OBJECTIVE: To analyze angiographic factors related to remodeling of the right internal thoracic artery (RITA) using a new quantitative technique of the target coronary grafting area. METHOD: In the period from January 1992 to 2002, 452 consecutive patients were submitted to coronary artery bypass grafting (CABG) with RITA "in situ" through the transverse sinus. In this sample, 32 patients were submitted to at least one postoperative coronariography study after receiving RITA grafts. The studies were analyzed by the CASS II® software. The angiographic criteria assessed were the proximal and distal diameters of the RITA, coronary area irrigated by the target vessel, TIMI flow score, quantitative coronary angiography(QCA), dominant flow grade and the existence of patent lateral branches of the RITA. RESULTS: The mean follow-up period was 42 months, ranging from 6 to 204 months. The mean proximal diameter of the RITA was of 2.639 mm ± 0.09 and the distal diameter was 2.159 mm ± 0.1 (p < 0.001). The coronary irrigated by the target marginal branch presented a ß coefficient of 0.424 (p=0.001) and diameter of the stenosis (QCA) of the marginal branch gave a ß coefficient of 0.55 (p=0.001) adjusted by weight, height, time surgery/study, TIMI flow score, angina functional class and systemic hypertension. Multiple regression modeling demonstrated an adjusted R2 of 0.696 (p<0.0001). CONCLUSION: This study, using angiographic evaluation, demonstrated that the coronary area and proximal diameter (QCA) of the marginal branch stenosis were independent factors in RITA remodeling in the postoperative of CABG.
Internal mammary-coronary artery anastomosis; Heart catheterization; Image processing, computer-assisted
