Unequal access to interventional cardiac care in Nova Scotia in patients with acute myocardial infarction complicated by cardiogenic shock

Background: The optimal treatment of cardiogenic shock (CS) complicating acute myocardial infarction (AMI) remains controversial and continues to be associated with a high mortality rate. The present study evaluated the outcomes of all patients having AMI complicated by CS in a single Canadian province. Methods: All consecutive patients diagnosed with AMI and CS from October 1997 to December 2002 in Nova Scotia were included in the present study. The Improving Cardiac Outcomes in Nova Scotia (ICONS) registry was used as the principal source of data. The outcome of interest was in-hospital mortality. Results: During the study period, a total of 11,300 patients with AMI were identified, with 707 complicated by CS, for an incidence of AMI+CS of 6.3%. The overall mortality rate for patients with AMI+CS was 60.1%. Multivariate regression analysis identified age older than 65 years (OR 2.0; 95% CI 1.4 to 2.9) and renal insufficiency (OR 2.1; 95% CI 1.4 to 3.2) as independent predictors of mortality, while access to invasive cardiac care (defined as admission or transfer to the only cardiac catheterization-capable centre in Halifax, Nova Scotia) was found to be an independent predictor of survival (OR 0.4; 95% CI 0.3 to 0.5). Access to invasive cardiac care was limited to 414 (59%) patients, 250 (35%) of whom actually underwent cardiac catheterization. Conclusions: Admissions to a tertiary care centre that can provide invasive care was independently associated with improved survival, and older age and renal insufficiency were associated with death among patients with AMI and CS.