Objective: to evaluate whether postoperative heart rate variability (HRV) predicts short-term outcomes in patients undergoing coil embolization of ruptured aneurysms.
Methods: Consecutive patients receiving endovascular coiling to treat aneurysmal subarachnoid hemorrhage (SAH) were retrospectively reviewed between November 2011 and December 2014 in the authors' institution. Heart rate (HR) and blood pressure (BP) recorded in the initial 24 h after endovascular treatment were extracted along with other clinical data. HR variability (HRV) and BP variability (BPV) were determined as standard deviation (SD) and successive variation (SV) of every 2-h HR and BP. The correlation between HRV and clinical outcomes as assessed by Glasgow Outcome Scale (GOS) scores at discharge were analyzed statistically.
Results: Compared to the 310 patients with favorable outcomes (GOS 4-5), the 35 with unfavorable outcomes (GOS 1-3) had significantly higher HR, HRV, and BPV in the first postoperative day. Furthermore, HRV-SD remained to be an independent predictor of unfavorable recovery in multivariate logistic analysis (OR = 1.14; 95% CI, 1.02-1.29; P = 0.026) after adjusting for age, postoperative fever, and Glasgow Coma Scale scores on admission, which have been identified as predictors of poor prognosis. The area under the receiver operating characteristic curves for HRV-SD and BPV-SV were found to be 0.745 (95% CI, 0.658-0.833) and 0.633 (95% CI, 0.524-0.741), respectively (P < 0.05).
Conclusions: Higher HRV in the first day after coil embolization was associated with unfavorable outcomes in patients with SAH. Early detection and appropriate treatment of the overactive sympathetic activity might promote functional recovery after SAH. Abbreviation: BP: Blood pressure; CI: Confidence interval; DBP: Diastolic blood pressure; GCS: Glasgow coma scale; GOS: Glasgow outcome scale; HR: Heart rate; HRV: Heart rate variability; OR: Odds ratio; ROC: Receiver operating characteristics; SD: Standard deviation; SAH: Subarachnoid hemorrhage; SV: Successive variation; SBP: Systolic blood pressure.
Keywords: Heart rate variability; blood pressure variability; prognosis; subarachnoid hemorrhage.