The relationship between coronary stent strut thickness and the incidences of clinical outcomes after drug-eluting stent implantation: A systematic review and meta-regression analysis

Background Drug-eluting stents (DESs) have been developed with thinner stent struts, and more biocompatible polymers and anti-proliferative drugs to improve the clinical performance. However, it remains unclear whether thinner struts are associated with favorable short- and long-term clinical outcomes such as target lesion revascularization (TLR), periprocedural myocardial infarction (PMI), and stent thrombosis (ST). Methods We searched MEDLINE, Embase and other online sources for randomized controlled trials (RCTs) comparing clinical outcomes between a DES and other stent(s), with independent clinical event adjudication. We investigated stent-related events (TLR, PMI, and ST) in 5 years. Each outcome was analyzed with random-effects meta-regression model against strut thickness, then adjusted for DES generation and patient and lesion characteristics. Results We identified 49 RCTs enrolling 97,465 patients, of which strut thickness ranged from 60 to 140 mu m. Incidences of 1-year TLR, PMI, and early ST were reduced with thinner stent struts, when adjusted for stent generation (adjusted relative risk [RR] per 10 mu m increase 1.12 [95% CI 1.04-1.21], 1.15 [95% CI 1.05-1.26], and 1.15 [95% CI 1.06-1.25], respectively). Strut thickness was not independently associated with incidences of 5-year TLR, late and very late ST. In addition, early DESs contributed to a higher incidence of very late ST (adjusted RR 2.97 [95% CI 1.36-6.50]). Conclusions In this meta-regression analysis, a thinner strut thickness was associated with reduced incidences of early stent-related adverse events (1-year TLR, PMI, and early ST), but not with later events (5-year TLR, late ST, and very late ST).