Evaluation of an Infrapopliteal Drug-Eluting Resorbable Scaffold: Design Methodology for the LIFE-BTK Randomized Controlled Trial

Critical limb-threatening ischemia (CLTI) is a severe condition characterized by rest pain and ischemic tissue loss that affects 5% to 10% of people with peripheral artery disease. In the United States, there are few Food and Drug Administration-approved devices for the primary treatment of arteries below-the-knee (BTK). Unfortunately, all suffer from high restenosis rates due to intimal hyperplasia, elastic recoil, and untreated dissection because of a lack of scaffolding. The Esprit BTK system is a resorbable, drug-eluting scaffold device with the potential to address an unmet need in people suffering from CLTI because of infrapopliteal atherosclerosis. The LIFE-BTK (pivotaL Investigation of saFety and Efficacy of drug-eluting resorbable scaffold treatment-Below The Knee) randomized controlled trial (RCT) is a prospectively designed premarket evaluation of the Esprit BTK drug-eluting resorbable scaffold used in the treatment of those patients. The LIFE-BTK trial enrolled 261 subjects with CLTI for the RCT and a further 7 subjects for a pharmacokinetic substudy. The objective of the RCT was to evaluate the safety and efficacy of the Esprit BTK scaffold compared to percutaneous transluminal angioplasty. The primary efficacy end point was a composite of limb salvage and primary patency at 12 months. The primary safety end point is freedom from major adverse limb events and peri-operative death at 6 months and 30 days, respectively. Clinical follow-up care is planned for 5 years. Novel devices must be tested in RCTs to evaluate their safety and efficacy compared to the standard of care if we are to improve outcomes for this challenging group of patients. [Display omitted] •Infrapopliteal interventions are still limited by durability because of restenosis and acute recoil.•Evidence suggests drug-eluting resorbable scaffolds may improve mid-long-term patency.•A randomized controlled trial comparing the Esprit scaffold to percutaneous angioplasty.•The trial design methodology is presented in detail.