Echocardiography in pulmonary arterial hypertension: from diagnosis to prognosis

Right ventricular systolic to diastolic duration ratio: A novel predictor of outcome in adult idiopathic pulmonary arterial hypertension

BACKGROUND

The systolic to diastolic (SD) duration ratio reflects global RV performance in pulmonary arterial hypertension (PAH) yet limited data exists on its application to adult non-congenital PAH. We measured SD ratios on echocardiogram in idiopathic PAH (IPAH) to establish its response to pulmonary vasodilator therapy and prognostic value at diagnosis and follow up.

METHODS

Incident patients with IPAH undergoing echocardiogram, haemodynamic and exercise assessments were identified within our centre between 2005 and 2018. SD ratios were adjusted for heart rate at diagnosis and follow up.

RESULTS

In 98 patients at diagnosis, the mean SD ratio was 1.03 ± 0.37 decreasing to 0.85 ± 0.25, p < 0.001 at follow-up echocardiogram performed at a median interval of 9.0 months. The SD ratio at diagnosis correlated weakly with RV basal diameter (r = 0.24, p = 0.04) and 6MWD (r = 0.23, p = 0.04). At follow up, the mean SD ratio was lower in those receiving combination vs monotherapy pulmonary vasodilator treatment (71 ± 25 vs 92 ± 22% baseline respectively, p < 0.001). After a median follow-up of 4.8 years, 3 patients were transplanted and 23 patients died. The SD ratio at diagnosis and follow up predicted an increased risk of death/transplantation (HR 2.41 (1.09-5.29), p = 0.03; HR 5.02 (1.27-19.77), p = 0.02 respectively), retaining its predictive value at diagnosis in bivariate models with 6MWD (HR 2.18 (1.06-4.08)), WHO Functional Class (HR 2.33 (1.04-5.21)) and TAPSE (HR 2.36 (1.07-5.19)), all p < 0.05.

CONCLUSIONS

The SD ratio carries prognostic value at diagnosis and follow up in IPAH. Its further evaluation alongside current PAH risk stratification parameters should be considered.

Pulmonary hypertension subjects exhibit right ventricular transient exertional dilation during supine exercise stress echocardiography

Pulmonary hypertension is a condition with high morbidity and mortality. Resting transthoracic echocardiography is a pivotal diagnostic and screening test for pulmonary hypertension. The role of exercise stress echocardiography in the diagnosis of pulmonary hypertension is not well-established. We studied right ventricular size changes during exercise using exercise stress echocardiography to assess differences between normal and pulmonary hypertension patients and evaluate test safety, feasibility, and reproducibility. Healthy control and pulmonary hypertension patients performed recumbent exercise using a bicycle ergometer. Experienced echocardiography sonographers recorded the following resting and peak exercise right ventricular parameters using the apical four chamber view: end-diastolic area; end-systolic area; mid-diameter; basal diameter; and longitudinal diameter. Two cardiologists masked to clinical information subsequently analyzed the recordings. Parameters with acceptable inter-rater reliability were analyzed for statistical differences between the normal and pulmonary hypertension patient groups and their association with pulmonary hypertension. We enrolled 38 healthy controls and 40 pulmonary hypertension patients. Exercise stress echocardiography testing was found to be safe and feasible. Right ventricular size parameters were all readily obtainable and all had acceptable inter-observer reliability except for right ventricular longitudinal diameter. During exercise, healthy controls demonstrated a decrease in right ventricular end-systolic area, end-diastolic area, mid-diameter, and basal diameter ( P < 0.05). Conversely, pulmonary hypertension patients demonstrated an increase in right ventricular end-systolic area, end-diastolic area, and mid-diameter ( P < 0.05). These changes were unaffected by multivariate corrections. The sensitivity for pulmonary hypertension of an increase in right ventricular size was 97.2% with a negative predictive value of 95.2%. The ROC C-statistic for increase in right ventricular size was 0.93. This transient exertional dilation (TED) of the right ventricle is observed in pulmonary hypertension patients but not in healthy controls. Recumbent right ventricular exercise stress echocardiography is a feasible and safe diagnostic test for pulmonary hypertension which warrants additional study.

Distinct plasma gradients of microRNA-204 in the pulmonary circulation of patients suffering from WHO Groups I and II pulmonary hypertension

Pulmonary hypertension (PH), a heterogeneous vascular disease, consists of subtypes with overlapping clinical phenotypes. MicroRNAs, small non-coding RNAs that negatively regulate gene expression, have emerged as regulators of PH pathogenesis. The muscle-specific micro RNA (miR)-204 is known to be depleted in diseased pulmonary artery smooth muscle cells (PASMCs), furthering proliferation and promoting PH. Alterations of circulating plasma miR-204 across the trans-pulmonary vascular bed might provide mechanistic insights into the observed intracellular depletion and may help distinguish PH subtypes. MiR-204 levels were quantified at sequential pulmonary vasculature sites in 91 patients with World Health Organization (WHO) Group I pulmonary arterial hypertension (PAH) (n = 47), Group II PH (n = 22), or no PH (n = 22). Blood from the right atrium/superior vena cava, pulmonary artery, and pulmonary capillary wedge was collected. Peripheral blood mononuclear cells (PBMCs) were isolated (n = 5/group). Excretion of miR-204 by PAH-PASMCs was also quantified in vitro. In Group I patients only, miR-204 concentration increased sequentially along the pulmonary vasculature (log fold-change slope = 0.22 [95% CI = 0.06–0.37], P = 0.008). PBMCs revealed insignificant miR-204 variations among PH groups (P = 0.12). Cultured PAH-PAMSCs displayed a decrease of intracellular miR-204 (P = 0.0004), and a converse increase of extracellular miR-204 (P = 0.0018) versus control. The stepwise elevation of circulating miR-204 across the pulmonary vasculature in Group I, but not Group II, PH indicates differences in muscle-specific pathobiology between subtypes. Considering the known importance of miR-204 in PH, these findings may suggest pathologic excretion of miR-204 in Group I PAH by PASMCs, thereby accounting for decreased intracellular miR-204 concentration.

Frequency and predictors of pulmonary hypertension in patients with Systemic Lupus Erythematosus

Objective:

To determine the frequency and predictors of pulmonary hypertension in patients with Systemic Lupus Erythematosus in a Pakistani population, presenting at a tertiary care hospital

Methods:

This cross-sectional study was conducted at the Department of Rheumatology, Shiekh Zayed Hospital, Lahore from March to June 2018. A total of 97 patients, who fulfilled the Systemic Lupus Erythematosus (SLE) criteria of American College of Rheumatology (ACR) 1992 were enrolled. Pulmonary Arterial Hypertension (PAH) was measured by calculating pulmonary arterial systolic pressure through echocardiography by a single consultant cardiologist. Disease characteristics and demography was collected in a self-administered proforma. PAH was defined as mean pulmonary arterial pressure of 25mmHg or above by calculating with a formula. SPSS version 20 was used for analysis of data.

Results:

Out of 97 patients, 89.7% (n=87) were females and 10.3% (n=10) were males, with mean age of 31.29± 8.824 years. The mean disease duration was 24.21 ± 30.46 months. PAH was found in 23.3% (n=23) patients, including 19 females and 4 males. On further analysis of data, Raynaud phenomenon, rheumatoid factor and nephritis were assessed as predictors of PAH and all of these showed statistical significance for presence of PAH as per Chi-square test (p<0.05).

Conclusion:

In this study, 23.3% SLE patients showed evidence of PAH and positive statistical significance was found between predictors like Raynaud phenomenon, rheumatoid factor, nephritis and presence of PAH. So it is imperative to detect PAH early and start prompt treatment to achieve better quality of life.

EXPRESS: Statement on imaging and pulmonary hypertension from the Pulmonary Vascular Research Institute (PVRI)

Pulmonary hypertension (PH) is highly heterogeneous and despite treatment advances it remains a life-shortening condition. There have been significant advances in imaging technologies, but despite evidence of their potential clinical utility, practice remains variable, dependent in part on imaging availability and expertise. This statement summarizes current and emerging imaging modalities and their potential role in the diagnosis and assessment of suspected PH. It also includes a review of commonly encountered clinical and radiological scenarios, and imaging and modeling-based biomarkers. An expert panel was formed including clinicians, radiologists, imaging scientists, and computational modelers. Section editors generated a series of summary statements based on a review of the literature and professional experience and, following consensus review, a diagnostic algorithm and 55 statements were agreed. The diagnostic algorithm and summary statements emphasize the key role and added value of imaging in the diagnosis and assessment of PH and highlight areas requiring further research.

Non-invasive Multimodality Cardiovascular Imaging of the Right Heart and Pulmonary Circulation in Pulmonary Hypertension

Pulmonary hypertension (PH) is defined as resting mean pulmonary arterial pressure (mPAP) ≥25 millimeters of mercury (mmHg) via right heart (RH) catheterization (RHC), where increased afterload in the pulmonary arterial vasculature leads to alterations in RH structure and function. Mortality rates have remained high despite therapy, however non-invasive imaging holds the potential to expedite diagnosis and lead to earlier initiation of treatment, with the hope of improving prognosis. While historically the right ventricle (RV) had been considered a passive chamber with minimal role in the overall function of the heart, in recent years in the evaluation of PH and RH failure the anatomical and functional assessment of the RV has received increased attention regarding its performance and its relationship to other structures in the RH-pulmonary circulation. Today, the RV is the key determinant of patient survival. This review provides an overview and summary of non-invasive imaging methods to assess RV structure, function, flow, and tissue characterization in the setting of imaging's contribution to the diagnostic, severity stratification, prognostic risk, response of treatment management, and disease surveillance implications of PH's impact on RH dysfunction and clinical RH failure.

EXPRESS: Sildenafil for bronchopulmonary dysplasia and pulmonary hypertension: a meta-analysis

Bronchopulmonary dysplasia (BPD) is the most common complication in preterm infants and often complicated by pulmonary hypertension (PH), leading to substantial morbidity and mortality. Sildenafil is often used to treat PH and improve symptoms in this condition, even though evidence of safety and effectiveness is scarce. The aim of this study was to perform a systematic review and meta-analysis about the effectiveness and safety of chronic use of sildenafil in preterm infants with BPD-associated PH. Data sources were PubMed, EMBASE, and Medline. Studies reporting the effectiveness of sildenafil therapy in BPD-associated PH in newborns and infants were included. All-cause mortality, improvement in PH, improvement in respiratory scores, and adverse events were extracted. Five studies were included, yielding a total of 101 patients with 94.2 patient-years of total follow-up. The pooled mortality rate was 29.7%/year (95% confidence interval [CI] = 6.8–52.7). Estimated pulmonary arterial pressure improved > 20% in 69.3% (95% CI = 56.8–81.8) of patients within 1–6 months. Respiratory scores improved in 15.0% (95% CI = 0.0–30.4) of patients within 2–7 days. There were no serious adverse events during sildenafil therapy. This systematic review shows that in the treatment of BPD-associated PH in preterm infants, sildenafil may be associated with improvement in PAP and respiratory scores. However, there is no clear evidence of its effect on mortality rates. Considering BPD as a complex disease with variable expression patterns, these results support the need for a prospective registry and standardized approach.

Genetic Strain and Sex Differences in a Hyperoxia-Induced Mouse Model of Varying Severity of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is a disease prevalent in preterm babies with a need for supplemental oxygen, resulting in impaired lung development and dysregulated vascularization. Epidemiologic studies have shown that males are more prone to BPD and have a delayed recovery compared with females, for reasons unknown. Herein, we tried to recapitulate mild, moderate, and severe BPD, using two different strains of mice, in males and females: CD1 (outbred) and C57BL/6 (inbred). Aside from higher body weight in the CD1 strain, there were no other gross morphologic differences with respect to alveolar development between the two strains. With respect to lung morphology after oxygen exposure, females had less injury with better preservation of alveolar chord length and decreased alveolar protein leak and inflammatory cells in the bronchoalveolar lavage fluid. In addition, housekeeping genes, which are routinely used as loading controls, were expressed differently in males and females. In the BPD mouse model, gonadotropin-releasing hormone was increased in females compared with males. Specific miRNAs (miR-146 and miR-34a) were expressed differently in the sexes. In the severe BPD mouse model, administering miR-146 mimic to males attenuated lung damage, whereas administering miR-146 inhibitor to females increased pulmonary injury.

Long-term outcome in patients with Takotsubo syndrome presenting with severely reduced left ventricular ejection fraction

AIM

To evaluate the long-term outcome of patients with Takotsubo syndrome (TTS) and severely reduced left ventricular ejection fraction (LVEF ≤ 35%) at presentation.

METHODS AND RESULTS

The study population included 326 patients (mean age 69.5 ± 10.7 years, 28 male) with TTS enrolled in the Takotsubo Italian Network, divided into two groups according to LVEF (≤ 35%, n = 131; > 35%, n = 195), as assessed by transthoracic echocardiography at hospital admission. In-hospital events were recorded in both groups. At long-term follow-up (median 26.5 months, interquartile range 18-33), composite major adverse cardiac events (MACE: cardiac death, acute myocardial infarction, heart failure, and TTS recurrence) and rehospitalization were investigated. Compared to patients with LVEF > 35%, patients with LVEF ≤ 35% were older (71.2 ± 10.8 vs. 68.4 ± 10.6 years; P = 0.026) and experienced more frequently cardiogenic shock (16% vs. 4.6%; P < 0.001), acute heart failure (28.2% vs. 12.8%; P = 0.001), and intra-aortic balloon pump support (11.5% vs. 2.6%; P = 0.001) in the acute phase. At long-term follow-up, higher rates of composite MACE (25.2% vs. 10.8%; P = 0.001) and rehospitalization for cardiac causes (26% vs. 13.3%; P = 0.004) were observed in these patients. LVEF ≤ 35% at admission [hazard ratio (HR) 2.184, 95% confidence interval (CI) 1.231-3.872; P = 0.008] and age (HR 1.041, 95% CI 1.011-1.073; P = 0.006) were independent predictors of MACE. Patients with LVEF ≤ 35% also had a significant lower freedom from composite MACE during long-term follow-up (χ² = 11.551, P = 0.001).

CONCLUSION

Left ventricular ejection fraction ≤ 35% at presentation is a key parameter to identify TTS patients at higher risk not only in the acute phase but also at long-term follow-up.

Agreement of an echocardiogram-based diagnosis of pulmonary hypertension in infants at risk for bronchopulmonary dysplasia among masked reviewers

OBJECTIVE

To evaluate the agreement of an echocardiogram-based pulmonary hypertension diagnosis in premature infants at risk for bronchopulmonary dysplasia (BPD).

STUDY DESIGN

Echocardiograms from infants born ≤28 weeks post menstrual age were retrospectively reviewed with a standardized reading protocol by three pediatric cardiologists masked to patient's clinical history to determine the presence of pulmonary hypertension.

RESULTS

A total of 483 echocardiograms from 49 unique patients were each reviewed by three pediatric cardiologists. Overall there was an 82.9% agreement on the presence of pulmonary hypertension among the three readers (95% CI: 78.4%, 85.4%) with a modified Fleiss' kappa of 0.759 (95% CI: 0.711, 0.801). Percent agreement between rereads was 92.4%, and modified Fleiss' kappa was 0.847 (95% CI: 0.750, 0.931).

CONCLUSIONS

Using a standardized reading protocol and echocardiogram-based definition of pulmonary hypertension, there is high inter- and intra-rater agreement for the diagnosis of pulmonary hypertension in at-risk premature infants, suggesting echocardiography can be successfully used for clinical and research monitoring of pulmonary hypertension in infants.

Normal values of the pulmonary artery acceleration time (PAAT) and the right ventricular ejection time (RVET) in children and adolescents and the impact of the PAAT/RVET-index in the assessment of pulmonary hypertension

New echocardiographic modalities including pulmonary artery acceleration time (PAAT) and right ventricular ejection time (RVET) are evolving to facilitate an early non-invasive diagnosis for pulmonary hypertension (PH) in adults. In children, PAAT depends on age, body surface area (BSA) and heart rate (HR) and is used to predict PH. Normal values of RVET and their role to predict PH in children are still missing. PAAT/RVET-index correlates negatively with PH. We hypothesized that this index is a good predictor for PH in children and adolescents independent of age, BSA and HR and RVET is significantly reduced in PH. PAAT and RVET of 401 healthy children and 30 PH-patients were measured using pulsed-wave-Doppler. PH was diagnosed in PH-group invasively. PAAT/RVET-index for both groups was calculated. Sensitivity and specificity in prediction of PH of PAAT, PAAT z-score and PAAT/RVET-index were compared. We demonstrated normal values of RVET in children. In the healthy group, PAAT and RVET correlated significant positive to age (p < 0.001), and BSA (p < 0.001) and negative to HR (p < 0.001). PAAT/RVET-index correlated weakly to age, BSA and HR (p < 0.001). Mean pulmonary artery pressure (PAPM) ranged in the PH-group from 27 to 82 mmHg (mean 44 mmHg). In predicting PH, RVET is significantly reduced (p < 0.001). Comparing area under the curve (AUC), the difference between sensitivity and specificity of PAAT/RVET-index < 0.29 and calculated PAAT cut-off-point (87 ms) was significant (p < 0.001). Equally, AUC comparison between PAAT/RVET-index < 0.29 and PAAT z-score of - 1.33 was significant (p = 0.008). PAAT/RVET-index < 0.29 represents a good predictor of PH with a 100% sensitivity and a 95.8% specificity. PAAT/RVET-index is a simple tool and facilitates prediction of PH independent from z-scores.

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

INTRODUCTION

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

Reliability of Doppler echocardiography in the assessment of high pulmonary vascular resistance in patients with severe pulmonary arterial hypertension

BACKGROUND

The objective is to assess whether the squaring of tricuspid regurgitation velocity (TRV) gives an improved estimate of pulmonary vascular resistance (PVR) or is equivalent to the ratio of TRV and time velocity integral of right ventricular outflow tract (TVI_RVOT) (TRV/TVI_RVOT) for assessing PVR in patients with high PVR values.

METHODS

Thirty patients predicted to have PVR >6 WU by Doppler were included in the present study. TRV and TVI_RVOT were measured by echo Doppler. TRV/TVI_RVOT and TRV²/TVI_RVOT were calculated. PVR_CATH was estimated within 2 h of Doppler study. Regression equations for calculating PVR from TRV/TVI_RVOT (PVR_ECHO1) and TRV²/TVI_RVOT (PVR_ECHO2) were developed. Bland-Altman analysis for agreement between PVR_CATH and PVR_ECHO1, PVR_ECHO2 was carried out.

RESULTS

The mean value of PVR_CATH was found to be 15.08 ± 7.03 WU. The calculated values of PVR_ECHO1 and PVR_ECHO2 were found to be 15.08 ± 6.34 WU and 15.05 ± 6.08 WU, respectively. The linear regression analysis carried out for PVR_CATH and TRV/TVI_RVOT showed good correlation (R = 0.84). Bland-Altman analysis showed excellent agreement between the two Doppler methods and invasive PVR with negligible bias.

CONCLUSION

Noninvasive estimation of PVR by Doppler is reliable even in patients with high PVR (>6 WU) and, squaring TRV is not superior to TRV alone.

Right ventricular size and function under riociguat in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (the RIVER study)

BACKGROUND

Riociguat is a soluble guanylate cyclase stimulator approved for pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTPEH). The objective of this study was to evaluate right heart size and function assessed by echocardiography during long term treatment with riociguat.

METHODS

Patients who started riociguat treatment (1.0-2.5 mg tid) within the trials phase II, PATENT, PATENTplus, EAS, CHEST and continued treatment for 3-12 months were included in this study. Echocardiography was analysed off-line at baseline, after 3, 6 and 12 months by investigators who were blinded to clinical data. Last and baseline observation carried forward method (LOCF, BOCF) were performed as sensitivity analysis.

RESULTS

Seventy-one patients (45% PAH, 55% CTEPH; 53.5% female; 60 ± 13 years, mean pulmonary arterial pressure 46 ± 10 mmHg, mean PVR 700 ± 282dynes·sec·cm-5) were included. After 6 months, RA and RV area, RV thickness tricuspid regurgitation velocity showed a significant reduction. After 12 months, patients receiving riociguat therapy showed a significant reduction in right atrial (- 2.6 ± 4.4 cm2, 95% CI -3.84, - 1.33; p < 0.001, n = 49) and right ventricular (RV) area (- 3.5 ± 5.2 cm2, 95% CI -5.1, - 1.9; p < 0.001; n = 44), RV thickness (- 0.76 ± 2.2 mm, 95% CI -1.55, 0.03; n = 32), and a significant increase in TAPSE (2.95 ± 4.78 mm, 95% CI 1.52, 4.39; n = 45) and RV fractional area change (8.12 ± 8.87 mm, 95% CI 4.61, 11.62; n = 27). Both LOCF and BOCF showed similar results but lower effect sizes.

CONCLUSION

Patients under long-term treatment with riociguat show significantly reduced right heart size and improved RV function in PAH and CTEPH. Further controlled prospective studies are needed to confirm these results.

Pre-operative right ventricular echocardiographic parameters associated with short-term outcomes and long-term mortality after CABG

Background This analysis aims to assess the prognostic value of pre-operative right ventricular echocardiographic parameters in predicting short-term adverse outcomes and long-term mortality after coronary artery bypass graft (CABG). Methods Study design: Observational retrospective cohort. Pre-operative echocardiographic data, perioperative adverse outcomes (POAO) and long-term mortality were retrospectively analyzed in 491 patients who underwent isolated CABG at a single academic center between 2006 and 2014. Results Average age of enrolled subjects was 66 ± 11.5 years with majority being male (69%). 227/491 patients had 30 days POAO (46%); most common being post-operative atrial fibrillation (27.3%) followed by prolonged ventilation duration (12.7%). On multivariate analysis, left atrial volume index ≥42 mL/m2 (LAVI) (OR (95% CI): 1.98 (1.03-3.82), P = 0.04), mitral E/A >2 (1.97 (1.02-3.78), P = 0.04), right atrial size >18 cm2 (1.86 (1.14-3.05), P = 0.01), tricuspid annular plane systolic excursion (TAPSE) <16 mm (1.8 (1.03-3.17), P = 0.04), right ventricular systolic pressure (RVSP) ≥36 mmHg (pulmonary hypertension) (1.6 (1.03-2.38), P = 0.04) and right ventricle myocardial performance index (RVMPI) >0.55 (1.58 (1.01-2.46), P = 0.04) were found to be associated with increased 30-day POAO. On 3.5-year follow-up, cumulative survival was decreased in patients with myocardial performance index (MPI) ≥0.55 (log rank: 4.5, P = 0.034) and in patients with mitral valve E/e' ≥14 (log rank: 4.9, P = 0.026). Conclusion Pre-operative right ventricle dysfunction (RVD) is associated with increased perioperative complications. Furthermore, pre-operative RVD and increased left atrial pressures are associated with long-term mortality post CABG.

Right ventricular enlargement predicts responsiveness to tolvaptan in congestive heart failure patients with reduced ejection fraction

Background

Tolvaptan is a vasopressin type 2 receptor antagonist used in heart failure (HF) with refractory diuretic resistance. However, since tolvaptan is also ineffective in some HF patients with reduced ejection fraction (HFrEF), the identification of responders is important.

Methods

The study population consisted of 51 HFrEF patients who were administered tolvaptan (EF, 28 ± 7%). We defined responders as patients with a ≥50% increase in urine volume during the 24-hours after administration of tolvaptan. All patients underwent comprehensive transthoracic echocardiography before administration of tolvaptan. Patients were followed for 120 days to ascertain secondary events (cardiac death and rehospitalization for HF).

Results

Multiple regression analysis indicated that right ventricular (RV) enlargement (defined as basal RV diameter > 41 mm and midlevel RV diameter > 35 mm, according to guidelines) remained a predictor of response after adjustment for age, sex, starting dosage of tolvaptan, and estimated glomerular filtration rate (odds ratio, 4.88; 95%-confidence interval, 1.26–18.9; P < 0.05), whereas left ventricular parameters and RV dysfunction were not. Kaplan-Meier curves indicated responsiveness to tolvaptan was associated with better prognosis among the overall population (P < 0.05); similar trends were observed among patients with RV dilatation (P = 0.056).

Conclusions

These findings suggest that RV enlargement, which represents right-sided volume overload, elevated filling pressure, and diastolic dysfunction similar to that seen in constrictive pericarditis, predicts responsiveness to tolvaptan in patients with HFrEF. Moreover, administration of tolvaptan may have the potential to improve the reportedly poor prognosis for HFrEF patients with RV dilatation.

The Right Heart-Pulmonary Circulation Unit: Physiopathology

The most common cause of right heart failure is increased afterload caused by pulmonary hypertension. Right ventricular function adaptation to increased afterload is basically systolic, with secondary increase in dimensions and systemic congestion. Increased right ventricular dimensions and decreased ejection fraction are associated with a decreased survival in severe pulmonary hypertension. Targeted therapies titrated to reverse the right ventricular remodeling dimensions improve survival in severe pulmonary hypertension.

The Right Heart International Network (RIGHT-NET): Rationale, Objectives, Methodology, and Clinical Implications

The Right Heart International Network is a multicenter international study aiming to prospectively collect exercise Doppler echocardiography tests of the right heart pulmonary circulation unit (RHPCU) in large cohorts of healthy subjects, elite athletes, and individuals at risk of or with overt pulmonary hypertension. It is going to provide standardization of exercise stress echocardiography of RHPCU and explore the full physiopathologic response.

Right atrial to left atrial volume index ratio is associated with increased mortality in patients with pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) is characterized by increased pulmonary vascular resistance leading to right heart failure. Elevated right atrial (RA) pressure reflects right ventricular (RV) pressure overload and is an established risk factor for mortality in PH. We hypothesized that PH patients with an increased ratio of RA to LA volume index (RAVI/LAVI), would have increased mortality.

METHODS

We evaluated the association of RAVI/LAVI with mortality in 124 patients seen at a single academic center's PH clinic after adjusting for the REVEAL risk score, an established risk score in PH. LA and RA volume indices were measured in the four-and two-chamber views by two independent researchers. Multivariable logistic regression was used to model the independent association of RAVI/LAVI with survival.

RESULTS

Among 124 patients (mean age 62 ± 12.7 years, 68.6% female), each unit increase in RAVI/LAVI was associated with a nearly twofold increase in mortality (OR: 1.91, 95% CI: 1.20-3.04). In a multivariable logistic regression, each unit increase in RAVI/LAVI was associated with a nearly twofold increase in mortality (OR: 1.73, 95% CI: 1.003-2.998). Furthermore, RAVI/LAVI in the highest quartile (>1.42) was significantly associated with elevated right atrial pressure (RAP) to pulmonary artery wedge pressure ratio (RAP/PAWP) (0.76 ± 0.41, P = 0.02) compared with the lowest quartile (<0.77), suggesting an interaction between invasive hemodynamic data, atrial structural changes, and mortality in PH.

CONCLUSIONS

Increased RAVI/LAVI in PH is associated with decreased survival and accounts for atrial structural remodeling related to invasive hemodynamics. These findings support further study of this index in predicting outcomes in PH.

Left ventricular diastolic dysfunction in patients with obesity hypoventilation syndrome

Background

Obesity hypoventilation syndrome (OHS) can be complicated by several cardiovascular conditions. We assessed the prevalence and factors associated with left ventricular diastolic dysfunction (LVDD) in patients with OHS.

Methods

In this prospective observational study, all consecutive OHS patients referred to the sleep disorders clinic between January 2002 to December 2016 were included (n=113). Demographic data, echocardiography, sleep parameters, arterial blood gases (ABGs), and lung functions were recorded.

Results

Of 113 patients with OHS who participated, 76 patients (67%) had LVDD. More than two-thirds had grade 1 LVDD. Median body mass index (BMI) was 42.8 kg/m². Median PaCO₂ was 55.8 mmHg. Median apnea hypopnea index (AHI) was 52 (25-38.5). Eighty-four (75.7%) patients were hypertensive, and 60 (54.1%) were diabetic. To minimize the effect of fluctuations in intrathoracic pressure during the obstructive respiratory events on the cardiac function, 38 OHS patients with mild to moderate OSA (AHI <30) were identified. Twenty-seven (71%) had LVDD. When compared to OHS patients without LVDD, patients with LVDD had higher BMI (47.4±6.5 versus 41.5±4.5, P=0.009). Hypertension was more common in OHS patients with LVDD than without LVDD (89.3% versus 54.5%, P=0.03). Correlation analysis revealed that hypertension (r=-0.37, P=0.016) had significant correlations with LVDD.

Conclusions

Diastolic left ventricular dysfunction is prevalent among OHS patients even in the absence of severe OSA. Hypertension and obesity were significantly more common in patients with LVDD. Assessment of diastolic dysfunction should be included in the initial evaluation of OHS patients to encourage the early institution of therapy.

Early postnatal echocardiographic assessment of pulmonary blood flow in newborns with congenital diaphragmatic hernia

Objective:

Echocardiography is the most important tool to assess infants with congenital diaphragmatic hernia (CDH) for pulmonary hypertension (PH). The pattern of blood flow in the pulmonary artery [described as time to peak velocity (TPV)/right ventricular ejection time (RVET) ratio] provides distinct information about pulmonary arterial pressure. The aim of our study was to investigate the correlation of TPV/RVET measurements with the most commonly used classification system for PH in CDH newborns and the association of these measurements with outcome parameters.

Methods:

Echocardiographic measurements were obtained in 40 CDH newborns within 6 h of life. The obtained measurements were correlated with the decision for or against extracorporeal membrane oxygenation (ECMO); early mortality; total duration of mechanical ventilation and total duration of oxygen supplementation.

Results:

The correlation coefficient between severity of PH and TPV/RVET measurements was −0.696 (P<0.001). Using receiver operating characteristic (ROC) analyses the optimal cutoff for TPV/RVET in order to predict the necessity for ECMO or early mortality without ECMO was 0.29 with a sensitivity of 86.7%, a specificity of 68%, a positive predictive value of 61.9% and a negative predictive value of 89.5%. Newborns with a TPV/RVET below the cutoff had a 5.9-fold risk for ECMO or early mortality, a significantly longer duration of mechanical ventilation (13.4 days vs. 7.4 days, P=0.003) and oxygen supplementation (22.4 days vs. 9.0 days, P=0.019), and a lower survival rate (76.2% vs. 100%, P=0.021).

Conclusions:

TPV/RVET is a feasible parameter to assess PH in CDH newborns with close correlation to outcome parameters.

Noninvasive determination of the pulmonary artery input impedance

A reliable noninvasive method for the estimation of pulmonary function in healthy and diseased subjects should be of great importance in the prognosis, diagnosis, and treatment of pulmonary hypertension. Here we propose such a method, which is based on the parameter identification of the five-element Windkessel model of pulmonary circulation. The method requires the following input variables: the heart rate, the stroke volume, the Doppler echocardiographic measurements of the tricuspid regurgitation and the pulmonary valve velocity profiles, and estimations of the right atrium and the pulmonary vein pressure. The stroke volume is calculated as a product of the left ventricle outflow tract area and the velocity-time integral measured at the same place. The model parameter identification procedure is based on minimization of the root mean square error between the pulmonary artery root pressure calculated from the aforementioned Doppler velocity profiles (from the Bernoulli equation applied during the ejection phase) and the pressure from the Windkessel model during the same period. The output from the model contains the calculated pulmonary artery input impedance (i.e. the model parameters: pulmonary vascular resistance, pulmonary artery proximal and distal compliances, inertance, and characteristic impedance) and the pulmonary artery pressure profile during the whole heart period. Our method is applied to a subject with pulmonary hypertension. The right heart Swan-Ganz catheterization has been performed in this subject. The results obtained by using this method show that the five-element Windkessel model reconstructs the main features of the pulmonary artery input impedance very well: its modulus shows the minimum where the phase angle changes its sign. The pulmonary vascular resistance, the systolic, diastolic and mean pulmonary artery pressures obtained from the method are in good agreement with the values obtained invasively from the catheterization. Sensitivity analysis shows that the mean pulmonary pressure is fairly insensitive to slight overestimation/ underestimation of all input parameters, except for the right atrium pressure. The absolute error in the mean pulmonary artery pressure is nearly the same as the error in the right atrium pressure. Since the proposed method offers a deeper insight into the pulmonary circulation than the catheterization itself because it provides the proximal and distal compliance, the inertance and the characteristic impedance, it seems that it can serve in clinical practice as a good substitute for catheterization.

Echocardiographic evaluation of the right ventricular dimension and systolic function in dogs with pulmonary hypertension

Background

Right ventricular (RV) enlargement and dysfunction are associated with prognosis in humans with pulmonary hypertension (PH).

Hypothesis/Objectives

To assess RV size and systolic function in dogs with PH and to determine if they are associated with disease severity and right‐sided congestive heart failure (R‐CHF).

Animals

89 dogs with PH and 74 healthy dogs.

Methods

Prospective observational study. PH was classified according to the tricuspid regurgitation pressure gradient. RV end‐diastolic area (RVEDA) index was calculated as RVEDA divided by body surface area. RV systolic function was assessed with the tricuspid annular plane systolic excursion (TAPSE) and the RV fractional area change (FAC) normalized for body weight (TAPSEn and FACn, respectively).

Results

RVEDA index was higher in dogs with moderate PH (10.8 cm²/m²; range, 6.2‐14.4 cm²/m²) and severe PH (12.4 cm²/m²; range, 7.7‐21.4 cm²/m²) than in those with mild PH (8.4 cm²/m²; range, 4.8‐11.6 cm²/m²) and control dogs (8.5 cm²/m²; range, 2.8‐11.6 cm²/m²; P < .001). RVEDA index was significantly higher in dogs with R‐CHF (13.7 cm²/m²; range, 11.0‐21.4 cm²/m²) than in dogs without R‐CHF (9.4 cm²/m²; range, 4.8‐17.1 cm²/m²; P < .001). The severity of tricuspid regurgitation (TR) was the only independent predictor of the RVEDA index (P < .001). TAPSEn and FACn were not significantly different among varying degrees of PH severity and between dogs with and without R‐CHF.

Conclusions and Clinical Importance

The RVEDA index can be used to evaluate RV size in dogs. It can provide additional information in dogs with PH and predict R‐CHF. Severity of TR is the main determinant of RV enlargement in dogs with PH.

"Low-" versus "high"-frequency oscillation and right ventricular function in ARDS. A randomized crossover study

Background

Recent, large trials of high-frequency oscillation (HFO) versus conventional ventilation (CV) in acute respiratory distress syndrome (ARDS) reported negative results. This could be explained by an HFO-induced right ventricular (RV) dysfunction/failure due to high intrathoracic pressures and hypercapnia. We hypothesized that HFO strategies aimed at averting/attenuating hypercapnia, such as "low-frequency" (i.e., 4 Hz) HFO and 4-Hz HFO with tracheal-gas insufflation (HFO-TGI), may result in an improved RV function relative to "high-frequency" (i.e., 7 Hz) HFO (which may promote hypercapnia) and similar RV function relative to lung protective CV.

Methods

We studied 17 patients with moderate-to-severe ARDS [PaO₂-to-inspiratory O₂ fraction ratio (PaO₂/FiO₂) < 150]. RV function was assessed by transesophageal echocardiography (TEE). Patients received 60 min of CV for TEE-guided, positive end-expiratory pressure (PEEP) "optimization" and subsequent stabilization; 60 min of 4-Hz HFO for "study mean airway pressure (mPaw)" titration to peripheral oxygen saturation ≥ 95%, without worsening RV function as assessed by TEE; 60 min of each tested HFO strategy in random order; and another 60 min of CV using the pre-HFO, TEE-guided PEEP setting. Study measurements (i.e., gas exchange, hemodynamics, and TEE data) were obtained over the last 10 min of pre-HFO CV, of each one of the three tested HFO strategies, and of post-HFO CV.

Results

The mean "study HFO mPaw" was 8-10 cmH₂O higher relative to pre-HFO CV. Seven-Hz HFO versus 4-Hz HFO and 4-Hz HFO-TGI resulted in higher mean ± SD right-to-left ventricular end-diastolic area ratio (RVEDA/LVEDA) (0.64 ± 0.15 versus 0.56 ± 0.14 and 0.52 ± 0.10, respectively, both p < 0.05). Higher diastolic/systolic eccentricity indexes (1.33 ± 0.19/1.42 ± 0.17 versus 1.21 ± 0.10/1.26 ± 0.10 and 1.17 ± 0.11/1.17 ± 0.13, respectively, all p < 0.05). Seven-Hz HFO resulted in 18-28% higher PaCO₂ relative to all other ventilatory strategies (all p < 0.05). Four-Hz HFO-TGI versus pre-HFO CV resulted in 15% lower RVEDA/LVEDA, and 7%/10% lower diastolic/systolic eccentricity indexes (all p < 0.05). Mean PaO₂/FiO₂ improved by 77-80% during HFO strategies versus CV (all p < 0.05). Mean cardiac index varied by ≤ 10% among strategies. Percent changes in PaCO₂ among strategies were predictive of concurrent percent changes in measures of RV function (R² = 0.21-0.43).

Conclusions

In moderate-to-severe ARDS, "short-term" 4-Hz HFO strategies resulted in better RV function versus 7-Hz HFO, partly attributable to improved PaCO₂ control, and similar or improved RV function versus CV.

Trial registration

This study was registered 40 days prior to the enrollment of the first patient at ClinicalTrials.gov, ID no. NCT02027129, Principal Investigator Spyros D. Mentzelopoulos, date of registration January 3, 2014.

Focused Cardiac Ultrasound Determines Cause of Cardiovascular Collapse During Thoracic Surgery in a Patient With Undiagnosed Pulmonary Hypertension: A Case Report

Patients with severe pulmonary hypertension (PHT) represent a high-risk population when undergoing noncardiac surgery. During thoracic surgery with 1-lung ventilation, atelectasis of the operative lung, and frequently associated hypoxemia, is likely to exacerbate PHT and precipitate acute right ventricular failure. We present a patient with previously undiagnosed PHT who suffered 2 cardiac arrests during emergent thoracic surgery for empyema. After successful resuscitation in the operating room, she subsequently required prolonged venoarterial extracorporeal membrane oxygenation. Focused transthoracic echocardiography to evaluate cardiac function was critical in the diagnosis of PHT and subsequent treatment with sildenafil and nifedipine when discharged from the hospital.

Echocardiographic assessment of pulmonary hypertension: a guideline protocol from the British Society of Echocardiography

Pulmonary hypertension is defined as a mean arterial pressure of ≥25 mmHg as confirmed on right heart catheterisation. Traditionally, the pulmonary arterial systolic pressure has been estimated on echo by utilising the simplified Bernoulli equation from the peak tricuspid regurgitant velocity and adding this to an estimate of right atrial pressure. Previous studies have demonstrated a correlation between this estimate of pulmonary arterial systolic pressure and that obtained from invasive measurement across a cohort of patients. However, for an individual patient significant overestimation and underestimation can occur and the levels of agreement between the two is poor. Recent guidance has suggested that echocardiographic assessment of pulmonary hypertension should be limited to determining the probability of pulmonary hypertension being present rather than estimating the pulmonary artery pressure. In those patients in whom the presence of pulmonary hypertension requires confirmation, this should be done with right heart catheterisation when indicated. This guideline protocol from the British Society of Echocardiography aims to outline a practical approach to assessing the probability of pulmonary hypertension using echocardiography and should be used in conjunction with the previously published minimum dataset for a standard transthoracic echocardiogram.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Inflammasomes: a novel therapeutic target in pulmonary hypertension?

Pulmonary hypertension (PH) is a rare, progressive pulmonary vasculopathy characterized by increased mean pulmonary arterial pressure, pulmonary vascular remodelling and right ventricular failure. Current treatments are not curative, and new therapeutic strategies are urgently required. Clinical and preclinical evidence has established that inflammation plays a key role in PH pathogenesis, and recently, inflammasomes have been suggested to be central to this process. Inflammasomes are important regulators of inflammation, releasing the pro-inflammatory cytokines IL-1β and IL-18 in response to exogenous pathogen- and endogenous damage-associated molecular patterns. These cytokines are elevated in PH patients, but whether this is a consequence of inflammasome activation remains to be determined. This review will briefly summarize current PH therapies and their pitfalls, introduce inflammasomes and the mechanisms by which they promote inflammation and, finally, highlight the preclinical and clinical evidence for the potential involvement of inflammasomes in PH pathobiology and how they may be targeted therapeutically. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Practical guidance for the implementation of stress echocardiography

Exercise stress testing has been widely undertaken for the diagnosis of heart diseases. The accurate assessment of clinical conditions can be conducted by comparing the findings obtained from the results of stress echocardiography with the changes in the blood/heart rate and electrocardiograms. Numerous overseas studies have reported the utility of stress echocardiography in diagnosing myocardial ischemia; in Japan, the use of this modality for this purpose was included in the national health insurance reimbursable list in 2012. Nevertheless, stress echocardiography is far from being a widespread practice in Japan. This might be due to insufficient equipment (e.g., ergometers, space for test implementation) at each medical institution, shortage of technicians and sonographers who are well experienced and who are responsible for obtaining images during stress testing. The other possible reasons include the limited evidence available in Japan and the lack of a standardized testing protocol. Further dissemination of the practice of exercise stress echocardiography in this country is deemed necessary to establish satisfactory evidence for the use of stress echocardiography in the Japanese population. To this end, efforts are underway to develop a standardized protocol and report format to be adopted throughout Japan. We here present a guideline created by the Guideline Development Committee of the Japanese Society of Echocardiography that describes safe and effective stress echocardiography protocols and report formats. The readers are encouraged to perform exercise stress echocardiography using the proposed template for consensus document and report attached to this guideline.

Approach to pulmonary vascular disease in the ICU

PURPOSE OF REVIEW

Pulmonary vascular disease (PVD) complicates the course of many cardiovascular, pulmonary and other systemic diseases in children. The physiological sequelae (pulmonary hypertension and elevated pulmonary vascular resistance) can overwhelm the right ventricle and lead to circulatory collapse. Despite the common end-point, the preceding pathophysiology is complex and variable and requires a tailored approach to diagnosis and management. In this article, we will review the most recent evidence and explore an approach to current controversies in the diagnosis and management of common or challenging patient subgroups.

RECENT FINDINGS

New methods of interpreting data derived from echocardiography and cardiac magnetic resonance imaging may assist in risk stratification and response to therapy. In specific patient subgroups, standard pharmacological therapies to reduce right ventricle afterload may be overutilized, ineffective and in some cases harmful. In the patient failing pharmacological therapy, new and novel techniques are being explored including temporary extracorporeal mechanical circulatory support, pumpless lung assist devices and novel surgical and catheterization procedures.

SUMMARY

PVD is a diverse entity, and attention to the underlying pathophysiology is essential for appropriate management. Despite significant advances in our understanding, the majority of data comes from small uncontrolled studies and must be interpreted with caution.

E/E' and D-shaped Left Ventricle Severity in Patients with Increased Pulmonary Artery Pressure

BACKGROUND

D-shaped left ventricle (D-LV) is an interesting echocardiographic finding in pulmonary hypertension (PH) and is the result of structural distortion of the interventricular septum. The eccentricity index (EI) is a quantitative measure used to evaluate the severity of D-LV in patients with increased pulmonary artery pressure (PAP). However, D-LV and EIs have rarely been studied in terms of their association with hemodynamic factors.

METHODS

A total of 526 patients with a maximal tricuspid regurgitation velocity (VmaxTR) > 2.8 m/s on echocardiography identified between January 2012 and December 2017 were enrolled. After exclusion, a total of 289 patients were analyzed. The association between D-LV and hemodynamic factors were analyzed using logistic regression. Furthermore, factors that impacted the severity of the D-LV, as defined by EIs, were also analyzed using the multiple linear regression model.

RESULTS

In the multivariate logistic regression model, higher pulmonary artery pressure (PAP, p = 0.001), lower tricuspid annular plane systolic excursion (TAPSE, p = 0.048), and E/E' (p = 0.017) were found to be significant risk factors for the presence of D-LV. Additional analysis with age and body mass index added to independent variables, PAP (p = 0.008), TAPSE (p = 0.028), and age (p < 0.001) were significant risk factors for the presence of D-LV. In patients with D-LV, only E/E' was independently associated with EIs (R2 = 0.666, p < 0.001).

CONCLUSIONS

In patients with increased PAP, D-LV is associated with PAP, TAPSE, E/E', and age. EIs are associated with left ventricular filling pressure, represented as E/E'.

Echocardiographic parameters to identify sickle cell patients with cardio-pathology

BACKGROUND

Sickle cell disease (SCD) affects millions of people and causes chronic hemolytic anemia leading to vasculopathies such as pulmonary hypertension and abnormalities in cardiac function that increase complications and mortality. It is therefore crucial to identify cardiac abnormalities in SCD. We aimed to assess the prevalence of echocardiographic parameters in SCD to help identify cardiopulmonary risk.

METHODS

Ninety-one patients (53% male), median age of 30, body surface area (BSA) of 1.79 m² , hemoglobin of 8.8 g/dL, and creatinine of 0.7 mg/dL identified. We retrospectively measured laboratory and echocardiographic parameters in patients with SCD : left ventricular (LV) dimensions, LV ejection fraction (LVEF), LV Myocardial Performance Index (MPI), LV Mass Index (MI), Left Atrial Volume Index (LAVI), Tricuspid Regurgitation Velocity (TRV), tricuspid annular plane systolic excursion (TAPSE), right heart dimensions.

RESULTS

Prevalence of left heart abnormalities was 32%: increased LV end-diastolic diameter (EDD), 78%: LV MPI, 21%: diastolic dysfunction, 38%: decreased LVEF, 24%: increased LVMI, and 47%: increased LAVI. Right heart abnormalities were 39%: TAPSE, 38%: increased TRV, and 59%: increased pulmonary systolic pressure (PASP). Multivariate logistic regression analysis was significant for increased LVMI and LAVI in those with hemoglobin ≤8 g/dL (odds ratio (OR) 7.4, 95% confidence interval (CI) 2.23-24.6, P = .001) and (OR 3.32, 95% CI 1.18-9.33, P = .023).

CONCLUSIONS

We confirmed increased prevalence of abnormal LVEDD, LVMI, diastolic function, LAVI, and PASP in SCD. In addition, we identified abnormal LV MPI (78%), TAPSE (29%). These parameters may be useful and readily accessible echocardiographic prognostic tools in this population.

Pulmonary vascular resistance determines mortality in end-stage renal disease patients with pulmonary hypertension

The multifactorial etiology of pulmonary hypertension (PH) in end-stage renal disease (ESRD) includes patients with and without elevated pulmonary vascular resistance (PVR). We explored the prognostic implication of this distinction by evaluating pretransplant ESRD patients who underwent right heart catheterization and echocardiography. Demographics, clinical data, and test results were analyzed. All-cause mortality data were obtained. Median follow-up was 4 years. Of the 150 patients evaluated, echocardiography identified 99 patients (66%) with estimated pulmonary artery (PA) systolic pressure > 36 mm Hg, which correlated poorly with mortality (HR = 1.28, 95% CI 0.72-2.27, P = .387). Right heart catheterization identified 88 (59%) patients with mean PA pressure ≥ 25 mm Hg. Of these, 70 had PVR ≤ 3 Wood units and 18 had PVR > 3 Wood units. Survival analysis demonstrated a significant prognostic effect of an elevated PVR in patients with high mean PA pressures (HR = 2.26, 95% CI 1.07-4.77, P = .03), while patients with high mean PA pressure and normal PVR had equivalent survival to those with normal PA pressure. Despite the high prevalence of PH in ESRD patients, elevated PVR is uncommon and is a determinant of prognosis in patients with PH. Patients with normal PVR had survival equivalent to those with normal PA pressures.

Reference values and correlates of right atrial volume in healthy adults by two-dimensional echocardiography

BACKGROUND

Right atrial (RA) volume is an important parameter in the evaluation of patients with pulmonary hypertension. Aim of this study was to define reference ranges for RA volume by two-dimensional echocardiography (2DE) in healthy adults.

METHODS

A total of 596 healthy subjects [mean age 45.7 ± 14.6 years, range 18-88 years; 60.1% women] underwent a transthoracic echocardiography. In addition, a meta-analysis was performed of published studies measuring RA volume in healthy subjects, using 2DE single plane area-length (A-L) and/or method of disks (MOD) at end-systole in apical four-chamber view.

RESULTS

In our cohort, RA volume was higher in men than women but did not vary with age. Body surface area (BSA), stroke volume (SV), and tricuspid annular plane systolic excursion (TAPSE) were the only independent variables associated with RA volume (β coefficient 0.569, 0.123, and 0.131, respectively; all P < .001). In the pooled analysis, normalized RA volume was 25.7 ± 7.0 mL/m² in men and 21.2 ± 5.8 mL/m² in women for A-L, 21.6 ± 5.6 mL/m² in men and 18.2 ± 5.4 mL/m² in women for MOD (all P values < .0001). The upper limit was about 36 mL/m² in men and 31 mL/m² in women for A-L and 31 mL/m² in men and 27 mL/m² in women for MOD.

CONCLUSIONS

RA volume was found to be higher in men but not influenced by age. It was mainly correlated with larger BSA, indices of preload (SV) and RV longitudinal function (TAPSE). A statistically significant difference was found between A-L and MOD.

Noninvasive pulmonary arterial pressure estimation using a logistic-based systolic model

RATIONALE

A hemodynamic relationship of pulmonary artery pressure (PAP) to pulmonary acceleration time (PAcT) has not yet been explicitly presented.

OBJECTIVE

We employed a logistic-based systolic model with a subtle modification for pulmonary circulation and provided a logical ground for the relationship between systolic PAP and PAcT using transthoracic echocardiography. Additionally, the logistic-based PAP estimation equation was deduced from the model to relate systolic PAP and PAcT.

METHODS AND RESULTS

This equation was statistically tested in comparison to existing PAP estimation equations. Results showed that the logistic-based PAP estimation equation was at least as accurate as previous equations with respect to previously published mean PAP versus PAcT values. After the subtle pulmonary modification of the model, the pulmonary blood flow velocity and pressure not only well reflected the underlying pulmonary circulation physiology, but could also be presented in harmony with systemic circulation physiology.

CONCLUSIONS

A future clinical study with actual systolic PAP versus PAcT measurements is needed to test the application of the logistic-based PAP estimation equation.

Sensitive Cardiac Troponins: Could They Be New Biomarkers in Pediatric Pulmonary Hypertension Due to Congenital Heart Disease?

To analyze the role of sensitive cardiac troponin I (scTnI) and high-sensitive troponin T (hscTnT) in the determination of myocardial injury caused by volume and pressure load due to pulmonary hypertension (PH) and to investigate if these markers may be useful in the management of PH in childhood. Twenty-eight patients with congenital heart disease (CHD) with left to right shunt and PH, 29 patients with CHD with left to right shunt but without PH, and 18 healthy children, in total 75 individuals, were included in the study. All cases were aged between 4 and 36 months. Echocardiographic evaluation was performed in all cases, and invasive hemodynamic investigation was performed in 33 cases. Blood samples were obtained from all cases, for the measurement of brain natriuretic peptide (BNP), pro-brain natriuretic peptide (pro-BNP), sensitive cardiac troponin I (scTnI), and high-sensitive troponin T (hscTnT) levels. The mean BNP, pro-BNP, scTnI, and hsTnT levels were statistically significantly higher in patients with PH than in the patients without PH (p < 0.001). A statistically significant positive correlation was determined between pulmonary artery systolic pressure and scTnI and hscTnT levels (r = 0.34 p = 0.01, r = 0.46 p < 0.001, respectively) levels. Pulmonary hypertension determined in congenital heart diseases triggers myocardial damage independently of increased volume or pressure load and resistance, occurring by disrupting the perfusion via increasing ventricular wall tension and the myocardial oxygen requirement. Serum scTnI and hscTnT levels may be helpful markers to determine the damage associated with PH in childhood.

Urocortin-2 improves right ventricular function and attenuates pulmonary arterial hypertension

Aims

Pulmonary arterial hypertension (PAH) is a devastating disease and treatment options are limited. Urocortin-2 (Ucn-2) has shown promising therapeutic effects in experimental and clinical left ventricular heart failure (HF). Our aim was to analyse the expression of Ucn-2 in human and experimental PAH, and to investigate the effects of human Ucn-2 (hUcn-2) administration in rats with monocrotaline (MCT)-induced pulmonary hypertension (PH).

Methods and results

Tissue samples were collected from patients with and without PAH and from rats with MCT-induced PH. hUcn-2 (5 μg/kg, bi-daily, i.p., for 10 days) or vehicle was administered to male wistar rats subjected to MCT injection or to pulmonary artery banding (PAB) to induce right ventricular (RV) overload without PAH. Expression of Ucn-2 and its receptor was increased in the RV of patients and rats with PAH. hUcn-2 treatment reduced PAH in MCT rats, resulting in decreased morbidity, improved exercise capacity and attenuated pulmonary arterial and RV remodelling and dysfunction. Additionally, RV gene expression of hypertrophy and failure signalling pathways were attenuated. hUcn-2 treatment also attenuated PAB-induced RV hypertrophy.

Conclusions

Ucn-2 levels are altered in human and experimental PAH. hUcn-2 treatment attenuates PAH and RV dysfunction in MCT-induced PH, has direct anti-remodelling effects on the pressure-overloaded RV, and improves pulmonary vascular function.

Sarcoidosis-associated Pulmonary Hypertension: Pathophysiology, Diagnosis, and Treatment

Clinicians in pulmonary medicine frequently confront the challenge of screening, diagnosis and management of pulmonary hypertension (PH) in sarcoidosis patients who present with unexplained dyspnea. Sarcoidosis associated pulmonary hypertension (SAPH) is most prevalent in patients with pulmonary fibrosis, though it can be independent of airflow obstruction or restriction. SAPH independently associates with significantly increased mortality and decreased functional capacity, outcomes which can be mitigated by early detection and focused treatment. In this review, we discuss the pathophysiology of SAPH, which may resemble pulmonary arterial hypertension as well as secondary causes of PH. We offer a screening algorithm for SAPH, and advocate for detailed assessment of the cause of PH in each patient prior to choice of an individualized treatment plan. We note that treatment of sarcoidosis via immune suppression is typically insufficient to adequately treat SAPH. We discuss secondary causes of SAPH such as left heart disease, sleep disordered breathing, and thromboembolic disease, and the evidence for use of PH-specific therapy in select cases of SAPH. Management of SAPH by clinicians experienced in PH, with early referral to transplantation in refractory cases is advised.

Impact of systolic pulmonary artery pressure on all-cause mortality in elderly cardiac patients

OBJECTIVE

Elevated systolic pulmonary artery pressure (sPAP) is common among elderly patients with cardiac and pulmonary diseases. The lowest level of sPAP associated with increased mortality rate in octogenarians with cardiac diseases is however not sufficiently studied. Therefore, the present study aimed to identify the lowest level of sPAP associated with increased 5-year all-cause mortality in this patient group.

DESIGN

Of 538 octogenarians presented at the three Sahlgrenska University Hospitals (Sahlgrenska, Östra and Mölndal) with either congestive heart failure (CHF) or acute coronary syndrome (ACS), only 302 patients who had undergone echocardiography with data on sPAP were included in the present study. In order to identify the lowest level of sPAP associated with increased mortality rate, Cox proportional-hazard regression multivariable models were built for sPAP levels as low as 30 mmHg and upward with 5 mmHg intervals.

RESULTS

sPAP >35 mmHg was identified as the lowest level associated with increased 5-year all-cause mortality (HR = 1.7, 95% of CI = 1.1-2.6 and p = .013). Every increase of 5 mmHg in sPAP was associated with a 10% increased relative risk for all-cause mortality.

CONCLUSIONS

In octogenarians with cardiac diseases the lowest level of sPAP associated with increased all-cause mortality was >35 mmHg and the mortality rate increased with increasing sPAP.

Is there a learning effect when the 6-minute walk test is repeated in people with suspected pulmonary hypertension?

The aim of the study was to determine if there was a difference in 6-minute walk distance (6MWD) when two 6-minute walk tests (6MWTs) were performed at the initial assessment prior to attendance at the pulmonary hypertension (PH) clinic and at the 6-month follow-up. Two 6MWTs were performed at both visits on a 32-m continuous track in the physiotherapy hospital outpatient setting using standard instructions and encouragement. Two hundred and fourteen participants completed two 6MWTs at the initial assessment and 71 participants at the 6-month follow-up (mean (standard deviation) age: 57 (16) years; body mass index: 27 (6) kg/m²). Using the better 6MWT, the mean distances walked were 429 (136) and 447 (130) m, respectively. There was a significant increase in 6MWD when a second 6MWT was performed at initial assessment (mean difference [95% confidence interval (CI)]: 19 m (14–24), p < 0.001) and at the follow-up (mean difference [95% CI]: 19 m (10–27), p < 0.001) but not in those who walked <300 m at the initial assessment (mean difference [95% CI]: 9 m (−5 to 22), p = 0.208). There were no adverse events during testing. Prior to attendance at the PH Clinic when people are asked to perform the 6MWT for the first time and at the 6-month follow-up, two walk tests should be performed in order to eliminate a learning effect and to ensure accuracy of measurement.

Echocardiographic validation of pulmonary hypertension due to heart failure with reduced ejection fraction in mice

Pulmonary hypertension (PH) associated with left heart diseases is the most prevalent cause of PH. The scarcity of studies exploring the pathophysiology and therapies of group II PH resides in the lack of validated small animal models with non-invasive determination of the presence and severity of PH. Heart failure (HF) was induced in mice by coronary artery ligation. Mice developed PH as evidenced by an elevated right ventricular (RV) systolic pressure and RV hypertrophy. Detailed non-invasive echocardiographic analysis on the left and right ventricles showed impaired left ventricular (LV) systolic and diastolic function. In addition, RV hypertrophy was confirmed by echo and accompanied by impaired function as well as increased pulmonary resistance. Correlation analysis validated the use of the LV wall-motion score index (WMSI) at a threshold value of ≥2.0 as a powerful and reliable indicator for the presence of PH and RV dysfunction. Echocardiography is an accurate non-invasive technique to diagnose PH in a HF mouse model. Moreover, an echocardiographic parameter of infarct size and LV function, the LV WMSI, reliably correlates with the presence of PH, RV hypertrophy and RV dysfunction and could be used to improve efficiency and design of pre-clinical studies.