Independent Predictors of Perioperative Stroke-Related Mortality after Cardiac Surgery

Abstract

Background and purpose: Perioperative stroke remains a devastating complication after cardiac surgery and is associated with significant morbidity and mortality. Despite the significant contribution of stroke to perioperative mortality, risk factors for perioperative stroke-related mortality have not been well characterized. Our aim was to identify independent predictors of perioperative stroke-related mortality after cardiac surgery, using the Pennsylvania Health Care Cost Containment Council (PHC4) database which provides information on cause of death.

Methods: We retrospectively examined patient medical records from 2012 to 2014 of 3345 patients (ages 18-99) who underwent a cardiac surgical procedure and suffered perioperative (30-day) mortality. Perioperative stroke-related mortality was identified by International Classification of Diseases, Tenth Revision, Clinical Modification cause of death codes. We performed Fisher's exact test and multivariate analysis to identify comorbidities that independently predict perioperative stroke-related mortality.

Results: After controlling for all variables with multivariate analysis, we found that patients with carotid stenosis were 4.9 (adjusted odds ratio [aOR], 95% confidence interval [CI] 1.8-12.8) times more likely to die from a stroke than from other causes, when compared to patients without carotid stenosis. Other independent predictors of perioperative stroke-related mortality included in-hospital stroke (aOR 108.8, 95%CI 48.2-245.9), history of stroke (aOR 17.1, 95%CI 3.3-88.4), and age ≥ 80 (aOR 4.9, 95%CI 2.1-11.2).

Conclusions: This is the first study to establish carotid stenosis, among other comorbidities, as an independent predictor of perioperative stroke-related mortality after cardiac surgery. Understanding risk factors for mortality from stroke will help enhance the efficacy of preoperative screening, intraoperative neurophysiological monitoring, and potential treatments for stroke. Interventions to manage carotid stenosis and other identified risk factors prior to, during, or immediately after surgery may have the potential to reduce perioperative stroke-related mortality after cardiac surgery.

Keywords: Perioperative mortality; atrial fibrillation; cardiac surgical procedure; carotid stenosis; perioperative stroke.