Syndromic and Non-Syndromic Patients with Repaired Tetralogy of Fallot: Does It Affect the Long-Term Outcome?

Background: The impact of genetic syndromes on cardiac magnetic resonance imaging (cMRI) parameters, particularly on right and/or left ventricular dysfunction, associated with clinical parameters following the repair of Tetralogy of Fallot (rToF) is not well known. Therefore, this study aimed to assess the differences in clinical, surgical, and cMRI data in syndromic and non-syndromic rToF patients. Methods: All syndromic rToF patients undergoing a cMRI without general anesthesia between 2010 and 2020 who were able to match with non-syndromic ones for birth date, sex, type of surgery, timing of cMRI, and BSA were selected. Demographic, clinical, surgical, MRI, ECG, and Holter ECG data were collected. Results: A total of one hundred and eight rToF patients equally subdivided into syndromic and non-syndromic, aged 18.7 +/- 7.3 years, were studied. Del22q11.2 and Down syndrome (DS) were the most frequent syndromes (42.6% and 31.5%, respectively). Regarding the cMRI parameters considered, left ventricular (LV) dysfunction (LVEF < 50%) was more frequently found in syndromic patients (p = 0.040). In addition, they were older at repair (p = 0.002) but underwent earlier pulmonary valve replacement (PVR) (15.9 +/- 5.6 vs. 19.5 +/- 6.0 years, p = 0.049). On multivariate Cox regression analysis, adjusted for age at first repair, LV dysfunction remained significantly more associated with DS than del22q11.2 and non-syndromic patients (HR of 5.245; 95% CI 1.709-16.100, p = 0.004). There were only four episodes of non-sustained ventricular tachycardia in our cohort. Conclusions: Among the cMRI parameters commonly taken into consideration in rToF patients, LV dysfunction seemed to be the only one affected by the presence of a genetic syndrome. The percentage of patients performing PVR appears to be similar in both populations, although syndromic patients were older at repair and younger at PVR. Finally, the number of arrhythmic events in rToF patients seems to be low and unaffected by chromosomal abnormalities.