Cardiac troponins are reliable markers of myocardial injury that are being used increasingly in patients presenting with undifferentiated chest pain or dyspnea to diagnose an acute coronary syndrome. If elevated cardiac troponin levels also occur in patients with pulmonary embolism because of right ventricular dilation and myocardial injury, such patients could be misdiagnosed. We performed a prospective cohort study to determine the prevalence of elevated cardiac troponin I (cTnI) levels in patients with submassive pulmonary embolism.
Consecutive patients with objectively confirmed submassive pulmonary embolism and no previous history of ischemic heart disease, other cardiac disease, or renal insufficiency were included. Creatine kinase and cTnI levels were measured within 24 hours of clinical presentation on 2 occasions 8 to 12 hours apart.
Of 24 patients with submassive pulmonary embolism, 5 (20.8%) had elevated cTnI levels of 0.4 µg/L or higher (95% confidence interval, 7.1-42.2%). One of these patients had a cTnI level higher than 2.3 µg/L that was suggestive of myocardial infarction.
Pulmonary embolism should be considered in the differential diagnosis of patients presenting with undifferentiated chest pain or dyspnea and an elevated cardiac troponin level.