Impact of resting heart rate on mortality, disability and cognitive decline in patients after ischaemic stroke.

Abstract

Recurrent stroke is a frequent and disabling event. A high heart rate is associated with cardiovascular outcomes. We investigated the effects of the resting heart rate on cardiovascular and neurological outcomes after recurrent stroke in the high-risk population of the PRoFESS study. A total of 20,165 patients after ischaemic stroke (mean age 66.1, SD 8.6 years) assigned to the treatment arms of the PRoFESS trial were pooled divided by quintiles of the baseline heart rate and analysed according to cardiovascular and functional outcomes after stroke: recurrent stroke and major cardiovascular outcomes such as stroke, myocardial infarction, and worsening or new-onset heart failure as well as death from cardiovascular and non-cardiovascular causes. Pre-defined endpoints were disability after a recurrent stroke, assessed with the modified Rankin scale (mRS) and the Barthel index at 3 months, and cognitive function, assessed with the Mini-Mental State Examination (MMSE) score at 4 weeks after randomization and at the penultimate visit. Patients in the two highest quintiles of heart rate (77-82 and >82 b.p.m.) were at a higher risk for total death [hazard ratio (HR) 1.42, 95% CI 1.19-1.69 and HR 1.74, 95% CI 1.48-2.06, P < 0.0001] compared with the lowest quintile. Similar results were observed for vascular death [71-≤76 b.p.m., HR 1.39 (1.11-1.74), P < 0.0001] and non-vascular death [from >82 b.p.m., HR 1.66 (1.29-2.13), P = 0.0016]. Myocardial infarction (P = 0.7084) and recurrent stroke (P = 0.1379) were not significantly associated with the baseline heart rate. Hazard ratios were adjusted to multiple confounders including the baseline blood pressure. In the group of patients with a recurrent stroke, an association of a lower heart rate to better outcomes was measured with the Barthel index across all heart rate groups. In addition, there was a significant association of the baseline heart rate to the occurrence of significant cognitive decline according to an MMSE score ≤24 points at 1 month and at the penultimate visit or a decline of ≥2 points between these two time periods. Better independence score at a low heart rate were observed. The heart rate is a risk indicator for mortality in patients with stroke and, importantly, a low heart rate is associated with a better functional outcome and less cognitive decline after an ischaemic stroke. ClinicalTrials.gov, number NTC00153062.