Cognitive Function in Adults with Congenital Heart Disease and Its Association with Cyanosis Duration: A Pilot Study in Adults with Congenital Heart Disease

Objectives: It is often assumed that adults with congenital heart disease (ACHD) have an impairment regarding their cognitive function. In particular, it seems reasonable to assume that cyanosis may have potential impact on cognitive function in adulthood. However, currently, there is no data regarding cognitive function formally assessed by standardized intelligence tests in ACHD patients. This study assesses the cognitive function in ACHD patients and its association with cyanosis duration.

Methods: Seventy ACHD patients (female n = 31 [44.3%]; mean age at assessment 35.1 ± 13.9 years; cyanotic congenital heart disease [CHD] n = 49 [70.0%] with a cyanosis duration of 142.6 ± 186.8 months) underwent the Wechsler Intelligence Scale for adults (fourth edition, German version)—a well-established assessment of cognitive function in adults—as inpatients between March 2017 and January 2018. In this test, impairment is defined as an intelligence quotient (IQ) achieved which is lower than 1 standard deviation (SD) of the norm.

Results: The mean full scale IQ (FSIQ) achieved by the patients was 96.0 ± 12.2 points. Regarding the subgroups, the patients achieved 98.5 ± 12.1 IQ points (IQp) in verbal comprehension, 97.3 ± 14.2 IQp in working memory, 95.3 ± 13.2 IQp in logical thinking, and 96.7 ± 12.3 IQp in processing performance. Compared with the norm standard (Ø100 IQp ± 1 SD), no impairment in cognitive function was present in ACHD patients. The comparison in patients with acyanotic CHD (n = 21, achieved 93.1 ± 10.8 FSIQ points) and patients with cyanotic CHD (n = 49, achieved 97.2 ± 12.7 FSIQ points) shows no difference between the groups (p = 0.214). In a regression model, no significant association between full scale intelligence and cyanosis duration was found (p = 0.512).

Conclusion: Contrary to the general assumption, ACHD patients showed no significant impairment in cognitive function compared with the norm. Furthermore, there seem to be no difference in cognitive function outcomes with regard to specific CHD conditions (cyanotic/acyanotic) in ACHD patients in this study. Studies in larger cohorts are needed to assess the impact of cyanosis and other possible confounding factors on cognitive function in this growing patient population.

No conflict of interest has been declared by the author(s).