[305] The Frequency of Pathologist Endomyocardial Biopsy Interpretation Strongly Influences Rates of Rejection.

Marc K Halushka. Johns Hopkins University SOM, Baltimore, MD

Background: Many factors influence the incidence of treatable rejection after cardiac transplantation including patient age, sex, and medication adherence. Two pathologist-based variables also impact on the diagnosis of rejection. That is the differing opinions on Quilty lesions and whether a certain histologic pattern indicates diffuse, mild rejection (1B) or focal moderate rejection (3A). This project investigated a second pathologist-based variable: whether the incidence of rejection was based on the frequency by which pathologists evaluate surveillance endomyocardial biopsies.
Design: A retrospective analysis of all endomyocardial biopsy specimens taken at our institution for rejection surveillance from 2000-2009 was performed. Six pathologists, five of whom had specific cardiovascular pathology training, interpreted biopsies during this time. Three pathologists were active on the service, while the three other pathologists served in a backup capacity. The frequency of call rates for treatable cardiac rejection (3A, 3B, 2R or 3R) was determined for each pathologist.
Results: In all, 4,762 biopsies were included in this study. The frequency of treatable cardiac rejection was strongly impacted upon by the number of biopsies evaluated by a given pathologist over that time course (Table). The three pathologists who infrequently read these biopsies had a rate of 2R+ diagnoses that was nearly 3x as high as the more frequent pathologists (rejection rate 10.9% vs 3.8%, biopsies read 496 vs 4,266, p<0.001). Importantly, there were no large shifts in rates of rejection over the decade or significant differences in the patient population, which included adult and pediatric cases, suggesting that no extrinsic factors impacted upon these variable rates of rejection diagnoses.

Biopsy interpretation by pathologist
PathologistBiopsies InterpretedRate of 2R+Period of activity

Conclusions: This study identifies pathologist familiarity with endomyocardial biopsy as a strong factor for the incidence of rejection diagnoses among heart transplant recipients. As with all pathology specimens, comfort with the material is based upon repetition. This data suggests that at a given institution, the interpretation of endomyocardial biopsies should be performed by a more limited number of pathologists who can establish familiarity with the material.
Category: Cardiovascular

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 46, Wednesday Afternoon


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