Aortic stiffening and its impact on left atrial volumes and function in patients after successful coarctation repair: a multiparametric cardiovascular magnetic resonance study.

BACKGROUND: The increased cardiovascular morbidity of adults with late repair of aortic coarctation (CoA) has been well documented. In contrast, successful CoA repair in early childhood has a generally good prognosis, though adverse vascular and ventricular characteristics may be abnormal, which could increase long-term risk. This study sought to perform a comprehensive analysis of aortic elasticity and left ventricular (LV) function in patients with aortic coarctation (CoA) using cardiovascular magnetic resonance (CMR). In a subgroup of patients, we assessed structure and function of the common carotid arteries to probe for signs of systemic vascular remodeling. METHODS: Fifty-one patients (median age 17.3 years), 13.9 ± 7.5 years after CoA repair, and 54 controls (median age 19.8 years) underwent CMR. We determined distensibility and pulse wave velocity (PWV) at different aortic locations. In a subgroup, common carotid artery distensibility, PWV, wall thickness and wall area were measured. LV ejection fraction (EF), volumes, and mass were measured from short axis views. Left atrial (LA) volumes and functional parameters (LAEFPassive, LAEFContractile, LAEFReservoir) were assessed from axial cine images. RESULTS: In patients distensibility of the whole thoracic aorta was reduced (p < 0.05) while PWV was only significantly higher in the aortic arch (p < 0.01). Distensibility of the descending aorta at the level of the pulmonary arteries and PWV in the descending aorta, both correlated negatively with age at CoA repair. LA volume before atrial contraction and minimal LA volume were higher in patients (p < 0.05). LAEFPassive and LAEFReservoir were reduced (p < 0.05), and LAEFReservoir correlated negatively with aortic arch PWV (p < 0.05). LVEF, volumes and mass were not different from controls. Carotid wall thickness and PWV were higher in patients compared to controls (p < 0.05). CONCLUSIONS: Patients after CoA repair have impaired bioelastic properties of the thoracic aorta with impact on LV diastolic function. Reduced descending aortic elasticity is associated with older age at time of CoA repair. The remodeling of the common carotid artery in our sub-study suggests systemic vessel wall changes.

Publisher Correction: Heart beat but not respiration is the main driving force of the systemic venous return in the Fontan circulation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Heart beat but not respiration is the main driving force of the systemic venous return in the Fontan circulation.

The Fontan procedure provides relief from cyanosis in patients with univentricular hearts. A major clinical unmet need is to understand whether the venous flow patterns of the Fontan circulation lead to the development of congestive hepatopathy and other life-threatening complications. Currently, there is no consensus on whether heart beat or respiration is the main driving force of venous return and which one affects the periodic flow changes for the most (i. e., pulsatility). The present study, for the first time, quantified respiratory and cardiac components of the venous flow in the inferior vena cava (IVC) of 14 Fontan patients and 11 normal controls using a novel approach ("physio-matrix"). We found that in contrast to the normal controls, respiration in Fontan patients had a significant effect on venous flow pulsatility, and the ratio of respiration-dependent to the cardiac-dependent pulsatility was positively associated with the retrograde flow. Nevertheless, the main driving force of net IVC flow was the heart beat and not respiration. The separate analysis of the effects of respiration and heart beat provides new insights into the abnormal venous return patterns that may be responsible for adverse effects on liver and bowel of the patients with Fontan circulation.

Restrictive enlargement of the pulmonary annulus at repair of tetralogy of Fallot: a comparative 10-year follow-up study.

OBJECTIVES: Since 1996, our centre performs restrictive enlargement of the pulmonary annulus at surgical repair of tetralogy of Fallot. A transannular patch is only used if the z-score of the pulmonary annulus is smaller than -2. We sought to determine whether this strategy reduces pulmonary insufficiency (PI) and reoperation rate compared to a nationwide contemporary cohort that has not been operated using a uniform strategy. METHODS: Eighty-seven tetralogy of Fallot patients were included in the study (Group 1). One hundred sixty-seven tetralogy of Fallot patients from the Competence Network for Congenital Heart Disease served as controls (Group 2). Clinical, echocardiographic, electrocardiogram, cardiovascular magnetic resonance and outcome data were analysed. RESULTS: Follow-up time since repair was not different between groups [12.9 (7.8-18.8) vs 13.1 (5.2-16.9) years, P = 0.96] while transannular patch rate was significantly lower in Group 1 (32.2% vs 64.7%, P < 0.001). Ten-year freedom from reoperation for PI was significantly higher in our cohort (98% vs 92%, P = 0.01). Multivariable analysis identified restrictive enlargement as the only predictor for no need of reoperation [hazard ratio 0.4 (95% confidence interval 0.24-0.84), P < 0.01]. In Group 1, cardiovascular magnetic resonance-derived volumes were smaller (indexed end-diastolic volume: 103 ± 24 vs 123 ± 31 ml/m2, P < 0.001; indexed end-systolic volume: 53 ± 19 vs 59 ± 20 ml/m2, P = 0.04) and regurgitation fraction was lower (21 ± 14 vs 31 ± 17%, P < 0.001). CONCLUSIONS: Restrictive enlargement of the pulmonary annulus reduces PI and limits the amount of right ventricular dilatation at intermediate-term follow-up. The need for reoperation to alleviate PI is significantly lower compared to a contemporary cohort. Restrictive enlargement strategy has a stronger influence on freedom from reoperation than the use of a transannular patch. CLINICAL TRIAL REGISTRATION: WHO Main ID: DRKS00010087. URL: http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00010087.

Is the Lecompte technique the last word on transposition of the great arteries repair for all patients? A magnetic resonance imaging study including a spiral technique two decades postoperatively.

OBJECTIVES: To compare the Lecompte technique and the spiral anastomosis (complete anatomic correction) two decades after arterial switch operation (ASO). METHODS: Nine patients after primary ASO with Lecompte and 6 selected patients after spiral anastomosis were evaluated 20.8 ± 2.1 years after ASO versus matched controls. Blood flow dynamics and flow profiles (e.g. vorticity, helicity) in the great arteries were quantified from time-resolved 3D magnetic resonance imaging (MRI) phase contrast flow measurements (4D flow MR) in addition to a comprehensive anatomical and functional cardiovascular MRI analysis. RESULTS: Compared with spiral reconstruction, patients with Lecompte showed more vortex formation, supranatural helical blood flow (relative helicity in aorta: 0.036 vs 0.089; P < 0.01), a reduced indexed cross-sectional area of the left pulmonary artery (155 vs 85 mm²/m²; P < 0.001) and more semilunar valve dysfunctions (n = 5 vs 1). There was no difference in elastic aortic wall properties, ventricular function, myocardial perfusion and myocardial fibrosis between the two groups. Cross-sectional area of the aortic sinus was larger in patients than in controls (669 vs 411 mm²/m²; P < 0.01). In the spiral group, the pulmonary root was rotated after ASO more towards the normal left position (P < 0.01). CONCLUSIONS: In this study, selected patients with spiral anastomoses showed, two decades after ASO, better physiologically adapted blood flow dynamics, and attained a closer to normal anatomical position of their great arteries, as well as less valve dysfunction. Considering the limitations related to the small number of patients and the novel MRI imaging techniques, these data may provoke reconsidering the optimal surgical approaches to transposition of the great arteries repair.

Frequent Dilatation of the Descending Aorta in Children With Hypoplastic Left Heart Syndrome Relates to Decreased Aortic Arch Elasticity.

BACKGROUND: Patients with hypoplastic left heart syndrome after a Norwood operation show dilatation and reduced distensibility of the reconstructed proximal aorta. Cardiac magnetic resonance imaging (CMR) and angiographic examinations indicate that the native descending aorta (DAo) is also dilated, but this has not been studied in detail. METHODS AND RESULTS: Seventy-nine children with hypoplastic left heart syndrome in Fontan circulation (aged 6.3±3.2 years) and 18 control participants (aged 6.8±2.4 years) underwent 3.0-tesla CMR. Gradient-echo cine and phase-contrast imaging was applied to measure cross-sectional areas (CSAs), distensibility, pulse wave velocity, and the incremental elastic modulus of the thoracic aorta. CSA of the DAo in patients was also compared with published percentiles for aortic CSA. Patients had significantly larger CSA of the DAo at the level of pulmonary artery bifurcation (229.1±97.2 versus 175.7±24.3 mm/m(2), P=0.04) and the diaphragm (196.2±66.0 versus 142.6±16.7 mm/m(2), P<0.01). In 41 patients (52%), CSA of the DAo was >95th percentile level for control participants, and the incremental elastic modulus of the aortic arch and the DAo was higher than in patients with normal CSAs (arch: 90.1±64.3 versus 45.6±38.9 m/s; DAo: 86.3±53.7 versus 47.1±47.6 m/s; P<0.01). Incremental elastic modulus of the aortic arch and the DAo correlated with the CSA of the DAo (arch: r=0.5; DAo: r=0.49; P<0.01). CONCLUSIONS: Children with hypoplastic left heart syndrome frequently show dilatation of their DAo associated with increased stiffness of the aortic arch. Higher aortic impedance increases the afterload of the systemic circulation and likely contributes to the burden of the systemic right ventricle.

A new simple method to estimate pulmonary regurgitation by echocardiography in operated fallot: comparison with magnetic resonance imaging and performance test evaluation.

BACKGROUND: The aim of this study was to assess a novel transthoracic echocardiographic method to estimate the severity of pulmonary regurgitation (PR) in patients with surgically repaired tetralogy of Fallot. METHOD: In 63 patients with operated tetralogy of Fallot, PR was evaluated by vena contracta width, jet deceleration, PR index, pressure half-time, and a new index, referred to as Pulmonary Regurgitation Index by M-mode echocardiography (PRIME), which is the systolic-to-diastolic variation in right pulmonary artery diameter. The results were matched to PR fraction (PRF) assessed by cardiovascular magnetic resonance imaging. PRIME cutoff values for selecting patients with mild, moderate, and severe PR were identified by maximizing PRIME sensitivity and specificity. Nonlinear regression by 3-parameter logistic function was used to estimate PRF by PRIME. RESULTS: The sensitivity and specificity of PRIME were high for all diagnostic targets: PRF > or =15% versus <15%, PRF > or =25% versus <25%, and PRF >40% versus < or =40%. The nonlinear regression model showed a good correlation between PRF and PRIME (R(2) = 0.95). CONCLUSION: PRIME is a simple and accurate method to estimate PR by transthoracic echocardiography in patients with operated tetralogy of Fallot.