Predictors of Perioperative Outcomes in Chronic Limb-threatening Ischemia Patients

Background: Revascularization in chronic limb-threatening ischemia (CLTI) patients carries a risk of perioperative events. Scoring systems such as the Society for Vascular Surgery vascular quality initiative mortality prediction score (VQI MPS) for 30 days and 2-year mortality and revised cardiac risk index (RCRI) for perioperative major adverse cardiac events (MACE) have been validated to risk stratify patients. Both scoring systems had not been previously validated in an Indian cohort. Aims and Objectives: This study was conducted to validate both scoring systems and to identify predictors of perioperative adverse events. The primary objective was the validation of scoring systems based on observed peri-operative 30-day mortality and MACE. The secondary objective was to identify risk factors that affected these outcomes. Materials and Methods: Data of subsequent CLTI patients who underwent open or endovascular revascularization in a single centre between 2018 and 2024 were retrieved from a prospectively maintained database and retrospectively analysed. Patients who were lost to follow-up or had incomplete data were excluded from the study. MACE was defined as any acute coronary syndrome, pulmonary oedema, or cardiac-related death. Validity of VQI MPS and RCRI was calculated using receiver-operating curves. Predictors of outcome were analysed by univariate analysis and logistic regression. Results: One hundred forty-six patients were analysed and risk-stratified based on VQI MPS and RCRI. The mean age was 68 ± 9 years with 31.5% females. About 88.4% ( n = 129/146), 9.6% ( n = 14/146), and 2% ( n = 3/146) were categorized into low, medium, and high risk as per VQI MPS and 19 (13.05%), 59 (40.4%), 49 (33.5%), and 19 (13.05%) patients were categorized into Class 1, II, III, IV and above according to RCRI, respectively. Both scoring systems accurately risk-stratified procedures into different strata. Seven (4.79%) patients died within 30 day of procedure and 10 (6.84%) patients had MACE. There was a statistical difference between the predicted versus observed 30-day mortality and MACE. The discriminatory power of VQI MPS and RCRI were poor with c statistic of 0.664 for VQI MPS and 0.518 for RCRI. Univariate analysis showed that congestive heart failure (CHF) was the only factor that affected 30-day mortality and perioperative MACE. Conclusion: VQI MPS and RCRI did not accurately predict perioperative outcomes in CLTI patient undergoing revascularization in an Indian population. CHF was found to be the only predictor of perioperative mortality and MACE.