254 Highly Sensitive Transplant Rejection Surveillance Using Targeted Detection of Donor Specific Cell Free DNA

Abstracts J.A. Vázquez de Prada,1 J. Delgado,2 M. Gomez-Bueno,3 M.J. Paniagua,4 F. Perez-Villa,5 S. Mirabet,6 J.M. Arizon,7 J.L. Lambert,8 L. Almenar,9 F. Gonzalez-Vilchez.1 1Cardiology Service, University Hospital Marqués de Valdecilla, Santander, Cantabria, Spain; 2Cardiology Service, University Hospital 12 de Octubre, Madrid, Spain; 3Cardiology Service, University Hospital Puerta de Hierro, Majadahonda, Madrid, Spain; 4Cardiology Service, University Hospital A Coruña, A Coruña, Galicia, Spain; 5Cardiology Service, Hospital Clinic, Barcelona, Cataluña, Spain; 6Cardiology Service, University Hospital Santa Creu i Sant Pau, Barcelona, Cataluña, Spain; 7 Cardiology Service, University Hospital Reina Sofia, Cordoba, Andalucia, Spain; 8Cardiology Service, University Hospital Central de Asturias, Oviedo, Asturias, Spain; 9Cardiology Service, University Hospital La Fe, Valencia, Spain. Purpose: We sought to determine the incidence, risk factors and clinical consequences of acute rejection after calcineurin-inhibitor (CNI) replacement with a proliferation signal inhibitor (PSI) in maintenance heart transplant recipients. Methods and Materials: Relevant clinical data were retrospectively obtained for long-term heart transplant recipients from 9 spanish centers in whom CNI-therapy was completely replaced with a PSI between October 2001 and March 2009. Allograft rejection was diagnosed whenever an endomyocardial biopsy, echocardiographic or clinical findings prompted anti-rejection therapy or an augmentation of baseline immunosuppression. Results: In 284 patients, CNI therapy was totally replaced with sirolimus (127 pts.) or everolimus (157 pts) at a mean of 8 years from transplantation. The actuarial rate of rejection was 8.3 % at 1 year, 11.9 % at 2 years, 12.6 % at 3 years and 14.6 % at 4 years. The incidence rate of rejection after conversion was 4.9 per 100 patient-years. In the preconversion period (between the second year after transplantation and the time of conversion) the rejection incidence rate was 2.2 per 100 patient-years (p ⫽ 0.013 with respect to postconversion period). In the multivariate analysis, rejection risk was associated with a history of late rejection prior to PSI conversion (p ⫽ 0.001), early conversion (⬍ 5 years) after transplantation (p ⫽ 0.006) and age ⬍ 50 years at the time of conversion (p ⫽ 0.02). Concomitant therapy with mycophenolate mofetil was a protective factor (p ⫽ 0.004). The occurrence of post-conversion rejection did not result in either a decline in left ventricular ejection fraction or an excess in mortality during the follow-up. Conclusions: In long-term heart transplant recipients, CNI replacement with a PSI portends an excess in acute rejection, apparently without prognostic implications. Some clinical characteristics can help to anticipate the risk of rejection. 252 Sirolimus Based Immunosuppression Attenuates Cardiac Allograft Vasculopathy Progression by Decreasing Fibrotic Component of Coronary Atherosclerotic Plaque E. Raichlin, Y. Matsuo, N.L. Pereira, B.S. Edwards, R.P. Frantz, A.L. Clavell, R.J. Rodeheffer, B.A. Boilson, J.A. Schirger, A. Lerman, S.S. Kushwaha William J.von Liebig Transplant Center, Mayo Clinic, Rochester, MN; Center for Coronary Physiology and Imaging, Mayo Clinic, Rochester, MN; Division of Cardiology, Universisty of Nebraska Medicak Center, Omaha, NE. Purpose: Replacement of CNI with SRL based immunosuppression attenuates the progression of cardiac allograft vasculopathy (CAV). We evaluated the effect of SRL on tissue characterization of the coronary atherosclerotic plaque using 3D-virtual histology intravascular ultrasound (3D VH-IVUS). Methods and Materials: Forty two cardiac transplant recipients were converted to SRL 3.5⫾3.8 years after transplantation with complete calcineurin inhibitor (CNI) withdrawal. Ninety four control subjects 4.5⫾3.9 years from transplantation were maintained on CNIs. 3D VH-IVUS were performed at baseline and 0.9⫾0.6 years later. Each plaque segment was classified following 4 types of tissue characteristics: fibrous, fibrofatty, dense calcium, and necrotic core. On the basis of VH-IVUS plaque characteristics, coronary plaque was defined as inflammatory (VH-IP: necrotic core and dense calcium ⬎30%) and noninflammatory (VH-NIP: necrotic core and dense calcium ⱕ30%). Results: The increases in the plaque volume (⌬PV/L; -0.3⫾1.6 mm3/mm vs. 0.7⫾2.0 mm3/mm, p⫽0.034) and plaque index (⌬PI; -0.5⫾7.7% vs. 4.1⫾7.8%, p⫽0.019) were attenuated in the SRL group compared to the CNI group due to significant reduction in the fibrotic tissue component during 1 year follow-up

S91 (-0.5⫾0.8 mm3/mm vs. 0.7⫾1.3 mm3/mm, p⫽0.03). This SRL effect was significant in the subgroup of patients with the VH-IP at baseline.

Conclusions: Substituting CNI with SRL based immunosuppression attenuates CAV progression by decreasing the fibrotic tissue component. Patients with inflammatory plaque may particularly benefit from conversion to the SRL based immunosuppression. 253 Long-Term Renal Function in the TICTAC Trial: Outcomes beyond 5 Years D.A. Baran, C. Guerrero-Miranda, J. Pieretti, N. Hochbaum, M.E. Goldschmidt, S. Pardi, M. Camacho, M.J. Zucker. Transplant Center, Newark Beth Israel Medical Center, Newark, NJ. Purpose: The Tacrolimus in Combination, Tacrolimus Alone Compared (TICTAC) trial examined the use of tacrolimus (TAC) monotherapy (MONO) as compared to TAC / mycophenolate mofetil (MMF) in de novo heart transplant patients (pts). Whether renal function might be worse long-term without MMF is unclear. We report the renal outcomes of pts through 72 months post-transplant. Methods and Materials: From 4/04-9/08, 150 pts were enrolled in this prospective, randomized trial, as previously reported. Half of the pts were randomized to the MONO group and were maintained on TAC alone after steroid discontinuation. The other half were in the combination therapy (COMBO) group and were treated with TAC/MMF. Serial measurements of serum creatinine (SCr) and TAC trough levels are reported. Results: The table shows the SCr and TAC levels during the first 7 years post-transplant. The number of pts with data available at each time point is listed as well. The data shows similar renal function following the initial post-transplant year. This data supports the renal safety of either a TAC monotherapy or TAC/MMF regimen post-transplant coupled with steroid weaning. Table 1

TAC Level and SCr Over Time Post-Transplant

Timepoint Posttransplant (months)

MONO Serum Cr (Median ⫾ SD)

COMBO SCr (Median ⫾ SD)

p-Value

MONO TAC Trough

COMBO TAC Trough

p-Value

# Pts with Data

12

1.64⫾0.7

1.44⫾0.49

0.05

9.8⫾3.1

9.8⫾3.8

0.95

150

18

1.44⫾0.45

1.36⫾0.45

0.57

9.0⫾3.1

8.4⫾3.1

0.7

111

24

1.53⫾0.49

1.35⫾0.42

0.22

8.4⫾2.6

8.6⫾2.7

0.7

108

30

1.52⫾1.13

1.40⫾0.48

0.2

9.0⫾3.4

9.0⫾3.0

0.9

109

36

1.41⫾0.82

1.34⫾0.55

0.27

8.4⫾2.3

9.3⫾4.7

0.2

115

48

1.48⫾1.2

1.32⫾0.2

0.22

7.6⫾2.1

7.5⫾2.0

0.6

86

60

1.32⫾1.3

1.39⫾0.7

0.6

8.7⫾2.1

8.4⫾3.0

0.2

62

72

1.27⫾0.43

1.41⫾0.43

0.43

6.9⫾1.9

7.8⫾1.9

0.2

39

Conclusions: Despite initial renal impairment which was noted in both study groups at one year, long-term renal function was preserved over 72 months. Targeting lower TAC levels could also optimize outcomes in the future. 254 Highly Sensitive Transplant Rejection Surveillance Using Targeted Detection of Donor Specific Cell Free DNA M. Hidestrand,1 S. Zangwill,2,4 A. Tomita-Mitchell,1,4 A. Oliphant,3 P. Hidestrand,2,4 C. Castleberry,2 G. Stendahl,4 M. Otto,4 H. Liang,1 M. Goetsch,1 T. Ellis,5 B. Shames,1 P. Simpson,1 S. Berger,2,4 J. Tweddell,1,2,4 M.E. Mitchell.1,4 1Surgery, Medical College of

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The Journal of Heart and Lung Transplantation, Vol 31, No 4S, April 2012

Wisconsin, Milwaukee, WI; 2Pediatrics, Medical College of Wisconsin, Milwaukee, WI; 3Aria Diagnostics, San Jose, CA; 4Herma Heart Center, Children’s Hospital of Wisconsin, Milwaukee, WI; 5Blood Center of Wisconsin, Milwaukee, WI. Purpose: Circulating donor specific cell free-DNA (cf-DNA) can be isolated from recipient plasma and may be a stable biomarker for cellular injury. We designed a blinded prospective pilot study to test the accuracy of a targeted method of detection and quantification of donor specific cf-DNA in heart transplant recipients. Methods and Materials: 25 individual plasma samples were collected from 16 pediatric heart transplant recipients in two clinical settings: at surveillance biopsy (12 patients, 14 samples) and during admission for rejection (4 patients, 11 samples). Samples were blinded and processed. Cf-DNA was extracted. Total cf-DNA was quantified and percent donor specific DNA was measured using targeted next generation sequencing (DANSR, Aria Dx). Results: All samples collected at the initial diagnosis of rejection showed elevated percentage of donor cf-DNA, P ⬍ 0.002. 11 of 13 samples collected during routine surveillance biopsy contained below 1% donor cf-DNA. Of the two samples with elevated donor cf-DNA, one was from a patient who was subsequently admitted in rejection and one from a patient with known positive cross match. The ratio of donor cf-DNA consistently declined with antirejection therapy, P ⬍ 0.038.

College of Medicine, Philadelphia, PA; 3Wyeth Pharmaceuticals (now Pfizer), Collegeville, PA; 4Hospital Universitario A Coruna, La Coruna, Spain. Purpose: A recent study demonstrated better renal function at 1 year with sirolimus (SRL) conversion vs continued CNI in cardiac transplant patients with renal insufficiency. A post hoc analysis was conducted to identify predictors of biopsy-confirmed acute rejection (BCAR) and change in GFR with SRL conversion. Methods and Materials: Predictors analyzed were prespecified based on previous literature. The 13 and 6 predictors for BCAR and GFR improvement, respectively, were investigated by univariate and multivariate analysis with a stepwise algorithm (type 1 error: 0.30 for model entry; 0.10 for elimination). A predictor was considered statistically significant if the P value was ⱕ0.1. Results: GFR and BCAR analyses were conducted in the ITT population (n⫽115) and SRL group (n⫽57), respectively. On univariate analysis, MMF ⱕ1000mg significantly predicted BCAR (P⫽.001). On multivariate, MMF ⱕ1000mg remained predictive (P⫽.007) and non-white race was independently associated with BCAR (P⫽.064). On univariate, change from baseline in GFR between SRL and CNI was significantly different in patients with preexisting diabetes vs without (P⫽.077). On multivariate analysis, significant improvement in GFR was seen in patients without preexisting diabetes in the SRL vs CNI group (P⬍.001). Preexisting diabetes was the only predictor with treatment interaction (P⫽.022). Lower baseline GFR was significantly associated with greater GFR improvement, independent of treatment (P⫽.057).

Conclusions: Low MMF (ⱕ1000mg) and non-white race were identified as predictors of BCAR associated with SRL use. GFR improvement with SRL was seen in patients without preexisting diabetes. Sponsor:Pfizer Inc, Collegeville, PA. 256 Use of Thymoglobulin after Heart Transplantation: Is There a Role in African American Patients? B. Coleman, J. Patel, L. Czer, J. Mirocha, J. Kobashigawa. CedarsSinai Heart Institute, Los Angeles, CA.

Conclusions: Percentages of donor cf-DNA increase during rejection and fall following treatment. These changes can be monitored. A larger study is needed. 255 Predictors of Acute Rejection or Renal Function Improvement in Cardiac Transplant Patients with Renal Insufficiency A. Zuckermann,1 H. Eisen,2 S. See Tai,3 H. Li,3 C. Hahn,3 M.G. Crespo-Leiro.4 1AKH Wien, Vienna, Austria; 2Drexel University

Purpose: Disparity in heart transplant (HTx) outcomes between African Americans (AA) and Caucasian American (CA) patients (pts) is known. These differences may due to genetic differences in the metabolism of immunosuppressant. The role of induction therapy in the AA population has not been established. We evaluated whether use of Thymoglobulin induction (Thy) improved outcomes in AA using the UNOS database. Methods and Materials: 11,521 consecutive adult pts (2065 AA and 9456 CA) from the UNOS database transplanted between 1/2000 and 3/2011 were included. Data were further analyzed using three age groups; Group 1 age 21-39, Group 2 age 40-59 and Group 3 age ⱖ60. 5 yr survival was estimated by Kaplan-Meier method. Survival was compared across groups by Log-Rank and Wilcoxon tests. Cox proportion hazards models were used to obtain hazard ratios and 95% confidence intervals. Results: For all ages, AA vs CA (with/without Thy) had significantly lower 5-yr actuarial survival (Log-Rank P ⬍ 0.0001) (figure). For AA alone, Thy vs none showed a trend for survival benefit (HR 0.84 with 95% CI ⫽ 0.68-1.04, P ⫽ 0.062). Comparing Thy by age in AA shows significant survival benefit for the younger Group 1 but a trend towards worsening survival in the older group 3 (Group 1 HR⫽0.67 with 95% CI ⫽