regimens need to be considered in CAV patients, especially those with a history of previous rejection. (681) Outcomes of Induction Immunosuppressive Therapy in Combined Heart-Liver Transplantation H. Abdulameer Cedars-Sinai Medical Center, Los Angeles, CA. Purpose: Combined heart-liver transplantation is increasingly performed in the United States. The utility and outcomes of induction immunosup- pression in this patient population is not well studied. Methods: Recipients of combined heart-liver transplants between January 1 st , 2000 and June 30 th , 2018 were identified in the United Network of Organ Sharing database. Survival and rejection episodes were reviewed among these patients with or without induction therapy and by various induction agents: ATGAM (horse-derived polyclonal antibody), Thymo- globulin (rabbit-derived polyclonal antibody), Campath (Alemtuzumab), OKT3 (Muromonab) and Interleukin-2 receptor antagonists (IL-2 RA). Results: A total of 260 patients received combined heart-liver transplanta- tion in the United States between January 1 ST , 2000 and June 30 th , 2018. The mean age was 46.4 years, mean donor age was 30.1 years, 30% of recipients were females, 64.6% were White, 19.6% were Black, 11.9% were Hispanic, 14.7% were diabetic, 7.1% were on dialysis, 61.5% were on life support and 20% were listed as status 1A at the time of transplantation. These findings were similar between the induction and the non-induction groups. Of the 260 patients, 134 (52%) patients received induction therapy. Of these, 36% received IL-2 receptor antagonists, 28% received Thymoglobulin, 23% received ATGAM, 6% received Campath and 6% received OKT3. Survival in combined heart-liver transplant recipients was comparable to that of recipi- ents of heart transplant only (P=0.63). Across 15 years of follow up, survival was similar among patients who received induction therapy versus no induc- tion therapy (P=0.62). Subgroup analysis showed no survival difference among the studied induction agents across 15 years of follow up as well (P=0.80). Approximately 6.7% of the non-induction group patients had at least 1 episode of acute rejection versus 2.4% of the induction group patients (P=0.13), which indicates a favorable trend in the induction group. Conclusion: In this retrospective analysis of the UNOS database, recipi- ents of combined heart-liver transplantation have comparable survival to recipients of heart transplantation only. Induction immunosuppressive therapy was not associated with improved survival in patients undergoing combined heart-liver transplantation however showed a favorable trend towards less acute rejection. (682) A Novel Immunosuppressive Regiment for Cardiac Transplant Patients J. Vojnika, 1 A. Vishnevsky, 1 M. Shah, 1 D. Farzad, 1 B. Zimmerman, 1 K. Ryan, 1 C. Demastus, 1 A. Boyle, 2 R. Alvarez, 1 I. Danelich, 1 and P. Pirlamarla. 1 1 Cardiology, Thomas Jefferson University Hospital, Philadelphia, PA; and the 2 Cardiology, Largo Medical Center, Tampa Bay, FL. Purpose: Heart transplantation remains curative for end-stage heart fail- ure. The choice between immunosuppressive regimens is guided by sev- eral principles: mitigating the risk of rejection early after transplantation, limiting drug toxicity of immunosuppressants, and minimizing over-sup- pression. We sought to investigate the efficacy of a novel immunosuppres- sive regimen targeting a lower therapeutic range (LTR) for Tacrolimus without antecedent induction therapy compared with a standard therapeu- tic range (STR). The protocol was implemented after 2016 and included the administration of Tacrolimus to a goal trough of 6-8 ng/mL immedi- ately post transplant, Mycophenolate mofetil 1000-15000 mg BID, and Prednisone 1 mg/kg/day post-op divided into two doses and tapered by 5 mg Daily. Methods: A retrospective chart review was performed comparing trans- plant outcomes utilizing the novel LTR immunosuppression regimen compared to STR from 2008-2019. Primary outcomes included infection, bone marrow suppression and rejection within the first 3 years of transplantation. Results: Of the 83 patients analyzed, 25 (30%) received the lower Tacroli- mus dosing regimen (LDR), and 58 received the standard dosing regimen (SDR). Patients in the LDR group were younger (56.2 +/- 12.2 years vs 61.8 +/- 10.4 years) and less likely to be male (68% vs 87.9%). Rates of high risk CMV donor/recipient status was similar between the two groups. There was no statistically significant difference between the LDR group and SDR group with respect to rates of infection (44% vs 34.5%, p=0.41), bone marrow suppression (20% vs 13.8%, p=0.47), or > 2R CMR (24% vs 32.8%, p=0.42). Conclusion: In this single-center study we compared a conventional post-transplant immunosuppression regimen with one that utilized a lower Tacrolimus trough goal (6-8ng/mL). There was no statistical dif- ference between the two groups in rates of rejection, bone marrow sup- pression, or infectious complications. We present a successful novel immunosuppression regiment that could serve to benefit patients with intolerance to higher doses of calcineurin inhibitors with no adverse outcomes. Future studies are needed to determine the impact of LTR on renal function. (683) Impact of Induction Therapy in Cardiac Transplant Patients in the Current Era E. Vaishnav, 1 D. Pham, 1 T. Hess, 1 A. Baber, 1 A. Fiedler, 2 J. Smith, 2 and R. Dhingra. 1 1 Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI; and the 2 Cardiothoracic Surgery, University of Wisconsin- Madison, Madison, WI. Purpose: Approximately half of all heart transplant programs utilize induction therapy during the early postoperative period. However, differ- ences in survival using modern induction therapies have not been investi- gated in the current era. Methods: We selected all adult patients from the United Network for Organ Sharing (UNOS) database who underwent first time heart trans- plantation between 2008-2017 and received either induction therapy with anti-thymocyte globulin (ATG; n= 3747) or basiliximab (n=5157) or had no induction treatment (n=10,485). Kaplan Meier curves and multivariable Cox models compared the differences in survival among all three groups. Results: Mean age of patients was 53.5 years and 25.7% were females. In general, patients who received ATG had longer wait times on the waitlist, had slightly higher ischemic times and there were fewer male recipients with female donors in this group. Upon follow up, 4,236 patients died. Kaplan Meier curves as displayed (Figure) suggested improved survival for those who received ATG compared to Basiliximab. In multivariable models, compared to patients who received ATG, those who received Basiliximab had higher risk of death (hazard ratio 1.11; p 0.02). There were no statistical differences in survival when patients who received ATG were compared to those who did not receive any induction therapy. Conclusion: In conclusion, induction therapy with ATG is associated with marginal survival benefit compared to induction therapy with basiliximab however there were no differences in long-term survival of patients who receive ATG when compared to those who did not receive any induction therapy. Abstracts S279