Pulmonary arteriovenous malformations (PAVMs) larger than 4mm in size are estimated to affect 38 per 100,000 individuals [95% confidence intervals 18-76]. They provide an anatomical right-to-left shunt such that each heartbeat, a proportion of the cardiac output bypasses the pulmonary capillary bed, preventing essential processing functions such as gas exchange and filtration of blood-borne emboli. Although large cohort series were published in earlier decades, more recent data series have been scant. To support modern educational platforms, here we report features of 1149 consecutive patients with imaging-proven PAVMs, reviewed at a single UK centre between 1984-2026, including 813 (71%) with clinical and/or genetically confirmed hereditary haemorrhagic telangiectasia (HHT). The median age was 47y, and 735 (64%) were female. We report 4348 oxygen saturation measurements at presentation and follow-up, and 810 pulmonary artery pressure (PAP) measurements made at angiography prior to treatment of PAVMs by embolisation. Together, these confirm that there is no risk of hypoxic pulmonary hypertension, with PAP measurements higher in patients with higher SaO2. Massive haemoptysis or haemothorax occurred in 18 patients [0.009, 0.023], of which 7/18 [95% CI 0.01, 0.64] events were pregnancy-associated. Ischaemic strokes affected 125 patients [0.09, 0.13], brain abscess 107 patients [0.08, 0.11] patients, and haemorrhagic strokes 29 patients [0.02, 0.03] patients. These data will inform design of future work to evaluate aetiologies, associations and implications for clinical practice.

The authors have declared no competing interest.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0088812

The National Institute for Health Research (NIHR) Imperial Biomedical Research Centre (NIHR203323); HHT charitable donations, and received specific funding from the NIHR Imperial BRC Digital Health Theme pilot project scheme

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Ethical approval for the prospective study was provided by the Hammersmith and Queen Charlottes & Chelsea Research Ethics Committee (REC ref. 2000/5764: Hammersmith Hospital patients with pulmonary arteriovenous malformations (PAVMs) and hereditary haemorrhagic telangiectasia) and remains valid. The research database was given favourable ethics approval by the South West - Central Bristol Research Ethics Committee (reference 21/SW/0120; IRAS project ID 282093).

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