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Background: Lactic acidosis (LA) frequently occurs after heart transplantation (HTx). It is hypothesized to be related to inotropic support or metabolic derangements from chronic heart failure. As such, restoring hemodynamic stability with mechanical circulatory support before HTx should mitigate this problem. Our aim was to evaluate the incidence and outcomes of LA after HTx., Methods: We evaluated HTx recipients January 2000 to May 2011. Post-HTx outcomes included graft dysfunction, length of intensive care unit stay, length of hospital stay, inotropic support, and survival., Results: Of 143 eligible patients, 98.6% had LA, 67% severe, after HTx. Data were analyzed based on the severity of LA. Time to peak lactate, intensive care unit stay, length of hospital stay, peak glucose, inotropic dose, graft dysfunction, and survival after HTx were similar between groups. Statistically significant differences included pretransplant support (25.6% mechanical circulatory support in nonsevere vs. 44.9% severe LA), hospitalization at the time of HTx (37.2% vs. 21.4%), glucose at the time of peak lactate (182.88 ± 69.80 vs. 221.31 ± 56.91), ischemic time (187.4 ± 63.1 vs. 215.5 ± 68.1), and duration of inotrope., Conclusion: Severe LA is common after HTx, though it appears to be transient and benign. Mechanical circulatory support after HTx does not prevent LA. High lactate levels are associated with longer ischemic times, longer duration of inotrope, and correspond with higher glucose levels. The underlying mechanism is yet to be satisfactorily elucidated.

Background: Survival of patients on left ventricular assist devices (LVADs) has improved. We examined the differences in risk of adverse outcomes between LVAD-supported and medically managed candidates on the heart transplant waiting list., Methods and Results: We analyzed mortality and morbidity in 33,073 heart transplant candidates registered on the United Network for Organ Sharing (UNOS) waiting list between 1999 and 2011. Five groups were selected: patients without LVADs in urgency status 1A, 1B, and 2; patients with pulsatile-flow LVADs; and patients with continuous-flow LVADs. Outcomes in patients requiring biventricular assist devices, total artificial heart, and temporary VADs were also analyzed. Two eras were defined on the basis of the approval date of the first continuous-flow LVAD for bridge to transplantation in the United States (2008). Mortality was lower in the current compared with the first era (2.1%/mo versus 2.9%/mo; P<0.0001). In the first era, mortality of pulsatile-flow LVAD patients was higher than in status 2 (hazard ratio [HR], 2.15; P<0.0001) and similar to that in status 1B patients (HR, 1.04; P=0.61). In the current era, patients with continuous-flow LVADs had mortality similar to that of status 2 (HR, 0.80; P=0.12) and lower mortality compared with status 1A and 1B patients (HR, 0.24 and 0.47; P<0.0001 for both comparisons). However, status upgrade for LVAD-related complications occurred frequently (28%) and increased the mortality risk (HR, 1.75; P=0.001). Mortality was highest in patients with biventricular assist devices (HR, 5.00; P<0.0001) and temporary VADs (HR, 7.72; P<0.0001)., Conclusions: Mortality and morbidity on the heart transplant waiting list have decreased. Candidates supported with contemporary continuous-flow LVADs have favorable waiting list outcomes; however, they worsen significantly once a serious LVAD-related complication occurs. Transplant candidates requiring temporary and biventricular support have the highest risk of adverse outcomes. These results may help to guide optimal allocation of donor hearts.

Background: Antibody-mediated rejection (AMR) of cardiac allografts is associated with reduced long-term graft survival, but not every patient with AMR develops premature graft failure. The tissue level mechanisms leading to graft failure in some patients with antibody-mediated rejection are poorly characterized., Methods: We assessed changes in myocardial microvessel density (number of capillaries per unit area) in endomyocardial biopsies over time using whole-slide microscopic imaging of CD34-stained slides and computer-assisted image analysis. Changes were compared among eight heart transplant recipients with multiple episodes of pathologic AMR who died from cardiovascular causes, eight age- and gender-matched patients with pathologic AMR who were still alive at a similar follow-up interval, and six matched controls without AMR or cellular rejection., Results: Microvessel density decreased in the last biopsies (mean 6.52 years post-transplant) from patients with pathologic AMR and cardiovascular mortality compared to their biopsies at 6 and 12 months post-transplant [respectively, -22% (P=.02) and -25% (P=.02)]. A similar decrease was not seen for the other groups., Conclusions: Significantly reduced myocardial microvessel density does occur in a subset of patients with pathologic AMR who have a worse outcome. These data provide insights into the interplay between AMR, microvascular injury, and clinical outcomes., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Cardiac donors routinely require vasoactive agents for circulatory stability after brain death. Nevertheless, inotropes have been associated with direct cardiac toxicity. Our study evaluated whether the use of high-dose inotropic support in potential donors was associated with increased early myocardial necrosis (MN) and worse clinical outcomes after cardiac transplantation., Methods: The UTAH Cardiac Transplant Program (UCTP) and Intermountain Donor Services databases were queried for records between 1996 and 2009. The high-dose donor inotropic support (HDIS) group was defined as patients on dopamine >10 μg/kg/min. The incidence of early MN, intensive care unit (ICU) length of stay, length of ventilator support, and mortality was evaluated., Results: Two hundred and forty-four recipients undergoing transplant met study criteria. The average donor age was 27 yr. The incidence of MN in the HDIS (n=29) and non-HDIS (n=204) groups was 14.8% and 6.7%, respectively, OR 2.67. Total ischemic time, ventilator support time, ICU stay, and actuarial survival were similar between both groups., Conclusion: The use of high-dose inotropic support to maintain donor stability appears to have a higher trend for early post-transplant MN without an impact on clinical outcomes. With the current growing shortage of organ donors, it appears reasonable to use donors on high-dose inotropic support., (© 2011 John Wiley & Sons A/S.)

Background: Nearly 25% of patients with peripartum cardiomyopathy (PPCM) will require cardiac transplantation. Whether post-transplant outcomes differ among patients with PPCM compared with other recipients remains unsettled., Methods: The United Network for Organ Sharing database was queried for cardiac transplants, comparing characteristics and outcomes for PPCM, other women, and all others., Results: Between 1987 and 2010, 42,406 patients (9,419 women and 32,987 men) received a heart transplant. Of these, 485 women who had PPCM as the indication were younger (p < 0.001), had higher sensitization (p < 0.001), required higher intensity of cardiovascular support pre-transplant (p = 0.026), and had higher listing status (p < 0.001). Those with PPCM had more post-transplant rejection during the index transplant hospitalization (p < 0.001) and during the first year (p = 0.003). Comparing PPCM with other women and all others, graft survival was inferior (p = 0.004 and p < 0.003, respectively) and age-adjusted survival was lower (p < 0.001 and p = 0.02, respectively)., Conclusions: This large report shows outcomes of graft failure and death are inferior for recipients with PPCM, which may be partly explained by younger age, higher allosensitization, higher pre-transplant acuity, and increased rejection. More research is needed to determine management strategies to improve outcomes in PPCM heart transplant recipients., (Copyright © 2012 International Society for Heart and Lung Transplantation. All rights reserved.)

Chronic kidney disease continues to be a major limiting factor for long-term survival of heart transplant recipients. Little is known about the early use of renin-angiotensin system (RAS) blocking agents and their impact on renal function and hemodynamics in heart transplant recipients. In this cohort study all eligible recipients of orthotopic heart transplants at the UTAH cardiac transplantation program from 2001 through 2007 were divided into 2 groups-patients who were started on angiotensin-converting enzyme inhibitors or angiotensin receptor blockers within the first 4 weeks of transplantation and continued on these for ≥4 weeks during the first 3 months (RAS blockade group, n = 75) and those who were not (non-RAS blockade group, n = 52). All patients were followed for 1 year after transplantation. There were no significant differences at baseline between the 2 groups. Estimated glomerular filtration rate at 12 months was significantly higher in the RAS blockade group compared to the non-RAS blockade group (mean ± SD, 56.3 ± 22.4 vs 47.3 ± 18.1 ml/min/1.73 m(2), p = 0.036). At 12 months pulmonary artery systolic pressure was significantly lower in the RAS blockade group compared to the non-RAS blockade group (30.2 ± 7.4 vs 32.9 ± 9.3 mm Hg, p = 0.023). Left ventricular ejection fraction and pulmonary capillary wedge pressure were similar between the 2 groups. In conclusion, early RAS blockade after heart transplantation is safe, well tolerated, and associated with better renal function and hemodynamic profile at 1 year after transplantation., (Published by Elsevier Inc.)

Left ventricular assist device (LVAD) implantation before heart transplantation has been associated with formation of antibodies directed against human leukocyte antigens (HLA), often referred to as sensitization. This study investigated whether prior sensitization or LVAD type affected the degree of post-implantation sensitization. The records of consecutive HeartMate (HM) I and HM II LVAD patients were reviewed. Panel reactive antibody (PRA) was assessed before LVAD implantation and biweekly thereafter. Sensitization was defined as PRA > 10%, and high-degree sensitization was defined as PRA > 90%. An HM LVAD was implanted in 64 patients, and 11 received a HM II LVAD as a bridge to transplant. Ten HM I patients (16%) were sensitized before LVAD implantation (HM I-S), and 54 (84%) were not (HM I-Non-S). Nine HM I-S patients (90%) became highly sensitized (PRA > 90%) compared with 9 HM I-Non-S patients (16.7%; p < 0.001). The PRA remained elevated (> 90%) in 8 of the 9 (88.9%) highly sensitized HM I-S patients vs 5 of the 9 (55.6%) HM I-Non-S highly sensitized patients. The PRA levels in the rest of the HM I-S highly sensitized patients declined from 93% +/- 4% to 55% +/- 15% (p = 0.01). Among the 11 HM II patients, 1 (9%) was sensitized before LVAD implantation (PRA, 40%) and the PRA moderately increased to 80%. No other HM II patient became sensitized after implantation. Thus, 1 of 11 (9%) HM II patients became sensitized compared with 29 of 64 (45%) HM I patients (p = 0.04). Pre-sensitized patients are at higher risk for becoming and remaining highly HLA-allosensitized after LVAD implantation. The HeartMate II LVAD appears to cause less sensitization than HeartMate I.