The presence of transthyretin cardiac amyloidosis in patients undergoing coronary artery bypass graft surgery.

BACKGROUND AND AIMS: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly recognised albeit rare and frequently delayed diagnosis in patients with a variety of underlying cardiac presentations. This cross-sectional observation study aimed to determine the prevalence of cardiac amyloidosis in an undifferentiated adult population with coronary artery disease undergoing coronary artery bypass graft surgery (CABG) using direct histological analysis of cardiac tissue.

METHODS

Consecutive eligible patients, with no known history of ATTR-CM or monoclonal gammopathy, aged 60 years and over, undergoing CABG were enrolled in the study. Myocardial samples were taken perioperatively from bypass cannulation area and sent for histopathological analysis to look for infiltration of the myocardium with transthyretin (TTR) amyloid.

RESULTS

Among 101 patients enrolled, 95 were male, and 6 were female. The mean age of the patients was 70.4 years (95% CI; 69.3 - 71.5). Seventy-nine tissue samples were obtained from 70 participants and sent for histological analysis. NYHA Class 2 symptoms were present in 44.3%. The incidence of hypertension was 88.6%, and dyslipidaemia was 87.1%. Regarding medications, 75.7% were taking ACE-i/ARB/ARNI, 68.6% beta-blockers, and 91.4% were taking a statin. No complications arose as a result of myocardial sampling at surgery. No cardiac amyloidosis was identified on immunohistochemistry and Congo red analysis.

CONCLUSION

In this large series of older patients undergoing CABG, infiltration of myocardial tissue with ATTR was not seen and the yield of routine myocardial biopsy to detect ATTR is low.