Background: Elevated blood concentrations of troponin proteins or brain natriuretic peptide (BNP) worsen the prognosis of patients with pulmonary embolism (PE). Novel biomarkers that reflect mechanisms of right ventricle (RV) damage from PE may provide additional prognostic value. We compare the prognostic use of BNP, troponin I, D-dimer, monocyte chemoattractant protein-1, matrix metalloproteinase, myeloperoxidase, C-reactive protein, and caspase 3 as biomarkers of RV damage and adverse outcomes in submassive PE.
Methods: This article used a prospective cohort study of normotensive (systolic blood pressure always >100 mm Hg) patients with computed tomographic angiography-diagnosed PE. All patients underwent echocardiography and phlebotomy at diagnosis, and survivors had another echocardiography 6 months later. We tested each biomarker for prognostic significance, requiring a lower limit 95% CI >0.50 for the area under the receiver operating characteristic curve (AUROC) with a reference standard positive of RV hypokinesis on either echocardiogram. Biomarkers with prognostic significance were dichotomized at the concentration that yielded highest likelihood ratio positive and mortality rates compared (Fisher exact test).
Results: We enrolled 152 patients with complete data. Thirty-seven (24%, 95% CI 18%-32%) had RV hypokinesis. Only BNP and troponin had significant AUROC values as follows: 0.71 (95% CI 0.60-0.81) and 0.71 (95% CI 0.62-0.82), respectively. Overall mortality was 13/153 (8.5%); mortality rate for BNP >100 versus < or =100 pg/mL was 23% versus 3% (P = .003), respectively. Mortality rate for troponin I >0.1 versus < or =0.1 ng/mL was 13% versus 6% (P = .205), respectively.
Conclusions: Of 8 mechanistically plausible biomarkers, only BNP and troponin I had significant prognostic use with BNP having an advantage for predicting mortality.