Frequency and characterization of CTEPH and CTEPD according to the mPAP threshold > 20 mm Hg: Retrospective analysis from data of a prospective PE aftercare program

Abstract

Background: The influence of the new pulmonary hypertension (PH) definition on the incidence of chronic thromboembolic PH (CTEPH) is unclear. The incidence of chronic thromboembolic pulmonary disease without PH (CTEPD) is unknown.

Objectives: To determine the frequency of CTEPH and CTEPD using the new mPAP cut-off >20 mmHg for PH in patients who have suffered an incidence of pulmonary embolism (PE) and were recruited into an aftercare program.

Methods: In a prospective two-year observational study based on telephone calls, echocardiography and cardiopulmonary exercise tests, patients with findings suspicious for PH received an invasive work-up. Data from right heart catheterization were used to identify patients with or without CTEPH/CTEPD.

Results: Two years after acute PE (n = 400) we found an incidence of 5.25% for CTEPH (n = 21) and 5.75% for CTEPD (n = 23) according to the new mPAP threshold >20 mmHg. Five of 21 patients with CTEPH and 13 of 23 patients with CTEPD showed no signs of PH in echocardiography. CTEPH and CTEPD subjects showed a reduced VO₂ peak and work rate in cardiopulmonary exercise testing (CPET). The capillary end-tidal CO₂ gradient was comparably elevated in CTEPH and CTEPD, but it was normal in the Non-CTEPD-Non-PH group. According to the PH definition provided by the former guidelines, only 17 (4.25%) patients have been diagnosed with CTEPH and 27 individuals (6.75%) were classified having CTEPD.

Conclusions: Using mPAP >20 mmHg for diagnosis of CTEPH leads to an increase of 23.5% of CTEPH diagnosis. CPET may help to detect CTEPD and CTEPH.

Keywords: Cardiopulmonary exercise testing; Chronic thromboembolic pulmonary disease; Chronic thromboembolic pulmonary hypertension; Functional limitation; Pulmonary embolism; Right heart catheterization.