Association between the prognosis and comorbidity of active cancer in chronic thromboembolic pulmonary hypertension.

Background: Prognosis of chronic thromboembolic pulmonary hypertension (CTEPH) has improved after the availability of balloon pulmonary angioplasty (BPA) and approved drugs. However, the clinical effects of cancer, which is one of the associated medical conditions of CTEPH, remain unclear. We aimed to investigate prognosis in patients with CTEPH and comorbid cancer.

Methods: Between January 2011 and December 2022, data of 264 consecutive patients with CTEPH who were treated with pulmonary endarterectomy, BPA, or medical therapy were retrospectively analyzed. The patients were allocated, based on the comorbidity of cancer as of December 2022, into the cancer (n = 47) and non-cancer (n = 217) groups. In the cancer group, active and non-active cancers were identified in 30 (64%) and 17 (36%) patients, respectively.

Results: The baseline characteristics, hemodynamics, and treatments were similar between the groups. More than half of the cancer were diagnosed within two years before or after CTEPH diagnosis. Twenty-seven patients died during the study period. Among them, 13 (48%) and 7 (26%) died of cancer and right heart failure, respectively. The 5-year survival rate was lower in the cancer group than in the non-cancer group (67.8% vs. 94.5%, p < 0.001). In the active cancer group, the 5-year survival rate was also lower than that in the non-active cancer and non-cancer groups (52.0% vs. 99.5%, p < 0.001 and 52.0% vs. 92.3%, p < 0.001, respectively). Multivariate Cox hazard analysis revealed that hemodialysis (p < 0.001) and cancer (p < 0.001) were independently associated with poor survival.

Conclusion: Patients with CTEPH rarely die of right heart failure, even if hemodynamically severe at diagnosis in the modern management era. However, patients with CTEPH frequently have comorbid cancer, which may be a strong prognostic factor.