Predictors of Survival to Hospital Discharge with IABP Use in Acute Myocardial Infarction with Cardiogenic Shock

Purpose Landmark trial data suggests intra-aortic balloon pump (IABP) use does not reduce mortality in patients with acute myocardial infarction and cardiogenic shock (AMI-CS). However, significant heterogeneity in shock severity exists in AMI-CS cohorts. Predictors of survival in AMI-CS managed with IABP have not been fully studied. Methods We performed a single center retrospective analysis of patients presenting with AMI-CS that underwent IABP insertion between 2014 and 2019. Survival data was obtained using EMR vital status query. We reviewed demographic, vitals, laboratory, EKG, catheterization, and hemodynamic data when available. Wilcoxon rank-sum test was used for continuous variable comparisons between patients who died before discharge and patients who survived to hospital discharge after IABP insertion. Chi-square or fisher exact tests were used to test association of categorical variables with the outcome variable. Results Of the 120 patients included in the study, 84 patients (70%) survived the hospitalization. Univariate analysis showed that survivors to hospital discharge were younger (mean age=62.71±11.85 vs 67.1±12.01; P=0.024), presented with lower INR (mean=1.23± 0.30 vs 1.85±0.75), serum creatinine (mean= 1.42±0.99 vs 1.91±1.15; P=0.002), and lactic acid (mean=2.65±2.15 vs 6.1±5.1; P=0.0007). Patients who survived had higher serum hemoglobin (mean= 12.85±2.57 vs 10.87±3.26 P= 0.0002), and were much less likely to be on inotrope or pressor support prior to IABP insertion (38% vs 83%, p= 1.39 E-05). Conclusion In this single center retrospective study of AMI-CS patients managed with IABP, several clinical variables were significantly associated with survival to hospital discharge and suggested an earlier or less severe stage of shock. Our findings highlight the need for additional studies to define predictors of survival in AMI-CS managed with IABP, which may guide optimal selection of a subset of AMI-CS that has favorable outcomes with IABP support.