Short-term mortality in patients with myocardial injury and myocardial infarction type 1 and type 2

Introduction: Troponin elevations occur in a myriad of clinical conditions other than myocardial infarction (MI) and imply a poor prognosis. So far, data comparing the short-term outcome in patients with myocardial injury vs. patients with type 1 or type 2 MI are not available Methods: Over a 1-year period we prospectively studied hospitalized patients having cardiac troponin I (cTnI) measured on clinical indication. The diagnosis of type 1 and type 2 MI was according to the universal definition involving a rising and/or falling pattern of cTnI values above the decision limit of 30 ng/L. cTnI elevations above this limit in patients without overt myocardial ischemia were defined as myocardial injury. A 1-month follow-up was done with mortality as endpoint Results: The study covered 1577 consecutive patients with cTnI values >30 ng/L, of whom 360 had a type 1 MI, 119 a type 2 MI and 1089 had myocardial injury. Type 1 MI patients were younger with a median age of 70 (IQR 61-81) yrs, whereas the median ages in type 2 MI and myocardial injury were higher but comparable : 78 (IQR 67-84) vs. 77 (IQR 67-85) yrs. Peak cTnI values, however, were highest in type 1 MI: 3820 (530-19030) ng/L, lower in type 2 MI: 850 (390-3270) ng/L, and smallest in patients with myocardial injury: 90 (50-270) ng/L (p=0.0001). At one-month follow-up 285 patients had died. Mortality in the different subgroups was: 9% (33/360) in type 1 MI, 24% (28/119) in type 2 MI, and 21% (224/1089) in patients with myocardial injury. The results are depicted in the figure (Kaplan-Meier curves, log-rank-test; p-value