Residual Graft Pathology During CABG as a Minimally Invasive Diagnostic Pathway for Transthyretin Amyloidosis

BACKGROUND: Concomitant coronary artery disease is not uncommon in cardiac amyloidosis (CA), yet diagnostic pathways remain challenging when myocardial ischemia and CA coexist. CASE SUMMARY: We describe a 72-year-old man presenting with heart failure and severe 3-vessel disease in whom transthyretin amyloidosis was ultimately diagnosed using residual arterial graft tissue obtained during urgent coronary artery bypass grafting (CABG). Histologic examination of the residual left and right internal thoracic arteries and radial artery revealed transthyretin amyloidosis amyloid deposition, enabling rapid, minimally invasive confirmation of systemic amyloidosis at a time when bone scintigraphy risked false-positive interpretation due to myocardial ischemia and endomyocardial biopsy posed a procedural risk. The patient demonstrated marked clinical improvement after CABG and was started on vutrisiran. DISCUSSION: This case highlights arterial graft pathology as a practical and rarely used diagnostic opportunity for suspected CA in patients undergoing CABG, suggesting a potential role for graft-based screening in selected individuals. TAKE-HOME MESSAGES: Residual arterial graft tissue obtained during CABG may provide a practical, minimally invasive means of confirming systemic amyloidosis when nonbiopsy pathways may be inconclusive or endomyocardial biopsy poses procedural risk.