Hyperacute rejection in heart allografts. Case studies

Early Graft Dysfunction Following Heart Transplant: Prevention and Management

Heart transplant can be considered as the “gold standard” treatment for end-stage heart failure, with nearly 5.7 million adults in the United States carrying a diagnosis of heart failure. According to the International Society for Heart and Lung Transplantation registry, nearly 3300 orthotopic heart transplants were performed in 2016 in North America. In spite of significant improvements in overall perioperative care of heart transplant recipients for the past few decades, the risk of 30-day mortality remains 5% to 10%, primarily related to early failure of the allograft. Early graft dysfunction (EGD) occurs within 24 hours after transplant, manifesting as left ventricular dysfunction, right ventricular dysfunction, or biventricular dysfunction. EGD is further classified into primary and secondary graft dysfunction. This review focus on describing overall incidences of EGD, potential risk factors associated with EGD, perioperative preventive measures, and various management options.

Update on cardiac transplantation pathology

CONTEXT

The endomyocardial biopsy is the mainstay for monitoring acute allograft rejection in heart transplantation. Objective and accurate assessment of cellular and humoral types of rejection is important to optimize immunosuppressive therapy, avoid therapeutic complications, and improve patient outcome. The grading system for evaluation of heart transplant biopsies published in 1990 was revised in 2004 after more than a decade of implementation.

OBJECTIVE

In this review, we focus on a practical approach to the evaluation of human heart transplant biopsies as diagnostic surgical pathologic specimens. We discuss the revised International Society of Heart and Lung Transplantation working formulation.

DATA SOURCES

We reviewed pertinent literature, incorporating ideas and vast experience of participants in various work groups that led to the revision of the 1990 grading system.

CONCLUSIONS

The grading system for cellular rejection is presented with detailed light microscopic morphology and comparison of the 1990 and 2004 International Society of Heart and Lung Transplantation working formulations. We show how the pathologic recognition of cellular rejection and antibody-mediated rejection has evolved. We emphasize the interpretation of immunostains for complement components C4d and C3d in the diagnosis of antibody-mediated rejection. Evidence of regulation of complement activation in human heart transplant biopsies is presented in this context. We also discuss the pitfalls, caveats, and artifacts in the interpretation of allograft endomyocardial biopsies. Lastly, we discuss the pathology of human cardiac allograft vasculopathy in practical detail.

Previous open heart operation: a contribution to impaired outcome after cardiac transplantation?

BACKGROUND

There is still debate about whether previous cardiac operations are a risk factor for patient outcome after cardiac transplantation. As waiting lists for cardiac transplantation increase, adverse outcome criteria should be identified.

METHODS

To assess this problem, we retrospectively analyzed 53 patients with previous cardiac operations before heart transplantation and compared them with 53 control patients matched for sex and age. Patient groups were analyzed regarding their preoperative, intraoperative, and postoperative variables and survival.

RESULTS

Ischemic times were comparable in both groups, but the duration of the operation was significantly longer in the study group (206.5 +/- 62.5 minutes, versus 156.0 +/- 36.7 minutes in controls; p < 0.05). In addition, postoperative blood loss was greater for the patients with previous cardiac operations (1,360 +/- 260 mL, versus 730 +/- 310 mL for controls; p < 0.01). Postoperatively, the rate of rejection episodes and the incidence of graft atherosclerosis were comparable within the first 2 years. However, survival was significantly reduced in the study group (60.1%) after 4 years (versus 83.1% for controls; p < 0.05).

CONCLUSIONS

Heart transplantation in patients with previous cardiac operations will lead to an impaired overall outcome. In addition, these patients have more postoperative complications.

Early cardiac allograft failure after orthotopic heart transplantation

Early cardiac graft failure has been reported to occur in 4-25% of patients undergoing orthotopic heart transplantation. To further elucidate the characteristics and prognosis of patients with graft failure, we retrospectively identified 10 patients from a series of 212 consecutive recipients with catastrophic graft dysfunction in the absence of acute cellular rejection, right ventricular failure secondary to pulmonary hypertension and technical factors. We present a case report and the experience from one transplant center, a review of the literature and possible strategies for the management of early graft failure. Mean onset of graft failure was 6.5 days (range intraoperative to 23 days). Multivariable analysis revealed a longer total ischemic time in patients with early graft dysfunction (200 +/- 14 vs. 166 +/- 4 min). No episodes of hyperacute rejection were observed. Pathologic changes noted on biopsy or autopsy included ischemia in 9 and vascular rejection in 1. The mortality at 60 days was 50%. Early use of aggressive mechanical and pharmacological support is described and appears to be important for graft salvage.