Sudden Death Due to Coronary Artery Lesions Long-term After the Arterial Switch Operation: A Systematic Review.

BACKGROUND: The arterial switch operation (ASO) is the preferred procedure for children with dextrotransposition of the great arteries or Taussig-Bing anomaly. Short- as well as long-term outcome of ASO are excellent, but coronary artery stenoses are reported as a common long-term complication. It has been hypothesized that these might result in sudden cardiac death late after ASO. METHODS: A systematic search of PubMed and EMBASE was conducted to evaluate sudden cardiac death because of coronary complications late after ASO. Data on patients surviving ≥ 5 years post-ASO were collected from selected studies, corrected for duplicate data, and analyzed. RESULTS: After duplicate data correction 52 studies remained for data analysis. Among the 8798 survivors with follow-up, 27 patients died ≥ 5 years post-ASO (0.3%). Of these patients, 10 were known with relevant residual lesions. Five late deaths were sudden, possibly from a cardiac cause. None of the late sudden deaths were confirmed to be coronary-related. CONCLUSIONS: Sudden cardiac death in asymptomatic patients as a result of coronary artery stenosis or occlusion is extremely rare, with 5 possible cases and no proven cases of coronary artery-related sudden cardiac death in 8798 patients with 66,450 patient follow-up years. Therefore, routine coronary imaging of asymptomatic, single-stage ASO patients is not justified.

Main pulmonary artery area limits exercise capacity in patients long-term after arterial switch operation.

OBJECTIVES: Despite excellent survival in patients after the arterial switch operation, reintervention is frequently required and exercise capacity is decreased in a substantial number of patients. This study relates right-sided imaging features in patients long-term after the arterial switch operation to exercise capacity and ventilatory efficiency to investigate which lesions are functionally important. METHODS: Patients operated in the UMC Utrecht, the Netherlands (1976-2001) and healthy controls underwent cardiac magnetic resonance imaging and cardiopulmonary exercise testing within 1 week. We measured main, left, and right pulmonary artery cross-sectional areas, pulmonary blood flow distribution, peak oxygen uptake, and minute ventilation relative to carbon dioxide elimination. RESULTS: A total of 71 patients (median age, 20 [12-35] years, 73% were male) and 21 healthy controls (median age, 26 [21-35] years, 48% were male) were included. Main, left, and right pulmonary artery areas were decreased compared with controls (190 vs 269 mm(2)/m(2), 59 vs 157 mm(2)/m(2), 98 vs 139 mm(2)/m(2), respectively, all P < .001); however, pulmonary blood flow distribution was comparable (P = .722). Peak oxygen uptake and minute ventilation relative to carbon dioxide elimination were 88% ± 20% and 23.7 ± 3.8, respectively, with 42% and 1% of patients demonstrating abnormal results (≤ 84% and ≥ 34, respectively). The main pulmonary artery area significantly correlated with peak oxygen uptake (r = 0.401, P = .001) and pulmonary blood flow distribution with minute ventilation relative to carbon dioxide elimination (r = -0.329, P = .008). Subanalysis (<18, 18-25, >25 years) showed that the main pulmonary artery area was smaller in older age groups. In multivariable analysis, the main pulmonary artery area was independently associated with peak oxygen uptake (P = .032). CONCLUSIONS: In adult patients after the arterial switch operation, narrowing of the main pulmonary artery is a common finding and is the main determinant of limitation in functional capacity, rather than pulmonary branch stenosis.