Purpose: Previous studies have shown remarkable decrease in severity of functional mitral regurgitation (FMR) after left ventricular assist device (LVAD) implantation with mechanical unloading. This study aimed to identify the change of FMR and mitral geometry in LVAD patients. Methods: We retrospectively reviewed all patients who underwent LVAD implantation and had significant FMR without mitral valve procedure between January 2010 and December 2017. All patients underwent echo- cardiographic examination preoperatively and 1 month after LVAD implantation. We defined significant FMR as MR color jet area / left atrial area &gt; 0.2. We measured mitral annular diameter (MAD) and posterior (Dp) and apical (Da) displacement of the coaptation point of mitral leaflets on echocardiogram. Patients were divided into 2 groups, patients with and without AF. Results: 106 patients were identified, 82 with no AF and 24 with AF. Mitral geometry significantly changed after LVAD insertion in both groups (table). Preoperative MAD was smaller in patients without AF (39.0 +/-4.5 vs. 41.2 +/-3.8mm; P=0.04) and reduced following LVAD in both postoperative (30.3+/-5.4 vs. 36.5 +/-4.1mm; P<0.0001), however, the changes of MAD before and after surgery were larger in patients with no AF (8.8 +/-5.0 vs. 4.7 +/-3.2 mm; P=0.0003). There were no significant differences in Da between groups. Patients with AF had a higher preva- lence of significant FMR at 1 month after LVAD implantation than patients with no AF (4% vs. 17%; P =0.03). Conclusion: LVAD implantation significantly changed mitral geometry, however, the changes were less in patients with AF resulting in greater residual FMR. (1023) WITHDRAWN (1024) The Burden of Total Artificial Heart Patients and Complications after Heart Transplantation O. Seguchi, J. Youn, D. Geft, R. Cole, A. Shen, K. Nishihara, S. Mersola, C. Runyan, J. Hajj, D. Ramzy, J.A. Kobashigawa and J. Moriguchi. Smidt Heart Institute at Cedars-Sinai, Los Angeles, CA. Purpose: Increased perioperative risk has been observed in patients with left ventricular assist devices (LVAD) and total artificial hearts (TAH) undergoing heart transplantation with worse outcomes in TAH patients. The purpose of this study was to review perioperative transplant outcomes in TAH vs LVAD patients at a high-volume transplant center. Methods: We reviewed perioperative transplant outcomes of 46 TAH patients and 85 LVAD patients from 2010-2018. Outcomes included peri- operative transfusions (units of packed red blood cells, fresh frozen plasma, platelets, cryoprecipitate), time in the operating room (OR), inten- sive care unit (ICU) days immediately post-transplant, freedom from return to OR for bleeding, freedom from primary graft dysfunction (PGD), and 1-year freedom from temporary dialysis. In addition, 1-year outcomes included survival, freedom from cardiac allograft vasculopathy (CAV), freedom from non-fatal major adverse cardiac events (NF-MACE: myo- cardial infarction, heart failure, percutaneous intervention, defibrillator/ pacemaker implant, stroke), and freedom from first-year rejection (any treated rejection (ATR), acute cellular rejection (ACR), antibody-mediated rejection (AMR)). Results: TAH patients had more perioperative blood transfusions, and had decreased freedom from return to the OR for bleeding, temporary dialysis, and NF-MACE. There were no differences between groups in the time in OR, ICU days post-transplant, and freedom from PGD, survival, CAV, and rejection. Conclusion: TAH patients appear to have increased perioperative post- transplant risk for some parameters though no difference in PGD or sur- vival compared to LVAD patients. In a high volume center, there can be acceptable post-transplant outcomes in TAH patients. Endpoints TAH (n=46) LVAD (n=85) P-value Perioperative Blood Transfusions (total units) 31.5 +/ 12.9 25.4 +/ 14.4 0.017 Time in OR (minutes) 553.8 +/ 120.3 572.7 +/ 151.3 0.466 ICU Days 11.3 +/ 11.5 8.9 +/ 10.6 0.222 Freedom from take backs to OR 82.6% 93.1% 0.049 Freedom from PGD 91.3% 83.9% 0.237 1-Year Freedom from temporary dialysis 73.9% 87.4% 0.031 1-Year Survival 89.1% 93.0% 0.430 1-Year Freedom from CAV 95.7% 94.3% 0.774 1-Year Freedom from NF-MACE 78.3% 92.0% 0.024 1-Year Freedom from ATR 84.8% 87.4% 0.653 1-Year Freedom from ACR 97.8% 95.4% 0.505 1-Year Freedom from AMR 95.7% 97.7% 0.500 (1025) WITHDRAWN (1026) Development of De Novo Aortic Insufficiency in Patients with HeartMate 3 A. Malick, 1 Y. Naka, 1 J. Sanchez, 1 C. Butler, 1 Y. Ning, 2 P. Kurlansky, 2 V. Topkara, 3 M. Yuzefpolskaya, 3 P. Colombo, 3 G. Sayer, 3 N. Uriel, 3 and K. Takeda. 1 1 Department of Surgery, Division of Cardiothoracic Surgery, Columbia University Irving Medical Center, New York, NY; 2 Department of Surgery, Center for Innovation and Outcomes Research, Columbia University Irving Medical Center, New York, NY; and the 3 Department of Medicine, Division of Cardiology, Columbia University Irving Medical Center, New York, NY. Purpose: Aortic insufficiency (AI) is common following continuous flow left ventricular assist device (CFLVAD) and is associated with morbidity and mortality. This study aims to assess the incidence of de novo AI in HeartMate 3 (HM 3) LVAD recipients and compare the outcomes with HeartMate II (HM II) patients. Methods: A retrospective review was conducted of clinical characteristics and serial echocardiograms (1 month, 6 months, and 1 year post implant) of 151 HM 3 patients implanted between Nov. 2014 and March 2019, as well as of 270 HM II patients implanted between April 2004 and Dec. 2015 at our center. Patients (n=30) were excluded from analysis for a his- tory of aortic valve (AV) surgery, concomitant AV surgery with LVAD implant, or more than trace preoperative AI left untreated. De novo AI was defined as more than mild AI. Results: In the HM 3 cohort, mean age was 58 § 12 and 84% were male. 74% received HM 3 as destination therapy. Incidence and degree of de novo AI in each group is summarized in Figure 1. 4 patients were readmit- ted due to significant AI and heart failure symptoms. Cumulative incidence curves showed that the probability of de novo AI at 1 year was 8.4% in the HM 3 cohort vs. 13% in the HM II cohort (Figure 2, p=0.29). In both cohorts, patients who had AV opening on echocardiogram at 1 month post implant were significantly less likely to develop de novo AI (100% free- dom from de novo AI at 1 year for HM 3 with open AV vs. 84% for HM 3 with closed AV, 97% for HM II with open AV vs. 76% for HM II with closed AV). Conclusion: The incidence of de novo AI is low and comparable between HM 3 and HM II patients at our center. AV opening at 1 month post implant appears to be protective of this complication. S406 The Journal of Heart and Lung Transplantation, Vol 39, No 4S, April 2020