Annular Tilt as a Screening Test for Right Ventricular Enlargement in Patients with Tetralogy of Fallot

Tricuspid valve annular tilt for assessment of pre- and post-intervention right ventricular volume in patients undergoing transcatheter pulmonary valve replacement

INTRODUCTION

Transcatheter pulmonary valve replacement serves as a successful alternative to surgical replacement of a right ventricle to pulmonary artery conduit. Guidelines for recommending transcatheter pulmonary valve replacement depend on MRI right ventricular volumes, which have been correlated to the echocardiographic measure of right ventricular annular tilt. We aim to assess whether right ventricular annular tilt can be a clinically useful alternative tool in the acute and long-term periods after transcatheter pulmonary valve replacement to assess right ventricular health.

METHODS

We reviewed 70 patients who underwent transcatheter pulmonary valve replacement at a single institution. Echocardiographic measurements were obtained prior to transcatheter pulmonary valve replacement, immediately after transcatheter pulmonary valve replacement, and within 6 months to 1 year after transcatheter pulmonary valve replacement. Right ventricular annular tilt measures the angle of the tricuspid valve plane relative to the mitral valve plane at end-diastole in the apical four-chamber view. Right ventricular fractional area change, right ventricular systolic strain, tissue Doppler velocity, and tricuspid annular plane systolic excursion Z-scores were obtained using published methods.

RESULTS

Right ventricular annular tilt decreased significantly immediately after transcatheter pulmonary valve replacement (p = 0.0004), and this reduction in right ventricular volume persisted at the mid-term follow-up (p < 0.0001). Fractional area change did not change significantly after transcatheter pulmonary valve replacement while right ventricular global strain improved at mid-term follow-up despite no significant difference immediately after transcatheter pulmonary valve replacement.

CONCLUSIONS

Right ventricular annular tilt decreases both immediately after transcatheter pulmonary valve replacement and at mid-term follow-up. Right ventricular strain also improved after transcatheter pulmonary valve replacement, corresponding to the improved volume load. Right ventricular annular tilt can be considered as an additional echocardiographic factor to assess right ventricular volume and remodeling after transcatheter pulmonary valve replacement.

Early Right Heart Chambers Reverse Remodeling in Patients Operated in Adulthood for Congenital Lesions Associated with Right Heart Chambers Enlargement

BACKGROUND

Progressive right heart chambers dilatation is frequent in the adult congenital heart disease (ACHD) population. We evaluated the immediate and mid-term response of right heart chambers to surgery performed in adulthood for lesions associated with right heart chambers enlargement.

METHODS

Thirty-six adult patients with lesions associated with right heart chambers enlargement submitted to surgery were studied. We collected echocardiographic data of right ventricle (RV) mid-diameter, right atrial volume indexed, RV systolic pressure, and tricuspid annular plane systolic excursion (TAPSE) prior to surgery (T0), at 2 to 5 days (T1), and 3 to 6 months (T2) after surgery.

RESULTS

At T1, we observed a significant decrease of RV mid-diameter (47.2 ± 8.4 vs. 39.6 ± 7.4 mm, P < .001), right atrial volume indexed (45.6 ± 26.6 vs. 27.2 ± 11 ml/m2, P < .001), and RV systolic pressure (39 ± 14.8 vs. 32.8 ± 11.3 mm Hg, P = .03). At T2, a further significant deviation in the rate of RV diameter (39.6 ± 7.4 vs. 34.5 ± 5.1 mm, P < .001), in RV systolic pressure (32.8 ± 11.3 vs. 25.3 ± 5 mm Hg, P = .03) and TAPSE (13.9 ± 3.2 vs. 15.8 ± 2.6 mm, P < .001) was observed.

CONCLUSIONS

Positive right heart chambers remodeling occurs as early as in the immediate post-operative period in most ACHD patients operated for lesions associated with right heart chambers enlargement.

Reproducibility and Agreement of Tissue Tracking versus Feature Tracking for Strain Measurement on Cardiac MR Images in Patients with Repaired Tetralogy of Fallot

PURPOSE

To evaluate differences in strain measurements by using tissue-tracking (TT) and feature-tracking (FT) software on cardiovascular MR images in patients with repaired tetralogy of Fallot (TOF).

MATERIALS AND METHODS

In this retrospective cross-sectional study of 25 patients with repaired TOF (median age, 33.1 years; interquartile range, 25.3-38.3 years) from 2008 through 2014, left ventricular (LV) and right ventricular (RV) global circumferential and longitudinal strain were measured from cardiac MR images by using TT and FT software. Time to process was measured from opening the study to acceptance of contours. Intra- and interobserver reproducibility were evaluated with Bland-Altman analysis, coefficient of variation, and intraclass correlation coefficient.

RESULTS

Time to process was slightly longer for TT (10.2 minutes ± 3.1 [standard deviation] vs 9.0 minutes ± 1.7, P = .04). Fewer patients required contour revision with TT than with FT. Both TT and FT measurements had similar moderate-to-strong correlations with LV and RV ejection fractions; correlation of RV longitudinal strain with RV ejection fraction did not reach significance by using either method. With the exception of LV circumferential strain, strain measurements were lower with FT relative to TT. Intra- and interobserver reproducibility were lower with FT for longitudinal strain measurements.

CONCLUSION

TT and FT have systematic differences in strain values and reproducibility, particularly for longitudinal strain. Software-specific normative data are necessary, as are studies to evaluate correlation with clinical outcomes for each modality.© RSNA, 2019.

Short-Axis Diastolic Ventricular Area Ratio as a New Index in Screening Patients with Repaired Tetralogy of Fallot

Right ventricular (RV) end-diastolic volume measured by cardiovascular magnetic resonance imaging (CMR) is a criterion for pulmonary valve replacement in patients with tetralogy of Fallot (TOF). We sought to determine if the ratio of echocardiographic, short-axis RV-to-left ventricular (LV) end-diastolic areas (EDA) could be used to predict RV volume on CMR. We retrospectively reviewed the echocardiograms of all patients with repaired TOF who underwent CMR at our institution from 2011 to 2015 and also had an echocardiogram within 6 months of the CMR. The short-axis RV and LV EDAs were measured and the ratio of the two was calculated. Results were compared with CMR RV end-diastolic volume index (RVEDVi) and RV:LV end-diastolic volume ratio. The sensitivity and specificity values predicting RV volumes > 150 ml/m² were calculated. Fifty-eight studies met inclusion criteria. There were 47 studies with RVEDVi < 150 ml/m² and 11 with RVEDVi > 150 ml/m². RV:LV EDA and CMR RV:LV end-diastolic volume ratio correlated strongly (r = 0.76, p < 0.0001). An RV:LV EDA ≥ 1.57 had a 90% sensitivity to predict RVEDVi > 150 ml/m² (area under the curve = 0.74, 95% CI 1.5-27.9; p = 0.012). An RV:LV EDA ≥ 1.88 had an 81% specificity to detect RV volume index > 150 ml/m². Short-axis RV:LV EDA correlates well with an increased RVEDVi as measured by CMR. This new and simple measure can be used to predict optimal timing for CMR in anticipation of pulmonary valve replacement in repaired TOF.

Abnormalities in Left Ventricular Rotation Are Inherent in Young Children with Repaired Tetralogy of Fallot and Are Independent of Right Ventricular Dilation

Left ventricular (LV) dysfunction is a risk factor for adverse outcomes in older children and adults with repaired Tetralogy of Fallot (rToF). Pulmonary regurgitation (PR), right ventricular (RV) dilation, and dysfunction have been shown to result in abnormal LV myocardial mechanics and dysfunction. The aim of our study was to evaluate LV rotational mechanics, especially apical rotation in young children with rToF with and without RV dilation. This is a retrospective, single center study in 28 asymptomatic young children with rToF (16 with RV dilation; 12 without RV dilation); 29 age-matched normal controls. RV and LV systolic and diastolic function was studied using conventional two-dimensional echocardiography (2DE) and speckle tracking echocardiography (STE). Rotational mechanics studied included basal and apical rotation (BR, AR), peak twist (calculated by difference between the apical and basal rotation), twist rate (TR), and untwist rate (UnTR). The mean age of the cohort was 4.7 years (± 2.3). Abnormal AR, BR, TR, and UnTR were noted in patients with rToF. The abnormalities were significant in magnitude as well as the direction of rotation; more pronounced in the absence of RV dilation. LV systolic and diastolic dysfunction as evidenced by abnormal AR and degree of untwist is inherent in rToF and not associated with RV dilation in rToF children. Abnormal BR may reflect a lack of maturation to adult type of rotational mechanics. Further longitudinal studies are required to study the progression of these abnormalities and their correlation with clinical outcomes.

Improving the role of echocardiography in studying the right ventricle of repaired tetralogy of Fallot patients: comparison with cardiac magnetic resonance

Right ventricular (RV) evaluation represents one of the major clinical tasks in the follow-up of repaired tetralogy of Fallot patients (rToF) with pulmonary valve regurgitation, as both severe RV dilatation and dysfunction are key factors in defining the need of pulmonary valve replacement. The aim of our study was to report the diagnostic accuracy of echocardiography in the identification of rToF patients with severely dilated and/or depressed RV as compared to cardiac magnetic resonance (CMR). Among our patients with rToF, a subgroup of 95 (17.6 ± 6.8 years; 60% male), who underwent right ventricular qualitative and quantitative evaluation with CMR following echocardiographic suspicion of severe dilation/dysfunction, were included in the analysis. When comparing echocardiographic RV functional parameters to CMR findings, we found no association between CMR-ejection fraction (EF) and either tricuspid annulus plane systolic excursion (TAPSe) nor tissue Doppler systolic tricuspid excursion velocity (all p = ns). In contrast RVFAC was strongly associated with CMR-EF (r = 0.44; p < 0.01) as well as to longitudinal components of RV mechanics including tissue Doppler s' (r = 0.40; p < 0.01) and TAPSE (r = 0.36; p < 0.01). When comparing echocardiographic and CMR structural parameters of the RV, we found that CMR RV volume was strongly related to echocardiographic measurements of RV end diastolic area (from the 4 chamber apical view) and with proximal parasternal short axis right ventricle outflow-dimension. Accordingly a regression model was derived from multiple regression analysis, which allows a more accurate estimate of CMR RV volume from echocardiography (r² = 0.59, p < 0.001). Our study demonstrates a significant, although imperfect, correlation between echocardiographic and CMR RV functional and geometrical parameters. Combining echocardiographic measures of RV inflow and RV outflow, we deliver a simple formula to estimate CMR-RV volume, improving the echocardiographic accuracy in RV volume quantification.

Right Ventricular Apical Flattening as an Echocardiographic Screening Tool for Right Ventricular Enlargement

Right ventricular dilation is a common complication after tetralogy of Fallot (TOF) repair. Traditional echocardiographic assessments are imprecise due to the RV's location and complex geometry. We propose a novel echocardiographic measurement: RV apical flattening (RVAF) as a screening tool to help identify subjects with severe RV dilation. Patients with repaired TOF who had both echocardiograms and CMR's within 6-month interval at our institution were included in the study. The RVAF was measured in the four-chamber echocardiographic view as the minor length of RV cavity at the level of RV apical endocardium. Subjects were divided into two groups (group I: RVEDVi ≥ 150 ml/m(2) and group II; RVEDVi < 150 ml/m(2)). Echocardiogram and CMR data were compared between groups. A total of 75 subjects were included in the study. Mean age was 12.8 ± 3.6 years. Group I had 36 subjects, and group II had 39 subjects. The mean RVAF was significantly higher in group I (2.7 ± 0.5 cm) compared with group II (1.7 ± 0.4 cm; p < 0.001). There was significant correlation between RVAF and RVEDVi (r = 0.81; p < 0.001). By ROC analysis, an RVAF cutoff value of 2.0 cm had 94 % sensitivity and 77 % specificity in identifying severe RV dilation (area under the curve 0.95). RVAF is a simple and effective echocardiographic screening tool to help identify severe RV dilation. In conjunction with other 2D echocardiographic parameters, this technique would help further refine echocardiography-guided patient selection for timing of CMR and pulmonary valve replacement.

Echocardiographic Parameters of Right Ventricular Diastolic Function in Repaired Tetralogy of Fallot Are Associated with Important Findings on Magnetic Resonance Imaging

BACKGROUND

Right ventricular (RV) dilation, RV dysfunction, RV outflow tract obstruction, and branch pulmonary artery stenosis are risk factors associated with the need for future surgical or catheter-based intervention commonly assessed by cardiac magnetic resonance in patients with tetralogy of Fallot who have undergone initial repair. The ability of echocardiography to predict the presence of these risk factors is limited.

OBJECTIVE

We aimed to determine the association between echocardiographic parameters of right ventricular diastolic dysfunction and risk factors for intervention as identified on cardiac magnetic resonance imaging (CMR).

DESIGN

We reviewed all echocardiograms and CMRs performed at our institution within 1 year of each other in patients with repaired tetralogy of Fallot. We evaluated patients for the following: RV systolic dysfunction (RV ejection fraction <45%), RV dilation (right ventricular end-diastolic volume ≥ 160 mL/m(2)), and RV obstruction (RV outflow tract gradient ≥ 3 m/s by echocardiogram or branch pulmonary artery stenosis assessed by CMR). We evaluated for associations between the above CMR findings and echocardiographic parameters of diastolic function.

RESULTS

CMR and echocardiographic images performed between March 2007 and March 2012 were available in 99 patients. RV obstruction was associated with lower E/A ratio (P = .02), E/A reversal (P = .02), and prograde end diastolic pulmonary flow (P < .01). Low tricuspid annular a' and low septal s' were associated with lower RV ejection fraction (P < .01, P < .01). Elevated E/e' was associated with higher RV end diastolic volume (P = .04). In predicting the presence of any of the evaluated risk factors for future intervention, TV E/e' ≥ 4.7 had positive predictive value (PPV) of 86% and negative predictive value (NPV) of 50%, TV E/A reversal had PPV of 89% and NPV of 34, and prograde end diastolic pulmonary flow on echocardiogram had PPV of 91% and NPV of 38%.

CONCLUSIONS

Echocardiographic parameters of diastolic dysfunction have a reasonable PPV but poor NPV for predicting clinically significant risk factors identified by CMR.

Relationship between echocardiographic and magnetic resonance derived measures of right ventricular size and function in patients with pulmonary hypertension

BACKGROUND

Transthoracic echocardiographic (TTE) imaging is the mainstay of clinical practice for evaluating right ventricular (RV) size and function, but its accuracy in patients with pulmonary hypertension has not been well validated.

METHODS

Magnetic resonance imaging (MRI) and TTE images were retrospectively reviewed in 40 consecutive patients with pulmonary hypertension. RV and left ventricular volumes and ejection fractions were calculated using MRI. TTE areas and indices of RV ejection fraction (RVEF) were compared.

RESULTS

The average age was 42 ± 12 years, with a majority of women (85%). There was a wide range of mean pulmonary arterial pressures (27-81 mm Hg) and RV end-diastolic volumes (111-576 mL), RVEFs (8%-67 %), and left ventricular ejection fractions (26%-72%) by MRI. There was a strong association between TTE and MRI-derived parameters: RV end-diastolic area (by TTE imaging) and RV end-diastolic volume (by MRI), R(2) = 0.78 (P < .001); RV fractional area change by TTE imaging and RVEF by MRI, R(2) = 0.76 (P < .001); and tricuspid annular plane systolic excursion by TTE imaging and RVEF by MRI, R(2) = 0.64 (P < .001). By receiver operating characteristic curve analysis, an RV fractional area change < 25% provided excellent discrimination of moderate systolic dysfunction (RVEF < 35%), with an area under the curve of 0.97 (P < .001). An RV end-diastolic area index of 18 cm(2)/m(2) provided excellent discrimination for moderate RV enlargement (area under the curve, 0.89; P < .001).

CONCLUSIONS

Echocardiographic estimates of RV volume (by RV end-diastolic area) and function (by RV fractional area change and tricuspid annular plane systolic excursion) offer good approximations of RV size and function in patients with pulmonary hypertension and allow the accurate discrimination of normal from abnormal.

Usefulness of right ventricular free wall strain to predict quality of life in "repaired" tetralogy of Fallot

After repair of tetralogy of Fallot, the left ventricular ejection fraction and the right ventricular ejection fraction are associated with clinical status and outcomes, but the relation of strain, a potentially earlier marker of dysfunction, to quality of life has not been evaluated. In 58 patients with tetralogy of Fallot (median age 29 years, interquartile range 20 to 41) who underwent cardiovascular magnetic resonance imaging and completed the Short Form 36, Version 2 (a validated quality-of-life assessment), left ventricular global circumferential strain, left ventricular global longitudinal strain, and right ventricular free wall longitudinal strain (RVLSFW) were measured from cine images using feature-tracking software. Age-adjusted z score ≤-1 for the physical component summary or subscales of physical functioning, role-physical, and general health was considered a clinically significant decrease in quality of life. Patients with RVLSFW less than the median had increased odds of decreased physical functioning (odds ratio [OR] 5.4, p = 0.01) and general health (OR 3.5, p = 0.04) subscale scores, which remained significant in patients with right ventricular ejection fractions ≥45% (physical functioning: OR 9.5, p = 0.03; general health: OR 5.9, p = 0.04). Left ventricular global circumferential strain and left ventricular global longitudinal strain did not predict decreased quality of life in this population. Intraobserver and interobserver variability was acceptable for left ventricular global circumferential strain (coefficients of variation 9.5% and 10.0%, respectively) but lower for left ventricular global longitudinal strain (coefficients of variation 17.2% and 16.8%, respectively) and poor for RVLSFW (coefficients of variation 19.9% and 28.8%, respectively). In conclusion, RVLSFW appears to have discriminative ability in this population for decreased quality of life and may yield incremental prognostic value beyond global right ventricular ejection fraction assessment, but further study is needed to evaluate methods to limit variability.