A single center investigation of bare-metal or drug-eluting stent restenosis from 1633 consecutive Chinese Han ethnic patients

BACKGROUND: Stents are widely used in China but the clinical impression is somehow that restenosis is less common because of the lower prevalence of coronary artery disease (CAD) and associated risk factors in Chinese populations. However, no large-sample published studies are available on angiographic stent restenosis including those of bare-metal stent (BMS) or drug-eluting stent (DES) in Chinese Han ethnic population. METHODS: A total of 1633 consecutive patients with CAD who had undergone coronary stenting, quantitative coronary angiography (QCA) were retrospectively studied. At the time of stent implantation and at 7 months post-stenting 675 patients had a follow-up angiography. Statistical analysis was made with the chi-square test for categorical variables, unpaired t test for continuous variables, univariate or multivariate regression for baseline and angiographic characteristics and the Kaplan-Meier method for rate of target lesion revascularization (TLR). RESULTS: Stent restenosis was defined as > or = 50% diameter stenosis in the dilated segment. A total of 675 patients with 1074 lesions were subjected to angiographic follow-up for 7 months on average. Of these lesions, 448 were implanted with BMS whereas 626 lesions with DES. At 7 months, bare-metal in-stent restenosis occurred in 148 lesions (33.0%), and bare metal in-segment restenosis in 155 lesions (34.6%) in contrast to drug-eluting in-stent restenosis in 48 lesions (7.7%) and drug-eluting in-segment restenosis in 73 lesions (11.7%) (P < 0.001 compared with BMS respectively). Late loss in both in-stent and in segment was higher in BMS than in DES groups (1.00 +/- 0.69) vs (0.28 +/- 0.52); (0.78 +/- 0.71) vs (0.21 +/- 0.52), P < 0.001 respectively. Angulated lesion, lesion length, pre-procedural minimal luminal diameter (MLD), and BMS were independent predictors for TLR, (P < 0.01 respectively), whereas current smoker, ostial lesion, and stent overlapping, post-procedure in-stent MLD, lesion length, and stent types were independent predictors for in-segment restenosis (P < 0.01 respectively). Standard coronary risk factors such as hypertension, hyperlipidemia, diabetes, and history of CAD were not associated with a higher rate of restenosis caused by BMS or DES implantation in our Chinese Han ethnic population. CONCLUSIONS: Coronary stenting including BMS or DES implantation in Chinese Han ethnic patients is associated with a restenosis rate comparable to that demonstrated in previous studies from the western countries, and predictors of stent restenosis are somehow different from those in the western population.