Radiation Following Percutaneous Balloon Aortic Valvuloplasty to Prevent Restenosis (RADAR Pilot Trial)

Objectives: We wished to determine the feasibility and early safety of external beam radiation therapy (EBRT) used following balloon aortic valvuloplasty (BAV) to prevent restenosis.

Background: BAV for calcific aortic stenosis (AS) has been largely abandoned because of high restenosis rates, i.e., > 80% at 1 year. Radiation therapy is useful in preventing restenosis following vascular interventions and treating other benign noncardiovascular disorders.

Methods: We conducted a 20-patient, pilot study evaluating EBRT to prevent restenosis following BAV in elderly patients with calcific AS. Total doses ranging from 12-18 Gy were delivered in fractions over a 3-5 day post-op period to the aortic valve. Echocardiography was performed pre and 2 days post-op, 1, 6, and 12 months following BAV.

Results: One-year follow-up is completed (age 89 +/- 4). There were no complications related to EBRT. Eight patients died prior to 1 year; 5 of 10 (50%) in the low-dose (12 Gy) group and 3 of 10 (30%) in the high-dose (15-18 Gy) group. None of these 8 patients had restenosis, i.e., > 50% loss of the initial AVA gain, and only three deaths were cardiac in origin. One patient underwent aortic valve replacement and none repeated BAV. By 1 year, 3 of the initial 10 (30%) in the low-dose group and 1 of 9 (11%) in the high-dose group demonstrated restenosis (21% overall).

Conclusions: EBRT following BAV in elderly patients with AS is feasible, free of early complications, and holds promise in reducing the 1 year restenosis rate in a dose-dependent fashion.