One-Year Survival Following Early Revascularization for Cardiogenic Shock

Abstract

Context Cardiogenic shock (CS) is the leading cause of death for patients hospitalized with acute myocardial infarction (AMI).

Objective To assess the effect of early revascularization (ERV) on 1-year survival for patients with AMI complicated by CS.

Design The SHOCK (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock) Trial, an unblinded, randomized controlled trial from April 1993 through November 1998.

Setting Thirty-six referral centers with angioplasty and cardiac surgery facilities.

Patients Three hundred two patients with AMI and CS due to predominant left ventricular failure who met specified clinical and hemodynamic criteria.

Interventions Patients were randomly assigned to an initial medical stabilization (IMS; n = 150) group , which included thrombolysis (63% of patients), intra-aortic balloon counterpulsation (86%), and subsequent revascularization (25%), or to an ERV group (n = 152), which mandated revascularization within 6 hours of randomization and included angioplasty (55%) and coronary artery bypass graft surgery (38%).

Main Outcome Measures All-cause mortality and functional status at 1 year, compared between the ERV and IMS groups.

Results One-year survival was 46.7% for patients in the ERV group compared with 33.6% in the IMS group (absolute difference in survival, 13.2%; 95% confidence interval [CI], 2.2%-24.1%; P<.03; relative risk for death, 0.72; 95% CI, 0.54-0.95). Of the 10 prespecified subgroup analyses, only age (<75 vs ≥ 75 years) interacted significantly (P<.03) with treatment in that treatment benefit was apparent only for patients younger than 75 years (51.6% survival in ERV group vs 33.3% in IMS group). Eighty-three percent of 1-year survivors (85% of ERV group and 80% of IMS group) were in New York Heart Association class I or II.

Conclusions For patients with AMI complicated by CS, ERV resulted in improved 1-year survival. We recommend rapid transfer of patients with AMI complicated by CS, particularly those younger than 75 years, to medical centers capable of providing early angiography and revascularization procedures.

Cardiogenic shock (CS) is the leading cause of death for patients hospitalized with acute myocardial infarction (AMI), and mortality remains high during the following year. The SHOCK (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock) Trial demonstrated a nonsignificant reduction in 30-day mortality (56% vs 47%) when early revascularization (ERV) was compared with a strategy of initial medical stabilization (IMS), with a larger difference between the groups at 6 months. In this article, we report the 1-year survival, a prespecified secondary end point of the SHOCK Trial.