Clinical characteristics of pulmonary hypertension associated with hereditary hemorrhagic telangiectasia treated with bevacizumab: a single-center case series.

BACKGROUND: Pulmonary hypertension (PH) is a severe complication of hereditary hemorrhagic telangiectasia (HHT). The experience with bevacizumab in HHT-PH is limited. Therefore, the aim was to provide our single-center experience with the use of bevacizumab in patients with HHT-PH. METHODS: The clinical data of HHT-PH patients treated with bevacizumab were retrospectively reviewed between September 2021 and June 2024 at Beijing Anzhen Hospital, Capital Medical University. To describe the clinical features of these patients, we recruited pulmonary arterial hypertension (PAH) patients and PH associated with left heart diseases (PH-LHD) patients, matched for age and gender. The symptoms, underlying diseases, medication history, laboratory test results, treatments, and therapeutic responses were investigated retrospectively in all patients. RESULTS: In total, six cases of HHT-PH that were treated with bevacizumab, of which only five received follow-up after completing the 3-month induction therapy. Compared with PAH and PH-LHD patients, HHT-PH patients were characterized by high cardiac index (CI) [HHT-PH vs. PAH vs. PH-LHD: 6.10 (3.77, 7.60) vs. 2.37 (1.92, 3.03) vs. 2.38 (1.91, 2.63) L/min/m2, P=0.001] in conjunction with low systemic vascular resistance [740.93±333.06 vs. 1,836.07±673.64 vs. 1,667.78±453.84 dyn·s·cm-5, P=0.001] and PVR [189.94 (54.46, 289.89) vs. 886.70 (705.18, 1278.68) vs. 229.48 (179.15, 416.60) dyn·s·cm-5, P=0.002]. All the HHT-PH patients experienced significant improvements in symptoms (World Health Organization functional class), hemoglobin, brain natriuretic peptide levels and tricuspid annular plane systolic excursion/systolic pulmonary arterial pressure after the induction therapy with bevacizumab. Of note, two of the five patients had a baseline CI <4 L/min/m2, yet still experienced clinically meaningful improvement after the bevacizumab induction therapy. Four out of five patients experienced improvements in hemodynamics and 6-minute walking distance after the induction therapy. CONCLUSIONS: Our study found that the hemodynamic profile of HHT-PH patients treated with bevacizumab differed significantly from that of PAH and PH-LHD. There might be patients with a CI below 4 L/min/m2 who were still in a high-output state and could benefit from bevacizumab treatment in clinical practice.