Angiotensin-Converting Enzyme Inhibition Early After Heart Transplantation.

BACKGROUND: Cardiac allograft vasculopathy (CAV) remains a leading cause of mortality after heart transplantation (HT). Angiotensin-converting enzyme inhibitors (ACEIs) may retard the development of CAV but have not been well studied after HT. OBJECTIVES: This study tested the safety and efficacy of the ACEI ramipril on the development of CAV early after HT. METHODS: In this prospective, multicenter, randomized, double-blind, placebo-controlled trial, 96 HT recipients were randomized to undergo ramipril or placebo therapy. They underwent coronary angiography, endothelial function testing; measurements of fractional flow reserve (FFR) and coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR); and intravascular ultrasonography (IVUS) of the left anterior descending coronary artery, within 8 weeks of HT. At 1 year, the invasive assessment was repeated. Circulating endothelial progenitor cells (EPCs) were quantified at baseline and 1 year. RESULTS: Plaque volumes at 1 year were similar between the ramipril and placebo groups (162.1 ± 70.5 mm3 vs. 177.3 ± 94.3 mm3, respectively; p = 0.73). Patients receiving ramipril had improvement in microvascular function as shown by a significant decrease in IMR (21.4 ± 14.7 to 14.4 ± 6.3; p = 0.001) and increase in CFR (3.8 ± 1.7 to 4.8 ± 1.5; p = 0.017), from baseline to 1 year. This did not occur with IMR (17.4 ± 8.4 to 21.5 ± 20.0; p = 0.72) or CFR (4.1 ± 1.8 to 4.1 ± 2.2; p = 0.60) in the placebo-treated patients. EPCs decreased significantly at 1 year in the placebo group but not in the ramipril group. CONCLUSIONS: Ramipril does not slow development of epicardial plaque volume but does stabilize levels of endothelial progenitor cells and improve microvascular function, which have been associated with improved long-term survival after HT. (Angiotensin Converting Enzyme [ACE] Inhibition and Cardiac Allograft Vasculopathy; NCT01078363).

Proceedings of the AST heart allocation meeting at the American Transplant Congress, Philadelphia, Pennsylvania, May 4, 2015.

Ensuring fair and equitable allocation of donor hearts in the US is the charge of the Organ Procurement and Transplantation Network (OPTN). However, the recent increase of candidates waiting without a corresponding increase in available donors, higher waitlist mortality rates in higher status patients, the presence of disadvantaged subgroups, and the changing management of heart failure patients with increased VAD usage, has necessitated review of allocation policy. Therefore, the Heart Subcommittee of the OPTN/UNOS Thoracic Committee is exploring a further-tiered allocation system, devising a "straw man" model as a starting point for modeling analyses and public discussion. On May 4, 2015, an American Society of Transplantation (AST)-endorsed forum to discuss these potential proposed changes took place. Attendees included 41 people, mostly highly experienced transplant cardiologists and cardiothoracic surgeons, representing 19 heart transplant centers across the US, UNOS, and the Scientific Registry of Transplant Recipients (SRTR). There was unanimous agreement that the potential proposed policy will require careful wording to avoid ambiguity and "gaming" of the system, and strong support for abolishment of local organ sharing in favor of geographic sharing. However, contention existed concerning the appropriate prioritization levels of ECMO, temporary VAD/TAH patients as well as the 30-day LVAD listing.

Randomized pilot trial of gene expression profiling versus heart biopsy in the first year after heart transplant: early invasive monitoring attenuation through gene expression trial.

BACKGROUND: The endomyocardial biopsy (EMB) is considered the gold standard in rejection surveillance post cardiac transplant, but is invasive, with risk of complications. A previous trial suggested that the gene expression profiling (GEP) blood test was noninferior to EMB between 6 and 60 months post transplant. As most rejections occur in the first 6 months, we conducted a single-center randomized trial of GEP versus EMB starting at 55 days post transplant (when GEP is valid). METHODS AND RESULTS: Sixty heart transplant patients meeting inclusion criteria were randomized beginning at 55 days post transplant to either GEP or EMB arms. A positive GEP ≥30 between 2 and 6 months, or ≥34 after 6 months, prompted a follow-up biopsy. The primary end point included a composite of death/retransplant, rejection with hemodynamic compromise or graft dysfunction at 18 months post transplant. A coprimary end point included change in first-year maximal intimal thickness by intravascular ultrasound, a recognized surrogate for long-term outcome. Corticosteroid weaning was assessed in both the groups. The composite end point was similar between the GEP and EMB groups (10% versus 17%; log-rank P=0.44). The coprimary end point of first-year intravascular ultrasound change demonstrated no difference in mean maximal intimal thickness (0.35±0.36 versus 0.36±0.26 mm; P=0.944). Steroid weaning was successful in both the groups (91% versus 95%). CONCLUSIONS: In this pilot study, GEP starting at 55 days post transplant seems comparable with EMB for rejection surveillance in selected heart transplant patients and does not result in increased adverse outcomes. GEP also seems useful to guide corticosteroid weaning. Larger randomized trials are required to confirm these findings. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT014182482377.