Myoglobin stratifies short-term risk in acute major pulmonary embolism

Background: Concentrations of cardiac troponins can be elevated in acute pulmonary embolism (APE) indicating myocardial injury. Although concentration of myoglobin (MYO) increases after myocardial damage, even before detectable rise of cardiac troponin levels occurs, MYO was not evaluated in APE. Therefore, we assessed prevalence and prognostic significance of myoglobin in major APE. Methods: We studied 46 patients (30 women, aged 61.9±17.8 years) with major APE defined with right ventricular dilatation. On admission serum myoglobin, and cardiac troponin T (cTnT) were measured. Serum MYO concentrations >58 ng/ml for women, and >72 ng/ml for men were considered abnormal. CTnT>0.01 ng/ml was regarded to indicate myocardial injury. Results: MYO levels exceeding sex specific norms were found in 21/46 (45.7%) of patients, while detectable cTnT was found in 24/46 (52.1%) of patients. Seven patients died during hospitalization. Elevated MYO significantly predicted in-hospital mortality (OR 25, 95% CI 1.3–474.2), while increased cTnT concentration did not affect the survival. Among clinical and echocardiographic variables only older age indicated worse prognosis (OR 1.6, 95% CI 1.06–2.41). Conclusions: Myoglobin levels are elevated in serum on admission in almost half of patients with major APE. Elevated myoglobin level, marker of myocardial injury, is a powerful predictor of increased risk of fatal outcome in major pulmonary embolism.