Abstract 153: Heart Rate Volatility as a Predictor for Mortality Within 48 Hours After Surgical Procedure
Introduction: Heart Rate Volatility (HRVO) is a physiological measure of sympathetic activity defined by volatility of the heart rate (HR) over fixed time intervals.
Objectives: we sought to investigate the relationship between low HRVO (defined as SD<0.5 within a given time interval) during surgical procedures and higher mortality rates within 48 hours post-procedure.
Methods: We retrospectively reviewed all adult surgical procedures performed at our center from January 1, 2003 through July 1, 2013. Obstetrics, cardiothoracic, pediatric and liver transplant cases were excluded. Demographic, perioperative, hemodynamic, and mortality data were extracted from patients’ records. A propensity score matched case-control analysis was performed based on age, gender, ASA score, anesthesia type, Charlson index, ICD9 procedure code, emergency status, service year, use of beta blocker prior to procedure, HTN, diabetes and CHF. HRVO was calculated for each five minute interval of every case as the SD of all HR’s within that interval. Negative binomial regression was then used to model the count of intervals with HRVO<0.5 for the duration of the surgery.
Results: out of 242,387 surgical cases, our study included 283 patients that died within 48 hours after procedure, to whom we matched 566 subjects that did not die within 48 hours after procedure. In any time interval, the relative risk for having SD<0.5 for those who died within 48 hours was 1.53 (95% CI: 1.24-1.89; p=0.008), compared to control group.
Conclusion: Low HRVO during surgical procedure is associated with increased mortality risk within 48 hours after procedure. Strategies to identify HRVO early and modify it may lead to improvement in outcome.
Author Disclosures: Y. Mandel-Portnoy: None. M. Levin: None. S. Bansilal: None. G. Fischer: None. J. Halperin: None.
- © 2014 by American Heart Association, Inc.