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

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.