Home > Cardiology > ISTH 2020 > What’s New in Venous Thromboembolism > Less diagnostic delay in CTEPH diagnosis with novel algorithm

Less diagnostic delay in CTEPH diagnosis with novel algorithm

Presented by
Dr Gudula Boon, Leiden University Medical Center, the Netherlands
ISTH 2020
In the prospective, international InSHAPE II study, a non-invasive strategy for early identification of chronic thromboembolic pulmonary hypertension (CTEPH) after acute pulmonary embolism (PE) proved both accurate and cost-saving [1].

The diagnostic delay of CTEPH after acute PE is over 1 year and associated with increased mortality. Dr Gudula Boon (Leiden University Medical Center, the Netherlands) and her colleagues developed a non-invasive screening strategy comprising a 'CTEPH prediction score' and 'CTEPH rule-out criteria' aimed at diagnosing CTEPH earlier and limiting the number of required echocardiograms. “Six predictors [e.g. unprovoked PE, hypothyroidism, and diagnostic delay >2 weeks] have been identified that are highly probable for CTEPH and we included them in our score,” Dr Boon explained. The CTEPH rule-out criteria were only applied on low-risk patients with a presence of CTEPH-specific symptoms. According to these criteria, patients with at least 1 ECG criteria and/or abnormal NT-proBNP values were referred to echocardiography. Included were 424 patients from 6 hospitals in the Netherlands, Poland, and Belgium. Of these participants, 69% were judged low-risk and 31% high-risk. Of all participants, 48% were low-risk patients without CTEPH-specific symptoms, and 21% were low-risk patients with symptoms.

Successful identification of almost all CTEPH patients

The algorithm successfully ruled out 342 of 343 patients (see Figure). One missed case by the algorithm translates into a failure rate of 0.29%. “There was only 1 missed case who had persistent symptoms. However, this patient would also have been missed if echocardiography had been performed initially,” Dr Boon explained. With the algorithm, CTEPH was diagnosed within 4 months after the index PE diagnosis, which is less diagnostic delay than the average. In addition, echocardiography was avoided in 81% of patients.

Figure: CTEPH screening algorithm applied at 3 months after diagnosis and 2-year follow-up results [1]

CTEPH, chronic thromboembolic pulmonary hypertension; ECG, electrocardiography; NT-proBNP, N-terminal pro-brain natriuretic peptide; PE, pulmonary embolism; PH, pulmonary hypertension; RHC, right heart catheterisation; RV, right ventricular.  

1          Boon G, et al. OC.10.3, ISTH Virtual Congress 2020, 12-14 July.



Posted on