Author + information
- Published online April 12, 2017.
- Beatrice Bonello, MD,
- Darryl F. Shore, MB ChB,
- Anselm Uebing, MD,
- Gerhard-Paul Diller, MD, PhD,
- Jennifer Keegan, PhD,
- Elisabeth D. Burman, MSc,
- Yumi Shiina, MD,
- Lorna Swan, MD,
- Dudley J. Pennell, MD,
- Philip J. Kilner, MD, PhD,
- Sylvain Beurtheret, MD,
- Michael A. Gatzoulis, MD, PhD and
- Sonya V. Babu-Narayan, MBBS, BSc, PhD∗ ( )()
- ↵∗National Institute for Health Research Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, United Kingdom
Although the high prevalence of aortic root dilatation in adults with repaired tetralogy of Fallot (rTOF) is well established (1,2), evidence to guide clinical follow-up and decision making remains sparse.
We sought to define the features, determinants, and rate of progression of aortic dilatation in adults with rTOF using cardiovascular magnetic resonance (CMR).
We retrospectively identified adults with rTOF who had 2 interval CMR scans. Aortic dimensions were measured at sinus, sinotubular junction (STJ), and mid-ascending aortic level at both time points blinded to scan order and other clinical data. Dilatation was defined as diameter >2 SD larger than our published normal CMR aortic dimensions adjusted for age (3).
We retrospectively studied 110 patients (57 male; median age 30.9 years [interquartile range (IQR): 22.9 to 39.4 years]). One patient with aortic valve endocarditis requiring aortic valve surgery was excluded. Forty had a shunt prior to repair (median age at repair 4.5 years [IQR: 2.1 to 9.2 years]); 14 were repaired before 1 year of age; 9 had pulmonary atresia; 24 had right-sided aortic arch; and 11 were successfully treated for systemic hypertension. Twenty-nine patients (27%) had mild and 6 (5%) had moderate aortic regurgitation.
Seventy-six patients (69%) had aortic dilatation. Dilatation was present in 30 patients (27%) at sinus level, in 73 (66%) at STJ level, and in 24 (21%) at ascending aortic level. Thirty- five patients (31%) had normal aortic dimensions (Figure 1A). Patients repaired before 1 year of age were less likely to have aortic dilatation at any level compared with the remaining patients (p = 0.001).
Male sex and history of palliative shunt were independent predictors of aortic dilatation at any level (p < 0.0001 and p = 0.023, respectively) and were independent predictors of STJ dilatation (p = 0.0001 and p = 0.033, respectively). Male sex and pulmonary atresia were independent predictors of aortic sinus dilatation (p = 0.008 and p = 0.0009, respectively). Male sex, later repair, and pulmonary atresia were independent predictors of ascending aortic dilatation (p = 0.008, p = 0.006, and p = 0.0004, respectively).
During a median interval of 6.3 (IQR: 5.1 to 7.6) years, aortic diameters increased in 47% patients (25% at sinus, 21% at STJ, and 35% at ascending aortic level) at rates between approximately 0.2 to 0.4 mm/year (Figure 1B). Even among patients with sinus diameter ≥45 mm at baseline (n = 5), there was no increase.
Predictors of aortic diameter increase at STJ level were older age, later repair, and right aortic arch. No predictors of aortic diameter increase at other levels were ascertained.
There were no aorta-related events during follow-up. Aortic regurgitation progressed from mild to moderate in only 2 patients without progressive aortic dilatation.
In conclusion, our data show that aortic dilatation is common, most frequently at STJ level (97% of patients with dilated aorta). Aortic dimensions increased in approximately 50% of patients during a 6-year follow-up, most commonly in the ascending aorta, but with reassuringly low rates of progression.
Previous studies have reported aortic root dilatation in rTOF (1,2). We also found associated ascending aortic dilatation in 21% of the patients. Risk factors for aortic dilatation were similar to those previously reported (1,2) and are those that lead to increased volume overload of the aorta prior to repair. The combination of these with the intrinsically abnormal aortic vessel wall (4) may contribute to aortic dilatation. With earlier surgical repair, the importance of aortic dilatation may decrease.
We demonstrated a very low rate of aortic diameter progression comparable with known age-related increase in normal volunteers. Recent consensus recommendations suggest replacement of the ascending aorta when its diameter is at least 55 mm (5). Our data would not support a more aggressive approach or very frequent aortic assessment with CMR.
Please note: This project was supported by the National Institute for Health Research Cardiovascular Biomedical Research Unit of Royal Brompton and Harefield National Health Service Foundation Trust and Imperial College London. Dr. Bonello has received support from the French Federation of Cardiology. Dr. Pennell has received a research grant from Siemens; consults for ApoPharma; and owns stock in and is a director of CVIS. Dr. Babu-Narayan has received support from the British Heart Foundation (FS/11/38/28864). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Bonello and Shore are joint first authors. This report is independent research by the National Institute for Health Research Biomedical Research Unit Funding Scheme. The views expressed in this publication are those of the author(s) and not necessarily those of the National Health Service, the National Institute for Health Research, or the Department of Health.
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