Risk stratification of elderly patients with acute pulmonary embolism

BACKGROUND: Combining high-sensitivity cardiac Troponin T (hs-cTnT), NT-pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) may improve risk stratification of patients with pulmonary embolism (PE) beyond the PESI risk score. METHODS: In the prospective multicentre SWITCO65+ study, we analysed 214 patients ≥ 65 years with a new submassive PE. Biomarkers and clinical information for the PESI risk score were ascertained within 1 day after diagnosis. Associations of hs-TnT, NT-proBNP, hs-CRP and the PESI risk score with the primary endpoint defined as 6-month mortality were assessed. The discriminative power of the PESI risk score and its combination with hs-cTnT, NT-proBNP and hs-CRP for 6-month mortality was compared using integrated discrimination improvement (IDI) index and net reclassification improvement (NRI). RESULTS: Compared with the lowest quartile, patients in the highest quartile had a higher risk of death during the first 6 months for hs-cTnT (adjusted HR 10.22; 95% CI 1.79-58.34; P = 0.009) and a trend for NT-proBNP (adjusted HR 4.3; 95% CI 0.9-20.41; P = 0.067) unlike hs-CRP (adjusted HR 1.97; 95% CI 0.48-8.05; P = 0.344). The PESI risk score (c-statistic 0.77 (95% CI 0.69-0.84) had the highest prognostic accuracy for 6-month mortality, outperforming hs-cTnT, NT-proBNP and hs-CRP (c-statistics of 0.72, 0.72, and 0.54), respectively. Combining all three biomarkers had no clinically relevant impact on risk stratification when added to the PESI risk score (IDI = 0.067; 95% CI 0.012-0.123; P = 0.018; NRI = 0.101 95% CI -0.099-0.302; P = 0.321). CONCLUSIONS: In elderly patients with PE, 6-month mortality can adequately be predicted by the PESI risk score alone.