Heart transplant recipients supported with extracorporeal membrane oxygenation: outcomes from a single-center experience.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) provides hemodynamic support in refractory cardiogenic shock and may be used after heart transplantation for primary graft dysfunction or rejection. We hypothesized that survival after ECMO support is contingent upon patient selection. METHODS: We examined consecutive adult heart transplant recipients at a single center who underwent transplantation between 1997 and 2009 and required ECMO support. Patients were divided by clinical presentation: pre-emptive therapy, escalating inotropic requirements despite support by intra-aortic balloon pump (IABP); and salvage therapy, cardiac arrest undergoing cardiopulmonary resuscitation with chest compressions. RESULTS: Between 1997 and 2009, there were 37 instances of ECMO use in 32 patients: 23 episodes (19 patients) for pre-emptive therapy and 14 episodes (14 patients) for salvage therapy; 1 patient had both pre-emptive and salvage therapy. Patients did not differ in age, gender or ischemic time. ECMO support was for a median 6 days in both groups, and the incidence of serious vascular complications was comparable (35% and 36%). In the pre-emptive therapy group, 15 episodes (79%) were associated with survival to hospital discharge and 5 patients (26%) were alive at 1 year. In the salvage therapy group, 2 episodes (14%) were associated with survival to hospital discharge and 1 patient (7%) was alive at 1 year. CONCLUSIONS: ECMO support is a viable option for adult heart transplant recipients with severe rejection and refractory cardiogenic shock. To maximize the benefit of this aggressive approach in heart transplant recipients requires early intervention, with a heightened awareness of this option to facilitate expedited use.

Donor-recipient sex mismatch portends poor 10-year outcomes in a single-center experience.

BACKGROUND: Several studies have indicated that survival after heart transplantation is affected by donor-recipient sex matching. In most studies, male recipients of a female heart have the poorest survival rates, whereas survival of female recipients is not affected by donor sex. The purpose of the current study was to determine the long-term outcomes of recipients at a large single center on uniform immunosuppression therapy in the current era. METHODS: We reviewed the records of 857 patients transplanted at a single center between 1994 and 2008. Patients were divided into 4 groups based on donor-recipient sex: male donor to male recipient (male/male, n = 506); female donor to female recipient (female/female, n = 113); male donor to female recipient (male/female, n = 106); and female donor to male recipient (female/male, n = 132). Ten-year outcomes were assessed for: survival; freedom from cardiac allograft vasculopathy (CAV); and freedom from non-fatal major adverse cardiac events (NF-MACE). RESULTS: Ten-year actuarial survival was comparable in male/male and female/female groups, at 69% and 71%, respectively (p > 0.05). Compared with the male/male group, 10-year actuarial survival was significantly lower in the sex-mismatch groups: 58% in the male/female group (p = 0.03) and 59% in the female/male group (p = 0.01). There was no significant difference in 10-year freedom from CAV or NF-MACE among the groups. CONCLUSIONS: Heart transplant patients with donor-recipient sex mismatch have lower survival, extending the results of prior studies to suggest that sex mismatch is undesirable in female, as well as male, recipients. This may impact donor selection and recipient wait time to transplantation.

The long-term outcome of treated sensitized patients who undergo heart transplantation.

BACKGROUND: Sensitized patients prior to heart transplantation are reportedly at risk for hyperacute rejection and for poor outcome after heart transplantation. It is not known whether the reduction of circulating antibodies pre-transplant alters post-transplant outcome. METHODS AND RESULTS: Between July 1993 and July 2003, we reviewed 523 heart transplant patients of which 95 had pre-transplant panel reactive antibody (PRAs) >10%; 21/95 were treated pre-transplant for circulating antibodies. These 21 patients had PRAs > 10% (majority 50-100%) and were treated with combination therapy including plasmapheresis, intravenous gamma globulin and rituximab to reduce antibody counts. The 74 untreated patients with PRAs > 10% (untreated sensitized group) and those patients with PRAs < 10% (control group) were used for comparison. Routine post-transplant immunosuppression included triple-drug therapy. After desensitization therapy, circulating antibody levels pre-transplant decreased from a mean of 70.5 to 30.2%, which resulted in a negative prospective donor-specific crossmatch and successful heart transplantation. Compared to the untreated sensitized group and the control group, the treated sensitized group had similar five-yr survival (81.1% and 75.7% vs. 71.4%, respectively, p = 0.523) and freedom from cardiac allograft vasculopathy (74.3% and 72.7% vs. 76.2%, respectively, p = 0.850). CONCLUSION: Treatment of sensitized patients pre-transplant appears to result in acceptable long-term outcome after heart transplantation.

Benefit of immune monitoring in heart transplant patients using ATP production in activated lymphocytes.

BACKGROUND: Balancing immunosuppression to prevent rejection while minimizing infection or drug toxicity risk is a major challenge in heart transplantation. Therapeutic drug monitoring alone is inadequate to measure the immune response. An immune monitoring (IM) assay (ImmuKnow; Cylex, Columbia, MD) performed on peripheral blood measures adenosine triphosphatase (ATP) release from activated lymphocytes and may predict the immune state. Therefore, we sought to determine the utility of IM in heart transplant recipients. METHODS: Between November 2005 and July 2008, 296 heart transplant recipients had a total of 864 IM assays performed at 2 weeks to 10 years post-transplant and were correlated with infection and rejection events that occurred within 1 month after IM testing. All patients received standard triple-drug immunosuppressive therapy with tacrolimus, mycophenolate mofetil and corticosteroids, without induction therapy. RESULTS: There were 38 infectious episodes and 8 rejection episodes. The average IM score was significantly lower during infection than steady state (187 vs 280 ng ATP/ml, p < 0.001). The average IM score was not significantly different during rejection when compared with steady state (327 vs 280 ng ATP/ml, p = 0.35). Interestingly, 3 of 8 rejection episodes were antibody-mediated rejections and had hemodynamic compromise and, for these, the mean IM score was significantly higher than for steady-state patients (491 vs 280 ng ATP/ml, p < 0.001). CONCLUSIONS: The non-invasive IM test appears to predict infectious risk in heart transplant patients. The association between high IM scores and rejection risk is inconclusive due to the small number of rejection episodes. Further studies with larger sample sizes for rejection episodes are required.