The use of intra-aortic balloon counterpulsation in patients with cardiogenic shock complicating acute myocardial infarction: Data from the National Registry of Myocardial Infarction 2

Background Cardiogenic shock complicating acute myocardial infarction (AMI) remains the leading cause of death in patients hospitalized with AMI. Alth ough several studies have demonstrated the importance of establishing and m aintaining a potent infarct-related artery, it remains unclear as to whethe r intra-aortic balloon counterpulsation (IABP) provides incremental benefit to reperfusion therapy. The purpose of this study was to determine whether IABP use is associated with lower in-hospital mortality rates in patients with AMI complicated by cardiogenic shock in a large AMI registry. Methods We evaluated patients participating in the National Registry of Myo cardial Infarction 2 who had cardiogenic shock at initial examination or in whom cardiogenic shock developed during hospitalization (n = 23,180). Results The mean age of patients in the study was 72 years, 54% were men, a nd the majority were white. The overall morality rate in all patients who h ad cardiogenic shock or in whom cardiogenic shock developed was 70%. IABP w as used in 7268 (31%) patients. IABP use was associated with a significant reduction in mortality rates in patients who received thrombolytic therapy (67% vs 49%) but was not associated with any benefit in patients treated wi th primary angioplasty (45% vs 47%). In a multivariate model, the use of IA BP in conjunction with thrombolytic therapy decreased the odds of death by 18% (odds ratio, 0.82; 95% confidence interval, 0.72 to 0.93). Conclusions Patients with AMI complicated by cardiogenic shock may have sub stantial benefit from IABP when used in combination with thrombolytic thera py.