Echocardiographic features of primary pulmonary hypertension

Chamber Attention Network (CAN): Towards interpretable diagnosis of pulmonary artery hypertension using echocardiography

INTRODUCTION

Accurate identification of pulmonary arterial hypertension (PAH) in primary care and rural areas can be a challenging task. However, recent advancements in computer vision offer the potential for automated systems to detect PAH from echocardiography.

OBJECTIVES

Our aim was to develop a precise and efficient diagnostic model for PAH tailored to the unique requirements of intelligent diagnosis, especially in challenging locales like high-altitude regions.

METHODS

We proposed the Chamber Attention Network (CAN) for PAH identification from echocardiographic images, trained on a dataset comprising 13,912 individual subjects. A convolutional neural network (CNN) for view classification was used to select the clinically relevant apical four chamber (A4C) and parasternal long axis (PLAX) views for PAH diagnosis. To assess the importance of different heart chambers in PAH diagnosis, we developed a novel Chamber Attention Module.

RESULTS

The experimental results demonstrated that: 1) The substantial correspondence between our obtained chamber attention vector and clinical expertise suggested that our model was highly interpretable, potentially uncovering diagnostic insights overlooked by the clinical community. 2) The proposed CAN model exhibited superior image-level accuracy and faster convergence on the internal validation dataset compared to the other four models. Furthermore, our CAN model outperformed the others on the external test dataset, with image-level accuracies of 82.53% and 83.32% for A4C and PLAX, respectively. 3) Implementation of the voting strategy notably enhanced the positive predictive value (PPV) and negative predictive value (NPV) of individual-level classification results, enhancing the reliability of our classification outcomes.

CONCLUSIONS

These findings indicate that CAN is a feasible technique for AI-assisted PAH diagnosis, providing new insights into cardiac structural changes observed in echocardiography.

Bedside Ultrasound for Hemodynamic Monitoring in Cardiac Intensive Care Unit

Thanks to the advances in medical therapy and assist devices, the management of patients hospitalized in cardiac intensive care unit (CICU) is becoming increasingly challenging. In fact, Patients in the cardiac intensive care unit are frequently characterized by dynamic and variable diseases, which may evolve into several clinical phenotypes based on underlying etiology and its complexity. Therefore, the use of noninvasive tools in order to provide a personalized approach to these patients, according to their phenotype, may help to optimize the therapeutic strategies towards the underlying etiology. Echocardiography is the most reliable and feasible bedside method to assess cardiac function repeatedly, assisting clinicians not only in characterizing hemodynamic disorders, but also in helping to guide interventions and monitor response to therapies. Beyond basic echocardiographic parameters, its application has been expanded with the introduction of new tools such as lung ultrasound (LUS), the Venous Excess UltraSound (VexUS) grading system, and the assessment of pulmonary hypertension, which is fundamental to guide oxygen therapy. The aim of this review is to provide an overview on the current knowledge about the pathophysiology and echocardiographic evaluation of perfusion and congestion in patients in CICU, and to provide practical indications for the use of echocardiography across clinical phenotypes and new applications in CICU.

Large animal preclinical investigation into the optimal extracorporeal life support configuration for pulmonary hypertension and right ventricular failure

INTRODUCTION

Right ventricular failure (RVF) is a major cause of mortality in pulmonary hypertension (PH). Mechanical circulatory support holds promise for patients with medically refractory PH, but there are no clinical devices for long-term right ventricular (RV) support. Investigations into optimal device parameters and circuit configurations for PH-induced RVF (PH-RVF) are needed.

METHODS

Eleven sheep underwent previously published chronic PH model. We then evaluated a low-profile, ventricular assist device (VAD)-quality pump combined with a novel low-resistance membrane oxygenator (Pulmonary Assist Device, PAD) under one of four central cannulation strategies: right atrium-to-left atrium (RA-LA, N = 3), RA-to-pulmonary artery (RA-PA, N=3), pumpless pulmonary artery-to-left atrium (PA-LA, N = 2), and RA-to-ascending aorta (RA-Ao, N = 3). Acute-on-chronic RVF (AoC RVF) was induced, and mechanical support was provided for up to 6 hours at blood flow rates of 1 to 3 liter/min. Circuit parameters, physiologic, hemodynamic, and echocardiography data were collected.

RESULTS

The RA-LA configuration achieved blood flow of 3 liter/min. Meanwhile, RA-PA and RA-Ao faced challenges maintaining 3 liter/min of flow due to higher circuit afterload. Pumpless PA-LA was flow-limited due to anatomical limitations inherent to this animal model. RA-LA and RA-Ao demonstrated serial RV unloading with increasing circuit flow, while RA-PA did not. RA-LA also improved left ventricular (LV) and septal geometry by echocardiographic assessment and had the lowest inotropic dependence.

CONCLUSION

RA-LA and RA-Ao configurations unload the RV, while RA-LA also lowers pump speed and inotropic requirements, and improves LV mechanics. RA-PA provide inferior support for PH-RVF, while an alternate animal model is needed to evaluate PA-LA.

Echocardiographic Ventricular Septal Motion Abnormalities are Associated With Pre-Capillary Pulmonary Hypertension in Patients With Preserved Left Ventricular Function

BACKGROUND

Ventricular septal motion abnormalities (VSMA) are common echocardiographic finding in patients with pulmonary hypertension (PHTN). This study sought to evaluate the relationship between echocardiographic findings and the classification of PHTN.

METHODS

This study retrospectively studied 146 consecutive patients referred for right heart catheterisation for clinically suspected PHTN. VSMA were defined as any echocardiographic description of leftward abnormal septal motion or position.

RESULTS

VSMA were present in 42 patients (29%). Patients with VSMA were younger and more likely to have prior pulmonary embolism. They also had less obstructive sleep apnoea, hypertension and dyslipidaemia. By echocardiography, patients with VSMA had lower left ventricular mass, left atrial size and lateral wall E/e' ratio. At cardiac catheterisation, PHTN was confirmed in all (100%) patients with VSMA (compared with 75% in patients without VSMA); 98% with VSMA had elevated pulmonary vascular resistance (compared with 55% without VSMA; p<0.005 for all). VSMA were found to have 91% sensitivity and 51% specificity for the diagnosis of pre-capillary PHTN. On multivariate analysis, VSMA were found to be strong independent predictors for the diagnosis of pre-capillary PHTN (HR, 9.15; 95% CI, 3.0-28.2; p<0.001). Left atrial enlargement was also a strong negative predictor for pre-capillary PHTN (HR, 0.14; 95% CI, 0.05-0.36; p<0.001).

CONCLUSION

Ventricular septal motion abnormalities were strongly associated with pre-capillary PHTN in patients with suspected PHTN. The findings suggest that patients with VSMA should be further evaluated by right heart catheterisation.

Diagnostic utility of sub-maximum cardiopulmonary exercise testing in the ambulatory setting for heart failure with preserved ejection fraction

Pulmonary hypertension is commonly associated with heart failure with preserved ejection fraction. In heart failure with preserved ejection fraction, the elevated left-sided filling pressures result in isolated post-capillary pulmonary hypertension or combined pre- and post-capillary pulmonary hypertension. Although right heart catheterization is the gold standard for diagnosis, it is an invasive test with associated risks. The ability of sub-maximum cardiopulmonary exercise test as an adjunct diagnostic tool in pulmonary hypertension-associated heart failure with preserved ejection fraction is not known. Forty-six patients with heart failure with preserved ejection fraction and pulmonary hypertension (27 patients with combined pre- and post-capillary pulmonary hypertension and 19 patients with isolated post-capillary pulmonary hypertension) underwent sub-maximum cardiopulmonary exercise test followed by right heart catheterization. The study also included 18 age- and gender-matched control subjects. Several sub-maximum gas exchange parameters were examined to determine the ability of sub-maximum cardiopulmonary exercise test to distinguish between isolated post-capillary pulmonary hypertension and combined pre- and post-capillary pulmonary hypertension. Conventional echocardiogram measures did not distinguish between isolated post-capillary pulmonary hypertension and combined pre- and post-capillary pulmonary hypertension. Compared to isolated post-capillary pulmonary hypertension, combined pre- and post-capillary pulmonary hypertension had greater ventilatory equivalent for carbon dioxide (VE/VCO₂) slope, reduced delta end-tidal CO₂ change during exercise, reduced oxygen uptake efficiency slope, and reduced gas exchange determined pulmonary vascular capacitance. The latter was significantly associated with right heart catheterization determined pulmonary artery compliance (r = 0.5; p = 0.0004). On univariate analysis, sub-maximum VE/VCO₂, delta end-tidal carbon dioxide, and gas exchange determined pulmonary vascular capacitance emerged as independent predictors of the extrapolated maximum oxygen uptake (%predicted) (β-coefficient values of –7.32, 95% CI: –13.3 – (–1.32), p = 0.01; 8.01, 95% CI: 1.96–14.05, p = 0.01; 8.78, 95% CI: 2.26–15.29, p = 0.01, respectively). Sub-maximum gas exchange parameters obtained during cardiopulmonary exercise test in an ambulatory setting allows for discrimination between isolated post-capillary pulmonary hypertension and combined pre- and post-capillary pulmonary hypertension. Additionally, sub-maximum cardiopulmonary exercise test derived VE/VCO₂, delta end-tidal carbon dioxide, and gas exchange determined pulmonary vascular capacitance influences aerobic capacity in heart failure with preserved ejection fraction.

Diagnosis of Pulmonary Arterial Hypertension in Children by Using Cardiac Computed Tomography

OBJECTIVE

To establish diagnostic criteria for pulmonary arterial hypertension (PAH) in children by using parameters obtained through noninvasive cardiac computed tomography (CCT).

MATERIALS AND METHODS

We retrospectively measured parameters from CCT images of children from a single institution in a multiple stepwise process. A total of 208 children with mean age of 10.5 years (range: 4 days-18.9 years) were assessed. The variables were classified into three groups: the great arteries; the ventricular walls; and the bilateral ventricular cavities. The relationship between the parameters obtained from the CCT images and mean pulmonary arterial pressure (mPAP) was tested and adjusted by the children's body size. Reference curves for the pulmonary trunk diameter (PTD) and ratio of diameter of pulmonary trunk to ascending aorta (rPTAo) of children with CCT images of normal hearts, adjusted for height, were plotted. Threshold lines were established on the reference curves.

RESULTS

PTD and rPTAo on the CCT images were significantly positively correlated with mPAP (r > 0.85, p < 0.01). Height was the body size parameter most correlated with PTD (r = 0.91, p < 0.01) and rPTAo (r = -0.69, p < 0.01). On the basis of the threshold lines on the reference curves, PTD and rPTAo both showed 88.9% sensitivity for PAH diagnosis, with negative predictive values of 93.3% and 92.9%, respectively.

CONCLUSION

PTD and rPTAo measured from CCT images were significantly correlated with mPAP in children. Reference curves and the formula of PTD and rPTAo adjusted for height could be practical for diagnosing PAH in children.

Pulmonary Artery Acceleration Time in Young Adulthood and Cardiovascular Outcomes Later in Life: The Coronary Artery Risk Development in Young Adults Study

BACKGROUND

Lower pulmonary artery acceleration time (PAcT) is correlated with higher pulmonary artery pressure. The aim of this study was to test the hypothesis that PAcT measured in young adulthood would be associated with future cardiovascular outcomes.

METHODS

In the Coronary Artery Risk Development in Young Adults year 5 examination (1990-1991), PAcT was measured as the time interval from onset to peak flow velocity at the pulmonary valve annulus on Doppler echocardiography. The primary outcome was a composite of fatal or nonfatal cardiovascular disease events: myocardial infarction, non-myocardial infarction acute coronary syndrome, coronary revascularization, congestive heart failure, stroke, transient ischemic attack, carotid artery disease, and peripheral arterial disease.

RESULTS

PAcT was obtained in 4,171 participants (mean age, 30 ± 4 years, 55% women, 51% white). PAcT groups obtained using linear spline methodology were as follows: group I, PAcT ≥ 196 msec (n = 122); group II, PAcT < 196 and ≥115 msec (n = 3,195); and group III, PAcT < 115 msec (n = 854). During follow-up (median, 24.9 years), the primary outcome occurred in 216 participants (5.2%); 66 of 854 (7.7%) of those with PAcT < 115 msec, 149 of 3,195 (4.7%) of those with intermediate PAcT level, and one of 122 (0.8%) of those with PAcT ≥ 196 msec. In a fully adjusted model, the lowest and intermediate PAcT groups had hazard ratios of 8.3 (95% CI, 1.1-62.1; P = .04) and 6.8 (95% CI, 0.9-50.5; P = .06), respectively, in comparison with the highest PAcT group.

CONCLUSIONS

PAcT is useful for better identifying young adults at higher risk for cardiovascular events, who may benefit from a strict control of modifiable cardiovascular risk factors.

Invasive and Noninvasive Evaluation for the Diagnosis of Pulmonary Hypertension: How to Use and How to Combine Them

The etiologic diagnosis of pulmonary hypertension (PH) may be very challenging. Right-heart catheterization (RHC) in isolation cannot classify a precapillary PH patient into group 1, 3, 4, or 5. Moreover, RHC may be not sufficient for reaching a definitive differential diagnosis of precapillary or postcapillary PH if hemodynamic data are not integrated in clinical context and combined with information gleaned from noninvasive imaging. Therefore, only the integration of risk factors, clinical evaluation, invasive and noninvasive tests allows the physician to distinguish between different forms of PH.

Tricuspid annular plane systolic excursion is preserved in young patients with pulmonary hypertension except when associated with repaired congenital heart disease

Aims

Tricuspid annular plane systolic excursion (TAPSE) is a measure of right ventricular (RV) longitudinal function that correlates with functional status and mortality in adults with pulmonary hypertension (PH). The diagnostic and predictive value of TAPSE in children with PH has not been fully examined. We aimed to define TAPSE across aetiologies of paediatric PH and assess the correlation between TAPSE and measures of disease severity.

Methods and results

TAPSE measurements were obtained in 84 children and young adults undergoing treatment for PH and 315 healthy children to establish z-scores at moderate altitude for comparison. The relationships between TAPSE and echocardiographic, biomarker, and functional measures of disease severity between aetiologies were assessed. TAPSE z-scores in PH patients with congenital heart disease (CHD) repaired with open cardiac surgery (n = 20, mean -2.73) were significantly decreased compared with normal children and patients with other aetiologies of PH (P < 0.001) but did not reflect poorer clinical status. TAPSE z-scores in children with idiopathic PH (n = 29, -0.41), unrepaired CHD (n = 11, -0.1), and PH related to systemic disease (n = 14, -0.39) were not different from normal. TAPSE correlated modestly with brain natriuretic peptide, echocardiographic function parameters, and functional class except in patients with repaired CHD.

Conclusion

Children with PH maintain normal TAPSE values early except when associated with repaired CHD. Superior RV adaptation to high afterload in children compared with adults may account for this finding. Reduced TAPSE after repair of CHD does not correlate with functional status and may reflect post-operative changes rather than poor function primarily due to PH.

The prognostic significance of tricuspid valve regurgitation in pulmonary arterial hypertension

INTRODUCTION

Tricuspid valve regurgitation (TR) is a frequent finding in patients with pulmonary arterial hypertension (PAH). However, its prognostic significance and relation to PAH, while suspected, are poorly understood. We assessed 727 consecutive patients with newly diagnosed PAH who underwent transthoracic echocardiographic evaluation of tricuspid valve function.

OBJECTIVES

The study objective was to determine the association of TR presence and severity with patient characteristics, pulmonary artery hemodynamics and outcome.

METHODS

Consecutive patients with newly diagnosed PAH (N = 727 with group 1 pulmonary hypertension) underwent transthoracic echocardiographic evaluation of tricuspid valve function at diagnosis. The primary study end point was all-cause mortality or lung transplantation.

RESULTS

In this population, 702 patients (96.5%) had TR; in 165 patients (23%), TR was severe. Compared with those with no or mild TR by echocardiography criteria, patients with severe TR had shorter mean (SD) 6-minute walk distances (285 [125] m vs 360 [121] m; P = .02) and higher levels of B-type natriuretic peptide (695 [672] pg/dL vs 328 [300] pg/dL; P < .05). Severe TR was associated with greater right atrial dilatation (91% vs 47%; P = .004) and right ventricular (RV) dilatation (92% vs 51%; P = .008), greater right atrial pressure (mean [SD] 15 [7] mm Hg vs 10 [6] mm Hg; P < .001) and lower cardiac index (mean [SD], 2.2 [0.7] L/min/m2 vs 2.8 [0.9] L/min/m2; P < .001). Severe TR was strongly predictive of greater 5-year mortality risk after adjustment for age, sex, functional class, 6-minute walk distance, diffusing capacity, RV size and pulmonary vascular resistance index (adjusted hazard ratio, 1.83; 95% CI, 1.38-2.41; P < .001).

CONCLUSIONS

Severe TR was a significant predictor of long-term mortality rate in PAH, and TR severity correlated with PAH severity.

Pulmonary Arterial Hypertension in Women

Pulmonary arterial hypertension (PAH) is characterized by pathological hemodynamic elevation in pulmonary artery pressure. Development of international registries over the last decade has raised awareness about the disease, leading to the development of new and improved therapies. Paradigm shifts such as these warrant review of existing literature regarding PAH, especially in females, as the disease continues to affect women more than males. The aim of this review is to provide an update on the classification, pathophysiology, diagnosis, and treatment of PAH while focusing specifically on its impact on women.

Comparison of change in end tidal carbon dioxide after three minutes of step exercise between systemic sclerosis patients with and without pulmonary hypertension

OBJECTIVES

Pulmonary hypertension (PH) is an important cause of morbidity and mortality in patients with SSc. The submaximal heart and pulmonary evaluation (step test) is a non-invasive, submaximal stress test that could be used to identify SSc patients with PH. Our aims were to determine whether change in end tidal carbon dioxide ([Formula: see text]) from rest to end-exercise, and the minute ventilation to carbon dioxide production ratio ([Formula: see text]), both as measured by the step test, differ between SSc patients with and without PH. We also examined differences in validated self-report questionnaires and potential PH biomarkers between SSc patients with and without PH.

METHODS

We performed a cross-sectional study of 27 patients with limited or dcSSc who underwent a right heart catheterization within 24 months prior to study entry. The study visit consisted of questionnaire completion; history; physical examination; step test performance; and phlebotomy. [Formula: see text], [Formula: see text], self-report data and biomarkers were compared between patients with and without PH.

RESULTS

SSc patients with PH had a statistically significantly lower median (interquartile range) [Formula: see text] than SSc patients without PH [-2.1 (-5.1 to 0.7) vs 1.2 (-0.7 to 5.4) mmHg, P = 0.035], and a statistically significantly higher median (interquartile range) [Formula: see text] [53.4 (39-64.1) vs 36.4 (31.9-41.1), P = 0.035]. There were no statistically significant differences in self-report data or biomarkers between groups.

CONCLUSION

[Formula: see text] and [Formula: see text] as measured by the step test are statistically significantly different between SSc patients with and without PH. [Formula: see text] and [Formula: see text] may be useful screening tools for PH in the SSc population.

Plasma atrial natriuretic peptide and N-terminal pro B-type natriuretic peptide concentrations in dogs with right-sided congestive heart failure

The clinical utility of plasma natriuretic peptide concentrations in dogs with right-sided congestive heart failure (CHF) remains unclear. We investigated whether plasma levels of atrial natriuretic peptide (ANP) and N-terminal pro B-type natriuretic peptide (NT-proBNP) are useful for assessing the congestive signs of right-sided heart failure in dogs. This retrospective study enrolled 16 healthy dogs and 51 untreated dogs with presence (n=28) or absence (n=23) of right-sided CHF. Medical records of physical examinations, thoracic radiography and echocardiography were reviewed. The plasma concentration of canine ANP was measured with a chemiluminescent enzyme immunoassay. Plasma NT-proBNP concentrations were determined using an enzyme immunoassay. Plasma ANP and NT-proBNP concentrations in dogs with right-sided CHF were significantly higher than in healthy controls and those without right-sided CHF. The plasma NT-proBNP concentration >3,003 pmol/l used to identify right-sided CHF had a sensitivity of 88.5% and specificity of 90.3%. An area under the ROC curve (AUC) was 0.93. The AUC for NT-proBNP was significantly higher than the AUCs for the cardiothoracic ratio, vertebral heart score, ratio of right ventricular end-diastolic internal diameter to body surface area, tricuspid late diastolic flow and ratio of the velocities of tricuspid early to late diastolic flow. These results suggest that plasma ANP and NT-proBNP concentrations increase markedly in dogs with right-sided CHF. Particularly, NT-proBNP is simple and helpful biomarkers to assess the right-sided CHF.

Right Atrial Function in Pulmonary Arterial Hypertension

BACKGROUND

Elevated right atrial (RA) pressure is an established prognostic measure in pulmonary arterial hypertension (PAH). However, little is known about perturbations in RA function in PAH.

METHODS AND RESULTS

Reservoir (RA longitudinal strain [RA LS]), conduit (RA early LS rate), and active (RA late LS rate) phases were assessed by 2D speckle tracking in 65 patients with PAH, 6-minute walk distance ≤450 m, and a pulmonary vascular resistance >800 dynes·s/cm(5), despite therapy with at least 2 PAH-specific medications enrolled in the Imatinib in Pulmonary Arterial Hypertension, a Randomized Efficacy Study (IMPRES) trial and were compared with 30 healthy controls of similar age and sex. We studied the association of RA functional measures with invasive pulmonary hemodynamics, cardiac structure and function, and N-terminal pro brain natriuretic peptide. RA LS and early LS rate were reduced in PAH patients compared with controls (27.1±11.6 versus 56.9±12.7, adjusted P<0.001 and -0.6±0.5 versus -1.5±0.5, adjusted P<0.001, respectively) even after adjusting for RA area and invasive RA pressure, whereas RA late LS rate was similar between groups (-1.4±0.7 versus -1.5±0.4, P=0.42). Among PAH patients, worse RA LS correlated with greater RA size (r=-0.50, P<0.0001) and pressure (r=-0.37, P=0.002), but not pulmonary artery pressure (r=-0.07, P=0.58). Worse RA LS was also associated with right ventricular enlargement and dysfunction and higher N-terminal pro brain natriuretic peptide independent of RA size and pressure.

CONCLUSIONS

RA reservoir and passive conduit functions are impaired in PAH, independent of RA size and pressure, and likely reflect right ventricular failure and overload.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00902174.

Essential echocardiographic evaluation in patients with suspected pulmonary hypertension: an overview for the practicing physician

Prompt and accurate diagnosis of patients presenting with symptoms suggestive of pulmonary arterial hypertension (PAH) is of outmost importance as delays in identifying this clinical entity have detrimental effects on both morbidity and mortality. Initial noninvasive assessment of these patients has traditionally included a number of routine tests of which transthoracic echocardiography (TTE) has been shown to either confirm the presence of structural anomalies of the right ventricle (RV) indicative of PAH or exclude other potential causes of pulmonary hypertension (PH). Consequently, TTE has become a well-validated and readily available imaging tool not only used for this initial screening but also for routine follow-up of PH patients. Since chronic PH is known to unbalance the normal hemodynamic and mechanical homeostatic interaction between the RV and pulmonary circulation; the resulting response is that of an abnormal RV remodeling, clinically translated into progressive RV hypertrophy and dilatation. An enlarged and hypertrophied RV not only would eventually lose effective contractility but also this gradual decline in RV systolic function is the main abnormality in determining adverse clinical outcomes. Therefore, it is of outmost importance that TTE examination be comprehensive but most importantly accurate and reproducible. This review aims to highlight the most important objective measures that can be routinely employed, without added complexity, that will certainly enhance the interpretation and advance our understanding of the hemodynamic and mechanical abnormalities that PH exerts on the RV.

Pediatric Pulmonary Hypertension: Guidelines From the American Heart Association and American Thoracic Society

Pulmonary hypertension is associated with diverse cardiac, pulmonary, and systemic diseases in neonates, infants, and older children and contributes to significant morbidity and mortality. However, current approaches to caring for pediatric patients with pulmonary hypertension have been limited by the lack of consensus guidelines from experts in the field. In a joint effort from the American Heart Association and American Thoracic Society, a panel of experienced clinicians and clinician-scientists was assembled to review the current literature and to make recommendations on the diagnosis, evaluation, and treatment of pediatric pulmonary hypertension. This publication presents the results of extensive literature reviews, discussions, and formal scoring of recommendations for the care of children with pulmonary hypertension.

Impact of lowering pulmonary vascular resistance on right and left ventricular deformation in pulmonary arterial hypertension

AIMS

As pulmonary arterial hypertension (PAH) is associated with significant morbidity and mortality, particularly among patients with right ventricular (RV) dysfunction, we aimed to determine the impact of therapy to reduce pulmonary vascular resistance (PVR) on RV and LV deformation in PAH.

METHODS AND RESULTS

Right ventricular free wall longitudinal strain (FWLS) and LV global circumferential strain (CS) were measured at baseline, 12 weeks, and 24 weeks in 68 patients with advanced PAH randomized to imatinib or placebo in the Imatinib in Pulmonary arterial hypertension, a Randomized Efficacy Study (IMPRES) trial, and compared with 30 healthy controls. Compared with controls, PAH was associated with impaired RV FWLS (-15.9 ± 5.4 vs. -30.8 ± 4.3, respectively; P < 0.0001) and LV septal CS (-24.2 ± 8.2 vs. -31.4 ± 5.3, respectively, P < 0.0001), but not LV global CS. Improvement in PVR and mean pulmonary artery pressure (MPAP) over a 24-week period was significantly associated with improvement in RV FWLS (r = 0.39, P = 0.02; 0.33, P = 0.04 respectively), LV global CS (r = 0.61, P = 0.0001; r = 0.60, P = 0.0001, respectively), and LV septal CS (r = 0.50, P = 0.005; r = 0.56, P = 0.002, respectively). These associations were most robust with LV global and septal CS. Imatinib therapy was associated with improvement in RV FWLS compared with placebo.

CONCLUSIONS

PAH is associated with impaired biventricular deformation. Reduction in PVR is associated with improvements in both RV and LV deformation, coupled to improvements in MPAP and stroke volume index, with LV global and septal CS the strongest correlates of these changes. RV FWLS is sensitive to treatment effect, demonstrating greater improvement with imatinib compared with placebo.

TRIAL REGISTRATION

NCT00902174.

Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation

Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged exposure in Sherpa, a highly adapted HA population. To investigate short-term adaptation and potential long-term cardiac remodeling, we studied ventricular structure and function in Sherpa at 5,050 m (n = 11; 31 ± 13 yr; mass 68 ± 10 kg; height 169 ± 6 cm) and lowlanders at sea level (SL) and following 10 ± 3 days at 5,050 m (n = 9; 34 ± 7 yr; mass 82 ± 10 kg; height 177 ± 6 cm) using conventional and speckle-tracking echocardiography. At HA, PASP was higher in Sherpa and lowlanders compared with lowlanders at SL (both P < 0.05). Sherpa had smaller right-ventricular (RV) and LV stroke volumes than lowlanders at SL with lower RV systolic strain (P < 0.05) but similar LV systolic mechanics. In contrast to LV systolic mechanics, LV diastolic, untwisting velocity was significantly lower in Sherpa compared with lowlanders at both SL and HA. After partial acclimatization, lowlanders demonstrated no change in the RV end-diastolic area; however, both RV strain and LV end-diastolic volume were reduced. In conclusion, short-term hypoxia induced a reduction in RV systolic function that was also evident in Sherpa following chronic exposure. We propose that this was consequent to a persistently higher PASP. In contrast to the RV, remodeling of LV volumes and normalization of systolic mechanics indicate structural and functional adaptation to HA. However, altered LV diastolic relaxation after chronic hypoxic exposure may reflect differential remodeling of systolic and diastolic LV function.

WHO's in second?: A practical review of World Health Organization group 2 pulmonary hypertension

World Health Organization (WHO) group 2 pulmonary hypertension (PH) due to left-side heart disease (ie, heart failure or left-sided valvular heart disease) is the most common form of PH in western countries. Distinguishing patients with WHO group 2 PH, particularly the subset of patients with PH due to heart failure with preserved ejection fraction (HFpEF), from those with WHO group 1 pulmonary arterial hypertension (PAH) is challenging. Separating the two conditions is of vital importance because treatment strategies differ completely. Furthermore, therapies that are indicated for WHO group 1 PAH may be harmful in patients with WHO group 2 PH. We review the somewhat confusing PH nomenclature and the WHO classification system and rationale behind it. We then focus on left-side heart disorders that cause PH. An aging population and advances in the medical management of common cardiovascular disorders have caused the prevalence of heart failure to rise significantly, with more than one-half of patients having HFpEF. We review contemporary studies that focus on clinical and echocardiographic findings that help to distinguish HFpEF from PAH in the patient with PH. We discuss the typical, and sometimes atypical, hemodynamic profiles that characterize these two groups, review challenges in the interpretation of data obtained by right-sided heart catheterization, and highlight special maneuvers that may be required for accurate diagnosis. Finally, we review the largely disappointing studies on the use of PAH-specific therapies in patients with WHO group 2 PH, including the use of prostacyclins, endothelin receptor antagonists, and the more promising phosphodiesterase-5 inhibitors.

Pericardial effusions in pulmonary arterial hypertension: characteristics, prognosis, and role of drainage

BACKGROUND

The presence and size of a pericardial effusion in pulmonary arterial hypertension (PAH) and its association with outcome is unclear.

METHODS

In this single-center cohort study of 577 patients with group 1 PAH seen between January 1, 1995, and December 31, 2005, all patients underwent transthoracic echocardiography and were followed for ≥ 5 years. Echocardiography-guided pericardiocentesis was performed as needed.

RESULTS

Pericardial effusions on index echocardiography occurred in 150 patients (26%); 128 patients had small and 22 had moderate-sized or larger effusions. Most of the moderate or greater effusions occurred in patients who had connective tissue disease (82%). Mean right atrial pressure was 13.4 ± 4.4 mm Hg (no effusion), 15.1 ± 4.4 mm Hg (small effusion), and 17.0 ± 4.0 mm Hg (moderate or greater effusion) (P &lt; .0001). Median survival for patients with moderate or greater effusion, mild effusion, or no effusion was 11.3 months, 42.3 months, and 76.5 months, respectively. Four of the 22 patients with moderate or greater pericardial effusions eventually required echocardiography-guided pericardiocentesis because of clinical and echocardiographic evidence of hemodynamic impact. When drained, the effusions were large (858 ± 469 mL) and generally serous. All pericardiocenteses were performed cautiously under echocardiographic guidance by a highly experienced echocardiologist, with low immediate morbidity and mortality.

CONCLUSIONS

Pericardial effusions are relatively common but rarely of hemodynamic significance in patients with PAH. However, even modest degrees of pericardial fluid are associated with a significant increase in mortality and appear to reflect the presence of associated collagen vascular disease and high right atrial pressure.

Submaximal heart and pulmonary evaluation: a novel noninvasive test to identify pulmonary hypertension in patients with systemic sclerosis

OBJECTIVE

Pulmonary hypertension (PH) is a leading cause of death in patients with systemic sclerosis (SSc; scleroderma). Although right-sided heart catheterization (RHC) is the gold standard for diagnosing PH, it is an invasive test with associated risks. The submaximal heart and pulmonary evaluation (step test) is a noninvasive, submaximal stress test that could be used to identify patients with PH. The purpose of this study is to assess the correlation between change in end tidal carbon dioxide (ΔPETCO2 ) from rest to end-exercise on the step test and mean pulmonary artery pressure (mPAP) on RHC in SSc patients.

METHODS

This is a retrospective cohort study of patients with limited or diffuse cutaneous SSc who were evaluated in an academic cardiology practice between November 2007 and November 2011 and underwent a step test and RHC. Statistical analysis was performed using Spearman's correlation test and multivariable linear regression.

RESULTS

A total of 679 charts were reviewed. Nineteen SSc patients who underwent a step test and RHC were included. ΔPETCO2 was negatively correlated with mPAP (r = -0.82, P < 0.0001). In a multivariable linear regression model evaluating the relationship between ΔPETCO2 and mPAP, controlling for age, sex, and time between and order of step test and RHC, ΔPETCO2 remained the only variable statistically significantly associated with mPAP (P < 0.001). The step test had a sensitivity of 100%, specificity of 75%, positive predictive value of 93.8%, and negative predictive value of 100% for the diagnosis of PH.

CONCLUSION

ΔPETCO2 on the step test has a strong, statistically significant negative correlation with mPAP on RHC.

Pericardial effusion in pulmonary arterial hypertension

Abstract Pulmonary arterial hypertension (PAH) is a serious condition that can lead to right heart failure and death. Pericardial effusion in PAH is associated with significant morbidity and mortality, and its pathogenesis is complex and poorly understood. There are few data on the prevalence of pericardial effusion in PAH, and more importantly, the management of pericardial effusion is controversial. Current literature abounds with case reports, case series, and retrospective studies that have limited value for assessing this association. Hence, we summarize the available evidence on this ominous association and identify areas for future research.

Diagnosis of pulmonary arterial hypertension

Accurate diagnosis of pulmonary arterial hypertension can be challenging and often requires a high index of clinical suspicion. Use of a variety of noninvasive tests can help define the population of patients in whom invasive cardiac catheterization should be pursued. An understanding of the historical, physical exam, electrocardiographic, radiographic, and echocardiographic clues in the diagnosis is important. A ventilation-perfusion scan and careful assessment for left-to-right shunting are mandatory to avoid missing reasons for pulmonary hypertension that may require nonpharmacologic management. Right heart, and sometimes concomitant left heart, catheterization is required to establish the diagnosis and distinguish pulmonary arterial from pulmonary venous hypertension.

Echocardiography in pulmonary arterial hypertension: from diagnosis to prognosis

Pulmonary arterial hypertension is most often diagnosed in its advanced stages because of the nonspecific nature of early symptoms and signs. Although clinical assessment is essential when evaluating patients with suspected pulmonary arterial hypertension, echocardiography is a key screening tool in the diagnostic algorithm. It provides an estimate of pulmonary artery pressure, either at rest or during exercise, and is useful in ruling out secondary causes of pulmonary hypertension. In addition, echocardiography is valuable in assessing prognosis and treatment options, monitoring the efficacy of specific therapeutic interventions, and detecting the preclinical stages of disease.

Echocardiography in pulmonary arterial hypertension

In the context of pulmonary arterial hypertension (PAH), echocardiographic assessment of right ventricular (RV) function is key to determining disease severity and prognosis. Using Doppler echocardiography (ECHO) there are numerous ways that RV function can be measured, either directly or indirectly, to capture the triad of changes in RV geometry, right-to-left interaction, and RV systolic dysfunction in response to high pulmonary vascular resistance states, such as PAH. To fully evaluate and characterize the nature and extent of the impact of PAH on the RV in an individual patient, it is critical to assess a combination of these direct and indirect measures of RV function. In order to predict changes in status and have prognostic significance, the variables used must be easy to measure, reproducible, and clinically relevant. This review assesses the relative value of different ECHO parameters and looks at what the future holds for ECHO imaging of the right heart in PAH.

Diagnostic utility of NT-proBNP and ANP in a canine model of chronic embolic pulmonary hypertension

The information needed to diagnose pulmonary arterial hypertension (PAH) in dogs based on N-terminal pro B-type natriuretic peptide (NT-proBNP) and atrial natriuretic peptide (ANP) levels is unclear. In this study, serial changes in plasma NT-proBNP and ANP concentrations were evaluated in association with the development of chronic embolic pulmonary hypertension (CEPH). Six Beagle dogs underwent percutaneous pulmonary artery catheterization. CEPH was induced by the repeated injection of 300 μm microspheres into the pulmonary artery via the catheter. Measured peak systolic pulmonary arterial pressure (PAPs) was elevated up to 80 mm Hg at 90 days by repeated injection of microspheres. Echocardiographic examination showed significant increase in the main pulmonary artery enlargement, right ventricular dilation, transtricuspid late diastolic flow, and ventricular late diastolic myocardial velocity. Plasma concentrations of NT-proBNP and ANP were significantly increased by microsphere-induced severe CEPH, but not by mild CEPH. Measured PAPs correlated weakly with plasma NT-proBNP and ANP concentrations (r=0.63 and 0.69, respectively) and with several echocardiographic variables. Our results indicated that plasma ANP and NT-proBNP responded to severe PAH, but that they were not sensitive for mild PAH.

Temporal differences in ejection between right and left ventricles in chronic pulmonary hypertension: a pulsed Doppler study

Chronic pulmonary hypertension (cPH) is known to alter right ventricular (RV) deformation and cause mechanical dyssynchrony. Since not all echocardiographic laboratories are equipped with sophisticated imaging tools, we decided to determine if Doppler would be useful to detect temporal differences between the ejection of the right and left ventricle (LV) as a result of cPH using pulsed outflow tract (RVOT and LVOT) spectral signals. Data was collected from 30 patients without PH (Group I: 53 ± 7 years and 31 ± 5 mmHg) and from 40 patients with cPH (Group II: 53 ± 13 years; P = NS and 82 ± 24 mmHg; P < 0.00001). Group II patients had a longer temporal delay from onset between RVOT and LVOT (23 ± 12 ms vs. 0 ± 0 ms; P < 0.0001) with a significantly shorter temporal difference between RVOT and LVOT spectral signals to reach maximum peak of ejection (27 ± 24 ms vs. 61 ± 23 ms; P < 0.0001) than Group I. In addition, Group II had a statistically lower RVOT VTI value (0.14 ± 0.05 cm vs. 0.17 ± 0.03 cm; P < 0.01). Our data seems to suggest that increasing severity of PH mainly affects ejection of the RV resulting in noticeable temporal alterations in both time of onset as well as time to reach maximum peak ejection between RV and LV. More studies are now required to determine the utility of obtaining these measurements prospectively in the follow-up and treatment of cPH patients.

Diagnosis and assessment of pulmonary vascular disease by Doppler echocardiography

Pulmonary hypertension (PH) is a relatively misunderstood disease, partly related to the fact that many perceive PH to be a singular diagnosis. An unintended consequence of this is the misapplication of the role of the Doppler-Echocardiographic (DE) examination, as well as an underappreciation for its ability to help discern PH pathophysiology prior to right heart catheterization. Since DE often serves as the "gatekeeper" to invasive right heart catheterization, misinterpretation of the DE can lead to missed or delayed diagnosis with devastating consequences. Too often, the primary or nearly exclusive focus of the DE examination is placed on the pulmonary artery pressure estimation. Two main issues with this approach are that Doppler pressure estimations can be inaccurate and even when accurate, without integration of additional 2-D and Doppler information, the clinician will often still not appreciate the pathophysiology of the PH nor its clinical significance. This review will focus on the 2-D and Doppler features necessary to assess pulmonary vascular disease (PVD), discern the salient differences between PVD and pulmonary venous hypertension (PVH), and how to integrate these key DE parameters such that PH pathophysiology can be determined noninvasively and early in the patient workup. Overreliance on any single DE metric, and especially PA pressure estimation, detracts from the overall diagnostic potential of the DE examination. Integrating the relative balance of right and left heart findings, along with proper Doppler interpretation provides a wealth of clinical and pathophysiologic insight prior to invasive hemodynamic assessment. The end results are heightened awareness and improved identification of which patients should be referred for further invasive testing, as well the use of the DE information to compliment the findings from invasive testing.

The role of imaging techniques in the assessment of pulmonary circulation

Knowledge of the structure and function of pulmonary circulation has evolved considerably in the last few decades. The use of non-invasive imaging techniques to assess the anatomy and function of the pulmonary vessels and heart has taken on added importance with the recent advent of novel therapies. Imaging findings not only constitute a diagnostic tool but have also proven to be essential for prognosis and treatment follow-up. This article reviews the myriad of imaging methods currently available for the assessment of pulmonary circulation, from the simple chest X-ray to techniques that are more complex and promising, such as electrical impedance tomography.

The effect of chronic pulmonary hypertension on diastolic annular tissue velocities: a pilot study

BACKGROUND

Tissue Doppler imaging (TDI) of mitral (MA) and tricuspid annular (TA) events has been shown to describe systolic and diastolic properties of each respective ventricle. However, the effect of chronic elevations in pulmonary artery systolic pressure (PASP) on individual diastolic annular velocities has not been well characterized.

METHODS

Measurements of left (LV) and right ventricular (RV) performance and TDI of the lateral MA and TA to measure systolic and early and late diastolic velocities were recorded from 50 individuals (group I: mean age was 56 ± 15 years and mean PASP of 29 ± 6 mm Hg) and from 50 patients (group II: mean age was 55 ± 14 years and mean PASP of 83 ± 27 mm Hg).

RESULTS

Group II patients had worse parameters of RV performance whereas LV systolic function remained unaffected when compared with group I. Group II had lower TA early velocities (0.09 ± 0.04 m/sec versus 0.12 ± 0.03 m/sec; P < 0.0001) with higher late diastolic MA velocities (0.12 ± 0.04 m/sec versus 0.10 ± 0.03 m/sec; P < 0.002) than group I. MA late diastolic velocity (P < 0.02) was the most useful in identifying elevated PASP and early diastolic TA velocity (P < 0.01) in identifying abnormal right ventricular fractional area change.

CONCLUSION

Chronic pulmonary hypertension seems to selectively affect TDI annular diastolic velocities of both ventricles in different ways. Additional studies are needed to correlate changes in annular TDI velocities with symptoms and clinical outcomes in chronic pulmonary hypertension.

Regional left ventricular systolic function and the right ventricle: the multi-ethnic study of atherosclerosis right ventricle study

BACKGROUND

Dysfunction of the interventricular septum has been implicated in right ventricular (RV) failure. However, little is known about the relationship between ventricular septal and RV function in patients without clinical cardiovascular disease. We hypothesized that better septal function would be associated with higher RV ejection fraction and lower RV mass and volume by cardiac MRI.

METHODS

In the Multi-Ethnic Study of Atherosclerosis (MESA), cardiac MRI was performed on community-based participants without clinical cardiovascular disease. Images were analyzed by the harmonic phase method to measure peak circumferential systolic midventricular strain for each wall (anterior, lateral, inferior, and septal). Multivariable linear regression and generalized additive models were used to assess the relationship between septal strain and RV morphology.

RESULTS

There were 917 participants (45.7% women) with a mean age of 65.7 years. Better septal function was associated with higher RV ejection fraction in a nonlinear fashion after adjustment for all covariates (P = .03). There appeared to be a threshold effect for the contribution of septal strain to RV systolic function, with an almost linear decrement in RV ejection fraction with septal strain from -18% to -10%. Septal function was not related to RV mass or volume.

CONCLUSIONS

Interventricular septal function was linked to RV systolic function independent of other left ventricular regions, even in individuals without clinical cardiovascular disease. This finding confirms animal and human research suggesting the importance of septal function to the right ventricle and implies that changes in septal function could herald RV dysfunction.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00005487; URL: www.clinicaltrials.gov.

Echocardiographic Assessment of Left Ventricular Diastolic Dysfunction: Differentiating a Pulmonary Vascular From a Pulmonary Venous Origin of Pulmonary Hypertension

Pulmonary hypertension (PH) is a heterogeneous condition that may be due to a primary pulmonary arteriolar vasculopathy (pulmonary arterial hypertension or PAH: Group I), or secondary to left heart disease and pulmonary venous hypertension (PVH: Group II), chronic respiratory conditions (Group III), chronic thromboembolic disease (CTEPH: Group IV) or miscellaneous/multifactorial causes (Group V).12 The clinical diagnoses themselves are as diverse as the varied hemodynamic compositions of PH. Pulmonary hypertension ultimately results from varying interactions between pulmonary blood flow, pulmonary vascular resistance (PVR), conduit vessel compliance, and downstream left atrial (LA) pressure. Therefore, PH may also result from abnormalities in one or more of these factors. Patients with PAH, CTEPH, and most Group III patients have a “precapillary” hemodynamic profile with a normal LA pressure and an increased PVR as the primary mechanism of their PH. In contrast, patients with PVH (“postcapillary”) have increased LA pressure, most often with a normal or only mildly elevated PVR.

Accuracy of noninvasively determined pulmonary artery systolic pressure

The noninvasive estimation of pulmonary artery systolic pressure (PASP) has become a standard component of the echocardiographic examination. Our aim was to evaluate the accuracy of this modality in a large series of unselected studies obtained in clinical practice. All right heart catheterizations during a 4-year period were reviewed. Studies with echocardiographic findings available within 48 hours were evaluated for PASP agreement. In an effort to mirror clinical practice, the right heart catheterization findings were used as the reference standard and the PASP values were taken directly from the respective clinical reports. Overall, 792 right heart catheterization-echocardiogram pairs were identified. Echocardiographic PASP could not be estimated in 174 of these studies (22.0%). The correlation between modalities was moderate, but agreement was poor (bias 9.0%, 95% limits of agreement -53.2% to 71.2%, r = 0.52, p <0.001). Misclassification of clinical PASP categories occurred more often than not (54.4%). Multivariate analysis using multiple potential sources of error could only account for 3.2% of the total variation in the discrepancy between the study modalities (p = 0.003). In conclusion, noninvasively estimated PASP had limited agreement with the invasively determined PASP, and misclassification of PASP clinical categories occurred frequently. Given the widespread use of echocardiographically determined PASP, these data are in need of replication in a large prospective study.

Review of Movahed's sign (D shaped left ventricle seen on gated SPECT) suggestive of right ventricular overload

Recently, D shaped ventricle seen on gated SPECT imaging (Movahed's sign) has shown to correlate with right ventricular overload similar to the D shape ventricle seen on echocardiography. Right ventricle (RV) imaging during gated SPECT studies is challenging because of the low tracer uptake due to relatively smaller right ventricular myocardial mass and lower coronary flow to the RV. Increased mass or workload causes higher tracer uptake in the RV wall secondary to increase in RV wall thickness and higher coronary flow. Furthermore, increased RV volume or pressure load can cause displacement of the septum towards the left ventricle causing septal flattening and a D shaped configuration of the left ventricular septum. This is an important finding that should be a part of nuclear gated SPECT interpretation.