Time to benefit for stroke reduction after blood pressure treatment in older adults: A meta-analysis

Abstract

Background: Hypertension treatment in older adults can decrease mortality, cardiovascular events, including heart failure, cognitive impairment, and stroke risk, but may also lead to harms such as syncope and falls. Guidelines recommend targeting preventive interventions with immediate harms and delayed benefits to patients whose life expectancy exceeds the intervention's time to benefit (TTB). Our objective was to estimate a meta-analyzed TTB for stroke prevention after initiation of more intensive hypertension treatment in adults aged ≥65 years.

Methods: Studies were identified from two Cochrane systematic reviews and a search of MEDLINE and Google Scholar for subsequent publications until August 31, 2021. We abstracted data from randomized controlled trials comparing standard (untreated, placebo, or less intensive treatment) to more intensive treatment groups in older adults (mean age ≥ 65 years). We fit Weibull survival curves and used a random-effects model to estimate the pooled annual absolute risk reduction (ARR) between control and intervention groups. We applied Markov chain Monte Carlo methods to determine the time to ARR thresholds (0.002, 0.005, and 0.01) for a first stroke.

Results: Nine trials (n = 38,779) were identified. The mean age ranged from 66 to 84 years and study follow-up times ranged from 2.0 to 5.8 years. We determined that 1.7 (95%CI: 1.0-2.9) years were required to prevent 1 stroke for 200 persons (ARR = 0.005) receiving more intensive hypertensive treatment. Heterogeneity was found across studies, with those focusing on tighter systolic blood pressure control (SBP < 150 mmHg) showing longer TTB. For example, in the SPRINT study (baseline SBP = 140 mmHg, achieved SBP = 121 mmHg), the TTB to avoid 1 stroke for 200 patients treated was 5.9 years (95%CI: 2.2-13.0).

Conclusions: More intensive hypertension treatment in 200 older adults prevents 1 stroke after 1.7 years. Given the heterogeneity across studies, the TTB estimates from individual studies may be more relevant for clinical decision-making than our summary estimate.

Keywords: hypertension; stroke; time to benefit.

FIGURE 1

Study identification and selection

FIGURE 2

Meta‐analyzed absolute risk reduction over time with more intensive blood pressure treatment. The dark blue line signifies the difference in number of stroke events between standard and more intensive blood pressure treatment groups. The light blue areas above and below the line indicate the upper and lower 95% confidence limits of the ARR, respectively

FIGURE 3

Forest plots for time to benefit to achieve ARR thresholds. (A) Forest plot for ARR = 0.002. (B) Forest plot for ARR = 0.005. (C) Forest plot for ARR = 0.01