Changes in left and right ventricular longitudinal function after pulmonary valve replacement in patients with Tetralogy of Fallot

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.

Non-invasive pressure-volume loops show high arterial elastance in children with repaired tetralogy of Fallot

BACKGROUND

Children with repaired tetralogy of Fallot (rToF) often have pulmonary regurgitation with right ventricular (RV) dilatation and dysfunction, whereas less is known about the effect on the left ventricle (LV). The aim was to investigate LV haemodynamic variables derived from non-invasive pressure-volume loops in children with rToF and how they compare to controls and previous research on adults.

MATERIALS AND METHODS

Ten children with rToF and pulmonary regurgitation (12 years [10-13], 6 males) and 10 age- and sex-matched healthy controls (12 years [10-14], 6 males) underwent brachial blood pressure in conjunction with cardiac magnetic resonance imaging. Pressure-volume loops were derived by brachial blood pressure together with LV volumes throughout the cardiac cycle in short-axis cine images yielding several haemodynamic variables, including arterial elastance. The RV endocardial border was delineated in end-diastole and end-systole.

RESULTS

Children with rToF and pulmonary regurgitation had larger RV end-diastolic volume (136 [114-156]) than controls (100 [94-112] ml/m2; p = 0.0015) and smaller LV end-diastolic volume (83 [58-91] ml/m2) than controls (101 [92-110] ml/m2; p = 0.002). Arterial elastance was higher in children with rToF (1.5 [1.3-2.7] mmHg/ml) than in controls (1.1 [1.0-1.5] mmHg/ml; p = 0.02). Heart rate was higher in children with rToF (77 [74-81] bpm) than in controls (69 [65-75] bpm; p = 0.027).

CONCLUSION

Children with rToF had higher arterial elastance and heart rate than controls, likely due to increased sympathetic tone to compensate for impaired LV filling following pulmonary regurgitation. If this contributes to increased risk of adverse cardiovascular and cerebrovascular events remains to be studied.

Prognostic value of myocardial deformation parameters for outcome prediction in tetralogy of Fallot

BACKGROUND

The prognostic value of myocardial deformation parameters in adults with repaired tetralogy of Fallot (rTOF) has not been well-elucidated. We therefore aimed to explore myocardial deformation parameters for outcome prediction in adults with rTOF using cardiovascular magnetic resonance imaging (CMR).

METHODS

Adults with rTOF and at least moderate pulmonary regurgitation were identified from an institutional prospective CMR registry. Left ventricular (LV) and right ventricular (RV) global strains were recorded in longitudinal (GLS), circumferential (GCS), and radial (GRS) directions. Major adverse cardiovascular events (MACE) were defined as a composite of mortality, resuscitated sudden death, sustained ventricular tachycardia (>30 seconds), or heart failure (hospital admission >24 hours). In patients with pulmonary valve replacement (PVR), pre- and post-PVR CMR studies were analyzed to assess for predictors of complete RV reverse remodeling, defined as indexed RV end-diastolic volume (RVEDVi) <110 mL/m2. Logistic regression models were used to estimate the odds ratio (OR) per unit change in absolute strain value associated with clinical outcomes and receiver operator characteristic curves were constructed with area under the curve (AUC) for select CMR variables.

RESULTS

We included 307 patients (age 35 ± 13 years, 59% (180/307) male). During 6.1 years (3.3-8.8) of follow-up, PVR was performed in 142 (46%) and MACE occurred in 31 (10%). On univariate analysis, baseline biventricular ejection fraction (EF), mass, and all strain parameters were associated with MACE. After adjustment for LVEF, only LV-GLS remained independently predictive of MACE (OR 0.822 [0.693-0.976] p = 0.025). Receiver operator curves identified an absolute LV-GLS value less than 15 and LVEF less than 51% as thresholds for MACE prediction (AUC 0.759 [0.655-0.840] and 0.720 [0.608-0.810]). After adjusting for baseline RVEDVi, RV-GCS (OR 1.323 [1.094-1.600] p = 0.004), LV-GCS (OR 1.276 [1.029-1.582] p = 0.027) and LV-GRS (OR 1.101 [1.0210-1.200], p = 0.028) were independent predictors of complete remodeling post-PVR remodeling.

CONCLUSION

Biventricular strain parameters predict clinical outcomes and post-PVR remodeling in rTOF. Further study will be necessary to establish the role of myocardial deformation parameters in clinical practice.

Patients with volume-loaded right ventricle - quantification of left ventricular hemodynamic response to intervention measured by noninvasive pressure-volume loops

Volume loading of the right ventricle (RV) in patients with atrial septal defect (ASD) and patients with repaired Tetralogy of Fallot (rToF) affects the pumping mechanics of the left ventricle (LV). Intervention of the lesion will relieve the RV volume load however quantifiable impact on exercise capacity, arrhytmias or death are limited. A possible explanation could be remaining effects on the function of the LV. The aim of this study was therefore to investigate if hemodynamics of the LV differs between patients with RV volume load due to ASD or rToF and healthy controls and if they change after intervention. Eighteen patients with ASD, 17 patients with rToF and 16 healthy controls underwent cardiac magnetic resonance imaging (CMR) and maximal exercise test with continuous gas analysis. Reexamination was performed 13 ± 2 months after closure of the ASD in 13 of the patients and 10 ± 4 months after pulmonary valve replacement (PVR) in 9 of the patients with rToF. Non-invasive PV-loops from CMR and brachial pressures were analyzed. Stroke work (SW) and potential energy (PE) increased after ASD closure but not in ToF patients after valve repair. Patients with ASD or rToF had higher contractility and arterial elastance than controls. No major effects were seen in LV energetics or in peak VO2 after ASD closure or PVR. Peak VO2 correlated positively with SW and PE in patients with ASD (r = 0.54, p < 0.05; r = 0.61, p < 0.01) and controls (r = 0.72, p < 0.01; r = 0.53, p < 0.05) to approximately the same degree as peak VO2 and end-diastolic volume (EDV) or end-systolic volume (ESV). In ToF patients there was no correlation between PV loop parameters and peak VO2 even if correlation was found between peak VO2 and EDV or ESV. In conclusion, the LV seems to adapt its pumping according to anatomic circumstances without losing efficiency, however there are indications of persistent vascular dysfunction, expressed as high arterial elastance, which might have impact on exercise performance and prognosis. Future studies might elucidate if the duration of RV volume load and decreased LV filling have any impact on the ability of the vascular function to normalize after ASD closure or PVR.

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 longitudinal function is linked to left ventricular filling pressure in patients with repaired tetralogy of fallot

Experimental data on pulmonary regurgitation has linked right ventricular longitudinal function to left ventricular filling pressure in animals with induced and treated pulmonary regurgitation but this relationship has not been investigated in patients with repaired Tetralogy of Fallot (rToF). The aim of this study was to determine if right ventricular longitudinal function assessed using cardiovascular magnetic resonance (CMR) is associated with left ventricular filling pressure in patients with rToF. A second objective of this study was to determine if direction of septal movement is related to right ventricular pressure load in rToF. Eighteen patients with rToF undergoing CMR and heart catheterization prior to pulmonary valve replacement were retrospectively included and catheter-based pressure measurements were compared with CMR-derived RV regional function. Left ventricular filling pressure was measured as precapillary wedge pressure (PCWP). Longitudinal contribution to RV stroke volume correlated with PCWP (r = 0.48; p = 0.046) but not with RV EF or pulmonary regurgitation. Neither RV longitudinal strain nor TAPSE showed correlation with PCWP. Longitudinal contribution to stroke volume was lower for the RV compared to the LV (49 vs 54%; p = 0.039). Direction of septal movement did not show a correlation with RV end-systolic pressure. Right ventricular longitudinal pumping is associated with left ventricular filling pressure in rToF-patients and this inter-ventricular coupling may explain LV underfilling in patients with pulmonary regurgitation and rToF and may be of value to determine right ventricular dysfunction. RV systolic pressure, however, cannot be assessed from the direction of septal movement, in these patients.

Ventricular longitudinal shortening is an independent predictor of death in heart failure patients with reduced ejection fraction

Reduced ventricular longitudinal shortening measured by atrioventricular plane displacement (AVPD) and global longitudinal strain (GLS) are prognostic markers in heart disease. This study aims to determine if AVPD and GLS with cardiovascular magnetic resonance (CMR) are independent predictors of cardiovascular (CV) and all-cause death also in heart failure with reduced ejection fraction (HFrEF). Patients (n = 287) were examined with CMR and AVPD, GLS, ventricular volumes, myocardial fibrosis/scar were measured. Follow-up was 5 years with cause of death retrieved from a national registry. Forty CV and 60 all-cause deaths occurred and CV non-survivors had a lower AVPD (6.4 ± 2.0 vs 8.0 ± 2.4 mm, p < 0.001) and worse GLS (− 6.1 ± 2.2 vs − 7.7 ± 3.1%, p = 0.001). Kaplan–Meier analyses displayed increased survival for patients in the highest AVPD- and GLS-tertiles vs. the lowest tertiles (AVPD: p = 0.001, GLS: p = 0.013). AVPD and GLS showed in univariate analysis a hazard ratio (HR) of 1.30 (per-mm-decrease) and 1.19 (per-%-decrease) for CV death. Mean AVPD and GLS were independent predictors of all-cause death (HR = 1.24 per-mm-decrease and 1.15 per-%-decrease), but only AVPD showed incremental value over age, sex, body-mass-index, EF, etiology and fibrosis/scar for CV death (HR = 1.33 per-mm-decrease, p < 0.001). Ventricular longitudinal shortening remains independently prognostic for death in HFrEF even after adjusting for well-known clinical risk factors.