Coronary Revascularization of Giant Aneurysms in Children With Kawasaki Disease: A Report of Two Cases.

In recent years, >100 cases of coronary artery stenotic lesions due to Kawasaki disease were treated with coronary artery bypass grafting (CABG). Surgical indications include stenosis of >75%, myocardial infarction history, electrocardiographic changes, and ischemia, as detected by myocardial scintigraphy and electrocardiography, due to drugs or exercise. Some centers have reported good patency rates, even in infants. The advantages of CABG in younger patients are minimal loss of left ventricular function, early elimination of post-operative ischemia risk, and improved quality of life. However, the disadvantage of performing CABG in younger patients is the small coronary artery diameter and the thin vessel wall, which can lead to post-operative occlusion, especially when performed by inexperienced surgeons. The optimal timing of CABG varies by institution and case, which depends on the presence or absence of complications, such as left ventricular dysfunction or valve regurgitation, and surgeon's experience. Importantly, unlike adult surgery, childhood CABG needs to be kept open for the very longest possible period of time to determine the optimal conditions for surgery. We report two pediatric cases of giant coronary artery aneurysms diagnosed in infancy. During school age, the patients had a mild decline of left ventricular ejection function. In one case, there were no clinical symptoms because of the development of collateral vessels and limitation of exercise. Both patients underwent surgery with good results. The gastric gastroepiploic artery could be anastomosed owing to the development of collateral blood vessels, although it was obstructed. At 1 year after surgery, both patients had a good post-operative course without complications of anastomotic stenosis or myocardial damage due to aneurysm resection. If conditions are favorable, bypass surgery can be postponed to several years until the coronary arteries are sufficiently large to warrant a delay in coronary artery stenosis in cases of infantile Kawasaki disease.

Exercise echocardiography demonstrates potential myocardial damage in patients with repaired tetralogy of Fallot using layer-specific strain analysis.

INTRODUCTION: Exercise stress echocardiography and layer-specific strains are emerging as important tools for cardiac assessment. This study was aimed to evaluate layer-specific strains and torsion parameters during exercise in order to investigate the characteristics of cardiac dysfunction in patients with repaired tetralogy of Fallot and to detect subclinical left ventricular dysfunction. MATERIALS AND METHODS: Thirteen patients with repaired tetralogy of Fallot (median age, 17.3 [interquartile range, 14.5-22.9] years; 6 males) and 13 controls (median age, 28.5 [interquartile range, 27.6-31.6] years; 13 males) underwent echocardiography at rest and during supine exercise. Layer-specific longitudinal strain and circumferential strain of three myocardial layers (endocardium, midmyocardium, and epicardium), torsion, and untwisting rate were measured using two-dimensional speckle-tracking echocardiography. RESULTS: Peak endocardial papillary circumferential strain (-21.1 ± 2.6% vs. -25.8 ± 3.8%, p = 0.007), midmyocardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.001), epicardial apical circumferential strain (-11.1 ± 4.0% vs. -15.6 ± 3.2%, p = 0.021), and torsion (8.9 ± 6.0 vs. 14.9 ± 4.8 degree, p = 0.021) were significantly lower in the repaired tetralogy of Fallot group than in the control group during exercise, though no significant difference was found between patients and controls at rest. CONCLUSIONS: Analysis of layer-specific strains and torsion parameters during exercise could detect subclinical left ventricular dysfunction in patients with repaired tetralogy of Fallot, which might reflect potential myocardial damage, at a stage where these parameters have normal values at rest. This finding provides new insight into the mechanisms of cardiac dysfunction in patients with repaired tetralogy of Fallot.

New insight into the intraventricular pressure gradient as a sensitive indicator of diastolic cardiac dysfunction in patients with childhood cancer after anthracycline therapy.

Cardiac dysfunction due to cardiotoxicity from anthracycline chemotherapy is a leading cause of morbidity and mortality in survivors of childhood cancer. The intraventricular pressure gradient (IVPG) of the left ventricle (LV) is the suction force of blood from the left atrium to the LV apex during early diastole and is a sensitive indicator of diastolic function. We assessed IVPG as a new indicator of the cardiac dysfunction in survivors of childhood cancer after anthracycline therapy. We performed a prospective echocardiographic study on 40 survivors of childhood cancer aged 6-26 years who received anthracycline therapy (group A) and 53 similar-age normal controls (group N). The subjects were divided into the younger groups, N1 and A1 (age < 16 years); older groups, N2 and A2 (age ≥ 16 years). IVPG was calculated using color M-mode Doppler imaging of the mitral inflow using Euler's equation. Total IVPG was divided into the basal and mid-to-apical IVPG to demonstrate more clearly the mechanisms of the LV diastolic suction force. The total anthracycline dose was 16.2-600.0 mg/m2 (median 143.5 mg/m2). Total IVPG significantly decreased in group A2 compared with that in group N2 (0.39 ± 0.07 vs. 0.29 ± 0.11 mmHg/cm; p = 0.010). The mid-to-apical IVPG significantly decreased in groups A1 and A2 compared with that in groups N1 and N2, respectively (N1 vs. A1: 0.20 ± 0.05 vs. 0.16 ± 0.05 mmHg/cm, p = 0.036; N2 vs. A2: 0.21 ± 0.06 vs. 0.14 ± 0.06 mmHg/cm, p = 0.001). Basal IVPG, E wave, and E/e' were not significantly different between patients and normal controls. The total and mid-to-apical IVPG, especially mid-to-apical IVPG, could be sensitive new indicators in survivors of childhood cancer after anthracycline therapy.

In-Depth Insight Into the Mechanisms of Cardiac Dysfunction in Patients With Childhood Cancer After Anthracycline Treatment Using Layer-Specific Strain Analysis.

BACKGROUND: Anthracycline cardiotoxicity affects clinical outcomes, and its early detection using methods that rely on conventional echocardiography, such as left ventricular ejection fraction (LVEF) is difficult. This study aimed to evaluate the characteristics and the differences in cardiac dysfunction among childhood cancer survivors in 3 age groups using layer-specific strain analysis in a wide age range.Methods and Results:The 56 patients (median age: 15 [range: 6.8-40.2] years) who had been treated with anthracycline for childhood cancer were divided into 3 age groups (C1: 6-12 years, C2: 13-19 years, C3: 20-40 years) after anthracycline treatment, and 72 controls of similar ages were divided into 3 corresponding groups (N1, N2, and N3). Layer-specific longitudinal strain (LS) and circumferential strain (CS) of 3 myocardial layers (endocardium, midmyocardium, and epicardium) were determined using echocardiography. Myocardial damage had not occurred yet in C1. Endocardial CS at the basal level was less in C2 than in N2. Endocardial CS at all levels and midmyocardial CS at the basal and papillary levels were lower in C3 than in N3. LVEF and LS were not significantly different between patients and controls. CONCLUSIONS: Among survivors of childhood cancer, impaired myocardial deformation starts in adolescence and extends from the endocardium towards the epicardium and from the base towards the apex with age. These findings are a novel insight into the time course of anthracycline cardiotoxicity.

Assessment of early diastolic intraventricular pressure gradient in the left ventricle among patients with repaired tetralogy of Fallot.

Assessment of left ventricular (LV) dysfunction is vital in patients with repaired tetralogy of Fallot (rTOF). The early diastolic intraventricular pressure gradient (IVPG) in the LV plays an important role in diastolic function. IVPG is calculated as the intraventricular pressure difference divided by the LV length, which allows to account for differences in LV size and therefore calculate IVPG in children. We aimed to investigate the mechanisms of LV diastolic dysfunction by measuring mid-to-apical IVPG as an indicator of the active suction force sucking blood from the left atrium into the LV. We included 38 rTOF patients and 101 healthy controls. The study population was stratified based on age group into children (4-9 years), adolescents (10-15 years), and adults (16-40 years). IVPGs were calculated based on mitral inflow measurements obtained using color M-mode Doppler echocardiography. Although total IVPGs did not differ between rTOF patients and controls, mid-to-apical IVPGs in adolescents and adults were smaller among rTOF patients than among controls (0.15 ± 0.05 vs. 0.21 ± 0.06 mmHg/cm, p < 0.05; 0.09 ± 0.07 vs. 0.17 ± 0.05 mmHg/cm, p < 0.001; respectively). Additionally, only mid-to-apical IVPG correlated linearly with peak circumferential strain (ρ = 0.217, p = 0.011), longitudinal strain (ρ = -0.231, p = 0.006), torsion (ρ = -0.200, p = 0.018), and untwisting rate in early diastole (ρ = -0.233, p = 0.006). In rTOF, the mechanisms underlying diastolic dysfunction involve reduced active suction force, which correlates with reduced LV deformation in all directions.

Mechanisms of Left Ventricular Dysfunction Assessed by Layer-Specific Strain Analysis in Patients With Repaired Tetralogy of Fallot.

BACKGROUND: Left ventricular (LV) dysfunction in patients with repaired tetralogy of Fallot (rTOF) is an important risk factor for adverse outcomes. The aim of this study was to assess the details and time course of such LV dysfunction using layer-specific strain analysis by echocardiography.Methods and Results:The 66 patients with rTOF (mean age, 16.3±9.3 years) were divided into 3 groups (T1: 4-10 years, T2: 11-20 years, T3: 21-43 years), and 113 controls of similar age (mean age, 17.2±9.3 years) were divided into 3 corresponding groups (C1, C2, and C3). Layer-specific longitudinal strain (LS) and circumferential strain (CS) of 3 myocardial layers (endocardial, midmyocardial, and epicardial) were determined by echocardiography. Basal and papillary endocardial CS values were decreased in T1 compared with C1. With the exception of papillary epicardial CS, basal/papillary CS and LS of all 3 layers decreased in T2 compared with C2. Excepting papillary epicardial CS, all other values were decreased in T3 compared with C3. CONCLUSIONS: Potential myocardial damage was found in the endocardium at the basal and papillary levels of the LV in young patients with rTOF, extending from the endocardium to the epicardium and from the base to the apex. This is the possible time course of LV dysfunction in patients with rTOF.

Thrombolytic therapy in Kawasaki disease: a report of four cases.

Four patients with a thrombus in a coronary artery aneurysm due to Kawasaki disease (KD) were treated at our hospital between 1994 and 2009. All the cases were treated with intravenous coronary thrombolysis (IVCT) therapy and the cases with acute myocardial infarction were treated with additional intracoronary thrombolysis therapy. Although both thrombolytic therapies were effective, IVCT required more time than intracoronary thrombolysis to resolve the thrombus. We concluded that IVCT can be used as the first-line thrombolytic therapy for KD, except in cases with acute myocardial infarction.

National Japanese survey of thrombolytic therapy selection for coronary aneurysm: intracoronary thrombolysis or intravenous coronary thrombolysis in patients with Kawasaki disease.

BACKGROUND: Thrombolytic therapy for coronary aneurysm thrombosis of Kawasaki disease (KD) includes antiplatelet and anticoagulants, i.v. coronary thrombolysis (IVCT), and i.c. thrombolysis (ICT). Therapeutic methods, drugs and doses vary among medical facilities. METHODS AND RESULTS: A nationwide survey of thrombolytic therapy was conducted under the auspices of the Ministry of Health, Labour and Welfare Research Program to Intractable Diseases Research Grants. A secondary survey targeted 14 facilities conducting thrombolytic therapy during a 5 year period (2004-2009). The primary survey investigated performance of thrombolytic therapy for 23 KD patients at 14 facilities, and of these, five with acute myocardial infarction had received ICT and combined therapy. The secondary survey investigated the pre-treatment condition of aneurysm and thrombosis and actual treatment methods. ICT was effective for small thrombi (≤ 10 mm), while IVCT was effective even for giant thrombi (>10 mm). ICT was also effective for thrombi within several hours after formation. CONCLUSION: In the present nationwide survey, thrombolytic therapy was more effective in cases of a shorter duration between thrombus formation and the start of treatment. It was found that many facilities used only IVCT for thrombus alone. Medications given to KD children did not cause serious hemorrhagic complications, unlike in adults. Although doses exceeded recommended levels in many cases, the only complications were nasal bleeding and fever.

Analysis of arterial function in adults with a history of Kawasaki disease.

BACKGROUND AND PURPOSE: It remains controversial whether Kawasaki disease (KD) is a risk factor for the early onset of atherosclerosis. The purpose of the present study was to assess endothelial function and arterial stiffness as markers of the early onset of atherosclerosis in adult patients with a history of KD. METHODS AND SUBJECTS: We compared 14 adult patients with a history of KD with 41 healthy controls. To assess arterial endothelial function, we measured the reactive hyperemia-peripheral arterial tonometry (RH-PAT) index and augmentation index adjusted to 75 bpm (AIx@75) using the Endo-PAT 2000 (Itamar Medical, Caesarea, Israel). In addition, we analyzed medical history, blood pressure, lifestyle habits, and atherosclerosis-related serum biochemical markers [asymmetric dimethylarginine, adiponectin, lipoprotein (a), cholesterols, atherogenic index of plasma]. RESULTS: There was no difference between the KD and control groups with regard to the RH-PAT index values (2.10 ± 0.43 and 1.84 ± 0.49, respectively; p=0.19). However, in the KD group, the RH-PAT index values were negatively correlated with the febrile period in the acute phase of disease (r(2)=0.458, p=0.048). In addition, the AIx@75 values were higher in KD patients compared to healthy controls (-7.69 ± 11.86% and -15.87 ± 8.72%, respectively; p=0.01). No significant differences existed between the KD and control groups with regard to the serum biomarkers of atherosclerosis. CONCLUSIONS: We speculate that endothelial dysfunction in former KD patients is affected by the febrile period of the acute phase, and antiplatelet drugs may improve endothelial function. The increased arterial stiffness of patients caused by post-inflammatory fibrotic changes in the arterial wall indicates that adults with a history of KD have an increased risk of developing atherosclerosis.

Improvement in non-tachycardia-induced cardiac failure after radiofrequency catheter ablation in a child with a right-sided accessory pathway.

A 6-year-old boy was referred for an evaluation of intolerance to physical activity at his elementary school. The patient had no episodes of palpitations. He was diagnosed as Wolff-Parkinson-White syndrome with a right-sided accessory pathway (AP) and dilated cardiomyopathy (DCM). Ventricular dyskinesis was detected mostly in the ventricular septum. Because the asynchronous septal motion caused by pre-excitation through a right-sided AP might deteriorate his cardiac function, he underwent an AP ablation, after which the asynchronous ventricular wall motion disappeared and the wall thickness improved. We suggest that an AP ablation may be the treatment of first priority in patients who have DCM-like dyskinesis even without sustained tachyarrhythmias.

Histopathological characteristics of myocarditis in acute-phase Kawasaki disease.

AIMS: To elucidate the histopathological characteristics of myocarditis in acute-phase Kawasaki disease (KD). METHODS AND RESULTS: The examined materials were from 29 autopsied KD patients who died within 40 disease days following onset. Each heart was divided into three levels: base, middle and apex. At each of these levels, the myocardium was divided further into the epicardial, middle and endocardial layers, and the time-courses of the changes in the myocarditis and the distribution of inflammation were analysed. Inflammatory cell infiltration, consisting mainly of lobulated leucocytes and large mononuclear cells, was seen in the myocardial interstitium in all cases. Inflammatory cell infiltration was already seen by disease day 6 in a patient with no coronary arteritis; it became prominent after day 10 and gradually disappeared after day 20. Myocarditis was initially distributed diffusely throughout the heart, but after day 10 it was localized in the base and epicardial layer. CONCLUSIONS: In KD, myocarditis develops even earlier than epicardial coronary arteritis; it peaks by disease day 10 and then disappears gradually after day 20. The myocarditis is distributed unevenly, ranging from the entire heart to the epicardial layer of the base of the heart.

Non-invasive assessment of liver fibrosis in patients after the Fontan operation.

BACKGROUND: This study analyzed the change in liver fibrosis markers after the Fontan operation and investigated their clinical usefulness as an index of congestive liver fibrosis. METHODS: The study enrolled 24 patients who underwent the Fontan operation between January 1994 and December 2008. We subdivided the postoperative period into four intervals and then compared the hepatological markers during each. Eighteen patients underwent postoperative cardiac catheterization and the correlation between hepatological markers and the inferior vena cava (IVC) pressure was analyzed. RESULTS: The mean age of the patients was 138.6 months and the mean interval between the Fontan operation and the examination was 97.8 months. Type IV collagen was extremely high in every interval (I, 286 ± 93; II, 265 ± 93; III, 305 ± 143; IV, 206 ± 70), while none of the laboratory variables changed significantly in each interval. A significant positive correlation was observed between type IV collagen and the IVC pressure, but no significant correlation with any other hepatological marker was detected. CONCLUSIONS: No specific parameter that reflects the progress in liver fibrosis was identified in this study. The possibility exists that type IV collagen reflects the degree of hepatic congestion.

Left ventricular torsion and strain in patients with repaired tetralogy of Fallot assessed by speckle tracking imaging.

BACKGROUND: In patients with tetralogy of Fallot (TOF), left ventricular (LV) dysfunction is an important factor associated with poor clinical outcome. OBJECTIVE: The purpose of this study was to investigate the torsion and multidirectional strain of the LV in patients with TOF. METHODS: Echocardiographic images were prospectively acquired in 29 patients who underwent TOF repair (age range, 5-25 years) and in 29 normal controls. Torsion and circumferential and longitudinal strain of the LV were assessed using speckle tracking imaging. RESULTS: The torsion in patients was smaller compared to that in the controls due to small apical rotation and/or inverse basal rotation (P < 0.01). Torsion and untwisting rates decreased with increasing age (R = 0.37, P < 0.05). Basal circumferential strain and strain rate (SR) at systole and diastole decreased with age (R = 0.58; R = 0.57; R = 0.57, all P < 0.001) and were smaller in patients compared to those in the controls (all P < 0.01). Septal longitudinal strain and SR at systole and diastole decreased with age (R = 0.52; R = 0.62; R = 0.71, all P < 0.001) and were smaller than those of the controls (P < 0.01), although lateral longitudinal strain and SR were relatively maintained. CONCLUSION: Abnormal torsion and strain pattern of the LV were observed in patients without symptoms of cardiac failure. Assessment of torsion and strain is a very sensitive tool to detect the early deterioration of LV function in patients with TOF.

Imbalance of peroxisome proliferator-activated receptor gamma and adiponectin predisposes Kawasaki disease patients to developing atherosclerosis.

BACKGROUND: It remains controversial whether Kawasaki disease (KD) is a risk factor for the onset of atherosclerosis. An imbalance of peroxisome proliferator-activated receptor γ (PPARγ) and adiponectin appears to play a role in the onset of atherosclerosis in adults, and we therefore examined PPARγ mRNA expression and adiponectin profiles in the peripheral white blood cells obtained from KD patients. METHODS: A total of 50 subjects were studied: nine patients with acute KD, 20 patients with convalescent KD, and 21 age-matched controls. The gene expression of PPARγ, monocyte chemoattractant protein-1, and CC chemokine receptor 2 present in the blood were quantified. The relative gene expression, adiponectin levels, and the three adiponectin isoforms were compared among the subjects. RESULTS: The abundance of PPARγ and CC chemokine receptor 2 mRNA was significantly increased in convalescent KD patients. The monocyte chemoattractant protein-1 level was also increased in convalescent KD patients. The level of high-molecular-weight adiponectin was significantly lower in convalescent patients compared to controls. The PPARγ transcription levels negatively correlated with apolipoprotein A-I levels in acute KD patients. CONCLUSIONS: The transcript abundance of PPARγ and low levels of high-molecular-weight adiponectin in KD patients may have important clinical implications on the development of premature atherosclerosis. Because the potential risk for developing atherosclerosis has not yet been verified, long-term observation is important, even in convalescent KD patients without coronary artery lesions.

Drug-eluting stents ameliorate pulmonary vein stenotic changes in pigs in vivo.

The outcome of stent implantation for pulmonary vein stenosis (PVS) in children remains poor. Several reports describe placing drug-eluting stents to treat PVS, but their effectiveness remains unknown. In this study, three bare-metal stents (BMSs) and three sirolimus-eluting stents (SESs) were implanted in 1-month-old pigs. The pigs were killed 8 weeks later to compare in-stent stenosis rates. The extent of neointimal thickness, as measured by injury score, was significantly less in the SES group than in the BMS group (injury score 1: BMS 0.351 + or - 0.033 vs SES 0.226 + or - 0.031 mm; P < 0.01; injury score 2: BMS 1.232 + or - 0.244 vs SES 0.609 + or - 0.208 mm; P < 0.01). The pathologic findings showed confluence of inflammatory cells around the stent wires in BMS-treated areas and granuloma formation. Granuloma formation was not seen with SES. The degree of in-stent stenosis was significantly reduced in the SES group, suggesting that the use of drug-eluting stents is an effective treatment for PVS. Because of the small sample size and the considerable variation in injury scores and balloon-to-vein ratios, future studies with larger samples are necessary.

Histological findings after angioplasty using conventional balloon, radiofrequency thermal balloon, and stent for experimental aortic coarctation.

BACKGROUND: Use of balloon angioplasty or stent implantation has been reported to be effective in relieving coarctation of the aorta. However, restenosis frequently occurs after balloon angioplasty for native aortic coarctation in small infants, and sometimes develops after stent implantation because of vessel growth. The causes of restenosis remain uncertain. The purpose of this study was to assess the histologic differences in vascular responses to angioplasty using conventional balloon, radiofrequency thermal balloon (RFTB), or stent for experimental aortic coarctation. METHODS: The authors surgically created an aortic coarctation model using 14 puppies. Angioplasty using conventional balloon, RFTB, or stent was performed 1 month after the initial operation. At the acute or chronic phase after angioplasty, the animals were killed and histologic studies were performed. RESULTS: More vascular injuries were noted in the specimens from animals undergoing conventional angioplasty than in those with RFTB or stent. However, neointimal hyperplasia was seen more often after RFTB or stent because of the proliferation of smooth muscle cells from the tunica media, caused by secretion of growth factors. Apoptosis reached a peak 1-2 weeks after angioplasty, regardless of the type of intervention. CONCLUSIONS: The authors conclude that angioplasty with RFTB or stent can provide relatively small injuries in the vessel wall for aortic coarctation, but care must be taken to prevent restenosis caused by intimal hyperplasia, because neointima hyperplasia is more frequent after RFTB or stent.

Fecal alpha1-antitrypsin concentrations as a measure of enteric protein loss after modified fontan operations.

BACKGROUND: Little is known about the enteric protein loss in patients after a modified Fontan operation before the appearance of overt symptoms or signs of protein-losing enteropathy (PLE). The authors examined the possibility of using fecal alpha1-antitrypsin concentration measurements for the early detection of postoperative PLE and in longer term postoperative monitoring of these patients. METHODS: The authors compared fecal alpha1-antitrypsin concentrations in stool samples from 12 children 12.0 to 43.7 months after modified Fontan operations with those of 12 age-matched control subjects and examined the relationship between the alpha1-antitrypsin levels and time since operation. The authors also compared fecal alpha1-antitrypsin concentrations of stools from the same patients obtained at two different time points after surgery with intervals between samples ranging from 14.7 to 19.8 months. RESULTS: No significant differences in serum total protein and albumin levels were observed between patients after the modified Fontan operation and control subjects. The fecal concentrations of alpha1-antitrypsin in patients after the Fontan operation were significantly (P < 0.01) higher than those in control subjects. There was no significant correlation between fecal alpha1-antitrypsin concentrations and time elapsed after the Fontan operation. The fecal alpha1-antitrypsin concentration increased significantly (P < 0.01) over periods of 14.7 to 19.8 months after the first measurement. CONCLUSION: The results show that enteric protein loss begins before the appearance of hypoproteinemia in patients after a modified Fontan operation, and that the measurement of fecal alpha1-antitrypsin concentrations in random stool samples is useful as an early indicator. To watch for the development of PLE after Fontan operation, it may be important to perform longitudinal follow-up examinations of enteric protein loss by measuring fecal alpha1-antitrypsin concentrations early in the postoperative period.