Accuracy of right ventricular volume and function assessed with cardiovascular magnetic resonance: comparison with echocardiographic parameters

Cardiac Magnetic Resonance Feature Tracking Analysis for Change in Right Ventricular Function After Cardioplegic Arrest

BACKGROUND

Using echocardiography to assess right ventricular (RV) function after cardioplegic arrest is challenging. Cardiac magnetic resonance (CMR) imaging is a superior alternative, with the feature tracking technique enabling quantitative assessment of myocardial deformation.

METHODS

This single-center, prospective study from 2020 to 2022 assessed RV function in 42 patients who underwent open heart surgery with cardioplegic arrest. CMR data were collected preoperatively, one week postoperatively, and at follow-up (6-12 months after surgery), and assessed using the CMR feature tracking technique.

RESULTS

Postoperatively, there was no significant change in RV end-diastolic volume, but RV end-systolic volume significantly decreased, leading to a notable increase in RV ejection fraction. By follow-up, both RV end-diastolic and end-systolic volumes had significantly reduced compared with the preoperative values. Right ventricular longitudinal contractility decreased after surgery but recovered to the preoperative values by follow-up, while RV circumferential contractility improved postoperatively and remained superior to the preoperative levels at follow-up.

CONCLUSION

On CMR imaging, significant changes in RV systolic motion were observed after cardioplegic arrest, with decreased longitudinal but increased circumferential contractility. At follow up, these changes had reverted to the preoperative patterns by the mid-term (6-12 months).

Cardiac MRI at Low Field Strengths

Cardiac MR imaging is well established for assessment of cardiovascular structure and function, myocardial scar, quantitative flow, parametric mapping, and myocardial perfusion. Despite the clear evidence supporting the use of cardiac MRI for a wide range of indications, it is underutilized clinically. Recent developments in low-field MRI technology, including modern data acquisition and image reconstruction methods, are enabling high-quality low-field imaging that may improve the cost-benefit ratio for cardiac MRI. Studies to-date confirm that low-field MRI offers high measurement concordance and consistent interpretation with clinical imaging for several routine sequences. Moreover, low-field MRI may enable specific new clinical opportunities for cardiac imaging such as imaging near metal implants, MRI-guided interventions, combined cardiopulmonary assessment, and imaging of patients with severe obesity. In this review, we discuss the recent progress in low-field cardiac MRI with a focus on technical developments and early clinical validation studies. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 1.

Right heart failure and patient selection for isolated tricuspid valve surgery

OBJECTIVE

To characterize patients with right heart failure undergoing isolated tricuspid valve surgery, focusing on right heart morphology and function.

PATIENTS AND METHODS

From January 2007 to January 2014, 62 patients underwent isolated tricuspid valve surgery. Forty-five patients (73%) had undergone previous heart operations. Right heart morphology and function variables were measured de novo from stored echocardiographic images, and clinical and hemodynamic data were extracted from patient registries and records. Cluster analysis was performed and outcomes assessed.

RESULTS

On average, the right ventricle was dilated (diastolic area 32 cm2), but its function was preserved (free-wall strain -17% ± 5.8%) and right heart failure manifestations were moderate, with 40 (65%) having congested neck veins, 35 (56%) dependent edema, and 15 (24%) ascites. Average model for end-stage liver disease with sodium score was 11 ± 4.4, but individual values varied widely. Tricuspid valve variables split patients into 2 equal clusters: those with functional tricuspid regurgitation (TR) and those with structural TR. These groups had similar right ventricular function, but the functional TR group had worse right ventricular morphology and more severe manifestations of right heart failure, including greater model for end-stage liver disease with sodium scores (12 ± 44 vs 9.1 ± 3.9; P = .008). Both groups survived operation with low morbidity, but patients with functional TR had worse long-term survival, 48% versus 73% at 10 years after surgery.

CONCLUSIONS

The cluster analysis of patients with right heart failure undergoing isolated tricuspid valve surgery separated functional and structural tricuspid valve disease. Good early outcomes suggest expanding criteria for tricuspid valve surgery and earlier intervention for functional TR with right heart failure.

A new assessment method for right ventricular diastolic function using right heart catheterization by pressure-volume loop

Diastolic stiffness coefficient (β) and end-diastolic elastance (Eed) are ventricular-specific diastolic parameters. However, the diastolic function of right ventricle had not been investigated sufficiently due to the lack of established evaluation method. We evaluated the validity of these parameters calculated using only data of right heart catheterization (RHC) and assessed it in patients with restrictive cardiomyopathy (RCM) and cardiac amyloidosis. We retrospectively analyzed 46 patients with heart failure who underwent RHC within 10 days of cardiac magnetic resonance (CMR). Right ventricular end-diastolic volume and end-systolic volume were calculated using only RHC data, which were found to be finely correlated with those obtained from CMR. β and Eed calculated by this method were also significantly correlated with those derived from conventional method using CMR. By this method, β and Eed were significantly higher in RCM with amyloidosis group than dilated cardiomyopathy group. In addition, the β and Eed calculated by our method were finely correlated with E/A ratio on echocardiography. We established an easy method to estimate β and Eed of right ventricle from only RHC. The method finely demonstrated right ventricular diastolic dysfunction in patients with RCM and amyloidosis.

Free-breathing pseudo-golden-angle bSSFP cine cardiac MRI for biventricular functional assessment in congenital heart disease

PURPOSE

To compare standard breath-hold (BH) cine imaging to a radial pseudo-golden-angle free-breathing (FB) technique in congenital heart disease (CHD).

METHODS

In this prospective study, short-axis and 4-chamber BH and FB cardiac MRI sequences of 25 participants with CHD acquired at 1.5 Tesla, were quantitatively compared regarding ventricular volumes, function, interventricular septum thickness (IVSD), apparent signal to noise ratio (aSNR), and estimated contrast to noise ratio (eCNR). For qualitative comparison, three image quality criteria (contrast, endocardial edge definition, and artefacts) were rated on a 5-point Likert scale (5: excellent, 1: non-diagnostic). Paired t-Test was used for group comparisons, Bland-Altman analysis for agreement between techniques. Inter-reader agreement was compared using intraclass correlation coefficient.

RESULTS

IVSD (BH 7.4 ± 2.1 mm vs FB 7.4 ± 1.9 mm, p =.71), biventricular ejection fraction (left ventricle [LV]: 56.4 ± 10.8% vs 56.1 ± 9.3%, p =.83; right ventricle [RV]: 49.5 ± 8.6% vs 49.7 ± 10.1%, p =.83), and biventricular end diastolic volume (LV: 176.3 ± 63.9 ml vs 173.9 ± 64.9 ml, p =.90; RV: 185.4 ± 63.8 ml vs 189.6 ± 66.6 ml, p =.34) were comparable. Mean measurement time for FB short-axis sequences was 8.1 ± 1.3 compared to 4.4 ± 1.3 min for BH (p <.001). Subjective image quality between sequences was deemed comparable, (4.6 ± 0.6 vs 4.5 ± 0.6, p =.26, for 4-chamber views) with a significant difference regarding short-axis views (4.9 ± 0.3 vs 4.5 ± 0.6, p =.008). aSNR was similar (BH 25.8 ± 11.2 vs FB 22.2 ± 9.5, p =.24), while eCNR was higher for BH (89.1 ± 36.1 vs 68.5 ± 32.1, p =.03).

CONCLUSION

FB sequences yielded comparable results to BH regarding image quality, biventricular volumetry, and function, though measurement times were longer. The FB sequence described might be clinically valuable when BHs are insufficiently performed.

Right ventricular echocardiographic parameters and prediction of stroke volume in ischemic cardiogenic shock: A retrospective study

PURPOSE

This study investigated which commonly used right ventricular (RV) echocardiographic parameter correlates best with stroke volume (SV) estimated by Doppler echocardiography in ischemic cardiogenic shock (CS).

MATERIALS AND METHODS

We retrospectively reviewed the records of 100 patients admitted to the ICU over 34 months with CS. Tricuspid annular plane systolic excursion (TAPSE), Tricuspid annulus systolic velocity (RV S'), Tricuspid regurgitation maximum velocity (TR Vmax), and RV outflow tract velocity time integral (RVOT VTI) were correlated to SV.

RESULTS

Mean age was 62.6 ± 12.7 years and 78% were male. The mean SV, TAPSE, RV S', TR Vmax, and RVOT VTI were 47 ± 16 ml, 16 ± 5 mm, 11 ± 4 mm/s, 1.97 ± 0.73 m/s, and 12.7 ± 5 cm, respectively. RVOT VTI correlated best to SV (r = 0.39 p = 0.01) compared to TAPSE, RV S', and TR Vmax (r = 0.26 p = 0.01, r = 0.15 p = 0.21, r = 0.03 p = 0.78). RVOT VTI independently predicted SV. Univariate analysis demonstrated that only RVOT VTI predicted SV (OD = 1.18 p = 0.04) and had the best area under the curve (0.70, p = 0.03).

CONCLUSION

RVOT VTI correlated better (albeit weakly) to and best predicted SV compared to TAPSE, RV S', and TR Vmax in patients admitted to intensive care with CS. This study suggests that RVOT VTI has the potential as a therapeutic target to optimize SV in CS.

Fast acquisition of left and right ventricular function parameters applying cardiovascular magnetic resonance in clinical routine - validation of a 2-shot compressed sensing cine sequence

Objectives. To evaluate if cine sequences accelerated by compressed sensing (CS) are feasible in clinical routine and yield equivalent cardiac morphology in less time. Design. We evaluated 155 consecutive patients with various cardiac diseases scanned during our clinical routine. LV and RV short axis (SAX) cine images were acquired by conventional and prototype 2-shot CS sequences on a 1.5 T CMR. The 2-shot prototype captures the entire heart over a period of 3 beats making the acquisition potentially even faster. Both scans were performed with identical slice parameters and positions. We compared LV and RV morphology with Bland-Altmann plots and weighted the results in relation to pre-defined tolerance intervals. Subjective and objective image quality was evaluated using a 4-point score and adapted standardized criteria. Scan times were evaluated for each sequence. Results. In total, no acquisitions were lost due to non-diagnostic image quality in the subjective image score. Objective image quality analysis showed no statistically significant differences. The scan time of the CS cines was significantly shorter (p < .001) with mean scan times of 178 ± 36 s compared to 313 ± 65 s for the conventional cine. All cardiac function parameters showed excellent correlation (r 0.978-0.996). Both sequences were considered equivalent for the assessment of LV and RV morphology. Conclusions. The 2-shot CS SAX cines can be used in clinical routine to acquire cardiac morphology in less time compared to the conventional method, with no total loss of acquisitions due to nondiagnostic quality.

TRIAL REGISTRATION

ISRCTN12344380. Registered 20 November 2020, retrospectively registered.

Proof of concept: Comparative accuracy of semiautomated VR modeling for volumetric analysis of the heart ventricles

Introduction

Simpson's rule is generally used to estimate cardiac volumes. By contrast, modern methods such as Virtual Reality (VR) utilize mesh modeling to present the object's surface spatial structure, thus enabling intricate volumetric calculations. In this study, two types of semiautomated VR models for cardiac volumetric analysis were compared to the standard Philips dedicated cardiac imaging platform (PDP) which is based on Simpson's rule calculations.

Methods

This retrospective report examined the cardiac computed tomography angiography (CCTA) of twenty patients with atrial fibrillation obtained prior to a left atrial appendage occlusion procedure. We employed two VR models to evaluate each CCTA and compared them to the PDP: a VR model with Philips-similar segmentations (VR-PS) that included the trabeculae and the papillary muscles within the luminal volume, and a VR model that only included the inner blood pool (VR-IBP).

Results

Comparison of the VR-PS and the PDP left ventricle (LV) volumes demonstrated excellent correlation with a ρc of 0.983 (95% CI 0.96, 0.99), and a small mean difference and range. The calculated volumes of the right ventricle (RV) had a somewhat lower correlation of 0.89 (95% CI 0.781, 0.95), a small mean difference, and a broader range. The VR-IBP chamber size estimations were significantly smaller than the estimates based on the PDP.

Discussion

Simpson's rule and polygon summation algorithms produce similar results in normal morphological LVs. However, this correlation failed to emerge when applied to RVs and irregular chambers.

Conclusions

The findings suggest that the polygon summation method is preferable for RV and irregular LV volume and function calculations.

Comparison of Cadmium Zinc Telluride ECG-gated SPECT equilibrium radionuclide angiocardiography to magnetic resonance imaging to measure right ventricular volumes and ejection fraction in patients with cardiomyopathy

AIMS

The objective of this study was to determine the accuracy of right ventricular function (RVF) assessed by Cadmium Zinc Telluride ECG-gated SPECT equilibrium radionuclide angiocardiography (CZT-ERNA).

METHODS AND RESULTS

Twenty-one consecutive patients with cardiomyopathy (aged 54 ± 19 years; 62% male) were included. RV ejection fraction (EF) and volumes were analyzed by CZT-ERNA and compared with values obtained by cardiac magnetic resonance imaging (CMR). Mean values were not different between CZT-ERNA and MRI for RVEF (48.1 ± 10.4% vs 50.8 ± 10.0%; P = .23). Significant correlations (P < .0001) were observed between CZT-ERNA and MRI for RVEF, RV end-diastolic volume, and end-systolic volume (r = 0.81, r = 0.93, and r = 0.96, respectively). Bland-Altman analysis showed a mean difference (bias) between CZT-ERNA and MRI for RVEF of -2.69% (95% CI - 5.35 to - 0.42) with good agreement between the 2 techniques (limits of agreement, -14.3 to 8.99). Intraobserver and interobserver reproducibility of RVF measured by CZT-ERNA was high.

CONCLUSION

CZT-ERNA provides accurate, reproducible assessment of RVF and appears as a good alternative to cardiac magnetic resonance for the evaluation of the magnitude of RVF in patients with cardiomyopathy.

Right ventricular function in β-thalassemia children: comparing three-dimensional echocardiography with other functional parameters

BACKGROUND

Cardiomyopathy is a major cause of mortality and morbidity in beta-thalassemia major (β-TM), and its early detection is critical for prompt management. We aimed to evaluate right ventricle (RV) function in β-TM, in absence of cardiac symptoms, using 3D echocardiography, and compare it with other functional parameters.

METHODS

Cross-sectional cohort study was conducted on 50 β-TM children with no cardiac manifestations and 50 healthy controls of matched age and sex. We evaluated RV function using; Fraction Area Change (2DE-RV FAC), Ejection Fraction (3D-RVEF), Tricuspid annular plane systolic excursion (TAPSE), Tissue Doppler imaging (TDI) systolic (S') and diastolic (E', A'), Myocardial performance index (MPI), and speckle tracking (2D-STE) of RV global longitudinal strain (LSS), systolic strain rate (SSR), early diastolic strain rate (DSR E), and late diastolic strain rate (DSR A).

RESULTS

3D-RVEF, MPI, and 2D-STE showed significant differences between the two groups. ROC curve analysis measurements had an AUC above 0.7-which indicate at least a fair discriminatory power between the β-TM group with RV dysfunction and normal controls.

CONCLUSIONS

β-TM patients have decreased RV function indices at a pre-symptomatic stage. Early detection of RV dysfunction is feasible and can allow for closer follow-up to detect pre-clinical changes.

IMPACT

The key message of this article is to emphasize the importance of the evaluation of right ventricular function in children with beta-thalassemia major. This article adds to the existing literature the use of recent echocardiographic modalities as three-dimensional echocardiography and two-dimensional speckle tracking in the evaluation of right ventricular dysfunction in beta-thalassemia children while cardiac affection is still subclinical.

IMPACT

Recent echocardiographic functional parameters can be effectively used to evaluate the right ventricle in beta-thalassemia and can detect dysfunction in asymptomatic patients allowing for early intervention.

Noninvasive Assessment of Right Ventricle Function and Pulmonary Artery Pressure Using Transthoracic Echocardiography in Women With Pre-Eclampsia: An Exploratory Study

Background and objective

Pre-eclampsia (PEC) is associated with the release of anti-angiogenic factors that are incriminated in raising systemic and pulmonary vascular resistance (PVR). Compared to the left heart and systemic circulation, much less attention has been paid to the right heart and pulmonary circulation in patients with PEC. We used transthoracic echocardiography (TTE) to estimate pulmonary artery (PA) pressure and right ventricular (RV) function in women with PEC.

Materials and methods

We conducted a case-control study at a tertiary care academic center. Ten early PEC (<34-week gestation) and nine late PEC (≥34-week gestation) patients with 11 early and 10 late gestational age-matched controls were enrolled. Two-dimensional TTE was performed on all patients. The estimated mean PA pressure (eMPAP) was calculated based on PA acceleration time (PAAT). PVR was estimated from eMPAP and RV cardiac output (RV CO). RV myocardial performance index (RV MPI), tricuspid annular plane systolic excursion (TAPSE), tissue tricuspid annular displacement (TTAD), and lateral tricuspid annular tissue peak systolic velocity (S’) were measured.

Results

Compared to early controls, in early PEC, the eMPAP and estimated PVR (ePVR) were elevated, PAAT was reduced, RV MPI was increased, TTAD was reduced, and TAPSE and TV S’ were unchanged. Compared to late controls, in late PEC, the eMPAP and ePVR were elevated, PAAT was reduced, and RV MPI was increased, while TAPSE, TTAD, and TV S’ were unchanged.

Conclusions

In a sample of women with PEC, early PEC was found to be associated with increased eMPAP and ePVR and subclinical decrement of RV function as assessed by TTE. TTE may be a useful noninvasive screening tool for early detection of pulmonary hypertension and RV dysfunction in PEC. An adequately powered longitudinal study is needed to determine the implications of these findings on long-term outcomes.