Trends in Intra-Aortic Balloon Pump Use in Cardiogenic Shock After the SHOCK-II Trial

Myocardial infarction complicated by cardiogenic shock (MI-CS) has a poor prognosis, even with early revascularization. Previously, intra-aortic balloon pump (IABP) use was thought to improve outcomes, but the IABP-SHOCK-II (Intra-aortic Balloon Pump in Cardiogenic Shock-II study) trial found no survival benefit. We aimed to determine the trends in IABP use in patients who underwent percutaneous intervention over time. Data were taken from patients in the Melbourne Interventional Group registry (2005 to 2018) with MI-CS who underwent percutaneous intervention. The primary outcome was the trend in IABP use over time. The secondary outcomes included 30-day mortality and major adverse cardiovascular and cerebrovascular events (MACCEs). Of the 1,110 patients with MI-CS, IABP was used in 478 patients (43%). IABP was used more in patients with left main/left anterior descending culprit lesions (62% vs 46%), lower ejection fraction (<35%; 18% vs 11%), and preprocedural inotrope use (81% vs 73%, all p <0.05). IABP use was associated with higher bleeding (18% vs 13%) and 30-day MACCE (58% vs 51%, both p <0.05). The rate of MI-CS per year increased over time; however, after 2012, there was a decrease in IABP use (p <0.001). IABP use was a predictor of 30-day MACCE (odds ratio 1.6, 95% confidence interval 1.18 to 2.29, p = 0.003). However, IABP was not associated with in-hospital, 30-day, or long-term mortality (45% vs 47%, p = 0.44; 46% vs 50%, p = 0.25; 60% vs 62%, p = 0.39). In conclusion, IABP was not associated with reduced short- or long-term mortality and was associated with increased short-term adverse events. IABP use is decreasing but is predominately used in sicker patients with greater myocardium at risk.