Chapter 72: Cardiac Transplantation
Which of the following is not an indication for heart transplantation?
A. NYHA functional class IIIb–IV symptoms despite optimal medical and device therapy
B. VO2 max of ≤ 12 to 14 mL/kg/min and/or VO2 max < 50% predicted and/or VE/VCO2 slope > 35 on cardiopulmonary exercise stress testing (CPET)
C. Cardiogenic shock not expected to recover
D. Intractable ventricular arrhythmias, uncontrolled with standard antiarrhythmic, device, or ablative therapy
E. Congenital heart disease with severe, fixed pulmonary hypertension
The answer is E. (Hurst’s The Heart, 14th Edition, Chap. 72) The goal of a heart transplant evaluation is to determine if (1) the patient’s cardiac status is limited enough, on optimal medical therapy, to benefit from heart transplantation (ie, “sick enough”) (options A, B, and C); (2) the patient does not have comorbidities that would preclude heart transplantation (ie, “well enough”); and (3) the patient demonstrates compliance and possesses adequate social support (“can adapt to new transplant lifestyle”). The cardiopulmonary exercise stress test measures maximal oxygen consumption (VO2 max), which is proportional to cardiac output. Patients with a peak VO2 of more than 14 mL/kg/min have 1- and 2-year survival rates that are comparable or better than those achieved with transplantation, and these patients should be managed medically and should undergo serial exercise testing.1,2 In the early years of heart transplantation, it was discovered that a normal donor right ventricle (RV) cannot increase its external workload acutely to overcome elevated pulmonary vascular resistance (PVR), resulting in acute RV failure and cardiogenic shock postoperatively.3 Elevated PVR remains a strong risk factor for RV failure and early postoperative mortality. A pulmonary artery systolic pressure above 50 to 60 mm Hg, a PVR value above 5 Wood units, or a transpulmonary gradient above 15 to 20 mm Hg is usually considered prohibitive of successful heart transplantation (option E).
You are contacted to evaluate a potential heart as a donor for transplantation. Which of the following are favorable donor characteristics?
A. Cardiac index > 2.4 L/min·m2
B. Left ventricular (LV) wall thickness > 13 mm
C. Donor-recipient body size match (usually within 20% to 30% of height and weight)
E. Both A and C are correct
The answer is E. (Hurst’s The Heart, 14th Edition, Chap. 72) To be considered suitable donors for cardiac transplantation, brain-dead individuals must meet certain minimum criteria. Most cardiac donors are younger ...