A. Iyengar1, O. Kwon2, R. Shemin2, P. Benharash2 1University Of California – Los Angeles,David Geffen School Of Medicine,Los Angeles, CA, USA 2University Of California – Los Angeles,Division Of Cardiac Surgery,Los Angeles, CA, USA
Introduction: Cardiogenic shock following cardiac surgery is a rare complication that leads to increased morbidity and mortality. Intra-aortic balloon pumps (IABPs) may be used during the perioperative period to increase coronary perfusion and support cardiac output. The purpose of this study was to characterize predictors of postoperative cardiogenic shock in cardiac surgery patients, and examine differences between those with and without IABP support.
Methods: Retrospective analysis of UCLA’s Society of Thoracic Surgeon’s (STS) database was performed between January 2008 and July 2015. Preoperative demographic data for all patients were queried, and patient’s receiving IABP support during the perioperative period were identified. The Kruskal-Wallis and chi-squared tests were used for comparisons between IABP and control cohorts. Multivariable logistic regression with step-wise elimination was used to model postoperative cardiogenic shock in both the IABP and control cohorts.
Results: During the study period, 4,741 cardiac surgery patients were identified during the study period, of whom 268 (6%) received an IABP. IABP patients had higher rates of previous cardiac surgery (54% vs. 38%, p<0.001), congestive heart failure (69% vs. 43%, p<0.001), and preoperative cardiogenic shock (22% vs. 2%, p<0.001). Furthermore, IABP patients were more likely to have emergent operations (84% vs. 42%, p<0.001) and receive coronary artery bypass grafts (CABG, 63% vs. 32%). IABP patients had significantly greater ventilation times, ICU/total hospital stays, and 30-day mortality (all p<0.001), and more postoperative cardiogenic shock (10% vs. 3%, p<0.001).
Among the IABP cohort, preoperative dialysis, arrhythmias, and previous cardiac surgery were all associated with higher odds of postoperative cardiogenic shock (all p<0.10), while CABG operations were found to be protective compared to other cardiac operations (OR 0.33 vs 2.28, p=0.008 and 0.053, respectively). On multivariate analysis, previous cardiac surgery and preoperative arrhythmia remained significant (AOR 5.95, p=0.005, and 2.94, p=0.015, respectively)predictors of postoperative cardiogenic shock. In the control cohort, several factors including hypertension, chronic lung disease, preoperative congestive heart failure, cardiogenic shock, inotropic medications, urgent/emergent status, non-CABG/Valve cardiac surgery, and prolonged bypass times, were associated with postoperative cadiogenic shock.
Conclusion: Factors associated with cardiogenic shock among post-cardiac surgery patients differ between those patients receiving IABP and those who do not. Among IABP patients, previous cardiac surgery and arrhythmias were associated with increased rates of cardiogenic shock, while shock was multifactorial among control patients. The etiology of cardiogenic shock may differ between these two cohorts, and early identification of those patients at risk may lead to improved outcomes.