Lee N Benson

University of Toronto, Toronto, Ontario, Canada

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Publications (374)1908.08 Total impact

  • Eric Horlick · Lee Benson
    Circulation Cardiovascular Interventions 12/2015; 8(1). DOI:10.1161/CIRCINTERVENTIONS.114.002208 · 6.22 Impact Factor
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    ABSTRACT: While well characterized in adult patients, the pattern of hypertrophy and the extent of myocardial scarring in hypertrophic cardiomyopathy (HCM) are insufficiently known. The aim of this study was to assess the hypertrophy patterns and the prevalence and clinical significance of scars in the hearts of young patients with HCM. A retrospective analysis of the imaging findings of 38 children (aged 12.83 ± 2 years, 30 males) with HCM who underwent cardiac magnetic resonance imaging (CMR) was performed. In addition to left ventricular mass and volumes, the examinations were assessed for the pattern of hypertrophy and presence of late gadolinium enhancement (LGE). A myocardial signal intensity ≥6 standard deviations above the mean of normal myocardium defined positive LGE. Left ventricular mass index averaged 110 ± 34 g/m(2) . Nineteen children (50%) had diffuse septal, 13 (34%) diffuse concentric and 6 (16%) isolated basal hypertrophy. Seven children (18%) had LGE. Patients with LGE had a greater left ventricular mass index than those without (136 ± 34 g/m(2) vs. 104 ± 31 g/m(2) , P = .025). The only two patients who presented with an episode of aborted sudden cardiac death had LGE (P = .03). The most common hypertrophy pattern in children with HCM was diffuse septal hypertrophy. The incidence of LGE observed is lower than that reported in adults. The presence of LGE appears to confer a risk for adverse events. © 2015 Wiley Periodicals, Inc.
    Congenital Heart Disease 07/2015; DOI:10.1111/chd.12286 · 1.08 Impact Factor
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    ABSTRACT: Sirolimus-eluting stents may have clinical advantages over bare-metal stents in the extremely proliferative environment of the neonatal arterial duct. However, sirolimus has immunosuppressive actions and little is known regarding sirolimus pharmacokinetics in the newborn. This is a retrospective review of sirolimus pharmacokinetics in neonates who underwent sirolimus-eluting stent implantation in the arterial duct for pulmonary blood flow augmentation. Pharmacokinetic parameters were obtained by noncompartmental analysis and by a Bayesian one-compartment nonlinear mixed model. Nine neonates received a single sirolimus-eluting stent with a total sirolimus dose of 245 μg (n=1), 194 μg (n=5), or 143 μg (n=3). Peak sirolimus concentrations were 13.6±4.5 μg/L (24.8 μg/L highest) and clearance was 0.042±0.03 L/hour (noncompartmental analysis) and 0.051 L/hour (95% credible intervals 0.037-0.069, nonlinear mixed model). Sirolimus remained >5 μg/L, the trough level used in oral immunosuppressive therapy, for (95% credible interval) 15.9 (11.4, 22.8), 12.9 (7.6, 19.0), and 8.4 (2.3, 14.5) days for the 245, 194, and 143 μg sirolimus dose stents, respectively. Estimates of the duration of systemic immunosuppression are provided for combinations of 2 stents. In neonates after sirolimus-eluting stent implantation, peak sirolimus levels were 20× higher and clearance 30× lower than previously reported in older children and adults. Sirolimus levels were within the immunosuppressive range for a prolonged period, but with no observable clinically significant adverse outcomes. © 2015 American Heart Association, Inc.
    Circulation Cardiovascular Interventions 05/2015; 8(5). DOI:10.1161/CIRCINTERVENTIONS.114.002233 · 6.22 Impact Factor
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    ABSTRACT: Objectives To assess the effectiveness of radiation-reduction measures implemented during pediatric catheterization, and provide data on the radiation doses for common interventional and diagnostic procedures, indexed to body weight.Background Ionizing radiation exposure must be minimized to “as low as reasonably achievable,” by instituting radiation-limiting techniques and knowledge of expected radiation exposure.Methods Radiation-reduction measures included pulsed-fluoroscopy at 7.5 pulses/second (0.032–0.045 µGy/pulse), an air-gap magnification technique for children <20 kg, operator awareness, and additional exposure reduction techniques through projection optimization. Radiation doses for procedures performed between 2007 through 2014 were retrospectively reviewed, including dose area product (DAP) and DAP/kg of body weight for 25 procedural types. Median doses were compared with those previously published from other large centers and multi-institutional databases and assessed for changes over time.ResultsReviewed were 5,196 cases, which included 2,819 interventional, 710 endomyocardial biopsies and 1,667 diagnostic studies, documenting a significant difference in exposure between various procedures and body weights. The absolute exposure was significantly greater in larger children (e.g., for ductal closure median DAP/kg: 17 µGy*m2/kg 10–20 kg children vs. 37 µGy*m2/kg for those >30 kg, P < 0.001). Dose exposure using radiation-reduction techniques were the lowest reported in the literature for all procedure types compared (e.g. median DAP for pulmonary valvuloplasty 163 µGy*m2vs. 405 to 1,230 µGy*m2 reported by 3 large centers). Reduction of fluoroscopy acquisition to 7.5 pulses/second nearly halved radiation exposure (P < 0.001).Conclusions Implementing a radiation dose reduction and awareness program can lead to documented reduction in exposure, across a variety of procedures performed by multiple operators. © 2015 Wiley Periodicals, Inc.
    Catheterization and Cardiovascular Interventions 05/2015; DOI:10.1002/ccd.26024 · 2.11 Impact Factor
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    ABSTRACT: The aim of the study was to examine the role of three-dimensional rotational angiography (3DRA) in assessing vascular and airway narrowing in children with a bidirectional cavopulmonary anastomosis (BCPA). The course of children with single ventricle physiology is often complicated by left pulmonary artery (LPA) and/or bronchial stenosis and may be related to aortic compression. 3DRA may be useful in evaluating this complex anatomy and possible mechanisms for the observed obstruction. Clinical data and imaging (2D angiography and 3DRA) of children with a BCPA were reviewed retrospectively. Measurements were taken at similar locations along the pulmonary arteries in both modalities and in the airways on 3DRA. Twenty-five children with a previous BCPA were assessed at mean age of 3.1 ± 2.0 years and weight of 13.6 ± 3.6 kg. Excellent correlation was found between 3DRA and 2D angiographic LPA measurements (r = 0.89, p < 0.0001). Twelve children had qualitative LPA stenosis on 3DRA, with a stenotic dimension of 6.6 ± 2.2 mm on 2D angiography and 6.8 ± 1.9 mm on 3DRA (r = 0.94, p < 0.0001). Ten cases with LPA stenosis also had bronchial stenosis (83 %). Qualitative airway assessment correlated with quantitative bronchial dimensions from 3DRA-derived tomographic images: Bronchial stenosis measured 4.4 ± 1.6 versus 5.9 ± 1.1 mm in those with a normal appearing bronchus (p = 0.009). Hybrid patients (initial palliation with bilateral pulmonary artery banding and arterial ductal stenting, n = 5) and all patients with a Damus-Kaye-Stansel (DKS) anastomosis (n = 9) were more likely to have LPA and left bronchial stenosis (OR 7.7, p = 0.04). 3DRA is a useful and accurate tool in assessment of LPA and airway narrowing after BCPA. Hybrid and DKS patients are more prone to LPA and bronchial stenosis, and 3DRA can provide insight into the mechanism.
    Pediatric Cardiology 03/2015; 36(5). DOI:10.1007/s00246-015-1130-8 · 1.31 Impact Factor
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    ABSTRACT: To report procedural characteristics and adverse events on data collected in the registry. The IMPACT - IMproving Paediatric and Adult Congenital Treatment - Registry is a catheterisation registry of paediatric and adult patients with CHD undergoing diagnostic and interventional cardiac catheterisation. We are reporting the procedural characteristics and adverse events of patients undergoing diagnostic and interventional catheterisation procedures from January, 2011 to March, 2013. Demographic, clinical, procedural, and institutional data elements were collected at the participating centres and entered via either a web-based platform or software provided by American College of Cardiology-certified vendors, and were collected in a secure, centralised database. Centre participation was voluntary. During the time frame of data collection, 19,797 procedures were entered into the IMPACT Registry. Procedures were classified as diagnostic only (35.4%); one of six specific interventions (23.8%); other or multiple interventions (40.7%); and were further broken down into four age groups. Anaesthesia was used in 84.1% of diagnostic procedures and 87.8% of interventional ones. Adverse events occurred in 10.0% of diagnostic and 11.1% of interventional procedures. The IMPACT Registry is gathering data to set national benchmarks for diagnostic and certain specific interventional procedures. We are seeing little differences in procedural characteristics or adverse events in diagnostic procedures compared with interventional procedures overall, but there is significant variation in adverse events amongst age categories. Risk stratification and patient acuity scores will be required for further analysis of these differences.
    Cardiology in the Young 02/2015; -1:1-9. DOI:10.1017/S1047951114002637 · 0.84 Impact Factor
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    ABSTRACT: Objectives This study was designed to compare outcomes of the most common pediatric cardiac interventions from the time of implementation with the current era.Background Since the introduction of semilunar valve balloon dilation and device closure of the arterial duct and septal defects, development of interventional techniques and devices has been rapid. However, few studies have compared outcomes between those initial interventions and those in the current era.Methods Five validated common catheter-based therapies were chosen for analysis, including atrial and duct device closure, balloon dilation of the aortic and pulmonary valves, and native coarctation of the aorta. A retrospective review of the first and most recent 10 consecutive patients in each group was performed.ResultsThere was a high mortality (30%) among neonates who underwent aortic valve (AV) dilation in the early era, but no mortality noted in other groups. In the early era, transcatheter atrial defect closure and AV dilations were associated with a low success rate (60% for both lesions) and a high complication rate (40% for atrial septal defect, 30% for AV dilations). Among the last 10 children, the atrial defect occlusion was successful in 100% without complications and AV dilations where successful in all children with a 30% complication rate (one major, two minor).ConclusionsA learning curve with device development plays a significant role in the evolution of transcatheter techniques. These data provide baseline estimates of success and may be used as a template in the future when new techniques are adapted into practice.
    Congenital Heart Disease 02/2015; 10(4). DOI:10.1111/chd.12247 · 1.08 Impact Factor
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    ABSTRACT: Percutaneous pulmonary valve implantation (PPVI) is a safe, less invasive alternative to surgical valve replacement for the congenital heart disease patient with right ventricular (RV) outflow tract dysfunction. The aim of this study was to determine whether reverse RV remodeling after PPVI was persistent in the longer term and whether timing of PPVI influenced outcomes. Consecutive patients from the pediatric and adult congenital heart disease programs were enrolled. Cardiac MRI, echocardiography, metabolic exercise testing, chest radiography, and hemodynamics before intervention were compared with repeated follow-up measurements to assess changes over time. Fifty-one patients (including 23 patients <16 years old) were followed for a mean 4.5±1.9 (0.9-6.9) years after implantation, 59% of patients having available comparative cardiac MRI data. Freedom from any reintervention was 87% and 68% at 3 and 5 years, and freedom from surgery was 90% at 5 years. For every decade younger at implantation, there was an increase of 3.9%±1.0% in cardiac MRI left ventricular ejection fraction (P<0.001) and 2.4±0.9 mL/kg/min in maxVO2 (P=0.005) and a decrease of 0.7±0.2 cm in RV end-diastolic dimension (P<0.001) after intervention. Younger patients displayed an additional decline in the RV/left ventricular end-diastolic volume ratio (P=0.05) and trended toward improved RV ejection fraction in late follow-up (50%±7% versus 41%±12%, P=0.07). This is the largest series to show that PPVI at a younger age yields incremental improvements in RV size and maximum oxygen consumption. Early valve implantation is associated with better RV function and should be considered in management planning for this population. © 2015 American Heart Association, Inc.
    Circulation Cardiovascular Interventions 02/2015; 8(2). DOI:10.1161/CIRCINTERVENTIONS.114.001745 · 6.22 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the presence of diffuse myocardial fibrosis in children and adolescents with hypertrophic cardiomyopathy (HCM) and to assess associations with echocardiographic and clinical parameters of disease. While a common end point in adults with HCM, it is unclear whether diffuse myocardial fibrosis occurs early in the disease. Cardiac magnetic resonance (CMR) estimation of myocardial post-contrast longitudinal relaxation time (T1) is an increasingly used method to estimate diffuse fibrosis. T1 measurements were taken using standard multi-breath-hold spoiled gradient echo phase-sensitive inversion-recovery CMR before and 15 min after the injection of gadolinium. The tissue-blood partition coefficient was calculated as a function of the ratio of T1 change of myocardium compared with blood. An echocardiogram and blood brain natriuretic peptide (BNP) levels were obtained on the day of the CMR. Twelve controls (mean age 12.8 years; 7 male) and 28 patients with HCM (mean age 12.8 years; 21 male) participated. The partition coefficient for both septal (0.27 ± 0.17 vs. 0.13 ± 0.09; p = 0.03) and lateral walls (0.22 ± 0.09 vs. 0.07 ± 0.10; p 100 pg/ml) had raised lateral wall coefficients (0.27 ± 0.07 vs. 0.20 ± 0.07; p = 0.03), as did those with traditional risk factors for sudden death (0.27 ± 0.06 vs. 0.18 ± 0.08; p = 0.007). Diffuse fibrosis, measured by the partition coefficient technique, is demonstrable in children and adolescents with HCM. Markers of fibrosis show an association with symptoms and raised serum BNP. Further study of the prognostic implication of this technique in young patients with HCM is warranted.
    Pediatric Cardiology 01/2015; 36(5). DOI:10.1007/s00246-015-1107-7 · 1.31 Impact Factor
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    ABSTRACT: Valve pathology is a significant component of pediatric cardiovascular disease. Outside the pediatric age group, patients are selecting bioprosthetic valve replacements to avoid the obligate anticoagulation associated with mechanical valves either because of the inability to take anticoagulation, pregnancy considerations, or preference. Bioprosthetic valves, however, inevitably degenerate. The standard treatment is a repeat operation that entails additional risk. Transcatheter valve therapy has rapidly emerged as an appealing alternative. In this manuscript, we discuss the progress in transcatheter valve-in-valve (VinV) procedures. This is essential knowledge for the practicing pediatric cardiologist as it may promote the application of bioprosthetic valves as a treatment option and management strategy.
    Progress in Pediatric Cardiology 01/2015; 38(1-2). DOI:10.1016/j.ppedcard.2014.12.010
  • W. Wilson · A. Shah · L. Benson · M. Osten · E. Horlick
    Heart, Lung and Circulation 01/2015; 24:S432-S433. DOI:10.1016/j.hlc.2015.06.744 · 1.44 Impact Factor
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    ABSTRACT: The National Cardiovascular Data Registry (NCDR) launched the IMPACT (Improving Pediatric and Adult Congenital Treatment) Registry in 2010. By 2013, its patient enrollment exceeded that of other current and historical congenital catheterization registries. This study sought to describe procedural results and safety of 6 common congenital interventions performed in patients enrolled during the IMPACT Registry's initial periods. With specified exclusions, we compiled registry data from patients enrolled in the IMPACT Registry from January 2011 through March 2013 who underwent 1 of the following isolated procedures: device closure of atrial septal defect (ASD); device closure of patent ductus arteriosus (PDA); pulmonary valvuloplasty; aortic valvuloplasty; coarctation of the aorta angioplasty and stenting; and pulmonary artery stenting. Patient data, procedural data and results, and adverse events (AEs) were reviewed and described. In 4,152 catheterizations, 1 isolated procedure was reported. There were 1,286 single-ASD procedures, 1,375 PDA procedures, 270 "typical" pulmonary valve procedures, 305 aortic valve procedures, 671 aortic procedures, and 245 pulmonary artery procedures. The reported procedure was performed in >95% of catheterizations. Stated outcomes were accomplished in >98% of ASD and PDA procedures, but less commonly in the others, with coarctation angioplasty procedures being the least successful (51%). Reported major AE rates ranged from 0% to 3.3%; total AE rates ranged from 5.3% to 24.3%. Contemporary community practice, procedural outcomes, and safety for 6 common congenital interventional procedures are reported. These benchmarks may be compared with individual center results and historical single-center and multicenter results. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    Journal of the American College of Cardiology 12/2014; 64(23):2439-51. DOI:10.1016/j.jacc.2014.09.045 · 16.50 Impact Factor
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    ABSTRACT: Pulmonary artery growth is an important determinant of outcome in single-ventricle strategies. Higher rates of pulmonary artery intervention have been reported with hybrid-based palliation when compared with Norwood palliation. We performed a retrospective review of pulmonary artery growth and clinical outcomes in patients undergoing hybrid-based single-ventricle palliation. The stage I hybrid procedure was performed in 72 patients between 2004 and 2012, of whom 54 were on a Fontan palliative pathway. Thirty-four infants completed stage II, and 20 infants underwent the Fontan operation. The mean diameters of the right pulmonary artery (5.6 ± 1.9 mm) and left pulmonary artery (5.6 ± 2.1 mm) were similar before stage II. After stage II, the right and left pulmonary artery diameters were 8.5 ± 2.1 mm and 5.8 ± 1.3 mm, respectively (P < .001), and after the Fontan operation, these were 8.8 ± 2.0 mm and 6.4 ± 1.1 mm, respectively (P = .002). The mean right pulmonary artery z score was normal throughout, but the left pulmonary artery did not maintain a normal size. The cumulative pulmonary artery intervention rate was 50% at any time after stage II. Fifteen interventions (88%) were performed after stage II (35% during the same hospitalization, 71% <60 days). The most intervened site was the midsection of the left pulmonary artery (41%). Initial pulmonary artery intervention was balloon dilation in 59% of patients and stent implantation in 41% of patients. Half of patients with initial balloon dilation required reintervention. There is significant risk of left pulmonary artery compromise after the second stage of hybrid palliation associated with a high intervention rate. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
    Journal of Thoracic and Cardiovascular Surgery 12/2014; 149(4). DOI:10.1016/j.jtcvs.2014.11.080 · 4.17 Impact Factor
  • W. Wilson · E. Horlick · L. Benson
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    ABSTRACT: We describe a case of a Scimitar syndrome “variant” where dual drainage existed from the right upper and middle pulmonary veins to the inferior vena cava and left atrium. Device closure of the anomalous vein at the level of the connection to the IVC was successful in achieving diversion of pulmonary venous flow to the left atrium. Vigilance during work-up of anomalous pulmonary venous drainage (whether isolated or associated with other cardiac defects that may be amenable to device closure) is important to define the presence of dual connections to the left atrium, in which case a less-invasive transcatheter approach may be feasible. © 2014 Wiley Periodicals, Inc.
    Catheterization and Cardiovascular Interventions 11/2014; 85(7). DOI:10.1002/ccd.25734 · 2.11 Impact Factor
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    ABSTRACT: Pediatric and Congenital Interventional Cardiology is the practice of catheter‐based techniques that improve cardiac physiology and circulation through the treatment of heart disease in children and adults with congenital or acquired heart defects. Over the last decade, and since last published training guidelines for pediatric cardiac catheterization and interventional cardiology were published in 2005 [1] the field of Pediatric and Congenital Cardiac Catheterization has evolved into a predominantly interventional discipline. As there is no sub‐specialty certification for interventional cardiac catheterization in pediatrics, the Congenital Heart Disease Committee of the Society of Cardiovascular Angiography and Interventions has put together this consensus statement for advanced training in pediatric and congenital interventional cardiac catheterization. The statement puts forth recommendations for program infrastructure in terms of teaching, personnel, equipment, facilities, conferences, patient volume and trainee assessment. This is meant to set a standard for training programs as well as giving applicants a basis on which to judge and compare programs. © 2014 Wiley Periodicals, Inc.
    Catheterization and Cardiovascular Interventions 11/2014; 84(5). DOI:10.1002/ccd.25550 · 2.11 Impact Factor
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    ABSTRACT: Objectives We sought to review our single center experience with secundum atrial septal defect (ASD) device closure, evaluating the incidence and morphological characteristics where percutaneous closure was thought inappropriate. Material and methodsAll children assessed as unsuitable for transcatheter device closure were reviewed. Data collected included: demographics, defect morphology by echocardiogrphy or at cardiac catheterization and defect size focusing on the reasons for procedural deferral. ResultsBetween January 2002 and December 2010, 639 children underwent closure of an isolated secundum ASD: 82 children (13%) where referred directly to surgery, 43 (6%) were thought unsuitable for device closure at the time of catheterization and underwent subsequent surgery and the remaining 514 (81%) underwent successful device closure including 2 on a second attempt. The reasons for pursuing a surgical closure (n=124, mean age=5.7 years; range: 0.6-17.4 years; defect diameter/body weight=1.39) included: the need for a device thought too large for implantation versus the child's size (n=51), defects with deficient rim(s) (n=48), multiple defects (n=7), defects sized >36 mm (n=2), malposition (n=2), ECG changes (n=3), aneurysmal IAS (n=2), sinus venosus (n=2), or others (n=7). Conclusion The reasons for deferring transcatheter device closure of a secundum ASD are diverse, not only isolated rim deficiencies but the requirements of large implants, malposition, arrhythmias, and lack of hemodynamic need are influential components in clinical decision making. (c) 2014 Wiley Periodicals, Inc.
    Catheterization and Cardiovascular Interventions 10/2014; 85(2). DOI:10.1002/ccd.25700 · 2.11 Impact Factor
  • William Wilson · Mark Osten · Lee Benson · Eric Horlick
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    ABSTRACT: As increasing numbers of patients with congenital heart disease enter adulthood, there is a growing need for minimally invasive percutaneous interventions, primarily to minimize the number of repeated surgeries required by these patients. The use of percutaneous devices is commonplace for the treatment of simple lesions, such as atrial septal defect, patent foramen ovale, patent duct arteriosus, and abnormal vascular connections. There is also substantial experience with device closure of membranous and muscular ventricular septal defects, as well as more complex shunts such as baffle leaks after atrial switch repair and ventricular pseudoaneurysms. An increasing use of covered stents has improved the safety of aortic coarctation, conduit, and branch pulmonary stenosis interventions. Percutaneous pulmonary valve implantation now has an established role in the setting of dysfunctional right ventricle-pulmonary artery conduits or failing bioprosthetic pulmonary valves. Many patients remain unsuitable for percutaneous pulmonary valve implantation because of large diameter "native" outflow tracts, however, various techniques have emerged and multiple devices are in development to provide solutions for these unique anatomic challenges. Hybrid approaches involving use of surgical and transcatheter techniques are increasingly common, serving to optimize efficacy and safety of certain procedures; they depend on a collaborative and collegial relationship between cardiac surgeons and interventionalists that is primarily patient-centred.
    The Canadian journal of cardiology 01/2014; 30(1):75-86. DOI:10.1016/j.cjca.2013.11.006 · 3.94 Impact Factor
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    Andrea W Wan · Kyong-Jin Lee · Lee N Benson
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    ABSTRACT: Covered stents have been used for the treatment of aortic coarctation to protect the arterial wall during dilation. Early results have shown them to be safe and effective. We report 2 cases of infolding of the proximal edge of a covered aortic coarctation stent. Management required implantation of a second stent. Poor stent apposition to the vessel wall and or recoil may allow conditions for these events to occur. © 2013 Wiley Periodicals, Inc.
    Catheterization and Cardiovascular Interventions 01/2014; 83(1). DOI:10.1002/ccd.24998 · 2.11 Impact Factor
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    ABSTRACT: Hypertrophic cardiomyopathy (HCM) is the most common form of inherited cardiomyopathy. Echocardiography is the mainstay of screening and disease surveillance, and genetic testing has identified a carrier population without hypertrophy. The aim of this study was to investigate whether changes in left ventricular (LV) function are detectable before the advent of hypertrophy. Fourteen children with genotype-positive, phenotype-negative HCM were identified (12 male; median age, 9.14 years; range, 1.91-15.9 years; median weight, 34.6 kg; range, 15-92.1 kg) and compared with age-matched and sex-matched healthy controls. All children underwent full echocardiographic studies using an extensive functional protocol, including two-dimensional dimensions, Doppler tissue imaging, and two-dimensional speckle-tracking echocardiography. There were no differences in LV wall thickness, chamber dimensions, length, and shortening fraction between the groups. Doppler tissue imaging in children with HCM demonstrated mildly reduced septal velocities, notably A' (5.9 cm/sec [range, 4-8.9 cm/sec] vs 6.7 cm/sec [range, 5.2-9.5 cm/sec]; P = .009). Circumferential and longitudinal strain was similar between groups. Mean apical circumferential deformation was increased in the HCM group (-24.6 ± 3.8% vs -22.2 ± 2.5%, P = .04). There were significant increases in basal and apical rotation and LV twist in children with HCM, most marked at the apex (11.7 ± 4.4° vs 5.3 ± 2.5°, P = .0001). On receiver operating characteristic curve analysis, apical rotation > 7° conferred 83% sensitivity and 82% specificity for predicting HCM (area under the curve, 0.919; P = .0001). Increased LV rotation and twist are present in children with genotype-positive, phenotype-negative HCM. Apical rotation on speckle-tracking echocardiography provides good sensitivity and specificity for the prediction of gene-positive HCM and may be a clinically useful early marker of HCM before the onset of hypertrophy.
    Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 12/2013; 27(2). DOI:10.1016/j.echo.2013.10.012 · 4.06 Impact Factor
  • The Canadian journal of cardiology 10/2013; 29(10):S97. DOI:10.1016/j.cjca.2013.07.118 · 3.71 Impact Factor

Publication Stats

9k Citations
1,908.08 Total Impact Points


  • 1985–2015
    • University of Toronto
      • • Labatt Family Heart Centre
      • • Department of Paediatrics
      • • Division of Cardiology
      • • Hospital for Sick Children
      • • Department of Medicine
      • • Faculty of Medicine
      Toronto, Ontario, Canada
  • 1981–2015
    • SickKids
      • • Division of Cardiology
      • • Division of Clinical Pharmacology and Toxicology
      • • Department of Paediatrics
      • • Department of Diagnostic Imaging
      Toronto, Ontario, Canada
  • 2013
    • The Bracton Centre, Oxleas NHS Trust
      Дартфорде, England, United Kingdom
  • 1987–2008
    • UHN: Toronto General Hospital
      Toronto, Ontario, Canada
  • 2007
    • University Health Network
      Toronto, Ontario, Canada
  • 1986–1995
    • Toronto Western Hospital
      Toronto, Ontario, Canada
  • 1993
    • Hackensack University Medical Center
      Хакенсак, New Jersey, United States