Unchanged right ventricular strain in repaired tetralogy of Fallot after pulmonary valve replacement with radial long-axis cine magnetic resonance images

Atrial and ventricular strain changes after transcatheter pulmonary valve replacement in patients with repaired tetralogy of Fallot: a feature tracking cardiac MRI study

PURPOSE

In patients with repaired tetralogy of Fallot, transcatheter or surgical pulmonary valve replacement is recommended. However, it is not clear whether pulmonary valve replacement preserves systolic and diastolic functions of both ventricles. The aim of the study is to investigate the impact of transcatheter pulmonary valve replacement on atrial and ventricular myocardial strain changes by feature-tracking cardiac magnetic resonance imaging.

MATERIALS AND METHODS

Cardiac magnetic resonance imaging of 18 patients (median age 14.5 years) with repaired tetralogy of Fallot before and after transcatheter pulmonary valve replacement were retrospectively analyzed. Feature tracking strain for both left and right atria and ventricles was performed. Cardiac magnetic resonance imaging parameters (volume and function) and strain characteristics (atria and ventricles) were compared before and after transcatheter pulmonary valve replacement. The Wilcoxon rank-sum and Spearman correlation test was used.

RESULTS

After pulmonary valve replacement, right ventricular end-diastolic volume, end-systolic volume, and stroke volume decreased, whereas left and right ventricular ejection fractions remained unchanged. Reservoir, conduit and pump strain measurements improved for both left (P = 0.003, P = 0.001, and P = 0.006) and right atria (P = 0.013, P = 0.004, and P = 0.015). Global left ventricular circumferential, longitudinal, and radial strains improved (P = 0.001, P = 0.043, and P = 0.002, respectively). Right ventricle global circumferential strain significantly improved with no significant change in the longitudinal and radial strains (P = 0.007, P = 0.068, and P = 0.055, respectively).

CONCLUSION

Transcatheter pulmonary valve replacement significantly enhances atrial and ventricular strain parameters, indicating a positive impact on overall myocardial function. Feature-tracking cardiac magnetic resonance imaging may offer a comprehensive, non-invasive evaluation of myocardial strain changes in patients with repaired tetralogy of Fallot after pulmonary valve replacement, which leads to improvement of indications and outcomes.

Evaluating the Sapien® XT Valve in Native Right Ventricular Outflow Tracts After Tetralogy of Fallot Repair: Mid- and Long-Term Results

Although the long-term outcomes of the surgical grafts are well defined and reported, the data regarding the mid-and long-term results of the balloon-expandable percutaneous valves in the native right ventricular outflow tract (RVOT) is limited. We retrospectively evaluated 42 patients who underwent PPVI (Sapien® XT valve) to native RVOT due to severe pulmonary regurgitation (PR) and/or moderate to severe pulmonary stenosis (PS) between August 2015 and November 2020. The median patient age at the time of PPVI was 13.4 years (6.1-36.5 years). The median body weight of the patients was 42 kg (15-110 kg). The rate of patients who were followed up without the need for percutaneous or surgical intervention was 97.4% at the end of year 1, 89.3% at the end of year 3, and 85.8% at the end of year 5. At the end of year 6, the proportion of patients requiring no procedure remained constant, with year 5 at 85.8%, but decreased to 70.2% at the end of year 7. Although the early results are very encouraging, it is seen that PPVI in patients with RVOT in the long term brings some problems. The most important of these is tricuspid valve problems, which were not considered before the procedure. Patients requiring reintervention due to pulmonary regurgitation show similar characteristics to surgical valves' long-term results.

Myocardial strain analysis by cardiac magnetic resonance associated with arrhythmias in repaired tetralogy of Fallot patients

BACKGROUND

Evaluating myocardial function using cardiac magnetic resonance (CMR) feature tracking provides a comprehensive cardiac assessment, particularly a detailed evaluation for patients with repaired tetralogy of Fallot (rTOF). This study aimed to identify factors associated with arrhythmias in rTOF patients utilizing conventional CMR techniques, including myocardial strain measurements.

METHODS

This single-center, retrospective study included 245 rTOF patients who underwent CMR between 2017 and 2023. Patients were stratified based on the presence or absence of arrhythmias during follow-up. The biventricular strain was assessed using CMR-derived feature tracking. Demographic, clinical, and imaging data were collected, and statistical analyses were performed to identify factors associated with arrhythmic events.

RESULTS

The median age at surgery was 5.6 years (range 1-44 years), with the median age at CMR was 27.5 years (range 15-69 years). Over the follow-up period, 25 patients (10.2%) experienced atrial or ventricular arrhythmias. Univariate analysis revealed significant associations between arrhythmic events and older age at surgery and CMR, lower functional class, larger heart size on chest radiograph, and prolonged QRS duration (QRSd). Additionally, arrhythmias were associated with increased right ventricular (RV) volume, reduced RV and left ventricular (LV) ejection fraction (EF), and impaired strain values. Multivariate binary logistic regression, adjusting for age at surgery, NYHA class, QRSd, and cardiothoracic ratio, identified that a lower RV EF (adjusted odds ratio [aOR] 6.97), RV global radial strain (GRS) (aOR 6.68), RV global circumferential strain (GCS) (aOR 6.36), RV global longitudinal strain (GLS) (aOR 3.14), and LV GRS (aOR 3.02) were all significantly associated with arrhythmias.

CONCLUSION

This study highlights the significant contribution of CMR-derived myocardial strain measurements in predicting arrhythmic events in patients with rTOF. In addition to conventional RV EF, strain metrics-particularly those of the right ventricle- emerged as strong, independent predictors of arrhythmias, offering valuable prognostic information for clinical management in this patient population. These findings underscore the importance of myocardial strain analysis as a complementary tool to conventional imaging in evaluating arrhythmic risk in rTOF patients.

CLINICAL TRIAL NUMBER

Not applicable.

Management of Pediatric Congenital Heart Disease

We are pleased to present a Special Issue dedicated to pediatric cardiology [...].

Cardiac Magnetic Resonance Imaging in the Evaluation of Functional Impairments in the Right Heart

Cardiac magnetic resonance (cMRI) imaging has recently become essential in cardiology. cMRI is widely recognized as the most reliable imaging technique for assessing the size and performance of the right ventricle. It allows for objective and functional cardiac tissue evaluations. Early in disease progression, cardiac structure and activity decrease subclinically. Late-phase clinically visible signs have been associated with less favourable outcomes. Subclinical alterations ought to be recognized for rapid evaluations and accurate treatment. An increasing amount of evidence supports cMRI deformation parameter quantification. Strain imaging enables cardiologists to assess heart function beyond traditional measurements. Prognostic information for cardiovascular disease patients is obtained through the right ventricle (RV) strain, including information primarily about the left ventricle (LV). Right atrial (RA) function evaluations using RA strain have been promising in recent studies. Therefore, this narrative review aims to present an overview of the data that are currently available for assessing right myocardial strain and biomechanics using cMRI.

Impact of pulmonary stenosis on right ventricular global longitudinal strain in repaired tetralogy of Fallot patients post transcatheter pulmonary valve replacement

BACKGROUND

Mixed pulmonary disease with pulmonary regurgitation (PR) and stenosis (PS) in repaired tetralogy of Fallot (rTOF) can negatively impact ventricular health. Myocardial strain has been shown to be more sensitive at detecting occult ventricular dysfunction compared to right ventricular ejection fraction (RV EF). We hypothesize that rTOF patients with predominant PS will have lower RV global longitudinal strain (RV GLS) prior to and post-transcatheter pulmonary valve replacement (TPVR).

METHODS

A retrospective cohort of rTOF patients who underwent cardiac magnetic resonance (CMR) and cardiac catheterization for right ventricular pressure (RVSP) measurement were analyzed at three time points: before valve implantation, at discharge and within 18 months post-TPVR. Patients were dichotomized into three groups based on RVSP: 0%-49%, 50%-74%, and >75%. RV GLS and left ventricular (LV) GLS by speckle tracking echocardiography (STE) were obtained from the apical 4-chamber using TomTec software (TOMTEC IS, Germany).

RESULTS

Forty-eight patients were included. Every 14.3% increase in preimplantation RVSP above 28% was associated with an absolute magnitude 1% lower RV GLS (p = .001). Preimplantation RVSP when 75% or higher had 3.36% worse RV GLS than the lowest bin (p = .014). Overall, average RV strain magnitude was higher when preimplantation RVSP was less than 50% and had greater improvement over the three time points. Higher post implantation RVSP correlated with lower strain magnitude.

CONCLUSION

Patients with significant PS (>50%) may benefit from earlier PVR and not depend solely on RV size and EF. Myocardial strain may be a more sensitive marker of function; however, larger, prospective studies are needed.

Acute Changes in Right Ventricular Function in Pediatric Patients with Pulmonary Valve Stenosis Undergoing Percutaneous Valvuloplasty: A Speckle-Tracking Study

INTRODUCTION

Pulmonary valve stenosis determines multiple effects on the right ventricular dimension and function. Percutaneous balloon valvuloplasty is the treatment of choice in severe pulmonary valve stenosis in patients of all ages. However, little is known regarding right ventricular function immediate changes after percutaneous balloon dilation. Pediatric patients with isolated pulmonary valve stenosis represent a pure clinical model of chronic RV pressure overload not affected by other confounders or comorbidities.

AIM OF THE STUDY

This study seeks to explore right ventricle (RV) mechanics in pediatric patients early after percutaneous balloon pulmonary valvuloplasty (BPV) for valvar pulmonary stenosis (PS).

MATERIALS AND METHODS

Forty-three pediatric patients (19 males), mean age 3.2 ± 4.9 years old, with severe pulmonary valve stenosis and indication for percutaneous balloon valvuloplasty were recruited. All patients underwent standard transthoracic echocardiography (TTE), and speckle-tracking echocardiography (STE) with an analysis of right ventricle free-wall longitudinal strain (RVFWLS) one day before and one day after the procedure. For each patient, we collected invasive parameters during the interventional procedure before and after BPV.

RESULTS

After the procedure, there was an immediate significant reduction in both peak-to-peak transpulmonary gradient (peak-to-peak PG) and ratio between the right ventricle and aortic systolic pressure (RV/AoP) with a drop of ∆29.3 ± 14.67 mmHg and ∆0.43 ± 0.03, respectively. Post-procedural echocardiography showed peak and mean transvalvar pressure gradient drop (∆50 ± 32.23 and ∆31 ± 17.97, respectively). The degree of pulmonary valve regurgitation was mild in 8% of patients before the procedure, affecting 29% of our patients post-BPV (p = 0.007). The analysis of right ventricular mechanics showed a significant improvement of fractional area change (FAC) immediately after BPV (40.11% vs. 44.42%, p = 0.01). On the other hand, right ventricular longitudinal systolic function parameters, TAPSE and global RVFWLS, did not improve significantly after intervention. The segmental analysis of the RVFWLS showed a significant regional increase in the myocardial deformation of the apical segments.

CONCLUSIONS

Percutaneous BPV represents an efficient and safe procedure to relieve severe pulmonary valve stenosis. The analysis of the right ventricular function on echocardiography demonstrated an immediate global systolic function improvement, while longitudinal systolic function was persistently impaired 24 h after intervention, possibly due to the necessity of a longer recovery time.

Impact of pulmonary valve replacement on left and right ventricular function using strain analysis, in children with repaired tetralogy of Fallot

BACKGROUND

In repaired Tetralogy of Fallot (rTOF), pulmonary regurgitation and resulting right ventricular (RV) and left ventricular (LV) dysfunction are associated with adverse clinical outcomes. We performed an echocardiographic assessment of LV and RV function using Global Longitudinal Strain (GLS) and conventional echo method prior to and following Pulmonary Valvular Replacement (PVR) to help inform proper timing of operation.

RESULTS

A total of 30 rTOF patients (12.17 ± 2.5 years, 70% male) were included. Regarding to LV function, the study revealed a significant reverse correlation between LV GLS (absolute value) and early (mean = 10.4 days) and late (mean = 7.4 months) postop LVEF. Paired T-Test showed significant difference between GLS of LV and RV before and late after operation (op), however, without significant changes early postop. Late postop significant improvements occurred in other conventional echo indices of LV and RV function as well. There was also a significant correlation between echo-measured LVEF & Fraction Area Change (RV FAC) and MRI-derived LVEF & RVEF, respectively.

CONCLUSION

In this cross-sectional study in rTOF patients, RV and LV GLS as well as conventional echocardiographic indices regarding LV and RV function improved significantly after 6 months (mean = 7.4mo) following PVR.

Right ventricular strain and volume analyses through deep learning-based fully automatic segmentation based on radial long-axis reconstruction of short-axis cine magnetic resonance images

OBJECTIVE

We propose a deep learning-based fully automatic right ventricle (RV) segmentation technique that targets radially reconstructed long-axis (RLA) images of the center of the RV region in routine short axis (SA) cardiovascular magnetic resonance (CMR) images. Accordingly, the purpose of this study is to compare the accuracy of deep learning-based fully automatic segmentation of RLA images with the accuracy of conventional deep learning-based segmentation in SA orientation in terms of the measurements of RV strain parameters.

MATERIALS AND METHODS

We compared the accuracies of the above-mentioned methods in RV segmentations and in measuring RV strain parameters by Dice similarity coefficients (DSCs) and correlation coefficients.

RESULTS

DSC of RV segmentation of the RLA method exhibited a higher value than those of the conventional SA methods (0.84 vs. 0.61). Correlation coefficient with respect to manual RV strain measurements in the fully automatic RLA were superior to those in SA measurements (0.5-0.7 vs. 0.1-0.2).

DISCUSSION

Our proposed RLA realizes accurate fully automatic extraction of the entire RV region from an available CMR cine image without any additional imaging. Our findings overcome the complexity of image analysis in CMR without the limitations of the RV visualization in echocardiography.