JACC: Drug-eluting balloons may help PAD patients but jury is still out
Using drug-eluting balloons (DEBs) in the long infrapopliteal arteries could be a safe and effective approach, according to a study published Aug. 30 in the Journal of the American College of Cardiology. German researchers reported that the restenosis rate at three months decreased more than 60 percent when compared with use of uncoated balloons in this area. However, an accompanying editorial urged that these positive findings are still in their infancy and that more clinical trials will be necessary to prove their worth.

“Percutaneous transluminal angioplasty (PTA) is increasingly used to treat infrapopliteal arterial disease,” Andrej Schmidt, MD, of the Park Hospital Leipzig in Leipzig, Germany, and colleagues wrote. “However, the high restenosis rate is problematic, and repeat interventions may be required in a significant proportion of patients to achieve clinical goals.”

Schmidt and colleagues evaluated whether DEBs could lower the restenosis rate in 104 patients with either critical limb ischemia or severe claudication and below-the-knee lesions. The patients were treated with a paclitaxel-eluting balloon (In.Pact Amphirion, Medtronic) and were enrolled between January 2009 and February 2010 at the Park Hospital. In the 104 patients, 109 limbs were treated for critical limb ischemia (82.6 percent) or severe claudication (17.4 percent). Mean infrapopliteal lesion length was 176 mm.

The researchers performed angiography at three months to detect restenosis. Schmidt and colleagues reported that 84 arteries at three months showed a restenosis rate of 27.4 percent (19.1 percent of patients had restenosis of more than 50 percent and 8.3 percent were totally occluded). At three-month follow-up, 94 patients remained. Of these, 75.8 percent of patients saw a clinical improvement in treated limbs, 22.2 percent remained unchanged and 2 percent were clinically worse.

During a subgroup analysis of 74 patients angiographically examined at three months, 61 of 84 arteries were free of restenosis. The researchers noted that a restenosis of 50 percent or more was found in 27.4 percent of these patients. After the midterm clinical follow-up (mean follow-up of 378 days) 86 patients with 91 treated limbs were evaluated. Of the remaining patients, 91.2 percent saw clinical improvement and complete wound healing occurred in 74.2 percent of patients.

“The three-month restenosis rate of 27 percent after treatment with DEB represents a dramatic reduction for restenosis of 61 percent from the 69 percent seen in the series using uncoated balloons,” the authors wrote. While Schmidt and colleagues noted that the study population was too small to perform a meaningful subanalysis, they concluded that distal lesions seemed to perform worst.

Additionally, the authors noted, “We found nothing to indicate the use of DEBs BTK to be unsafe,” and said that the 4.4 percent amputation rate was acceptable for critical limb ischemia patients.

The use of DEBs may be favorable due to the low rate of target lesion revascularization (TLR) found in the study—17.3 percent. The TLR rate when uncoated balloons were used was 50 percent. “It is with regard to TLR that the use of DEBs has most potential to improve clinical outcomes compared with standard balloons,” Schmidt and colleagues noted.

While the authors said that costs are likely to play a role in the increased use of DEB, the reduced number of reinterventions when DEBs are used may make the strategy a viable alternative.The researchers concluded that a future randomized controlled trial will be necessary to confirm whether DEBs are superior to balloon angioplasty in critical limb ischemia patients with peripheral artery disease.

In an accompanying editorial, Michael R. Jaff, DO, of Massachusetts General Hospital in Boston, wrote that while Schmidt et al’s results may be promising, he called the single-center nature of the study limiting. “The concepts describing the mechanisms and impact of drug delivery by an angioplasty balloon catheter are still in their infancy, and this finding raises some concern,” Jaff noted. He added that future research must address the impact of this therapy on arterial wall integrity.

Because these technologies are more expensive than uncoated balloon catheters, “if the clinical indication for use of drug-coated balloons is limb salvage via healing of ischemic ulcerations, it seems that despite the marked improvement in vessel patency, there is no clear advantage of the more expensive technology over PTA alone,” Jaff wrote. Particularly in the era of healthcare reform, a cost-effectiveness analysis will need to be performed to understand whether this new technology will be advantageous in terms of cost as well as outcomes, he wrote.

Jaff concluded that the mortality rate was of some concern. The 16.3 percent mortality rate among 104 patients was significantly higher than that for women with breast cancer (24 per 100,000 women/year), Jaff noted.

“For any endovascular technology to represent a true breakthrough, not only must the treatment promote improvement in functional capacity and limb salvage, but also strategies to prolong overall survival must be even more effective. Without the latter, the relevance of patent limb arteries wanes,” Jaff concluded.