Abstract 545: Incidence, Predictors And Risk Of 30-day Mortality Of Postoperative Acute Limb Ischemia Following Open-Heart Surgery

Abstract

Introduction: Postoperative acute limb ischemia (pALI) is a vascular emergency better prevented than treated. Knowledge of the predisposing factors is vital to prevention and early recognition. In this study, we examined the incidence, predictors, and the risk of 30-day mortality of pALI among patients who underwent open-heart surgery. Methods: We retrospectively analyzed data collected at a single university hospital as part of the Society of Thoracic Surgeons National Adult Cardiac Surgery database between January 2006 and January 2018. The primary outcome was pALI (coded in STS as CVaLbIsc) defined as any ischemic event of the arterial system of either upper or lower limbs. For this analysis transcatheter procedure and entries with the missing outcome variable were excluded. The final sample was divided into 2 groups based on the presence of pALI or not. Logistics regression models were used to assess for association between pALI and the preop variables. KM curves were plotted to compare survival probability between the 2 groups. Results: Among the 5231 records included in this analysis, there were 60 (1.15%) cases of pALI. Multivariate regression model adjusting for known risk factors of acute limb ischemia showed body surface area (OR 0.19 (95%CI 0.07 - 0.52), p= 0.001); emergent/urgent procedures (OR 2.57 (95%CI 1.32 - 4.98), p=0.005; history of PVD (OR 4.89 (95%CI 2.83 - 8.43), p=<.0001); preop IABP use (OR 4.16(95%CI 2.22 - 7.80), p=<.0001); preop IV steroid use (OR 3.07 (95%CI 1.32 - 7.16), p=0.009; history of infective endocarditis (OR 3.66 (95%CI 1.61 - 8.29), p=0.002; Cardiogenic shock (OR 2.86 (95%CI 1.41 - 5.78), p=0.003) are independent predictors of pALI. ROC curve AUC of the final model= 0.83. Conclusion: A knowledge of the above risk factors may help identify at-risk individuals that may benefit from perioperative limb tissue oxygenation or perfusion monitoring thereby facilitating prompt diagnosis and intervention.