Utility of Intra-Aortic Balloon Pump Support for Ventricular Septal Rupture and Acute Mitral Regurgitation Complicating Acute Myocardial Infarction

Abstract

Clinical data on optimal management of mechanical complications of myocardial infarction are lacking. We retrospectively evaluated the effect of intra-aortic balloon pump (IABP) on 30-day survival in patients with postinfarction ventricular septal rupture (VSR, n= 55) or acute mitral regurgitation (MR, n= 26) who developed either cardiogenic shock (n= 46) or severe hemodynamic instability that did not fulfill the criteria of shock (n= 35). IABP was inserted in 83% of the patients with shock and 57% of those without shock. Thirty-five (76%) patients with shock and all unstable patients survived until surgical repair, which was performed within a median (interquartile range) of 1 (1 to 2) and 9 (2 to 18) days from the onset of the complication (p <0.001). All patients who did not undergo the operation died within 3days. Although MR presented more acutely, the patients' outcomes were similar to those with VSR. IABP support reduced 30-day mortality in the patients with shock (61% vs 100%, p= 0.04) but not in the patients without shock (20% vs 27%, p= 0.7). The benefit of IABP support in the shock cohort was driven mainly by reduction of preoperative mortality (11% vs 88%, p <0.001). Early progression of cardiogenic shock and unperformed surgery were the only independent predictors of 30-day mortality (hazard ratio 3.4, 95% confidence interval 1.5 to 8 and hazard ratio 5.1, 95% confidence interval 2.2 to 11, respectively; p= 0.004 and p <0.001, respectively). In conclusion, we suggest that all patients with postinfarction VSR or acute MR with signs of cardiogenic shock should immediately receive IABP as a bridge to emergent surgical repair. In contrast, hemodynamically unstable patients without shock may be first stabilized by medical therapy, without additional benefit of IABP, before they undergo cardiac surgery.