Initial in-hospital heart rate is associated with three-month functional outcomes after acute ischemic stroke

BACKGROUND: Increased heart rate (HR) has been associated with stroke risk and outcomes. MATERIAL AND METHODS: We analyzed 1,420 patients from a hospital-based stroke registry with acute ischemic stroke (AIS). Mean initial in-hospital HR and the coefficient of variation of HR (HR-CV) were derived from the values recorded during the first 3 days of hospitalization. The study outcome was the 3-month functional outcome. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using multivariable logistic regression analysis. RESULTS: A higher mean HR level was significantly and continuously associated with a higher probability of unfavorable functional outcomes. Compared with the reference group (mean HR < 70 beats per minute), the multivariate-adjusted OR for an unfavorable outcome was 1.81 (95% CI, 1.25–2.61) for a mean HR ≥ 70 and < 80 beats per minute, 2.52 (95% CI, 1.66 − 3.52) for a mean HR ≥ 80 and < 90 beats per minute, and 3.88 (95% CI, 2.20–6.85) for mean HR ≥ 90 beats per minute. For stroke patients with a history of hypertension, the multivariate-adjusted OR for patients with a HR-CV ≥ 0.12 (versus patients with a HR-CV < 0.08 as a reference) was 1.73 (95% CI, 1.11–2.70) for an unfavorable outcome. CONCLUSIONS: Our results indicated that a high initial in-hospital HR was significantly associated with unfavorable 3-month functional outcomes in patients with AIS. In addition, stroke patients with a HR-CV ≥ 0.12 also had unfavorable outcomes compared with those with a HR-CV < 0.08 if they had a history of hypertension. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12883-021-02252-2.