In a blinded, multicenter, investigator-initiated, noninferiority, randomized, clinical trial (AIDA ), Absorb had greater device-related ST (3.5%) with mean follow-up of 707 days compared with metallic DES (0.9% p < 0.001) (5). Likewise, 2-year data from the pivotal Absorb III clinical trial showed higher rate of ST and target lesion failure in Absorb (4). The device-related VLST for BVS was 0.8% vs. Although initial trial results seemed promising, higher rates of unfavorable outcomes, such as device-related thrombosis in Absorb, especially occurring beyond 1 year, were reported compared with everolimus-eluting metallic stents in a meta-analysis of randomized, controlled trials (3). It was thought that, as long as short-term and mid-term outcomes were at least equivalent to current-generation DES, the advantages of Absorb would begin to appear after 32 months, when the polymer is substantially degraded in vivo. ![]() On average, BVS struts occupied 27% of the vessel wall compared with only 13% for most metallic DES. ![]() Yet, because its polymeric structure is not as strong as metal, Absorb had to have thicker struts (150 μm) to improve its radial strength, which still is on the order of one-half that of DES. The Absorb stent (Abbott Vascular, Santa Clara, California) represents the most advanced attempt to create this type of device. ![]() Nonetheless, disadvantages to this type of system remain, including impaired coronary vasomotion, development of early neoatherosclerosis, and long-term retention of polymer-coated metal.īioresorbable vascular scaffold (BVS) was developed with the goal of overcoming these shortcomings. Newer-generation DES are made with thinner struts and have a significantly lower rate of stent thrombosis (ST) than first-generation DES (2). In the era of thick strut (i.e., ∼140 μm) first-generation drug-eluting stents (DES), delayed healing (i.e., uncovered struts) of the stented segment was the primary cause of late stent thrombosis, which in some series occurred at an annual rate of 1.3% through at least 10 years of follow-up (1). ![]() Very late stent thrombosis (VLST) is an unpredictable and potentially life-threatening complication of percutaneous coronary intervention.
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