A New Risk Score to Predict Long-Term Cardiac Mortality in Patients With Acute Myocardial Infarction Complicated by Cardiogenic Shock and Treated With Primary Percutaneous Intervention

Abstract

Poor data exist about predictors of long-term cardiac mortality in patients presenting acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) treated with primary percutaneous coronary intervention (p-PCI), and current risk-adjustment models in this setting are not adequate. We retrospectively analyzed our registry of patients with AMI treated with p-PCI. The aim of this study was to identify the independent predictors of 2-year cardiac mortality in patients presenting CS. A Risk Score was created assigning at any independent variable a value directly correlated with its power to increase mortality. From 1995 to 2013, 4,078 consecutive patients underwent primary PCI for AMI. Of these, 388 patients (10.5%) had CS on admission. The p-PCI procedural success was 85%. At 2-year follow-up, the overall cardiac mortality rate was 48%. The independent predictors related with mortality were: out of hospital cardiac arrest (OHCA) (hazard ratio [HR] 1.51; p= 0.04), age >75years (HR 2.09; p ≤0.001), and failure p-PCI (HR 2.30; p <0.001). On the basis of the HR obtained, we assigned an incremental value to each independent variable identified (OHCA: 0.5 points, age>75 years: 1 point, failed p-PCI: 1.5 points). The mortality rates among different score risk level were highly significant (p <0.001): 32% score risk 1 (points 0), 58% score risk 2 (points 0.5-2), and 83% score risk 3 (points >2), respectively. In conclusion, OHCA, age >75years, and failed p-PCI are strong predictors of 2-year cardiac mortality. On the basis of this, a rapid score tool could be useful to identify patients at major risk of death.