Clinical usefulness of troponin I in acute pulmonary embolism

BACKGROUND: Troponin-I (cTp-I) is considered a sensitive biomarker of myocardial injury in acute pulmonary thromboembolism (PE) with prognosis implications, though abnormal levels vary among reports. PATIENTS AND METHODS: cTp-I was measured in consecutive patients objectively diagnosed of PE by means of pulmonary angiography made with helicoidal CT. Patients were classified radiologically as central or peripheral PE and hemodynamically as massive, submassive or non-massive according to the pulmonary vessel occluded and systolic blood pressure and ProBNP levels respectively. We checked also the delay in diagnosis (DD) and 30-days all-causes mortality rate. RESULTS: We evaluated 164 patients; the mean age was 70 (15) years, males: 76 (46%). Median DD was 5 [interquartile range (IQ) 12) days. Median cTp-I in patients with DD>5 was 0.003microg/L (IQ 0.072)microg/L while in patients with DD<5 was 0.05microg/L (IQ 0.096) (p<0.05). cTp-I higher than 0.5microg/L occurred in 11 (7%) patients. Levels of cTp-I higher than 0.03microg/L were associated with central PE, (AUROC 0.7059 CI95% 0.6643-0.7475, sensitivity 0.75, specificity 0.69, PPV 0.75 and NPV 0.69) and massive and submassive PE (AUROC 0.7685, CI95% 0.7288-0.8082 sensitivity 0.86, specificity 0.66, PPV 0.72 and NPV 0.82), but they were not associated with mortality (AUROC 0.5394). In a multivariate analysis cTp-I did not show to be an independent predictor of central, massive and submassive PE or all causes death. CONCLUSIONS: In this study cTp-I was not a proper biomarker of the size of pulmonary vessel occluded, the degree of hemodynamic derangement or short-term mortality. The delay in diagnosis could influence the usefulness of cTp-I.