A nonlinear association between resting heart rate and ischemic stroke among community elderly hypertensive patients

Background: Ischemic stroke is a major public health problem and a main cause of death in China. However, how resting heart rate may associate with ischemic stroke among patients with hypertension remains unclear.Objective: To investigate the association between resting heart rate and ischemic stroke among elderlies with hypertension in China.Methods: We conducted a retrospective study of elderlies with hypertension who aged ≥60 years and were free from a stroke at baseline. Resting heart rate at baseline was treated as both continuous and categorical variable. Hazard ratios for ischemic stroke were estimated by multivariate Cox proportional hazards models.Results: A total of 3071 elderlies with hypertension [1369 (44.6%) men, an average age of 71.3 ± 7.1 years] were enrolled, and 182 cases of ischemic stroke occurred during a mean follow-up period of 5.5 years. Multivariate Cox regression showed that every 10 bpm increment in resting heart rate elevated the risk of ischemic stroke by 21% (95%CI: 1.05, 1.73; P = 0.018). After adjusting for confounders, resting heart rate ≥90 bpm significantly associated with the risk of ischemic stroke (HR: 1.35, 95% CI = 1.16, 2.78) when using the resting heart rate <60 bpm as a referent. Subgroup analysis showed that the relation between resting heart rate and risk of ischemic stroke was seem to be stronger in female (HR: 1.32 vs 1.11), those with uncontrolled hypertension (HR: 1.32 vs 1.12), people with combined diabetes and hypertension (HR: 1.31 vs 1.12), people with overweight (HR: 1.39 vs 1.02) and those who aged >75 (HR: 1.33 vs 1.11). Smoothing spline plots suggested the optimal resting heart rate for the lowest risk of ischemic stroke was between 60 and 80 bpm.Conclusions: In Chinese elderly hypertensive patients, elevated resting heart rate was an independent predictor of ischemic stroke, and the optimal resting heart rate was around 70 bpm.