Abstract 90: Ten-year Trends in Mechanical Revascularization, Intra-Aortic Balloon Pump Use and In-Hospital Mortality in Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock

Abstract

Background: Early mechanical revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock is associated with improved survival. The current guidelines also recommend (Class IIa) the use of intra-aortic balloon pump (IABP) in patients with cardiogenic shock. However, the evidence supporting this recommendation is controversial. Objectives: To examine the trends (2001-2010) in mechanical revascularization, IABP use and in-hospital mortality in patients with cardiogenic shock complicating AMI and to determine if IABP use is associated with improved in-hospital survival among these patients. Methods: We conducted a retrospective trend analysis of the Healthcare Cost and Utilization Project’s Nationwide Inpatient Sample (NIS) database from 2001-2010. All patients ≥ 40 years of age with AMI and cardiogenic shock were identified using ICD-9-CM diagnosis codes. Trends in mechanical revascularization (PCI or CABG), IABP use and in-hospital mortality were analyzed. We used logistic regression analysis to determine the association between IABP use and in-hospital mortality. Results: From 2001-2010, among 6,670,347 patients aged ≥ 40 years admitted with AMI, 287,256 (4.3%) had cardiogenic shock. The proportion of patients with cardiogenic shock complicating AMI increased from 3.7% in 2001 to 5.1% in 2010 (P trend < 0.001). There was a significant increase in mechanical revascularization rates (49.7% in 2001 to 66.3% in 2010, P trend < 0.001) as well as IABP use (38.7% in 2001 to 47.8% in 2010, P trend < 0.001) in these patients over the 10-year period. The overall in-hospital mortality among patients with AMI and cardiogenic shock decreased from 48.6% in 2001 to 32.7% in 2010 (P trend < 0.001). When adjusted for demographics, cardiovascular risk factors and mechanical revascularization status, IABP use was associated with higher in-hospital mortality (adjusted OR 1.14, 95% CI 1.11-1.16, P<0.001). Similarly, in the subgroup of patients who underwent mechanical revascularization, in-hospital mortality was higher among those with IABP placement (adjusted OR 1.39, 95% CI 1.35-1.43, P <0.001). Conclusion: Mechanical revascularization rates in patients with cardiogenic shock complicating AMI have increased during the past decade. This is also associated with a decrease in in-hospital mortality during this period. IABP use has also increased over the past 10 years; however, IABP use is associated with higher in-hospital mortality among patients with AMI and cardiogenic shock.