Survival after cardiac transplantation in patients with hypertrophic cardiomyopathy
Department of Medicine, Division of Preventive and Behavioral Medicine
Adult; Cardiomyopathy, Hypertrophic; Chi-Square Distribution; Comorbidity; Female; Heart Transplantation; Humans; Logistic Models; Male; Middle Aged; Prevalence; Prognosis; Proportional Hazards Models; Registries; Survival Rate; Treatment Outcome; United States
Cardiology | Cardiovascular Diseases
BACKGROUND: Heart transplant is a treatment option for selected patients with hypertrophic cardiomyopathy (HCM). However, the prevalence, clinical profile, and outcome of this subgroup of HCM patients are uncertain. Therefore, we sought to determine the occurrence, clinical characteristics, and prognosis of HCM patients who underwent cardiac transplantation in the United States during a 15-year period.
METHODS AND RESULTS: Demographic, clinical, and survival outcomes of 26 706 adult (age >/=18 years), heart-only transplant recipients between January 1990 and December 2004 were acquired from the United Network of Organ Sharing Registry. Pretransplant diagnoses were classified as follows: HCM (n=303, 1%) and non-HCM (26 403, 99%), comprising 3 patient subgroups: (1) ischemic cardiomyopathy (n=14 308, 54%), (2) dilated cardiomyopathy (n=11 760, 44%), and (3) restrictive cardiomyopathy (n=335, 1%). Study follow-up began at the time of heart transplant and was 76+/-44 months (mean+/-SD) among survivors. The 1-, 5-, and 10-year overall transplant survival for HCM patients was 85%, 75%, and 61%, respectively, with a trend toward greater survival compared with that of non-HCM transplant patients (82%, 70%, and 49%, respectively; log-rank test, P=0.05). However, propensity-matched, covariate-adjusted, Cox regression model analysis showed better survival over time (P<0.01) among the HCM patients. When HCM posttransplant survival was compared with that in each of the non-HCM patient subgroups, HCM patients had more favorable survival than did those transplanted for ischemic cardiomyopathy (P=0.02). In contrast, HCM posttransplant survival did not differ from that of patients transplanted for restrictive (P=0.08) or dilated (P=0.25) cardiomyopathy.
CONCLUSIONS: HCM patients compose a small subset (1%) of the overall population of patients who undergo heart transplantation in the United States. Nonetheless, survival after transplant among HCM patients is comparable to that of patients transplanted for non-HCM cardiovascular diseases, with possible enhanced survival over time.