531 Monoclonal Gammopathy of Undetermined Significance (MGUS) Does Not Predict Cardiac Amyloid Type

Abstract

negative rejection and to assess for a possible new rejection category. Methods and Materials: We evaluated 892 pts transplanted from 1994 to 2009 and identified 19 with cardiac dysfunction and negative biopsy for cellular rejection and AMR. A 2:1 control group of heart transplant pts without AMR and matched for age, sex, time from transplant, served as controls. The following outcomes were assessed: subsequent 3-year survival, freedom from cardiac allograft vasculopathy (CAV, stenosis 30%), and freedom from non-fatal major adverse cardiac events (NFMACE: myocardial infarction, heart failure, percutaneous coronary intervention, defibrillator, stroke, or new peripheral vascular disease). Results: Biopsy-negative rejection occurred on average 43 38 months post transplant. Treatment included high dose corticosteroids, anti-thymocyte globulin, and/or intravenous immune globulin. Mean LVEF was 26 8% and improved to 48 8% in all patients alive (13/19 pts) at 1 year (4 pts died and 2 were retransplanted). Subsequent 3-year survival was significantly lower in the biopsy-negative group compared to controls (47% vs. 92%, p 0.001). The biopsy-negative group also demonstrated significantly lower subsequent freedom from CAV (63% vs. 87%, p 0.032) and lower freedom from NF-MACE (74% vs. 97%, p 0.005). Conclusions: Biopsy negative rejection with cardiac dysfunction has poor outcome and represents a possible new category for rejection. Isolation of biomarkers and search for underlying mechanism may further characterize this form of rejection. A new category of biopsy negative rejection should be considered for the ISHLT biopsy grading scale.