Prevalence of Pulmonary Arteriovenous Malformations as Estimated by Low-Dose Thoracic CT Screening

Abstract

Background Pulmonary arteriovenous malformations (PAVMs) are rarely encountered in clinical practice. The prevalence of PAVMs associated with hereditary hemorrhagic telangiectasia (HHT) has been estimated based on the rate in the family members of HHT patients, but the prevalence of PAVMs in the general population remains unknown. Methods We retrospectively examined the prevalence and clinical characteristics of PAVMs as detected by a low-dose thoracic CT screening program for lung cancer at the Hitachi Medical Center and the Hitachi General Health Care Center in the northern part of Ibaraki Prefecture, Japan.Results From 2001 to 2007, we identified eight patients (seven females and one male) with PAVMs among 21,235 initial screening participants (the mean age of the patients with PAVMs and that of the screening participants was 60.6 years). The prevalence of PAVMs was estimated at 38 per 100,000 individuals [95% confidence interval (CI)=18-76]. The diameter of the PAVMs was a mean of 6.6 mm, and none of the lesions could be detected by chest X-ray. Females older than 60 years tended to have larger PAVMs than younger women did (p=0.06). Two patients (25%) were diagnosed with HHT. One patient had previously undergone surgery for a brain abscess. Conclusion PAVMs are more prevalent than previously reported, especially among females.

The UK prevalence of hereditary haemorrhagic telangiectasia and its association with sex, socioeconomic status and region of residence: a population-based study

“…One further limitation that complicates all studies of HHT prevalence at present is the likelihood of undiagnosed individuals with HHT at large in the community. This may explain the higher prevalence of PAVMs as defined by radiological criteria (and by inference, HHT) in patients who were participating in a recent Japanese CT screening program for lung cancer16 than we observed in our dataset which did not use this radiological definition of the disease. Diagnosis is often confounded by the heterogeneous clinical presentation of HHT due to its variable genetic penetrance and expressivity 17.…”

Cardiopulmonary Exercise Testing Demonstrates Maintenance of Exercise Capacity in Patients With Hypoxemia and Pulmonary Arteriovenous Malformations

“…oxygen consumption W Watts undiagnosed for decades until detection by incidental 2 or screening 1 studies. Insights into why PAVM patients differ to other hypoxemic respiratory patients are provided by exercise studies performed over 20 years ago.…”

British Thoracic Society Clinical Statement on Pulmonary Arteriovenous Malformations

“…PAVMs allow a proportion of the right ventricular stroke volume to bypass gas exchange, filtration and other functions of the pulmonary capillary bed. Limited prevalence data suggest that PAVMs may affect many as 1 in 2600 individuals (95% CIs 1 in 1315 to 1 in 5555) 5. The majority of PAVMs are due to hereditary haemorrhagic telangiectasia (HHT),6–9 but there is evidence for underappreciation of both PAVMs10 and HHT 11.…”