Pulmonary Hypertension in a Large Cohort with Hereditary Hemorrhagic Telangiectasia

Background: Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder characterized by arteriovenous malformations in the brain, liver, and lungs. Pulmonary hypertension (PH) is increasingly recognized as a severe complication of HHT. However, there are no studies describing the prevalence of PH in HHT compared to HHT-negative controls. Objective: To assess the estimated prevalence of PH in patients with HHT compared to HHT-negative controls. Methods: All consecutive subjects screened for HHT with available genetic testing and echocardiography-based peak tricuspid regurgitation velocity (TRV) measurement were included. Increased-probability PH was defined as a TRV >2.8 m/s. Results: In 578 subjects, both echocardiography and genetic testing were available. A reliable TRV was measured in 383 (66.3%), of whom 127 had HHT type 1 (HHT1), 150 had HHT type 2 (HHT2), and 106 were HHT-negative controls, with a mean TRV of 2.3 ± 0.4, 2.4 ± 0.5, and 2.2 ± 0.3 m/s, respectively (p = 0.008 and p < 0.001 vs. controls). Increased-probability PH was found in 42 subjects (8.7% in HHT1, 18.0% in HHT2, and 3.8% in HHT-negative controls). HHT2 and hepatic arteriovenous malformations (HAVMs) were the most important predictors for increased-probability PH (odds ratio 5.6, p = 0.002, and odds ratio 11.3, p < 0.001, respectively). Heritable pulmonary arterial hypertension (HPAH) was diagnosed in 2 patients (0.7%) and only found in HHT2 (1.3%). Conclusion: The estimated prevalence of PH is higher in HHT patients compared to HHT-negative controls. This increase is especially present in HHT2 and mainly associated with the presence of HAVMs. HPAH appears to be rare in HHT patients and was only diagnosed in HHT2.