MOBILITY trial shows stent systems reduce adverse events and improve walking in patients with complex iliac artery lesions


Two types of stent systems are both effective in treating patients who have severe forms of peripheral artery disease, according to results of the MOBILITY trial presented by Michael R Jaff , Boston, USA, on 10 May as a late-breaking clinical trial at the Society for Cardiovascular Angiography and Interventions (SCAI) 2012 Scientific Sessions in Las Vegas, USA.

The study found patients with complex lesions who were treated with a balloon-expandable stent system, in which a balloon-tipped catheter is inflated to expand and place the stent, or a self-expanding stent system, which is made of flexible material designed to conform to challenging lesions, saw improvement in walking ability, while maintaining low rates of restenosis and major adverse events.

Traditionally, patients with iliac artery disease have been excluded from clinical trials if they have highly calcific lesions. However, these patients often are more representative of “real-world” patients treated by interventional cardiologists. The MOBILITY trial was designed to test the effectiveness of a self-expanding stent system and a balloon-expandable stent system in patients with intermittent claudication or critical limb ischaemia with even the most complex lesions.

A total of 304 patients with 384 lesions were enrolled in the multicentre trial. Of those, 151 patients were treated with the Absolute Pro Peripheral Self-Expanding Stent System (Abbott Vascular), while 153 were treated with the Omnilink Elite Peripheral Balloon-Expandable Stent System (Abbott Vascular). A high degree of calcification has been thought to result in failure of endovascular therapy, but that was not seen in the study. After nine months, the rate of major adverse events was 6.1% for patients treated with the Absolute Pro and 5.4% for patients treated with the Omnilink, significantly below the primary endpoint goal of 19.5% (p<0.0001). Walking ability significantly improved for both sets of patients, and restenosis rates were 8.4% for the Absolute Pro and 9.0% for the Omnilink, even though moderate to severe calcification was noted in 90% of all lesions treated.

“These results demonstrate that balloon-expandable and self-expandable stent systems are effective even in real-world patients. At nine months, we saw improvements in walking ability, while still maintaining low rates of restenosis and major adverse events,” said Jaff, medical director of the Vascular Ultrasound Core Laboratory at Massachusetts General Hospital, USA. “The study shows even patients with severe lesions can be successfully treated, helping restore their movement. After nine months, patients saw improvement in walking distance and speed, as well as ability to climb stairs.”