LAUSR

Introduction Seasonal influenza vaccine is recommended in heart transplant patients. While it is typically well tolerated, there have been reports of low level histologic rejections . The influenza vaccine itself has been linked to inflammatory myopathies and has also been implicated in a case of myocarditis in a previously healthy individual . We present the first suspected case of myocarditis after influenza vaccine in a heart transplant patient. Case Report A 30-year-old African-American male with familial cardiomyopathy status post heart transplantation 18 months ago developed recurrent significant left ventricular dysfunction. Immediately post transplantation, he had acute graft dysfunction without evidence of acute cellular or antibody mediated rejection and negative donor specific antibodies. He received steroids, IVIG and plasmapheresis with restoration of graft function. 16 moths post-transplant, he had acute cellular rejection in the setting of subtherapeutic tacrolimus levels and was treated with pulse dose steroids with resolution. At 18 months, his EF dropped from 55-60% to 30-35% with a low cardiac index of 1.8, felt to be secondary to a non HLA antibodies given a negative endomyocardial biopsy. Pulse dose steroids resulted in recovery of his LV function by cardiac MRI (LVEF 52%). As part of his care he received the seasonal influenza vaccine. 3 weeks later he presented with dyspnea and fatigue. An echocardiogram at that time showed an ejection fraction of 35-40%. EMB was negative for rejection. A repeat cardiac MRI showed acute myocarditis. Although the EMB was negative for myocarditis, the sensitivity would have increased if a sample from the left ventricle was obtained. Summary This is the first case of a heart transplant patient with suspected acute myocarditis after receiving the influenza vaccine. Although alternative diagnoses cannot be excluded, the proximity of the vaccine and imaging evidence supports a direct correlation.