The diagnostic accuracy of Doppler echocardiography in assessment of pulmonary artery systolic pressure: a meta-analysis

Obstructive Sleep Apnea, Obesity Hypoventilation Syndrome, and Pulmonary Hypertension: A State-of-the-Art Review

The pathophysiological interplay between sleep-disordered breathing (SDB) and pulmonary hypertension (PH) is complex and can involve a variety of mechanisms by which SDB can worsen PH. These mechanistic pathways include wide swings in intrathoracic pressure while breathing against an occluded upper airway, intermittent and/or sustained hypoxemia, acute and/or chronic hypercapnia, and obesity. In this review, we discuss how the downstream consequences of SDB can adversely impact PH, the challenges in accurately diagnosing and classifying PH in the severely obese, and review the limited literature assessing the effect of treating obesity, obstructive sleep apnea, and obesity hypoventilation syndrome on PH.

Patient and Therapeutic Profiles of Pulmonary Hypertension in Chronic Lung Diseases in Japan: A Cohort Study Using a Claims Database

INTRODUCTION

Pulmonary hypertension (PH) is often complicated by chronic lung diseases (CLDs) such as chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD). Differentiating between PH associated with CLD (group 3 PH) and pulmonary arterial hypertension (PAH) in CLD is often difficult and reporting on the efficacy of PAH-specific therapies is inconsistent as a result of the lack of understanding of the heterogeneity of patients with PH.

METHODS

A retrospective observational cohort study was conducted to understand the baseline characteristics, comorbidities, and treatment profiles of patients with PH in CLD in a real-world setting using a large-scale claims database (Medical Data Vision). Administrative and clinical data for patients admitted to acute-care hospitals in Japan between April 2008 and January 2021 were analyzed.

RESULTS

A total of 115,921 patients with CLD (109,578 with COPD and 6343 with ILD, of whom 569 and 176 had PH, respectively) were analyzed. This study found lower PH diagnosis rates among patients with COPD and patients with ILD than in previous studies. The majority of PH with CLD patients were elderly (mean age 75.7 years) and male (80.81%). Among patients with CLD prescribed PAH-specific therapies (105 patients with COPD; 64 patients with ILD), most received these as monotherapy (COPD, 84.76%; ILD, 75.56%); the most common were phosphodiesterase 5 inhibitors (COPD, 42.70%; ILD, 18.37%), prostacyclins (oral; COPD, 48.31%; ILD, 24.49%), and endothelin receptor antagonists (ERA) (COPD, 8.99%; ILD, 18.37%). Comorbidities (e.g., pulmonary, cardiac, kidney), home oxygen therapy (HOT), and echocardiography (ECHO) were factors associated with the diagnosis of PH.

CONCLUSION

This is the first study using an administrative database that provides real-world data on patients with PH in CLD in Japan. Our results indicate that PH may be misdiagnosed or underdiagnosed in Japan which may lead to suboptimal treatment for patients, and supports the need for further evidence to guide appropriate treatment.

Outcomes of patients with elevated pulmonary artery systolic pressure on echocardiography due to chronic lung diseases

BACKGROUND

Pulmonary hypertension is associated with increased mortality, and lung diseases are the second most common cause of pulmonary hypertension. We aimed to evaluate the prognostic value of echocardiography in low-middle income countries where right heart catheterization is difficult to perform.

METHODS

This retrospective chart review study included adult patients hospitalized from June 2012 to May 2021, with a pulmonary artery systolic pressure (PASP) of ≥35 mmHg on echocardiography. The control arm consisted of patients with similar lung diseases who did not have an elevated PASP.

RESULTS

The study and control arm consisted of 128 patients each, with both groups having similar lung diseases. Obesity hypoventilation syndrome was the most common etiology of elevated PASP (28.1 %), followed by pulmonary embolism (20.3 %). The overall 1-year mortality of the study cohort, after diagnosis of elevated PASP, was 20.3 %. The control cohort with normal PASP had a 1-year mortality of 4.7 %. In the study cohort, patients with bronchiectasis had the highest cause-specific 1-year mortality (45.5 %). In the normal PASP cohort, the highest cause-specific 1-year mortality was observed in patients with interstitial lung disease (13.0 %). One-year hospital readmission was observed in 46.9 % and 33.6 % of patients in the study and control arms, respectively. On multivariate analysis, increased odds of 1-year mortality were observed in patients with elevated PASP, patients with 1-year hospital readmission, and in patients with interstitial lung disease or bronchiectasis.

CONCLUSION

Elevated PASP on echocardiography may be a prognostic factor for mortality in patients with chronic lung diseases.

A Clinical Decision Tool for Risk Stratifying Patients with Systemic Sclerosis-Related Pulmonary Hypertension

We devised a scoring system to identify patients with systemic sclerosis (SSc) at risk for pulmonary hypertension (PH) and predict all-cause mortality. Using 7 variables obtained via pulmonary function testing, echocardiography, and computed tomographic chest imaging, we applied the score to a retrospective cohort of 117 patients with SSc. There were 60 (51.3%) who were diagnosed with PH by right heart catheterization. Using a scoring threshold ≥ 0, our decision tool predicted PH with a sensitivity, specificity, and accuracy of 0.87 (95% CI 0.75, 0.94), 0.74 (95% CI 0.60, 0.84), and 0.80 (95% CI 0.72, 0.87), respectively. When adjusted for age at PH diagnosis, sex, and receipt of pulmonary arterial vasodilators, each one-point score increase was associated with an adjusted HR of 1.19 (95% CI 1.05, 1.34) for all-cause mortality. With further validation in external cohorts, our simplified clinical decision tool may better streamline earlier detection of PH in SSc.

Accuracy of Transthoracic Echocardiogram as a Screening Method in the Clinical Practice of Pulmonary Hypertension Investigation

BACKGROUND

The transthoracic echocardiogram (TTE) plays a screening role in the diagnostic algorithm of pulmonary hypertension (PH). Studies have shown a significant disagreement between TTE measurements of the systolic pulmonary artery pressure (sPAP) and right atrial pressure (RAP) and those obtained by right heart catheterization (RHC).

OBJECTIVE

To compare TTE measurements of sPAP and RAP with those obtained by RHC in patients being investigated for PH.

METHODS

Patients referred to a PH reference center with a high or intermediate TTE probability of PH upon admission were submitted to RHC. The agreement between sPAP and RAP from both procedures was assessed through the Bland-Altman test. Differences of up to 10 mmHg for sPAP and 5 mmHg for RAP were considered within the variability of the test. Receiver Operating Characteristic (ROC) curve was constructed to determine the most accurate sPAP and Tricuspid regurgitation maximal velocity (TRV)values associated with the diagnosis of PH by RHC. The adopted level of statistical significance was 5%.

RESULTS

Ninety-five patients were included. The Bland-Altman analysis showed a bias of 8.03 mmHg (95% CI:-34.9-50.9) for sPAP and -3.30 mmHg (95% CI:-15.9-9.3) for RAP. AUC for sPAP and TRV measured by TTE for discrimination of probable PH were 0.936 (95% CI: 0.836-1.0) and 0.919 (95% CI: 0.837-1.0), respectively. However, only 33.4% of the echocardiographic estimate of sPAP and 55.1% of RAP were accurate, as compared to the measurements obtained by RHC.

CONCLUSION

TTE has a high discriminatory power as a screening diagnostic method for PH despite presenting disagreements between sPAP and RAP absolute values when compared to RHC measurements.

Diagnostic and prognostic value of echocardiography in pulmonary hypertension: an umbrella review of systematic reviews and meta-analyses

BACKGROUND

The role of echocardiography in the diagnostic and prognostic assessment of pulmonary hypertension (PH) has been widely studied recently. However, these findings have not undergone normative evaluation and may provide confusing evidence for clinicians. To evaluate and summarize existing evidence, we performed an umbrella review.

METHODS

Systematic reviews and meta-analyses were searched in PubMed, Embase, Web of Science, and Cochrane Library from inception to September 4, 2022. The methodological quality of the included studies was assessed using Assessment of Multiple Systematic Reviews (AMSTAR), and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the quality of evidence.

RESULTS

Thirteen meta-analyses (nine diagnostic and four prognostic studies) were included after searching four databases. The methodological quality of the included studies was rated as high (62%) or moderate (38%) by AMSTAR. The thirteen included meta-analyses involved a total of 28 outcome measures. The quality of evidence for these outcomes were high (7%), moderate (29%), low (39%), and very low (25%) using GRADE methodology. In the detection of PH, the sensitivity of systolic pulmonary arterial pressure is 0.85-0.88, and the sensitivity and specificity of right ventricular outflow tract acceleration time are 0.84. Pericardial effusion, right atrial area, and tricuspid annulus systolic displacement provide prognostic value in patients with pulmonary arterial hypertension with hazard ratios between 1.45 and 1.70. Meanwhile, right ventricular longitudinal strain has independent prognostic value in patients with PH, with a hazard ratio of 2.96-3.67.

CONCLUSION

The umbrella review recommends echocardiography for PH detection and prognosis. Systolic pulmonary arterial pressure and right ventricular outflow tract acceleration time can be utilized for detection, while several factors including pericardial effusion, right atrial area, tricuspid annular systolic displacement, and right ventricular longitudinal strain have demonstrated prognostic significance.

TRIAL REGISTRATION

PROSPERO (CRD42022356091), https://www.crd.york.ac.uk/prospero/ .

Aetiological distribution of pulmonary hypertension and the value of transthoracic echocardiography screening in the respiratory department: A retrospective analysis from China

METHODS

The aetiological composition and clinical characteristics of patients with pulmonary hypertension (PH) hospitalised in the respiratory department were retrospectively analysed, as well as the correlation between transthoracic echocardiography (TTE) and right heart catheterization (RHC) for evaluating pulmonary artery systolic pressure (PASP) and mean pulmonary artery pressure (mPAP).

RESULTS

Of 731 patients, 544 (74.42%) were diagnosed with PH by RHC. Pulmonary arterial hypertension (PAH) was the most common type of PH, accounting for 30.10%; PH due to lung disease and/or hypoxia accounted for 20.79%, and PH due to pulmonary artery obstructions accounted for 19.29%. TTE has the highest specificity for diagnosing PH due to pulmonary artery obstructions. The specificity was 0.9375, the sensitivity was 0.7361 and the area under the ROC curve (AUC) was 0.836. PASP, and mPAP estimated by TTE were different for various types of PH. In terms of PASP, TTE overestimated PASP in PH due to lung disease and/or hypoxia, but there was no significant difference compared with RHC (P > 0.05). TTE underestimates PAH patients' PASP compared with RHC. In terms of mPAP, TTE underestimated the mPAP of all types of PH, as there was a significant difference in the TTE-estimated mPAP of patients with PAH compared with RHC but not on other types of PH. Pearson correlation analysis of TTE and RHC showed a moderate overall correlation (rPASP 0.598, P < 0.001; rmPAP 0.588, P < 0.001).

CONCLUSIONS

Among the patients with PH in the respiratory department, patients with PAH accounted for the majority. TTE has high sensitivity and specificity for the diagnosis of PH due to pulmonary artery obstructions in the respiratory department.

Portopulmonary Hypertension

PoPH is a well-recognized complication of portal hypertension with or without cirrhosis and is classified as a subset of PAH. Identification of PoPH is crucial as it has a major impact on prognosis and liver transplant candidacy. Echocardiogram is the initial screening tool of choice and the patient should proceed to RHC for confirmation. PAH-directed therapy is the treatment of choice, allowing the patient to achieve a hemodynamic threshold to undergo a liver transplant safely.

The prevalence of pulmonary hypertension after successful tuberculosis treatment in a community sample of adult patients

There are an estimated 155 million survivors of tuberculosis (TB). Clinical experience suggests that post tuberculosis lung disease (PTLD) is an important cause of Group 3 pulmonary hypertension (PH). However, TB is not listed as a cause of PH in most guidelines. A cross-sectional, community-based study was conducted in nonhealthcare seeking adults who had successfully completed TB treatment. Subjects underwent questionnaires, spirometry, a 6-min walk distance test (6MWD) and transthoracic echocardiography (TTE). Screen probable PH was defined on TTE as an estimated pulmonary artery peak systolic pressure (PASP) of ≥40 mmHg. One hundred adults (71 males) were enrolled, with a mean age of 42 years (SD 13.8 years) and a median of one TB episode (interquartile range: 1-2). Co-morbidities included hypertension (21%), diabetes (16%), human immunodeficiency virus (10%) and asthma/COPD (5%). Only 25% had no residual symptoms after TB. Probable PH was found in 9%, while 7% had borderline raised PASP values (PASP 35-40 mmHg). An association was found between PH and the number of previous TB episodes, with each additional episode of TB increasing the odds of PH-postTB 2.13-fold (confidence interval [CI]: 1.17-3.88; p = 0.013). All of those found to have PH were smokers or ex-smokers yielding an unadjusted odds ratio for PH-postTB of 3.67 (95% CI: 0.77-17.46). There was no statistical difference in spirometry or 6MWD, between those with and without PH. Neither symptoms nor co-morbidities demonstrated significant association with PH. PH after TB was a common finding in this community-based population. Further research is needed to confirm and determine the significance of these findings.

Hemoglobin and End-Organ Damage in Individuals with Sickle Cell Disease

Background

Sickle cell disease (SCD) is an inherited, chronic, multifaceted blood disorder. Patients with SCD develop anemia, which has been associated with end-organ damage (EOD).

Objectives

This retrospective, observational, repeated-measures study systematically characterizes the relationship between hemoglobin (Hb) level and EOD in adolescent and adult patients with SCD.

Methods

The study population comprised patients with SCD aged ≥12 years with available Hb data from a US provider-centric health care database. For each patient, each Hb value over time was included as a separate observation. Study outcomes-the onset of any new EOD, including chronic kidney disease, pulmonary hypertension, stroke, and leg ulcer-were ascertained during the 1-year period after each Hb assessment. The association between Hb levels and risk of new EOD was estimated using multivariable generalized estimating equations.

Results

A total of 16,043 unique patients with SCD contributed 44,913 observations. Adjusted odds of any EOD during the 1-year follow-up were significantly lower with higher Hb level. Risk reductions with higher Hb levels for chronic kidney disease, pulmonary hypertension, and leg ulcer were comparable. The risk of new EOD was significantly lower among adolescent and adult patients with higher Hb levels.

Conclusions

In patients with SCD, higher Hb levels are associated with a reduced risk of developing EOD. Therapeutic strategies that result in higher Hb levels may offer clinical and economic value for patients with SCD. (Curr Ther Res Clin Exp. 2023; 84:XXX-XXX).

Construction of a diagnostic signature and immune landscape of pulmonary arterial hypertension

Background

Molecular biomarkers are widely used for disease diagnosis and exploration of pathogenesis. Pulmonary arterial hypertension (PAH) is a rapidly progressive cardiopulmonary disease with delayed diagnosis. Studies were limited regarding molecular biomarkers correlated with PAH from a broad perspective.

Methods

Two independent microarray cohorts comprising 73 PAH samples and 36 normal samples were enrolled in this study. The weighted gene co-expression network analysis (WGCNA) was performed to identify the key modules associated with PAH. The LASSO algorithm was employed to fit a diagnostic model. The latent biology mechanisms and immune landscape were further revealed via bioinformatics tools.

Results

The WGCNA approach ultimately identified two key modules significantly associated with PAH. For genes within the two models, differential expression analysis between PAH and normal samples further determined nine key genes. With the expression profiles of these nine genes, we initially developed a PAH diagnostic signature (PDS) consisting of LRRN4, PI15, BICC1, PDE1A, TSHZ2, HMCN1, COL14A1, CCDC80, and ABCB1 in GSE117261 and then validated this signature in GSE113439. The ROC analysis demonstrated outstanding AUCs with 0.948 and 0.945 in two cohorts, respectively. Besides, patients with high PDS scores enriched plenty of Th17 cells and neutrophils, while patients with low PDS scores were dramatically related to mast cells and B cells.

Conclusion

Our study established a robust and promising signature PDS for diagnosing PAH, with key genes, novel pathways, and immune landscape offering new perspectives for exploring the molecular mechanisms and potential therapeutic targets of PAH.

Correlation between Pulmonary Artery Pressure and Vortex Duration Determined by 4D Flow MRI in Main Pulmonary Artery in Patients with Suspicion of Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

Chronic thromboembolic pulmonary hypertension (CTEPH) is one of the causes of pulmonary hypertension (PH) and requires invasive measurement of the mean pulmonary artery pressure (mPAP) during right heart catheterisation (RHC) for the diagnosis. 4D flow MRI could provide non-invasive parameters to estimate the mPAP. Twenty-five patients with suspected CTEPH underwent cardiac MRI. Mean vortex duration (%), pulmonary distensibility, right ventricular volumes and function were measured using 4D flow MRI and cine sequences, and compared with the mPAP measured by RHC. The mPAP measured during RHC was 33 ± 16 mmHg (10−66 mmHg). PH (defined as mPAP > 20 mmHg) was present in 19 of 25 patients (76%). A vortical flow was observed in all but two patients (92%) on 4D flow images, and vortex duration showed good correlation with the mPAP (r = 0.805; p < 0.0001). Youden index analysis showed that a vortex duration of 8.6% of the cardiac cycle provided a 95% sensitivity and an 83% specificity to detect PH. Reliability for the measurement of vortex duration was excellent for both intra-observer ICC = 0.823 and inter-observer ICC = 0.788. Vortex duration could be a useful parameter to non-invasively estimate mPAP in patients with suspected CTEPH.

Blood flow analysis with computational fluid dynamics and 4D-flow MRI for vascular diseases

Both computational fluid dynamics (CFD) and time-resolved, three-dimensional, phase-contrast, magnetic resonance imaging (4D-flow MRI) enable visualization of time-varying blood flow structures and quantification of blood flow in vascular diseases. However, they are totally different. CFD is a method to calculate blood flow by solving the governing equations of fluid mechanics, so the obtained flow field is somewhat virtual. On the other hand, 4D-flow MRI measures blood flow in vivo, thus the flow is real. Recently, with the development and enhancement of computers, medical imaging techniques, and related software, blood flow analysis has become more accessible to clinicians and its usefulness in vascular diseases has been demonstrated. In this review, we have outlined the methods and characteristics of CFD and 4D-flow MRI, respectively. We have discussed the differences in the characteristics between both methods; reviewed the milestones achieved by blood flow analysis in various vascular diseases; and discussed the usefulness, challenges, and limitations of blood flow analysis. We have discussed the difficulties and limitations of current blood flow analysis. We have also discussed our views on future directions.

Clinical outcomes of bileaflet St. Jude Medical and tilting disc TTK Chitra mechanical heart valve prosthesis: A comparative study

BACKGROUND

Comparative data on the clinical outcomes of TTK Chitra mechanical heart valve prosthesis (CHVP), an indigenously developed low-cost tilting disc valve and commonly used bileaflet valve, the St. Jude medical (SJM) prosthesis are sparse.

METHODS

We conducted a retrospective follow-up study of consecutive patients undergoing mitral (MVR) and aortic valve replacement (AVR) with SJM or CHVP mechanical prostheses over a 6-year period at our institution.

RESULTS

Seven hundred and thirty-five patients who underwent isolated MVR (n = 510) or AVR (n = 225) were included in the study. Patients with CHVP were younger and belonged to a lower socioeconomic class. The study cohort was followed-up for 2836 patient-years (SJM: 1865.1, CHVP: 971.0). All-cause mortality (p = 0.894), valve-related mortality (p = 0.681), prosthetic valve thrombosis (p = 0.155), embolism (p = 0.210), hemorrhage (p = 0.959) and infective endocarditis (IE, p = 0.084) were similar between both valve on follow-up. Estimated event free survival was 2302 ± 1 days in SJM as compared to 2484 ± 65 days in CHVP group (p = 0.393). Valve type was not an independent predictor of adverse events after adjusting for baseline data, time in therapeutic range and aspirin use. Subgroup analysis of patients who underwent MVR and AVR showed similar functional improvement and outcomes, except for a higher incidence of IE with SJM at the aortic position (p = 0.041).

CONCLUSION

The indigenously developed, low-cost CHVP has comparable midterm clinical performance as SJM in aortic or mitral positions.

Doppler trans-thoracic echocardiography for detection of pulmonary hypertension in adults

BACKGROUND

Pulmonary hypertension (PH) is an important cause of morbidity and mortality, which leads to a substantial loss of exercise capacity. PH ultimately leads to right ventricular overload and subsequent heart failure and early death. Although early detection and treatment of PH are recommended, due to the limited responsiveness to therapy at late disease stages, many patients are diagnosed at a later stage of the disease because symptoms and signs of PH are nonspecific at earlier stages. While direct pressure measurement with right-heart catheterisation is the clinical reference standard for PH, it is not routinely used due to its invasiveness and complications. Trans-thoracic Doppler echocardiography is less invasive, less expensive, and widely available compared to right-heart catheterisation; it is therefore recommended that echocardiography be used as an initial diagnosis method in guidelines. However, several studies have questioned the accuracy of noninvasively measured pulmonary artery pressure. There is substantial uncertainty about the diagnostic accuracy of echocardiography for the diagnosis of PH.

OBJECTIVES

To determine the diagnostic accuracy of trans-thoracic Doppler echocardiography for detecting PH.

SEARCH METHODS

We searched MEDLINE, Embase, Web of Science Core Collection, ClinicalTrials.gov, World Health Organization International Clinical Trials Registry Platform from database inception to August 2021, reference lists of articles, and contacted study authors. We applied no restrictions on language or type of publication.

SELECTION CRITERIA

We included studies that evaluated the diagnostic accuracy of trans-thoracic Doppler echocardiography for detecting PH, where right-heart catheterisation was the reference standard. We excluded diagnostic case-control studies (two-gate design), studies where right-heart catheterisation was not the reference standard, and those in which the reference standard threshold differed from 25 mmHg. We also excluded studies that did not provide sufficient diagnostic test accuracy data (true-positive [TP], false-positive [FP], true-negative [TN], and false-negative [FN] values, based on the reference standard). We included studies that provided data from which we could extract TP, FP, TN, and FN values, based on the reference standard. Two authors independently screened and assessed the eligibility based on the titles and abstracts of records identified by the search. After the title and abstract screening, the full-text reports of all potentially eligible studies were obtained, and two authors independently assessed the eligibility of the full-text reports.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias and extracted data from each of the included studies. We contacted the authors of the included studies to obtain missing data. We assessed the methodological quality of studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. We estimated a summary receiver operating characteristic (SROC) curve by fitting a hierarchical summary ROC (HSROC) non-linear mixed model. We explored sources of heterogeneity regarding types of PH, methods to estimate the right atrial pressure, and threshold of index test to diagnose PH. All analyses were performed using the Review Manager 5, SAS and STATA statistical software.

MAIN RESULTS

We included 17 studies (comprising 3656 adult patients) assessing the diagnostic accuracy of Doppler trans-thoracic echocardiography for the diagnosis of PH. The included studies were heterogeneous in terms of patient distribution of age, sex, WHO classification, setting, country, positivity threshold, and year of publication. The prevalence of PH reported in the included studies varied widely (from 6% to 88%). The threshold of index test for PH diagnosis varied widely (from 30 mmHg to 47 mmHg) and was not always prespecified. No study was assigned low risk of bias or low concern in each QUADAS-2 domain assessed. Poor reporting, especially in the index test and reference standard domains, hampered conclusive judgement about the risk of bias. There was little consistency in the thresholds used in the included studies; therefore, common thresholds contained very sparse data, which prevented us from calculating summary points of accuracy estimates. With a fixed specificity of 86% (the median specificity), the estimated sensitivity derived from the median value of specificity using HSROC model was 87% (95% confidence interval [CI]: 78% to 96%). Using a prevalence of PH of 68%, which was the median among the included studies conducted mainly in tertiary hospitals, diagnosing a cohort of 1000 adult patients under suspicion of PH would result in 88 patients being undiagnosed with PH (false negatives) and 275 patients would avoid unnecessary referral for a right-heart catheterisation (true negatives). In addition, 592 of 1000 patients would receive an appropriate and timely referral for a right-heart catheterisation (true positives), while 45 patients would be wrongly considered to have PH (false positives). Conversely, when we assumed low prevalence of PH (10%), as in the case of preoperative examinations for liver transplantation, the number of false negatives and false positives would be 13 and 126, respectively.

AUTHORS' CONCLUSIONS

Our evidence assessment of echocardiography for the diagnosis of PH in adult patients revealed several limitations. We were unable to determine the average sensitivity and specificity at any particular index test threshold and to explain the observed variability in results. The high heterogeneity of the collected data and the poor methodological quality would constrain the implementation of this result into clinical practice. Further studies relative to the accuracy of Doppler trans-thoracic echocardiography for the diagnosis of PH in adults, that apply a rigorous methodology for conducting diagnostic test accuracy studies, are needed.

Right Ventricular Response to Acute Hypoxia Exposure: A Systematic Review

Background: Acute hypoxia exposure is associated with an elevation of pulmonary artery pressure (PAP), resulting in an increased hemodynamic load on the right ventricle (RV). In addition, hypoxia may exert direct effects on the RV. However, the RV responses to such challenges are not fully characterized. The aim of this systematic review was to describe the effects of acute hypoxia on the RV in healthy lowland adults.

Methods: We systematically reviewed PubMed and Web of Science and article references from 2005 until May 2021 for prospective studies evaluating echocardiographic RV function and morphology in healthy lowland adults at sea level and upon exposure to simulated altitude or high-altitude.

Results: We included 37 studies in this systematic review, 12 of which used simulated altitude and 25 were conducted in high-altitude field conditions. Eligible studies reported at least one of the RV variables, which were all based on transthoracic echocardiography assessing RV systolic and diastolic function and RV morphology. The design of these studies significantly differed in terms of mode of ascent to high-altitude, altitude level, duration of high-altitude stay, and timing of measurements. In the majority of the studies, echocardiographic examinations were performed within the first 10 days of high-altitude induction. Studies also differed widely by selectively reporting only a part of multiple RV parameters. Despite consistent increase in PAP documented in all studies, reports on the changes of RV function and morphology greatly differed between studies.

Conclusion: This systematic review revealed that the study reports on the effects of acute hypoxia on the RV are controversial and inconclusive. This may be the result of significantly different study designs, non-compliance with international guidelines on RV function assessment and limited statistical power due to small sample sizes. Moreover, the potential impact of other factors such as gender, age, ethnicity, physical activity, mode of ascent and environmental factors such as temperature and humidity on RV responses to hypoxia remained unexplored. Thus, this comprehensive overview will promote reproducible research with improved study designs and methods for the future large-scale prospective studies, which eventually may provide important insights into the RV response to acute hypoxia exposure.

Prognostic value of main pulmonary artery diameter to ascending aorta diameter ratio in patients with advanced heart failure

OBJECTIVES AND BACKGROUND

In this study we assessed the prognostic value of main pulmonary artery diameter and its ratio to ascending aorta diameter (P/Ao ratio) in advanced heart failure patients.

METHODS

Patients with advanced heart failure who were candidates for heart transplantation were retrospectively evaluated. The clinical information, cardiac catheterisation results, and computed tomography images were gathered from institutional database system. The observed and predicted probabilities for survival were analysed in a nomogram.

RESULTS

The P/Ao ratio was found to be a strong predictor for MACE both in traditional multivariable Cox proportional hazard regression modelling (increase in P/Ao ratio per 2 SD, HR:2.72, 95% CI 1.14-6.48, p = 0.024) and ridge regression analysis (increase in P/Ao ratio per 2SD, HR:3.45, 95% CI 1.53-7.74, p = 0.003). Prediction model showed statistically significant correlation between the observed and predicted probabilities for 1-year survival.

CONCLUSION

In patients with advanced heart failure, computed tomography derived P/Ao ratio might be a prognostic predictor during follow up.

Using a non-invasive multi-sensor device to evaluate left atrial pressure: an estimated filling pressure derived from ballistocardiography

BACKGROUND

Heart failure is a global health problem, and elevated left atrial pressure (LAP) is a precursor to identifying decompensated heart failure. At present, out-of-hospital monitoring of patients with heart failure is mostly based on the patient's symptoms and signs, and the use of non-invasive technology is scarce. In this study, a non-invasive ballistocardiography (BCG) device was used to collect thoracic vibration signals generated by heartbeat. We collected these signals from more than 1,000 adults, including those with different heart diseases, and used a sensor system and a composite index related to LAP recognition named the LAP-index, to analyze them. This study aimed to verify the reliability and accuracy of the LAP-index in identifying elevated LAP within heart failure patients.

METHODS

We prospectively included 158 patients with various extent of diastolic function, some of whom had various underlying diseases, and collected BCG and echocardiographic data using a cross-section methodology. The BCG signal was recorded from multiple optical fiber vibration sensors placed on the back of each patient. We adopted the 2016 ASE/EACVI echocardiography guideline as the standard for determining LAP level from echocardiography parameters. To evaluate the diagnostic efficacy of the LAP-index, we drew a receiver operating characteristic (ROC) curve and calculated the area under the ROC curve (AUC).

RESULTS

The LAP-index of the 158 patients ranged from 6 to 32. Of them, 39 were diagnosed as high LAP by echocardiography, and 119 cases had normal or slightly elevated LAP. Comparison of the LAP-index results and echocardiographic results revealed the ROC c-statistic of the LAP-index for identifying high LAP was 0.86 (95% CI: 0.79-0.93; P<0.0001). When the LAP-index was at the best cut-off value of 15.5, the positive agreement rate between it and echocardiography LAP was 0.85, the negative agreement rate was 0.80, and the overall agreement rate was 0.81.

CONCLUSIONS

The sensor system and the LAP-index, a composite index derived from BCG, have high reliability and accuracy in identifying elevated LAP, which provides a novel possibility for the non-invasive detection of hemodynamic congestion in heart failure patients.

Unenhanced computed tomography as a diagnostic tool in suspected pulmonary hypertension: a retrospective cross-sectional pilot study

Background: Computed tomography pulmonary angiography (CTPA) has been proposed to be diagnostic for pulmonary hypertension (PH) in multiple studies. However, the utility of the unenhanced CT measurements diagnosing PH has not been fully assessed.  This study aimed to assess the diagnostic utility and reproducibility of cardiac and great vessel parameters on unenhanced computed tomography (CT) in suspected pulmonary hypertension (PH). Methods: In total, 42 patients with suspected PH who underwent unenhanced CT thorax and right heart catheterization (RHC) were included in the study. Three observers (a consultant radiologist, a specialist registrar in radiology, and a medical student) measured the parameters by using unenhanced CT. Diagnostic accuracy of the parameters was assessed by area under the receiver operating characteristic curve (AUC). Inter-observer variability between the consultant radiologist (primary observer) and the two secondary observers was determined by intra-class correlation analysis (ICC). Results: Overall, 35 patients were diagnosed with PH by RHC while 7 patients were not. Main pulmonary arterial (MPA) diameter was the strongest (AUC 0.79 to 0.87) and the most reproducible great vessel parameter. ICC comparing the MPA diameter measurement of the consultant radiologist to the specialist registrar’s and the medical student’s were 0.96 and 0.92, respectively. Right atrial area was the cardiac measurement with highest accuracy and reproducibility (AUC 0.76 to 0.79; ICC 0.980, 0.950) followed by tricuspid annulus diameter (AUC 0.76 to 0.79; ICC 0.790, 0.800). Conclusions: MPA diameter and right atrial areas showed high reproducibility. Diagnostic accuracies of these were within the range of acceptable to excellent, and might have clinical value. Tricuspid annular diameter was less reliable and less diagnostic and was therefore not a recommended diagnostic measurement.

Estimation of pulmonary artery pressure with transesophageal echocardiography: An observer-blinded test accuracy study

With the declining use of the pulmonary artery catheter (PAC), transesophageal echocardiography (TEE) has become an appealing alternative to obtain pulmonary artery pressure non-invasively using the simplified Bernoulli equation. The validation of this method in the perioperative setting has been scarce with no clear recommendations about which view is the most accurate to estimate right ventricular systolic pressure (RVSP).Therefore, we performed a prospective, observer-blinded, diagnostic test accuracy study to assess the difference in systolic pulmonary artery pressure (sysPAP) measuring both, invasively sysPAP and estimated RVSP with TEE in 3 different views: the mid-esophageal (ME) 4Chamber, the ME right ventricular (RV) inflow-outflow and the ME modified bicaval view.To show a clinically significant difference of at least 10% in RVSP, we included 40 cardiac surgical patients divided into 3 subgroups: Patients with mild to moderate tricuspid regurgitation (TR) and mean PAP <25 mm Hg, patients with mild to moderate TR and mean PAP≥ 25 mm Hg, and patients with severe TR.For the whole cohort, bias of estimated RVSP compared to measured sysPAP was 5.27 mm Hg, precision was 7.96 mm Hg, limits of agreement were -10.66 to 21.19 mm Hg. The best agreement between the 2 methods was found in patients with severe TR and in the ME RV inflow-outflow and the modified bicaval view. Good Doppler signals were available in 35% and 46% in these views, and in 20% in the ME 4 chamber view.The estimation of the sysPAP by TEE cannot be considered reliable in the clinical perioperative setting. Only measurements that provide a full Doppler envelope show sufficient precision to provide accurate estimations.

Optimal Tricuspid Regurgitation Velocity to Screen for Pulmonary Hypertension in Tertiary Referral Centers

BACKGROUND

A mean pulmonary artery pressure >20 mmHg now defines pulmonary hypertension. We hypothesize that echocardiographic thresholds need to be adjusted.

RESEARCH QUESTION

Should TRV thresholds to screen for PH be revised given the new hemodynamic definition?

STUDY DESIGN AND METHODS

This multicenter retrospective study included 1,608 patients that underwent both echocardiography and right heart catherization within four weeks. The discovery cohort consisted of 1,081 individuals and the validation cohort included 527. Screening criteria for pulmonary hypertension were derived using receiver operating characteristic analysis and the Youden index assuming equal cost for false positive and negative classification. A lower threshold was calculated using a predefined sensitivity: 95%.

RESULTS

In the discovery cohort, echocardiographic tricuspid regurgitation velocity had a good discrimination for pulmonary hypertension, AUC 88.4 (95% CI, 85.3-91.5). A 3.4 m/s threshold provided a 78% sensitivity, 87% specificity, and 6.13 positive likelihood ratio to detect pulmonary hypertension. 2.7 m/s had a 95% sensitivity and 0.12 negative likelihood ratio to exclude pulmonary hypertension. In the validation cohort, the discovery threshold of 2.7 m/s provided a sensitivity and negative likelihood ratio of 80% and 0.34, respectively. Right cardiac size improved detection of pulmonary hypertension in the lower tricuspid regurgitation velocity groups.

INTERPRETATION

Our data support a lower tricuspid regurgitation velocity around 2.7 m/s for screening pulmonary hypertension with a high sensitivity in tertiary referral centers. Right heart chamber measurements improve the diagnostic yield of echocardiography.

Outcomes and Risk Factors of Systolic Pulmonary Artery Pressure Progression in Patients with Systemic Rheumatic Diseases: Follow-up Results from a Korean Registry

Objectives

This study aims to investigate the outcomes and risk factors associated with the progression of systolic pulmonary artery pressure (sPAP) in patients with systemic rheumatic diseases.

Patients and methods

A total of 532 patients (73 males, 459 females; median age 49 years; interquartile range (IQR), 36 to 62 years) registered with the Registry of Pulmonary Hypertension Associated with Rheumatic Diseases were included. Mortality curves were constructed using the Kaplan- Meier method and comparisons were performed using the log-rank test. A paired t-test was performed to evaluate the patients with markedly elevated sPAP between baseline and follow-up.

Results

The average follow-up duration was 31 months (IQR, 9 to 60 months). Of the patients, 196 had follow-up echocardiographs at least one year later. We defined the sPAP over 60 mmHg as markedly elevated. Patients in the increased sPAP above 60 mmHg at follow-up and persistently markedly elevated sPAP were associated with worse outcomes in all-cause mortality and pulmonary arterial hypertension-related mortality (p<0.001). In patients with systemic sclerosis, the majority of patients remained static within their pressure group or rose progressively: the patients with markedly elevated sPAP at follow-up were higher than those at baseline (32% versus 15%, p<0.01). In patients with mixed connective tissue disease (MCTD) or rheumatoid arthritis (RA), the majority of patients remained static within their pressure group or gradually improved: the patients with markedly elevated sPAP at follow-up were lower than those at baseline (RA=14% versus 29%, MCTD=5% versus 16%, p<0.05).

Conclusion

Persistently high sPAP or increase of sPAP over 60 mmHg at follow-up was associated with increased mortality. There were some differences in the progression of sPAP according to the underlying rheumatic diseases.

Diagnostic value of chest spiral CT scan and Doppler echocardiography compared to right heart catheterization to predict pulmonary arterial hypertension in patients with scleroderma

BACKGROUND

Because of invasive nature of catheterization, using other noninvasive tools is more preferred to assess pulmonary arterial hypertension (PAH). The present study assessed the value of chest spiral CT scan and Doppler echocardiography compared to right heart catheterization (RHC) to predict PAH in patients with scleroderma.

METHODS

This cross-sectional study was performed on 15 patients with limited scleroderma. All subjects underwent Doppler echocardiography (to assess PAP) and chest spiral CT scan without injection (to assess pulmonary trunk length or PUL), followed by RHC to assess PAH.

RESULTS

Comparing PUL in spiral CT scan with PAP in RHC yielded a sensitivity of 75.0% and a specificity of 100% for predicting PAH. Similarly, comparing PAP value in echocardiography with PAP in RHC achieved a sensitivity of 100% and a specificity of 63.6% to discriminate PAH from normal PAP condition. Analysis of the area under the ROC curve showed high power of CT scan to predict PAH (AUC = 1.000). The best cutoff point for PUL to predict PAH was 29.95 yielding a sensitivity of 100% and a specificity of 100%. Also, ROC curve analysis showed high value of echocardiography to discriminate PAH from normal PAP status (AUC = 0.841) that considering a cutoff value of 22.88 for PAP assessed by echocardiography reached to a sensitivity of 72.7% and a specificity of 100%.   Conclusion: Both chest spiral CT scan and Doppler echocardiography are very useful to diagnose PAH and its severity in patients with scleroderma.

A machine learning cardiac magnetic resonance approach to extract disease features and automate pulmonary arterial hypertension diagnosis

AIMS

Pulmonary arterial hypertension (PAH) is a progressive condition with high mortality. Quantitative cardiovascular magnetic resonance (CMR) imaging metrics in PAH target individual cardiac structures and have diagnostic and prognostic utility but are challenging to acquire. The primary aim of this study was to develop and test a tensor-based machine learning approach to holistically identify diagnostic features in PAH using CMR, and secondarily, visualize and interpret key discriminative features associated with PAH.

METHODS AND RESULTS

Consecutive treatment naive patients with PAH or no evidence of pulmonary hypertension (PH), undergoing CMR and right heart catheterization within 48 h, were identified from the ASPIRE registry. A tensor-based machine learning approach, multilinear subspace learning, was developed and the diagnostic accuracy of this approach was compared with standard CMR measurements. Two hundred and twenty patients were identified: 150 with PAH and 70 with no PH. The diagnostic accuracy of the approach was high as assessed by area under the curve at receiver operating characteristic analysis (P < 0.001): 0.92 for PAH, slightly higher than standard CMR metrics. Moreover, establishing the diagnosis using the approach was less time-consuming, being achieved within 10 s. Learnt features were visualized in feature maps with correspondence to cardiac phases, confirming known and also identifying potentially new diagnostic features in PAH.

CONCLUSION

A tensor-based machine learning approach has been developed and applied to CMR. High diagnostic accuracy has been shown for PAH diagnosis and new learnt features were visualized with diagnostic potential.

Comparative analysis on the anti-inflammatory/immune effect of mesenchymal stem cell therapy for the treatment of pulmonary arterial hypertension

Despite the advancement of targeted therapy for pulmonary arterial hypertension (PAH), poor prognosis remains a reality. Mesenchymal stem cells (MSCs) are one of the most clinically feasible alternative treatment options. We compared the treatment effects of adipose tissue (AD)-, bone marrow (BD)-, and umbilical cord blood (UCB)-derived MSCs in the rat monocrotaline-induced pulmonary hypertension (PH) model. The greatest improvement in the right ventricular function was observed in the UCB-MSCs treated group. The UCB-MSCs treated group also exhibited the greatest improvement in terms of the largest decrease in the medial wall thickness, perivascular fibrosis, and vascular cell proliferation, as well as the lowest levels of recruitment of innate and adaptive immune cells and associated inflammatory cytokines. Gene expression profiling of lung tissue confirmed that the UCB-MSCs treated group had the most notably attenuated immune and inflammatory profiles. Network analysis further revealed that the UCB-MSCs group had the greatest therapeutic effect in terms of the normalization of all three classical PAH pathways. The intravenous injection of the UCB-MSCs, compared with those of other MSCs, showed superior therapeutic effects in the PH model for the (1) right ventricular function, (2) vascular remodeling, (3) immune/inflammatory profiles, and (4) classical PAH pathways.

Advanced Imaging in Pulmonary Vascular Disease

Although the diagnosis of pulmonary hypertension requires invasive testing, imaging serves an important role in the screening, classification, and monitoring of patients with pulmonary vascular disease (PVD). The development of advanced imaging techniques has led to improvements in the understanding of disease pathophysiology, noninvasive assessment of hemodynamics, and stratification of patient risk. This article discusses the current role of advanced imaging and the emerging novel techniques for visualizing the lung parenchyma, mediastinum, and heart in PVD.

Cardiac Acclimatization at High Altitude in Two Different Ethnicity Groups

Gaur, Priya, Meerim Sartmyrzaeva, Abdirashit Maripov, Kubatbek Muratali Uulu, Supriya Saini, Koushik Ray, Krishna Kishore, Almaz Akunov, Akpay Sarybaev, Bhuvnesh Kumar, Shashi Bala Singh, and Praveen Vats. Cardiac acclimatization at high altitude in two different ethnicity groups. High Alt Med Biol. 22:58-69, 2021. Introduction: High altitude (HA) exposure causes substantial increase in pulmonary artery pressure (PAP) and resistance. However, the effects of HA hypoxia exposure on cardiac function remain incompletely understood. Studies evaluating interethnic differences in cardiac functions in response to HA exposure are lacking. We aimed to compare the cardiac performance in Indian versus Kyrgyz healthy lowland subjects over the course of a 3-week HA exposure at 4,111 m. Methodology: Ten Indians and 20 Kyrgyz subjects were studied to assess cardiac acclimatization noninvasively by echocardiography in two different ethnic groups for 3 weeks of stay at HA. Pulmonary hemodynamics, right and left ventricular functions were evaluated at basal and on days 3, 7, 14, and 21 of HA exposure and on day 3 of deinduction. Results: HA exposure significantly increased PAP, pulmonary vascular resistance, cardiac output (CO), and heart rates (HRs) in both groups. Tricuspid regurgitant gradient increased significantly in both the group at day 3 versus basal; 38.9 mmHg (31.8, 42.9) versus 21.9 mmHg (19.5, 22.6) in Kyrgyz; and 34.1 mmHg (30.2, 38.5) versus 20.4 mmHg (19.7, 21.3) in Indians. HR increased significantly in Indians at day 3 and 7, whereas in Kyrgyz throughout exposure. CO increased significantly in both groups at day 3 versus basal with 5.9 L/min (5.5, 6.4) versus 5.1 L/min (4.4, 5.9) in Kyrgyz, and 5.7 L/min (5.56, 5.98) versus 4.9 L/min (4.1, 5.3) in Indians. Both groups exhibited preserved right ventricular diastolic and systolic functions at HAs. HA exposure changed the left ventricular diastolic parameters only in Kyrgyz subjects with impaired mitral inflow E/A, but not in Indian subjects. All cardiac changes induced at HAs have been recovered fully upon deinduction in both, except lateral-septal A', which remained low in Indians. Conclusion: Although pulmonary hemodynamics responses were similar in both groups, there were differences in cardiac functional parameters between the two in response to HA exposure that may be accounted to ethnic variation.

The potential effect of cardiac function on pulmonary hypertension, other risk factors, and its impact on survival in dialysis patients

INTRODUCTION

Pulmonary hypertension (PH) is a recently recognized as a complication of chronic kidney disease and end-stage renal disease. The pathogenesis of pulmonary hypertension in this group of patients is not fully understood, probably due to the interaction of multiple aspects of the altered cardiovascular physiology and also hormonal and metabolic disorders. The present study aimed to determine the prevalence of PH, correlation with cardiac function and other risk factors and its impact of survival in chronic hemodialysis and peritoneal dialysis patients.

METHODS

We studied 125 stable hemodialysis and peritoneal patients (females 40%, mean age 52.42 ± 11.88 years) on renal replacement therapy (RRT) for more than 3 months with a follow up 2 years. Demographic information, clinical characteristics, blood test, and thoroughly echocardiographic evaluation at the optimal dry weight were collected. After conventional echocardiographic examination, tissue Doppler echocardiographic (TDE) examination was performed to evaluate global and regional myocardial systolic as well as diastolic function, and pulmonary hypertension. PH was defined as systolic pulmonary artery pressure (sPAP) ≥ 35 mmHg. To rule out secondary PH, patients with pulmonary disease, collagen vascular disease, and volume overload at the time of echocardiography were excluded. Variables were compared between two groups-subjects with PH and non-PH. Logistic regression analysis was used to evaluate the risk factor for PH and its impact on survival.

RESULTS

According to the echocardiographic findings, PH was found in 28% (35 patients) of all patients. Mean PH was 33.46 ± 5.38 mmHg. The higher level of higher parathormone (PTH), C-reactive protein (CRP) and E/E' average, lower left ventricular ejection fraction (EF), peak systolic velocity at the lateral mitral annulus (MASa) and the peak systolic velocity at the lateral tricuspid annulus (TASa) were found predictor of PH. The cardiovascular mortality rate was 15.5%. Patients evaluated with PH have a significantly lower cardiovascular survival rate [Long Rank (Mantel-Cox) p = 0.0001]. In ROC analysis for CV mortality, the area under the curve (AUC) for PH and CRP was found 0.8; for LVM-I, E/E' and PP, AUC = 0.76; 0.75; 0.72 respectively while the inverse relationship was found with MASa and TASa with AUC = 0.66 and 0.95 respectively.

CONCLUSION

Our study shows that PH is frequent in dialysis patients. It is influenced by inflammation, CKD-MBD biomarkers associated with diastolic and also systolic left and right ventricle dysfunction. Pulmonary hypertension, inflammation, vascular stiffness, and left ventricular hypertrophy are interrelated and all contribute to cardiovascular morbidity and mortality among dialysis patients. Easy to implement, cardiac imaging at the bedside and in outpatient clinics offers a positive perspective in early diagnosis of cardiac abnormalities and immediate approach to this condition, so is highly recommended in the dialysis population.

Correlation Between Doppler Echocardiography and Right Heart Catheterisation-Derived Systolic and Mean Pulmonary Artery Pressures: Determinants of Discrepancies Between the Two Methods

BACKGROUND

There is still controversy about whether transthoracic echocardiography (TTE) can provide reliable estimations of pulmonary artery pressures (PAP). The primary endpoint of this study was to evaluate the correlation between TTE and right heart catheterisation (RHC) in estimating systolic (SPAP) and mean (MPAP) pulmonary artery pressures.

METHODS

Between January 2011 and December 2018, 141 consecutive patients (average age 63.6±11.5 years; 84 women) with suspected or confirmed pulmonary hypertension (PH) were enrolled into this retrospective observational monocentric study. All patients underwent TTE and, within 3 hours, RHC. The correlation between TTE and RHC in estimating both SPAP and MPAP was retrospectively determined.

RESULTS

Seventeen (17) of the patients were excluded due to insufficient TTE signal quality. Of the remaining 124 patients, 18 had no PH. There was moderate correlation between both SPAP and MPAP estimated by TTE and those assessed by RHC (r=0.65 and r=0.60, respectively). Bland-Altman analysis revealed a bias of -11.9 mmHg (with the 95% limits of agreement ranging -45.4 to +21.5 mmHg) for SPAP estimation and -4.6 mmHg (with the 95% limits of agreement ranging -27.9 to +18.8 mmHg) for MPAP estimation, suggesting a general overestimation of PAP by TTE. The main factors responsible for discrepancies between TTE and RHC were: female gender, arrhythmic cardiac electrical activity, systemic arterial hypertension, and diuretic treatment.

CONCLUSIONS

Transthoracic echocardiography frequently overestimated PAP in comparison with RHC, especially in hypertensive women with arrhythmias and under diuretic treatment.

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.

Role of echocardiography in screening for portopulmonary hypertension in liver transplant candidates: a meta-analysis

Objectives

To demonstrate the screening value of echocardiography for portopulmonary hypertension (POPH) in liver transplant candidates.

Design

Systematic review and meta-analysis.

Background

POPH is a complication of end-stage liver disease that adversely affects the outcome of orthotopic liver transplant. There are no specific symptoms in the early stage of POPH. POPH reduce the survival rate of patients with end-stage liver disease specially if they are not diagnosed. Therefore, early detection may improve prognosis. The objective of this study is to explore the screening value of echocardiography on liver transplant candidates for screening of POPH compared to right heart catheterization (RHC).

Method

PubMed, EMBASE and the Cochrane Library were searched by two independent reviewers for potentially eligible studies published up to 30 June 2019 to retrieve data based on per-patient analysis. STATA, Meta-DiSc, and RevMan were applied to perform this meta-analysis.

Results

Our search yielded 1576 studies, of which 11 satisfied the inclusion criteria. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the summary receiver operating characteristic (SROC) curve (AUC) of echocardiography for POPH were 0.85 (95% CI [0.65–0.94]), 0.83 (95% CI [0.73–0.90]), 4.99 (95% CI [3.03–8.21]), 0.19 (95% CI [0.07–0.46]), and 0.91 (95% CI [0.88–0.93]), respectively. Deeks’ funnel plot did not indicate the existence of publication bias (P = 0.66).

Conclusions

Echocardiography, a noninvasive modality, provides superior screening for POPH, but the diagnosis of POPH still requires RHC. PROSPERO registration number CRD42019144589.

Diagnostic accuracy of CT pulmonary angiography in suspected pulmonary hypertension

Objectives

Computed tomography (CT) pulmonary angiography is widely used in patients with suspected pulmonary hypertension (PH). However, the diagnostic and prognostic significance remains unclear. The aim of this study was to (a) build a diagnostic CT model and (b) test its prognostic significance.

Methods

Consecutive patients with suspected PH undergoing routine CT pulmonary angiography and right heart catheterisation (RHC) were identified. Axial and reconstructed images were used to derive CT metrics. Multivariate regression analysis was performed in the derivation cohort to identify a diagnostic CT model to predict mPAP ≥ 25 mmHg (the existing ESC guideline definition of PH) and > 20 mmHg (the new threshold proposed at the 6th World Symposium on PH). In the validation cohort, sensitivity, specificity and compromise CT thresholds were identified with receiver operating characteristic (ROC) analysis. The prognostic value of the CT model was assessed using Kaplan-Meier analysis.

Results

Between 2012 and 2016, 491 patients were identified. In the derivation cohort (n = 247), a CT model was identified including pulmonary artery diameter, right ventricular outflow tract thickness, septal angle and left ventricular area. In the validation cohort (n = 244), the model was diagnostic, with an area under the ROC curve of 0.94/0.91 for mPAP ≥ 25/> 20 mmHg respectively. In the validation cohort, 93 patients died; mean follow-up was 42 months. The diagnostic thresholds for the CT model were prognostic, log rank, all p < 0.01.

Discussion

In suspected PH, a diagnostic CT model had diagnostic and prognostic utility.

Key Points

• Diagnostic CT models have high diagnostic accuracy in a tertiary referral population of with suspected PH.

• Diagnostic CT models stratify patients by mortality in suspected PH.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-06846-1) contains supplementary material, which is available to authorized users.

The changing face of pulmonary hypertension diagnosis: a historical perspective on the influence of diagnostics and biomarkers

Pulmonary hypertension is a complex, multifactorial disease that results in right heart failure and premature death. Since the initial reports of pulmonary hypertension in the late 1800s, the diagnosis of pulmonary hypertension has evolved with respect to its definition, screening tools, and diagnostic techniques. This historical perspective traces the earliest roots of pulmonary hypertension detection and diagnosis through to the current recommendations for classification. We highlight the diagnostic tools used in the past and present, and end with a focus on the future directions of early detection. Early detection of pulmonary hypertension and pulmonary arterial hypertension and the proper determination of etiology are vital for the early therapeutic intervention that can prolong life expectancy and improve quality of life. The search for a non-invasive screening tool for the identification and classification of pulmonary hypertension is ongoing, and we discuss the role of animal models of the disease in this search.

Cardiac Catheterization versus Echocardiography for Monitoring Pulmonary Pressure: A Prospective Study in Patients with Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

Standard echocardiography is important for pulmonary arterial hypertension (PAH) screening in patients with connective tissue disease (CTD), but PAH diagnosis and monitoring require cardiac catheterization. Herein, using cardiac catheterization as reference, we tested the hypothesis that follow-up echocardiography is adequate for clinical decision-making in these patients. We prospectively studied 69 consecutive patients with CTD-associated PAH. Invasive baseline pulmonary artery systolic pressure (PASP) was 60.19 ± 16.33 mmHg (mean ± SD) and pulmonary vascular resistance (PVR) was 6.44 ± 2.95WU. All patients underwent hemodynamic and echocardiographic follow-up after 9.47 ± 7.29 months; 27 patients had a third follow-up after 17.2 ± 7.4 months from baseline. We examined whether clinically meaningful hemodynamic deterioration of follow-up catheterization-derived PASP (i.e., > 10% increase) could be predicted by simultaneous echocardiography. Echocardiography predicted hemodynamic PASP deterioration with 59% sensitivity, 85% specificity, and 63/83% positive/negative predictive value, respectively. In multivariate analysis, successful echocardiographic prediction correlated only with higher PVR in previous catheterization (p = 0.05, OR = 1.235). Notably, in patients having baseline PVR > 5.45 WU, echocardiography had both sensitivity and positive predictive values of 73%, and both specificity and negative predictive value of 91% for detecting hemodynamic PASP deterioration. In selected patients with CTD-PAH echocardiography can predict PASP deterioration with high specificity and negative predictive value. Additional prospective studies are needed to confirm that better patient selection can increase the ability of standard echocardiography to replace repeat catheterization.

Diagnostic accuracy of transthoracic echocardiography for pulmonary hypertension: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic accuracy of transthoracic echocardiography (TTE) in patients with pulmonary hypertension (PH).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES AND ELIGIBILITY CRITERIA

Embase, Cochrane Library for clinical trials, PubMed and Web of Science were used to search studies from inception to 19 June, 2019. Studies using both TTE and right heart catheterisation (RHC) to diagnose PH were included.

MAIN RESULTS

A total of 27 studies involving 4386 subjects were considered as eligible for analysis. TTE had a pooled sensitivity of 85%, a pooled specificity of 74%, a pooled positive likelihood ratio of 3.2, a pooled negative likelihood ratio of 0.20, a pooled diagnostic OR of 16 and finally an area under the summary receiver operating characteristic curve of 0.88. The subgroup with the shortest time interval between TTE and RHC had the best diagnostic effect, with sensitivity, specificity and area under the curve (AUC) of 88%, 90% and 0.94, respectively. TTE had lower sensitivity (81%), specificity (61%) and AUC (0.73) in the subgroup of patients with definite lung diseases. Subgroup analysis also showed that different thresholds of TTE resulted in a different diagnostic performance in the diagnosis of PH.

CONCLUSION

TTE has a clinical value in diagnosing PH, although it cannot yet replace RHC considered as the gold standard. The accuracy of TTE may be improved by shortening the time interval between TTE and RHC and by developing an appropriate threshold. TTE may not be suitable to assess pulmonary arterial pressure in patients with pulmonary diseases.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019123289.

Prognostic impact of the ratio of the main pulmonary artery to that of the aorta on chest computed tomography in patients with idiopathic pulmonary fibrosis

Background

In many clinical disorders, there is a relationship between the ratio of the diameter of the main pulmonary artery (mPA) to that of the aorta (Ao) on chest computed tomography (CT). The aim of this study was to determine if the mPA/Ao ratio at diagnosis is associated with the clinical characteristics and outcomes in patients with idiopathic pulmonary fibrosis (IPF).

Methods

We retrospectively reviewed the diameters of the pulmonary artery and aorta on chest CT, clinical characteristics, and results of other examinations in 303 patients at the time of initial diagnosis of IPF at our tertiary care center between 2011 and 2015. The primary outcomes were death and lung transplantation. The patients were followed up until June 2017.

Results

One hundred and eight patients (35.6%) died and 58 (19.1%) underwent lung transplantation during follow-up. The mean mPA and Ao diameters were 28.3 mm and 34.0 mm, respectively, and the mean mPA/Ao ratio was 0.84. Thirty-one patients (10.2%) had an mPA/Ao ratio > 1.0 and 182 (60.1%) had an mPA/Ao ratio > 0.8. Patients with an mPA/Ao ratio > 0.8 had a lower DLco value than those with an mPA/Ao ratio ≤ 0.8. In Kaplan-Meier analysis, patients with an mPA/Ao ratio > 1.0 or > 0.8 had worse outcomes than those with an mPA/Ao ratio ≤ 1.0 and ≤ 0.8, respectively.

Conclusions

A higher mPA/Ao ratio based on 1.0 and 0.8 is associated with unfavorable prognosis in patients with IPF.

Utility of transesophageal echocardiography for intra-operatively assessing pulmonary artery pressure across an isolated ventricular septal defect in children

BACKGROUND

The magnitude of pulmonary hypertension (PH) is extremely important with respect to the intra-operative management of children and infants with an isolated ventricular septal defect (VSD). This study aimed to assess the feasibility and accuracy of transesophageal echocardiography for estimating pulmonary arterial systolic pressure (PASP) across isolated VSD.

METHODS

We compared the results of transesophageal echocardiography vs invasive PASP measured simultaneously. This study included 40 patients (age: 6 months to 6 years; weight: >5 kg) who were undergoing elective surgery for isolated VSDs. Flow signals across the VSDs were identified as high velocity turbulent signals in systole via continuous wave Doppler at 0-120° at the mid-esophageal level. Peak velocities were recorded. Radial artery systolic pressures were assessed invasively, and PASPs were obtained after exposing the pulmonary artery intra-operatively.

RESULTS

After excluding five patients because of unusable measurements, invasive PASP measurements were obtained in 35 patients (87.5%). There were no significant biases between echocardiographic and catheterization measurements of PASP, with a tight confidence interval measuring, on average, up to 2.6 mmHg. However, the ± 2 standard deviation limits of agreement for mean PASP were -3.8 and 10.6 mmHg.

CONCLUSION

PASP measurements via transesophageal echocardiography in cardiac surgical patients under general anesthesia are recommended for use as a screening and monitoring tool for PH in children and infants, but cannot be used as a diagnostic tool.

High mobility group box 1 protein (HMGB1) as biomarker in hypoxia-induced persistent pulmonary hypertension of the newborn: a clinical and in vivo pilot study

Background: Inflammation plays an important role in neonatal hypoxia-induced organ damage. Newborns with perinatal asphyxia often develop persistent pulmonary hypertension of the newborn (PPHN). The objective of this study was to explore changes in the pro-inflammatory high mobility group box-l (HMGB1) protein during hypoxia-induced PPHN clinically and in vivo. Methods: Serum samples were collected from full-term newborns at PPHN onset and remission. As controls, blood serum samples were collected from the umbilical arteries of healthy full-term newborns born in our hospital during the same period. Clinical data for neonates were collected and serum levels of HMGB1, IL-6, and TNF-α were detected by enzyme-linked immunosorbent assay (ELISA). An animal study compared a PPHN Sprague-Dawley rat model to healthy newborn control rats. Histopathology was used to evaluate changes in the pulmonary artery wall. ELISA and western blot analyses were used to examine HMGB1 levels in the serum and lungs. Results: Serum HMGB1 levels were significantly elevated in newborns with PPHN, compared to those in healthy controls, and decreased dramatically after PPHN resolution. HMGB1 changes were positively correlated with serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels. Histopathological analysis demonstrated that the median wall thickness of pulmonary arterioles accounting for the percentage of pulmonary arteriole diameter (MT%) was not significantly different between PPHN and control groups 3 d after PPHN, although thickness of the small pulmonary arterial wall middle membrane and stenosis of the small pulmonary arteries. ELISA and western blot analyses showed similar trends between serum HMGB1 levels and HMGB1 protein expression in the lungs. Serum and lung HMGB1 levels were significantly elevated soon after PPHN onset, peaked after 24 h, and then decreased after 3 d, although they remained elevated compared to those in the control group. Conclusions: This study indicates that HMGB1 is related to hypoxia-induced PPHN pathogenesis. HMGB1 changes might thus be used as an early indicator to diagnose hypoxia-induced PPHN and evaluate its improvement. We also provide important evidence for the involvement of inflammation in the progression of hypoxia-induced PPHN.

Validating Left Ventricular Filling Pressure Measurements in Patients with Congestive Heart Failure: CardioMEMS™ Pulmonary Arterial Diastolic Pressure versus Left Atrial Pressure Measurement by Transthoracic Echocardiography

Background

Routine ambulatory echocardiographic estimates of left ventricular (LV) filling pressures are not cost-effective and are occasionally fraught with anatomic, physiologic as well as logistical limitations. The use of implantable hemodynamic devices such as CardioMEMS Heart Failure (HF) System has been shown to reduce HF-related readmission rates by remote monitoring of LV filling pressures. Little is known about the correlation between CardioMEMS and echocardiography-derived estimates of central hemodynamics.

Methods

We performed a prospective, single-center study enrolling seventeen participants with New York Heart Association functional class II-III HF and preimplanted CardioMEMS sensor. Simultaneous CardioMEMS readings and a limited echocardiogram were performed at individual clinic visits. Estimated left atrial pressure (LAP) by echocardiogram was calculated by the Nagueh formula. Linear regression was used as a measure of agreement. Variability between methods was evaluated by Bland–Altman analysis.

Results

Mean age was 74 ± 9 years; 59% (10/17) were males. LV systolic dysfunction was present in 76% (13/17) of subjects. Mean PAdP was 18 ± 4 mmHg and 19 ± 5 mmHg for CardioMEMS and echocardiographic-derived estimates, respectively, with a significant correlation between both methods (r²=0.798, p ≤ 0.001).

Conclusions

Our study illustrates a direct linear correlation between PAdP measured by CardioMEMS and simultaneous measurement of LV filling pressures derived by echocardiography.

The role of diagnostic cardiac catheterization for children with congenital heart diseases: local experience

Introduction

Despite the development of non-invasive tools of investigations for congenital heart diseases (CHDs), still the role of diagnostic cardiac catheterization (DCC) cannot be undermined. The study aimed to analyze the clinical profile of indicated CHDs cases at our center for DCC to evaluate the contribution of DCC in patients’ management plans.

Material and methods

The study checked files of cases performed DCC between 2011 and 2012 at the pediatric catheterization unit of Alexandria University Children’s Hospital by the same operator. Demographic, laboratory and hemodynamic data were collected and analyzed.

Results

Files of 61 children were included in the study. They were grouped into: group I (GI) (n = 25) with pulmonary hypertension (PH), and group II (GII) (n = 36) cases with obstructive pulmonary artery diseases. For the PH group, ventricular septal defect (VSD) was the most common (55%), and patients’ outcome plans were based on angiography – operable subgroup GI-A: (84%) (n = 21) and non-operable (16%) GI-B: (4% inoperable, 12% recommended for sildenafil). GI-B cases were significantly older, with higher PVRI and PVRI/SVRI (3.62, 0.68, p = 0.002) compared to GI-A (0.89, 0.23, p = 0.002, respectively). For group II, tetralogy of Fallot (TOF) was predominant (60%) among the disease spectrum, and the McGoon ratio ranged from 0.7 to 3.2 (median: 1.8). Outcome for GII: 63% operable, 25% shunt, 12% stent. Only pulmonary atresia cases showed a significant difference in the unmatched plans between echocardiography and catheterization reports (χ² = 7.438, p = 0.023).

Conclusions

Diagnostic cardiac catheterization had a positive contribution for determination of the management plans for more than 84% of cases. The utility of pediatric cardiac catheterization in diagnosis should be adjusted according to the local needs of every cardiac center.

ACR Appropriateness Criteria® Suspected Pulmonary Hypertension

Pulmonary hypertension may be idiopathic or related to a large variety of diseases. Various imaging examinations that may be helpful in diagnosing and determining the etiology of pulmonary hypertension are discussed. Imaging examinations that may aid in the diagnosis of pulmonary hypertension include chest radiography, ultrasound echocardiography, ventilation/perfusion scans, CT, MRI, right heart catheterization, pulmonary angiography, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Long-Term Intermittent Work at High Altitude: Right Heart Functional and Morphological Status and Associated Cardiometabolic Factors

Background: Living at high altitude or with chronic hypoxia implies functional and morphological changes in the right ventricle and pulmonary vasculature with a 10% prevalence of high-altitude pulmonary hypertension (HAPH). The implications of working intermittently (day shifts) at high altitude (hypobaric hypoxia) over the long term are still not well-defined. The aim of this study was to evaluate the right cardiac circuit status along with potentially contributory metabolic variables and distinctive responses after long exposure to the latter condition. Methods: A cross-sectional study of 120 healthy miners working at an altitude of 4,400-4,800 m for over 5 years in 7-day commuting shifts was designed. Echocardiography was performed on day 2 at sea level. Additionally, biomedical and biochemical variables, Lake Louise scores (LLSs), sleep disturbances and physiological variables were measured at altitude and at sea level. Results: The population was 41.8 ± 0.7 years old, with an average of 14 ± 0.5 (range 5-29) years spent at altitude. Most subjects still suffered from mild to moderate symptoms of acute mountain sickness (mild was an LLS of 3-5 points, including cephalea; moderate was LLS of 6-10 points) (38.3%) at the end of day 1 of the shift. Echocardiography showed a 23% mean pulmonary artery pressure (mPAP) >25 mmHg, 9% HAPH (≥30 mmHg), 85% mild increase in right ventricle wall thickness (≥5 mm), 64% mild right ventricle dilation, low pulmonary vascular resistance (PVR) and fairly good ventricle performance. Asymmetric dimethylarginine (ADMA) (OR 8.84 (1.18-66.39); p < 0.05) and insulin (OR: 1.11 (1.02-1.20); p < 0.05) were associated with elevated mPAP and were defined as a cut-off. Interestingly, the correspondence analysis identified association patterns of several other variables (metabolic, labor, and biomedical) with higher mPAP. Conclusions: Working intermittently at high altitude involves a distinctive pattern. The most relevant and novel characteristics are a greater prevalence of elevated mPAP and HAPH than previously reported at chronic intermittent hypobaric hypoxia (CIHH), which is accompanied by subsequent morphological characteristics. These findings are associated with cardiometabolic factors (insulin and ADMA). However, the functional repercussions seem to be minor or negligible. This research contributes to our understanding and surveillance of this unique model of chronic intermittent high-altitude exposure.

Cardiovascular parameters of chest CT scan in estimating pulmonary arterial pressure in patients with pulmonary hypertension

OBJECTIVE

To develop a formula to compute mean pulmonary arterial pressure (MPAP) by chest computerized tomography (CT), and to verify its accuracy and reliability.

METHODS

Eighty-five patients who had taken chest CT and right heart catheterization (RHC) were recruited. The pulmonary arterial systolic pressure (PASP), pulmonary arterial diastolic pressure (PADP), and MPAP of each subject were measured and recorded by RHC. The diameters of the ascending aorta (dAA), descending aorta (dDA) and main pulmonary artery (dMPA), Cobb angle, diameters of right ventricle (dRV), diameters of left ventricle (dLV) were measured by means of chest CT scans. Systolic blood pressure (SBP) was measured by using electronic sphygmomanometer. A linear regression equation was generated in 56 patients to estimate PAP based on chest CT values, 29 patients were used to test the accuracy of the formula.

RESULTS

The computed equation for analyzing MPAP is: MPAP = 9.011 + 34.195 × dMPA/dAA - 0.319 × SBP + 0.402 × Cobb angle. AUC of equation with three variables (dMPA/dAA, SBP, and Cobb angle) was 0.923 with 95% CI (0.863-0.982). The mean ± SD of predicted values and RHC values had no statistical difference.

CONCLUSIONS

Ratio of dMAP/dAA, Cobb angle, and SBP can be reliably used to estimate MPAP and predict severity of PH.

Team-based approach to identify cardiac toxicity in critically ill hematopoietic stem cell transplant recipients

INTRODUCTION

We observed pulmonary hypertension (PH), pericardial effusions, and left ventricular systolic dysfunction (LVSD) in multiple critically ill hematopoietic stem cell transplant (HSCT) recipients. We implemented routine structured echocardiography screening for HSCT recipients admitted to the pediatric intensive care unit (PICU) using a standardized multidisciplinary process.

METHODS

HSCT recipients admitted to the PICU with respiratory distress, hypoxia, shock, and complications related to transplant-associated thrombotic microangiopathy were screened on admission and every 1-2 weeks thereafter. Echocardiography findings requiring intervention and/or further screening included elevated right ventricular pressure, LVSD, and moderate to large pericardial effusions. All echocardiograms were compared to the patient's routine pretransplant echocardiogram.

RESULTS

Seventy HSCT recipients required echocardiography screening over a 3-year period. Echo abnormalities requiring intervention and/or further screening were found in 35 (50%) patients. Twenty-four (34%) patients were noted to have elevated right ventricular pressure; 14 (20%) were at risk for PH, while 10 (14%) had PH. All patients with PH were treated with pulmonary vasodilators. LVSD was noted in 22 (31%) patients; 15/22 (68%) received inotropic support. Moderate to large pericardial effusions were present in nine (13%) patients, with six needing pericardial drain placement.

DISCUSSION

Echocardiographic abnormalities are common in critically ill HSCT recipients. Utilization of echocardiogram screening may allow for early detection and timely intervention for cardiac complications in this high-risk cohort.