Combined risk stratification with computerized tomography /echocardiography and biomarkers in patients with normotensive pulmonary embolism

Background

Right ventricular dysfunction (RVD) detected by computerized tomography (CT)/echocardiography or elevated biomarkers is associated with a poor prognosis for pulmonary embolism (PE). However, these prognostic factors have not previously been concomitantly elucidated in the same patient group.

Methods

This prospective study included 108 consecutive patients with normotensive PE confirmed by CT pulmonary angiography (CTPA). On admission, patient serum NT-proBNP and troponin T (Tn-T) levels were measured, and echocardiography was performed within 24 hours after diagnosis of PE. Receiver operating characteristic (ROC) analysis was performed to determine the optimal echocardiographic end-diastolic diameters of the right ventricle, the ratio of the right ventricle to left ventricle (RV/LV ratio) on CTPA, and NT-proBNP and Tn-T cut-off levels with regard to prognosis.

Results

All-cause 30-day mortality was 13% and PE-related mortality was 5.6%. RVD was defined as a right/left ventricular dimension ratio ≥ 1.1 on CTPA and RV > 30 mm on echocardiography by ROC analysis. A cut-off level of NT-proBNP ≤ 90 pmol/ml had a high positive predictive value of 98% for survival, whereas NT-proBNP > 300 and Tn-T ≥ 0.027 had a negative predictive value, for all-cause deaths, of 95% and 96%, respectively. PE mortality in patients with NT-proBNP > 300 and Tn-T ≥ 0.027 reached 64%. In univariable analysis, the combination of Tn-T ≥ 0.027 ng/ml with a echocardiographic RVD were the most significant predictors of overall mortality and PE-related death [HR: 14 (95% CI: 4.6–42,) and HR: 37.6 (95% CI: 4.4–324)], respectively. In multivariable Cox's regression analysis, NT-proBNP > 300 and Tn-T ≥ 0.027 HR: 26.5 (95% CI: 4.1-169.9, p < 0.001) were the best combination to predict all-cause of mortality.

Conclusions

The combination of NT-proBNP and Tn-T clearly appears to be a better risk stratification predictor than biomarkers plus RVD on CT/ echocardiography in patients with normotensive PE.