The following is a summary of “Frequency and characterization of CTEPH and CTEPD according to the mPAP threshold > 20 mm Hg: Retrospective analysis from prospective PE aftercare program data,” published in the APRIL 2023 issue of Pulmonology by Held, et al.

The impact of the new definition of pulmonary hypertension (PH) on the prevalence of chronic thromboembolic PH (CTEPH) is uncertain, and the incidence of chronic thromboembolic pulmonary disease without PH (CTEPD) is unknown. Therefore, for a study, researchers sought to determine the occurrence of CTEPH and CTEPD in patients who experienced pulmonary embolism (PE) and participated in an aftercare program, using the new mPAP threshold of >20 mmHg for diagnosing PH. 

In a prospective two-year observational study that included telephone follow-up, echocardiography, and cardiopulmonary exercise testing, patients who exhibited symptoms suggestive of PH underwent an invasive examination. In addition, patients with and without CTEPH/CTEPD were identified using data from right heart catheterization.

The results showed a 5.25% incidence of CTEPH (n = 21) and a 5.75% incidence of CTEPD (n = 23) two years after acute PE (n = 400), according to the new mPAP threshold of >20 mmHg. Of the patients with CTEPH, 5 out of 21 did not present any signs of PH in echocardiography, and 13 out of 23 patients with CTEPD also did not show any signs of PH. CTEPH and CTEPD subjects demonstrated reduced VO₂ peak and work rate during cardiopulmonary exercise testing (CPET), and the capillary end-tidal CO2 gradient was comparably elevated in CTEPH and CTEPD but normal in the Non-CTEPD-Non-PH group. Using the former guidelines’ PH definition, only 17 (4.25%) patients were diagnosed with CTEPH, and 27 individuals (6.75%) were identified as having CTEPD.

In conclusion, using mPAP >20 mmHg for diagnosing CTEPH resulted in a 23.5% increase in CTEPH diagnosis. CPET may aid in detecting CTEPD and CTEPH.

Reference: resmedjournal.com/article/S0954-6111(23)00065-3/fulltext