Different vascular healing patterns with various drug-eluting stents in primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: optical coherence tomographic findings

The introduction of optical coherence tomography has provided a new method for evaluating the vascular response to drug-eluting stents (DESs). We used optical coherence tomography to compare neointimal coverage and stent malapposition among DESs in patients with ST-segment elevation myocardial infarction. Optical coherence tomography was performed at 9 months after implantation of 3 types of DESs at the culprit lesions in 46 patients with ST-segment elevation myocardial infarction (16 sirolimus-eluting stents [SESs, Cypher Select], 11 paclitaxel-eluting stents [PESs, Taxus Liberte], and 19 zotarolimus-eluting stents [ZESs, Endeavor Sprint]). The neointimal thickness and apposition at each strut at each 1-mm interval and the presence of thrombi in each stent were evaluated. A total of 11,512 stent struts were analyzed. SESs had the thinnest neointimal thickness (SES 62 +/- 43 mum vs PES 244 +/- 142 mum vs ZES 271 +/- 128 mum, p <0.001). The incidence of uncovered struts and malapposed struts were significantly greater in SESs and PESs than in ZESs (SES vs PES vs ZES, 16.2 +/- 17.8% vs 4.7 +/- 7.4% vs 0.6 +/- 1.5%, respectively, p = 0.001; and 4.0 +/- 8.2% vs 2.1 +/- 4.5% vs 0 +/- 0%, respectively, p = 0.001). Thrombus was also detected more often in SESs and PESs than in ZESs (SES, 6 [38%] vs PES, 3 [27%] vs ZES, 1 [5%], p = 0.02). In conclusion, the rate of stent strut coverage and malapposition were significantly different among the DES types in ST-segment elevation myocardial infarction. In particular, most stent struts in ZESs were covered with neointima and well-apposed. These findings imply that the type of DES might affect the vascular response in thrombotic lesions of ST-segment elevation myocardial infarction.