Outcomes of adults with restrictive cardiomyopathy after heart transplantation.
BACKGROUND
Restrictive cardiomyopathy (RCM) represents a spectrum of disorders with a common physiology but divergent etiologies. RCM commonly leads to progressive heart failure and the need for heart transplantation (HTx). Pediatric RCM is a more homogeneous disorder with post-HTx outcomes comparable to those for non-RCM patients. However, post-HTx outcomes in adult RCM patients have not been studied to date.


METHODS
Demographic, clinical and survival outcomes of 38,190 adult HTx-only recipients from 1987 to 2010 were acquired from the registry of the United Network of Organ Sharing. The study population included 544 RCM patients (1.4%) and 37,646 non-RCM patients (98.6%). RCM diagnoses included idiopathic (n = 227, 42%), amyloid (n = 142, 26%), sarcoid (n = 81, 15%), radiation/chemotherapy (XRT) (n = 35, 6%) and other (n = 59, 11%).


RESULTS
Follow-up began at the time of HTx (74±64 months). During the follow-up period, 224 (41%) patients in the RCM group died, whereas 18,791 (50%) in the non-RCM group died. Crude 1-, 5- and 10-year survival for RCM patients was 84%, 66% and 45%, and for non-RCM patients was 85%, 70% and 50%, respectively. The overall unadjusted hazard ratio of RCM vs non-RCM for all-cause mortality was 1.07 (confidence interval [CI] 0.93 to 1.22). Multivariate Cox proportional hazards regression analysis yielded a hazard ratio of 1.06 (CI 0.91 to 1.25). RCM subgroup analysis showed decreased survival at 1, 5 and 10 years in the XRT (71%, 47% and 32%) and amyloid (79%, 47% and 28%) patient groups. The unadjusted hazard ratio for the XRT and amyloid subgroups vs RCM for all-cause mortality was 1.81 (p = 0.002) and 1.85 (p = 0.0004), respectively.


CONCLUSIONS
Outcomes for RCM patients post-HTx are comparable to those of non-RCM patients. However, RCM subgroup analysis suggests increased mortality for XRT and amyloid subgroups. Further analysis is warranted to understand the contributing factors.
Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles.
Eugene C
EC
DePasquale
Khurram
K
Nasir
Daniel L
DL
Jacoby
D000328:Adult; D000686:Amyloidosis / Q000150:complications; D002313:Cardiomyopathy, Restrictive / Q000139:chemically induced / Q000209:etiology / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011878:Radiotherapy / Q000009:adverse effects; D012507:Sarcoidosis / Q000150:complications; D016896:Treatment Outcome