One-year survival following early revascularization for cardiogenic shock

Context Cardiogenic shock (CS) is the leading cause of death for patients h ospitalized with acute myocardial infarction (AMI), Objective To assess the effect of early revascularization (ERV) on 1-year s urvival for patients with AMI complicated by CS. Design The SHOCK (Should We Emergently Revascularize Occluded Coronaries fo r Cardiogenic Shock) Trial, an unblinded, randomized controlled trial from April 1993 through November 1998, Setting Thirty-six referral centers with angioplasty and cardiac surgery fa cilities. 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 stabili zation (IMS; n =150) group, which included thrombolysis (63% of patients), intra-aortic balloon counterpulsation (86%), and subsequent revascularizati on (25%), or to an ERV group (n=152), which mandated revascularization with in 6 hours of randomization and included angioplasty (55%) and coronary art ery 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% co nfidence interval [CI], 2.2%_24.1%; P<.03; relative risk for death, 0.72; 9 5% CI, 0.54-0.95). Of the 10 prespecified subgroup analyses, only age (<75 vs greater than or equal to 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) w ere in New York Heart Association class I or II. Conclusions For patients with AMI complicated by CS, ERV resulted in improv ed 1-year survival. We recommend rapid transfer of patients with AMI compli cated by CS, particularly those younger than 75 years, to medical centers c apable of providing early angiography and revascularization procedures.