Medical Therapy for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is pulmonary hypertension (PH) secondary to chronic emboli, obstructing the pulmonary arteries. This results in increased pulmonary vascular resistance and right ventricular failure. CTEPH is the only form of PH that is potentially curable, through a surgical procedure that removes the chronic emboli: pulmonary thromboendarterectomy (PTE). The first step in managing patients diagnosed with CTEPH is to determine if they are operable. The use of medical therapy should never delay referral for surgery, which should be done at a specialized center with expertise in CTEPH. Since a significant proportion of CTEPH patients are not surgical candidates, or are among the 10% to 15% of patients that have persistent or recurrent PH after surgery, there is a need for effective medical therapy. The use of several pulmonary arterial hypertension (PAH)-targeted agents have been studied, mostly in small uncontrolled trials. A recent Phase 3 clinical trial found riociguat, a stimulator of soluble guanylate cyclase (sGC), to be effective for inoperable CTEPH.