Heart rate entropy is associated with mortality after intracereberal hemorrhage

Abstract

Background: Autonomic nervous system changes have been associated with outcome after intracerebral hemorrhage (ICH) previously. We aimed to investigate the association of heart rate entropy (HRE) with mortality after ICH.

Methods: Sample HRE, heart rate variability and baroreflex sensitivity were examined in consecutive ICH patients. Hematoma volume, intraventricular hemorrhage, infratentorial origin, consciousness impairment and age were combined into standard ICH score.

Results: In 47 patients suffering ICH (mean age 61 years, median hemorrhage volume 38 mL) the areas under the curve (AUC) for mortality were 0.86, 0.83, 0.76, 0.74, 0.72 and 0.7 for HRE, ICH-score, normalized low frequency powers, low frequency/high frequency powers ratio, normalized high frequency powers and BRS, respectively. HRE and ICH score were associated with mortality independently (adjusted odd ratio (aOR) 0.09, 95% confidence interval (CI) 0.1-0.8, p = .03 and aOR 2.6, CI 1.03-6.6, p = .04). Combining ICH score with HRE into a novel score resulted in an AUC of 0.94, CI 0.88-0.99, p < .001.

Conclusion: Compared to several autonomic markers HRE seems to bear the largest amount of information on death probability after ICH. Moreover, HRE may predict mortality comparable to ICH score. Combining HRE with ICH score may increase the predictive performance for mortality after ICH.

Keywords: Autonomic; Heart rate entropy; Intracerebral hemorrhage; Mortality; Outcome.