Clinical Features and Prognosis of Patients with Acute and Chronic Myocardial Injury Admitted to the Emergency Department.

Background: This study aimed to investigate the clinical features and prognosis of acute and chronic myocardial injury without clinical evidence of myocardial infarction in patients admitted to the emergency department.

Methods: We analyzed the clinical data of all consecutive patients admitted to the emergency department during the years 2012 and 2013 who had at least 2 determinations of troponin I (TnI Ultra Siemens, Advia Centaur) and without a diagnosis of myocardial infarction. Clinical events were evaluated in a 3-year follow-up.

Results: A total of 1201 patients met the study's inclusion criteria and were included in the analysis (833 with cTnI below the 99th percentile, 261 with acute myocardial injury, and 107 with chronic myocardial injury). During a median follow-up of more than 36 months, mortality and rehospitalization for heart failure were significantly higher in patients with acute or chronic myocardial injury compared with patients without myocardial injury. No differences were observed in overall mortality between patients with acute and chronic myocardial injury, or in the rate of readmission due to acute coronary syndrome. However, the risk of readmission due to heart failure (adjusted HR 2.17; 95% confidence interval, 1.26-3.75; P = .005) was higher in patients with chronic myocardial injury.

Conclusions: Mortality in long-term follow-up is high and similar in acute and chronic myocardial injury; however, the risk of readmission due to heart failure is higher in patients with chronic myocardial injury compared with patients with acute myocardial injury.