Heart Transplantation for Hypertrophic Cardiomyopathy: The Tufts Experience

Abstract

Background: Heart transplant has increasingly become an important treatment option for patients with a variety of end-stage cardiac diseases, including nonobstructive HCM. Details specifically related to the transplant experience in patients with HCM remain sparse, and current proposed allocation schemes may not adequately risk stratify this unique patient population. Therefore, we have evaluated our experience with heart transplantation in a large cohort of HCM patients. Methods: This analysis reviewed our 15-year experience with HCM patients evaluated for heart transplant, from 2002 to 2016, at the Tufts Medical Center, Hypertrophic Cardiomyopathy Institute and Cardiac Transplant Center. Results: Fifty-two patients underwent evaluation for transplant at 46 ± 13 years of age, 56% male, each in New York Heart Association functional class III/IV. Eleven of these 52 patients (21%) either declined or did not qualify, most commonly due to comorbidities that prohibited listing (n = 7). The remaining 41 patients were ultimately listed for transplant including 6 who did not meet traditional transplant criteria with peak VO2 > 14 ml/kg/min (and > 50% predicted for age and gender). Of the 41 patients, 6 (15%) died awaiting transplant due to heart failure, with 1- year mortality of 8.4%, 26 underwent heart transplantation, and 9 remain active on the transplant list. Extended survival to transplant in 28 patients (68%) was due to treatment interventions including ventricular assist devices (n = 7) or inotropic medications (n = 20), and 7 (of 33) with implanted defibrillators experienced appropriate device interventions for VT/VF (n = 7). Of the 6 patients listed with peak VO2 > 14 ml/kg/min, 4 required either inotropic medication (n = 3), or ventricular assist device (n = 1) for survival to transplant. Heart transplant was performed in 26, and 2 died within 30 days from primary allograft dysfunction, and 24 (92%) survived to 4.8 ± 3.4 years (range 6 months to 12 years). One patient died 9 years after transplant due to complications related to allograft vasculopathy, while the remaining 23 have survived to date, each in NYHA functional class I. Survival at both1 and 5 years post-transplant was 92%. Conclusions: Mortality in nonobstructive HCM patients listed for transplant is relatively high. A number of treatment interventions are necessary for HCM patients to survive to transplant including primary prevention ICDs and inotropic medications, and in select patients ventricular assist devices. Transplanted HCM patients have excellent short and long-term survival. In patients with nonobstructive HCM the severity of symptoms are not always supported by traditional heart transplant testing (i.e., peak VO2) and thereby the decision to offer transplant should be made on an individual patient basis.