Right Ventricular Strain Curve Morphology and Outcome in Idiopathic Pulmonary Arterial Hypertension

The association of Pulmonary Hypertension and right ventricular systolic function - updates in diagnosis and treatment

Right ventricular (RV) systolic function is an essential but neglected component in cardiac evaluation, and its importance to the contribution to overall cardiac function is undermined. It is not only sensitive to the effect of left heart valve disease but is also more sensitive to changes in pressure overload than the left ventricle. Pulmonary Hypertension is the common and well-recognized complication of RV systolic dysfunction. It is also the leading cause of pulmonary valve disease and right ventricular dysfunction. Patients with a high pulmonary artery pressure (PAP) and a low RV ejection fraction have a seven-fold higher risk of death than heart failure patients with a normal PAP and RV ejection fraction. Furthermore, it is an independent predictor of survival in these patients. In this review, we examine the association of right ventricular systolic function with Pulmonary Hypertension by focusing on various pathological and clinical manifestations while assessing their impact. We also explore new 2022 ESC/ERS guidelines for diagnosing and treating right ventricular dysfunction in Pulmonary Hypertension.

Prognostic value of right ventricular dyssynchrony in adults with repaired tetralogy of Fallot

OBJECTIVE

Residual sequelae after surgical repair of tetralogy of Fallot (rTOF) affect clinical outcome. We investigated the prognostic impact of right ventricular (RV) dyssynchrony in adults with rTOF years after the surgical repair.

METHODS

Patients from the Swiss Adult Congenital HEart disease Registry were included. NT-proBNP levels, echocardiography, exercise testing and MRI data were collected. An offline strain analysis to quantify RV-ventricular and interventricular dyssynchrony was performed. The standard deviation of the time-to-peak shortening (TTP) of six RV segments defined the RV Dyssynchrony Index (RVDI). Maximal difference of TTP between RV and left ventricular segments defined the interventricular shortening delay (IVSD). Predictors of a composite adverse event (arrhythmias, hospitalisation for heart failure and death) were identified by multivariate Cox regression analysis. Their median values were used to create a risk score.

RESULTS

Out of 285 included patients (mean age 34±14 years), 33 patients (12%) experienced an adverse event during a mean follow-up of 48±21 months. No correlation was found between RVDI, IVSD and clinical events. NT-proBNP, right atrial area and peak heart rate were independent predictors of outcomes. After 4 years-follow-up, no adverse events occurred in patients at low risk (score=0 points), while an adverse event occurred in 62% of patients at high risk (score=3 points, p<0.001).

CONCLUSION

In our cohort of adults with rTOF, surrogates of RV dyssynchrony did not correlate with outcomes. A multimodality approach was effective in predicting the risk for adverse events.

Prognostic value of deep echocardiographic phenotyping in pulmonary arterial hypertension

Background

A novel approach to derive prognostic information from echocardiography in pulmonary arterial hypertension (PAH) is to define a phenotype of right heart function combining standard echocardiographic parameters which describe right ventricular pump function and systemic venous congestion. We tested the hypothesis that the combination of advanced strain imaging parameters could yield high prognostic accuracy.

Methods

This was a prospective observational study with a single centre derivation cohort and a second centre validation cohort. The derivation cohort included 49 naive PAH patients who underwent right heart catheterisation and echocardiographic evaluation at baseline and 4-12 months after diagnosis. The validation cohort included 83 prevalent PAH patients who underwent the same examinations at 12 months after diagnosis. We stratified the risk of the derivation cohort according to three models: Model 1, based on haemodynamic parameters; Model 2, based on standard echocardiographic parameters; and Model 3, based on advanced echocardiographic parameters. The median follow-up period was 21 months; the end point of the analysis was clinical worsening.

Results

In the derivation cohort, haemodynamic and echocardiographic parameters obtained at diagnosis were not associated with outcome, whereas a significant association was observed at first reassessment. Model 3 yielded a better predictive accuracy (Harrell's C index 0.832) as compared to Model 2 (Harrell's C index 0.667), and to Model 1 (Harrell's C index 0.713). The validation cohort confirmed the accuracy of Model 3.

Conclusions

A comprehensive assessment of right heart function using right ventricular strain, right atrial reservoir strain and degree of tricuspid regurgitation provides accurate prognostic information in prevalent PAH patients.

Biventricular Dysfunction and Ventricular Interdependence in Patients With Pulmonary Hypertension: A 3.0-T Cardiac MRI Feature Tracking Study

BACKGROUND

Pulmonary hypertension (PH) results in right ventricular (RV) dysfunction, subsequently leading to left ventricular (LV) impairment. The mechanism underlying ventricular interdependence is largely uninvestigated.

PURPOSE

To explore the biventricular dysfunction and the ventricular interdependence in PH patients.

STUDY TYPE

Retrospective.

POPULATION

One hundred and seven PH patients (mean pulmonary artery pressure >20 mmHg) and 72 age- and sex-matched controls with cardiac magnetic resonance imaging (MRI) studies.

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession sequence.

ASSESSMENT

LV and RV ejection fractions (EF) and RV and LV radial, circumferential, and longitudinal strains were assessed using commercial software. Strains were compared between controls, PH patients with preserved RVEF (RVEF ≥40%, N = 48), and PH patients with reduced RVEF (RVEF <40%, N = 59).

STATISTICAL TESTS

Chi-squared tests or Fisher's exact test, t tests or Mann-Whitney U test, one-way ANOVA with Bonferroni's post hoc correction or Kruskal-Wallis test, Pearson or Spearman correlation, and multivariable linear regression analysis. A two-tailed P < 0.05 was deemed statistically significant.

RESULTS

RV strain decreased sequentially from controls, through PH with preserved RVEF, to PH with reduced RVEF. PH patients with reduced RVEF had significantly lower LV strain, especially septal strain, and LV peak diastolic strain rate compared with both controls and PH patients with preserved RVEF. Multivariable analyses showed that RVEF was independently correlated with LV strain; furthermore, independent of RVEF, RV strain was significantly correlated with LV strain (LVGRS: β = 0.416; LVGCS: β = -0.371; LVGLS: β = 0.283).

DATA CONCLUSION

Subclinical impairment of RV function was found in PH with preserved RVEF. LV strain was impaired when RV was dysfunctional, which was associated with worsening RV strain. Therefore, while focusing on improving RV function, LV dysfunction in PH patients should also be monitored and treated early in order to slow the progression of the disease.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Echocardiographic pressure-strain loop-derived stroke work of the right ventricle: validation against the gold standard

AIMS

Commercially available integrated software for echocardiographic measurement of stroke work (SW) is increasingly used for the right ventricle, despite a lack of validation. We sought to assess the validity of this method [echo-based myocardial work (MW) module] vs. gold-standard invasive right ventricular (RV) pressure-volume (PV) loops.

METHODS AND RESULTS

From the prospectively recruiting EXERTION study (NCT04663217), we included 42 patients [34 patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) and 8 patients with absence of cardiopulmonary disease] with RV echocardiography and invasive PV catheterization. Echocardiographic SW was assessed as RV global work index (RVGWI) generated via the integrated pressure-strain MW software. Invasive SW was calculated as the area bounded by the PV loop. An additional parameter derived from the MW module, RV global wasted work (RVGWW), was correlated with PV loop measures. RVGWI significantly correlated with invasive PV loop-derived RV SW in the overall cohort [rho = 0.546 (P < 0.001)] and the PAH/CTEPH subgroup [rho = 0.568 (P < 0.001)]. Overall, RVGWW correlated with invasive measures of arterial elastance (Ea), the ratio of end-systolic elastance (Ees)/Ea, and end-diastolic elastance (Eed) significantly.

CONCLUSIONS

Integrated echo measurement of pressure-strain loop-derived SW correlates with PV loop-based assessment of RV SW. Wasted work correlates with invasive measures of load-independent RV function. Given the methodological and anatomical challenges of RV work assessment, evolution of this approach by incorporating more elaborated echo analysis data and an RV reference curve might improve its reliability to mirror invasively assessed RV SW.

Echocardiographic evaluation of right ventricular diastolic function in pulmonary hypertension

Background

Right ventricular (RV) diastolic dysfunction may be prognostic in pulmonary hypertension (PH). However, its assessment is complex and relies on conductance catheterisation. We aimed to evaluate echocardiography-based parameters as surrogates of RV diastolic function, provide validation against the gold standard, end-diastolic elastance (Eed), and define the prognostic impact of echocardiography-derived RV diastolic dysfunction.

Methods

Patients with suspected PH who underwent right heart catheterisation including conductance catheterisation were prospectively recruited. In this study population, an echocardiography-based RV diastolic function surrogate was derived. Survival analyses were performed in patients with precapillary PH in the Giessen PH Registry, with external validation in patients with pulmonary arterial hypertension at Sapienza University (Rome).

Results

In the derivation cohort (n=61), the early/late diastolic tricuspid inflow velocity ratio (E/A) and early tricuspid inflow velocity/early diastolic tricuspid annular velocity ratio (E/e') did not correlate with Eed (p>0.05). Receiver operating characteristic analysis revealed a large area under the curve (AUC) for the peak lateral tricuspid annulus systolic velocity/right atrial area index ratio (S'/RAAi) to detect elevated Eed (AUC 0.913, 95% confidence interval (CI) 0.839-0.986) and elevated end-diastolic pressure (AUC 0.848, 95% CI 0.699-0.998) with an optimal threshold of 0.81 m2·s-1·cm-1. Subgroup analyses demonstrated a large AUC in patients with preserved RV systolic function (AUC 0.963, 95% CI 0.882-1.000). Survival analyses confirmed the prognostic relevance of S'/RAAi in the Giessen PH Registry (n=225) and the external validation cohort (n=106).

Conclusions

Our study demonstrates the usefulness of echocardiography-derived S'/RAAi for noninvasive assessment of RV diastolic function and prognosis in PH.

Ratio between right ventricular longitudinal strain and pulmonary arterial systolic pressure: A novel prognostic parameter in patients with severe tricuspid regurgitation

BACKGROUND

In terms of pathophysiology, tricuspid regurgitation (TR), right ventricular function and pulmonary artery pressure are linked to each other. Our aim was to analyze whether the echocardiography-derived right ventricular free wall longitudinal strain/pulmonary artery systolic pressures (RVFWLS/PASP) ratio can improve risk stratification in patients with severe tricuspid regurgitation (TR).

METHODS

In this single-center retrospective study, 250 consecutive patients with severe TR were enrolled from December 2015 to December 2018. Baseline clinical and echocardiographic parameters were collected. Echocardiography-derived TAPSE/PASP and RVFWLS/PASP were evaluated. The primary endpoint was all-cause mortality.

RESULTS

Out of 250 consecutive patients, 171 meet inclusion criteria. Patients were predominantly female, with several cardiovascular risk factors and comorbidities. RVFWLS/PASP ≤0.34%/mmHg (AUC 0.68, p < 0.001, sensitivity 70%, specificity 67%) was associated with baseline clinical RV heart failure (p = 0.03). After univariate and multivariate analyses, RVFWLS/PASP, but not TAPSE/PASP, independently correlated with all-cause mortality (HR 0.004, p = 0.02). Patients with RVFWLS/PASP >0.26%/mmHg (AUC 0.74, p < 0.001, sensitivity 77%, specificity 52%) showed higher survival rates (p = 0.02). In addition at 24 months follow-up, the Kaplan-Meyer curves showed patients with RVFWLS >14% & RVFWLS/PASP >0.26%/mmHg had the best survival rate compared to patients without.

CONCLUSION

RVFWLS/PASP is independently associated with baseline RV heart failure and poor long-term prognosis in patients with severe TR.

Assessment of Right Ventricular Function-a State of the Art

PURPOSE OF REVIEW

The right ventricle (RV) has a complex geometry and physiology which is distinct from the left. RV dysfunction and failure can be the aftermath of volume- and/or pressure-loading conditions, as well as myocardial and pericardial diseases.

RECENT FINDINGS

Echocardiography, magnetic resonance imaging and right heart catheterisation can assess RV function by using several qualitative and quantitative parameters. In pulmonary hypertension (PH) in particular, RV function can be impaired and is related to survival. An accurate assessment of RV function is crucial for the early diagnosis and management of these patients. This review focuses on the different modalities and indices used for the evaluation of RV function with an emphasis on PH.

The heart of the matter: Right heart imaging indicators for treatment escalation in pulmonary arterial hypertension

Right heart (RH) structure and function are major determinants of symptoms and prognosis in pulmonary arterial hypertension (PAH). RH imaging provides detailed information, but evidence and guidelines on the use of RH imaging in treatment decisions are limited. We conducted a Delphi study to gather expert opinion on the role of RH imaging in decision-making for treatment escalation in PAH. A panel of 17 physicians with expertise in PAH and RH imaging used three surveys in a modified Delphi process to reach consensus on the role of RH imaging in PAH. Survey 1 used open-ended questions to gather information. Survey 2 contained Likert scale and other questions intended to identify consensus on topics identified in Survey 1. Survey 3 contained Likert scale questions derived from Survey 2 and summary information on the results of Survey 2. The Delphi panel reached consensus that RH imaging is likely to improve the current risk stratification algorithms and help differentiate risk levels in patients at intermediate risk. Tricuspid annular plane systolic excursion, right ventricular fractional area change, right atrial area, tricuspid regurgitation, inferior venae cavae diameter, and pericardial effusion should be part of routine echocardiography in PAH. Cardiac magnetic resonance imaging is valuable but limited by cost and access. A pattern of abnormal RH imaging results should prompt consideration of hemodynamic evaluation and possible treatment escalation. RH imaging is an important tool for decisions about treatment escalation in PAH, but systematically collected evidence is needed to clarify its role.

Risk Stratification and Outcomes in Patients With Pulmonary Hypertension: Insights into Right Ventricular Strain by MRI Feature tracking

BACKGROUND

Despite a recommended multidimensional approach for pulmonary hypertension (PH) risk stratification and guidance of treatment decisions, this may not always be achievable in patients with advanced disease. One issue is the lack of an imaging modality to assess right ventricular (RV) structure and function abnormalities.

PURPOSE

To explore the risk stratification and prognostic value of cardiac MR feature tracking (MR-FT)-derived RV strain.

STUDY TYPE

Retrospective.

POPULATION

A total of 80 patients with idiopathic pulmonary artery hypertension (N = 52) or chronic thromboembolic PH (N = 28).

FIELD STRENGTH

A 1.5 T or 3.0 T, balanced steady-state free precession sequence.

ASSESSMENT

All patients underwent laboratory testing, right heart catheterization, and MR imaging (and in 37 cases, a cardiopulmonary exercise test was also performed) within a 1-month period. Cardiac functional parameters and both global longitudinal strain (GLS) and global circumferential strain (GCS) were analyzed. Patients were stratified into low, intermediate, and high-risk groups by guideline suggested stratified values of risk factors. The combined endpoint was death or hospitalization for congestive heart failure assessed during follow-up since the date of MR examination.

STATISTICAL TESTS

Kolmogorov-Smirnov's test, independent-sample t-tests, Wilcoxon's rank-sum tests, one-way analysis of variance, χ² tests or Fisher's exact test, receiver operating characteristic analysis, Kaplan-Meier survival analysis, and Cox regression analysis. A P value < 0.05 was considered statistically significant.

RESULTS

The median follow-up duration was 3.4 years. Thirty-five patients presented with combined endpoint including 10 cardiac deaths. RV structural and deformation impairments were significantly associated with combined endpoint (ejection fraction: 31.3% ± 13.2% vs. 38.0% ± 14.8%, hazard ratio [HR: 0.974; GLS: -14.5 [-18.6, -10.9] % vs. -20.4 [-26.0, -13.2] %, HR: 1.071; GCS: -9.8 [-14.5, -7.3] % vs. -12.3 [-19.9, -8.4] %, HR: 1.059). There were significant differences in RVGLS among low, intermediate, and high-risk groups (-19.3% ± 7.2% vs. -17.3% ± 9.4% vs. -11.5% ± 4.4% by cardiac functional class, -21.8% ± 7.3% vs. -19.4% ± 8.2% vs. -12.7 ± 5.3% by NT-proBNP, -19.7% ± 7.7 vs. -15.8% ± 6.5% vs. -12.6% ± 8.2% by cardiac index).

DATA CONCLUSION

RV deformation may aid risk stratification in patients with PH, providing crucial information for RV remodeling, pulmonary hemodynamic condition and exercise capacity.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Riociguat and the right ventricle in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are progressive diseases that can lead to right heart failure and death. Right ventricular dysfunction, hypertrophy and maladaptive remodelling are consequences of increased right ventricular (RV) afterload in PAH and CTEPH and are indicative of long-term outcomes. Because RV failure is the main cause of morbidity and mortality in PAH and CTEPH, successful treatments should lead to improvements in RV parameters. Riociguat is a soluble guanylate cyclase stimulator approved for the treatment of PAH and inoperable or persistent/recurrent CTEPH after pulmonary endarterectomy. This review examines the current evidence showing the effect of riociguat on the right ventricle, with particular focus on remodelling, function and structural parameters in preclinical models and patients with PAH or CTEPH.

Imaging the right atrium in pulmonary hypertension: A systematic review and meta-analysis

BACKGROUND

Right atrial (RA) imaging has emerged as a promising tool for the evaluation of patients with pulmonary hypertension (PH), albeit without systematic validation.

METHODS

PubMed, Web of Science and the Cochrane library were searched for studies investigating the prognostic value of RA imaging assessment in patients with PH from 2000 to June 2021 (PROSPERO Identifier: CRD42020212850). An inverse variance-weighted meta-analysis of univariable hazard ratios (HRs) was performed using a random effects model.

RESULTS

Thirty-five studies were included (3,476 patients with PH; 74% female, 86% pulmonary arterial hypertension). Risk of bias was low/moderate (Quality of Prognosis Studies checklist). RA area (HR 1.06; 95% confidence interval [CI] 1.04-1.08), RA indexed area (HR 1.09; 95% CI 1.04-1.14), RA peak longitudinal strain (PLS; HR 0.94; 95% CI 0.91-0.97) and RA total emptying fraction (HR 0.96; 95% CI 0.94-0.98) were significantly associated with combined end-points including death, clinical worsening and/or lung transplantation; RA volume and volume index showed marginal significant associations. RA area (HR 1.06; 95% CI 1.04-1.07), RA indexed area (HR 1.12; 95% CI 1.07-1.17) and RA PLS (HR 0.98; 95% CI 0.97-0.99) showed significant associations with mortality; RA total emptying fraction showed a marginal association.

CONCLUSIONS

Imaging-based RA assessment qualifies as a relevant prognostic marker in PH. RA area reliably predicts composite end-points and mortality, which underscores its clinical utility. RA PLS emerged as a promising imaging measure, but is currently limited by the number of studies and different acquisition methods.

Adaptive versus maladaptive right ventricular remodelling

Right ventricular (RV) function and its adaptation to increased afterload [RV-pulmonary arterial (PA) coupling] are crucial in various types of pulmonary hypertension, determining symptomatology and outcome. In the course of disease progression and increasing afterload, the right ventricle undergoes adaptive remodelling to maintain right-sided cardiac output by increasing contractility. Exhaustion of compensatory RV remodelling (RV-PA uncoupling) finally leads to maladaptation and increase of cardiac volumes, resulting in heart failure. The gold-standard measurement of RV-PA coupling is the ratio of contractility [end-systolic elastance (Ees)] to afterload [arterial elastance (Ea)] derived from RV pressure-volume loops obtained by conductance catheterization. The optimal Ees/Ea ratio is between 1.5 and 2.0. RV-PA coupling in pulmonary hypertension has considerable reserve; the Ees/Ea threshold at which uncoupling occurs is estimated to be ~0.7. As RV conductance catheterization is invasive, complex, and not widely available, multiple non-invasive echocardiographic surrogates for Ees/Ea have been investigated. One of the first described and best validated surrogates is the ratio of tricuspid annular plane systolic excursion to estimated pulmonary arterial systolic pressure (TAPSE/PASP), which has shown prognostic relevance in left-sided heart failure and precapillary pulmonary hypertension. Other RV-PA coupling surrogates have been formed by replacing TAPSE with different echocardiographic measures of RV contractility, such as peak systolic tissue velocity of the lateral tricuspid annulus (S'), RV fractional area change, speckle tracking-based RV free wall longitudinal strain and global longitudinal strain, and three-dimensional RV ejection fraction. PASP-independent surrogates have also been studied, including the ratios S'/RV end-systolic area index, RV area change/RV end-systolic area, and stroke volume/end-systolic volume. Limitations of these non-invasive surrogates include the influence of severe tricuspid regurgitation (which can cause distortion of longitudinal measurements and underestimation of PASP) and the angle dependence of TAPSE and PASP. Detection of early RV remodelling may require isolated analysis of single components of RV shortening along the radial and anteroposterior axes as well as the longitudinal axis. Multiple non-invasive methods may need to be applied depending on the level of RV dysfunction. This review explains the mechanisms of RV (mal)adaptation to its load, describes the invasive assessment of RV-PA coupling, and provides an overview of studies of non-invasive surrogate parameters, highlighting recently published works in this field. Further large-scale prospective studies including gold-standard validation are needed, as most studies to date had a retrospective, single-centre design with a small number of participants, and validation against gold-standard Ees/Ea was rarely performed.

Risk Stratification of Patients with Pulmonary Arterial Hypertension: The Role of Echocardiography

Background: Given the morbidity and mortality associated with pulmonary arterial hypertension (PAH), risk stratification approaches that guide therapeutic management have been previously employed. However, most patients remain in the intermediate-risk category despite initial therapy. Herein, we sought to determine whether echocardiographic parameters could improve the risk stratification of intermediate-risk patients. Methods: Prevalent PAH patients previously enrolled in observational studies at 3 pulmonary hypertension centers were included in this study. A validated PAH risk stratification approach was used to stratify patients into low-, intermediate-, and high-risk groups. Right ventricular echocardiographic parameters were used to further stratify intermediate-risk patients into intermediate-low- and intermediate-high-risk groups based on transplant-free survival. Results: From a total of 146 patients included in our study, 38 patients died over a median follow-up of 2.5 years. Patients with intermediate-/high-risk had worse echocardiographic parameters. Tricuspid annular plane systolic excursion (TAPSE) and the degree of tricuspid regurgitation (TR) were highly associated with survival (p < 0.01, p = 0.04, respectively) and were subsequently used to further stratify intermediate-risk patients. Among intermediate-risk patients, survival was worse for patients with TAPSE < 19 mm compared to those with TAPSE ≥ 19 mm (estimated one-year survival 74% vs. 96%, p < 0.01) and for patients with moderate/severe TR compared to those with no/trace/mild TR (estimated one-year survival 70% vs. 93%, p < 0.01). Furthermore, among intermediate-risk patients, those with both TAPSE < 19 mm and moderate/severe TR had an estimated one-year survival (56%) similar to that of high-risk patients (56%), and those with both TAPSE ≥ 19 mm and no/trace/mild TR had an estimated one-year survival (97%) similar to that of low-risk patients (95%). Conclusions: Echocardiography, a routinely performed, non-invasive imaging modality, plays a pivotal role in discriminating distinct survival phenotypes among prevalent intermediate-risk PAH patients using TAPSE and degree of TR. This can potentially help guide subsequent therapy.

Right Ventricular Postsystolic Strain Curve Morphology before and after Vasodilator Treatment in Idiopathic Pulmonary Arterial Hypertension

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RV function is an important prognostic factor in pulmonary arterial hypertension.

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Several echocardiographic parameters are needed for a complete RV function assessment.

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RV postsystolic strain patterns have a prognostic impact in IPAH.

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RV postsystolic strain patterns may help in evaluating treatment response.

Comment on Topyła-Putowska et al. Echocardiography in Pulmonary Arterial Hypertension: Comprehensive Evaluation and Technical Considerations. J. Clin. Med. 2021, 10, 3229

A comprehensive PAH echocardiographic examination of patients with pulmonary arterial hypertension (PAH) should include a set of parameters resembling the pathophysiological changes occurring in the course of the disease. This approach could help clinicians build a complete picture of the patient, test the effects of targeted therapies and identify patients who need a more aggressive therapeutic approach to achieve a low risk-status.

Peripheral Arterial Stiffness in Acute Pulmonary Embolism and Pulmonary Hypertension at Short-Term Follow-Up

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe and under-recognized complication of acute pulmonary embolism (PE). Forty consecutive patients with acute PE (Group 1), predominantly female (22, 55%) with a mean age of 69 ± 15 years, were matched for demographic data with 40 healthy subjects (Group 2), 40 systemic hypertension patients (Group 3) and 45 prevalent idiopathic pulmonary arterial hypertension (IPAH) patients (Group 4). The baseline evaluation included physical examination, NYHA/WHO functional class, right heart catheterization (RHC) limited to IPAH patients, echocardiographic assessment and systemic arterial stiffness measurement by cardio-ankle vascular index (CAVI). Patients with PE underwent an echocardiographic evaluation within 1 month from hospital discharge (median 27 days; IQR 21–30) to assess the echo-derived probability of PH. The CAVI values were significantly higher in the PE and IPAH groups compared with the others (Group 1 vs. Group 2, p < 0.001; Group 1 vs. Group 3, p < 0.001; Group 1 vs. Group 4, p = ns; Group 4 vs. Group 2, p < 0.001; Group 4 vs. Group 3, p < 0.001; Group 2 vs. Group 3, p = ns). The predicted probability of echocardiography-derived high-risk criteria of PH increases for any unit increase of CAVI (OR 9.0; C.I.3.9–20.5; p = 0.0001). The PE patients with CAVI ≥ 9.0 at the time of hospital discharge presented an increased probability of PH. This study highlights a possible positive predictive role of CAVI as an early marker for the development of CTEPH.

Right Ventricular Function and Its Coupling With Pulmonary Circulation in Precapillary Pulmonary Hypertension: A Three-Dimensional Echocardiographic Study

Objective: To assess right ventricular (RV) function and RV-pulmonary arterial (PA) coupling by three-dimensions echocardiography and investigate the ability of RV-PA coupling to predict adverse clinical outcomes in patients with precapillary pulmonary hypertension (PH). Methods: We retrospectively collected a longitudinal cohort of 203 consecutive precapillary PH patients. RV volume, RV ejection fraction (RVEF), and RV longitudinal strain (RVLS) were quantitatively determined offline by 3D echocardiography. RV-PA coupling parameters including the RVEF/PA systolic pressure (PASP) ratio, pulmonary arterial compliance (PAC), and total pulmonary resistance (TPR) were recorded. Results: Over a median follow-up period of 20.9 months (interquartile range, 0.1-67.4 months), 87 (42.9%) of 203 patients experienced adverse clinical outcomes. With increasing World Health Organization functional class (WHO-FC), significant trends were observed in increasing RV volume, decreasing RVEF, and worsening RVLS. RV arterial coupling (RVAC) and PAC were lower and TPR was higher for WHO-FC III+IV than WHO-FC I or II. The RVEF/PASP ratio showed a significant correlation with RVLS. RVAC had a stronger correlation with the RVEF/PASP ratio than other indices. Multivariate Cox proportional-hazard analysis identified a lower 3D RVEF and worse RVLS as strong predictors of adverse clinical events. RVAC, TPR, and PAC had varying degrees of predictive value, with optimal cutoff values of 0.74, 11.64, and 1.18, respectively. Conclusions: Precapillary-PH with RV-PA uncoupling as expressed by a RVEF/PASP ratio <0.44 was associated with adverse clinical outcomes. PAC decreased and TPR increased with increasing WHO-FC, with TPR showing better independent predictive value.

Echocardiography in Pulmonary Arterial Hypertension: Is It Time to Reconsider Its Prognostic Utility?

Pulmonary arterial hypertension (PAH) is characterized by an insult in the pulmonary vasculature, with subsequent right ventricular (RV) adaptation to the increased afterload that ultimately leads to RV failure. The awareness of the importance of RV function in PAH has increased considerably because right heart failure is the predominant cause of death in PAH patients. Given its wide availability and reduced cost, echocardiography is of paramount importance in the evaluation of the right heart in PAH. Several echocardiographic parameters have been shown to have prognostic implications in PAH; however, the role of echocardiography in the risk assessment of the PAH patient is limited under the current guidelines. This review discusses the echocardiographic evaluation of the RV in PAH and during therapy, and its prognostic implications, as well as the potential significant role of repeated echocardiographic assessment in the follow-up of patients with PAH.

The Predictive Value of Right Ventricular Longitudinal Strain in Pulmonary Hypertension, Heart Failure, and Valvular Diseases

Right ventricular (RV) systolic function has an important role in the prediction of adverse outcomes, including mortality, in a wide range of cardiovascular (CV) conditions. Because of complex RV geometry and load dependency of the RV functional parameters, conventional echocardiographic parameters such as RV fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE), have limited prognostic power in a large number of patients. RV longitudinal strain overcame the majority of these limitations, as it is angle-independent, less load-dependent, highly reproducible, and measure regional myocardial deformation. It has a high predictive value in patients with pulmonary hypertension, heart failure, congenital heart disease, ischemic heart disease, pulmonary embolism, cardiomyopathies, and valvular disease. It enables detection of subclinical RV damage even when conventional parameters of RV systolic function are in the normal range. Even though cardiac magnetic resonance-derived RV longitudinal strain showed excellent predictive value, echocardiography-derived RV strain remains the method of choice for evaluation of RV mechanics primarily due to high availability. Despite a constantly growing body of evidence that support RV longitudinal strain evaluation in the majority of CV patients, its assessment has not become the part of the routine echocardiographic examination in the majority of echocardiographic laboratories. The aim of this clinical review was to summarize the current data about the predictive value of RV longitudinal strain in patients with pulmonary hypertension, heart failure and valvular heart diseases.

The Growing Role of Echocardiography in Pulmonary Arterial Hypertension Risk Stratification: The Missing Piece

Pulmonary arterial hypertension (PAH) is a rare, progressive disease with a poor prognosis. The pathophysiologic model is mainly characterized by an afterload mismatch in which an increased right ventricle afterload, driven by increased pulmonary vascular resistance (PVR), leads to right heart failure. International guidelines recommend optimization of treatment based on regular risk assessments to achieve or maintain a low-risk status. Current risk scores are based on a multi-modality approach, including demographic, clinical, functional, exercise, laboratory, and hemodynamic parameters, which lack significant echocardiographic parameters. The originality of echocardiography relies on the opportunity to assess in a non-invasive way a physiologically meaningful combination of easy to measure variables tightly related to right ventricle adaptation/maladaptation to increased afterload, the main determinant of a patient's prognosis. Echo-derived morphological and functional parameters have been investigated in PAH, proving to have prognostic relevance. Different therapeutic strategies proved to have different effects in reducing PVR. An upfront combination of drugs, including a parenteral prostacyclin, has shown to be associated with right heart reverse remodeling in a greater proportion of patients than other treatment strategies as a function of PVR reduction. Adding echocardiographic data to current risk scores would allow better identification of right ventricle (RV) adaptation in PAH patients' follow-up. This additional information would allow better stratification of the patient, leading to optimized and personalized therapeutic management.