Graft coronary artery disease in murine cardiac allografts: Proposal to meet the need for standardized assessment

Background: Inconsistency exists in assessing the severity of graft coronary artery disease (GCAD) in studies that use mouse models. The central issue associated with this inconsistency is the lack of a standardized approach for assessing mouse GCAD. Methods: We propose a new histologic definition of GCAD based on 3 successive stages (endotheliitis, premature lesion, and mature lesion) that mark the progression of this condition. In addition to these qualitative measures of GCAD, we propose including 2 additional morphometric parameters (percentage of luminal narrowing and intima-to-media ratio) and a measure of distribution (percentage of affected vessels) in the routine quantification of GCAD. Results: We introduce 2 new mouse models of GCAD as examples that satisfy these criteria. Conclusion: The proposed assessment criteria may simplify data collection and interpretation of results in various models of GCAD.