Impact of abnormal longitudinal rotation on the assessment of right ventricular systolic function in patients with severe pulmonary hypertension

Deep learning to assess right ventricular ejection fraction from two-dimensional echocardiograms in precapillary pulmonary hypertension

BACKGROUND

Precapillary pulmonary hypertension (PH) is characterized by a sustained increase in right ventricular (RV) afterload, impairing systolic function. Two-dimensional (2D) echocardiography is the most performed cardiac imaging tool to assess RV systolic function; however, an accurate evaluation requires expertise. We aimed to develop a fully automated deep learning (DL)-based tool to estimate the RV ejection fraction (RVEF) from 2D echocardiographic videos of apical four-chamber views in patients with precapillary PH.

METHODS

We identified 85 patients with suspected precapillary PH who underwent cardiac magnetic resonance imaging (MRI) and echocardiography. The data was divided into training (80%) and testing (20%) datasets, and a regression model was constructed using 3D-ResNet50. Accuracy was assessed using five-fold cross validation.

RESULTS

The DL model predicted the cardiac MRI-derived RVEF with a mean absolute error of 7.67%. The DL model identified severe RV systolic dysfunction (defined as cardiac MRI-derived RVEF < 37%) with an area under the curve (AUC) of .84, which was comparable to the AUC of RV fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE) measured by experienced sonographers (.87 and .72, respectively). To detect mild RV systolic dysfunction (defined as RVEF ≤ 45%), the AUC from the DL-predicted RVEF also demonstrated a high discriminatory power of .87, comparable to that of FAC (.90), and significantly higher than that of TAPSE (.67).

CONCLUSION

The fully automated DL-based tool using 2D echocardiography could accurately estimate RVEF and exhibited a diagnostic performance for RV systolic dysfunction comparable to that of human readers.

Right ventricle: current knowledge of echocardiographic evaluation of this "forgotten" chamber

In the past the right ventricle (RV) has been traditionally regarded as a simple conduit between the venous system and the pulmonary circulation and it has aroused little interest in both clinical and echocardiographic cardiologists to such an extent that it has been defined as the "forgotten chamber." Subsequently it was clearly shown that the right heart (RH) plays an important physiologic role in cardiac activity, and that congenital or acquired alterations in its structure and function have an important prognostic value. Aim of this review is to shed the light on the echocardiographic approach to this cardiac chamber. In this narrative review we critically explored the most recent literature on this topic using PubMed and Medline and examining the most recent guidelines on the echocardiographic approach to the RV. Echocardiographic approach to RV presents some technical difficulties, which stem from the position of the RV inside the thorax and around the LV and from its particular anatomy, which precludes geometric assumptions. However, RV may now be evaluated quantitatively and qualitatively in many ways, and some new methods can partially overcome some of the limits imposed by its complex anatomy, thereby yielding a quantitative evaluation. Furthermore, due to the wide range of pathologies which may involve the RV a disease-oriented approach should be considered in the echocardiographic investigation of right heart disease.

The value of right ventricular to pulmonary arterial coupling in the critically ill: a National Echocardiography Database of Australia (NEDA) substudy

BACKGROUND

Right ventricular (RV) function is tightly coupled to afterload, yet echocardiographic indices of RV function are frequently assessed in isolation. Normalizing RV function for afterload (RV-PA coupling) using a simplified ratio of tricuspid annular plane systolic excursion (TAPSE)/ tricuspid regurgitant velocity (TRV) could help to identify RV decompensation and improve risk stratification in critically ill patients. This is the first study to explore the distribution of TAPSE/TRV ratio and its prognostic relevance in a large general critical care cohort.

METHODS

We undertook retrospective analysis of echocardiographic, clinical, and mortality data of intensive care unit (ICU) patients between January 2012 and May 2017. A total of 1077 patients were included and stratified into tertile groups based on TAPSE/TRV ratio: low (< 5.9 mm.(m/s)-1), middle (≥ 5.9-8.02 mm.(m/s)-1), and high (≥ 8.03 mm.(m/s)-1). The distribution of the TAPSE/TRV ratio across ventricular function subtypes of normal, isolated left ventricular (LV), isolated RV, and biventricular dysfunction was explored. The overall prognostic relevance of the TAPSE/TRV ratio was tested, including distribution across septic, cardiovascular, respiratory, and neurological subgroups.

RESULTS

Higher proportions of ventricular dysfunctions were seen in low TAPSE/TRV tertiles. TAPSE/TRV ratio is impacted by LV systolic function but to a lesser extent than RV dysfunction or biventricular dysfunction. There was a strong inverse relationship between TAPSE/TRV ratio and survival. After multivariate analysis, higher TAPSE/TRV ratios (indicating better RV-PA coupling) were independently associated with lower risk of death in ICU (HR 0.927 [0.872-0.985], p < 0.05). Kaplan-Meier analysis demonstrated higher overall survival in middle and high tertiles compared to low tertiles (log rank p < 0.0001). The prognostic relevance of TAPSE/TRV ratio was strongest in respiratory and sepsis subgroups. Patients with TAPSE/TRV < 5.9 mm (m/s)-1 had a significantly worse prognosis than those with higher TAPSE/TRV ratios.

CONCLUSION

The TAPSE/TRV ratio has prognostic relevance in critically ill patients. The prognostic power may be stronger in respiratory and septic subgroups. Larger prospective studies are needed to investigate the role of TAPSE/TRV in pre-specified subgroups including its role in clinical decision-making.

Speckle tracking for predicting outcomes of balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

Right ventricular (RV) function is a prognostic marker of chronic thromboembolic pulmonary hypertension (CTEPH). We used two-dimensional (2D) speckle-tracking echocardiography (STE) to evaluate the therapeutic effects of balloon pulmonary angioplasty (BPA) in CTEPH patients.

METHODS

A total of 46 CTEPH patients who underwent 2D STE before and after BPA were enrolled in this retrospective study. The following RV functional parameters were measured: tricuspid annular plane systolic excursion (TAPSE), right ventricular fractional area change (RVFAC), RV index of myocardial performance (RIMP), and free wall longitudinal strain (RVFWLS). Satisfactory BPA was defined as mean pulmonary arterial pressure (mPAP) <25 mm Hg or improvement in mPAP > 10 mm Hg after BPA. Patients were divided into two groups according to mPAP values: group I had satisfactory BPA outcomes; group Ⅱ had unsatisfactory BPA outcomes. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to determine the optimal cutoff values and the ability of RVFWLS to predict successful BPA outcomes.

RESULTS

After BPA, SPAP measured by echocardiography (SPAP_echo ) and RIMP decreased, but TAPSE, RVFAC, and RVFWLS increased. Before BPA, group Ⅰ had significantly better RV function than group Ⅱ. Multifactor logistic regression analysis identified RVFWLS as an independent factor associated with satisfactory BPA outcomes. The optimal cutoff value for RVFWLS in predicting satisfactory BPA outcomes was -12.2%.

CONCLUSIONS

Balloon pulmonary angioplasty improves RV function in CTEPH patients. RVFWLS is a valuable noninvasive tool with which to assess the treatment effects of BPA. CTEPH patients with lower RVFWLS may have limited benefit from BPA.

Teamwork using strain imaging in the echocardiographic assessment of right ventricular systolic function: A cardiac magnetic resonance imaging correlation study

AIM

The aim of this study was to investigate whether conventional echocardiographic assessment of right ventricular (RV) systolic function can be improved by the addition of RV strain imaging. Additionally, we also aimed to investigate whether dedicated reading sessions and education can improve echocardiographic interpretation of RV systolic function.

METHODS

Readers of varying expertise (staff echocardiologists, advanced cardiovascular imaging fellows, sonographers) assessed RV systolic function. In session 1, 20 readers graded RV function of 19 cases, using conventional measures. After dedicated education, in session 2, the same cases were reassessed, with the addition of RV strains. In session 3, 18 readers graded RV function of 20 additional cases, incorporating RV strains. Computer simulations were performed to obtain 230 random teams. RV ejection fraction (RVEF) by cardiac magnetic resonance (CMR) was the reference standard.

RESULTS

Correlation between RV GLS and CMR-derived RVEF was moderate: Spearman's rho: 0.70, n = 19, P < 0.001 (first two sessions); 0.55, n = 20, P < 0.05 (third session). Individual readers' assessment moderately correlated with RVEF (Spearman's rho first session: 0.67 ± 0.2; second session: 0.61 ± 0.2; and third session: 0.68 ± 0.09). Team estimates of RV systolic function showed consistently better correlation with RVEF, which were improved further by averaging across all readers. RV strain parameters influenced echocardiographic interpretation, with a net reclassification index of 8.0 ± 3.6% (P = 0.014).

CONCLUSIONS

The RV strain parameters showed moderate correlations with CMR-derived RVEF and appropriately influenced echocardiographic interpretation of RV systolic function. "Wisdom of the crowd" applied by averaging echocardiographic assessments of RV systolic function across teams of echocardiography readers, further improved echocardiographic assessment of RV systolic function.