Studies on balloon angioplasty, atherectomy, and bare metal stent have shown a direct relation between residual plaque burden and restenosis. We investigated the relation between residual plaque burden and neointimal proliferation after drug-eluting stent (DES) implantation.Methods
Over a period of 12 months, 65 patients (Cypher, n = 25; Taxus, n = 28; Endeavor, n = 12) from two centers underwent intravascular ultrasound (IVUS) examination at 8.2 (interquartile range 6.8–9.5) months after coronary stent implantation in native de novo coronary arteries. IVUS images were acquired with motorized pullback at 0.5 mm/s, and cross-sectional measurements were performed within the stents at 1-mm intervals. The following measurements were obtained: (1) lumen area (LA), (2) stent area (SA), (3) external elastic membrane area (EEMA), (4) percent neointimal hyperplasia area (SA-LA/SA) × 100, and (5) percent residual plaque area (EEMA-SA)/EEMA × 100.Results
The analysis of 1,173 cross sections (Cypher, n = 436; Taxus, n = 532, Endeavor, n = 205) using mixed model to account for intrasubject correlation showed an absence of relation between percent residual plaque area and percent neointimal hyperplasia area (P = 0.189). Mean residual plaque burden outside the stent for Cypher, Taxus, and Endeavor groups was similar (45.7%, 44.8%, and 42.4%, respectively). Mean percent neointimal hyperplasia area for the Cypher, Taxus, and Endeavor groups was 12.0%, 15.0%, and 16.2%, respectively (P = 0.163).Conclusion
In patients after first-generation DES implantation and without significant in-stent restenosis, late in-stent neointimal proliferation is not related to the amount of residual plaque burden after stent implantation. This suggests against routine plaque removal before DES implantation to reduce neointimal proliferation.