Comparison of troponin I and N-terminal-pro B-type natriuretic peptide for risk stratification in patients with pulmonary embolism

Objective We compared the usefulness of plasma N-terminal-pro B-type natriuretic peptide and troponin I levels for risk stratification of patients with pulmonary embolism. Methods This was a prospective study performed in an emergency department. N-terminal-B-type natriuretic peptide assay and troponin I were performed blindly at admission in patients with pulmonary embolism confirmed by imaging tests. A complicated pulmonary embolism was defined as any of the following: death, cardiopulmonary resuscitation, requirement for mechanical ventilation, use of pressors, thrombolysis, surgical embolectomy or admission in an intensive care unit. Results Sixty patients (mean age standard deviation of 72 15 years) were included. Seventeen (28%) patients had adverse events: all were admitted in intensive care unit, one was treated with surgical embolectomy and one with thrombolysis, and three died. The median N-terminal-pro B-type natriuretic peptide level (95% confidence interval) was higher in the group of patients with complicated pulmonary embolism, 4086 pg/ml (505-8998) versus 352pg/ml (179-662), respectively (P < 0.05). The mean value of troponin I was similar in the complicated pulmonary embolism group, 0.09 +/- 0.17 mu g/I versus 0.08 +/- 0.41 mu g/I, respectively (P=0.93). The best threshold value of N-terminal-pro 13-type natriuretic peptide was 1000 pg/ml, and the receiver operating characteristic curve demonstrated that N-terminal-pro B-type natriuretic peptide significantly predicted the complicated pulmonary embolism with an area under the receiver operative curve of 0.72 (0.58-0.83) (P < 0.05), whereas troponin I did not [area under the receiver operative curve of 0.58 (0.42-0.71)]. Conclusion Unlike troponin I, N-terminal-pro B-type natriuretic peptide may be an accurate marker of in-hospital complication after pulmonary embolism.