Primary outcomes and mechanism of action of intravascular lithotripsy in calcified, femoropopliteal lesions: Results of Disrupt PAD II

Objective: DISRUPT PAD II was designed to evaluate the safety and performance of intravascular lithotripsy (IVL), a novel approach using pulsatile sonic pressure waves, to modify intimal and medial calcium in stenotic peripheral arteries. Background: Vascular calcification restricts vessel expansion, increases the risk of vascular complications, and may impair the effect of anti-proliferative therapy. Methods: Disrupt PAD II was a non-randomized, multi-center study that enrolled 60 subjects with complex, calcified peripheral arterial stenosis at eight sites. Patients were treated with IVL and followed to 12-months. The primary safety endpoint was major adverse events (MAE) through 30 days. The primary effectiveness endpoint was patency at 12 months as adjudicated by duplex ultrasonography (DUS). Key secondary endpoints included acute procedure success, freedom from re-intervention, and functional outcomes. Results: Between June 2015 and December 2015, subjects with moderate or severe calcified arterial lesions were enrolled. The final residual stenosis was 24.2%, with an average acute gain of 3.0 mm. The 30-day MAE rate was 1.7% with one grade D dissection that resolved following stent placement. Primary patency at 12 months was 54.5%, and clinically driven TLR at 12 months was 20.7%. Optimal IVL technique defined by correct balloon sizing and avoiding therapeutic miss, improved 12-month primary patency and TLR outcomes to 62.9% and 8.6%, respectively. Conclusions: IVL demonstrated compelling safety with minimal vessel injury, and minimal use of adjunctive stents in a complex, difficult to treat population.