Background: The association between systolic blood pressure and all-cause mortality differs between frail and nonfrail individuals, highlighting uncertainties about the effectiveness of antihypertensive treatments in frail populations.
Methods: Using data from the SHEP trial (Systolic Hypertension in the Elderly Program), a baseline frailty index (FI), including 55 variables, was constructed. Fine-Gray subdistribution hazard models and Cox proportional hazards regression models were used to explore the association between baseline FI and the risks of stroke, cardiovascular disease, and all-cause death, as well as to examine whether the impact of antihypertensive treatment on these outcomes was modified by baseline FI.
Results: A total of 4692 participants (mean age, 72.1 years; 56.7% women) were included, with a mean (SD) FI of 0.134 (0.061). During a median follow-up period of 4.4 years, FI was associated with a higher risk of stroke (subdistribution hazard ratio, 1.24 [95% CI, 1.10-1.39]; per SD higher FI), cardiovascular disease (subdistribution hazard ratio, 1.18 [95% CI, 1.09-1.26]), and all-cause death (hazard ratio, 1.37 [95% CI, 1.26-1.50]), after adjustment for age, sex, race, and treatment group. Although those with higher levels of frailty were at higher risk for all outcomes, there was no evidence of an interaction between baseline FI and antihypertensive treatment (P for interaction >0.05 for all outcomes).
Conclusions: In individuals with isolated systolic hypertension, antihypertensive treatment improved associated outcomes even among those with a higher degree of frailty. These findings from the SHEP trial reinforce evidence from other seminal antihypertensive trials, which collectively inform the appropriate treatment of frail individuals with hypertension.
Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00000514.
Keywords: aged; antihypertensive agents; cardiovascular diseases; frail elderly; frailty.