PARIS – A proprietary drug-coated percutaneous angioplasty balloon has achieved unprecedented clinical success in treating long lesions in the superficial femoral arteries.
“The 360-day primary patency rate of 91.1% and clinically driven target lesion revascularization rate of 6% are unmatched for this complex patient subgroup,” Dr. Dierk Scheinert declared in presenting the results of the IN.PACT Global Study Long Lesion Imaging Cohort at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.
Dr. Dierk Scheinert
The 157 patients who comprise the long lesion cohort are among 1,538 patients with various forms of complex peripheral arterial disease being treated at 64 sites on four continents under the IN.PACT Global Clinical Study, which focuses on the use of Medtronic’s Admiral paclitaxel-coated balloon for percutaneous transluminal angioplasty. Upon balloon inflation, the paclitaxel binds to the vessel wall, penetrating deep into the adventitia in order to interfere with smooth muscle cell proliferation and neointimal hyperplasia. The drug remains in the vessel wall at therapeutic levels for up to 6 months.
The Food and Drug Administration approved the balloon for lesions up to 18 cm in length in native superficial femoral or popliteal arteries. Dr. Scheinert presented a study that sought to broaden that indication: The average lesion length in the 157 participants was 26.4 cm.
The majority of the target lesions, 83%, were de novo, 60% were total occlusions, and 72% featured calcification. These were patients with substantial comorbidities: 41% had diabetes, 88% hypertension, 52% coronary heart disease, 77% dyslipidemia, and 34% were current smokers, noted Dr. Scheinert, professor and chairman of the department of vascular medicine and angiology at the University of Leipzig (Germany).
The mean diameter of the target stenosis was 90% predilatation and 39% afterwards. Provisional stents were implanted in 33% of the 100 patients with lesion lengths of 15-25 cm and 53% in those with lesions longer than 25 cm.
The 12-month primary patency rate, defined as freedom from clinically driven target lesion revascularization and restenosis as determined by a central core lab, varied by lesion length: 97.7% for 15- to 25-cm-long lesions compared with 79.2% for longer ones.
The major adverse event rate – a composite of all-cause mortality, major target limb amputation, clinically driven target vessel revascularization, or thrombosis – was 11.9%.
Of note, the impressive 91.1% primary patency rate at 12 months fell off sharply to 80.7% at 390 days, prompting comment from session cochair Dr. Elazer Edelman.
“I am struck by what happened to these patients at the end of 1 year. Not to detract in any way from the value and importance of what you’ve shown, but the fact that at 1 year we get this precipitous decline is something we as a group ought to be investigating,” said Dr. Edelman, a cardiologist who is professor of health sciences and technology at the Massachusetts Institute of Technology, professor of medicine at Harvard University, and director of the Harvard-MIT Biomedical Engineering Center.
“We have to be a little bit patient,” Dr. Scheinert replied. “We’re going to see some long-term follow-up data beginning this fall. The positive message here is that at 6 months we see almost no events, which is an achievement because typically we already see the first step down in the results curve by then. And we see patency results at 12 months that we haven’t seen with any other therapy so far.”
Dr. Edelman retorted that while it’s clear this innovative therapy has delayed the period of vulnerability to patency loss, “Your work cannot continue to be impactful if we don’t focus on where the loss of patency occurs.”
“When we talk about adjunctive therapy, we need to think now about something innovative. We need to start thinking about how to give drugs from 6 to 12 to 18 months,” he asserted.
Dr. Scheinert is on the scientific advisory board for Medtronic, which funded the study, as well as on advisory boards for more than a dozen other medical companies.