Catheter-Based Therapy for Inoperable Chronic Thromboembolic Pulmonary Hypertension

Interventional cardiologists have been innovators in treating all forms of vascular and valvular heart disease in the systemic circulation; however, the pulmonary circulation has not received the same degree of interest from our community. Recent advances in the diagnosis and management of pulmonary vascular diseases and multidisciplinary collaboration among pulmonologists, cardiologists, and surgeons have brought the interventional treatment of pulmonary vascular disease to the forefront. One area of particular interest is the interventional management of chronic thromboembolic pulmonary hypertension (CTEPH) in inoperable patients. CTEPH is a form of pulmonary hypertension that is characterized by a mean pulmonary artery pressure (mPAP) ≥25 mm Hg, a pulmonary artery occlusion pressure of <15 mm Hg, and the presence of partially or completely occlusive thrombi in the main, lobar, segmental, or subsegmental pulmonary arteries that are present after at least 3 months of effective anticoagulation.1 The incidence of CTEPH is estimated to be 1.6 to 7.9 cases per million, and ≈0.6% to 4.8% of individuals may develop CTEPH within 2 years of an acute pulmonary embolism.2,3 The true incidence of CTEPH is likely underestimated owing to the nonspecific nature of the associated symptoms. Patients typically present with exercise intolerance, fatigue, and exertional dyspnea and may also have chest discomfort, peripheral edema, light-headedness, or syncope.2,3At present, surgical pulmonary endarterectomy is the only established and curative therapy for CTEPH; all patients with CTEPH should be evaluated at expert centers to determine candidacy for surgery. Surgery decreases mortality with an estimated survival at 1, 2, and 3 years of 93%, 91%, and 89% in operated patients compared with 88%, 79%, and 70% in nonoperated patients.4 Despite the survival advantage offered by surgery, recent findings from international registries have revealed that ≤37% of patients with CTEPH are deemed inoperable owing to …