The incidence and prognostic significance of elevated cardiac troponins in patients with submassive pulmonary embolism

Although the incidence and prognostic significance of elevated cardiac troponins are known in patients with massive pulmonary embolism (PE), few studies have addressed this issue in patients with hemodynamically stable, submassive PE, who comprise the majority of patients presenting with PE. This prospective cohort study was, therefore, designed to determine the incidence and prognostic significance of elevated cardiac troponins in patients with submassive PE. Consecutive patients with acute, symptomatic, submassive PE that was confirmed by objective diagnostic testing were studied. All patients received treatment with either unfractionated heparin or fondaparinux followed by a coumarin derivative and underwent clinical follow-up for 3 months. Cardiac troponin I (cTnI) levels were measured within 24 h of clinical presentation. An elevated cTnI was defined as > 0.5 microg L(-1) and indicated myocardial injury. Major myocardial injury, that is associated with myocardial infarction, was defined by a cTnI > 2.3 microg L(-1). The clinical outcomes were recurrent venous thromboembolism and all-cause death. In 458 patients with submassive PE, the incidence of cTnI > 0.5 microg L(-1) was 13.5%[95% confidence interval (CI): 10.4-16.7], and the incidence of cTnI > 2.3 microg L(-1) was 3.5% (95% CI: 2.0-5.6). An elevated cTnI > 0.5 microg L(-1) was associated with an increased risk of all-cause death [odds ratio (OR) = 3.5; 95% CI: 1.0-11.9], but did not appear to confer an increased risk of recurrent venous thromboembolism (OR = 1.1; 95% CI: 0.2-4.9). In patients who present with submassive PE, an elevated cTnI occurs in about one in seven patients and is associated with a 3.5-fold increased risk of all-cause death.