Introduction and Background:
Arrhythmogenic ventricular cardiomyopathy (AVC) is a hereditable disorder characterized by fibro-fatty infiltration of the right ventricular myocardial wall. The purpose of this study was to describe the clinicopathologic phenotype of AVC in pediatric end-stage heart failure patients who underwent heart transplantation (HTx).
Hypothesis:
We hypothesized that AVC is misclassified in the young population who require heart transplant.
Methods:
We investigated 371 consecutive cases of primary pediatric (≤21 years) heart transplantation performed at Texas Children’s hospital between 1989 and 2018. Heart re-transplants were excluded from the study. Explanted hearts and tissue blocks were examined by a cardiac pathologist after HTx. Histological Diagnosis of AVC was based on the presence of major and minor diagnostic criteria according to the 2010 Revised Task Force Criteria.
Results:
Over half of the patients who underwent HTx had cardiomyopathy (212/371=57%) as the underlying primary diagnosis. After comprehensive histological evaluation of explanted hearts, 8 cases (8/212=3.8%) were diagnosed with AVC. Predominantly right ventricular disease was seen in 2/8 (25%), and biventricular involvement in 6/8 (75%) patients on pathological examination. Six out of 8 patients (6/8=75%) were misclassified, 4 as dilated cardiomyopathy, 1 as viral myocarditis, and 1 as restrictive cardiomyopathy. The median age at heart transplant (AVC cohort) was 11 years. Four of 8 (50%) were males. Six of 8 (75%) had a significant ventricular arrhythmia burden manifesting as non-sustained ventricular tachycardia requiring antiarrhythmic therapy. Genetic testing was undertaken in 3 of 8 (37.5%); all three were found to have pathogenic mutations in the PKP2 gene.
Conclusion:
Arrhythmogenic ventricular cardiomyopathy is often misclassified in the young population who require heart transplant. Pediatric dilated and restrictive cardiomyopathy phenotypes with end-stage heart failure waitlisted for a heart transplant (HT) who have a significant ventricular arrhythmia burden should be investigated for AVC.
Home Inotrope Program for Patients with End-Stage Heart Failure Awaiting Heart Transplant
