Backgrounds: Previous studies demonstrated the association of resting heart rate with cardiovascular outcomes while there were only few evidence for patients who experienced ischemic stroke. As atrial fibrillation (AF) is characterized by rapidity and irregularity of heart rate, heart rate characteristics might be a predictor for future vascular event in patients with AF acute ischemic stroke.
Methods: From a multicenter prospective registry of stroke patients, acute ischemic stroke patients with AF who admitted within 48 hours after stroke onset were included. Heart rate data during the first 24 hours after admission were collected and level and variability of heart rate were assessed by mean and coefficient of variation (CV). Primary outcome was a composite of stroke recurrence, myocardial infarction and all-cause death, which was prospectively captured until 1 year after stroke onset.
Results: A total of 2,046 patients were included for the final analysis. There were 102 (5.0%) stroke recurrence, 9 (0.4%) myocardial infarction and 440 (21.5%) death events within 1 year after stroke onset. Proportional hazards regression models were constructed and the non-linearity of effects of heart rate parameters were examined for outcome events. Among all the associations, effects of mean heart rate on primary outcome and all-cause mortality were non-linear (p’s for quadratic effect = 0.017 and 0.032, respectively). The overall effects were significant only for effects of mean heart rate on primary outcome and all-cause mortality (P =0.013 and P=0.006, respectively). Effects of CV on outcome variables were not significant.
Conclusion: This study suggests that mean heart rate during the first day of hospitalization was a predictor of future vascular events in AF patients presenting with acute ischemic stroke and the association seems to be non-linear ‘J shaped’. However, heart rate variability did not affect.