Cardiogenic shock as a complication of acute myocardial infarction: a nationwide cohort study.

Cardiogenic shock (CS) is a life-threatening complication of acute myocardial infarction (AMI). This study aimed to assess real-world incidence, characteristics, and outcomes in relation to age among patients with AMI complicated by CS (AMI-CS) compared to those without CS in a nationwide cohort. Cohort study of all patients <85 years with AMI registered in the Norwegian Myocardial Infarction Registry 2013-2022. Outcomes were short- and long-term all-cause mortality. Mortality was assessed by Kaplan-Meier survival curves, Life Tables, and multivariable Cox regression models. Among 86,730 AMI patients (40% women), 1,645 (2.7%) patients <75 years and 969 (3.9%) patients 75-84 years developed CS. Regardless of age, patients with AMI-CS were more likely to have previous heart failure, diabetes, renal failure, and ST-elevation AMI compared to patients without CS. In-hospital mortality was 47.5% in AMI-CS patients <75 years and 71.4% in patients 75-84 years, and the estimated one year cumulative mortality rates were 54.7% (95% CI: 52.3-57.1%) and 79.8% (95% CI: 77.2-82.3), respectively. Patients with AMI-CS who survived to hospital discharge remained at a higher long-term mortality risk compared to patients without CS (<75 years: adjusted HR 1.91 (95% CI 1.67-2.18), 75-84 years: adjusted HR 1.65 (95% CI: 1.41-1.93)). The in-hospital mortality rates for AMI-related CS remain high, especially in patients ≥75 years. However, long-term mortality in CS patients surviving to hospital discharge was only moderately higher compared to AMI patients without CS.