Drug-eluting stents show delayed healing: paclitaxel more pronounced than sirolimus

• Published in: European heart journal 2007-04, Vol.28 (8), p.974-979
• Main Authors: van Beusekom, Heleen M.M., Saia, Francesco, Zindler, Jaap D., Lemos, Pedro A., Hoor, Stijn L. Swager-ten, van Leeuwen, Maarten A.H., de Feijter, Pim J., Serruys, Patrick W., van der Giessen, Willem J.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Biological and medical sciences; Cardiology. Vascular system; Coronary Restenosis - physiopathology; Coronary Restenosis - prevention & control; Drug Implants; Female; Humans; Immunosuppressive Agents - administration & dosage; Male; Medical sciences; Middle Aged; Paclitaxel - administration & dosage; Pharmacology. Drug treatments; Sirolimus - administration & dosage; Stents; Tubulin Modulators - administration & dosage; Wound Healing - drug effects
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehm064

Aims To understand wound healing after drug-eluting stents (DES) placement in humans, we studied the histology of in-stent restenosis (ISR) tissue obtained by atherectomy from bare metal stents (BMS) and DES in comparison with de novo atherosclerosis. Methods and results The tissue was retrieved from ISR in ten sirolimus-eluting stents (SES) and nine paclitaxel-eluting stents (PES), six BMS, and nine stenotic de novo atherosclerotic lesions and processed for histology and immunocytochemistry. Patients with ISR in PES showed a significantly higher incidence of unstable angina upon presentation for re-intervention (P = 0.046). De novo tissue tended to be more collagen rich, whereas ISR tissue tended to be more proteoglycan rich. In all groups, cell content consisted almost exclusively of smooth muscle cells. Histology showed that fibrinoid in ISR tissue was present only in DES (P = 0.004), as late as 2 years following DES placement, indicating a persistent incomplete healing response. The amount of fibrinoid, given as a percentage of total tissue in each atherectomy specimen, was greater in PES than in SES (17 vs. 5%, P = 0.026). Conclusion ISR in DES shows incomplete neointimal healing as late as 2 years after implantation. Patients with ISR in PES presented with more unstable angina and showed more pronounced signs of delayed healing than SES.