Cardiac Transplantation Complications

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

• 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 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

• 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