Influence of plaque calcium on neointimal hyperplasia following bare metal and drug-eluting stent implantation

Objectives: To examine the influence of vessel wall calcium on neointimal hyperplasia (NIH) following bare metal stent (BMS) and drug-eluting stent (DES) implantation. Background: While procedural complications with coronary stenting in calcified lesions are well reported, little is known about subsequent NIH on plaque calcium following either BMS or DES implantation. Methods: In the Study to Compare REstenosis Rate between QueST and QuaDDS-QP2 (SCORE) trial, 6 months follow-up volumetric intravascular ultrasound data were available for 41 lesions (BMS, 19; DES, 22). NIH thicknesses on superficial, deep, and noncalcified plaque were calculated at every 0.5 mm intervals over the stented segment. Calcified and less-calcified cross-sections were defined as those containing arcs of plaque calcium >= 90 degrees and <90 degrees, respectively. Results: In BMS, mean NIH thickness on both superficial (0.24 +/- 0.23 mm) and deep calcium (0.25 +/- 0.21 mm) was significantly smaller than that of noncalcified plaque (0.31 +/- 0.22 mm) (P < 0.0005). NIH area was significantly smaller in calcified cross-sections compared to less-calcified cross-sections (2.1 +/- 1.2 mm(2) vs. 3.1 +/- 1.9 mm(2), p < 0.0001). While in contrast, in DES, mean NIH thickness was similar, irrespective of the presence or location of calcium (0.03 +/- 0.05 mm vs. 0.03 +/- 0.06 mm vs. 0.03 +/- 0.05 mm, superficial vs. deep vs. noncalcified plaque, P = NS). NIH area was also similar between calcified and less-calcified cross-sections (0.3 +/- 0.6 mm(2) VS. 0.3 +/- 0.6 mm(2), P = NS). Conclusions: These results suggest that while plaque calcium may influence NIH following BMS implantation, NIH suppression using DES does not appear to be affected by the presence or location of calcium. (C) 2006 Wiley-Liss., Inc.