Heart Transplant- an unexpected success story
The median survival after a heart transplant is currently an astounding 13 years.
Nevertheless, chronic rejection, 8% in the first year and 32% after 5 years may occur after transplantation, this may be due in part to poor compliance with immunosuppressive agents.
Cardiology
InShort
by Justin Cole, M.D. and David Spielvogel, M.D.
Heart transplant is a procedure indicated for severe, irreversible cardiac disease, often in relatively young patients. It consists of replacement of the de novo heart with a compatible donor allograft.
Indications
Indications for heart transplant include end-stage heart failure with objective, impaired functional capacity despite optimal medical management; recurrent, life-threatening arrhythmias refractory to medical therapy; intractable angina refractory to medicaltherapy and other interventions; primary cardiac tumors; and hypertrophic or restrictive cardiomyopathy not amenable to standard surgical intervention (i.e. myomectomy).
Contraindications
Contraindications for heart transplant include: severe, irreversible pulmonary hypertension; severe peripheral vascular disease; late-stage diabetes mellitus withorgan failure/irreversible organ damage; severe, irreversible liver, kidney, or pulmonary disease (but may be amenable to multi organ transplant [i.e. heart-kidney transplant]); active tobacco or illicit drug use; active infections; body mass index < 15 or > 40, or age> 70 years (relative contraindications).
Heart Transplant Treatment and Recommended Follow-Up
Before heart transplant, all patients must receive pneumococcal and influenza vaccinations (and hepatitis B vaccine, if not immune). Immediately following transplant, all patients must receive triple therapy consisting of glucocorticoids, calcineurin inhibitors, and antiproliferative agents. Patients are progressively weaned off glucocorticoids over 3-6 months. Prophylaxis should be immediately provided for Pneuomocystic carinii (with trimethoprim/sulfamethoxazole),herpes simplex virus (with acyclovir, valacyclovir), and oral candidiasis. Valganciclovir should be used in cytomegalovirus (CMV) -seropositive individuals. Acute graft rejection (humoral type)should be treated with high-dose intravenous (IV) corticosteroids with plasmapheresis and low-dose IV immunoglobulin. Acute graft rejection (cell-mediated type) should be treated with high-dose IV corticosteroids. Anti-thymocyte antibodies should be added if there is hemodynamic compromise and/or no improvement within the first days of steroid therapy.
Cardiac allograft vasculopathy (CAV) is a common cause of chronic graft rejection.Treatment/prophylaxis includes statins, angiotensin-converting enzyme inhibitors, and calcium-channel blockers. Ganciclovir prophylaxis also helps prevent CAV progression secondary to CMV viral infection. Outcomes for advanced CAV are poor, and retransplantation is the only definitive treatment.
Prognosis
Median survival after heart transplant is ~13 years.
Heart Transplant Complications
Graft Rejection: Hyperacute graft rejection occurs within minutes to hours of heart transplant and is rare with current human leukocyte antigen and blood-typing techniques. Acute rejection may occur within weeks to years and is diagnosed by myocardial biopsy (usually performed on a regular basis). It may be caused by poor compliance with immunosuppressive agents. Chronic rejection occurs months to years after transplantation and leads to irreversible damage to the allograft, occurring in 8% in the first year and 32% after 5 years.
Coronary angiography and/or Dobutamine stress echocardiography is often used to screen patients for allograft vasculopathy.
Isolated right ventricular failure is more common than biventricular failure in heart transplant patients due to pulmonary hypertension. Most patients have a reversible component that resolves shortly after transplant. A fixed component may persist.
Tricuspid regurgitation occurs in 19%-84% of all transplant patients. Patients can typically be managed conservatively with diuretics. Some degree of mitral regurgitation occurs in ~ 50% of all patients in the postoperative period and is typically asymptomatic.
Hypotension occurs in some patients postoperatively secondary to systemic vasodilation. All of these patients should be worked up for possible sepsis. These patients may respond to alpha agonists.
Sepsis is a major cause of early morbidity and mortality in the transplant patient, accounting for roughly 20% of deaths within the first year of surgery.
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References
Birati, EY, Rame JE. Post-heart transplant complication. CritCare Clin.2014;30:629-637.
Initial post December 2020