Jae SY, Heffernan K, Kurl S, et al. - In this prospective study, experts aspired to explore whether the chronotropic response to exercise, defined as the percentage of chronotropic index ([maximum heart rate − resting heart rate] / [220 − age − resting heart rate] × 100), is correlated with an increased risk of stroke in a general population. This investigation was based on a population sample of 2,036 men aged 42-60 years in the Kuopio Ischemic Heart Disease cohort study. Three hundred forty-three incident stroke (289 ischemic and 66 hemorrhagic) events occurred during a median 27-year follow-up. There was an increased risk of stroke and ischemic stroke, but not hemorrhagic stroke, compared with the bottom vs top quintile of the chronotropic reserve in analyses that adjusted for potential risk factors. Such results indicate that an impaired chronotropic response to exercise is independently linked to a higher risk of total and ischemic stroke events in middle-aged men. The role of chronotropic incompetence as a potential prognostic indicator for stroke risk during exercise testing requires further investigation.