Neointimal coverage of sirolimus-eluting stents 6 months and 12 months after implantation: evaluation by optical coherence tomography.

BACKGROUND: Optical coherence tomography (OCT) is a new imaging modality with resolution of approximately 10 microm and can be employed to visualize intracoronary characteristics. Sirolimus-eluting stents (SES) are susceptible to late thrombosis due to delayed re-endothelialization over the stent struts, which may result in acute myocardial infarction or death. This study was designed to evaluate the re-endothelialization and neointimal coverage of SES with OCT 6 months and 12 months after implantation. METHODS: A total of 36 patients enrolled in the study underwent OCT examination 6 months (17 patients) and 12 months (19 patients) after SES implantation. The strut apposition to the vessel wall and neointimal coverage on SES struts were evaluated by OCT. RESULTS: Forty-six SES and 6561 struts were analyzed. At 6 months, 3041 struts (98.7%) were well-apposed and 39 struts (1.3%) were malapposed. At 12 months, 3434 struts (98.6%) were well-apposed and 47 struts (1.4%) were malapposed. Furthermore, only 4 SES at 6 months (18.2%) and 10 SES at 12 months (41.7%) were fully covered by neointimal growth. The average neointimal thicknesses covering the analyzed struts at 6 months and 12 months were (42+/-28) microm and (88+/-32) microm, respectively. There were 1989 struts at 6 months (72.1%) and 1461 struts at 12 months (45.6%) with neointimal thickness <100 microm. CONCLUSIONS: OCT was able to visualize the strut apposition to the vessel wall and neointimal coverage on SES struts. At 6-month and 12-month follow-up examinations most struts were covered with thin neointima, but few of the entire SES showed full coverage. To prevent late-stent thrombosis in the presence of uncovered stent struts, longer dual antiplatelet drugs therapy should be recommended.

Early and late clinical outcomes following coronary perforation in patients undergoing percutaneous coronary intervention.

Coronary perforation is a rare but serious complication that occurs during percutaneous coronary intervention (PCI). This study examines the frequency of coronary perforation during PCI, evaluates the management strategies used to treat perforations, and describes the long-term prognosis of patients who have developed coronary perforation during PCI. Coronary perforations were found in 69 (0.93%) of 7,443 consecutive PCI procedures, occurring more often after use of a new device (0.86%) than after use of balloon angioplasty (0.41%) (p<0.05). Coronary perforation was attributable solely to the coronary guidewire in 27 (0.36%) cases. Coronary perforations were divided into 2 types: (1) Those with epicardial staining without ajet of contrast extravasation (type I, n=51), and (2) those with a jet of contrast extravasation (type II, n= 18). Patients with type I and type II perforations were managed by observation only (35% and 0%, respectively), reversal of anticoagulation (57% and 94%), pericardiocentesis and drainage (27% and 61%), and prolonged perfusion balloon angioplasty (16% and 100%). Two patients with type II perforations required emergency coronary artery bypass surgery. There were no in-hospital deaths. Late pseudoaneurysms developed in 18 (28.6%) patients during the 13.4 +/- 11.3 months' follow-up period, and were more common in patients with type II perforations (72.2% vs 11.1% with type I perforations; p<0.001). During the follow-up period, no patient had evidence of coronary rupture. The results suggest that coronary perforation is uncommon after PCI, and can be managed without cardiac surgery in the majority of cases. Late pseudoaneurysms developed in some patients, particularly in patients with type II perforations, but there were no late consequences of coronary perforation after PCI.