Follow-Up of Pulmonary Hypertension With Echocardiography

Right Atrial Strain in Pediatric Pulmonary Hypertension-A Prospective Observational Study

Right ventricular (RV) afterload due to elevated pulmonary arterial (PA) pressure in pulmonary hypertension (PH) causes long-term right atrial (RA) remodeling and dysfunction. RA function has been shown to correlate with PA pressures and outcome in both adult and pediatric patients with PH. We studied the role of RA strain in estimating PA pressures in congenital heart disease (CHD)-associated PH. Children below 12 years undergoing elective repair of CHD with left-to-right shunts and echocardiographic evidence of PH were included. RA reservoir, conduit and contractile strain along with conventional measures of RV function and PA pressure were measured using transthoracic echocardiography after induction of anaesthesia. Pre-and post-repair invasive PA pressures were measured after surgical exposure. 51 children with a median age of 24 months (range 4-144 months) were included, most of whom were undergoing VSD closure. Contractile RA strain showed good correlation with pre-repair systolic PA pressure in mmHg (r = 0.59, 95%CI 0.37-0.75) or expressed as a percentage of SBP (r = 0.67, 95%CI 0.49-0.80). It also predicted persistent postoperative PH as well as pre-repair pulmonary artery acceleration time and right ventricular systolic pressure measured from tricuspid regurgitation jet. The trends of correlation observed suggest a possible prognostic role of RA strain in ACHD with PH and potential utility in its echocardiographic assessment. The observed findings merit deeper evaluation in larger cohorts.

The Role of Echocardiography in the Diagnosis and Prognosis of Pulmonary Hypertension

The right heart catheterisation constitutes the gold standard for pulmonary hypertension (PH) diagnosis. However, echocardiography remains a reliable, non-invasive, inexpensive, convenient, and easily reproducible modality not only for the preliminary screening of PH but also for PH prognosis. The aim of this review is to describe a cluster of echocardiographic parameters for the detection and prognosis of PH and analyse the challenges of echocardiography implementation in patients with suspected or established PH. The most important echocardiographic index is the calculation of pulmonary arterial systolic pressure (PASP) through the tricuspid regurgitation (TR). It has shown high correlation with invasive measurement of pulmonary pressure, but several drawbacks have questioned its accuracy. Besides this, the right ventricular outflow track acceleration time (RVOT-AT) has been proposed for PH diagnosis. A plethora of echocardiographic indices: right atrial area, pericardial effusion, the tricuspid annular plane systolic excursion (TAPSE), the TAPSE/PASP ratio, tricuspid annular systolic velocity (s'), can reflect the severity and prognosis of PH. Recent advances in echocardiography with 3-dimensional right ventricular (RV) ejection fraction, RV free wall strain and right atrial strain may further assist the prognosis of PH.

Idiopathic Pulmonary Arterial Hypertension in Paediatrics Represents Still a Serious Challenge: A Case Series Study

Introduction: Paediatric pulmonary hypertension (PH) represents a heterogeneous illness that is responsible for high morbidity and mortality if left without treatment. Idiopathic pulmonary arterial hypertension (IPAH) is a subtype of PAH rarely seen in paediatrics. Limited long-term data are available. Methods: Over a period of 20 years, 10 paediatric patients were enrolled at two tertiary centres. Their clinical, echocardiographic, and right heart catheterisation (RHC) features and outcome were evaluated. Results: The mean age at first diagnosis was 5.7 ± 5.7 years. The age at the last follow-up was 12.4 ± 6.1 years. The average follow-up was 6.6 ± 0.8 years. There was a female prevalence of 60% (p < 0.05) in this case series. Regarding the NYHA functional class, 80% of IPAH subjects were in class III or IV. The mean saturation was 91 ± 5%. In this regard, 70% of the patients were on a combination of three drugs, with sildenafil (90%) included. On echocardiography, longitudinal right ventricular contractility (TAPSE) was slightly reduced (13.4 ± 2.6 mm), whilst RVSP was severely elevated (101 ± 19 mmHg). The RHC data showed that mPAP was 61.8 ± 23.1 mmHg (p = 0.0017 with RVSP on echocardiography), mRAP was 10.7 ± 3.8 mmHg, CI was 2.6 ± 1 L·min−1·m−2, PVRi was 16.8 ± 12.6 WU·m2, and SVO2 was 63.6 ± 14.8%. Regarding the outcome, two male IPAH patients (20%) died, and 50% underwent lung transplant or were on transplant assessment or already on the waiting list for lung transplantation. One patient underwent a ductus arteriosus stenting (reverse Potts shunt) and another underwent atrial septostomy and stenting. Conclusions: Notwithstanding the progress in medical therapy, IPAH continues to represent a serious challenge, particularly in the paediatric population, with the need for lung transplantation and significant mortality.

Imaging in Pulmonary Vascular Disease-Understanding Right Ventricle-Pulmonary Artery Coupling

The right ventricle (RV) and pulmonary arterial (PA) tree are inextricably linked, continually transferring energy back and forth in a process known as RV-PA coupling. Healthy organisms maintain this relationship in optimal balance by modulating RV contractility, pulmonary vascular resistance, and compliance to sustain RV-PA coupling through life's many physiologic challenges. Early in states of adaptation to cardiovascular disease-for example, in diastolic heart failure-RV-PA coupling is maintained via a multitude of cellular and mechanical transformations. However, with disease progression, these compensatory mechanisms fail and become maladaptive, leading to the often-fatal state of "uncoupling." Noninvasive imaging modalities, including echocardiography, magnetic resonance imaging, and computed tomography, allow us deeper insight into the state of coupling for an individual patient, providing for prognostication and potential intervention before uncoupling occurs. In this review, we discuss the physiologic foundations of RV-PA coupling, elaborate on the imaging techniques to qualify and quantify it, and correlate these fundamental principles with clinical scenarios in health and disease. © 2022 American Physiological Society. Compr Physiol 12: 1-26, 2022.

A framework of deep learning networks provides expert-level accuracy for the detection and prognostication of pulmonary arterial hypertension

AIMS

To test the hypothesis that deep learning (DL) networks reliably detect pulmonary arterial hypertension (PAH) and provide prognostic information.

METHODS AND RESULTS

Consecutive patients with PAH, right ventricular (RV) dilation (without PAH), and normal controls were included. An ensemble of deep convolutional networks incorporating echocardiographic views and estimated RV systolic pressure (RVSP) was trained to detect (invasively confirmed) PAH. In addition, DL-networks were trained to segment cardiac chambers and extracted geometric information throughout the cardiac cycle. The ability of DL parameters to predict all-cause mortality was assessed using Cox-proportional hazard analyses. Overall, 450 PAH patients, 308 patients with RV dilatation (201 with tetralogy of Fallot and 107 with atrial septal defects) and 67 normal controls were included. The DL algorithm achieved an accuracy and sensitivity of detecting PAH on a per patient basis of 97.6 and 100%, respectively. On univariable analysis, automatically determined right atrial area, RV area, RV fractional area change, RV inflow diameter and left ventricular eccentricity index (P < 0.001 for all) were significantly related to mortality. On multivariable analysis DL-based RV fractional area change (P < 0.001) and right atrial area (P = 0.003) emerged as independent predictors of outcome. Statistically, DL parameters were non-inferior to measures obtained manually by expert echocardiographers in predicting prognosis.

CONCLUSION

The study highlights the utility of DL algorithms in detecting PAH on routine echocardiograms irrespective of RV dilatation. The algorithms outperform conventional echocardiographic evaluation and provide prognostic information at expert-level. Therefore, DL methods may allow for improved screening and optimized management of PAH.

Time-Velocity Integral of Left Ventricular Outflow Tract Predicts Worse Long-Term Survival in Pulmonary Arterial Hypertension

BACKGROUND

The time-velocity integral of the left ventricular outflow tract (TVI_LVOT) has been demonstrated to correlate with heart failure hospitalization and mortality, but the association of TVI_LVOT with the severity and prognosis of pulmonary arterial hypertension (PAH) has not been evaluated.

OBJECTIVES

The aim of this study was to investigate the predictive value of baseline TVI_LVOT in PAH.

METHODS

A total of 225 consecutive patients with a diagnosis of incident PAH were prospectively studied and echocardiology-derived TVI_LVOT was measured at enrollment followed by right heart catheterization examination within 48 hours. Cox proportional hazards analysis was performed to assess the association between baseline variables and mortality.

RESULTS

During a median follow-up period of 33.8 months, 44 patients died of cardiovascular events. Baseline TVI_LVOT was significantly lower in the nonsurvivors compared with the survivors (P < 0.001). Baseline TVI_LVOT was positively correlated with stroke volume obtained by right heart catheterization (r = 0.709; P < 0.001), and inversely correlated with N-terminal pro-B-type natriuretic peptide (r = -0.533; P < 0.001), pulmonary vascular resistance (r = -0.423; P < 0.001). Multivariate analysis showed that baseline TVI_LVOT (hazard ratio: 0.856; 95% CI: 0.780-0.941; P = 0.001) was an independent predictor of cardiovascular mortality in PAH. Patients with a baseline TVI_LVOT <17.1 cm (median value) had a significantly worse survival than those with a baseline TVI_LVOT ≥17.1 cm (P < 0.001).

CONCLUSIONS

The findings of this study suggest that noninvasive TVI_LVOT provides a practical method to assess the severity and predict long-term outcome of PAH.

Accuracy of echocardiographic estimations of right heart pressures in adult heart transplant recipients

BACKGROUND

Accurate assessment of right atrial pressure (RAP) and pulmonary artery systolic pressure (PASP) is critical in the management of heart transplant recipients. The accuracy of echocardiography in estimating these pressures has been debated.

OBJECTIVE

To assess the correlation and agreement between echocardiographic estimations of right heart pressures with those of respective invasive hemodynamic measurements by right heart catheterization (RHC) in adult heart transplant recipients.

METHODS

This is a prospective evaluation of 84 unique measurements from heart transplant recipients who underwent RHC followed by standard echocardiographic evaluation within 159 ± 64 min with no intervening medication changes. The relationship between noninvasive pressure estimations and invasive hemodynamic measurements was examined.

RESULTS

Mean RAP was 7 ± 5 mmHg and mean PASP was 33 ± 8 mmHg by RHC. There was no significant correlation between echocardiographic estimation of RAP and invasive RAP (Spearman's rho = -0.05, p = .7), and no significant agreement between these two variables (weighted kappa = -0.1). There was a modest correlation between echocardiographic estimation of PASP and invasive PASP (r = .39, p = .002). Bland-Altman analysis showed a mean bias of 2.1 ± 9 mmHg (limits of agreement = -15 to 20 mmHg).

CONCLUSION

In heart transplant recipients, there is no significant correlation or agreement between echocardiographic RAP estimation and invasively determined RAP. Noninvasive PASP estimation correlates significantly but modestly with invasively measured PASP. Further refinement of echocardiographic methods for assessment of RAP is warranted in this unique patient population.

Predictors of Maternal Death Among Women With Pulmonary Hypertension in China From 2012 to 2020: A Retrospective Single-Center Study

Background

Previous studies have suggested that pregnant women with pulmonary hypertension (PH) have high maternal mortality. However, indexes or factors that can predict maternal death are lacking.

Methods

We retrospectively reviewed pregnant women with PH admitted for delivery from 2012 to 2020 and followed them for over 6 months. The patients were divided into two groups according to 10-day survival status after delivery. Predictive models and predictors for maternal death were identified using four machine learning algorithms: naïve Bayes, random forest, gradient boosting decision tree (GBDT), and support vector machine.

Results

A total of 299 patients were included. The most frequent PH classifications were Group 1 PH (73.9%) and Group 2 PH (23.7%). The mortality within 10 days after delivery was 9.4% and higher in Group 1 PH than in the other PH groups (11.7 vs. 2.6%, P = 0.016). We identified 17 predictors, each with a P-value < 0.05 by univariable analysis, that were associated with an increased risk of death, and the most notable were pulmonary artery systolic pressure (PASP), platelet count, red cell distribution width, N-terminal brain natriuretic peptide (NT-proBNP), and albumin (all P < 0.01). Four prediction models were established using the candidate variables, and the GBDT model showed the best performance (F1-score = 66.7%, area under the curve = 0.93). Feature importance showed that the three most important predictors were NT-proBNP, PASP, and albumin.

Conclusion

Mortality remained high, particularly in Group 1 PH. Our study shows that NT-proBNP, PASP, and albumin are the most important predictors of maternal death in the GBDT model. These findings may help clinicians provide better advice regarding fertility for women with PH.

The Role of Conjunctival Microvasculation Combined with Echocardiography in Evaluating Pulmonary Arterial Hypertension in Systemic Lupus Erythematosus

Objective

To explore the role of conjunctival microvasculation combined with echocardiography in evaluating the prognosis of pulmonary arterial hypertension in systemic lupus erythematosus (SLE-PAH).

Methods

We prospectively compared the conjunctival microvascular changes in 17 SLE-PAH patients and 34 SLE patients without PAH in our hospital from January 2020 to December 2020, and we observed the characteristics of conjunctival microvascular changes in SLE-PAH patients. We analyzed the correlation between the corresponding conjunctival microvascular changes and cardiopulmonary function and evaluated the predictive value of the vessel density (VD) and the microvascular flow index (MFI) of conjunctival microvasculation combined with echocardiography in SLE-PAH.

Results

Compared with SLE patients without PAH, the ischemic areas in conjunctival microvasculation were significantly increased in SLE-PAH patients. The VD and MFI of conjunctival microvasculation are significantly correlated with N-terminal prohormone of brain natriuretic peptide and 6-minute walking distance. Combined with the VD and MFI, it can improve the accuracy of echocardiography in assessing the risk of death due to SLE-PAH (94.1% vs. 82.2%).

Conclusion

The ischemic area, VD, and MFI of conjunctival microvasculation in SLE-PAH patients can indicate the occurrence of severe SLE-PAH and improve the accuracy of echocardiography in evaluating the prognosis of SLE-PAH.

Clinical application of pulmonary vascular resistance in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension is a type of malignant pulmonary vascular disease, which is mainly caused by the increase of pulmonary vascular resistance due to the pathological changes of the pulmonary arteriole itself, which eventually leads to right heart failure and death. As one of the diagnostic indicators of hemodynamics, pulmonary vascular resistance plays an irreplaceable role in the pathophysiology, diagnosis and treatment of pulmonary arterial hypertension. It provides more references for the evaluation of pulmonary arterial hypertension patients. This article summarizes the clinical application of pulmonary vascular resistance in patients with pulmonary arterial hypertension.

Evaluation of Effect of Curcumin on Psychological State of Patients with Pulmonary Hypertension by Magnetic Resonance Image under Deep Learning

This research aimed to evaluate the right ventricular segmentation ability of magnetic resonance imaging (MRI) images based on deep learning and evaluate the influence of curcumin (Cur) on the psychological state of patients with pulmonary hypertension (PH). The heart MRI images were detected based on the You Only Look Once (YOLO) algorithm, and then the MRI image right ventricle segmentation algorithm was established based on the convolutional neural network (CNN) algorithm. The segmentation effect of the right ventricle in cardiac MRI images was evaluated regarding intersection-over-union (IOU), Dice coefficient, accuracy, and Jaccard coefficient. 30 cases of PH patients were taken as the research object. According to different treatments, they were rolled into control group (conventional treatment) and Cur group (conventional treatment + Cur), with 15 cases in each group. Changes in the scores of the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) of the two groups of patients before and after treatment were analyzed. It was found that the average IOU of the heart target detection frame of the MRI image and the true bounding box before correction was 0.7023, and the IOU after correction was 0.9016. The Loss of the MRI image processed by the CNN algorithm was 0.05, which was greatly smaller than those processed by other algorithms. The Dice coefficient, Jaccard coefficient, and accuracy of the MRI image processed by CNN were 0.89, 0.881, and 0.994, respectively. The MRI images of PH patients showed that the anterior wall of the right ventricle was notably thickened, and the main pulmonary artery was greatly widened. After treatment, the SAR and SDS scores of the two groups were lower than those before treatment (P < 0.05), and the SAR and SDS scores of the curcumin group were lower than those of the control group (P < 0.05). To sum up, the right ventricular segmentation ability of MRI images based on deep learning was improved, and Cur can remarkably alleviate the psychological state of PH patients, which provided a reference for the diagnosis and treatment for PH patients.

Echocardiographic Prognosis Relevance of Attenuated Right Heart Remodeling in Idiopathic Pulmonary Arterial Hypertension

Background: Right ventricular (RV) function is a great determination of the fate in patients with pulmonary arterial hypertension (PAH). Monitoring RV structure back to normal or improvement should be useful for evaluation of RV function. The aims of this study were to assess the prognostic relevance of changed right heart (RH) dimensions by echocardiography and attenuated RH remodeling (ARHR) in idiopathic PAH (IPAH).

Methods: We retrospectively analyzed 232 consecutive adult IPAH patients at baseline assessment and included RH catheterization and echocardiography. ARHR at the mean 20 ± 12 months' follow-up was defined by a decreased right atrium area, RV mid-diameter, and left ventricular end-diastolic eccentricity index. The follow-up end point was all-cause mortality.

Results: At mean 20 ± 12 months' follow-up, 33 of 232 patients (14.2%) presented with ARHR. The remaining 199 surviving patients were monitored for another 25 ± 20 months. At the end of follow-up, the survival rates at 1, 3, and 5 years were 89, 89, and 68% in patients with ARHR, respectively, and 84, 65 and 41% in patients without ARHR (log-rank p = 0.01). ARHR was an independent prognostic factor for mortality. Besides, ARHR was available to further stratify patients' risk assessment through the French PAH non-invasive-risk criteria.

Conclusions: Echocardiographic ARHR is an independent determinant of prognosis in IPAH at long-term follow-up. ARHR might be a useful tool to indicate the RV morphologic and functional improvement associated with better prognostic likelihood.

MR 4D flow-based mean pulmonary arterial pressure tracking in pulmonary hypertension

Objectives

Longitudinal hemodynamic follow-up is important in the management of pulmonary hypertension (PH). This study aimed to evaluate the potential of MR 4-dimensional (4D) flow imaging to predict changes in the mean pulmonary arterial pressure (mPAP) during serial investigations.

Methods

Forty-four adult patients with PH or at risk of developing PH repeatedly underwent routine right heart catheterization (RHC) and near-term MR 4D flow imaging of the main pulmonary artery. The duration of vortical blood flow along the main pulmonary artery was evaluated from MR 4D velocity fields using prototype software and converted to an MR 4D flow imaging-based mPAP estimate (mPAP_MR) by a previously established model. The relationship of differences between RHC-derived baseline and follow-up mPAP values (ΔmPAP) to corresponding differences in mPAP_MR (ΔmPAP_MR) was analyzed by means of regression and Bland-Altman analysis; the diagnostic performance of ΔmPAP_MR in predicting mPAP increases or decreases was investigated by ROC analysis.

Results

Areas under the curve for the prediction of mPAP increases and decreases were 0.92 and 0.93, respectively. With the natural cutoff ΔmPAP_MR = 0 mmHg, mPAP increases (decreases) were predicted with an accuracy, sensitivity, and specificity of 91% (91%), 85% (89%), and 94% (92%), respectively. For patients in whom 4D flow allowed a point estimate of mPAP (mPAP > 16 mmHg), ΔmPAP_MR correlated strongly with ΔmPAP (r = 0.91) and estimated ΔmPAP bias-free with a standard deviation of 5.1 mmHg.

Conclusions

MR 4D flow imaging allows accurate non-invasive prediction and quantification of mPAP changes in adult patients with PH or at risk of developing PH.

Trial registration

ClinicalTrials.gov identifier: NCT00575692 and NCT01725763

Key Points

• MR 4D flow imaging allows accurate non-invasive prediction of mean pulmonary arterial pressure increases and decreases in adult patients with or at risk of developing pulmonary hypertension.

• In adult patients with mean pulmonary arterial pressure > 16 mmHg, MR 4D flow imaging allows estimation of longitudinal mean pulmonary arterial pressure changes without bias with a standard deviation of 5.1 mmHg.

Hepatic and splenic sonographic and sonoelastographic findings in pulmonary arterial hypertension

Purpose

The aim of this study was to evaluate the associations of sonographic and sonoelastographic parameters with clinical cardiac parameters, as well as to assess their value in predicting survival in patients with pulmonary arterial hypertension (PAH).

Methods

Thirty-six patients with PAH and normal liver function were prospectively enrolled in this prospective study along with 26 healthy controls, all of whom underwent ultrasound and point shear wave elastography examinations. Additionally, the portal vein pulsatility index (PVPI), inferior vena cava collapsibility index, and clinical cardiac variables were obtained in PAH patients. The values of hepatic (LV_s) and splenic shear wave velocity (SV_s) were compared between PAH patients and controls. The relationships between all sonographic and clinical parameters in the PAH patients were analyzed. Furthermore, their prognostic value in predicting survival was investigated.

Results

LV_s values in PAH patients (median, 1.62 m/s) were significantly higher than in controls (median, 0.99 m/s), while no significant difference was observed in SV_s values. Patients with higher grades of tricuspid regurgitation (TR) had significantly different values of PVPI (P=0.010) and sonoelastographic parameters (P<0.001 for LV_s and P=0.004 for SV_s) compared to those with less severe TR. Tricuspid annular plane systolic excursion values were the only investigated parameter found to be associated with survival (hazard ratio, 0.814; 95% confidence interval, 0.694 to 0.954; P=0.011).

Conclusion

Our results demonstrated a direct association between cardiac congestion (i.e., the severity of TR) and liver stiffness, which should be kept in mind during the assessment of fibrosis in patients with PAH.

Echocardiographic markers of pulmonary hemodynamics and right ventricular hypertrophy in rat models of pulmonary hypertension

Echocardiography is the gold standard non-invasive technique to diagnose pulmonary hypertension. It is also an important modality used to monitor disease progression and response to treatment in patients with pulmonary hypertension. Surprisingly, only few studies have been conducted to validate and standardize echocardiographic parameters in experimental animal models of pulmonary hypertension. We sought to define cut-off values for both invasive and non-invasive measures of pulmonary hemodynamics and right ventricular hypertrophy that would reliably diagnose pulmonary hypertension in three different rat models. The study was designed in two phases: (1) a derivation phase to establish the cut-off values for invasive measures of right ventricular systolic pressure, Fulton's index (right ventricular weight/left ventricle + septum weight), right ventricular to body weight ratio, and non-invasive echocardiographic measures of pulmonary arterial acceleration time, pulmonary arterial acceleration time to ejection time ratio and right ventricular wall thickness in diastole in the hypoxic and monocrotaline rat models of pulmonary hypertension and (2) a validation phase to test the performance of the cut-off values in predicting pulmonary hypertension in an independent cohort of rats with Sugen/hypoxia-induced pulmonary hypertension. Our study demonstrates that right ventricular systolic pressure ≥35.5 mmHg and Fulton's Index ≥0.34 are highly sensitive (>94%) and specific (>91%) cut-offs to distinguish animals with pulmonary hypertension from controls. When pulmonary arterial acceleration time/ejection time and right ventricular wall thickness in diastole were both measured, a result of either pulmonary arterial acceleration time/ejection time ≤0.25 or right ventricular wall thickness in diastole ≥1.03 mm detected right ventricular systolic pressure ≥35.5 mmHg or Fulton's Index ≥0.34 with a sensitivity of 88% and specificity of 100%. With properly validated non-invasive echocardiography measures of right ventricular performance in rats that accurately predict invasive measures of pulmonary hemodynamics, future studies can now utilize these markers to test the efficacy of different treatments with preclinical therapeutic modeling.

Dyspnea in antiphospholipid syndrome: Beyond pulmonary embolism

Pulmonary embolism due to primary antiphospholipid syndrome is rarely associated with chronic thromboembolic pulmonary hypertension, and therefore according to the latest guidelines on pulmonary hypertension, routine screening is not recommended. We describe a young patient with a late diagnosis of chronic thromboembolic pulmonary hypertension in the context of pulmonary embolism, primary antiphospholipid syndrome and suboptimal anticoagulation. Of note, mild cardiopulmonary symptoms were consistently misattributed to a depressive disorder because physical examination was normal, serial Doppler echocardiography failed to show pulmonary hypertension, and all other diagnostic tests were normal. Once symptoms became severe, positive screening tests led to the correct diagnosis and surgical referral, and bilateral pulmonary endarterectomy was successfully performed. This case demonstrates the need for extra awareness in patients with antiphospholipid syndrome and pulmonary embolism.

Echocardiographic Assessment of Right Ventricular Function and Response to Therapy in Pulmonary Arterial Hypertension

Echocardiography is a key tool in the management of patients with pulmonary arterial hypertension (PAH), but many potential parameters could be used to assess response to therapy. In this retrospective study of 48 patients with severe PAH at baseline, we examined echocardiographic variables before and after initiation of PAH-specific therapy to evaluate which measures of right ventricular (RV) function best correlated with clinical response to therapy as assessed by 6-minute walk distance (6MWD) and 3-year all-cause mortality. Tricuspid annular plane systolic excursion (TAPSE), mid-RV and basal-RV diameters, RV systolic pressure, and RV global longitudinal strain were all found to significantly improve after initiation of a PAH therapy. Decreases in right atrial area (r = -0.50, p = 0.002) and mid-RV diameter (r = -0.36, p = 0.03) were most strongly correlated with improvement in 6MWD. Pretreatment values of RA area (hazard ratio [HR] per 1 SD: 2.72; 95% confidence interval [CI] 1.58, 4.69), mid-RV diameter (HR 2.03; 1.20, 3.45), basal-RV diameter (HR 2.27; 1.40, 3.70), and RV global longitudinal strain (HR 2.36; 1.22, 4.56) were all associated with mortality risk. 6MWD and TAPSE were the 2 variables for which pretreatment measures (6MWD - HR 0.35; 0.17, 0.72; TAPSE - HR 0.41; 0.21, 0.82) and change with treatment (6MWD - HR 0.26; 0.10, 0.64; TAPSE - HR 0.40; 0.21, 0.77) were both significantly associated with 3-year mortality. Change in RV systolic pressure with treatment was significantly associated with mortality (HR 2.55; 1.23, 5.28,) but pretreatment baseline had no association (HR 1.48; 0.72, 3.06). Although many echocardiographic parameters change with initiation of PAH treatment, the strong association of both baseline TAPSE and change in TAPSE with mortality supports the ongoing use of TAPSE as an important measure in the assessment of disease severity and treatment response in PAH.

Noninvasive Assessment of Right Ventricular Function in Patients with Pulmonary Arterial Hypertension and Left Ventricular Assist Device

PURPOSE OF REVIEW

Right ventricular (RV) failure in patients with pulmonary arterial hypertension (PAH) and left ventricular assist device (LVAD) is associated with increased hospitalizations, worsening functional class, and poor survival. Accurate RV function assessment is essential in diagnosing RV failure, guiding therapies, and determining prognosis. Noninvasive imaging techniques provide fast and reliable quantification of RV morphology and function.

RECENT FINDINGS

We review echocardiography, nuclear medicine, and cardiac magnetic resonance imaging (MRI) uses for RV function assessment in patients with PAH and LVAD. We identify current knowledge gaps in utilizing noninvasive tests to assess RV function. Echocardiography is most widely used to quantify RV function in patients with PAH and LVAD, followed by cardiac MRI for RV morphology and function measurement in PAH patients. The first-pass radionuclide angiography with radiolabeled RBC is the gold standard for calculating RV function. Gated blood pool SPECT can be an alternative as it separates the cardiac chambers well and provides accurate assessment of the RV function with high reproducibility, which is particularly useful for monitoring treatment. More research is needed to compare and validate these modalities in evaluating RV function.

Pulmonary Arterial Hypertension and Therapeutic Interventions

Pulmonary hypertension is an uncommon disease that carries a significant morbidity and mortality. Pulmonary arterial hypertension is a subtype of pulmonary hypertension that describes a group of disease entities that lead to an elevation in precapillary pulmonary artery pressure. Despite advances in the diagnosis and treatment of pulmonary arterial hypertension, it remains a difficult disease to recognize and manage. In this review article, we will discuss the definition and diagnosis of pulmonary arterial hypertension. Additionally, we will discuss the ever-expanding management options, their mechanisms and strategies, including combination therapy and the most recent advances and future directions.

Noninvasive Bedside Vasodilator Testing Using Echocardiography

•

Echocardiography was used for bedside vasodilator testing in postoperative PH.

•

Echocardiographic measures of PH and RV function improved shortly after nitric oxide.

•

Echocardiography was used to guide management and avoid more invasive testing.

Risk classification of pulmonary arterial hypertension by echocardiographic combined assessment of pulmonary vascular resistance and right ventricular function

Which combination of clinical parameters improves the prediction of prognosis in patients with pulmonary arterial hypertension (PAH) remains unclear. We examined whether combined assessment of pulmonary vascular resistance and right ventricular function by echocardiography is useful for classifying risks in PAH. In 41 consecutive patients with PAH (mean age of 48.9 ± 17.3 years, 31 females), a 6-min walk test, pulmonary function test, and echocardiography were performed at baseline and during PAH-specific therapies. The study endpoint was defined as a composite of cardiovascular death and hospitalization for PAH and/or right ventricular failure. During a follow-up period of 9.2 ± 8.7 months, 18 patients reached the endpoint. Multivariate regression analysis showed that the ratio of tricuspid regurgitation pressure gradient to the time-velocity integral of the right ventricular outflow tract (TRPG/TVI) and tricuspid annular plane systolic excursion (TAPSE) during PAH-specific treatment were independent prognostic predictors of the endpoint. Using cutoff values indicated by receiver operating characteristic analysis, the patients were divided into four subsets. Multivariate analyses by Cox's proportional hazards model adjusted for age, sex and body mass index indicated that subset 4 (TRPG/TVI ≥ 3.89 and TAPSE ≤ 18.9 mm) had a significantly higher event risk than did subset 1 (TRPG/TVI < 3.89 and TAPSE > 18.9 mm): HR = 25.49, 95% CI 4.70-476.97, p < 0.0001. Combined assessment of TRPG/TVI and TAPSE during adequate PAH-specific therapies enables classification of risks for death and/or progressive right heart failure in PAH.

Relevance of the TAPSE/PASP ratio in pulmonary arterial hypertension

BACKGROUND

The ratio of echocardiography-derived tricuspid annular plane systolic excursion (TAPSE) and pulmonary arterial systolic pressure (PASP) has recently been reported as an independent prognostic parameter in heart failure. The TAPSE/PASP ratio has not been evaluated in detail in patients with pulmonary arterial hypertension (PAH).

METHODS

We analyzed TAPSE/PASP in 290 patients with PAH entered into the Giessen Pulmonary Hypertension Registry between November 2003 and July 2014. The prognostic relevance of TAPSE/PASP was assessed with multivariate Cox regression models, adjusting for clinical covariates, echocardiographic parameters, or hemodynamics, and was confirmed by Kaplan-Meier analyses.

RESULTS

When stratified by tertile of TAPSE/PASP (low: <0.19 mm/mmHg; middle: 0.19-0.32 mm/mmHg; high: >0.32 mm/mmHg), patients in the low tertile showed significantly compromised hemodynamic, functional, and echocardiographic status compared with patients in the middle and high tertiles. In all multivariate models, TAPSE/PASP remained independently associated with overall mortality: the hazard ratio (95% confidence interval) was 1.87 (1.35-2.59) when adjusting for clinical covariates (p < .001), 5.21 (2.17-12.5) when adjusting for echocardiographic parameters (p < .001), 1.92 (1.30-2.83) when adjusting for hemodynamics (p = .001), and 4.13 (2.02-8.48) when adjusting for a selection of previously identified independent echocardiographic and hemodynamic prognostic indicators (p < .001). Kaplan-Meier analyses showed better overall survival in the middle and high tertiles versus the low tertile (log-rank p < .001).

CONCLUSIONS

The TAPSE/PASP ratio is a meaningful prognostic parameter in patients with PAH and is associated with hemodynamics and functional class.

Current and emerging imaging techniques in the diagnosis and assessment of pulmonary hypertension

INTRODUCTION

Pulmonary hypertension (PH) is a challenging condition to diagnose and treat. Over the last two decades, there have been significant advances in therapeutic approaches and imaging technologies. Current guidelines emphasize the importance of cardiac catheterization; however, the increasing availability of non-invasive imaging has the potential to improve diagnostic rates, whilst providing additional information on patient phenotypes. Areas covered: This review discusses the role of imaging in the diagnosis, prognostic assessment and follow-up of patients with PH. Imaging methods, ranging from established investigations (chest radiography, echocardiography, nuclear medicine and computerized tomography (CT)), to emerging modalities (dual energy CT, magnetic resonance imaging (MRI), optical coherence tomography and positron emission tomography (PET)) are reviewed. The value and limitations of the clinical utility of these imaging modalities and their potential clinical application are reviewed. Expert commentary: Imaging plays a key role in the diagnosis and classification of pulmonary hypertension. It also provides valuable prognostic information and emerging evidence supports a role for serial assessments. The authors anticipate an increasing role for imaging in the pulmonary hypertension clinic. This will reduce the need for invasive investigations, whilst providing valuable insights that will improve our understanding of disease facilitate a more targeted approach to treatment.

Endothelial Phenotype Evoked by Low Dose Carvedilol in Pulmonary Hypertension

Background: The therapeutic benefits of β-blockers are well established in left heart failure. The Pulmonary Arterial Hypertension Treatment with Carvedilol for Heart Failure [PAHTCH] study showed safety and possible benefit of carvedilol in pulmonary arterial hypertension (PAH) associated right heart failure over 6 months. This study aims at evaluating the short-term cardiovascular effects and early mechanistic biomarkers of carvedilol therapy.

Methods: Thirty patients with pulmonary hypertension (PH) received low dose carvedilol (3.125 mg twice daily) for 1 week prior to randomization to placebo, low-dose, or dose-escalating carvedilol therapy. Echocardiography was performed at baseline and 1 week. Exercise capacity was assessed by 6 min walk distance (6MWD). The L-arginine/nitric oxide pathway and other biological markers of endothelial function were measured.

Results: All participants tolerated 1 week of carvedilol without adverse effects. After 1 week of carvedilol, 6MWD and heart rate at peak exercise did not vary (both p > 0.1). Heart rate at rest and 1 min post walk dropped significantly (both p < 0.05) with a trend for increase in heart rate recovery (p = 0.08). Right ventricular systolic pressure (RVSP) decreased by an average of 13 mmHg (p = 0.002). Patients who had a decrease in RVSP of more than 10 mm Hg were defined as responders (n = 17), and those with a lesser drop as non-responders (n = 13). Responders had a significant drop in pulmonary vascular resistance (PVR) after 1 week of carvedilol (p = 0.004). In addition, responders had a greater decrease in heart rate at rest and 1 min post walk compared to non-responders (both p < 0.05). Responders had higher plasma arginine and global bioavailability of arginine at baseline compared to non-responders (p = 0.03 and p = 0.05, respectively). After 1 week of carvedilol, responders had greater increase in urinary nitrate (p = 0.04). Responders treated with carvedilol had a sustained drop in RVSP and PVR after 6 months of carvedilol with no change in cardiac output.

Conclusions: Low-dose carvedilol for 1 week can potentially identify a PH responder phenotype that may benefit from β-blockers that is associated with less endothelial dysfunction.

Clinical Trial Registration:http://www.clinicaltrials.gov. identifier: NCT01586156.

Clinical and Echocardiographic Predictors of Outcomes in Patients With Pulmonary Hypertension

In pulmonary hypertension (PH), measurement of various echocardiographic parameters that assess right heart function is recommended by current clinical guidelines. Limited data exists on the combined value of clinical and echocardiographic parameters in precapillary PH in the modern era of therapy. We examined the association of clinical and echocardiographic parameters with surrogate outcomes (6-minute walk distance) and hard outcomes (hospitalization or death) in patients with precapillary PH. A cohort of patients with an established diagnosis of precapillary PH who underwent transthoracic echocardiography at the Duke Echo Lab were prospectively enrolled from 2010 to 2014. Univariable and multivariable models were constructed to examine the relation of clinical and echocardiographic parameters with surrogate and hard outcomes. Of the 98 patients with analyzable echocardiograms with good image quality, 85 were woman, mean age was 59.4 years, and 47% had ≥World Health Organization functional class III symptoms. The mean 6-minute walk distance was 354(±132) m, and 83% were on pulmonary arterial hypertension medications. At 24 months, the cumulative incidence rate for hospitalization or death was 47%. In univariable analyses, the REVEAL (Registry to Evaluate Early and Long-term PAH Disease Management) risk score (HR 1.72 per 1 SD (2.81) increment, 95% CI 1.34, 2.22; p=<0.001), RV global longitudinal strain (RVGLS) (HR 1.54 per 1 SD (5.31) worsening, 95% CI , 2.12; p=0.008) and log-2 NT proBNP (HR 1.43 per 1-fold increase, 95% CI 1.25, 1.63; p=<0.001) were significantly associated with hospitalization or death.

Pulmonary vascular resistance versus pulmonary artery pressure for predicting right ventricular remodeling and functional tricuspid regurgitation

BACKGROUND

Pulmonary hypertension (PH) is a common cause of right ventricular (RV) remodeling and functional tricuspid regurgitation (FTR), but incremental pulmonary artery systolic pressure (PASP) does not always correlate with anatomic and functional RV changes. This study aimed to evaluate a noninvasive measure of pulmonary vascular resistance (PVR) for predicting RV dilatation, RV dysfunction, and severity of FTR.

METHODS

We prospectively analyzed consecutive stable patients with PASP ≥ 35 mm Hg or any degree of RV dilatation or dysfunction secondary to PH. Noninvasive PVR was calculated based on FTR peak velocity and flow in RV outflow tract.

RESULTS

We included 251 patients, aged 72.1 ± 11.4 years, 53% women, 74.9% with type 2 pulmonary hypertension. The mean PASP was 48.3 ± 12.2 mm Hg. Both PASP and PVR significantly correlated with FTR, RV dilatation, and RV systolic dysfunction. After dichotomizing FTR and RV dilatation and systolic dysfunction as nonsignificant vs significant, FTR and RV dilatation were similarly predicted by PASP and PVR, but RV dysfunction was better predicted by PVR (AUC = 0.78 [0.72-0.84] vs 0.66 [0.60-0.73] for PASP, P < 0.001). Patients with low PASP but high PVR showed worse RV and left ventricular function but lower rates of right heart failure and smaller inferior vena cava, compared to patients with high PASP but low PVR.

CONCLUSIONS

Noninvasive PVR was superior to PASP for predicting RV systolic dysfunction, but both were similarly associated with RV dilatation or FTR grade. PASP and PVR complement each other to define the echocardiographic findings and clinical status of the patient.

Prevalence, Predictors, and Prognostic Value of Residual Tricuspid Regurgitation in Patients With Left Ventricular Assist Device

Background

Although implantation of a left ventricular assist device (LVAD) generally improves tricuspid regurgitation (TR) in short‐term follow‐up, the clinical significance of residual TR in patients with mid‐ to long‐term LVAD support is unknown. This study aimed to identify the prevalence, predictors, and prognostic value of residual TR in LVAD patients in association with tricuspid valve (TV) deformation.

Methods and Results

The study cohort consisted of 127 patients who underwent LVAD implantation without TV procedure and were supported with LVAD at least 1 year. All patients underwent echocardiographic examination preoperatively and 1 year after LVAD implantation. TR was quantitatively assessed by ratio of TR color jet area/right atrial area, and significant residual TR was defined as ≥20% of %TR at follow‐up echocardiographic examination. Detailed echocardiographic measurements were also performed, including TV annulus diameter, TV leaflet displacement, and left ventricular and right ventricular systolic function. LVAD implantation significantly improved ratio of TR color jet area/right atrial area as well as left ventricular and right ventricular systolic function and tethering distance (all P<0.05), whereas it enlarged TV annulus diameter (P=0.002). Significant residual TR was observed in 30 (23.6%) patients. Age, preoperative TV annulus diameter, and residual mitral regurgitation were significantly associated with significant residual TR (all P<0.05), whereas TV tethering was not. During a mean follow‐up of 21±17 months, patients with residual TR had significantly higher mortality than those without residual TR (log‐rank P<0.001).

Conclusions

Significant residual TR was observed in ≈25% patients supported with LVAD over 1 year and was associated with unfavorable outcome.

Three-dimensional speckle-tracking echocardiography: benefits and limitations of integrating myocardial mechanics with three-dimensional imaging

Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) is an advanced imaging technique designed for left ventricular (LV) myocardial deformation analysis based on 3D data sets. 3DSTE has the potential to overcome some of the intrinsic limitations of two-dimensional STE (2DSTE) in the assessment of complex LV myocardial mechanics, offering additional deformation parameters (such as area strain) and a comprehensive quantitation of LV geometry and function from a single 3D acquisition. Albeit being a relatively young technique still undergoing technological developments, several experimental studies and clinical investigations have already demonstrated the reliability and feasibility of 3DSTE, as well as several advantages of 3DSTE over 2DSTE. This technique has provided new insights into LV mechanics in several clinical fields, such as the objective assessment of global and regional LV function in ischemic and non-ischemic heart diseases, the evaluation of LV mechanical dyssynchrony, as well as the detection of subclinical cardiac dysfunction in cardiovascular conditions at risk of progression to overt heart failure. However, 3DSTE generally requires patient's breathhold and regular rhythm for enabling an ECG-gated multi-beat 3D acquisition. In addition, the measurements, normal limits and cut-off values pertaining to 3D strain parameters are currently vendor-specific and highly dependent on the 3D ultrasound equipment used. Technological advances with improvement in spatial and temporal resolution and a standardized methodology for obtaining vendor-independent 3D strain measurements are expected in the future for a widespread application of 3DSTE in both clinical and research arenas. The purpose of this review is to summarize currently available data on 3DSTE methodology (feasibility, accuracy and reproducibility), strengths and weaknesses with respect to 2DSTE, as well as the main clinical applications and future research priorities of this emerging technology.

Three-Dimensional Echocardiography-Derived Non-Invasive Right Ventricular Pressure-Volume Analysis

In patients with pulmonary hypertension, repeated evaluations of right ventricular (RV) function are still required for clinical decision making, but the invasive nature of current pressure-volume analysis makes conducting regular follow-ups in a clinical setting infeasible. We enrolled 12 patients with pulmonary arterial hypertension (PAH) and 10 with pulmonary venous hypertension (PVH) May 2016-October 2016. All patients underwent a clinically indicated right heart catheterization (RHC), from which the yielded right ventricular pressure recordings were conjugated with RV volume by 3-D echocardiography to generate a pressure-volume loop. A continuous-wave Doppler envelope of tricuspid regurgitation was transformed into a pressure gradient recording by the simplified Bernoulli equation, and then a systolic pressure gradient-volume (PG-V) diagram was generated from similar methods. The area enclosed by the pressure-volume loop was calculated to represent semi-invasive right ventricular stroke work (RVSW_RHC). The area between the PG-V diagram and x-axis was calculated to estimate non-invasive RVSW (RVSW_echo). Patients with PAH have higher RV pressure, lower pulmonary arterial wedge pressure and larger RV volume that was contributed by the dilation of RV mid-cavity minor dimension. We found no significant difference of traditional parameters between these two groups, but RVSW values were significantly higher in PAH patients. The RVSW values of these two methods were significantly correlated by the equation RVSW_echo = 0.8447 RVSW_RHC + 129.38 (R² = 0.9151, p < 0.001). The linearity remained satisfactory in both groups. We conclude that a PG-V diagram is a reliable method to estimate RVSW and to depict pathophysiological status.

Epigenetics, inflammation and metabolism in right heart failure associated with pulmonary hypertension

Right ventricular failure (RVF) is the most important prognostic factor for both morbidity and mortality in pulmonary arterial hypertension (PAH), but also occurs in numerous other common diseases and conditions, including left ventricle dysfunction. RVF remains understudied compared with left ventricular failure (LVF). However, right and left ventricles have many differences at the morphological level or the embryologic origin, and respond differently to pressure overload. Therefore, knowledge from the left ventricle cannot be extrapolated to the right ventricle. Few studies have focused on the right ventricle and have permitted to increase our knowledge on the right ventricular-specific mechanisms driving decompensation. Here we review basic principles such as mechanisms accounting for right ventricle hypertrophy, dysfunction, and transition toward failure, with a focus on epigenetics, inflammatory, and metabolic processes.

Echocardiographic evaluation of the right ventricle: Clinical implications

Interest in evaluation of the right ventricle (RV) has increased recently. With the growth of new echocardiographic techniques and technology, there has been a corresponding increase in the ability to evaluate the RV, both qualitatively and quantitatively. Older echocardiographic techniques, such as right ventricular fractional area of change, tricuspid annular plane systolic excursion, and tissue S', and newer echocardiographic techniques including 3-dimensional evaluation and global longitudinal strain, can improve our evaluation of RV function. These techniques provide both diagnostic and prognostic data on a large variety of clinical diseases including pulmonary hypertension and congestive heart failure. With the continuing and exponential advances in technology, echocardiography is well poised to become the primary modality to evaluate the RV.

A Simple Method for Noninvasive Quantification of Pressure Gradient Across the Pulmonary Valve

Pressure gradient across the pulmonary valve (PVPG) is an important hemodynamic variable used in the management of patients with cardiovascular and pulmonary disease. However, a reliable noninvasive method is unavailable. We hypothesized that a progressive Muller maneuver would elicit the pulmonary valve premature opening (PVPO) in diastole and that this event would be detectable by Doppler echocardiography. The intrathoracic pressure (ITP) decrease during this maneuver equals PVPG, which may be assessed with a custom airway pressure measurement device. A total of 102 subjects were enrolled in the study. At the earliest appearance of PVPO, the ITP decrease was recorded as the PVPG. PVPG was also simultaneously measured and compared by other two methods: right heart catheterization in 43 subjects, and routine Doppler echocardiography (pulmonary regurgitation jet) in the other 59 subjects. The results measured by different approaches were compared using the Bland-Altman analysis. PVPG assessed via PVPO showed strong agreement with PVPG measured by catheterization or routine Doppler echocardiography methods, with Lin concordance correlation coefficients of 0.91 and 0.70, respectively. In conclusion, PVPO provides a new noninvasive method of quantification of PVPG.

Right heart function during simulated altitude in patients with pulmonary arterial hypertension

OBJECTIVE

Patients with pulmonary arterial hypertension (PAH) are often recommended supplemental oxygen for altitude travel due to the possible deleterious effects of hypoxia on pulmonary haemodynamics and right heart function. This includes commercial aircraft travel; however, the direct effects and potential risks are unknown.

METHODS

Doppler echocardiography and gas exchange measures were investigated in group 1 patients with PAH and healthy patients at rest breathing room air and while breathing 15.1% oxygen, at rest for 20 min and during mild exertion.

RESULTS

The 14 patients with PAH studied were clinically stable on PAH-specific therapy, with functional class II (n=11) and III (n=3) symptoms when tested. Measures of right ventricular size and function were significantly different in the PAH group at baseline as compared to 7 healthy patients (p<0.04). There was no evidence of progressive right ventricular deterioration during hypoxia at rest or under exertion. Pulmonary arterial systolic pressure (PASP) increased in both groups during hypoxia (p<0.01). PASP in hypoxia correlated strongly with baseline PASP (p<0.01). Pressure of arterial oxygen correlated with PASP in hypoxia (p<0.03) but not at baseline, with three patients with PAH experiencing significant desaturation. The duration and extent of hypoxia in this study was tolerated well despite a mild increase in symptoms of breathlessness (p<0.01).

CONCLUSIONS

Non-invasive measures of right heart function in group 1 patients with PAH on vasodilator treatment demonstrated a predictable rise in PASP during short-term simulated hypoxia that was not associated with a deterioration in right heart function.