Background: Our aim was to construct a diagnostic model for ruling out chronic thromboembolic pulmonary hypertension (CTEPH) in symptomatic patients after acute pulmonary embolism (PE) that is based on simple, non-invasive tests.
Methods: Plasma levels of various CTEPH associated biomarkers and conventional ECG criteria for right ventricular pressure overload were assessed in 82 consecutive patients with confirmed CTEPH and 160 consecutive patients with a history of PE who were suspected to have CTEPH, but in whom this disease was ruled out.
Results: ECG criteria of right ventricular hypertrophy were detected more frequently in patients with CTEPH (77%) than in the patients without CTEPH (11%, Odds ratio 26, 95% confidence interval [CI] 13-53). Also, clotting factor FVIII activity and the levels of N-terminal-pro-brain-type natriuretic peptide (NT-pro-BNP), Growth Differentiation Factor-15, C-reactive protein and urate, but not D-dimer level, were higher in patients with CTEPH. A diagnostic model including ECG criteria and NT-pro-BNP levels had a sensitivity of 94% (95% CI 86-98%) and a specificity of 65% (95% CI 56-72%). The area under the receiver-operator-characteristic curve was 0.80 (95% CI 0.74-0.85) for the diagnosis of CTEPH. Even with high disease prevalences of up to 10%, the negative predictive value of this model proved to be very high (99%, 95% CI 97-100%).
Conclusions: Ruling out CTEPH in patients after acute PE seems to be safe without additional diagnostic testing in absence of ECG criteria indicative of right ventricular hypertrophy and a normal NT-pro-BNP level.
Copyright © 2010 Elsevier Ltd. All rights reserved.