Drug-coated balloon angioplasty may be effective for infrapopliteal disease

In patients with critical limb ischaemia (CLI) due to chronic total occlusions in the infrapopliteal region, drug-coated balloon (DCB) angioplasty was associated with a lower rate of late lumen loss compared with the standard balloon angioplasty – percutaneous transluminal angioplasty (PTA), according to the results of the IN.PACT below-the-knee (BTK) feasibility study presented at TCT 2020.

“DCB demonstrated effectiveness through 9 months vs PTA in a complex population,” said Dr Antonio Micari from the University of Messina, Italy, who presented the findings.

The study comprised 50 CLI patients (mean age 71 years, 78 percent male) with chronic total occlusions in the infrapopliteal arteries above the ankle (Rutherford class 4/5; single or multiple, with total lesion length ≥40 mm). Following successful vessel dilation (ie, ≤30 percent residual stenosis documented by angiographic visual estimate and functional duplex ultrasound assessment), participants were randomized 1:1 to receive either the IN.PACT 0.014 paclitaxel-coated DCB with a dose density of 3.5 μg/mm², or conventional PTA. [TCT 2020, Endovascular 1: LBCT/LBCS session]

Nine months following the index procedure, there was a significantly lower rate of subsegmental late lumen loss with DCB vs PTA (mean, 0.59 vs 1.26 mm; p=0.017). A similar but nonsignificant trend was seen in terms of classic late lumen loss (mean, 0.89 vs 1.31 mm; p=0.070).

It is important to note that there were similar baseline lesion lengths and calcifications in both the DCB and PTA arms (215.41 and 218.19 mm; p=0.806 [length] and 54.1 percent and 41.4 percent; p=0.410 [calcification]). “These were very long and calcified lesions … The subsegmental measurement [at 9 months] showed a difference in the burden of restenosis in the two groups,” said Micari.

In the subsegmental method, measurements are taken along the entire lesion length, allowing for better assessment of late lumen loss. Whereas in the classic method, the measurement is obtained only at a single point in the lesion, explained Micari. “[Though] more rigorous, [the subsegmental method] can provide more feedback on how lesions failed over time,” he pointed out.

Safety-wise, the DCB and PTA arms had similar rates of the composite* safety endpoint (91.3 percent vs 87.5 percent; p=1.00). The rates of all-cause death were low (4.3 percent vs 8.0 percent), as were the rates of thrombosis at the target lesion site (4.3 percent vs 4.2 percent; p=1.00 for both).

“We purposefully included the most challenging lesions to reflect real-world CLI patients,” noted Micari. However, as the trial was underpowered, definitive conclusions cannot be made as to the role of DCB angioplasty for infrapopliteal disease.

Nonetheless, Micari expressed the study team’s plan of following through the patients for up to 3 or even 5 years to evaluate the mid- and long-term effects. “For now, we are happy to show that even in a small population, we have a difference … We are definitely looking forward to a bigger trial; we will enrol more patients and do a randomized study to give more sense to this data.”

“[Moreover, our study] provides an opportunity to affect future BTK studies and treatment algorithms,” he added.