Diagnostic Yield of Rescreening Adults for Pulmonary Arteriovenous Malformations

To determine the yield of rescreening adult hereditary hemorrhagic telangiectasia (HHT) patients with initial negative screening CT for pulmonary arteriovenous malformations (PAVMs).

Patients with a definite diagnosis of HHT were identified in the University of Toronto, Université de Montréal, and Mayo Clinic HHT databases. Inclusion criteria were: (i) definite diagnosis of HHT; (ii) initial negative PAVM screening based on bubble echocardiography and/or chest CT; and (iii) minimum 2-year imaging follow-up. A positive rescreen was defined as a newly detected PAVM on follow-up CT. Frequency of new PAVMs was calculated at 3 ± 1 years, 5 ± 1 years, 7-9 years, and ≥10 years. The primary endpoint was the rate of new PAVMs at 5 ± 1 years.

One hundred seventy-two patients (mean age, 49.6 ± 16.7 years; 59% female) were followed for a median of 7 years. Nine patients (5.2%) had newly detected PAVMs. At the 3-, 5-, 7-, and ≥10-year time points, the cumulative rate of newly detected PAVMs was 1.8% (3/166), 5.0% (7/140), 8.8% (8/91), and 13.8% (9/65), respectively. Median feeding artery diameter was 1.3 mm. One patient had a feeding artery larger than 3 mm discovered after 6 years and was treated with embolization. The overall rate of newly detected PAVMs was 0.7%/patient-year.

There is a definite but low rate of newly detected PAVMs in HHT patients with initial negative screening studies. No new treatable PAVMs were identified at the 5-year mark, although 1 treatable case was identified after 6 years. These findings suggest that a longer screening interval may be warranted.