Assessment of Second- and Third-Generation Drug-Eluting Stents on Chronic Coronary Angioscopy　― Multicenter Study on Intra-Coronary AngioScopy After Stent (MICASA) Prospective Data Analysis

Background:The vascular response, in terms of quality and quantity, of the second- and third-generation drug-eluting stents (2G- and 3G-DES, respectively) was assessed prospectively on coronary angioscopy (CAS).Methods and Results:The Multicenter study on Intra-Coronary AngioScopy After Stent (MICASA) is a multicenter CAS registry. A total of 107 DES (71 2G- and 36 3G-DES) were prospectively observed on CAS 8.7±2.7 months after percutaneous coronary intervention. Neointimal coverage (NC) grade was evaluated using a 4-point grading scale, from 0 (no coverage) to 3 (complete coverage). Plaque yellow color (YC) was also assessed using a 4-point grading system, from 0 (white) to 3 (bright yellow). Max-NC (2G-DES vs. 3G-DES: 2.14±0.68 vs. 2.44±0.73, P=0.023); min-NC (1.07±0.48 vs. 1.39±0.60, P=0.002), and dominant-NC (1.57±0.69 vs. 2.08±0.84, P=0.002) were significantly higher and the YC grade (1.23±0.82 vs. 0.86±0.76, P=0.031) significantly lower in the 3G-DES group than in the 2G-DES group. There was no significant difference in the presence of thrombus (28.2% vs. 22.2%, P=0.51) between the 2G- and 3G-DES groups.Conclusions:The higher NC grade and lower YC grade in 3G-DES than in 2G-DES might be associated with better long-term clinical outcome, which remains to be determined in future studies.