Chronic Thromboembolic Pulmonary Hypertension in Patients With Thoracic Outlet Syndrome-Association With Younger Age and More Distal Disease

We aimed to elucidate the potential role for thoracic outlet syndrome (TOS) and upper extremity deep venous thrombosis in the development of chronic thromboembolic pulmonary hypertension (CTEPH).

Charts from 64 consecutive patients with CTEPH who underwent pulmonary endarterectomy in Helsinki University Hospital between 2015 and 2023 were analysed for baseline characteristics, risk factors for thrombosis, treatments, and outcome at 1 year.

We found that seven patients with CTEPH (11%) had TOS with subclavian vein stenosis, impaired flow, and collaterals in provocation contrast venography. These patients with TOS CTEPH were younger (median 23 vs 59 years, p<0.001) and had more often distal (segmental 100% vs 38,6%, p<0.01) disease than other patients with CTEPH and had fewer risk factors for thrombosis (p<0.05). Functional class, N-terminal pro-B-type natriuretic peptide (NT-proBNP), 6-minute walk test and pulmonary vascular resistance (PVR) at baseline were similar. At 1 year postoperatively, there was a similar improvement in PVR (-45% vs -56%), NT-proBNP (-70.0% vs -71.8%), and functional class (improvement in 85.7% vs 91.5%) whereas 6-minute walk test increased more (247 vs 100 m, p<0.05) in patients with TOS. Patients with TOS were more often treated with balloon pulmonary angioplasty postoperatively (57.0 vs 10.5%, p<0.01). Treatment with pulmonary vasodilators did not differ significantly (42.9% vs 15.1%). TOS was later treated with thoracoscopic first-rib resection in three patients (43%).

CTEPH with upper extremity deep venous thrombosis and TOS represents a unique subgroup of patients who benefit from interventional therapies.