participants ≥ 75 years no association was present between SBP and all-cause mortality (p-trend=0.319). No association was observed between SBP and falls among participants in all age groups.

Conclusions: Among adults aged ≥ 55 taking antihypertensive medication, SBP between 120 and 139 mmHg was significantly associated with a reduced risk for cardiovascular and all-cause mortality outcomes.