Increased cardiac troponin I on admission predicts in-hospital mortality in acute pulmonary embolism

Abstract

Background: To investigate the frequency of cardiac troponin I (cTnI) increases in patients with pulmonary embolism (PE) and to assess the correlation between this finding, the clinical presentation, and outcomes. Methods: Consecutive patients admitted to the coronary care unit with acute PE were prospectively enrolled between January 2000 and December 2001. cTnI was sequentially determined. Various cut off concentrations were analysed, but patients were categorised prospectively as having increased or no increased cTnI based on a cut off concentration of 0.6 ng/ml. The main outcome measure was in-hospital mortality. Results: On admission, 14 of the 48 patients (29%) had cTnI concentrations greater than the receiver operating characteristic curve value used to diagnose acute myocardial infarction (> 0.6 ng/ml). Subsequently, six patients developed increases for an overall prevalence of 42% (20 of 42). The prevalence was higher when lower cut off concentrations were used: 73% (35 of 48) at the 99th centile and 60% (29 of 48) at the 10% coefficient of variability. Increased cTnI > 0.6 ng/ml was associated with a slower oxygen saturation (86 (7)% v 93 (4)%, p < 0.0001) and more frequent involvement of the main pulmonary arteries as assessed by spiral computed tomography (100% v 60%, p = 0.022). In-hospital mortality was 36% (5 of 14) of patients with increases > 0.6 ng/ml v 3% (1 of 42) of patients with lower concentrations (p = 0.008). Increased cTnI > 0.6 ng/ml on admission was the most powerful predictor of mortality (p = 0.046). Conclusions: In high risk patients with acute PE, cTnI was frequently detected on admission. It was the strongest independent predictor of mortality.