Dataset Information

Quantitative collagen assessment in right ventricular myectomies from patients with tetralogy of Fallot.

ABSTRACT:

Aims

Patients with tetralogy of Fallot (TOF) are often affected by right ventricular fibrosis, which has been associated with arrhythmias. This study aimed to assess fibrosis distribution in right ventricular outflow tract (RVOT) myocardium of TOF patients to evaluate the utility of single histology-section analyses, and to explore the possibility of fibrosis quantification in unlabelled tissue by second harmonic generation imaging (SHGI) as an alternative to conventional histology-based assays.

Methods and results

We quantified fibrosis in 11 TOF RVOT samples, using a tailor-made automated image analysis method on Picrosirius red-stained sections. In a subset of samples, histology- and SHGI-based fibrosis quantification approaches were compared. Fibrosis distribution was highly heterogeneous, with significant and comparable variability between and within samples. We found that, on average, 67.8 mm2 of 10?µm thick, histologically processed tissue per patient had to be analysed for accurate fibrosis quantification. SHGI provided data faster and on live tissue, additionally enabling quantification of collagen anisotropy.

Conclusion

Given the high intra-individual heterogeneity, fibrosis quantification should not be conducted on single sections of TOF RVOT myectomies. We provide an analysis algorithm for fibrosis quantification in histological images, which enables the required extended volume analyses in these patients.

SUBMITTER: Wulfers EM

PROVIDER: S-EPMC7943371 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Publications

Quantitative collagen assessment in right ventricular myectomies from patients with tetralogy of Fallot.

Wülfers Eike M EM Greiner Joachim J Giese Max M Madl Josef J Kroll Johannes J Stiller Brigitte B Kohl Peter P Rog-Zielinska Eva A EA Fürniss Hannah E HE

Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology 20210301 23 Suppl 1

<h4>Aims</h4>Patients with tetralogy of Fallot (TOF) are often affected by right ventricular fibrosis, which has been associated with arrhythmias. This study aimed to assess fibrosis distribution in right ventricular outflow tract (RVOT) myocardium of TOF patients to evaluate the utility of single histology-section analyses, and to explore the possibility of fibrosis quantification in unlabelled tissue by second harmonic generation imaging (SHGI) as an alternative to conventional histology-based ...[more]

PMID: 33404047

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Project description:BackgroundPatients with repaired tetralogy of Fallot (rTOF) experience long-term chronic pulmonary valve regurgitation resulting in right ventricular (RV) dilatation. According to current guidelines, the evaluation of patients with rTOF for RV dilatation should be based on cardiac magnetic resonance (CMR). However, for many asymptomatic patients, routine CMR is not practical. Our study aims to identify screening methods for CMR based on echocardiographic data, with the goal of establishing a more practical and cheap method of screening for severity of RV dilatation in patients with asymptomatic rTOF.MethodsThirty two rTOF patients (mean age, 21(10.5) y, 21 males) with moderate to severe pulmonary regurgitation (PR) were prospectively recruited. Each patient received CMR and echocardiogram examination within 1 month prior to operation and collected clinical data, and then received echocardiogram examination at discharge and 3-6 months post-surgery.ResultsRV moderate-severe dilatation was defined as right ventricular end-diastolic volume index (RVEDVI) ≥ 160 ml/m2 or right ventricular end-systolic volume index (RVESVI) ≥ 80 ml/m2 in 15 of 32 patients (RVEDVI, 202.15[171.51, 252.56] ml/m2, RVESVI, 111.99 [96.28, 171.74] ml/m2). The other 17 (RVESDI, 130.19 [117.91, 139.35] ml/m2, RVESVI = 67.91 [63.35, 73.11] ml/m2) were defined as right ventricle mild dilatation, i.e., RVEDVI < 160 ml/m2 and RVESVI < 80 ml/m2, and the two parameters were higher than normal values. Compared with the RV mild dilatation group, patients of RV moderate-severe dilatation have worse cardiac function before surgery (right ventricular ejection fraction, 38.92(9.19) % versus 48.31(5.53) %, p < 0.001; Left ventricular ejection fraction, 59.80(10.26) versus 66.41(4.15), p = 0.021). Patients with RV moderate-severe dilatation faced longer operation time and more blood transfusion during operation (operation time, 271.53(08.33) min versus 170.53(72.36) min, p < 0.01; Intraoperative blood transfusion, 200(175) ml versus 100(50) ml, p = 0.001). Postoperative RV moderate-severe dilatation patients have poor short-term prognosis, which was reflected in a longer postoperative hospital stay (6.59 [2.12] days versus 9.80 [5.10] days, p = 0.024) and a higher incidence of hypohepatia (0[0] % versus 4[26.7] %, p = 0.023). Patients with RV dilatation score > 2.35 were diagnosed with RV moderate-severe dilatation (AUC = 0,882; Sensitivity = 94.1%; Specificity = 77.3%).ConclusionsRV moderate-severe dilatation is associated with worse preoperative cardiac function and short-term prognosis after PVR in rTOF patients with moderate to severe PR. The RV dilatation score is an effective screening method. When RV dilatation score > 2.35, the patient is indicated for further CMR examination and treatment.

Project description:Background and purposeElectromechanical dyssynchrony, manifested by right bundle branch block and regional wall mechanical dysfunction, contributes to inefficient RV function in repaired Tetralogy of Fallot (ToF). This study aims to evaluate the synchronicity of multiple RV walls using two-dimensional multi-plane echocardiography (2D-MPE) in order to augment current understanding of the mechanisms behind RV dyssynchrony.MethodsSixty-nine adult ToF patients [aged 33 (23-45) years; 61% male] and twenty-five matched healthy controls underwent deformational analysis of the RV lateral, anterior, inferior and septal walls following 2D-MPE acquisitions. RV synchronicity was assessed by the intra-RV deformation delay between each basal RV wall and mid-septal segment in addition to mechanical dispersion calculated across four, six and eight segments (MD).ResultsAll RV wall-septum delays plus MD-4 and MD-6 indices were significantly greater in ToF patients compared to healthy controls (p < 0.001-0.03). In ToF patients, the lateral and anterior RV walls were last to reach peak deformation and anterior wall longitudinal strain was lower (p = 0.001). Post systolic shortening of at least one RV wall segment was identified in 19 (28%) ToF patients. Despite similar ECG characteristics, lateral and anterior wall-septum delays were significantly longer in patients with greater degrees of dyssynchrony (73 [37-108]ms vs. 37 [0-63]ms, p = 0.006; 91 [52-116]ms vs. 41 [1-69]ms, p = 0.013), although RV ejection fraction (RVEF) was not significantly lower. MD-4 and MD-8 indices displayed moderate negative associations with RVEF, strengthened by inclusion of lateral wall longitudinal strain (r = 0.64/0.65; p ≤0.01).ConclusionRV dyssynchrony in ToF is characterised by electromechanical delays between the lateral, anterior and septal walls, with anterior wall dysfunction likely associated with surgical repair of the RV outflow tract. Prospectively, 2D-MPE may have an emerging role evaluating RV mechanical response to electrical resynchronisation therapy.

Project description:BackgroundRelationships between right ventricular (RV) and left ventricular (LV) shape and function may be useful in determining optimal timing for pulmonary valve replacement in patients with repaired tetralogy of Fallot (rTOF). However, these are multivariate and difficult to quantify. We aimed to quantify variations in biventricular shape associated with pulmonary regurgitant volume (PRV) in rTOF using a biventricular atlas.MethodsIn this cross-sectional retrospective study, a biventricular shape model was customized to cardiovascular magnetic resonance (CMR) images from 88 rTOF patients (median age 16, inter-quartile range 11.8-24.3 years). Morphometric scores quantifying biventricular shape at end-diastole and end-systole were computed using principal component analysis. Multivariate linear regression was used to quantify biventricular shape associations with PRV, corrected for age, sex, height, and weight. Regional associations were confirmed by univariate correlations with distances and angles computed from the models, as well as global systolic strains computed from changes in arc length from end-diastole to end-systole.ResultsPRV was significantly associated with 5 biventricular morphometric scores, independent of covariates, and accounted for 12.3% of total shape variation (p < 0.05). Increasing PRV was associated with RV dilation and basal bulging, in conjunction with decreased LV septal-lateral dimension (LV flattening) and systolic septal motion towards the RV (all p < 0.05). Increased global RV radial, longitudinal, circumferential and LV radial systolic strains were significantly associated with increased PRV (all p < 0.05).ConclusionA biventricular atlas of rTOF patients quantified multivariate relationships between left-right ventricular morphometry and wall motion with pulmonary regurgitation. Regional RV dilation, LV reduction, LV septal-lateral flattening and increased RV strain were all associated with increased pulmonary regurgitant volume. Morphometric scores provide simple metrics linking mechanisms for structural and functional alteration with important clinical indices.

Project description:Background The relative impact of right ventricular ( RV ) electromechanical dyssynchrony versus pulmonary regurgitation ( PR ) on exercise capacity and RV function after tetralogy of Fallot repair is unknown. We aimed to delineate the relative effects of these factors on RV function and exercise capacity. Methods and Results We retrospectively analyzed 81 children with tetralogy of Fallot repair using multivariable regression. Predictor parameters were electrocardiographic QRS duration reflecting electromechanical dyssynchrony and PR severity by cardiac magnetic resonance. The outcome parameters were exercise capacity (percentage predicted peak oxygen consumption) and cardiac magnetic resonance ejection fraction (RV ejection fraction). To understand the relative effects of RV dyssynchrony versus PR on exercise capacity and RV function, virtual patient simulations were performed using a closed-loop cardiovascular system model (CircAdapt), covering a wide spectrum of disease severity. Eighty-one patients with tetralogy of Fallot repair (median [interquartile range { IQR} ] age, 14.48 [11.55-15.91] years) were analyzed. All had prolonged QRS duration (median [IQR], 144 [123-152] ms), at least moderate PR (median [IQR], 40% [29%-48%]), reduced exercise capacity (median [IQR], 79% [68%-92%] predicted peak oxygen consumption), and reduced RV ejection fraction (median [IQR], 48% [44%-52%]). Longer QRS duration, more than PR , was associated with lower oxygen consumption and lower RV ejection fraction. In a multivariable regression analysis, oxygen consumption decreased with both increasing QRS duration and PR severity. CircAdapt modeling showed that RV dyssynchrony exerts a stronger limiting effect on exercise capacity and on RV ejection fraction than does PR , regardless of contractile function. Conclusions In both patient data and computer simulations, RV dyssynchrony, more than PR , appears to be associated with reduced exercise capacity and RV systolic dysfunction in patients after TOF repair.

Dataset Information

Quantitative collagen assessment in right ventricular myectomies from patients with tetralogy of Fallot.

Aims

Methods and results

Conclusion

Publications

Quantitative collagen assessment in right ventricular myectomies from patients with tetralogy of Fallot.

Similar Datasets

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