Six-month interim analysis of the Legflow drug-eluting balloon for the treatment of femoropopliteal occlusions (LEG-DEB) registry indicates that “the use of a new generation paclitaxel drug-coated balloon… represents a safe and effective therapeutic strategy,” according to the study investigators. Writing in the International Journal of Cardiology, they note, “In this registry, as expected for this complex patient subset, the Legflow drug-coated balloon appears to be slightly less successful when compared to the outstanding performance achieved by drug-coated balloons in claudicating patients.”
The authors, led by Eugenio Stablie (University Federico II, Naples, Italy), write than plain balloon angioplasty can be a valuable therapeutic approach for lower limb atherosclerosis patients presenting with critical limb ischaemia or severe claudication, which may limit surgical treatment options. However, the long-term efficacy of plain balloon angioplasty is “hampered by the occurrence of restenosis of the treated arterial segment”. This problem is especially pronounced in critical limb ischaemia patients (Rutherford class >4) due to more systemic inflammation.
Early-generation drug-coated balloon randomised trials have produced encouraging results in preventing femoropopliteal restenosis following plain balloon angioplasty. However, the authors point out that these trials have mostly enrolled claudication (Rutherford class ≤4) patients, so do not provide any meaningful data for critical limb ischaemia patients. Further hampering clinical efficacy in challenging conditions, Stablile et al write, early drug-coated balloons “have several unsolved technical limitations such as inconsistent drug coating concentrations, significant drug loss prior to treatment, use of large paclitaxel particles which increases the risk of embolisation, and excessive initial balloon-artery drug transfer rates resulting in early drug-in-tissue concentrations which are too high.”
New-generation balloons have thus been developed in an attempt to address these issues. The multicentre, prospective LEG-DEB registry was designed to evaluate the six-month safety and efficacy of the Legflow paclitaxel-coated balloon (Cardionovum) in treating “real-world” femoropopliteal artery disease, including claudication and critical limb ischaemia patients. The Legflow balloon is “covered with a homogenous and stable surface coating using extremely small, non-visible paclitaxel particles, and which does not require the use of an extra drug-coated balloon protection and insertion tool,” Stabile and colleagues explain.
The registry enrolled 123 consecutive patients at four European institutions between January 2014 and June 2015. All patients underwent Legflow drug-coated balloon angioplasty treatment of the superficial femoral and/or popliteal artery. Of the treated patients, 79 (64.2%) were treated for claudication and 44 (35.8%) for critical limb ischaemia. Seventy-six patients (61.7%) were treated for de novo lesions (mean lesion length 95.1±57mm), 26 (21.1%) patients for restenosis (mean lesion length 96.1±32.1mm) and 21 (17.1%) for in-stent restenosis (mean lesion length 114.3±24.1mm).
The primary endpoint for six-month primary patency was defined as the absence of clinically-driven target lesion revascularisation and binary restenosis (>50%) assessed by angiography (or duplex ultrasonography if angiography was unavailable).
Stabile and colleagues report that all procedures were successful in terms of angiographic and clinical success, and that technical and procedural success was achieved in all patients. Two patients (1.6%) had died at six months, both from non-cardiovascular causes. Freedom from target lesion revascularisation was achieved in 88.6% (n=109/123) of all patients. Freedom from target lesion revascularisation was achieved in 93.6% (n=74/79) of claudication patients, and in 79.5% (35/44) of critical limb ischaemia patients.
Analysis by lesion characteristics found an 88.2% (n=67/76) freedom from target lesion revascularisation rate for patients with de novo lesions, and 80.8% (n=21/26) for those with restenosis. No target lesion revascularisation was observed in the 21 in-stent restenosis patients. The authors also note that lesion length did not affect target lesion revascularisation rates—lesion lengths of <100mm had a freedom from target lesion revascularisation rate of 88.9% (n=56/63) versus 90% (n=54/60) in lesion lengths >100mm. However, the presence of diabetes did affect target lesion revascularisation—diabetic patients had a rate of 86.7% (n=52/60) freedom from target lesion revascularisation versus 90.5% (n=57/63) for non-diabetics.
The LEG-DEB registry outcomes are the first to report the efficacy of a drug-coated balloon in critical limb ischaemia patients. Now, the “safe and effective” strategy will need to be confirmed in longer-term follow-up, conclude the authors.