covid

This prospective single-center study investigates whether COVID-19 leaves persistent molecular and structural alterations in vascular grafts and lung tissue of patients undergoing elective isolated coronary artery bypass grafting (CABG). A total of 31 patients were enrolled, including 15 with documented SARS-CoV-2 infection 6–12 weeks prior to surgery and 16 without a history of COVID-19. Excess saphenous vein and internal mammary artery segments, and when available, lung tissue samples, were analyzed using light microscopy, immunohistochemistry (α-SMA, BCL-2, iNOS, TNF, TGF-β1, VEGF), and transmission/scanning electron microscopy. Histopathological evaluation revealed endothelial injury, fibrosis, cytoskeletal disruption, and increased inflammatory marker expression in previously infected patients, despite similar perioperative clinical outcomes. The study demonstrates that clinically recovered COVID-19 patients may still carry long-lasting pulmonary and vascular tissue alterations with potential implications for graft patency and long-term cardiovascular prognosis.