ABSTRACT
Complex congenital heart disease (CHD) in each of dichorionic diamniotic (DiDi) twin pairs is extremely rare and has not been well characterized. Four DiDi twin pairs were included in this multi-institutional case series. The congenital cardiac abnormalities noted included tetralogy of Fallot (ToF) with pulmonary atresia and collaterals (n = 1), ToF with absent pulmonary valve (n = 1), ToF (n = 2), discontinuous right pulmonary artery (RPA) (n = 1), tricuspid atresia (TA) with normally related great arteries and pulmonary valve stenosis or atresia (n = 2) and coarctation of aorta (CoA) with bicuspid aortic valve (BAV) and borderline left-sided structures (n = 1). Genetic testing was obtained on seven of the eight twins but did not reveal any causal abnormality. A comprehensive review of literature yielded another 8 DiDi twin pairs with complex CHD. The CHD noted in these twin pairs included ToF (n = 2), CoA (n = 4), corrected transposition of great arteries (ccTGA) (n = 2), truncus arteriosus (n = 2), complete common atrioventricular canal (CCAVC) (n = 2), hypoplastic left heart syndrome (HLHS) (n = 2), Shone's complex (n = 1), and hypoplastic right heart syndrome (HRHS) (n = 1). Limited genetic testing was obtained on 4 of these twins and revealed trisomy 21 in a twin pair. Conotruncal abnormalities (42%), CoA (21%), and abnormalities of the right ventricle, the right ventricular outflow tract and pulmonary arteries (17%) are more prevalent in DiDi twins with complex CHD. Clustering of these abnormalities suggests a possible genetic basis; however, genetic testing was obtained on eleven of the twins, and except for trisomy 21 in a twin pair both of whom had CCAVC, did not reveal any causal abnormality. A major direct genetic contribution is therefore unlikely and like other CHD, the underlying etiopathological basis is likely multifactorial.
ABSTRACT
Background Neurocognitive impairment is a common complication of congenital heart disease (CHD) as well as acquired cardiovascular disease. Data are limited on neurocognitive function in adults with CHD (ACHD). Methods and Results A total of 1020 individuals with mild-to-moderate ACHD and 497 987 individuals without ACHD from the volunteer-based UK Biobank study underwent neurocognitive tests for fluid intelligence, reaction time, numeric memory, symbol-digit substitution, and trail making at enrollment and follow-up. Performance scores were compared before and after exclusion of preexisting stroke or coronary artery disease as measures of cerebro- and cardiovascular disease. Individuals with ACHD had significantly poorer performance on alpha-numeric trail making, a measure of visual attention and cognitive flexibility, spending 6.4 seconds longer on alpha-numeric trail making (95% CI, 3.0-9.9 seconds, P=0.002) and 2.5 seconds longer on numeric trail making (95% CI, 0.5-4.6 seconds, P=0.034), a measure of visual attention and processing speed. The ACHD cohort had modestly lower performance on symbol-digit substitution, a measure of processing speed, with 0.9 fewer correct substitutions (95% CI, - 1.5 to - 0.2 substitutions, P=0.021). After excluding preexisting stroke or coronary artery disease, individuals with ACHD continued to show poorer performance in all 6 domains (P=NS). Conclusions Individuals with mild-to-moderate ACHD had poorer neurocognitive performance, most significantly in tests of cognitive flexibility, analogous to deficits in children with CHD. These differences appear to be driven by increased burden of cerebro- and cardiovascular disease among individuals with ACHD.
