Intra-aortic Balloon Pump Therapy for Anterior ST-elevation Myocardial Infarction with Cardiogenic Shock: An Observational Cohort Study

Abstract

Background As a mechanical circulatory assistance, intra-aortic balloon pump (IABP) has been widely used for cardiogenic shock (CS), although recent clinical trials questioned its impact on acute myocardial infarction patients, nothing is hitherto known on the contribution of IABP to CS patients after anterior wall infarction. The aim of this study was to investigate the efficacy and safety of IABP therapy in patients presenting with anterior ST-elevation myocardial infarction (STEMI) complicated by CS.Methods We conducted a retrospective study of 215 consecutive patients presenting with CS after STEMI in the anterior wall between January 2006 and August 2017, including 125 patients in the IABP group and 90 patients in the control group.Results At 30 days, 60 (48.0%) patients in the IABP group and 58 (64.4%) patients in the control group had died (P=0.017). The Kaplan-Meier survival curves showed the cumulative survival rate in the IABP group was consistently higher than control group (P=0.009 by Log-Rank test). Nevertheless, IABP increased the occurrence of thrombocytopenia (21.6% vs. 2.2%, P<0.001) and lower limb complications (20.0% vs. 2.2%, P<0.001) at the same time. Subgroup analyses by Cox regression showed a better trend of prognoses in patients aged less than 60 years old (HR=0.49, 95% CI=0.26-0.91, P=0.025), male (HR=0.53, 95% CI=0.34-0.83, P=0.005), no history of hypertension (HR=0.47, 95% CI=0.26-0.87, P=0.017) and systolic blood pressure less than 80 mm Hg (HR=0.40, 95% CI=0.22-0.73, P=0.009). At 12-month follow-up, all-cause mortality in the IABP group was obviously lower than the control group (52.5% vs. 74.1%, P=0.002), there were no significant differences in other adverse cardiovascular events (P=1.000).Conclusions The combination of IABP use is associated with reduced 30-day and 12-month mortality in patients with anterior STEMI complicated by CS, though thrombocytopenia and lower limb complications are frequently observed.