Background: Smooth muscle cells, present in the saphenous vein (SV) tunica media, may contribute to late occlusion of venous aortocoronary grafts. The aim of present study was to evaluate expression of selected cytoskeletal proteins in tunica media of SV grafts obtained from patients undergoing coronary artery bypass grafting (CABG) and correlate procured results to late venous graft failure observed in these patients.
Methods: The study involved 218 patients (mean age of 62.5 ± 8.7 years) who underwent primary isolated CABG with the use of at least one venous aortocoronary bypass graft. Expressions of alpha-smooth muscle actin, smooth muscle-myosin heavy chain, calponin and cytokeratin 8 in SV wall were estimated by means of immunohistochemistry. The primary clinical endpoint was defined as the presence of any coronary artery disease (CAD) progression symptom while angiographic one as significant stenosis in the venous graft.
Results: Thirty-eight (18.1%) patients have reached the primary clinical endpoint. Freedom from clinical CAD deterioration was 0.95 ± 0.02, 0.87 ± 0.03 and 0.83 ± 0.04, for 12-, 24-,36-month follow-up, respectively. Forty-four study participants have reached the angiographic endpoint. Multivariate logistic regression analysis revealed an increased expression of cytokeratin 8 accompanied by calponin under expression in SV tunica media were independent risk factors for venous graft failure.
Conclusions: An increased expression of cytokeratin 8 and weak of calponin in tunica media of SV grafts might be useful markers of unfavorable long-term prognosis in CABG patients. In the future, assessment of their expression may enable to select the most appropriate candidates for SV grafts.