Coronary artery (CA) aneurysms are serious complications of Kawasaki disease (KD) responsible for ischemic events. Percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are reported with limited data on indications and comparative efficacy. Retrospective multicenter comparison of CA intervention following KD is performed in this study. Twenty two cases were available from 5 centers, of whom 11 underwent CABG, 10 PCI and 1 systemic thrombolysis. Age at intervention (8.3 ± 3.9 vs 11.3 ± 4.9 years, p = 0.14) and interval from diagnosis (5.6 ± 4.1 vs 6.5 ± 4.7 years, p = 0.64) were similar between CABG and PCI. Interventions were based on angiography in 15 patients or cardiac event in 7, with no difference between CABG and PCI (p = 0.24). Patients with CABG were more likely to undergo multivessel intervention (73 vs 10 %, p = 0.006). None of the patients needed reintervention after CABG, compared to 6 after PCI and 1 after systemic thrombolysis (p = 0.004). Signs of ischemia on stress testing or MIBI were present in 15 patients before intervention and persisted in 9 patients following last intervention, in a significantly higher proportion after CABG than PCI (80 vs 17 %, p = 0.01). In this series, CABG, which mostly involved multivessel intervention, was superior to PCI. Nevertheless, larger-scale studies may help define patient selection criteria for a beneficial PCI approach.

PAH is a severe disease, in which pulmonary arterial remodeling leads to an increase in pulmonary vascular resistance and pulmonary arterial pressure, eventually resulting in right ventricular failure and death. Epidemiology and understanding of PAH in pediatric patients remains poorly understood. In an effort to expand knowledge of pediatric PAH in Canada, a prospective, observational registry of pediatric patients with PAH was established in May 2010 including all eleven academic pediatric cardiac centers across Canada. The main objective is to describe demographics and disease characteristics, incidence and prevalence and outcomes. Criteria for enrollment: age between 3 months and 17 years, PAH WHO Group 1 confirmed by right heart catheterization with following hemodynamics: Mean pulmonary artery pressure ≥ 25mm Hg at rest and pulmonary arterial wedge pressure ≤ 15 mm Hg. Both incident patients (PAH diagnosed within 4 months of enrollment in the study) and prevalent patients (diagnosis more than 4 months prior to enrollment in the study) were screened. Patients with persistent pulmonary hypertension of the newborn were not eligible. A total of 80 patients have been enrolled between May 1 2010 and April 30 2015. The median age was 2 years range from (<1 to 17 years), 54 female and 26 male. Mean pulmonary artery pressure at presentation ranged from 12 to 89 mm Hg (mean 46.4 mm Hg, median 44 mm Hg). Pulmonary vascular resistance (indexed for body surface area) ranged from 2.6 to 45 WUxm2 (mean 11.7, median 8.0 WUxm2). Documented follow-up visits were established for 11 patients (1 visit), 16 patients (2 visits), 19 patients (3 visits), 2 patients (4 visits) and 1 patient (5 visits). Predominantly female patients were enrolled in the Canadian Pediatric PAH registry; patients are relatively young in age and present with higher mean pulmonary artery pressures and pulmonary vascular resistance compared to adults. Future follow-up data will provide insight into survival.

Coronary artery (CA) aneurysms are a serious complication following Kawasaki disease (KD). Approximately half of aneurysms more than 6 mm will develop stenosis by 15 years follow-up. Stenosis is responsible for ischemic heart disease and sudden death. Experience with percutaneous coronary intervention (PCI) and coronary artery bypass grafts (CABG) have previously been described. However, there are limited data on the indications, comparative efficacy and long-term outcome. This multicenter study enrolled academic pediatric cardiology centers in Canada to identify patients who had coronary artery interventions following KD. Patients' charts were retrospectively reviewed for clinical courses with echocardiography, stress testing, angiography, interventional catheterization and cardiac surgery. We sought to describe coronary interventions performed in Canada, the indication for procedure and patients' outcome. From 12 centers, 6 (50%) had cases with CA interventions, and 5/6 reported their experience in this study. There were 22 reported patients age 10.6±5.8 years (range 2.1-26.2) at time of intervention, 6.9±6.1 years after KD diagnosis. Post intervention follow-up was 3.6±3.1 years. PCI was performed in 10 (45%) patients and CABG in 12 (55%) (multi-vessel in 9). There was a marked difference in the choice of procedure between centers (p=0.038). Interventions were performed based on angiography findings in 15/22 patients (68%) or following a cardiac event in 7/22 patients (32%), without significant differences between centers (p=0.810). Before intervention, 14 cardiac events occurred in 9/22 (41%) patients, 3.3±4.0 years after KD onset. Only 10 events (67%) led to cardiac intervention (PCI, CABG or systemic thrombolysis), in 7/22 (32%) patients. Signs of ischemia were present in 15/22 patients (68%) before intervention, either on stress testing in 8 (36%) and/or MIBI in 8 (36%) patients. After initial intervention, 6 patients (60%) required reintervention at 1.7±1.1 years following PCI, and none following CABG (p=0.003). Following last intervention, 9 patients (41%) still had signs of ischemia on stress testing or MIBI (25% PCI vs. 67% CABG patients; p=0.17). Finally, 1 patient sustained a sudden cardiac death, 7.4 year after last PCI. In this Canadian series, there was marked variation between centers regarding the indications and choice of intervention for revascularization. CABG, which was mostly multi-vessel, did not require reintervention, whilst PCI had the advantage of better subsequent myocardial perfusion imaging. In the absence of established guidelines, larger scale studies are required to inform risk stratification and guide therapeutic approaches.

The aim of this study was to determine the incidence of Acute Rheumatic Fever (ARF) between the First Nation (FN) and non First Nation (n-FN) children in the Province of Manitoba, Canada.

Clinical pediatric cardiology practice in Manitoba has observed a non-aboriginal/Caucasian predisposition in the presentation of dextro-Transposition of the Great Arteries (D-TGA). In contrast to D-TGA, native Manitoba aboriginals were observed to have a predisposition to Total Anomalous Pulmonary Venous Return (TAPVR). We sought to determine if a unique distribution of congenital heart disease exist in Manitoba. Retrospective review of all pediatric patients diagnosed with any form of D-TGA and TAPVR from 1991-2010 in Manitoba was undertaken. Epidemiological parameters were collected. Ethnicity was collected on a self-identification basis: aboriginal (First Nation/Metis/Inuit) versus non-aboriginal. Birth rates were collected from statistics Canada. Odds ratio calculations using 5-year moving rates were used to compare groups. Ninety-three percent (93/100) of D-TGA patients were non-aboriginal with a incidence of 1 in 2866 live births compared to 1 in 7620 for Aboriginals (Odds Ratio 2.3, 95% CI 1.12-4.74, p=0.024). In TAPVR 59 % (29/57) of patients were aboriginal with an incidence of 1 in 1838 live births, compared to 1 in 10253 in non-aboriginals (Odds ratio 5.58, 95% CI 3.28-9.47), p < 0.0001). In isolated TAPVR, without any complex concomitant abnormalities or heterotaxia syndromes, the aboriginal odds ratio was 8.57 (95% CI 4.43-16.57, p<0.0001). Clinically and statistically, TAPVR was significantly more common in Manitoba aboriginals, compared to non-aboriginals. The occurrence of D-TGA was observed to be almost 2 times less likely in the Manitoban Aboriginal populace studied. This distinct pattern of congenital heart disease warrants future research to investigate the epidemiological factors and/or genetic etiology causing these observed ethnical differences.

Supra-valvular pulmonary stenosis (SVPS) is the most common complication after Arterial Switch Operation (ASO) for D-Transposition of the Great Arteries (D-TGA) in neonates. While the majority improve over time some require re-intervention to relieve symptomatic lesions. We hypothesize that early post-operative echocardiography will predict which patients are at higher risk of re-intervention for significant SVPS following ASO. Retrospective review of Manitoba newborns (n=63) who had ASO for D-TGA from 1991-2010. First post-operative- and most recent trans-thoracic echocardiograms (TTE) of all surviving patients (n=59) were reviewed for SVPS. Patients were categorized as needing re-intervention for SVPS ("re-intervention"-group) versus those who did not ("no re-intervention"-group). Univariate analysis using Fisher's Exact Test was used to analyze parameters summarized in table 1. Significant TTE parameters (gradients > 40mm Hg plus 2 or more levels of stenosis) were analyzed using the Kaplan-Meier method to calculate probability of freedom from re-intervention.Tabled 1 Mean follow-up period was 9.8 (SD+-6) years. First post-operative TTE demonstrating 2 or more levels of stenosis, stenosis gradients > 40mm Hg, both last mentioned parameters combined, as well as D-TGA plus VSD, were all significantly more prevalent in the "re-intervention"-group (see Table 1 below). For patients that had gradients >40 mm Hg and stenosis at 2 or more levels, the 5 year probability of freedom from re-intervention for SVPS was 40% compared to 100% for those without the two aforementioned parameters (Log Rank p=0.0001). SVPS with multiple levels of stenosis causing a gradient >40mmHg at initial TTE post-ASO, allows pediatric cardiologists to identify patients at higher risk of future re-intervention for supra-valvular pulmonary stenosis. These findings need to be validated in a larger cohort.

Study Objective. To evaluate the effectiveness and safety of enoxaparin therapy in a neonatal intensive care unit (NICU).Design. Retrospective chart review.Setting. Level III NICU in a Canadian academic center.Patients. All neonates treated with enoxaparin while in the NICU between January 1, 1998, and June 1, 2006.Measurements and Main Results. Data abstracted included patient demographics, diagnosis of thrombosis and its progression, enoxaparin dosages with corresponding antifactor Xa levels, and adverse events. Sixteen neonates (four term, 12 preterm) were treated with enoxaparin at a mean +/- SD initial subcutaneous dose of 1.41 +/- 0.15 mg/kg every 12 hours. The target therapeutic range (antifactor Xa level 0.5-1.0 U/ml) was achieved by 12 infants at a mean SD dose of 1.92 +/- 0.43 mg/kg every 12 hours, after a mean of 5.6 days (range 1-15 days). Preterm infants required a higher dose (per kilogram) compared with term infants to maintain therapeutic antifactor Xa levels (mean SD 1.94 +/- 0.39 vs 1.65 +/- 0.14 mg/kg every 12 hrs, p < 0.001). Enoxaparin doses were more strongly correlated to antifactor Xa levels in term infants (r(2)=0.51, p < 0.001) compared with preterm infants (r(2)=0.20, p < 0.001). Ten (71%) of 14 thromboembolic events resolved, either partially or completely, at a mean of 39 days (range 8-61 days) of enoxaparin therapy Nine infants (56%) experienced minor local adverse effects at the site of the indwelling subcutaneous catheter (induration, bruises, hematomas, or leakage). Systemic adverse events that were possibly related to enoxaparin therapy included osteopenia (one infant), scleral hemorrhage (one), and minor gastrointestinal tract bleeding (three) found in gastric feeding tubes. No adverse effects were associated with antifactor Xa levels greater than 1.0 U/ml.Conclusion. Enoxaparin may be effective in the treatment of neonatal thrombosis. An initial dosage of 1.5 mg/kg every 12 hours is likely inadequate to obtain therapeutic antifactor Xa levels rapidly and differs for term and preterm neonates. Therapeutic levels in preterm infants may be more variable, and the pharmacokine tics of this drug in preterm infants requires further evaluation. Future studies in neonates should prospectively evaluate a higher starting dose of enoxaparin to document effectiveness, acceptance, compliance with treatment guidelines, and adverse effects.