Impact of Advanced Therapies for Improving Survival to Heart Transplant in Patients with Hypertrophic Cardiomyopathy

Heart transplant has become an increasingly important option for patients with end-stage nonobstructive hypertrophic cardiomyopathy (HC). However, clinical details related specifically to the overall HC transplant experience remain sparse. We assessed outcomes of HC heart transplants, from 2002 to 2016, at Tufts Medical Center. Fifty-two nonobstructive severely symptomatic patients underwent evaluation at 47 ± 13 years; 11 (21%) declined or failed to qualify, most commonly because of co-morbidities (n = 7). Of the remaining 41 patients ultimately listed, 6 (15%) died of heart failure awaiting transplant (11%/year), 26 underwent transplant, and 9 remained active on the list. Survival rates on the waiting list depended on ≥1 treatment intervention: inotropic medications (n = 20), ventricular assist devices (n = 7), or implantable defibrillators terminating ventricular tachyarrhythmias (n = 7). Of the 26 transplanted patients, 24 survived for 4.8 ± 3.4 years (up to 12), including 23 who are currently alive. The survival rate 5 years post transplant is 92%. Compared with heart transplants for other cardiomyopathies, patients with HC had similar mortality while wait-listed and post transplant (p = 0.77 and 0.13, respectively). In conclusion, a large proportion of patients with HC considered for transplant ultimately received hearts and experienced excellent short- and long-term survival rates. The survival rate on the waiting list was directly attributable to major interventions: implantable cardioverter-defibrillators, inotropic drugs, and ventricular assist devices, and the perception that patients with HC have low wait-list mortality risk does not appear justified. Neither normal ejection fraction nor peak oxygen consumption > 14 ml/kg/min should exclude drug refractory severely symptomatic patients with HC from heart transplant consideration.