Abstract
Introduction: Current guidelines recommend against screening for chronic thromboembolic pulmonary hypertension (CTEPH) after acute pulmonary embolism (PE) due to the lack of a proven cost-effective diagnostic tool, despite the mean diagnostic delay of CTEPH diagnosis of over 1 year in current practice.
Methods: We studied 3 large cohorts of consecutive PE patients who were systematically evaluated for the presence of CTEPH after a median of 1.5 years following PE diagnosis. Additional diagnostic tests including right heart catheterisation were applied to those patients with suspected PH on echo. A clinical prediction score for CTEPH was derived based on logistic regression of relevant clinical variables at the time of the PE diagnosis, and validated by bootstrap analysis.
Results: Of the 772 patients 22 (2.8%) were diagnosed with CTEPH. Reperfusion therapy (-3 points, p=0.003), diabetes mellitus (-3 points, p=0.004), right ventricular dysfunction on CT or echocardiography (+2 points, p=0.003), symptom onset >2 weeks before PE diagnosis (+3 points, p<0.001), hypothyroidism (+3 points, p=0.002) and unprovoked PE (+6 points, p=0.011) independently predicted CTEPH. The area under the ROC curve (AUC) of the score combining these 6 variables was 0.89 (95%CI 0.84-0.94). Bootstrap internal validation confirmed this AUC. A total of 27% of patients were categorized to high risk category (CTEPH incidence 10%, 95%CI 6.5-15%) and 73% to low risk category (CTEPH incidence 0.38%, 95%CI 0-1.5%).
Conclusion: The newly derived 'CTEPH prediction score' allows for the identification of PE patients with high risk of CTEPH. If externally validated, the score may guide targeting CTEPH screening to high risk PE patients.
- Copyright ©ERS 2015