Abstract
OBJECTIVE: Syndromic conditions are frequently associated with congenital heart disease (CHD). Their distribution, recognition and prognostic impact in adults with CHD (ACHD) remain poorly characterised due to limited assessment beyond childhood. METHODS: We retrospectively analysed 9826 patients with ACHD from a tertiary ACHD centre. Syndromic conditions were identified from clinical records and categorised as chromosomal, single-gene or other syndromes. Clinical characteristics, comorbidities and CHD complexity were compared between syndromic and non-syndromic patients. Multivariable Cox regression was used to evaluate associations with all-cause mortality. RESULTS: Of 9826 patients, 1069 (10.9%) had a syndromic diagnosis. Marfan syndrome (4.1%) and Down syndrome (3.6%) were the most common, followed by Noonan syndrome (0.7%) and 22q11.2 deletion syndrome (0.7%). Syndromic patients were younger (median 34 vs 39 years), had higher rates of pulmonary arterial hypertension (15% vs 5.9%) and sleep apnoea (7.4% vs 2.8%), but fewer traditional cardiovascular risk factors. Down syndrome clustered with atrioventricular septal defect and 22q11.2 deletion with conotruncal defects. In Tetralogy of Fallot, 4.3% had 22q11.2 deletion, mostly diagnosed in childhood; among those without prior diagnosis, most were neither clinically suspected nor tested in adulthood, suggesting under-recognition compared with paediatric cohorts. A syndromic diagnosis was independently associated with higher all-cause mortality (HR 2.06, 95% CI 1.76 to 2.42, p<0.001). CONCLUSIONS: We present herewith our institutional ACHD data showing that approximately 1 in 10 patients had a syndromic condition, which was clinically relevant in many respects, cardiovascular or other, including overall mortality. We submit that improved recognition and expanded access to genetic screening may provide additional information relevant to risk stratification and long-term outcome in this growing patient population.