242 Functional, Metabolic, and Morphological Aspects of Continuous, Normothermic Heart Preservation: Effects of Different Preparation and Perfusion Techniques J. Garbade 1 , C. Krautz 1 , H. Aupperle 2 , C. Ullmann 1 , H.B. Bittner 1 , S. Dhein 1 , J.F. Gummert 3 , F.-W. Mohr 11 Heart Center, University of Leipzig, Leipzig, Germany; 2 Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany; 3 Friedrich-Schiller University Jena, Jena, Germany Purpose: Continuous blood perfusion of donor hearts for transplan- tation received increasing interest, but the optimal preparation and perfusion techniques are not clear defined. Therefore we investigate the effectivness of different strategies using continuous, normother- mic heart perfusion. Methods and Materials: Hearts of twelve pigs were randomly assigned to two groups receiving a constant pressure perfusion in a modified Langendorff system after different preparation techniques. (Group 1) Six hearts were arrested with Bretschneider HTK cardio- plegia (4°C) and then reperfused with a circulating pressure of 80-90 mmHg using leukocyte depleted autologous blood. (Group 2) Beating hearts of six pigs were explanted while immediately being reper- fused. Perfusion protocol was equivalent to Group 1, except for a lower circulating pressure (40-50 mm Hg). At different time points (baseline, 1, 6 and 12 hours after reperfusion) myocardial biopsies were taken and contractility was assessed by measuring the maximum rate of left ventricular pressure rise (p/t (max)). In all biopsies ATP concentration was measured using a bioluminescence technique. Additionally, ultrastructural alterations were investigated by electron microscopy. Results: Hypothermic cardioplegia and a higher reperfusion pressure were associated with an earlier and sharper decline of contractile function and intracellular ATP concentration. Ultrastructural alter- ations in Group 1 appeared earlier and were more distinctive than in Group 2. Endothelial ultrastructure, in particular, was better pre- served in Group 2. Conclusions: Blood perfusion provides protection against severe ischemic damage for a limited time. The use of a lower perfusion pressure, as well as avoiding cardioplegia and hypothermia, led to a significantly better and longer preservation of the perfused hearts. 243 Impact of Virtual Crossmatch on Outcomes in Heart Transplantation W.G. Cotts 1 , A.R. Tambur 2 , L. Klein 1 , K. Grady 1 , B. Lapin 3 , H. Subacius 3 , G. Ferguson 4 , E. Schupbach 4 , D. Ramon 2 , S. Zeigler 4 , P. Kansal 1 , J.B. O’Connell 1 , M. Montpetit 1 , E.C. McGee 4 1 Northwestern University, Chicago, IL; 2 Northwestern University, Chicago, IL; 3 Northwestern University, Chicago, IL; 4 Northwestern University, Chicago, IL Purpose: Increased levels of antibodies to human leukocyte antigens (HLA) in heart transplant (HT) recipients often require prospective cross-matches. The virtual crossmatch involves quantification of recipient HLA specific antibodies and the subsequent avoidance of corresponding donor antigens. The purpose of our study was to identify differences in outcomes in HT pts who had HLA specific antibodies and underwent virtual crossmatch (V-XM) vs. those who did not have HLA specific antibodies (No-XM). Methods and Materials: 61 consecutive pts received a HT between 6/1/05 and 6/30/08 in our center. Pts with HLA specific antibodies underwent V-XM. Pre-HT demographic and clinical characteristics (heart failure etiology, LVAD, NYHA class, PRA panel, and desensiti- zation), donor characteristics, and outcomes were compared be- tween the groups using two sample t-tests. Results: V-XM (n= 19) and No-XM (n= 42) pts had similar pre-HT characteristics except for PRA (by flow cytometry)  10% (84% vs. 0%, p0.001), pre HT desensitization (11% vs. 0%, p=0.03) and LVAD (58% vs. 21%, p=0.005). No significant differences were found for wait times, acute rejection, and LV function. Outcomes are described in Table. Conclusions: Despite sensitization, pts undergoing V-XM have comparable outcomes to non-sensitized pts not undergoing V-XM. This approach precluded the need for prospective cross-matches in sensitized patients, allowing expansion to a nationwide donor pool. Outcomes with virtual cross-match Variable V-XM (n19) No-XM (n42) p-value Total wait time (days), (interquartile range) 21 (50) 11 (14) p=0.15 Wait time at Status 1 (days) (interquartile range) 16 (40) 9 (11) p=0.08 Local OPO (%) 10 (53%) 17 (40) p0.2 Ischemic time (minutes) 189 47 19739 p0.2 EF(at day 90 post HT) (%) 597 585 p0.2  2R rejection within 6 months 4 (27%) [n=15] 9 (25%) [n=36] p0.2 1-year survival (%) 100% 100% OPO: Organ Procurement Organization 244 The Outcome of Treatment of 100% PRAs in Heart Failure Patients Awaiting Heart Transplantation K. Kiyosaki 1 , J. Kobashigawa 1 , E. Reed 2 , J. Moriguchi 1 , M. Kawano 1 , A. Ankrom 1 , J. Patel 1 , M. Kittleson 1 , E. Shao 1 , A. Ardehali 31 David Geffen School of Medicine at UCLA, Los Angeles, CA; 2 David Geffen School of Medicine at UCLA, Los Angeles, CA; 3 David Geffen School of Medicine at UCLA, Los Angeles, CA Purpose: Heart transplant recipients with elevated panel-reactive antibodies (PRAs), termed highly sensitized (HS), are at risk for early rejection and worse outcomes after transplantation. The success of strategies to treat patients with elevated PRAs is not clear. The purpose of the current study was to examine the outcomes of HS heart failure patients awaiting transplant. Methods and Materials: Between 1994 and 2008 we reviewed 842 patients and identified 18 HS heart failure patients awaiting transplant with pre-transplant 100% PRAs. HS was due to multipar- ity (n=11), multiple blood transfusions (n=11), homografts for congenital heart disease (n=3), previous transplant (n=1), or mechanical circulatory support (n=6). All patients received a combination of plasmapheresis (1.5 volume exchange x5 days), intravenous gamma globulin (2 gm/km over 2 days), rituximab (375 mg/m 2 weekly x4). Results: 12 of 18 patients had a mean decline in PRAs to 77.3%, and underwent transplant. Of the remaining 6 patients, 5 died within a mean 4 months of listing (range: 4 -13 months). For the 12 HS transplanted patients vs. controls of the same era, 5-year survival and freedom from CAV were comparable. However, 1-year freedom from rejection was lower in the HS patients vs. controls (58.3% vs. 90.4%, p0.001, Table). All patients received triple drug immunosuppres- sion. The HS patients also received ATG, plasmapheresis, and/or IVIG in the early postoperative period. Conclusions: Successful desensitization of heart failure patients with 100% PRAs is possible with comparable post-transplant survival, despite an increase in first-year rejection. Further study into effective protocols is necessary for those patients who fail densensitization, in whom mortality is high. The Journal of Heart and Lung Transplantation Abstracts S151 Volume 28, Number 2S