Intra-aortic balloon support for myocardial infarction with cardiogenic shock: insights from the Swedish Coronary Angiography and Angioplasty Registry

BACKGROUND: Cardiogenic shock remains the leading cause of in-hospital death in patients with acute myocardial infarction (MI). The intra-aortic balloon pump (IABP), once widely used, was downgraded in European guidelines after a major randomized trial showed no mortality benefit. This prospective observational study evaluated the impact of IABP on 30-day mortality and in-hospital complications in real-world patients with MI complicated by cardiogenic shock. METHODS: Data were obtained from the Swedish Coronary Angiography and Angioplasty Registry, including all percutaneous coronary intervention procedures performed across 31 hospitals in Sweden between 2005 and 2018. A total of 2991 patients with cardiogenic shock were included, of whom 737 (25%) received IABP. To account for baseline differences, instrumental variable analysis was applied using hospital treatment preference as the instrument. RESULTS: At 30 days, 52% of patients had died, and by 1 year, mortality reached 63.2%. In-hospital complications occurred in 13.4% of patients. IABP treatment was not associated with reduced mortality at 30 days [risk reduction: -1.1%, 95% confidence interval (CI): -15.7 to 13.5; P = 0.881] or at 1 year (risk reduction: -0.8%, 95% CI: -23.2 to 0.06; P = 0.258). However, IABP use was associated with a significantly higher risk of in-hospital complications (increase of 26.1%, 95% CI: 15.2-36.8; P < 0.001). CONCLUSION: IABP did not improve short- or long-term survival in patients with MI-related cardiogenic shock but was linked to increased complications, supporting current guideline recommendations against its routine use.