VA ECMO as a Bridge to Transplantation: Emergent Eligibility and Outcomes

Abstracts S227 5( 87) L-Arginine and Methylarginines Prior to and After Heart Transplantation J. Lundgren ,1 A. Sandqvist,2 M. Hedeland,3 U. Bondesson,3 G. Wikström,4 G. Rådegran.1  1Cardiology, Clinical Sciences, Lund University, Sweden; 2Pharmacology and Clinical Neuroscience, Clinical Pharmacology, Umeå University, Sweden; 3Chemistry, National Veterinary Institute Uppsala, Sweden; 4Medical Sciences, Cardiology, Uppsala University, Sweden. Purpose: Endothelial (ET) function and the nitric oxide (NO) pathway have been investigated in heart failure, but studies are lacking after heart transplantation (HT). We therefore investigated plasma concentration of substances in the NO-pathway prior to and after HT, in relation to hemodynamic parameters. Methods: 12 patients (52.2 yrs, 2 females), heart transplanted between June 2012 and February 2014 and evaluated at Lund Hemodynamic Lab, at rest, prior to HT and repeatedly thereafter, were included. At the post-HT evaluations, all patients had normal heart function and none had acute cellular rejection episodes needing therapy. Blood samples collected during right heart catheterization were stored in the Lund Cardio Pulmonary Register and subsequently analyzed for plasma concentrations of L-arginine, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) with liquid chromatography - tandem mass spectrometry. 12 healthy, age-matched, non-smoking controls were compared. Results: Pre-HT, L-Arginine concentration was lower (p< 0.001) and ADMA, as well as SDMA, higher (p< 0.003 and p< 0.001) in patients than controls, resulting in low L-Arginine/ADMA-ratio (Figure 1). Already four weeks after HT, L-Arginine normalized whereas ADMA and SDMA were unaltered (p= ns) at both postoperative evaluations. Consequently the L-Arginine/ADMA-ratio improved, but did not normalize. Moreover, the L-Arginine/ADMA-ratio correlated inversely to pulmonary vascular resistance (PVR) six months after HT. Conclusion: The L-Arginine concentration normalizes after HT. However, as ADMA is unchanged, the L-Arginine/ADMA-ratio remain low, correlating inversely to PVR. Together these findings suggest that after HT; i.) the L-Arginine/ADMA-ratio reflects pulmonary vascular tone; and ii.) NO-ET function is partly restored. Novel medical therapies may therefore be beneficial to optimize post-HT ET function. Considering the good post-operative outcome, the biomarker states could be considered “normal” after HT.

Purpose: VA ECMO is a salvage therapy for refractory cardiogenic shock (RCS). Its appropriate use as a bridge to orthotopic heart transplantation (OHT) remains uncertain. In a cohort of patients with RCS supported on VA ECMO, we sought to determine their eligibility for emergent OHT listing, and their outcomes with respect to recovery, transition to durable support, or transplantation. Methods: Between January and December 2015, we identified 73 patients aged 18-72 who required acute support with VA ECMO for RCS at our institution. Patients supported for primary graft failure or non-cardiac indications were excluded (Fig 1). The remaining cohort (n= 55) was analyzed for contraindications to OHT using criteria at our institution, in accordance with the ISHLT 2016 Listing Criteria. Results: Among the 55 patients included in the analysis, mean age was 59.3 +10.1 years and 40 (73%) were male. Common etiologies of RCS were postcardiotomy shock (22), acute coronary syndrome (19), and decompensated heart failure (6). Forty-three patients (78%) had one or more contraindications to emergent OHT listing (Fig 1). These reasons included poorly controlled diabetes (5), severe vascular disease (5) substance abuse (15), noncompliance (5), and obesity (8). Complications on VA ECMO precluding listing were dialysis (17), uncertain neurological status (15), and coagulopathy (19). Among the 12 (22%) without contraindications, 11 (92%) survived to discharge (8 with adequate native cardiac function, 3 on mechanical support). None underwent emergent OHT evaluation or transplantation. Of the nine patients with follow-up at our institution only 2 were readmitted with HF. Conclusion: Comorbidities and complications limit the use of VA ECMO as a bridge to emergent transplantation. In our cohort, patients without contraindications had a favourable prognosis. Further work is needed to identify the subset of patients who might benefit from emergent listing on VA ECMO while avoiding pre-emptive transplantation in those with otherwise acceptable outcomes.

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5( 88) VA ECMO as a Bridge to Transplantation: Emergent Eligibility and Outcomes M.V. Habal , A.R. Garan, V.K. Topkara, K. Takeda, F. Latif, S. Restaino, M. Yuzefpolskaya, R. Bijou, P. Colombo, H. Takayama, Y. Naka, M. Farr.  Columbia University, New York, NY.

Clinical Usefulness of Cardiac Magnetic Resonance Imaging After Heart Transplantation G. Poglajen ,1 A. Cerar,1 R. Zbacnik,2 G. Zemljič,1 S. Frljak,1 J. Ksela,3 I. Knezevic,3 P. Berden,2 B. Vrtovec.1  1Advanced Heart Failure and Transplantation Programme, Dept. of Cardiology, University Medical Center Ljubljana, Ljubljana, Slovenia; 2Institute of Radiology, University Medical Center Ljubljana, Ljubljana, Slovenia; 3Dept. of Cardiovascular Surgery, University Medical Center Ljubljana, Ljubljana, Slovenia. Purpose: Cardiac magnetic resonance imaging (cMRI) appears to have a high negative predictive value when used as a screening tool for allograft rejection