Abstract Background Mechanical interventions including balloon pulmonary angioplasty (BPA) are crucial for managing patients with chronic thromboembolic pulmonary hypertension (CTEPH). The diffusing capacity of the lungs for carbon monoxide (DLCO) of CTEPH patient has been reported to be associated with microvasculopathy, and patients with decreased DLCO showed a poor treatment response to BPA. Although it is anticipated that the untreated duration of CTEPH may affect the extent of microvasculopathy, it remains unclear whether a delay in initiating treatment from the onset of symptoms affects residual pulmonary hypertension after mechanical treatment. Purpose To explore the major determinants of residual pulmonary hypertension after BPA in patients with CTEPH. Methods In this single center, retrospective study, we studied patients newly diagnosed with CTEPH who underwent BPA between 2013 and 2023, excluding those with a history of pulmonary endarterectomy and patients classified as WHO functional class IV. Logistic regression analysis was performed to evaluate whether age, sex, %DLCO, mean pulmonary arterial pressure (mPAP), and a delay of more than one year from symptom onset to the initial BPA were predictors of residual pulmonary hypertension after BPA (mPAP ≥ 25 mmHg). Results Among 267 patients (mean age 65 years, 20% male), 31 (12%) exhibited residual pulmonary hypertension. The average number of BPA sessions per patient was 5, and no BPA-related deaths were observed. Multivariate analysis revealed that male sex (odds ratio 5.7 2.2–14.9, p 0.001), %DLCO (odds ratio 0.95 0.93–0.98, p 0.001), and a delay of more than one year from symptom onset to the initial BPA (odds ratio 3.3 1.4–8.2, p = 0.008) were independent predictors of residual pulmonary hypertension. Conclusion A delay of more than one year from symptom onset to the initial BPA, decreased DLCO, and male sex were independent predictors for residual pulmonary hypertension after BPA. The findings from this study suggest that early intervention following symptom onset is desirable to mitigate residual pulmonary hypertension.
Kuronuma et al. (Sat,) studied this question.