Effect of renal function status on the prognostic value of heart rate in acute ischemic stroke patients.

BACKGROUND AND AIMS: The association between heart rate and prognosis of ischemic stroke remains debatable, and whether renal function status influences the relationship between them is still not elucidated. METHODS: A total of 3923 ischemic stroke patients were included in this prospective multicenter study from the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS). The primary outcome was a combination of death and major disability (modified Rankin Scale score ≥3) at 3 months after stroke. Secondary outcomes were, separately, death and major disability. RESULTS: The association between heart rate tertiles and primary outcome was appreciably modified by renal function status (pinteraction = 0.037). After multivariate adjustment, high heart rate was associated with increased risk of primary outcome in patients with abnormal renal function (odds ratio, 1.61; 95% confidence interval, 1.02-2.54; ptrend = 0.039) but not in patients with normal renal function (odds ratio, 0.96; 95% confidence interval, 0.75-1.23; ptrend = 0.741), when two extreme tertiles were compared. Each 10 bpm increase of heart rate was associated with 21% (95% CI: 1%-44%) increased risk of primary outcome, and a linear association between heart rate and risk of primary outcome was observed among patients with abnormal renal function (p for linearity = 0.002). CONCLUSIONS: High heart rate may be merely a strong predictor of poor prognosis in acute ischemic stroke patients with abnormal renal function, suggesting that heart rate reduction should be applied to ischemic stroke patients with abnormal renal function to improve their prognosis.