Correlation Between Total Repair Timing and Late Aortic Root Dilatation in Repaired Tetralogy of Fallot

Patterns of Aortic Dilation in Tetralogy of Fallot: An Analysis of 100 Fetal Echocardiograms Compared With Matched Controls

Background Although aortic dilation is common in tetralogy of Fallot (TOF), its progression and risk of dissection are not well understood. The mechanism of dilation is primarily attributed to increased flow in utero; an alternative is unequal septation of the truncus arteriosus resulting in a larger aorta and inherently hypoplastic pulmonary artery (PA). If the latter is true, we hypothesize the aorta to PA ratio in TOF is stable throughout gestation, and sums of great artery dimensions are similar to controls. Methods and Results We performed a single-center retrospective study of fetuses with TOF (2014-2020) and matched controls. We compared sums of diameters, circumferences, and cross-sectional areas of the aorta and PA and evaluated the aorta to PA ratio across gestation in 2 TOF subtypes: pulmonary stenosis and atresia (TOF-PA). There were 100 echocardiograms with TOF (36% TOF-PA) with median gestational age of 31 weeks (interquartile range 26.5-34.4) and median maternal age of 34 years (interquartile range 30-37). There were no differences in sums of great artery dimensions between TOF-pulmonary stenosis and controls. In TOF-PA, sums were significantly lower than controls (P values <0.01). The aorta to PA ratio was stable throughout gestation (Pearson's r=0.08 [95% CI, -0.12 to 0.27], -0.06 [95% CI, -0.25 to 0.14]). Conclusions The aorta in fetal TOF is large but grows proportionally throughout gestation, with sums of great artery dimensions similar to controls. TOF-PA appears distinct from TOF-pulmonary stenosis (with smaller sums), warranting further investigation. In conclusion, our findings suggest an intrinsic developmental mechanism contributes to aortic dilation in TOF.

Aorta Dilatation in Unrepaired Tetralogy of Fallot

Background Aortic root dilation is an increasingly recognized feature in repaired tetralogy of Fallot (TOF) patients. However, the dilation at the aortic root and ascending aorta in unrepaired TOF is rarely studied. This study aims to confirm whether aortic dilation is a common feature in unrepaired TOF and investigate the factors attributed to aortic dilation. Methodology Patients with an echocardiographic diagnosis of TOF undergoing computed tomography angiography were retrospectively studied. Diameters and z scores of aortic annular (Ao1), aortic sinotubular junction (Ao2), ascending aorta (Ao3), and distal transverse aortic arch (Ao4) were measured. Preoperative body surface area (BSA), hemoglobin (Hb), hematocrit (HCT), arterial oxygen saturation (SaO2), and platelet (PLT) count were recorded. Results A total of 101 TOF patients aged 6.8 ± 9.5 years were included in this study, whose mean BSA (m2), Hb (g/L), HCT, SaO2 (%), and PLT (109/L) were 0.7 ± 0.4, 162.1 ± 3.8, 0.5 ± 0.1, 85.1 ± 9.3, and 238.1 ± 101.1, respectively. The mean z score of Ao1, Ao2, Ao3, and Ao4 were 10.3 ± 3.5, 4.7 ± 2.9, 4.0 ± 2.7, and 4.1 ± 2.4, respectively. Age and BSA were positively correlated with the z scores of Ao1 and Ao2. Preoperative Hb and HCT were positively correlated with the z scores of Ao1, Ao2, Ao3, and Ao4. Preoperative SaO2 and PLT were negatively correlated with the z scores of Ao1, Ao2, Ao3, and Ao4. Conclusions Aortic dilation is common in unrepaired TOF patients. The dilation of different levels of the aorta was correlated with age, BSA, preoperative Hb, HCT, SaO2, and PLT.

Ten-year follow-up of dilatation of aortic structures in Fallot-type anomalies

OBJECTIVES

Dilatation of the aortic root structures or ascending aorta is often observed in patients with Fallot-type anomalies. We aimed to determine the dilation rate of the aortic structures and investigate strategies for managing this phenomenon.

METHODS

In this retrospective study, we enrolled 66 out of 801 patients who underwent corrective surgery for Fallot-type anomalies (tetralogy of Fallot [TOF] and Fallot-type double outlet right ventricle [DORV]) between 2004 and 2020. These 66 patients had follow-up cardiac computed tomography (CT) angiography images taken at least 5 years after the initial CT study. We analyzed the diameters and aortic cross-sectional area/height ratio (AH) of the aortic annulus, sinus of Valsalva, sinotubular junction, and ascending aorta between the initial and follow-up CT scans. "Dilatation" was defined as a z-score over 2 for each aortic structure.

RESULTS

The median age at the initial and follow-up CT scans was 5.9 years (interquartile range [IQR]: 0.4 ~ 12.4) and 15.9 years (IQR 9.3 ~ 23.4), respectively. The median CT interval (from initial to latest CT) was 9.5 years (IQR 6.6 ~ 12.0). The sinus of Valsalva exhibited the most significant dilation (32.8 mm at follow-up CT) over the study period. The AH ratio increased significantly in all four aortic structures. The patient's age was significantly associated with higher AH in the follow-up CT. Aortic dilatation was present in 74.2% of patients at the initial CT and increased to 86.4% at the follow-up CT.

CONCLUSION

In Fallot-type anomalies, the AH ratio of aortic root structures significantly increased over an average period of approximately 9.5 years. The number of patients diagnosed with aortic dilatation also increased. Based on our observations in this study, these patients' group should be considered for more frequent follow-up examinations, as significant dilatation could occur in their mid-20 s.

Proximal Aortic Dilatation and Pulmonary Valve Replacement in Patients with Repaired Tetralogy of Fallot: Is There a Relationship? A Cardiac Magnetic Resonance Imaging Study

Aortopathy is a known complication whose incidence is growing within the population of tetralogy of Fallot (TOF) patients. Its pathology and relationship with other comorbidities remain unclear. This study was designed to determine the prevalence and predictors of proximal aortic dilatation after TOF repair. We retrospectively investigated all patients who underwent follow-up cardiac magnetic resonance imaging (CMR; at least 4 years after TOF repair) between March 2004 and December 2019. The dimensions at the ascending aorta (AAo) and sinus of Valsalva (SoV) levels were measured. Aortic dilatation was defined as an internal aortic diameter that was >2 standard deviation of the previously published normal values. We included 77 patients (mean age 28.9 ± 10.5 years, 41.5% female, mean follow-up of 24.5 ± 8.1 years). AAo and SoV were dilated in 19 (24.6%) and 43 (55.8%) patients, respectively. Patients with dilated AAo and SoV were older during the corrective surgery (p < 0.001 and p = 0.004, respectively) and during CMR (p = 0.002 and 0.024, respectively) than patients without AAo and SoV dilatation. Patients of the dilated AAo group were more likely to have prior palliative shunt (p = 0.008), longer shunt duration (p = 0.005), and a higher degree of aortic valve regurgitation (AR) fraction (p < 0.001) and to undergo pulmonary (PVR) and/or aortic valve replacement (p < 0.001 and p = 0.013, respectively). PVR (p = 0.048, odds ratio = 6.413, and 95% CI = 1.013-40.619) and higher AR fraction (p = 0.031, odds ratio = 1.194, and 95% CI = 1.017-1.403) were independent predictors for AAo dilatation. Aortopathy is a common progressive complication that may require reintervention and lifelong follow-up. Our study shows that proximal aortic dilatation may be attributed to factors that increase the volume overload across the proximal aorta, including late corrective surgery and palliative shunt. We also found that PVR and higher AR fraction are independent predictors of AAo dilatation.

[The adult with tetralogy of fallot: what the clinical cardiologist needs to know]

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. After more than seven decades of the first palliative surgery, TOF prognosis has changed dramatically. The prevalence of TOF is approximately 3 per 10 000 births, representing 7 to 10% of congenital heart disease. With a higher survival into adulthood, the clinical cardiologist faces challenges in the management of this population, from severe pulmonary regurgitation to heart failure and ventricular arrhythmias. Its prevalence is approximately 3 per 10 000 live births, representing 7 to 10% of congenital heart disease. This review will describe the most relevant aspects of the care of adult patients with this disease.