Abstract
BACKGROUND: Type 2 myocardial infarction (MI) (T2MI) is common and associated with adverse outcomes. OBJECTIVES: The objective of the study was to evaluate the prevalence of coronary artery disease (CAD) in patients with T2MI and myocardial injury and its impact on outcomes. METHODS: Observational U.S. cohort study of emergency department patients undergoing high-sensitivity cardiac troponin T measurement. Cases with >1 high-sensitivity cardiac troponin T increase >99th percentile were adjudicated following the Fourth Universal Definition of MI. CAD was defined as a prior CAD, MI, or coronary revascularization or newly diagnosed CAD during index hospitalization. Two-year major adverse cardiovascular outcomes including all-cause, cardiovascular, and noncardiovascular death, acute MI, heart failure hospitalization, and coronary revascularization were compared between patients with T2MI or myocardial injury and CAD vs type 1 MI (T1MI). RESULTS: Among 858 patients, 64 (7.5%) had T1MI, 91 (11%) had T2MI, and 703 (82%) had myocardial injury. Patients with T2MI and CAD (n = 31; 34% of T2MI) had higher major adverse cardiovascular outcomes than T1MI (65% vs 39%; adjusted HR [aHR]: 1.95; 95% CI: 1.2-3.6), driven by higher all-cause death (52% vs 20%; aHR: 2.2; 95% CI: 1.0-4.5), noncardiovascular death (26% vs 5%; aHR: 5.04; 95% CI: 1.3-19.3), acute MI (13% vs 2%; aHR: 9.2; 95% CI: 1.01-84.2), and heart failure hospitalization (32% vs 8%; aHR: 4.6; 95% CI: 1.6-13.7). Patients with myocardial injury and CAD (n = 245) demonstrated similar trends, although differences were not statistically significant after adjustment. CONCLUSIONS: CAD is common among patients with T2MI and myocardial injury and is associated with poor long-term outcomes. Its presence may facilitate risk-stratification and represent a potential therapeutic target.