FROM TCT 2016
An everolimus-eluting resorbable scaffold appeared to be safe and effective for percutaneous coronary intervention (PCI) in patients with diabetes and noncomplex coronary lesions, according to a study presented at the Transcatheter Cardiovascular Therapeutics annual meeting and published simultaneously in the Journal of the American College of Cardiology: Cardiovascular Interventions.
Patients with diabetes constitute an important and increasingly prevalent subgroup of PCI patients, who are at high risk of adverse clinical and angiographic outcomes such as MI, stent thrombosis, restenosis, and death. This is thought to be due to diabetic patients’ greater level of vascular inflammation and tendency toward a prothrombotic state and more complex angiographic features, said Dean J. Kereiakes, MD, of the Christ Hospital Heart and Vascular Center, Lindner Research Center, Cincinnati.
Dr. Kereiakes and his associates performed the prespecified formal substudy, designed in conjunction with the U.S. Food and Drug Administration, to support a diabetic indication for the resorbable scaffold. It was funded by Abbott Vascular, maker of the device. The study involved 754 patients who participated in three clinical trials and one device registry assessing 1-year outcomes. Even though this represents the largest study to date of patients with diabetes, it “remained underpowered to precisely evaluate low-frequency events such as scaffold thrombosis,” the coauthors noted (JACC Cardiovasc Interv. 2016 Oct 31. doi: 10.1016/j.jcin.2016.10.019).
The substudy participants all received at least one resorbable scaffold in at least one target lesion. A total of 27.3% were insulin dependent and nearly 60% had HbA1c levels exceeding 7.0%. Notably, 18% of all the treated lesions in this analysis were less than 2.25 mm in diameter as assessed by quantitative coronary angiography, and approximately 60% had moderately to severely complex morphology.
The primary endpoint – the rate of target-lesion failure at 1-year follow-up – was 8.3%, which was well below the prespecified performance goal of 12.7%. This rate ranged from 4.4% to 10.9% across the different trials. A sensitivity analysis confirmed that the 1-year rate of target-lesion failure was significantly lower than the prespecified performance goal.
The rates of target-lesion failure, target-vessel MI, ischemia-driven target-lesion revascularization, and scaffold thrombosis were significantly higher in diabetic patients who required insulin than in those who did not. Older patient age, insulin dependency, and small target-vessel diameter all were independent predictors of target-lesion failure at 1 year.
The overall 1-year rate of scaffold thrombosis in this study was 2.3%, which is not surprising given the study population’s risk factors. For diabetic patients with appropriately sized vessels of greater than 2.25 mm diameter, the scaffold thrombosis rate was lower (1.3%).
In addition to being underpowered to assess rare adverse events, this study was limited in that it reported outcomes at 1 year, before resorption of the device was complete. It also reflects the first-time clinical experience with a resorbable scaffold for most of the participating investigators, “and one would expect that as with all new medical procedures, results will improve over time with increased operator experience,” the coauthors wrote.
Dr. Kereiakes reported being a consultant to Abbott Vascular, and his associates also reported ties to the company and to other industry sources.