Clinical Outcomes and Cost Associated With an Intravascular Microaxial Left Ventricular Assist Device vs Intra-aortic Balloon Pump in Patients Presenting With Acute Myocardial Infarction Complicated by Cardiogenic Shock

Abstract

Importance: Intravascular microaxial left ventricular assist device (LVAD) compared with intra-aortic balloon pump (IABP) has been associated with increased risk of mortality and bleeding among patients with acute myocardial infarction (AMI) and cardiogenic shock (CS) undergoing percutaneous coronary intervention (PCI). However, evidence on the association of device therapy with a broader array of clinical outcomes, including data on long-term outcomes and cost, is limited.

Objective: To examine the association between intravascular LVAD or IABP use and clinical outcomes and cost in patients with AMI complicated by CS.

Design, setting, and participants: This retrospective propensity-matched cohort study used administrative claims data for commercially insured patients from 14 states across the US. Patients included in the analysis underwent PCI for AMI complicated by CS from January 1, 2015, to April 30, 2020. Data analysis was performed from April to November 2021.

Exposures: Use of either an intravascular LVAD or IABP.

Main outcomes and measures: The primary outcomes were mortality, stroke, severe bleeding, repeat revascularization, kidney replacement therapy (KRT), and total health care costs during the index admission. Clinical outcomes and cost were also assessed at 30 days and 1 year.

Results: Among 3077 patients undergoing PCI for AMI complicated by CS, the mean (SD) age was 65.2 (12.5) years, and 986 (32.0%) had cardiac arrest. Among 817 propensity-matched pairs, intravascular LVAD use was associated with significantly higher in-hospital (36.2% vs 25.8%; odds ratio [OR], 1.63; 95% CI, 1.32-2.02), 30-day (40.1% vs 28.3%; OR, 1.71; 95% CI, 1.37-2.13), and 1-year mortality (58.9% vs 45.0%; hazard ratio [HR], 1.44; 95% CI, 1.21-1.71) compared with IABP. At 30 days, intravascular LVAD use was associated with significantly higher bleeding (19.1% vs 14.5%; OR, 1.35; 95% CI, 1.04-1.76), KRT (12.2% vs 7.0%; OR, 1.88; 95% CI, 1.30-2.73), and mean cost (+$51 680; 95% CI, $31 488-$75 178). At 1 year, the association of intravascular LVAD use with bleeding (29.7% vs 24.3%; HR, 1.36; 95% CI, 1.05-1.75), KRT (18.1% vs 10.9%; HR, 1.95; 95% CI, 1.35-2.83), and mean cost (+$46 609; 95% CI, $22 126-$75 461) persisted.

Conclusions and relevance: In this propensity-matched analysis of patients undergoing PCI for AMI complicated by CS, intravascular LVAD use was associated with increased short-term and 1-year risk of mortality, bleeding, KRT, and cost compared with IABP. There is an urgent need for additional evidence surrounding the optimal management of patients with AMI complicated by CS.

Figure 1.. Flow Diagram

AMI indicates acute myocardial infarction; ECMO, extracorporeal membrane oxygenation; IABP, intra-aortic balloon pump; LVAD, left ventricular assist device; PCI, percutaneous coronary intervention.

Figure 2.. Proportion of Patients Receiving an Intravascular Left Ventricular Assist Device (LVAD) vs Intra-aortic Balloon Pump (IABP) Over Time

Figure 3.. Clinical Outcomes Among Propensity-Matched Patients Receiving an Intravascular Left Ventricular Assist Device (LVAD) vs Intra-aortic Balloon Pump (IABP)

Odds ratios are for outcomes during the index hospitalization and at 30 days; hazard ratios are for outcomes at 1 year.

Figure 4.. Kaplan-Meier Curves for 1-Year Mortality Among Propensity-Matched Patients Receiving an Intravascular Left Ventricular Assist Device (LVAD) vs Intra-aortic Balloon Pump (IABP)