Objective: Maternal anti-SSA/Ro or anti-SSB/La antibodies are associated with neonatal lupus erythematosus syndrome (NLES), especially congenital heart block (CHB), which may be associated with severe endocardial fibroelastosis (EFE) and dilated cardiomyopathy (DCM). A few reports have described severe EFE without CHB associated with anti-SSA/Ro antibodies, with a poor prognosis. EFE has also been observed in biopsies of DCM that had been considered idiopathic. These points, considered in association with 5 unusual cases of mild EFE, led us to consider the relationship between underrecognized cases of isolated autoantibody-associated EFE and DCM that had been considered idiopathic.
Methods: We analyzed 5 cases of EFE diagnosed in utero (n = 4) or after birth (n = 1). In 3 cases, maternal antibody status was discovered because of the EFE diagnosis.
Results: Endomyocardial hyperechogenicity predominated in the left atrium (n = 3) and mitral annulus (n = 3). No left-heart dysfunction was observed. Two mothers were treated with betamethasone. One mother chose to have a therapeutic abortion, and EFE was confirmed at autopsy. Electrocardiograms at birth (n = 4) did not show CHB. Other manifestations of NLES were present in all cases. One child had right ventricular hypoplasia and underwent a partial cavopulmonary anastomosis. At last followup (4-7 yrs), the other 3 children had normal heart function, and echocardiography showed a normal heart (n = 2) or mild persistent EFE (n = 1).
Conclusion: Middle-term prognosis of isolated autoantibody-associated EFE may be better than previously reported, although the longterm prognosis remains unknown. We hypothesize that a fetal insult can lead to DCM.