Different patterns of neointimal coverage between acute coronary syndrome and stable angina after various types of drug-eluting stents implantation; 9-month follow-up optical coherence tomography study

Background: Acute coronary syndrome (ACS) is an independent risk factor for late stent thrombosis which might be related to the impaired vascular healing after drug-eluting stent (DES) due to the disruption of plaques and thrombus formation. Therefore, we investigated the vascular response after various DES implantations between ACS and stable angina pectoris (SAP) using optical coherence tomography (OCT). Methods: Ninety-one patients [49 ACS: 20 sirolimus-eluting (SES), 12 paclitaxel-eluting (PES) and 17 zotarolimus eluting stent (ZES) and 42 SAP: 15 SES, 12 PES and 15 ZES] underwent OCT at 9 months after stent implantation. Neointimal coverage and malapposition were evaluated in 21,939 struts in 2269-mm stented segments. Results: In the ACS group, the incidence of uncovered and malapposed struts was significantly higher (8.9 +/- 13.7 vs 2.9 +/- 6.2%, p=0.01 and 2.2 +/- 5.6 vs 0.5 +/- 2.0%, p=0.02). Among the three DESs tested, SES showed a significantly higher rate of uncovered struts in the ACS group (17.3 +/- 13.4 vs 4.4 +/- 6.2%, p=0.003). PES had a trend toward higher rate of uncovered and malapposed struts in the ACS groups (6.7 +/- 7.6 vs 4.0 +/- 9.0%, p=0.13) while ZES was similar in both groups. Conclusion: The patterns of neointimal coverage and malapposition at 9 months after DES implantation were different between ACS and SAP, and variable among the DES type between two groups. Therefore, the present study suggests that vascular response after DES implantation might be influenced by both clinical presentation and type of DES. (C) 2009 Elsevier Ireland Ltd. All rights reserved.