Effect of Heart Rate on Poor Outcome in Stroke Patients Treated with Intra-arterial Thrombectomy

Background and Purpose— The relationship between heart rate and the prognosis of patients with large vessel occlusion strokes treated with mechanical thrombectomy (MT) is not well established. This study aimed to evaluate the association of mean heart rate and heart rate variability with the clinical outcomes after MT therapy. Methods— Acute ischemic stroke patients undergoing MT therapy were prospectively recruited from March 2020 to November 2022. Their heart rate was continuously collected hourly within the initial 72 hours after MT procedure, and the variability of heart rate was measured by standard deviation(SD) and coefficient of variation (CV). All-cause mortality and worsening of functional outcome (a shift of entire range of modified Rankin Scale (mRS) score) at 3-month were captured. Results— Among 191 MT-treated patients, 51(26.7%) patients died at 3-month after stroke. Increased mean heart rate per 10-bpm, heart rate SD and CV per 5-unit were all associated with the increased risk of mortality (adjusted hazard ratio [aHR] with 95% CI: 1.29 [1.09-1.51], 1.19 [1.07-1.32], 1.14 [1.03-1.27]; respectively). Patients in the highest tertile of heart rate SD was associated with the increased risk of mortality (4.62, 1.70-12.52). Furthermore, increased mean heart rate per 10-bpm, heart rate SD and CV per 5-unit were associated with the worsening of functional outcome (adjusted odds ratio [aOR] with 95% CI: 1.35 [1.11-1.64], 1.27 [1.05-1.53], 1.19 [1.02-1.40]; respectively). A linear relationship was observed between mean heart rate or heart rate SD and mortality; while all of the heart rate measures in this study showed a linear relationship with the worsening of functional outcome. Conclusions— Higher mean heart rate and HRV were associated with the increased risk of 3-month all-cause mortality and worse functional outcome after MT therapy for AIS patients.