Impact of vessel size, lesion length and diabetes mellitus on angiographic restenosis outcomes: Insights from the NIRTOP study

Background: The primary objective of the current analysis was to define the impact of vessel size, lesion length, and diabetes on clinical and angiographic restenosis following implantation of the NIRFLEX stent. Methods and results: Clinical and angiographic restenosis outcomes and multivariate predictors were compared between patients treated in 'small' (<3 mm, n=113 pts/133 lesions) versus 'large' (≥3 mm, n=41 pts/53 lesions) vessels; between 'tubular' (10-20 mm lesion length n=49 pts/51 lesions) versus 'discrete' (<10 mm lesion length n=103 pts/133 lesions) lesions; and between 'diabetic' (n=30/35 lesions) versus 'non-diabetic' (n=128/156 lesions) patients using the flexible closed-cell design 'bare-metal' NIRFLEX stent in patients with native coronary artery disease. At six month follow-up, target vessel revascularization (TVR) and target lesion revascularization (TLR) rates were significantly less frequent in the 'large' versus 'small' vessel group (2.4% versus 16.8% for TVR, P=0.016, 0% versus 12.4% for TLR, P=0.022). Likewise, angiographic late loss was lower in 'large' versus 'small' vessels (0.54 versus 0.70 mm, P=0.05). Lesion length affected MACE rates but not angiographic restenosis. Angiographic late loss was greater in diabetics compared to the non-diabetic group (0.89 versus 0.60 mm, P=0.003). Using a multivariate model, diabetes mellitus (odds ratio=2.65, P=0.047) and post-procedure in-stent MLD (mm) (odds ratio=0.178, P=0.0019) were major determinants of restenosis. Conclusion: Clinical and angiographic restenosis outcomes following NIRFLEX stent implantation were dependent upon vessel size, lesions length, post-procedural stent lumen dimensions, and the diabetic status.