Serial assessment of coronary artery response to paclitaxel-eluting stents using optical coherence tomography.

BACKGROUND: The paucity of longitudinal, serial high-resolution imaging studies has limited our understanding of in vivo arterial response to drug-eluting stents. We sought to investigate the human coronary response to paclitaxel-eluting stent implantation, using serial optical coherence tomography assessments. METHODS AND RESULTS: Thirty patients with at least 2 significant coronary lesions in different vessels were treated with a paclitaxel-eluting stent. The most severe stenosis (lesion A) was treated at the initial procedure, and the second target vessel (lesion B) was stented 3 months later. Optical coherence tomography was performed at baseline, 3-, and 9-month follow-up for lesions A and baseline and 6 months for lesions B. Prespecified end points were percent of uncovered and malapposed struts over time. In lesions A, uncovered struts were 3.77±4.94% and 3.02±4.35% at 3 versus 9 months (P=NS). Malapposed struts were 3.55±5.16% at post-procedure, 1.51±3.52% at 3 months, and 0.60±1.82% at 9 months (P<0.05, at 3 versus 9 months). Strut-level neointimal thickness was 0.19±0.09 mm and 0.20±0.11 mm (P=NS) over time. Newly acquired malapposition was detected in 10.4% and 3.3% of 2.5-mm segments at 3- and 9-month follow-up. In lesions B, uncovered struts were 2.91±5.47% at 6-months. Malapposed struts were 4.94±6.70% post-procedure and 1.01±3.11% at 6 months (P<0.01), with 0.19±0.09-mm neointimal thickness at follow-up. CONCLUSIONS: Optical coherence tomography imaging suggested the first 3 months to be the period with most biological activity after paclitaxel-eluting stent implantation, when the proliferative reaction mainly occurs and malapposition resolves. A less active, yet continuous, dynamic arterial response, with resolution and development of malapposition, occurs through 9 months post-treatment.

Through the drug-eluting stent labyrinth.

For interventional cardiologists restenosis has represented the main limit for the successful long-term treatment of coronary artery disease. The past 2 years witnessed the extraordinary results of drug-eluting stents (DES), putting this technique at the center stage. The safety and efficacy of sirolimus and paclitaxel-eluting stents have been proved in large prospective, multicenter, randomized trials (RAVEL, SIRIUS, TAXUS II). It is possible that the introduction of DES will lead to substantial changes in the therapeutic and/or the economic strategies of the treatment of ischemic coronary artery disease (increase in the complexity of patients treated, reduction in surgical indications, growing costs). Realizing the potential value of this technology will require the successful management of more complex coronary situations (for lesions and patients characteristics). Many extreme situations are still unexplored, although for some of them studies are currently in progress or already being planned.