Efficacy of Intra-aortic Balloon Pump before versus after Primary Percutaneous Coronary Intervention in Patients with Cardiogenic Shock from ST-elevation Myocardial Infarction

BACKGROUND: Previous studies showed that patients with cardiogenic shock (CS) from ST-elevation acute myocardial infarction (STEMI) supported by intra-aortic balloon pump (IABP) before primary percutaneous coronary intervention (PCI) decreased the risk of in-hospital mortality than patients who received IABP after PCI. However, little evidence is available on the optimal order of IABP insertion and primary PCI. The aim of this study was to investigate the impact of the sequence of IABP support and PCI and its association with major adverse cardiac and cerebrovascular events (MACCEs). METHODS: Data were obtained from 218 consecutive patients with CS due to STEMI in Beijing Anzhen Hospital between 2008 and 2014, who were treated with IABP and PCI. The patients were divided into two groups: Group A in whom IABP received before PCI (n = 106) and Group B in whom IABP received after PCI (n = 112). We evaluated the myocardial perfusion using myocardial blush grade and resolution of ST-segment elevation. The primary endpoint was 12-month risk of MACCE. RESULTS: Most baseline characteristics were similar in patients between the two groups. However, patients received IABP before PCI were associated with a delay of door-to-balloon time (DBT) and higher troponin I level (P < 0.05). However, myocardial perfusion was significantly improved in patients treated with IABP before PCI (P < 0.05). Overall, IABP support before PCI was not associated with significantly lower risk of MACCE (P > 0.05). In addition, risk of all-cause mortality, bleeding, and acute kidney injury (AKI) was similar between two groups (P > 0.05). Multivariate analysis showed that DBT (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.1–4.8, P = 0.04), IABP support after PCI (OR 5.7, 95% CI 2.7–8.4, P = 0.01), and AKI (OR 7.4, 95% CI 4.9–10.8, P = 0.01) were the independent predictors of mortality at 12-month follow-up. CONCLUSIONS: Early IABP insertion before primary PCI is associated with improved myocardial perfusion although DBT increases. IABP support before PCI does not confer a 12-month clinical benefit when used for STEMI with CS.