Cardiac Transplantation
Indications and evaluation
Transplant candidates have end-stage HF despite optimized therapy, limited survival, and acceptable end-organ function. Evaluation includes right heart catheterization, assessment of pulmonary vascular resistance (PVR), sensitization (PRA/virtual crossmatch), infection and malignancy screening, psychosocial assessment, and nutritional status. Mechanical support can bridge patients to transplant.
Pulmonary vascular resistance
Fixed pulmonary hypertension is a major contraindication because the denervated donor right ventricle may fail against high resistance. Ideal PVR is <3 Wood units; PVR >5 Wood units despite vasodilator challenge (or transpulmonary gradient >15 mmHg) generally precludes orthotopic transplant. Reversibility testing with nitroprusside, milrinone, or inhaled nitric oxide is essential.
Post-transplant care
Immunosuppression includes induction and maintenance (calcineurin inhibitor, antimetabolite, corticosteroid). Rejection may be cellular or antibody-mediated; surveillance includes echocardiography, endomyocardial biopsy when indicated, and donor-specific antibody testing. Complications include infection (CMV), allograft vasculopathy, malignancy (PTLD, skin cancer), renal dysfunction, and metabolic disease. The denervated heart has resting tachycardia, no anginal warning, and relies on preload; avoid agents that impair sinus node function or precipitate vasodilation.
Traps
Do not list a patient with irreversible PVR simply because EF is low. Echo-estimated RVSP cannot substitute for invasive hemodynamics. Distinguish primary graft dysfunction from rejection.
Worked example
A 55-year-old with NICM, LVEF 20%, and PVR 6 Wood units unresponsive to nitroprusside is not an orthotopic transplant candidate because of right-heart failure risk; consider LVAD or reevaluation. Rule of thumb: PVR <3 Wood units favorable; >5 and fixed, contraindicated.