Cardiac Transplantation Complications

Basics

Description

  • Cardiac transplant recipients are a unique population with increased risk for cardiac ischemia, heart failure, as well as general risks as an immunocompromised host
  • 1,900–2,300 cardiac transplants per year in the U.S.
  • 1-yr survival 85–90%; 5-yr survival ∼75%
  • Pediatric transplants increased 37% between 2004–2015
  • Typical immunosuppressive therapy to control rejection is a “triple-drug” regimen often including steroids
  • Evaluation for rejection:
    • Frequent biopsies are used initially
    • Echocardiography often used in children
  • Complications occur most commonly in the first 6 wk after cardiac transplantation

Geriatric Considerations
  • The proportions of elderly patients on the transplant list, and those receiving transplants are increasing
  • Due to changes in immune system with age, elderly transplant recipients are at increased risk of life-threatening infections, and acute rejection


Pregnancy Considerations
  • Pregnancy after cardiac transplant is becoming more common. Between 1988–2010, 63 women received either heart or heart–lung transplants. They have reported 108 pregnancies, all progressing to live births
  • Most common complications include hypertension, pre-eclampsia, and rejection
  • Physiologic changes that occur with pregnancy do not relate to increased rate of heart failure in transplant patients
  • Special attention should be paid to these patients regarding rejection and infection given their immunosuppression

Etiology

  • Rejection:
    • Hyperacute rejection:
      • Occurs within minutes of transplantation
      • Rare, due to ABO or other graft/host major incompatibility
      • Aggressive and immediately fatal to graft
    • Acute rejection:
      • Lymphocyte infiltration and myocyte destruction
      • Most common in the first 6 wk
      • May occur at any time
      • 23% incidence in first year post transplant
    • Chronic rejection:
      • Fibrosis and graft vascular disease
      • Long-term complication
      • Incompletely understood etiology
      • No effective therapy
  • Cardiac allograft vasculopathy:
    • Analogous to accelerated coronary artery disease in native hearts
    • Limits long-term survival, leading cause of mortality after 1 yr
  • Immune-mediated atherosclerosis:
    • Form of chronic rejection
  • Infections:
    • First month:
      • Bacterial infections are the most common cause of mortality during this high-risk time period
      • Pneumonia (Pseudomonas, Legionella, other gram-negative organisms)
      • Mediastinitis
      • Wound infection
      • UTI
    • First yr:
      • Opportunistic and conventional infections
      • Cytomegalovirus (CMV)
      • Herpes simplex virus (HSV)
      • Legionella
      • Fungal infections
      • Pneumocystis carinii
  • Medication toxicity
    • Cyclosporine, neoral (second-generation cyclosporine), tacrolimus:
      • Nephrotoxicity (30% incidence)
      • Hepatotoxicity
      • Neurotoxicity
      • Hyperlipidemia, diabetogenic
    • Azathioprine, mycophenolate mofetil:
      • Bone marrow suppression
      • Leukopenia
    • Sirolimus:
      • Hyperlipidemia
      • Wound healing
    • Steroids:
      • Osteoporosis
      • Cushing disease
  • Neoplasms:
    • Secondary to immunosuppression
    • 10–100 times more common vs. general population
    • Skin and lip cancer
    • Lymphomas
    • Kaposi sarcoma
    • Solid organ neoplasms

Pediatric Considerations
  • If the patient is not on steroids, bacteremia risk is similar to that in the general population
  • High incidence of pneumonia
  • Patients on steroids may not show meningeal signs

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