Preoperative factors predicting saphenous vein graft occlusion in coronary artery bypass grafting: a multivariate analysis.

Saphenous vein segments are frequently used as aortocoronary bypass grafts, particularly in patients over 65 years of age. In the majority of patients, venous grafts maintain their patency for 5-6 years; however, some become occluded within 12 months after surgery. There are some defined predictive biological factors used to assess saphenous vein graft long-term patency rates, but little is known about molecular parameters for estimating the risk of early vein occlusion. The pathogenesis of this process involves the proliferation of stem cells, as well as progenitor cells, in the graft wall. Histologically, this is reflected by CD34 and CD133 expression in endothelial and smooth muscle cells. Thus, the aim of present work was to perform a multivariate analysis of stem cell and progenitor cell markers in saphenous vein graft walls before transplantation to arterial circulation and correlate these results with early graft occlusion. A total of 718 patients, who underwent coronary artery bypass grafting using a saphenous vein graft, were enrolled in this prospective study. CD34, CD133 and von Willebrand factor expression was evaluated via immunohistochemistry. A multivariate analysis revealed that strong CD133 expression in smooth muscle cells can be considered a risk factor for early graft failure. Our findings suggest that CD133 expression in smooth muscle cells of the tunica media in saphenous vein grafts obtained from coronary artery bypass graft patients before graft transplantation to coronary circulation might predict the possibility of early graft occlusion.

Caveolin 2: a facultative marker of unfavourable prognosis in long-term patency rate of internal thoracic artery grafts used in coronary artery bypass grafting. Preliminary report.

OBJECTIVES: Intimal hyperplasia leading to graft failure in patients undergoing coronary artery bypass grafting (CABG) is related to vascular smooth muscle cells (SMCs) proliferation. SMCs respond to a variety of mediators, the most important of which is platelet-derived growth factor (PDGF). The platelet-derived growth factor-induced cellular response has been shown to be mediated by caveolins. The aim of this study was to analyze CAV1-3 expression in internal thoracic artery (ITA) grafts used in CABG and correlate their expression with graft occlusion. METHODS: Six hundred patients undergoing CABG with the use of ITA grafts between 2008 and 2014 were enrolled into this prospective study. CAV1-3 expression in the ITA grafts was analyzed prior to graft transplantation into the coronary circulation via immunohistochemistry. Estimated caveolins expression pattern was then correlated with the occurrence of ITA graft failure observed within 24-months of surgery. RESULTS: Thirty-four patients developed ITA graft failure (subgroup A) and 566 study participants presented no adverse events (subgroup B). CAV1 and CAV3 expression levels in SMCs of the tunica media of the ITA grafts did not differ between the study subgroups and were not associated with the risk of graft failure. CAV2 was expressed within SMCs of the ITA grafts in 94.1% of the patients from subgroup A and 2.5% from subgroup B, and its expression was associated with ITA graft occlusion observed within 24-months after CABG. CONCLUSIONS: CAV2 expression in SMCs of the tunica media in autologous ITA transplants might indicate the risk of graft failure.