Intra-Aortic Balloon Pump Use in Post-Infarction Ventricular Septal Rupture: The Impact of Timing Relative to Cardiogenic Shock.

Background: Ventricular septal rupture (VSR) following acute myocardial infarction (AMI) creates an abrupt left-to-right shunt that can progress to cardiogenic shock (CS). Once CS develops, mortality increases dramatically and delayed repair becomes less feasible. Intra-aortic balloon pumps (IABPs) are widely used to facilitate delayed repair; however, whether initiating IABP before CS onset improves survival remains unclear. Methods: We retrospectively analyzed 124 patients with AMI-related VSR (2009-2024), categorized by IABP timing relative to CS onset (defined as first catecholamine administration) into pre-CS, post-CS, and no-IABP groups. The primary outcome was all-cause mortality within 90 days after AMI onset. Kaplan-Meier curves and Cox proportional hazards models were applied, with subgroup analyses by CS status. Results: The 90-day survival rate was 68.2% in the pre-CS IABP group, 14.3% in the post-CS group, and 35.1% in the no-IABP group. Pre-CS IABP was associated with significantly lower mortality compared with no-IABP (adjusted HR = 0.401, 95% CI 0.174-0.925, p = 0.032) and post-CS IABP (adjusted HR = 0.369, 95% CI 0.149-0.910, p = 0.030). In the CS subgroup, IABP use did not improve survival (19.4% vs. 17.6%, p = 0.365). Among non-CS patients, IABP use was independently associated with lower mortality (85.7% vs. 50.0%, p = 0.027; adjusted HR = 0.178, 95% CI 0.040-0.801, p = 0.025). Conclusions: Given the retrospective design and limited sample size, these findings are hypothesis-generating. Early IABP use was associated with improved short-term survival, an effect not observed once CS had developed. These findings support early risk stratification to identify high-risk patients who may benefit from timely hemodynamic support.