Case 1: A 25 years old male patient was diagnosed with PAH after a sudden syncope in April 20th, 2017. His RHC data showed: mPAP 49mmHg, PAWP 11mmHg, PVR 9.89WU, CO 3.84 l/min and AVRT (-). CTPA found multiple distal PAM (pulmonary arteriovenous fistulae ) with alveolar bleeding. He got poor response to tadalafil and ambrisentan, and had progressive dyspnea, intermittent hemoptysis and chest pain. His second RHC(2019) showed worsened hemodynamics (mPAP 69mmHg, PAWP 1mmHg, PVR 26.97WU, CO 2.52 l/min). His gene analysis identified: BMPR2 gene c.1243G>A heterozygous missense mutation. He suffered from a fatal hemoptysis in March 31st, 2019.
Case 2: A female patient, 25 years old, she started repeated hemoptysis from June 2013,but got PAH diagnosis in February 2019. Her RHC showed: mPAP 78mmHg, PAWP 9mmHg, PVR 22.55WU, CO 3.06 l/min and AVRT (-). CTPA found multiple PAM. Pulmonary arteriography showed multiple aneurysm. Gene detection identified BMPR2 gene c.1305_1307delTTTinsG heterozygous frameshift mutation. She got poor results from ambrisentan and treprostinil and had a fatal hemoptysis in August 24th 2019.
Discussion: PAH is featured with loss and obstructive remodelling of the pulmonary vascular bed, which usually leads to peripheral pulmonary vascular sparseness. While the distal PAM were found in both of these 2 patients, which were different from common cases of PAH. They shared the similar manifestation: young age, serve hemodynamic dysfunction, poor response to vasodilator (target treatments), refractory and fatal hemoptysis. Gene sequencing identified BMPR2 gene mutation in these patients, which suggested possible pathogenesis for them. In conclusion, distal PAM related with fatal hemoptysis, which suggest poor prognosis in PAH patients.