Risk factors associated with arterial switch operation for transposition of the great arteries

INTRODUCTION AND OBJECTIVES: The present study was undertaken to determine the risk factors for early mortality following an arterial switch operation. PATIENTS AND METHOD: From January 1994 through October 2003, 78 pediatric patients underwent surgical repair. Simple transposition was present in 48 patients (61.5%), 29 (37.2%) had an associated ventricular septal defect, and one had a Taussig-Bing anomaly. The risk factors analyzed were: the patient's age and weight at the time of the intervention, repair of a coexisting ventricular septal defect, coronary artery anatomical pattern, duration of cardiopulmonary bypass, duration of aortic cross-clamping, and duration of circulatory arrest. All factors were evaluated for strength of association with the duration of mechanical ventilation, the length of intensive care unit stay, and mortality. RESULTS: Overall, the early mortality rate was 9% (7/78). Some 14 patients (17.9%) underwent simultaneous repair of a ventricular septal defect. Patients with an intramural coronary artery (n=3, 3.8%) or a single coronary ostium (n=5, 6.4%) were the only ones who had a significant (P<.05) mortality risk, at 50% (4/8). Circulatory arrest was implemented in 53 (68%) patients. There were significant correlations between the duration of circulatory arrest and the ventilator support time (r=0.3, P<.05) and the duration of stay in the intensive care unit (r=0.3, P<.05). CONCLUSIONS. The risk of early death was increased when more complex coronary artery anatomical variants were present. As the period of circulatory arrest lengthened, the mechanical ventilation time and duration of intensive care unit stay increased.     

Exercise performance in children and adolescents after the Ross procedure

OBJECTIVES: The Ross procedure is increasingly utilized in the treatment of aortic valvar disease in children and adolescents. Our purpose was to compare pre- and post-operative exercise state in this population. METHODS: We included patients who underwent the Ross procedure at our institution between January, 1995, and December, 2003, and in whom we had performed pre- and post-operative exercise stress tests. We used a ramp bicycle protocol to measure consumption of oxygen and production of carbon dioxide. Cardiac output was estimated from effective pulmonary blood flow by the helium acetylene re-breathing technique. RESULTS: We studied 26 patients, having a median age at surgery of 15.7 years, with a range from 7.5 to 24.1 years. The primary indication for surgery in two-thirds was combined aortic stenosis and insufficiency. Median time from the operation to the post-operative exercise stress test was 17.4 months, with a range from 6.7 to 30.2 months. There was a trend toward lower maximal consumption of oxygen after the procedure, at 36.3 plus or minus 7.6 millilitres per kilogram per minute (83.9% predicted) as opposed to 38.6 plus or minus 8.4 millilitres per kilogram per minute (88.5% predicted, p equal to 0.06). Patients after the procedure, however, had significantly increased adiposity, so that there was no difference in maximal consumption of oxygen indexed to ideal body weight before and after the operation. In 20 of the patients, aerobic capacity improved or was stable after the operation. There was no post-operative chronotropic impairment. CONCLUSIONS: In the majority of patients following the Ross procedure, exercise performance is stable and within the normal range of a healthy age and sex matched population, despite sedentary lifestyles and increased adiposity.     

Aortic reservoir function after arterial switch operation in elementary school-aged children

BACKGROUND: After the arterial switch procedure, decreased distensibility of the aortic root has been reported, which means impaired aortic reservoir function of the coronary circulation, but there have been no reports regarding the relationship of this issue to myocardial perfusion. Therefore, in the present study the aortic reservoir function and coronary supply-demand balance were examined in patients after undergoing the arterial switch operation (ASO) around the time of entering elementary school. METHODS AND RESULTS: Diastolic runoff (DR), which is the percentage of diastolic blood flow to total cardiac output, was measured as the index of aortic reservoir function. The subendocardial viability ratio was investigated as the index of coronary supply - demand balance. In the patient group, the aortic root was dilated (p<0.0001) and distensibility was impaired (p<0.0001) in comparison with an age-matched control group. However, there was no difference between the 2 groups in DR or subendocardial viability ratio. CONCLUSIONS: Coronary supply - demand balance was preserved in the pediatric ASO patients, despite the aortic root dysfunction. The preserved DR suggests that dilatation of the aorta compensates for aortic reservoir function. Because large artery dysfunction predicts future cardiovascular diseases, careful follow-up is crucial.     

大动脉转位患者动脉调转术后死亡的危险因素分析

Objective To analyze the in-hospital mortality and factors affecting in-hospital mortality for patients with transposition of the great arteries (TGA) undergoing arterial switch operation (ASO).Methods Between January 2004 and December 2007, ASO was performed in 169 patients [129 male, 40 female; mean age (11.71± 26. 3) months] with TGA. The patients were divided in intact ventricular septum group( n = 56): TGA with intact ventricular septum and ventricular septal defect group (n = 113 ):TGA with ventricular septal defect. Multiple logistic regression analysis was performed to identify the risk factors of in-hospital mortality. Results The overall in-hospital mortality was 11.24% (19/169). The yearly in-hospital mortality was similar between intact ventricular septum group and ventricular septal defect group. With the improvement of perioperative treatment, the in-hospital mortality decreased from 16.67% in 2004 to 3.92% in 2007. The multivariate analysis revealed that body weight ≤3 kg( OR:4. 571, P =0. 0409), complicating ventricular septal defect( OR:4. 444,P =0. 0406), complex TGA( OR:4. 321 ,P =0. 0140), coronary anomalies( OR:4. 867,P =0. 0104) and non-type A coronary arteries( OR:3. 045,P =0. 0243) were independent predictors for poor early postoperative survival. Conclusion Body weight ≤3 kg,complicating ventricular septal defect, complex TGA, coronary anomalies are independent predictors for increased in-hospital mortality in patients with transposition of TGA and undergoing arterial switch operation.     

Ten-year experience with the arterial switch operation

BACKGROUND: Arterial level repair is considered the most appropriate procedure for transposition of the great arteries. This report describes our experience with the arterial switch operation over the past decade. METHODS AND RESULTS: From January 1991 to January 2001, a total of 299 patients underwent an arterial switch operation for transposition of the great arteries or double-outlet right ventricle. Group I (n=169, 56.5%) comprised patients with transposition of the great arteries in whom the ventricular septum was essentially intact. Group II patients (n=130, 43.5%) had transposition of the great arteries with an additional significant ventricular septal defect or had double-outlet right ventricle with a subpulmonic ventricular septal defect. Of the total, 245 (82%) were males and 54 (18%) were females. In group I, the ages ranged from 2 days to 18 years (median 19 days) and weight ranged from 1.7 to 68 kg (median 2.5 kg). In group II, the ages ranged from 4 days to 4 years (median 90 days) and weight ranged from 2.5 to 17 kg (median 4 kg). Fifteen percent of the patients (25/169) in group I and 30% of the patients (39/130) in group II had features of bacteriologic infection. Arterial switch operation was performed on standard lines. In group I, 141 patients (83.4%) had a primary arterial switch operation while 28 (16.6%) underwent a rapid two-stage repair. Twenty-three patients required concomitant relief of associated anatomic left ventricular outflow tract obstruction. Operative mortality was 8.8% (15/169) in group I and 33% (44/130) in group II with an overall mortality of 19% (59/299). The major causes of operative mortality included pulmonary arterial hypertensive crisis (n=21), sepsis and related complications (n=16), and left ventricular failure (n=8). Coexisting arch anomalies, longer cross-clamp time, late presentation, and preoperative bacteriologic infections were incremental risk factors. Follow-up ranged from 1 to 10 years and was 87% complete. On follow-up, 91% of the patients were asymptomatic and off all medications. There were 3 late deaths and 5 patients required reoperation. CONCLUSIONS: Excellent long-term results are obtained in operative survivors following the arterial switch operation. However. operative mortality remains a concern in our set-up.     

大动脉转位患者动脉调转术后死亡的危险因素分析

目的 分析接受动脉调转术(ASO)治疗大动脉转位(TGA)患者发生住院期间死亡的危险因素.方法2004年1月至2007年12月,入选169例实施ASO的TGA患者,其中男性129例,女性40例,年龄(11.71±26.3)个月.患者分为室间隔完整组(室间隔完整型TGA患者56例)和室间隔缺损组(室间隔缺损型TGA患者113例).对ASO术后发生住院期间死亡的危险因素进行多元logistic回归分析.结果ASO术后发生住院期间死亡19例(11.24%),住院期间病死率由2004年的16.67%下降到2007年的3.92%.2004至2007年,室间隔完整组与室间隔缺损组各年的住院期间病死率差异均无统计学意义.多元logistic回归分析显示,ASO治疗TGA后住院期间死亡的危险因素为:体重≤3 kg(OR:4.571,P=0.0409)、合并室间隔缺损(OR:4.444,P=0.0406)、复杂畸形TGA(OR:4.321,P=0.0140)、Planche分型为非正常型(OR:4.867,P=0.0104)、Leiden分型为非A型(OR:3.045,P=0.0243).结论体重≤3 kg、合并室间隔缺损、复杂畸形TGA、冠状动脉异常是ASO治疗TGA后发生住院期间死亡的危险因素.

Abstract：

Objective To analyze the in-hospital mortality and factors affecting in-hospital mortality for patients with transposition of the great arteries (TGA) undergoing arterial switch operation (ASO).Methods Between January 2004 and December 2007, ASO was performed in 169 patients [129 male, 40 female; mean age (11.71± 26. 3) months] with TGA. The patients were divided in intact ventricular septum group( n = 56): TGA with intact ventricular septum and ventricular septal defect group (n = 113 ):TGA with ventricular septal defect. Multiple logistic regression analysis was performed to identify the risk factors of in-hospital mortality. Results The overall in-hospital mortality was 11.24% (19/169). The yearly in-hospital mortality was similar between intact ventricular septum group and ventricular septal defect group. With the improvement of perioperative treatment, the in-hospital mortality decreased from 16.67% in 2004 to 3.92% in 2007. The multivariate analysis revealed that body weight ≤3 kg( OR:4. 571, P =0. 0409), complicating ventricular septal defect( OR:4. 444,P =0. 0406), complex TGA( OR:4. 321 ,P =0. 0140), coronary anomalies( OR:4. 867,P =0. 0104) and non-type A coronary arteries( OR:3. 045,P =0. 0243) were independent predictors for poor early postoperative survival. Conclusion Body weight ≤3 kg,complicating ventricular septal defect, complex TGA, coronary anomalies are independent predictors for increased in-hospital mortality in patients with transposition of TGA and undergoing arterial switch operation.     

大动脉转位患者动脉调转术后死亡的危险因素分析

Objective To analyze the in-hospital mortality and factors affecting in-hospital mortality for patients with transposition of the great arteries (TGA) undergoing arterial switch operation (ASO).Methods Between January 2004 and December 2007, ASO was performed in 169 patients [129 male, 40 female; mean age (11.71± 26. 3) months] with TGA. The patients were divided in intact ventricular septum group( n = 56): TGA with intact ventricular septum and ventricular septal defect group (n = 113 ):TGA with ventricular septal defect. Multiple logistic regression analysis was performed to identify the risk factors of in-hospital mortality. Results The overall in-hospital mortality was 11.24% (19/169). The yearly in-hospital mortality was similar between intact ventricular septum group and ventricular septal defect group. With the improvement of perioperative treatment, the in-hospital mortality decreased from 16.67% in 2004 to 3.92% in 2007. The multivariate analysis revealed that body weight ≤3 kg( OR:4. 571, P =0. 0409), complicating ventricular septal defect( OR:4. 444,P =0. 0406), complex TGA( OR:4. 321 ,P =0. 0140), coronary anomalies( OR:4. 867,P =0. 0104) and non-type A coronary arteries( OR:3. 045,P =0. 0243) were independent predictors for poor early postoperative survival. Conclusion Body weight ≤3 kg,complicating ventricular septal defect, complex TGA, coronary anomalies are independent predictors for increased in-hospital mortality in patients with transposition of TGA and undergoing arterial switch operation.     

Replacement of the aortic valve after the arterial switch operation

An 11-month-old infant had undergone a primary arterial switch operation, including the Lecompte maneuver, for correction of discordant ventriculo-arterial connections and closure of an accompanying ventricular septal defect. At discharge, there were no signs of aortic valvar incompetence. Regurgitation across the aortic valve was detected first at the age of 2 years, and then increased progressively, as documented by serial echocardiographic studies. There had been no history of bacterial endocarditis. At the age of 10 years, echocardiography revealed severe aortic valvar incompetence. At operation, the aortic valve had three leaflets, all of which were short, with very restricted movement. Absence of sufficient leaflet tissue precluded a durable valvar reconstruction, so the aortic valve was replaced with a 21 mm mechanical prosthesis. Histological examination of the removed leaflets revealed nodular swelling due to mucous changes of the matrix, as well as fibrous alteration and formation of scar tissue, including areas of fibroblastic and capillary proliferation. There were no signs of calcification or acute inflammatory changes. Improvement of left ventricular function was observed both early postoperatively and later on. Our observation shows that aortic valvar incompetence after an arterial switch operation can be caused by degenerative changes of the neo-aortic leaflets, which prevent plastic reconstruction of the valve, necessitating valvar replacement.     

Heart rate recovery is associated with obesity traits and related cardiometabolic risk factors in children and adolescents

Background and aimsIncreased vagal activity is associated with obesity and metabolic risk in children and adolescents. The aim of the present cross-sectional study was to examine the association of parasympathetic function, as assessed by heart rate recovery (HRR) from a maximal exercise cycle-ergometer test, with obesity traits and related cardiometabolic risk factors in Spanish children and adolescents.Methods and resultsA sample of 437 Spanish 9-year-old-children and 235 15-year-old-adolescents participated in the study. The variables measured were anthropometric characteristics (height, body mass and waist circumference) and physical activity using the Actigraph accelerometer. Additional measured outcomes included fasting insulin, triglycerides, high-density lipoprotein cholesterol (HDLc) and blood pressure. A metabolic risk score was computed as the mean of the standardised outcomes scores. The HRR was calculated as the difference between peak heart rate and heart rate 1, 3 and 5 min after cessation of the maximal ergometer test. Diastolic blood pressure was associated with all the HRR parameters in 9-year-old-girls. In 9-year-old-boys, the 3-min HRR was inversely associated with systolic blood pressure (p < 0.05) and Homeostasis Model Assessment (HOMA) (p < 0.05). Five minute HRR was inversely associated with waist circumference (p < 0.05), sum of five skinfolds (p < 0.01) and HOMA (p = 0.004). There were no significant associations in adolescents. In 9-year-old-girls, the adjusted 5-min HRR showed significant differences between quartile 2 and 4 of metabolic risk (p = 0.011). In all samples, the adjusted HRR (1-, 3- and 5-min HRR) did not show significant differences across quartiles.ConclusionHRR was inversely associated with obesity traits and related cardiometabolic risk factors mainly in healthy boys.     

Late coronary complications after arterial switch operation and their treatment

Objectives: To report the late coronary complications and their treatment after arterial switch operation (ASO). Background: Asymptomatic patients after ASO may have coronary ostial stenosis or obstruction. Methods: Since 1980, 279 patients were operated with ASO. At the time of preparing this article, selective follow‐up coronary angiograms were done on 81 patients. Results: Coronary stenosis was found in six patients. A 6‐year‐old patient with left coronary artery (LCA) ostial stenosis and a 9‐year‐old patient with conus branch occlusion had good collaterals without a need for further treatment. One patient with LCA obstruction, myocardial infarction, and left ventricular failure was operated with osteoplasty at age of 16 years. In three essentially asymptomatic patients, stenting of LCA ostium stenosis was done: in two of them with drug‐eluting stents at 9 and 10 years of age and in one with bare‐metal stent at 18 years of age. One of these patients was earlier treated with balloon dilatation at 5 years of age which caused intimal dissection. Conclusions: Asymptomatic patients with an uneventful course after ASO may have coronary obstruction. This necessitates follow‐up coronary evaluation in all patients. Stenting of the coronary arteries is an option for treatment. © 2010 Wiley‐Liss, Inc.     

Coronary arterial anatomy in regard to the arterial switch procedure

SummarySince the success of the arterial switch procedure is dependent on the successful translocation of the coronary arteries, a thorough understanding of the anatomic variations of the coronary arteries is essential. We reviewed the anatomy of the coronary arteries encountered in 140 consecutive cases undergoing the arterial switch procedure for complete transposition at the Heart Institute of Japan. The anatomic variations, described using the Shaher and Puddu classification, varied significantly, requiring alteration in the surgical technique.     

25 years after the first arterial switch procedure: mid-term results

BACKGROUND: 25 years after the first successful arterial switch operation (ASO) for complete transposition of the great arteries (TGA), it is possible to evaluate the mid-term results after this procedure. PATIENTS AND METHODS: From March 1986 through December 1993, 188 patients with TGA underwent ASO (primary in 181 patients and secondary after previous banding of the pulmonary artery in 7 patients). Of the 181 patients with primary ASO, 152 had simple TGA or TGA with a small ventricular septal defect, 90 patients had TGA with a large ventricular septal defect, and 10 had a Taussig-Bing complex. Unselected subgroups of the patients were specifically examined with respect to general health, cognitive and motor development, exercise tolerance and cardiological status. Follow-up time was over 5 years except for the cardiac catheterizations, which were performed one year after ASO. RESULTS: Early mortality was 6.4% in the total group and 5.5% in the 181 patients with primary ASO. 5 patients (2.7%) died late and 5 patients needed reoperation during the follow-up period. Cumulative survival for the whole group was 91% at 5 and 10 years after ASO. 96% of the patients were unlimited in their physical activity, and 99% received no medication. Intelligence was not different from a normal population, but motor and neurological impairment was more frequent (23% and 9%, respectively). The Bruce treadmill test was normal in 47 of 50 patients, but provoked signs of myocardial ischemia or salvos of ventricular tachycardia in 3. ECG and Holter ECG showed normal sinus rhythm in 94.5%, important ventricular ectopy in 2.8% and ischemic changes in 1.4%. Right heart catheterization in 67 patients revealed flattening of the pulmonary trunk and frequently mild or rarely moderate pulmonary artery branch stenosis. Left heart catheterization in 71 patients demonstrated significant enlargement of the aortic annulus and root as well as frequent mild aortic insufficiency. One child had unexpected coronary artery occlusion,and 2 showed a hypoplastic left anterior descending coronary artery. In all patients except one, left ventricular ejection fraction was normal, but 6 patients had regional wall motion abnormalities. CONCLUSION: These results and those of other groups are encouraging, but prospective studies over a much longer follow-up time are necessary before definite conclusions can be drawn.     

Myocardial perfusion,function and exercise tolerance after the arterial switch operation

Objectives. This study was conducted to determine the prevalence of myocardial perfusion abnormalities at rest and exercise and to assess exercise capacity in children after the arterial switch operation.Background. There have been sporadic reports of myocardial ischemia or sudden death in children after the arterial switch operation for transposition of the great arteries, possibly related to inadequate coronary perfusion due to kinking or stenosis of the translocated coronary arteries.Methods. Myocardial perfusion at rest and peak exercise was assessed using the scintigraphic agent technetium-99m methoxyisobutyl isonitrile (sestamibi). Exercise capacity was determined with a modified Brace protocol. Ambulatory etectrocardiographic (ECG) Holter monitoring was performed. Ventricular function, contractility and wall motion were assessed echocardiographically.Results. Twenty-three children (aged 4.2 to 7.9 years) underwent evaluation. Abnormalities were found on the rest perfusion scans in 22 children (95.6%). The left ventricular myocardium was divided into 13 segments for analysis. Of 299 rest segments, 225 (75.3%) were normal, 11 (3.7%) showed mild defects, 45 (15%) moderate defects and 18 (6%) severe defects at rest. At peak exercise, 237 segments (79.3%) were normal, 24 (8%) showed mild defects, 33 (11%) moderate defects and 5 (1.7%) severe defects. Compared with rest studies, myocardial perfusion grade at exercise was unchanged in 246 segments (82.3%), improved in 42 (14%) and worsened in 11 (3.7%). All patients had normal exercise tolerance without symptoms or ischemic ECG changes. No ventricular tachycardia was seen on Holter monitoring. All patients had a shortening fraction ≥27%. Left ventricular contractility was normal in 12 children in whom it was assessed. Regional wall motion was normal in 17 children with adequate echocardiographic images for this analysis.Conclusions. Myocardial perfusion scan abnormalities assessed by technetium-99m sestamibi are common after an arterial switch operation. These abnormalities are of uncertain clinical significance and generally lessen with exercise. The normal exercise tolerance without symptoms or ECG changes suggests that myocardial perfusion is adequate during the physiologic stress of exercise in children up to 8 years after an arterial switch operation.     

Myocardial viability assessed by positron emission tomography in infants and children after the arterial switch operation and suspected infarction

OBJECTIVES: The aim of the study was to assess regional glucose metabolism and contractile function by gated positron emission tomography using fluoro-18-deoxyglucose (FDG-PET) in pediatric patients after the arterial switch operation and suspected myocardial infarction. BACKGROUND: Morbidity and mortality after the arterial switch operation for transposition of the great arteries are often related to impaired coronary function. Justification of high-risk revascularization procedure in infancy requires thorough evaluation of myocardial viability. Although PET is state-of-the-art for evaluation of myocardial viability in adults there are no reports on its impact and feasibility in infants and children. METHODS: We applied electrocardiogram-triggered FDG-PET for assessment of metabolic and functional status of the myocardium in seven infants and seven children. Glucose metabolism, wall motion and wall thickening were evaluated visually and quantitatively on the basis of parametric 3-D images. Additionally, single-photon emission computed tomography perfusion scan was performed in six children. RESULTS: In two of seven infants, FDG-PET demonstrated viable myocardium in akinetic or hypokinetic regions corresponding to a coronary artery stenosis or occlusion. Therefore, indication for revascularization was derived from this finding. In six of the seven children, impaired glucose uptake reflecting myocardial scarring was present. Two patients had pathological findings on coronary angiography and signs of ischemia but were not suitable for revascularization. CONCLUSIONS: Myocardial viability and contractile function can be assessed simultaneously by gated FDG-PET even in infant hearts. This method contributes pertinent information to guide further therapy after the arterial switch operation and suspected myocardial infarction.     

Insulin resistance is associated with arterial stiffness independent of obesity in male adolescents.

To determine the relationship between insulin resistance (IR) and arterial stiffness independent of obesity in male adolescents, we evaluated body fat, lipid parameters, indices of IR (fasting insulin, and the homeostasis model assessment of insulin resistance [HOMA-IR]), indices of insulin sensitivity (IS) (fasting glucose/fasting insulin [GF/IF], and the quantitative insulin sensitivity check index [QUICKI]), and lifestyle parameters in 256 male adolescents. We divided the study group into the following four subgroups based on the median value of HOMA-IR and obesity: non-obese with IS, non-obese with IR, obese with IS, and obese with IR. In order to estimate arterial stiffness, we measured brachial ankle pulse wave velocity (baPWV). Despite having a high body mass index (BMI), obese-IS adolescents showed a significantly lower fasting insulin and baPWV, but had higher IS indices than non-obese-IR adolescents. After an adjustment for age, BMI, waist-to-hip ratio, mean blood pressure, heart rate, total cholesterol level, triglyceride, alanine aminotransferase (ALT) level, physical activity, and television and computer usage, multiple regression models showed that baPWV was independently correlated with IR and IS indices. In conclusion, our results demonstrate an association between IR and baPWV independent of weight, suggesting that IR is a risk factor for the development of early atherosclerosis. Interventions that decrease IR in addition to weight reduction may be necessary to alter the early development of cardiovascular risk.     

Risk factors for dislypidemia in obese children and adolescents

OBJECTIVE: To assess the risk of dislypidemia associated with obesity in children and adolescents. MATERIAL AND METHODS: A cross sectional study was conducted with 62 obese children (BMI > 95 centile and tricipital skinfold thickness > 90 centile) and 70 non-obese children (BMI 5-85 centile) ages 5-15 years, without chronic diseases. Subjects' characteristics and family background of chronic diseases were collected and a lipid profile was determined. The risk of lipid alterations in the obese children was calculated using odds ratio (OR) and multivariate analysis. RESULTS: Mean age was 9.8 +/- 2.7 years in both groups; 63 girls and 69 boys were included. Obesity was associated with abnormal values for cholesterol, triglycerides, LDL, HDL and dislypidemia (> 1 abnormal value) (OR 4.47-15.0). In obese children and adolescents the multivariate analysis showed that female gender was associated with dislypidemia. CONCLUSION: Obesity in children and adolescents is associated with high risk of dislypidemia; the risk is higher among females.