Young adults after arterial switch operation for transposition of the great arteries in Switzerland: a growing population

Young adults after arterial switch operation for transposition of the great arteries in Switzerland: a growing population.

Ruperti-Repilado FJ, Affolter J, Bouchardy J, Gabriel H, Stämpfli SF, Engel R, Schwerzmann M, Greutmann M, Tobler D.Swiss Med Wkly. 2022 Feb 23;152:w30114. doi: 10.4414/smw.2022.w30114. eCollection 2022 Feb 14.PMID: 35230031

 

Take Home Points:

1. Patients with d- transposition of the great arteries (d-TGA) post arterial switch generally have a good biventricular function and a normal exercise capacity.
2. Some of these patients suffer from cardiac events or require reinterventions, and they are likely patients with complex d-TGA.
3. Pregnancy within this cohort is largely safe with favourable outcomes.

Commentary from Dr. MC Leong (Kuala Lumpur), section editor of ACHD Journal Watch:

Previous studies have reported the long-term outcomes of patients with d-transposition of the great arteries (d-TGA) after the arterial switch operations (1-4). These studies, which were retrospective in nature, were usually flawed with issues inherent in retrospective studies, e.g., missing data, patients lost to follow up and recall errors. In this study, the authors attempted to overcome these deficiencies by examining data prospectively. Data were extracted from a prospectively collected Swiss Adult Congenital HEart disease Registry (SACHER). The registry was established in 2013 and was webbed-based (5). In this study, the authors examined the outcomes of patients with d-TGA post arterial switch operation in the hope of raising awareness among general practitioners and general cardiologists regarding this growing population and their potential complications.

 

All 149 patients with d-TGA post arterial switch in the registry were included. Baseline characteristics of the cohort were tabulated in Table 2. In the study, the authors echoed the findings of previous studies, which demonstrated that adults post arterial switch operation generally presented with good biventricular function and normal exercise capacity. However, many had residual lesions, which may or may not require intervention. The usual residua of RVOT obstruction, branch pulmonary artery stenoses, infective endocarditis and etc., were largely similarly to those seen in previous reports. The study also touched on the functional status (VO2max and NT-proBNP) as well as pregnancy outcomes which were largely unremarkable.

 

Interestingly. the authors showed that patients with complex d-TGA tended to suffer from cardiac events (occurring in 18% of patients with complex d-TGA) and required reintervention (Figure 1). These patients also had a trend towards a lower survival compared to their peers with simple TGA but the difference was not statically significant. The authors argued that this might be due to the overall low number of outcomes. Of the outcome examined by the study, one that particularly interested me was the growth of neo-aortic root and the accompanying neo-aortic valve incompetency. Admittedly, the reported aortic dissection in this population is exceedingly low. However, the study showed that the majority of the patients had at least moderate dilatation of the aortic root, and they demonstrated a marginal but progressive growth in the aortic dimensions over time (Table 2 & S2). Whether many of these patients would eventually require intervention in the distant future is yet to be seen. Only time will tell. Equally interesting was the presence of the increase in the QRS duration over time (Table S2). Its significance is yet to be determined, but one would assume that a progressive increase in the QRS duration may lead to inter-ventricular dyssynchrony, which may cause deterioration of heart function in the long run.

 

All in all, this is an interesting audit of the Swiss d-TGA cohort. The authors should be commended for establishing the prospectively collected SACHER registry. It would give systematically collected outcome data regarding this cohort of patients in the distant future and help understand this unique cohort. We would wait with much eagerness for the long-term effects of neo-aortic root dilatation as well as the prolonged QRS as they unfold over time.

Reference:

1. Tobler D, Williams WG, Jegatheeswaran A, Van Arsdell GS, McCrindle BW, Greutmann M, Oechslin EN, Silversides CK. Cardiac outcomes in young adult survivors of the arterial switch operation for transposition of the great arteries. J Am Coll Cardiol. 2010 Jun 29;56(1):58-64.
2. Khairy P, Clair M, Fernandes SM, Blume ED, Powell AJ, Newburger JW, Landzberg MJ, Mayer JE Jr. Cardiovascular outcomes after the arterial switch operation for D-transposition of the great arteries. Circulation. 2013 Jan 22;127(3):331-9.
3. Santens B, Van De Bruaene A, De Meester P, Gewillig M, Troost E, Claus P, Bogaert J, Budts W. Outcome of arterial switch operation for transposition of the great arteries. A 35-year follow-up study. Int J Cardiol. 2020 Oct 1;316:94-100.
4. Kempny A, Wustmann K, Borgia F, Dimopoulos K, Uebing A, Li W, Chen SS, Piorkowski A, Radley-Smith R, Yacoub MH, Gatzoulis MA, Shore DF, Swan L, Diller GP. Outcome in adult patients after arterial switch operation for transposition of the great arteries. Int J Cardiol. 2013 Sep 10;167(6):2588-93.
5. Tobler D, Schwerzmann M, Bouchardy J, Engel R, Stambach D, Attenhofer Jost C, et al.; On Behalf Of Sacher. Swiss Adult Congenital HEart disease Registry (SACHER) – rationale, design and first results. Swiss Med Wkly. 2017 Oct;147:w14519