Early revascularization in acute myocardial infarction complicated by cardiogenic shock. SHOCK Investigators. Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock

Abstract

Background: The leading cause of death in patients hospitalized for acute myocardial infarction is cardiogenic shock. We conducted a randomized trial to evaluate early revascularization in patients with cardiogenic shock.

Methods: Patients with shock due to left ventricular failure complicating myocardial infarction were randomly assigned to emergency revascularization (152 patients) or initial medical stabilization (150 patients). Revascularization was accomplished by either coronary-artery bypass grafting or angioplasty. Intraaortic balloon counterpulsation was performed in 86 percent of the patients in both groups. The primary end point was mortality from all causes at 30 days. Six-month survival was a secondary end point.

Results: The mean age of the patients was 66+/-10 years, 32 percent were women and 55 percent were transferred from other hospitals. The median time to the onset of shock was 5.6 hours after infarction, and most infarcts were anterior in location. Ninety-seven percent of the patients assigned to revascularization underwent early coronary angiography, and 87 percent underwent revascularization; only 2.7 percent of the patients assigned to medical therapy crossed over to early revascularization without clinical indication. Overall mortality at 30 days did not differ significantly between the revascularization and medical-therapy groups (46.7 percent and 56.0 percent, respectively; difference, -9.3 percent; 95 percent confidence interval for the difference, -20.5 to 1.9 percent; P=0.11). Six-month mortality was lower in the revascularization group than in the medical-therapy group (50.3 percent vs. 63.1 percent, P=0.027).

Conclusions: In patients with cardiogenic shock, emergency revascularization did not significantly reduce overall mortality at 30 days. However, after six months there was a significant survival benefit. Early revascularization should be strongly considered for patients with acute myocardial infarction complicated by cardiogenic shock.