Association of Apical Longitudinal Rotation with Right Ventricular Performance in Patients with Pulmonary Hypertension: Insights into Overestimation of Tricuspid Annular Plane Systolic Excursion

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 Heart Failure in the Intensive Care Unit: Etiology, Pathogenesis, Diagnosis, and Treatment

Right heart (RH) failure carries a high rate of morbidity and mortality. Patients who present with RH failure often exhibit complex aberrant cardio-pulmonary physiology with varying presentations. The treatment of RH failure almost always requires care and management from an intensivist. Treatment options for RH failure patients continue to evolve rapidly with multiple options available, including different pharmacotherapies and mechanical circulatory support devices that target various components of the RH circulatory system. An understanding of the normal RH circulatory physiology, treatment, and support options for the RH failure patients is necessary for all intensivists to improve outcomes. The purpose of this review is to provide clinical guidance on the diagnosis and management of RH failure within the intensive care unit setting, and to highlight the different pathophysiological manifestations of RH failure, its hemodynamics, and treatment options available at the disposal of the intensivist.

Prognostic value of right ventricular longitudinal strain in patients with secondary mitral regurgitation undergoing transcatheter edge-to-edge mitral valve repair

AIMS

To evaluate the prognostic impact of pre-procedural right ventricular longitudinal strain (RVLS) in patients with secondary mitral regurgitation (SMR) undergoing transcatheter edge-to-edge repair (TEER) in comparison with conventional echocardiographic parameters of RV function.

METHODS AND RESULTS

This is a retrospective study including 142 patients with SMR undergoing TEER at two Italian centres. At 1-year follow-up 45 patients reached the composite endpoint of all-cause death or heart failure hospitalization. The best cut-off value of RV free-wall longitudinal strain (RVFWLS) to predict outcome was -18% [sensitivity 72%, specificity of 71%, area under curve (AUC) 0.78, P < 0.001], whereas the best cut-off value of RV global longitudinal strain (RVGLS) was -15% (sensitivity 56%, specificity 76%, AUC 0.69, P < 0.001). Prognostic performance was suboptimal for tricuspid annular plane systolic excursion, Doppler tissue imaging-derived tricuspid lateral annular systolic velocity and fractional area change (FAC). Cumulative survival free from events was lower in patients with RVFWLS ≥ -18% vs. RVFWLS < -18% (44.0% vs. 85.4%; < 0.001) as well as in patients with RVGLS ≥ -15% vs. RVGLS < -15% (54.9% vs. 81.7%; P < 0.001). At multivariable analysis FAC, RVGLS and RVFWLS were independent predictors of events. The identified cut-off of RVFWLS and RVGLS both resulted independently associated with outcomes.

CONCLUSION

RVLS is a useful and reliable tool to identify patients with SMR undergoing TEER at high risk of mortality and HF hospitalization, on top of other clinical and echocardiographic parameters, with RVFWLS offering the best prognostic performance.

Pathophysiological role of right ventricular function and interventricular functional mismatch in the development of pulmonary edema in acute heart failure

BACKGROUND

Parameters of cardiac function related to the development of pulmonary edema (PE) in acute heart failure (AHF), including right ventricular (RV) function and a mismatch of interventricular function, are not fully elucidated. The aim of this study was to verify the hypothesis that a relatively preserved RV function compared with left ventricular function may be associated with the development of PE by using two-dimensional speckle tracking echocardiography (2DSTE).

METHODS

Hospitalized patients with AHF at 11 institutions were enrolled. PE was defined as lung congestion on chest X-ray with hypoxemia. Patients with systolic blood pressure ≥140 mmHg on admission were defined to have hypertensive AHF. Echocardiographic analyses, including 2DSTE, were performed prior to discharge. The index of mismatch between RV and left ventricular systolic function was assessed by interventricular longitudinal strain difference (IVLSD) which was defined as RV free wall longitudinal strain and left ventricular global longitudinal strain.

RESULTS

Of 610 patients with AHF, 422 (69.2%) had PE. In patients with PE, IVLSD (p = 0.007) and RV fractional area change ratio (p<0.001) was significantly higher than those in patients without PE. In patients with non-hypertensive AHF, RV fractional area change ratio, age, ischemic etiology, and serum brain natriuretic peptide (BNP) levels were independent predictors of PE. In patients with hypertensive AHF, IVLSD, age, and serum BNP levels were independent predictors of PE.

CONCLUSIONS

Preserved RV function might be one of the underlying mechanisms of the development of PE in AHF. Furthermore, interventricular functional mismatch might be related to the development of PE in hypertensive AHF.

Echocardiography in Pulmonary Arterial Hypertension: Comprehensive Evaluation and Technical Considerations

Pulmonary arterial hypertension (PAH) is a rare, progressive disease in which there is a persistent, abnormal increase in pulmonary artery pressure. Symptoms of pulmonary hypertension are nonspecific and mainly associated with progressive right ventricular failure. The diagnosis of PAH is a multistep process and often requires the skillful use of several tests. The gold standard for the diagnosis of PAH is hemodynamic testing. Echocardiography currently plays an important role in the diagnostic algorithm of PAH as it is minimally invasive and readily available. Moreover, many echocardiographic parameters are closely related to pulmonary hemodynamics. It allows assessment of the right heart′s structure and function, estimation of the pressure in the right ventricle, right atrium, and pulmonary trunk, and exclusion of other causes of elevated pulmonary bed pressure. Echocardiographic techniques are constantly evolving, and recently, measurements made using new techniques, especially 3D visualization, have become increasingly important. In echocardiographic assessment, it is crucial to know current guidelines and new reports that organize the methodology and allow standardization of the examination. This review aims to discuss the different echocardiographic techniques used to evaluate patients with PAH.

Prognostic value of right ventricular free wall longitudinal strain in a large cohort of outpatients with left-side heart disease

AIMS

Right ventricular free wall longitudinal strain (RVFWLS) has been proposed as an accurate and sensitive measure of right ventricular function that could integrate other conventional parameters such as tricuspid annulus plane systolic excursion (TAPSE) and fractional area change (FAC%). The aim of the present study was to evaluate the relationship between RVFWLS and outcomes in stable asymptomatic outpatients with left-sided structural heart disease.

METHODS AND RESULTS

We enrolled 458 asymptomatic patients with left-side heart diseases and any ejection fraction who were referred for echocardiography to two Italian centres. The composite endpoint of death for any cause and heart failure hospitalization was used as primary outcome of this analysis. After a mean follow-up of 5.4 ± 1.2 years, 145 patients (31%) reached the combined endpoint. Most of echocardiographic parameters were related to outcomes, including right ventricular functional parameters. Mean value of RVFWLS in our cohort was -21 ± 8% and it was significantly related to the combined endpoint and in multivariable Cox-regression model; when tested with other echocardiographic parameters that were significantly related to outcome at univariate analysis, RVFWLS maintained its independent association with outcome (hazard ratio 0.963, 95% confidence interval 0.948-0.978; P = 0.0001). The best cut-off value of RVFWLS to predict outcome was -22% (area under the curve 0.677; P < 0.001; sensitivity 70%; 65% specificity).

CONCLUSION

RVFWLS may help clinicians to identify patients with left-sided structural heart disease at higher risk for first heart failure hospitalization and death for any cause.

Forgotten No More-The Role of Right Ventricular Dysfunction in Heart Failure with Reduced Ejection Fraction: An Echocardiographic Perspective

During the last decade, studies have raised awareness of the crucial role that the right ventricle plays in various clinical settings, including diseases primarily linked to the left ventricle. The assessment of right ventricular performance with conventional echocardiography is challenging. Novel echocardiographic techniques improve the functional assessment of the right ventricle and they show good correlation with the gold standard represented by cardiac magnetic resonance. This review summarizes the traditional and innovative echocardiographic techniques used in the functional assessment of the right ventricle, focusing on the role of right ventricular dysfunction in heart failure with reduced ejection fraction and providing a perspective on recent evidence from literature.

Tricuspid annular plane systolic excursion is dependent on right ventricular volume in addition to function

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) is an effective parameter for assessing right ventricular (RV) function in echocardiographic studies. The preload dependency of TASPE has not been explored.

METHODS

We retrospectively reviewed 380 cardiac magnetic resonance (CMR) exams. RV ejection fraction (EF) and end-diastolic volume (EDV) were measured from short-axis cine images. TAPSE was measured as the difference of the perpendicular distance of the tricuspid annulus to the RV apex during diastole and systole. RV dysfunction was defined as RVEF <47%. The relationship of TAPSE, RVEF, and indexed RVEDV (RVEDVi) were evaluated. The TAPSE cut-off values derived from CMR were tested in a validation group (n = 46) with an echocardiographic exam performed within 1 month of the CMR.

RESULTS

TAPSE had a good linear correlation with RVEF (r = .69, P < .001). In normal RVEF patients, TAPSE had a positive correlation with RVEDVi (r = .208, P = .014). Receiver operating characteristic analysis revealed a higher TAPSE cut-off value of 2.4 cm in the top normal to mildly dilated RV volume group for identifying RV dysfunction with lower predictive accuracy (sensitivity 80%, specificity 67%, area under the curve = 0.78, P < .001) as compared with 2.0 cm for the normal RV size or moderate to severely dilated RV groups. The higher TAPSE cutoff showed improved sensitivity (73% vs 43%) and Youden index (0.55 vs 0.43) in our validation cohort.

CONCLUSIONS

Tricuspid annular plane systolic excursion not only correlates with RVEF, but also is dependent on RV volume. The cut-off value and predictive accuracy of TAPSE for detecting RV dysfunction vary with different RV volumes.

The Utility of Eccentricity Index as a Measure of the Right Ventricular Function in a Lung Resection Cohort

Context

Right ventricular (RV) dysfunction occurs after lung resection and is associated with postoperative morbidity. Noninvasive evaluation of the RV is challenging, particularly in the postoperative period. A reliable measure of RV function would have value in this population.

Aims

This study compares eccentricity index (EI) obtained by transthoracic echocardiography (TTE) with cardiovascular magnetic resonance (CMR) determined measures of RV function in a lung resection cohort. CMR is the reference method for noninvasive assessment of RV function.

Design and Setting

Prospective observational cohort study at a single tertiary hospital.

Materials and Methods

Twenty-eight patients scheduled for elective lung resection underwent contemporaneous TTE and CMR imaging preoperatively, on postoperative day (POD) 2 and at 2-month. Systolic and diastolic EI was measured offline from anonymized and randomized TTE and CMR images.

Statistical Analysis

Bland-Altman analysis was performed to determine agreement between EI^TTE and EI^CMR. Changes over time and comparison with CMR determined RV ejection fraction (RVEF^CMR) was assessed.

Results

Bland-Altman analysis showed a negligible mean difference between EI^TTE and EI^CMR, but limits of agreement were wide (SD 0.24 and 0.28). There were no significant changes in EI^TTE and EI^CMR over time (P > 0.35). We found no association between EI^TTE with RVEF^CMR at all-time points (P > 0.22). Systolic and diastolic EI^CMR on POD 2 demonstrated moderate association with RVEF^CMR (r = -0.54 and r = -0.59, P ≤ 0.01). At 2-month, only diastolic EI^CMR correlated with RVEF^CMR (r = -0.43, P = 0.03). There were no meaningful associations between EI^TTE and EI^CMR with TTE-derived RV systolic pressure (P > 0.31).

Conclusions

TTE determined EI is not useful as a noninvasive method of assessing RV function following lung resection.

Value of tissue-tracking tricuspid annular plane by speckle-tracking echocardiography for the assessment of right ventricular systolic dysfunction

BACKGROUND

Assessment of right ventricular (RV) function remains challenging because of its complex geometry. Application of speckle-tracking echocardiography (STE) to the tricuspid annulus provides rapid and automated assessment of the midpoint of the tricuspid annular plane displacement (TAD). The aim of this study was to investigate the value of tissue-tracking TAD for the assessment of RV systolic dysfunction.

METHODS

We retrospectively studied 61 patients in whom RV ejection fraction (EF) measured by 3-dimensional echocardiography was performed. STE-derived displacement of the midpoint between the septal and lateral tricuspid annulus and its percentage of RV length at end-diastole (MTAD) were automatically assessed. We performed comparative analyses between the RVEF ≥45% group and the RVEF <45% group in each parameter for the assessment of RV systolic function.

RESULTS

MTAD was successfully assessed in 56 (91.2%). According to receiver operating characteristics analysis, RVEF <45% was best detected by MTAD <14.7% with area under curve (AUC) 0.97, sensitivity 93%, specificity 95%, followed by RV free wall longitudinal strain (AUC 0.86), RV fractional area change (AUC 0.84), tricuspid annular plane systolic excursion (AUC 0.79), and systolic peak velocity of tricuspid annulus (AUC 0.70), although there was no significant difference between MTAD and RV free wall strain (P = 0.14).

CONCLUSION

The present study showed that MTAD was simple index and useful for the assessment of RV systolic dysfunction.

Echocardiography during preload stress for evaluation of right ventricular contractile reserve and exercise capacity in pulmonary hypertension

OBJECTIVES

Pulmonary hypertension (PH) is characterized by marked and sustained elevation of pulmonary vascular resistance and pulmonary artery pressure, and subsequent right-sided heart failure. Right ventricular (RV) function and exercise capacity have been recognized as important prognostic factors for PH. Our aim was to investigate RV contractile reserve and exercise capacity during a leg-positive pressure (LPP) maneuver.

METHODS

The study population comprised 43 PH patients and 17 normal controls. All patients underwent echocardiography at rest and during LPP stress. Exercise capacity was assessed by 6-minute walk distance for PH patients. RV relative wall thickness was calculated from dividing by RV free wall thickness by basal RV linear dimensions at end-diastole. RV function was calculated by averaging peak speckle-tracking longitudinal strain from the RV free wall. RV contractile reserve was assessed as the difference in RV free wall strain at rest and during LPP stress. Changes in left ventricular stroke volume (ΔSV) during LPP stress were also calculated.

RESULTS

ΔSV and RV contractile reserve of PH patients were significantly lower than of controls (3.6 ± 6.0 mL vs 8.5 ± 2.3 mL, and 8.2 ± 11.9% vs 14.5 ± 6.6%; both P < 0.01). RV contractile reserve of PH patients with ΔSV <3.3 mL was significantly lower than of PH patients with ΔSV >3.3 mL (3.9 ± 13.2% vs 12.3 ± 8.9%; P = 0.02). ΔSV had also significant correlation with 6-minute walk distance (r = 0.42, P = 0.006). Multivariate regression analysis showed that RV relative wall thickness was an independent determinant parameter of ΔSV during LPP stress for PH patients (β = 3.2, P = 0.003).

CONCLUSIONS

Preload stress echocardiography in response to LPP maneuver, a noninvasive and easy-to-use procedure for routine clinical use, proved to be useful for the assessment of RV contractile reserve and exercise capacity of PH patients.

A Computational Cardiac Model for the Adaptation to Pulmonary Arterial Hypertension in the Rat

Pulmonary arterial hypertension (PAH) imposes pressure overload on the right ventricle (RV), leading to RV enlargement via the growth of cardiac myocytes and remodeling of the collagen fiber architecture. The effects of these alterations on the functional behavior of the right ventricular free wall (RVFW) and organ-level cardiac function remain largely unexplored. Computational heart models in the rat (RHMs) of the normal and hypertensive states can be quite valuable in simulating the effects of PAH on cardiac function to gain insights into the pathophysiology of underlying myocardium remodeling. We thus developed high-fidelity biventricular finite element RHMs for the normal and post-PAH hypertensive states using extensive experimental data collected from rat hearts. We then applied the RHM to investigate the transmural nature of RVFW remodeling and its connection to wall stress elevation under PAH. We found a strong correlation between the longitudinally-dominated fiber-level adaptation of the RVFW and the transmural alterations of relevant wall stress components. We further conducted several numerical experiments to gain new insights on how the RV responds both normally and in the post-PAH state. We found that the effect of pressure overload alone on the increased contractility of the RV is comparable to the effects of changes in the RV geometry and stiffness. Furthermore, our RHMs provided fresh perspectives on long-standing questions of the functional role of the interventricular septum in RV function. Specifically, we demonstrated that an inaccurate identification of the mechanical adaptation of the septum can lead to a significant underestimation of RVFW contractility in the post-PAH state. These findings show how integrated experimental-computational models can facilitate a more comprehensive understanding of the cardiac remodeling events during PAH.

Usefulness of scoring right ventricular function for assessment of prognostic factors in patients with chronic thromboembolic pulmonary hypertension

Right ventricular (RV) function is associated with prognosis in chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to establish an RV dysfunction score using RV echocardiographic parameters to clarify the clinical characteristics in patients with CTEPH and to compare RV dysfunction score with parameters such as World Health Organization (WHO) functional class, hemodynamics, exercise capacity, and plasma BNP level. We enrolled 35 inpatients with CTEPH (mean age, 62 ± 15 years, 15 males). We constructed ‘an RV dysfunction score’ calculated as the summation of each point awarded for the presence of four parameters: tricuspid annular plane systolic excursion (TAPSE) < 16 mm, 1 point; tissue Doppler-derived tricuspid lateral annular systolic velocity (S′) < 10 cm/s, 1 point; right ventricular fractional area change (RVFAC) < 35%, 1 point; and right ventricular myocardial performance index (RV-MPI) > 0.4, 1 point. TAPSE, S′, RVFAC, and RV-MPI was 18.7 ± 4.8 mm, 11.9 ± 3.1 cm/s, 33.5 ± 13.9%, and 0.39 ± 0.2, respectively. The RV dysfunction score was associated with symptom [WHO functional class (p = 0.026)], hemodynamics [mean PAP (p = 0.01), cardiac index (p = 0.009), pulmonary vascular resistance (p = 0.001), and SvO₂ (p = 0.039)], exercise capacity [6-min walk distance (p = 0.046), peakVO₂ (p = 0.016), and VE/VCO₂ slope (p = 0.031)], and plasma BNP level (p = 0.005). This RV dysfunction score using the four RV echocardiographic parameters could be a simple and useful scoring system to evaluate prognostic factors in patients with CTEPH.

Novel echocardiographic prognostic markers for cardiac tamponade in patients with large malignant pericardial effusions: A paradigm shift from flow to tissue imaging

BACKGROUND

With this study, we sought to investigate the prognostic value of echocardiographic tissue imaging markers in predicting tamponade among patients with large malignant pericardial effusion compared to routinely used echocardiographic signs.

METHODS

A total of 96 consecutive patients with large malignant pericardial effusion, not in clinical cardiac tamponade, underwent an echocardiographic examination and were prospectively assessed for 1 month. Clinically evident cardiac tamponade was considered as the study endpoint. The prognostic performance of tricuspid valve annular plane systolic excursion (TAPSE) and peak systolic annular velocity at the lateral margin of the tricuspid valve annulus (S_TV ) was assessed and compared to routinely used imaging signs.

RESULTS

During follow-up, 37 patients (39%) developed clinically evident cardiac tamponade. TAPSE (area under the curve [AUC] 0.958) and S_TV (AUC 0.948) had excellent predictive accuracy for tamponade. Multivariate analysis showed that TAPSE (Hazard ratio [HR] 3.03; 95% CI 1.60-5.73, P=.001) and S_TV (HR 1.17; 95% CI 1.05-1.29, P=.005) remained independent significant predictors of cardiac tamponade. Reclassification analysis and decision curve analysis showed additive prognostic value and adjunct clinical benefit of these markers when added to a recently published triage pericardiocentesis score.

CONCLUSION

Echocardiographic tissue imaging markers such as TAPSE and S_TV are characterized by an excellent prognostic ability for development of cardiac tamponade and better prognostic value compared to routine echocardiographic signs in patients with large malignant pericardial effusion. Incorporating these markers to a recent triage pericardiocentesis score resulted in additional prognostic value and increased clinical benefit.

Tricuspid annular plane systolic excursion in dogs with myxomatous mitral valve disease with and without pulmonary hypertension

OBJECTIVES

To evaluate tricuspid annular plane systolic excursion (TAPSE) in dogs with myxomatous mitral valve disease (MMVD) with or without pulmonary hypertension (PH) and to study the correlations with clinical and echocardiographic parameters.

ANIMALS

The study population included 99 dogs with MMVD and tricuspid regurgitation.

METHODS

This is a prospective clinical study. All dogs received a transthoracic echocardiographic evaluation, including 2D, M-mode, echo-Doppler, and tissue Doppler measurements. The TAPSE was measured from the left apical four-chamber view and normalized for the effect of body weight (nTAPSE). The dogs were grouped according to the severity of MMVD (American College of Veterinary Internal Medicine guidelines) and presence/absence and severity of PH. Significant differences between TAPSE or nTAPSE and echocardiographic parameters were analyzed among the MMVD and PH severity groups. Correlations between TAPSE or nTAPSE and echocardiographic parameters were calculated.

RESULTS

Tricuspid annular plane systolic excursion or nTAPSE were not significantly different among dogs of the MMVD or PH severity groups. Significant correlations were obtained between TAPSE and body weight, left ventricular and atrial dimensions, early diastolic septal and early diastolic and systolic tricuspid annulus velocity (p<0.001); nTAPSE was significantly correlated with normalized end-diastolic left ventricular dimension and fractional shortening (p<0.001).

CONCLUSIONS

The results show that neither TAPSE nor nTAPSE are reduced in dogs with MMVD with or without PH. It remains unclear if the right ventricle function is not reduced or if a reduced right ventricle function is masked by the contraction of the left ventricle through ventricular interdependence.

Normal Reference Values and z Scores of the Pulmonary Artery Acceleration Time in Children and Its Importance for the Assessment of Pulmonary Hypertension

BACKGROUND

Pulsed-wave Doppler determination of the pulmonary artery acceleration time (PAAT) as a surrogate for pulmonary artery pressure was found to be of clinical value for assessment of pulmonary hypertension (PH) with studies to date exclusively performed in adults. This study aims to provide representative, normal reference values for PAAT in children of all ages. Moreover, we validated abnormal PAAT values in 54 children with PH.

METHODS AND RESULTS

We conducted a prospective echocardiographic study in 756 healthy children (aged 1 day to 18 years) and in 54 children with PH. Possible associations of age, body length, body weight, body surface area, and heart rate on PAAT were investigated. The PAAT correlated positively with age (r=0.848), body length (r=0.871), body surface area (r=0.856), and body weight (r=0.825) and negatively with heart rate (r=-0.906). PAAT increased with age (neonates: median: 81 ms, range: 53-104; 18th year of life: median: 151 ms, range: 107-187). Receiver operating characteristic analysis for detecting PH patients using age-specific z scores showed an excellent performance of PAAT (P<0.001; area under the curve, 0.98; 95% confidence interval, 0.97-0.99) with a best cutoff score according to Youden index of -1.565 (sensitivity: 92%, specificity: 96%). PAAT values of PH patients negatively correlated (ρ=-0.497) with pulmonary vascular resistance.

CONCLUSIONS

The PAAT normal reference values and z scores we provide here will be useful to identify children with a shortened PAAT. Abnormal PAAT values with scores <-2 were predictive of PH.

Regional right ventricular remodeling and function in children with idiopathic pulmonary arterial hypertension vs those with pulmonary valve stenosis: Insights into mechanics of right ventricular dysfunction

BACKGROUND

Right ventricular (RV) pressure overload in the context of pulmonary stenosis (PS) has a much better prognosis than in the context of idiopathic pulmonary arterial hypertension (iPAH), which may be related to differences in global and regional RV remodeling and systolic function. We compared RV mechanics in children with PS to those with iPAH, aiming to identify mechanisms and markers of RV dysfunction.

METHODS

Eighteen controls, 18 iPAH and 16 PS patients were retrospectively studied. Age, BSA, and sex distribution were comparable. Two-dimensional echocardiography, blood flow and tissue Doppler, and longitudinal RV deformation were analyzed. ANCOVA-including RV systolic pressure (RVSP) and length as covariates-was used to compare patient groups.

RESULTS

RV systolic pressure was higher in iPAH vs PS (96.8±25.4 vs 75.4±18.9 mm Hg, P=.011). Compared to controls, PS patients showed mild dilation (P<.01) and decreased longitudinal deformation (P<.001) at the RV apex. Compared to both PS and controls, iPAH patients showed marked spherical RV dilation (P<.001), reduced global, RV free wall and septal longitudinal deformation (iPAH -22.07%±4.35% vs controls -28.18%±1.69%; -9.98%±4.30% vs -17.45%±2.52%; P<.001) and RV postsystolic shortening (P<.001). RV transverse shortening (radial performance) was increased in PS (31.75%±10.35%; P<.001) but reduced in iPAH (-1.62%±11.11% vs controls 12.00%±7.74%; P<.001).

CONCLUSION

Children with iPAH demonstrate adverse global and regional RV remodeling and mechanics compared to those with PS. Mechanisms of RV systolic dysfunction in iPAH include decreased longitudinal deformation, decreased or absent transverse shortening, and postsystolic shortening. These markers may be useful to identify children at risk of RV failure.

Right ventricular relative wall thickness as a predictor of outcomes and of right ventricular reverse remodeling for patients with pulmonary hypertension

Mid-term right ventricular (RV) reverse remodeling after treatment in patients with pulmonary hypertension (PH) is associated with long-term outcome as well as baseline RV remodeling. However, baseline factors influencing mid-term RV reverse remodeling after treatment and its prognostic capability remain unclear. We studied 54 PH patients. Mid-term RV remodeling was assessed in terms of the RV area, which was traced planimetrically at the end-systole (RVESA). RV reverse remodeling was defined as a relative decrease in the RVESA of at least 15% at 10.2 ± 9.4 months after treatment. Long-term follow-up was 5 years. Adverse events occurred in ten patients (19%) and mid-term RV reverse remodeling after treatment was observed in 37 (69%). Patients with mid-term RV reverse remodeling had more favorable long-term outcomes than those without (log-rank: p = 0.01). Multivariate logistic regression analysis showed that RV relative wall thickness (RV-RWT), as calculated as RV free-wall thickness/RV basal linear dimension at end-diastole, was an independent predictor of mid-term RV reverse remodeling (OR 1.334; 95% CI, 1.039-1.713; p = 0.03). Moreover, patients with RV-RWT ≥0.21 showed better long-term outcomes than did those without (log-rank p = 0.03), while those with RV-RWT ≥0.21 and mid-term RV reverse remodeling had the best long-term outcomes. Patients with RV-RWT <0.21 and without mid-term RV reverse remodeling, on the other hand, had worse long-term outcomes than other sub-groups. In conclusions, RV-RWT could predict mid-term RV reverse remodeling after treatment in PH patients, and was associated with long-term outcomes. Our finding may have clinical implications for better management of PH patients.