Predictors of mitral valve haemodynamics after mitral valve repair for degenerative mitral regurgitation.

OBJECTIVE: Intraoperative predictors of functional mitral valve (MV) stenosis after surgical repair of mitral regurgitation (MR) caused by prolapse remain poorly characterised. This study evaluated the effect of annuloplasty size on postoperative MV haemodynamics during exercise and evaluated predictors of MV hemodynamics. METHODS: 104 patients were randomly assigned to leaflet resection or preservation for surgical repair of MR in the Canadian Mitral Research Alliance CardioLink-2 study. In this post hoc analysis, we compared MV haemodynamics between the two surgical groups and examined the relationship between annuloplasty size and MV haemodynamics 1 year after repair in the combined groups. Echocardiograms were performed at baseline and intraoperatively. Exercise transthoracic echocardiography was performed 1 year postoperatively. Multivariable linear regression analysis was used to identify predictors of exercise MV gradients at follow-up. RESULTS: Mean age of participants was 65±10 years, and 83% were male. Median annuloplasty size was 34 (IQR 32-36). Dividing by the median, 48 (46%) had annuloplasty size of <34 mm and 56 (54%) had ≥34 mm. Mean and peak exercise gradients at 1 year were 11±5 mm Hg and 22±9 mm Hg in <34, and 6±3 mm Hg and 14±5 mm Hg in ≥34 (p<0.001). Rate of residual MR was similar in both groups. In multivariable analyses, annuloplasty size of ≥34 mm was associated with lower mean and peak exercise gradients at 12 months, after adjustment for repair type, age, sex, heart rate and body surface area (ß -4.1, 95% CI -6 to -3, p<0.001, and ß -7 95% CI -10 to -4, p<0.001, respectively). Intraoperative mean and peak MV gradients by transesophageal echocardiography independently predicted mean and peak resting and exercise gradients at follow-up (p<0.001). Similar results were obtained in both leaflet resection and preservation. CONCLUSION: Annuloplasty size of ≥34 mm is associated with a 4 and 7 mm Hg reduction in mean and peak exercise MV gradients, respectively, 1 year post MV repair regardless of the repair strategy used. Intraoperative TEE MV gradients predict exercise MV gradients 1 year post repair. TRIAL REGISTRATION NUMBER: NCT02552771.

Regional Vascular Changes and Aortic Dilatation in Pediatric Patients With Bicuspid Aortic Valve.

BACKGROUND: Bicuspid aortic valve (BAV) is the most common congenital heart disease, often associated with valve dysfunction, coarctation of the aorta, and ascending aorta dilatation. Aortic dilatation might result from abnormal regional hemodynamics or inherent vascular disease. Vascular function in pediatric BAV remains poorly characterized. METHODS: A cross-sectional study was performed to evaluate vascular function in 142 children with BAV aged 7-18 years compared with healthy control children. Echocardiography was performed to assess aortic dimensions, BAV function, and vascular function (aortic arch pulse wave velocity [PWV]), carotid intima media thickness, and aortic stiffness and distensibility). Carotid-femoral and carotid-radial PWV were assessed using tonometry. Vascular function was compared for 4 patient groups stratified according to aortic dilatation and a history of coarctation of the aorta. Multivariate regression analysis was performed to determine predictors of aortic dilatation. RESULTS: Children with BAV had stiffer and less distensible ascending aortas with higher aortic arch PWV compared with control children. Carotid-femoral and carotid-radial PWV were not increased in patients with BAV, and the vascular assessment of the abdominal aorta was unremarkable. Multivariate regression revealed that aortic arch PWV was the only vascular function parameter that was associated with aortic dilatation. CONCLUSIONS: Children with BAV have differences in vascular function that are confined to their proximal aorta, even in normal functioning BAV. The observed differences in vascular function are likely multifactorial, with contributions from abnormal regional flow and a potential localized primary aortopathy.

Atrial fibrillation following transcatheter atrial septal defect closure: a systematic review and meta-analysis.

OBJECTIVE: The ostium secundum atrial septal defect (ASD) is among the most common congenital cardiac anomalies diagnosed in adulthood. A known complication of transcatheter ASD closure is the development of new-onset atrial fibrillation and flutter (AFi/AFl). These arrhythmias confer an increased risk of postoperative stroke, thrombus formation and systemic emboli. This systematic review examines the burden of de novo AFi/AFl in adults following transcatheter closure and seeks to identify risk factors for AFi/AFl development. METHODS: Studies were identified by a search of MEDLINE, EMBASE and Cochrane databases from inception until 29 April 2020. A meta-analysis of AFi/AFl incidence was performed using a random-effects model. RESULTS: A total of 31 studies met inclusion criteria, comprising 4788 adult patients without a history of AFi/AFl. Twenty-three studies were included in quantitative synthesis and demonstrated an overall incidence rate of 1.82 patients per 100 person-years of follow-up (I2=83%). In studies that enrolled only patients ≥60 years old, the incidence was 5.21 patients per 100 person-years (I2=0%). Studies with follow-up duration ≤2 years reported an incidence of 4.05 per 100 person-years (I2=55%) compared with a rate of 1.19 per 100 person-years (I2=85%) for studies with follow-up duration >2 years. CONCLUSIONS: The incidence of new-onset AFi/AFl is relatively low following transcatheter closure of secundum ASDs. The rate of de novo AFi/AFl, however, was significantly higher in elderly patients. Shorter follow-up time was associated with a higher reported incidence of AFi/AFl.

Predictors of Bicuspid Aortic Valve-Associated Aortopathy in Childhood: A Report From the MIBAVA Consortium.

BACKGROUND: Bicuspid aortic valve (BAV) is the most prevalent congenital heart defect affecting 1% to 2% of the population. It is associated with ascending aorta dilatation. Valve morphology, aortic stenosis (AS), and aortic insufficiency (AI) have been proposed as potential risk factors; however, evaluating their role is difficult, as these factors are inherently related. The aim of this study was to determine whether BAV morphology and dysfunction are independent determinants for ascending aorta dilatation in pediatric patients. METHODS: A multicenter, retrospective, cross-sectional study of pediatric BAV patients followed since 2004 was performed. Imaging data were assessed for BAV morphology, severity of AS and AI, history of coarctation, and aortic dimensions. Associations were determined using multivariable regression analysis. A subset of patients undergoing aortic interventions (balloon dilation or Ross) were assessed longitudinally. RESULTS: Data were obtained from 2122 patients (68% male; median age 10.2 years). Fifty percent of patients had ascending aorta dilatation. Right and noncoronary cusp fusion, increasing AS and AI, and older age were independently associated with ascending aorta dilatation. A history of coarctation was associated with less ascending aorta dilatation. In patients with neither AS nor AI, 37% had ascending aorta dilatation (4% severe). No complications related to aortic dilatation occurred in this cohort. Aortic Z scores were determined, and a Z-score calculator was created for this population. CONCLUSIONS: In this large pediatric cohort of patients with BAV, valve morphology, AS, and AI are independently associated with ascending aorta dilatation, suggesting that hemodynamic factors influence aortopathy. However, even in BAVs with no AS or AI, there is significant ascending aorta dilatation independent of valve morphology. Interventions that led to changes in degree of AI and AS did not seem to influence change in aortic dimensions. The current BAV cohort can be used as a reference group for expected changes in aortic dimensions during childhood.

Management and Outcomes of Childhood Renal Artery Stenosis and Middle Aortic Syndrome.

BACKGROUND: Renal artery stenosis (RAS) in isolation or in conjunction with middle aortic syndrome (MAS) are important vascular causes of childhood hypertension. Few longitudinal studies have assessed the risk of surgical or endovascular intervention, and outcomes by etiology or extent of vascular disease. METHODS: In a retrospective study of 93 children seen over 30 years with RAS and/or MAS, data on vascular involvement (isolated RAS vs. RAS with MAS), etiology (unknown, inflammatory, or genetic), and management were collected. Time to first intervention (endovascular or surgical) was assessed by Cox regression. Mixed-effects analysis examined the longitudinal change in blood pressure after intervention compared to antihypertensive medications alone. RESULTS: Children were 7.0 ± 5.4 years old. Etiology was unknown in 50%, genetic in 26% and inflammatory in 24% of children. Children had isolated RAS (49%) or MAS with or without RAS (51%). Overall, 70% were managed with surgical or endovascular intervention. After adjusting for age, sex, and systolic blood pressure, children with unknown etiology had a higher risk of intervention compared to those with genetic and inflammatory diseases (hazard ratio 3.1, 95% confidence interval [CI] 1.7, 5.6). Children with RAS and MAS were less likely to receive intervention (hazard ratio 0.4, 95% CI 0.2, 0.8) than isolated RAS. Over a median follow-up of 2 years, 65% remained hypertensive. The longitudinal changes in systolic blood pressure did not differ by etiology, or between interventional and medical management. CONCLUSIONS: Hypertension persists despite endovascular or surgical management of childhood RAS and MAS highlighting the importance of close monitoring and ongoing medical management.

Cardiovascular Structure and Function in Children With Middle Aortic Syndrome and Renal Artery Stenosis.

Middle aortic syndrome (MAS) is a narrowing of the abdominal aorta, often in conjunction with renal artery stenosis (RAS). Structure and function of the cardiovascular system are not well understood. In a prospective cross-sectional study, 35 children with MAS or RAS or both (MAS/RAS) were compared with 140 age-, sex-, and body surface area-matched healthy children. Vascular assessment included carotid intima-media thickness and carotid distensibility using B-mode ultrasound and central and peripheral pulse wave velocities using applanation tonometry. Left ventricular structure and function were assessed by 2-dimensional and speckle-tracking echocardiography. Children with MAS or RAS were 12.5±3.0 years old at enrollment, and 50% were men. Carotid intima-media thickness (0.54±0.10 versus 0.44±0.05 mm; P<0.001) and central pulse wave velocities (5.58±1.83 versus 5.00±0.90 m/s; P=0.01) were significantly higher in children with disease compared with healthy children; however, after adjustment for systolic blood pressure z score, only carotid intima-media thickness remained significantly higher in the MAS/RAS group compared with the controls (ß=0.07 [0.03, 0.10]). Peripheral pulse wave velocities and carotid distensibility were normal. Children with disease had significantly increased left ventricular mass and changes in diastolic function (lower E/a ratio and lower e' velocities). Systolic parameters, including ejection fraction, global longitudinal and circumferential strain, were similar to controls. Our findings demonstrate that children with MAS or RAS have evidence of carotid and left ventricular remodeling, without peripheral arterial involvement, which suggests a localized disease process. Left ventricular systolic function is preserved; however, subtle changes in diastolic function are observed. Carotid vessel changes are consistent with a 5- to 10-year aging, which underscores the importance of blood pressure control.

Longitudinal assessment of myocardial function in childhood chronic kidney disease, during dialysis, and following kidney transplantation.

BACKGROUND: Childhood chronic kidney disease (CKD) and dialysis are associated with increased long-term cardiovascular risk. We examined subclinical alterations in myocardial mechanics longitudinally in children with CKD, during dialysis, and following renal transplantation. METHODS: Forty-eight children with CKD (stage III or higher) who received kidney transplants from 2008 to 2014 were included in a retrospective study and compared to 192 age- and sex-matched healthy children. Measurements of cardiac systolic and diastolic function were performed, and global longitudinal strain (GLS) and circumferential strain (GCS) were measured by speckle-tracking echocardiography at CKD, during dialysis, and 1 year following kidney transplantation. Mixed-effects modeling examined changes in GLS and GCS over different disease stages. RESULTS: Children with CKD had a mean age of 10 ± 5 years and 67% were male. Eighteen children received preemptive transplantation. Children with CKD had increased left ventricular mass, lower GLS, and impaired diastolic function (lower E/A ratio and E' velocities) than healthy children. Changes in left ventricular diastolic parameters persisted during dialysis and after renal transplantation. Dialysis was associated with reduced GLS compared to CKD (ß = 1.6, 95% confidence interval 0.2-3.0); however, this was not significant after adjustment for systolic blood pressure and CKD duration. Post-transplantation GLS levels were similar to those at CKD assessment. GCS was unchanged during dialysis but significantly improved following transplantation. CONCLUSIONS: There are differences in diastolic parameters in childhood CKD that persist during dialysis and after transplantation. Systolic parameters are preserved, with significant improvement in systolic myocardial deformation following transplantation. The impact of persistent diastolic changes on long-term outcomes requires further investigation.

Disease Beyond the Arch: A Systematic Review of Middle Aortic Syndrome in Childhood.

BACKGROUND: Middle aortic syndrome (MAS) is a rare clinical entity in childhood, characterized by a severe narrowing of the distal thoracic and/or abdominal aorta, and associated with significant morbidity and mortality. MAS remains a relatively poorly defined disease. This paper systematically reviews the current knowledge on MAS with respect to etiology, clinical impact, and therapeutic options. METHODS: A systematic search of 3 databases (Embase, MEDLINE, and Cochrane Central Register of Controlled Trials) yielded 1,252 abstracts that were screened based on eligibility criteria resulting in 184 full-text articles with 630 reported cases of childhood MAS. Data extracted included patient characteristics, clinical presentation, vascular phenotype, management, and outcomes. RESULTS: Most cases of MAS are idiopathic (64%), 15% are associated with Mendelian disorders, and 17% are related to inflammatory diseases. Extra-aortic involvement including renal (70%), superior mesenteric (30%), and celiac (22%) arteries is common, especially among those with associated Mendelian disorders. Inferior mesenteric artery involvement is almost never reported. The majority of cases (72%) undergo endovascular or surgical management with residual hypertension reported in 34% of cases, requiring medication or reintervention. Clinical manifestations and extent of extra-aortic involvement are lacking. CONCLUSIONS: MAS presents with significant involvement of visceral arteries with over two thirds of cases having renal artery stenosis, and one third with superior mesenteric artery stenosis. The extent of disease is worse among those with genetic and inflammatory conditions. Further studies are needed to better understand etiology, long-term effectiveness of treatment, and to determine the optimal management of this potentially devastating condition.