myocardial pH higher than conventional hypothermic storage. Use of intermittent perfusion, as opposed to a single antegrade dose may lead to improved preservation of the donor heart. This may have a favorable effect on the number of potential donors by allowing for longer distance procurement. 305 INCREASED INCIDENCE OF REJECTION EARLY AFTER HEART TRANSPLANTATION DUE TO DONOR-RECIPIENT ETHNIC MISMATCH Y. Potashnik, 1 E.L. Shabtai, 2 Y. Har Zahav, 1 J. Lavee, 31 Heart Institute, Sheba Medical Center, Tel Hashomer, Israel; 2 Statistics Services, Tel Aviv - Sourasky Medical Center, Tel Aviv, Israel; 3 Heart Transplantation Unit, Sheba Medical Center, Tel Hashomer, Israel Purpose: The impact of donor-recipient (D/R) ethnic matching on results of heart transplantation has been poorly studied. As many recipients followed in our heart transplant clinic have received hearts from ethnic mismatched donors either in Israel or in multitude of countries abroad, we have examined the linkage between D/R ethnic identity and the rejection rate following transplantation. Methods and Materials: We studied all 111 patients who underwent heart transplantation between 1990 and 2006 and are currently followed up in our clinic. Clinical, demographic and endomyocardial biopsies data was retrieved from patients’ records. Recipients’ ethnic origin was Jewish in 97, Arab in 7, non-Jewish Caucasian in 6 and Hispanic in 1 patient. Donors’ ethnic origin was non-Jewish Caucasian in 47, Jewish in 46, Asian in 8, Arab in 7 and Hispanic in 3 patients. Cardiac rejection was defined as mild (ISHLT grades 1, 2) and moderate/severe (ISHLT grades 3A, 3B, 4). Results: A D/R ethnic mismatch was found in 60 patients and ethnic matching in 51 patients. Results of cardiac biopsies performed within the first 3 months after transplantation were significantly associated with ethnic matching: No rejection was found in 57.7% of 275 biopsies in the ethnic matched group compared to 40.4% of the 241 biopsies in the ethnic mismatched group. Mild rejection was identi- fied in 31.9% of the biopsies in the matched group compared to 48.7% in the ethnic mismatched group (p=0.0002). There was no difference in the rate of moderate/severe rejection between the two groups (10.4% vs 10.9%). No statistically significant linkage could be estab- lished between ethnic matching and rejection in biopsies performed beyond 3 months after transplantation. Rejection rate was indepen- dent of place of transplantation and D/R gender match. Conclusions: D/R ethnic matching in heart transplantation leads to a significant decrease in early rejection rate. Based on studies linking early graft rejection to the development of chronic graft vasculopa- thy, this matching might impact long term survival. 306 EX VIVO INFRARED SCANNING FOR THE DETECTION OF TRANSMITTED CORONARY DISEASE IN HUMAN DONOR HEARTS R.S. Poston, 1 N. Burris, 1 C. Tang, 1 B.P. Griffith, 11 Division of Cardiac Surgery, University of Maryland, Baltimore, MD Purpose: Older donors increase the risk of transmitting coronary artery disease (CAD) by transplant but the impact of mild CAD on graft outcomes is unknown. We examined the feasibility of using a novel imaging technology, optical coherence tomography (OCT), to accurately quantify donor CAD ex vivo. Methods and Materials: Three human donor hearts (refused clini- cally due to serology results) were evaluated: 39 yr old diabetic, 55 yr old smoker (10 pack-years) and 16 yr old male (no CAD risk factors). After cardiectomy, ex vivo OCT images of the coronary arteries were obtained by cannulating the left main artery. Maximum % luminal narrowing and total plaque burden were determined off-line using proprietary software. Systolic recovery was determined after reperfu- sion with whole blood at 37°C using a Langendorff preparation. Results: Despite normal coronary angiography, OCT images revealed areas of concentric intimal thickening, particularly in the left main coronary (Fig. A) and eccentric plaques in the proximal LAD (Fig. B) in each heart. Maximum luminal narrowing calculated by OCT was 32.7, 28.5 and 12.9 % (Fig. D), with strong correlations noted to histology (R=0.89). The distal coronary showed normal intima (Fig C). The total plaque volume was calculated at 63.3, 29.2, and 12mm3. Each heart showed full recovery (i.e. developed pressure 100 mmHg) after reperfusion. Conclusions: Although acceptable for transplant based on clinical criteria (other than for positive serologies), these consecutive donor hearts all had CAD when imaged by this high resolution technique. Given that results can be obtained in “real time” without affecting myocardial recovery, this novel application of OCT may help eluci- date the true prevalence of transmitted CAD. 307 ERYTHROPOEITIN MAY IMPROVE LONG TERM PRESERVATION OF THE DONOR HEART S. Zangwill, 1 K. Mussatto, 1 J. Su, 1 J.E. Baker, 11 Pediatrics - Children’s Research Institute, Medical College of Wisconsin, Milwaukee, WI Purpose: Erythropoietin (Epo) is well known to stimulate red cell production and has recently been shown to protect the heart against injury from ischemia/reperfusion. The University of Wisconsin (UW) solution is an effective preservative for cold storage of the cardiac allograft. The efficacy of Epo in the setting of cardiac preservation for transplantation is unknown. We evaluated the effect of Epo on preservation of the donor heart in an animal transplant model using UW solution. Methods and Materials: 8 week old male rats were used for this study. The hearts were excised and flushed with UW solution and stored at 4°C for 18 hours. Rats (n=8) were treated with Epo (500 U/kg i.v.) 15 minutes prior to harvest and flush with UW solution. Control rats (n=8) were treated with saline. Myocardial contractile The Journal of Heart and Lung Transplantation Abstracts S169 Volume 26, Number 2S