Clinical correlates and reference intervals for pulmonary artery systolic pressure among echocardiographically normal subjects

Flow-related right ventricular to pulmonary arterial pressure gradients during exercise

Aims

The assumption of equivalence between right ventricular (RV) and pulmonary arterial systolic pressure is fundamental to several assessments of RV or pulmonary vascular haemodynamic function. Our aims were to (i) determine whether systolic pressure gradients develop across the RV outflow tract in healthy adults during exercise, (ii) examine the potential correlates of such gradients, and (iii) consider the effect of such gradients on calculated indices of RV function.

Methods and results

Healthy untrained and endurance-trained adult volunteers were studied using right-heart catheterization at rest and during submaximal cycle ergometry. RV and pulmonary artery (PA) pressures were simultaneously transduced, and the cardiac output was determined by thermodilution. Systolic pressures, peak and mean gradients, and indices of chamber, vascular, and valve function were analysed offline. Summary data are reported as mean ± standard deviation or median (interquartile range). No significant RV outflow tract gradients were observed at rest [mean gradient = 4 (3–5) mmHg], and the calculated effective orifice area was 3.6 ± 1.0 cm2. The increase in right ventricular systolic pressure during exercise was greater than the PA systolic pressure. Accordingly, mean gradients were developed during light exercise [8 (7–9) mmHg] and increased during moderate exercise [12 (9–14) mmHg, P < 0.001]. The magnitude of the mean gradient was linearly related to the cardiac output (r2 = 0.70, P < 0.001).

Conclusions

In healthy adults without pulmonic stenosis, systolic pressure gradients develop during exercise, and the magnitude is related to the blood flow rate.

Severe heart failure (NYHA Class IV) is associated with increased left ventricular mass index and short mitral deceleration time in severe aortic valve stenosis

BACKGROUND

In aortic valve stenosis (AS), congestive heart failure (CHF) is a well-established symptom that indicates the need for surgical aortic valve replacement (SAVR). However, it is difficult to judge whether CHF symptoms such as dyspnea are caused by severe AS or other conditions, especially in elderly persons with restricted mobility or other organ complications. It is important to identify objective and noninvasive parameters associated with severe CHF symptoms in severe AS.

METHODS

One hundred ninety-eight patients with severe AS without left ventricular (LV) dysfunction were retrospectively studied. CHF symptoms were classified by New York Heart Association (NYHA) functional class. Echo parameters were compared between NYHA I-III and NYHA IV.

RESULTS

Patients with NYHA IV (n = 40; 20%) were older (86 ± 6 vs 82 ± 8 years; P = .001) and had a larger LV mass index (LVMI) (157 ± 43 vs 114 ± 34 g/m² , P < .001), a higher transmitral flow velocity ratio (E/A) (1.31 ± 0.62 vs 0.93 ± 0.42; P = .001), a shorter deceleration time (DT) (202 ± 72 vs 286 ± 98 ms; P < .001), and a higher systolic pulmonary arterial pressure (SPAP) (44 ± 13 vs 35 ± 13 mm Hg; P < .001) than patients with NYHA I-III. On multivariable analysis, LVMI and DT were independently associated with NYHA IV. Receiver operating characteristic curve analysis identified LVMI ≥ 142 g/m² and DT ≤ 194 ms as the cutoff values associated with NYHA IV in patients with severe AS.

CONCLUSION

Left ventricular mass index and DT were independently associated with severe heart failure (NYHA IV). These echo parameters could be helpful to judge whether CHF symptoms are caused by severe AS.

Epidemiology and risk factors in CKD patients with pulmonary hypertension: a retrospective study

BACKGROUND

Pulmonary hypertension (PH) is a rare disease often associated with high mortality and is recently recognized as a common complication secondary to chronic kidney disease (CKD). Epidemiological data for this disorder across the spectrum of CKD is poorly understood.

METHODS

We retrospectively analyzed 705 CKD patients with complete clinical records from July 2013 to September 2015. All the patients were estimated by echocardiography and PH was defined as pulmonary artery systolic pressure (PASP) > 35 mmHg. The prevalence of PH in CKD patients was investigated, and their association was evaluated with a logistic regression model.

RESULTS

The overall prevalence of PH was 47.38%, in which mild, moderate and severe PH accounted for 22.13, 15.04 and 10.21%, respectively. The prevalence of PH in CKD stage 1-5 was 14.29, 33.33, 38.89, 40.91 and 64.47%. The prevalence of total PH was 57.63% in PD patients and 58.82% in HD patients. Compared with the non-dialysis patients, the prevalence of PH was much higher in patients receiving dialysis. Body mass index (BMI), hemoglobin, triglyceride (TG), proteinuria, parathyroid hormone (PTH) and estimated glomerular filtration rate (eGFR) were independent risk factors of PH in CKD patients.

CONCLUSIONS

The prevalence of PH is increased with the deterioration of renal function, however, which has no direct relation to the severity of PH. PH occurs more frequently in dialysis patients. Higher BMI and TG, more sever anemia, proteinuria and secondary hyperparathyroidism, poor renal dysfunction predict predict the more prevalence of PH in CKD patients.

The right ventricular outflow tract in pediatric pulmonary hypertension-Data from the European Pediatric Pulmonary Vascular Disease Network

OBJECTIVE

The right ventricular outflow tract (RVOT) is pivotal for adequate RV function and known to be adversely affected by elevated pulmonary arterial pressure (PAP) in adults with pulmonary hypertension (PH). Aim of this study was to determine the effects of increased RV pressure afterload in children with PH on RVOT size, function, and flow parameters.

METHODS

We conducted a transthoracic echocardiographic study in 51 children with PH (median age: 5.3 years; range 1.5 months to 18 years) and determined the following RVOT variables: RVOT diameter, RVOT velocity time integral (VTI), ratio of tricuspid regurgitation velocity (TRV)/RVOT VTI, and RVOT systolic excursion (SE).

RESULTS

In our pediatric PH cohort, the age-specific RVOT diameter z-score was higher compared to normal values. Deviation from normal RVOT diameter values increased with age, disease severity, and New York Heart Association functional class. Significant correlations were found between RVOT diameter and the RV end-diastolic area and right atrial area. The age-specific RVOT VTIz-score values were significantly lower in children with PH vs healthy controls. The TRV/RVOT VTI ratio increased with rising systolic RV pressure, while the RVOT SE was similar between PH children and control subjects.

CONCLUSIONS

In pediatric PH cohort, the RVOT VTI is decreased, and the TRV/RVOT VTI ratio and the RVOT diameter increased compared to healthy subjects. Assessment of RVOT variables, together with established RV parameters, allows for a comprehensive assessment of global right heart size and performance in children with PH.

Is universal grading of diastolic function by echocardiography feasible?

Quantitation of diastolic function centers on the assessment of active and passive ventricular properties, and involves measurement estimates of ventricular relaxation, and chamber and myocardial stiffness. Diastolic dysfunction is a propensity to develop increased left ventricular (LV) end-diastolic pressure. Recently American Society of Echocardiography and European Association of Cardiovascular Imaging (ASE/EACVI) proposed a new grading system. While the new guidelines are ambiguous and with cutoff points that may misclassify patients as both sicker and healthier than they are. This article outlines the pathophysiology behind the diastolic dysfunction and role and limitation of echocardiographic assessment in predicting LV diastolic dysfunction.

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.

Neural respiratory drive and cardiac function in patients with obesity hypoventilation syndrome following initiation of non-invasive ventilation

Background

Chronic hypercapnic respiratory failure (HRF) in obesity hypoventilation syndrome (OHS) is commonly treated using non-invasive ventilation (NIV). We hypothesised that treatment of OHS would improve neural respiratory drive index (NRDI) and cardiac function.

Methods

Fourteen patients (8 females) with OHS, who were admitted for initiation of domiciliary NIV, were prospectively studied. Patients had (mean ± SD): age (53±10 years), body mass index (BMI) (50.1±10.8 kg/m²), and pCO₂ (7.3±0.9 kPa). NRDI was assessed by surface electromyogram of the parasternal intercostals. Cardiac function was assessed by transthoracic echocardiography (TTE). All measurements were performed at baseline, 6 weeks, and 3 months.

Results

NRDI improved on day one following NIV set-up comparing to baseline (484.2±214.8 vs. 316.5±106.5 AU) and this improvement was maintained at 6 weeks (369.1±173.2 AU) and at 3 months (351.2±167.1 AU) (P=0.004). No significant differences were identified in terms of cardiac function between baseline and 3 months [tricuspid annular plane systolic excursion (TAPSE) (24.6±5.8 vs. 23.0±4.0 mm, P=0.317); systolic pulmonary artery (PA) pressures (36.7±15.2 vs. 44.5±23.9 mmHg, P=0.163].

Conclusions

NIV improves NRDI in patients with OHS, while the cardiac function over a three-month period remains unchanged.

Does Pulmonary Artery Systolic Pressure as Estimated by Transthoracic Echocardiography Alter the Effect of Positive End-Expiratory Pressure on Arterial Blood Gases and Hemodynamics in Morbidly Obese Patients?

Background

Positive end-expiratory pressure (PEEP) at the time of induction increases oxygenation by preventing lung atelectasis. However, PEEP may not prove beneficial in all cases. Factors affecting the action of PEEP have not been elucidated well and remain controversial. Pulmonary vasculature has direct bearing on the action of PEEP as has been proven in the previous studies. Thus, this prospective study was planned to evaluate the action of PEEP on the basis of pulmonary artery systolic pressure (PASP) which is noninvasive and easily measured by transthoracic echocardiography.

Materials and Methods

Seventy morbidly obese patients, the American Society of Anesthesiologists Grade II, or III, aged 20-65 years with body mass index >40 kg/m², scheduled for elective laparoscopic bariatric surgery were included. Patients who denied consent, those undergoing emergency and/or open surgery and those requiring >2 attempts for intubation were excluded from the study. Ten patients had to be excluded. Thus, a total of sixty patients participated in the study. Thirty patients received no PEEP at the time of induction while other thirty patients were given a PEEP of 10 cm of H₂O. Serial ABG samples were taken preoperatively, at the time of intubation, 5 min after intubation, and 10 min after intubation. Patients were then divided into four groups on the basis of PASP value of ≤30 mm Hg with and without PEEP or >30 mm Hg with and without PEEP.

Primary Outcome

The primary outcome was the effect of PEEP of 10 cm of H2 O on ABG and hemodynamics in morbidly obese patients.

Secondary Outcome

The secondary outcome was the effect of PASP on the action of PEEP in morbidly obese patients undergoing laparoscopic surgery.

Results

Patients having PASP of >30 mm Hg had significant improvement in oxygenation on PEEP application (270.11 ± 119.26 mm Hg) as compared to those without PEEP (157.57 ± 109.29 mm Hg) just after intubation. The increase in oxygenation remained significant at all time intervals. Patients with PASP ≤30 mm Hg did not show significant improvement in oxygenation with PEEP application (177.09 ± 85.85 mm Hg as compared to 226.27 ± 92.42 mm Hg without PEEP). Hemodynamic parameters did not show statistically significant alterations.

Conclusion

Morbidly obese patients who have PASP >30 mm Hg benefit most from the PEEP. Thus, PASP which is an easily measurable noninvasive parameter can be used as a criterion for selecting patients who benefit from PEEP application.

The Intersection of Aging Biology and the Pathobiology of Lung Diseases: A Joint NHLBI/NIA Workshop

Death from chronic lung disease is increasing and chronic obstructive pulmonary disease has become the third leading cause of death in the United States in the past decade. Both chronic and acute lung diseases disproportionately affect elderly individuals, making it likely that these diseases will become more frequent and severe as the worldwide population ages. Chronic lung diseases are associated with substantial morbidity, frequently resulting in exercise limiting dyspnea, immobilization, and isolation. Therefore, effective strategies to prevent or treat lung disease are likely to increase healthspan as well as life span. This review summarizes the findings of a joint workshop sponsored by the NIA and NHLBI that brought together investigators focused on aging and lung biology. These investigators encouraged the use of genetic systems and aged animals in the study of lung disease and the development of integrative systems-based platforms that can dynamically incorporate data sets that describe the genomics, transcriptomics, epigenomics, metabolomics, and proteomics of the aging lung in health and disease. Further research was recommended to integrate benchmark biological hallmarks of aging in the lung with the pathobiology of acute and chronic lung diseases with divergent pathologies for which advanced age is the most important risk factor.

Effect of Body Position, Exercise, and Sedation on Estimation of Pulmonary Artery Pressure in Dogs with Degenerative Atrioventricular Valve Disease

Background

Severity of pulmonary hypertension (PH) in dogs is related to clinical signs and prognosis.

Hypothesis/Objectives

We hypothesized that Doppler echocardiographic (DE) indices of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) are influenced by independent factors that create clinically important variability of DE‐based estimates of PH in dogs.

Animals

Thirty‐eight client owned dogs with naturally acquired degenerative atrioventricular valve disease and tricuspid regurgitation (TR).

Methods

Dogs were prospectively enrolled, and target variables were acquired during 4 echocardiographic study periods (lateral recumbency, standing, lateral recumbency after a 6‐minute walk test [6MWT], and lateral recumbency after sedation with butorphanol 0.25 mg/kg IM). Statistical methods included repeated measures ANOVA, mixed model analysis, and Chi‐squared test of association.

Results

There was a significant increase in peak TR flow velocity (TRFV; P < 0.01) after sedation in 78% of dogs, with TRFV increasing by >0.4 m/s in 42% of dogs, independent of stroke volume. A significant effect of study period on DE‐estimated PVR was not found (P = 0.15). There were negligible effects of sonographer, body position, and 6MWT on echocardiographic variables of PH. Clinically relevant cyclic variation of TRFV was found. There was an association between estimation of right atrial pressure based on subjective assessment and estimation based on cranial vena cava collapsibility (P = 0.03).

Conclusions and Clinical Importance

The increase in TRFV observed with sedation could change assessment of PH severity and impact prognostication and interpretation of treatment response. Further studies with invasive validation are needed.

Echocardiographic assessment of the right ventricle in the current era: Application in clinical practice

The right ventricle has unique structural and functional characteristics. It is now well recognized that the so-called forgotten ventricle is a key player in cardiovascular physiology. Furthermore, there is accumulating evidence that demonstrates right ventricular dysfunction as an important marker of morbidity and mortality in several commonly encountered clinical situations such as heart failure, pulmonary hypertension, pulmonary embolism, right ventricular myocardial infarction, and adult congenital heart disease. In contrast to the left ventricle, echocardiographic assessment of right ventricular function is more challenging as volume estimations are not possible without the use of three-dimensional (3D) echocardiography. Guidelines on chamber quantification provide a standardized approach to assessment of the right ventricle. The technique and limitations of each of the parameters for RV size and function need to be fully understood. In this era of multimodality imaging, echocardiography continues to remain a useful tool for the initial assessment and follow-up of patients with right heart pathology. Several novel approaches such as 3D and strain imaging of the right ventricle have expanded the usefulness of this indispensable modality.

Learning a Comorbidity-Driven Taxonomy of Pediatric Pulmonary Hypertension

RATIONALE

Pediatric pulmonary hypertension (PH) is a heterogeneous condition with varying natural history and therapeutic response. Precise classification of PH subtypes is, therefore, crucial for individualizing care. However, gaps remain in our understanding of the spectrum of PH in children.

OBJECTIVE

We seek to study the manifestations of PH in children and to assess the feasibility of applying a network-based approach to discern disease subtypes from comorbidity data recorded in longitudinal data sets.

METHODS AND RESULTS

A retrospective cohort study comprising 6 943 263 children (<18 years of age) enrolled in a commercial health insurance plan in the United States, between January 2010 and May 2013. A total of 1583 (0.02%) children met the criteria for PH. We identified comorbidities significantly associated with PH compared with the general population of children without PH. A Bayesian comorbidity network was constructed to model the interdependencies of these comorbidities, and network-clustering analysis was applied to derive disease subtypes comprising subgraphs of highly connected comorbid conditions. A total of 186 comorbidities were found to be significantly associated with PH. Network analysis of comorbidity patterns captured most of the major PH subtypes with known pathological basis defined by the World Health Organization and Panama classifications. The analysis further identified many subtypes documented in only a few case studies, including rare subtypes associated with several well-described genetic syndromes.

CONCLUSIONS

Application of network science to model comorbidity patterns recorded in longitudinal data sets can facilitate the discovery of disease subtypes. Our analysis relearned established subtypes, thus validating the approach, and identified rare subtypes that are difficult to discern through clinical observations, providing impetus for deeper investigation of the disease subtypes that will enrich current disease classifications.

A natriuretic peptides clearance receptor's agonist reduces pulmonary artery pressures and enhances cardiac performance in preclinical models: New hope for patients with pulmonary hypertension due to left ventricular heart failure

BACKGROUND

In patients with left ventricular heart failure (HF), the development of pulmonary hypertension (PH) is common and represents a strong predictor of death. Despite recent advances in the pathophysiological understanding there is as yet no prospect of cure of this deadly clinical entity and the majority of patients continue to progress to right ventricular failure and die. Furthermore, there is no single medical treatment currently approved for PH related to HF. There is, therefore an urgent unmet need to identify novel pharmacological agents that will prevent the progressive increased or reverse the elevated pulmonary arterial pressures while enhancing cardiac performance in HF.

METHOD AND RESULTS

We here reported, for the first time, using a pressure-loop (P-V) conductance catheter system, that a specific natriuretic peptides clearance receptors' agonist, the ring-deleted atrial natriuretic peptide analogue, cANF4-23 (cANF) reduces pulmonary artery pressures. Strikingly, the administration of the cANF in these mice decreased the RVSP by 50% (n=5, F 25.687, DF 14, p<0.001) and heart rate (HR) by 11% (n=5, F 25.69, DF 14, p<0.001) as well as enhancing cardiac performance including left ventricular contractility in mice. Most strikingly, mice lacking NPR-C were much more susceptible to develop HF, indicating that NPR-C is a critical protective receptor in the heart.

CONCLUSION

Natriuretic peptides clearance receptors' agonists may, therefore represent a novel and attractive therapeutic strategy for PH related to HF, and ultimately improves the life expectancy and quality for millions of people around the planet.

Left atrial dysfunction as a determinant of pulmonary hypertension in patients with severe aortic stenosis and preserved left ventricular ejection fraction

In patients with severe aortic stenosis (AS), the presence of pulmonary hypertension (PH) has been linked to a poor prognosis. We aimed to assess the main determinants of PH in patients with severe AS and preserved left ventricular ejection fraction (LVEF). We prospectively enrolled 108 consecutive patients with isolated severe AS (indexed aortic valve area <0.6 cm²/m²) and LVEF >50%, in sinus rhythm. Left atrial (LA) function was assessed using longitudinal deformation parameters (by speckle tracking echocardiography). PH (defined as systolic pulmonary artery pressure >40 mmHg) was present in 20 patients. Patients with severe AS and PH were older (p = 0.05), had higher BNP values (p = 0.05) and a greater degree of LV diastolic dysfunction: higher E/e' and E/A ratios and lower EDT values (p < 0.03 for all) compared to patients without PH. There were no differences between groups regarding AS severity and LV systolic function parameters. Patients with PH had a more impaired LA function: lower septal and lateral late diastolic peak velocity a' (p < 0.001 and p = 0.04 respectively) and lower LA peak longitudinal strain and strain rate parameters (p ≤ 0.005 for all). In multivariable analysis, LA late diastolic longitudinal strain rate was the only independent correlate of PH in our patients (p = 0.04). Patients with isolated severe AS, preserved LVEF and PH had larger LA volumes, a more impaired LA function, and higher LV filling pressures compared to those without PH. LA booster pump function, reflected by late diastolic longitudinal strain rate, emerged as an independent correlate of PH in these patients.

Maternal nutrient restriction during pregnancy and lactation leads to impaired right ventricular function in young adult baboons

KEY POINTS

Maternal nutrient restriction induces intrauterine growth restriction (IUGR) and leads to heightened cardiovascular risks later in life. We report right ventricular (RV) filling and ejection abnormalities in IUGR young adult baboons using cardiac magnetic resonance imaging. Both functional and morphological indicators of poor RV function were seen, many of which were similar to effects of ageing, but also with a few key differences. We observed more pronounced RV changes compared to our previous report of the left ventricle, suggesting there is likely to be a component of isolated RV abnormality in addition to expected haemodynamic sequelae from left ventricular dysfunction. In particular, our findings raise the suspicion of pulmonary hypertension after IUGR. This study establishes that IUGR also leads to impairment of the right ventricle in addition to the left ventricle classically studied.

ABSTRACT

Maternal nutrient restriction induces intrauterine growth restriction (IUGR), increasing later life chronic disease including cardiovascular dysfunction. Our left ventricular (LV) CMRI studies in IUGR baboons (8 M, 8 F, 5.7 years - human equivalent approximately 25 years), control offspring (8 M, 8 F, 5.6 years), and normal elderly (OLD) baboons (6 M, 6 F, mean 15.9 years) revealed long-term LV abnormalities in IUGR offspring. Although it is known that right ventricular (RV) function is dependent on LV health, the IUGR right ventricle remains poorly studied. We examined the right ventricle with cardiac magnetic resonance imaging in the same cohorts. We observed decreased ejection fraction (49 ± 2 vs. 33 ± 3%, P < 0.001), cardiac index (2.73 ± 0.27 vs. 1.89 ± 0.20 l min-1 m-2 , P < 0.05), early filling rate/body surface area (BSA) (109.2 ± 7.8 vs. 44.6 ± 7.3 ml s-1  m-2 , P < 0.001), wall thickening (61 ± 3 vs. 44 ± 5%, P < 0.05), and longitudinal shortening (26 ± 3 vs. 15 ± 2%, P < 0.01) in IUGR animals with increased chamber volumes. Many, but not all, of these changes share similarities to normal older animals. Our findings suggest IUGR-induced pulmonary hypertension should be further investigated and that atrial volume, pulmonic outflow and interventricular septal motion may provide valuable insights into IUGR cardiovascular physiology. Overall, our findings reaffirm that gestational and neonatal challenges can result in long-term programming of poor offspring cardiovascular health. To our knowledge, this is the first study reporting IUGR-induced programmed adult RV dysfunction in an experimental primate model.

Pulmonary Hypertension in Children With β Thalassemia Major, Are Splenectomy and High-Ferritin Levels Related or Not?

We evaluated the risk of pulmonary hypertension (PH) by measuring the velocity of the tricuspid regurgitation jet velocity (TRV) on echocardiography and the associations among the TRV, ferritin, and history of splenectomy in children with β thalassemia major (TM). In total, 85 children with TM were examined with continuous Doppler flow. Patients with an abnormal TRV (>2.5 m/s) were grouped into those with a TRV of 2.5 to 2.9 m/s and TRV>2.9 m/s. A TRV of >2.5 m/s was identified in 72; 31 (36%) of these patients had a TRV of >2.9 m/s, suggesting a risk for significant PH. The ferritin concentration was significantly higher in patients with a TRV of >2.9 m/s and showed a positive correlation with a TRV. The TRV was significantly correlated with markers of diastolic function: the tricuspid peak early diastolic wave (E) was higher in patients with a TRV of >2.9 m/s and showed a significant correlation with the TRV (R=0.315). The ratio of the TRV over the velocity-time integral (VTI) at the right ventricular outflow tract (TRV/VTI RVOT), which is correlated with the pulmonary vascular resistance, was higher in patients with a TRV of >2.9 m/s. In total, 27 patients had splenectomy. Splenectomized patients had a higher TRV and splenectomy was correlated with the TRV (R=-0.221). A risk of PH as defined by a TRV of >2.9 m/s was common in our patients with TM. Screening with Doppler flow indices on echocardiography can detect PH in early stages.

Echocardiographic Pulmonary Artery Systolic Pressure in the Coronary Artery Risk Development in Young Adults (CARDIA) Study: Associations With Race and Metabolic Dysregulation

Background

The determinants of pulmonary artery systolic pressure (PASP) are not fully understood. It is unknown whether racial differences in PASP exist or if other population characteristics are associated with pulmonary pressure in humans. We examined echocardiographically estimated PASP in the Coronary Artery Risk Development in Young Adults (CARDIA) study, a middle‐aged, biracial community‐based cohort.

Methods and Results

At the CARDIA year‐25 examination, 3469 participants underwent echocardiography, including measurement of tricuspid regurgitant jet velocity to estimate PASP. Clinical features, laboratory values, pulmonary function tests, and measurement of adipose depot volume were analyzed for association with PASP. PASP was estimated in 1311 individuals (61% female, 51% white). Older age, higher blood pressure, and higher body mass index were associated with higher PASP. Black race was associated with higher PASP after adjustment for demographics and left and right ventricular function (β 0.94, 95% CI 0.24‐1.64; P=0.009), but this association was no longer significant after further adjustment for lung volume (β 0.42, 95% CI −0.68 to 0.96; P=0.74). Insulin resistance, inflammation (C‐reactive protein and interleukin‐6), and visceral adipose volume were independently associated with higher PASP after adjustment for relevant covariates. PASP rose with worsening diastolic function (ratio of early transmitral Doppler velocity to average mitral annular tissue Doppler velocity [E/e′] and left atrial volume index).

Conclusions

In a large biracial cohort of middle‐aged adults, we identified associations among black race, insulin resistance, and diastolic dysfunction with higher echocardiographically estimated PASP. Further studies are needed to examine racial differences in PASP and whether insulin resistance directly contributes to pulmonary vascular disease in humans.

Improving on the diagnostic characteristics of echocardiography for pulmonary hypertension

This retrospective study evaluated the diagnostic characteristics of a combination of echocardiographic parameters for pulmonary hypertension (PH). Right ventricular systolic pressure (RVSP) estimation by echocardiography (echo) is used to screen for PH. However, the sensitivity of this method is suboptimal. We hypothesized that RVSP estimation in conjunction with other echo parameters would improve the value of echo for PH. The Duke Echo database was queried for adult patients with known or suspected PH who had undergone both echo and right heart catheterization (RHC) within a 24 h period between 1/1/2008 and 12/31/2013. Patients with complex congenital heart disease, heart transplantation, ventricular assist device, or on mechanical ventilation at time of study were excluded. Diagnostic characteristics of several echo parameters (right atrial enlargement, pulmonary artery (PA) enlargement, RV enlargement, RV dysfunction, and RVSP) for PH (mean PA pressure 25 mmHg on RHC) were evaluated among 1007 patients. RVSP ≥40 had a sensitivity of 77% (accuracy 77), while RVSP ≥35 had the highest sensitivity at 88% (81% accuracy). PA enlargement had the lowest sensitivity at 17%. The area under the curve (AUC) for RVSP was 0.844. A model including RVSP, RA, PA, RV enlargement and RV dysfunction had a higher AUC (AUC = 0.87) than RVSP alone. The value of echo as a screening test for PH is improved by a model incorporating a lower RVSP in addition to other right heart parameters. These findings need to be validated in prospective cohorts.

The prevalence of pulmonary hypertension in patients with obesity hypoventilation syndrome: a prospective observational study

BACKGROUND

One important cardiovascular morbidity that is associated with obesity hypoventilation syndrome (OHS) is the development of pulmonary hypertension (PH). However, few studies have assessed PH in OHS patients. Therefore, we prospectively assessed the prevalence of PH in a large sample of OHS patients.

METHODS

In this prospective observational study, all consecutive OHS patients referred to the sleep disorders clinic during the study period were included. All patients underwent overnight polysomnography (PSG), spirometry, arterial blood samples and thyroid tests. Transthoracic echocardiography was performed for patients who agreed to participate in the study. PH was defined as systolic pulmonary artery pressure (SPAP) >40 mmHg.

RESULTS

Echocardiographic data were available for 77 patients with a mean age of 60.5±11.7 years, a BMI of 43.2±10.4 kg/m², and an Epworth Sleepiness Scale (ESS) score of 11.4±5.5. SPAP was >40 mmHg in 53 patients (68.8%), with a mean SPAP of 64.1±17.1 mmHg. There were no differences between the OHS patients with PH and those with normal PAP in terms of age, BMI, presenting symptoms, comorbidities, arterial blood gasses (ABG), and spirometric and PSG parameters. Approximately 71.4% of women and 61.9% of men with OHS also had PH. SPAP was >40-55 mmHg in 19 (24.7%) patients (18 women), >55-70 mmHg in 15 (19.5%) patients (6 women) and >70 mmHg in 19 (24.7%) patients (16 women). Severe PH (SPAP >70 mmHg) was diagnosed in 28.6% of the women and 14.3% of the men.

CONCLUSIONS

PH is very common among patients with OHS who have been referred to sleep disorders clinics. PH should be considered in the regular clinical assessment of all patients with OHS.

Serum-Free Thyroxine Levels Were Associated with Pulmonary Hypertension and Pulmonary Artery Systolic Pressure in Euthyroid Patients with Coronary Artery Disease

The aim of this study was to evaluate the association between thyroid hormone levels, pulmonary hypertension (PH), and pulmonary artery systolic pressure (PASP) in euthyroid patients with coronary artery disease (CAD). A cross-sectional study was conducted in individuals who underwent coronary angiography and were diagnosed as CAD from March 2013 to November 2013. 811 subjects (185 women and 626 men) were included in this study. PASP was measured by transthoracic Doppler echocardiography. 86 patients were diagnosed as PH and had significantly higher free thyroxine (FT₄) levels than those without PH. Multiple logistic regression analysis demonstrated an independent association of FT₄ levels with PH after adjustment of gender, age, body mass index, systolic blood pressure, left ventricular ejection fraction, hypertension, and medication use of calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists, and nitrates. Serum-free triiodothyronine (FT₃) and thyroid-stimulating hormone (TSH) were not associated with PH. Furthermore, multivariate linear regression analysis showed that FT₄ levels emerged as an independent predictor for PASP, while FT₃ and TSH levels were not associated with PASP. Our study demonstrated that, in euthyroid patients with CAD, FT₄ was an independent risk factor for PH, and FT₄ levels were independently associated with PASP.

Benign Cardiac Effects of Hemoglobin H Disease

BACKGROUND/AIMS

Hemoglobin H (HbH) disease is associated with iron overload, but whether this results in serious cardiac or vascular sequelae is unresolved.

METHODS

We identified 39 adult subjects (age 42 ± 12 years, 13 men) with HbH disease who had undergone echocardiography, 27 of whom had also undergone cardiac and liver magnetic resonance assessment of iron loading using T2*-weighted imaging.

RESULTS

None of the subjects had a history of heart failure or arrhythmias. There were 13/39 subjects with a ferritin level within the sex-based normal range and only 4/39 had ferritin >1,000 ng/ml. Left ventricular (LV) and left atrial dilatation was common, but LV ejection fraction was normal (≥55%) in all subjects. Age was positively correlated with log ferritin in the 27 nontransfused subjects (r = 0.43) and was inversely correlated with the transmitral E wave and E/A ratio (r = -0.69 and r = -0.79, respectively), but no relation of log ferritin with E or E/A was evident. The peak tricuspid regurgitation velocity was normal in 24/29 subjects for whom this was obtained, and it was no more than mildly elevated in the other 5. None of the tested subjects had an abnormal cardiac T2* reading, but half had evidence of liver iron loading.

CONCLUSION

No myocardial iron loading or serious cardiac or vascular sequelae were identified in this cohort with HbH disease.

Time From the Beginning of the Right Ventricle Isovolumetric Contraction to the Peak of the S Wave: A New TDI Indicator for the Non-Invasive Estimation of Pulmonary Hypertension

Background

Echocardiography is a key screening tool in the diagnostic algorithm of pulmonary hypertension (PH). In addition, tissue doppler imaging (TDI) is a promising method for the noninvasive estimation of pulmonary artery pressure (PAP).

Objectives

The aim of this study was to validate the accuracy of measuring the time from the beginning of the right ventricular isovolumetric contraction time (RV IVRT) to the peak of the S wave in the TDI of the base of the RV free wall (time to peak or TTP), as an indicator for the non-invasive estimation of pulmonary hypertension.

Patients and Methods

In this diagnostic test study, 60 consecutive patients referred for right heart catheterization (RHC) were enrolled. A pulse-wave TDI was performed before the cardiac catheterization, with a mean interval of 1 hour between the two measurements. The TDI variables, such as the RV IVRT, myocardial performance index (MPI), and the new “time to peak” parameter, were measured at the lateral basal RV free wall. The patients were divided into two sub-groups according to the RHC findings: no-PH (mean PAP < 25 mmHg) and PH (mean PAP ≥ 25 mmHg) groups. Then, we calculated the specificity and sensitivity of the TDI parameters (including the TTP) for the diagnosis of PH.

Results

In our study, the TTP showed a significant inverse relationship with the PAP. Based on our results, a TTP of less than 127 ms could be used to predict PH, with a sensitivity and specificity of about 70% (AUC = 0.746 ± 0.064).

Conclusions

Based on the results of this study, we suggest the use of a novel “time from the beginning of isovolumetric contraction to the peak of the S wave” (TTP) parameter in the TDI of the base of the RV free wall to predict PH with acceptable accuracy in comparison with RHC.

Congenital coronary artery fistulas complicated with pulmonary hypertension: Analysis of 211 cases

AIM

To compare the behavior of pulmonary hypertension (PHT) associated with coronary artery fistulas (CAFs) between the Asian and Caucasian subjects.

METHODS

CAFs may be complicated with PHT secondary to left-to-right shunt. Literature review limited to the English language. A total of 211 reviewed patients were collected. Of those, 111 were of Asian and 100 were of Caucasian ethnic origin. The mean age of the Asian and the Caucasian groups of patients were 48.9 (range 19-83) and 49.9 years (range 16-85), respectively. In both groups, right heart catheterization was the most commonly (95%) used method for determining pulmonary artery pressure.

RESULTS

From all of the reviewed subjects, PHT was found in 49 patients (23%), of which 15 were Asian and 34 were Caucasian. In 75% of PHT subjects, mild to moderate PHT was reported and 76% of the fistulas had a vascular mode of termination. Treatment was surgical in 61%, followed by percutaneous therapeutic embolization (27%) and finally conservative medical management in 12% of PHT subjects. PHT was associated with a slight female gender predominance. The majority demonstrated mild to moderate PHT. PHT was reported more frequent in the Caucasian compared with the Asian ethnicity group. The majority of fistulas in patients with PHT had a vascular mode of termination. The results of this review are intended to be indicative and require cautious interpretation.

CONCLUSION

The likelihood for a CAF patient to develop PHT is presented when possessing the following features, with a Caucasian female having a fistula with a vascular mode of termination.

Reference ranges and determinants of right ventricle outflow tract acceleration time in healthy adults by two-dimensional echocardiography

The right ventricular outflow tract acceleration time (RVOT-AT) has shown to progressively shorten with increasing degrees of pulmonary pressure. However, the physiologic ranges of RVOT AT are based on small sample sizes and have not been investigated regarding their determining factors. The aim of this study was to investigate reference values and determining factors of RVOT-AT in a large population of healthy subjects and by values described in the literature. In the first part of the study, 1029 healthy subjects (mean age 45.6 ± 16.0 years, 565 (54.7 %) females) were prospectively assessed by clinical examination including demography, vital signs and echocardiography. In the second part, we performed a pooled analysis of eight published studies describing RVOT-AT in healthy subjects (n = 450). Statistical analysis included the calculation of 5 % quantiles for defining reference values. RVOT-AT significantly but weakly correlated with age (r: -0.207; p < 0.001), body mass Index (r: -0.16), systolic (r: -0.158) and diastolic (r: -0.137) blood pressure, heart rate (r: -0.197) and left ventricular (LV) E/A ratio (r: 0.229) (all p < 0.001). No differences were found with regards to sex. In a synopsis of both prospective and literature-based data sets, RVOT-AT weighted means was 138.51 ms and the 5 % quantile was 104.7 ms (95 % confidence interval 98.2-110.1). This study delineates the range of RVOT-AT in healthy adults and it's determining factors. Our study is in line with the cut-off value stated by the European guidelines with an RVOT-AT ≤105 ms denoting abnormal values.

Echocardiographic pulmonary hypertension probability is associated with clinical outcomes after transcatheter aortic valve implantation

AIMS

Pulmonary hypertension (PH) is associated with mortality after transcatheter aortic valve implantation (TAVI). However, diagnosis based on tricuspid regurgitant velocity (TRV) is often inaccurate and unreliable. The updated PH guidelines introduced a PH probability grading implementing additional PH signs on transthoracic echocardiography (TTE), from which we aimed to analyse its effects on clinical outcomes in patients undergoing TAVI.

METHODS AND RESULTS

We included 591 consecutive patients (mean age 80.2±8.4years, 58.0% female, mean STS risk score 6.2±3.8%) undergoing TAVI. Patients were divided into "low" (n=270; TRV ≤2.8m/s without additional PH signs), "intermediate" (n=131; TRV ≤2.8m/s with additional PH signs, or TRV 2.9-3.4m/s without additional PH signs), and "high" PH probability (n=190; TRV 2.9-3.4m/s with additional PH signs, or TRV >3.4m/s). The overall 30-day and 2-year mortality rates were 10.2% and 33.8%, respectively. "High" PH probability was an independent predictor of mortality at 30days (HR 3.68, 95% CI 2.03 to 6.67, p<0.01) and 2years (HR 2.19, 95% CI 1.57 to 3.04, p<0.01), compared to "low" PH probability. The "intermediate" group did not show an increased risk. The presence of additional PH signs resulted in a significantly higher mortality at 30days (19.6% vs. 5.1%, p<0.01) and two years (54.2% vs. 22.5%, p<0.01).

CONCLUSIONS

The updated echocardiographic PH probability model incorporating additional PH signs independently predicts early and late mortality after TAVI. Additional PH signs are of great value in assessing one's risks since its presence is strongly associated with early and late mortality.

Maintaining lung health with longstanding HIV

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV) is now managed as a chronic disease. Non-infectious pulmonary conditions have replaced infection as the biggest threat to lung health, particularly as HIV cohorts age, but there is no consensus on how best to maintain long-term lung health. We review the epidemiology and pathogenesis of chronic obstructive pulmonary disease (COPD), pulmonary arterial hypertension (PAH), and lung cancer in HIV-seropositive individuals.

RECENT FINDINGS

Diagnoses of COPD are now up to 50% more prevalent in HIV-seropositive individuals than HIV-uninfected controls, and prospective pulmonary function studies find significant impairment in 7% to more than 50% of HIV-seropositive individuals. The prevalence of HIV-PAH is 0.2-0.5%, and lung cancer is two to three times more prevalent in HIV-seropositive individuals. Although host factors such as age and smoking have a role, HIV is an independent contributor to the pathogenesis of COPD, PAH, and lung cancer. Chronic inflammation, immune senescence, oxidative stress, and direct effects of viral proteins are all potential pathogenetic mechanisms. Despite their prevalence, non-infectious lung diseases remain underrecognized and evidence for effective screening strategies in HIV-seropositive individuals is limited.

SUMMARY

COPD, PAH, and lung cancer are a growing threat to lung health in the highly active antiretroviral therapy era necessitating early recognition.

Pulmonary artery pressure and arterial oxygen saturation in people living at high or low altitude: systematic review and meta-analysis

More than 140 million people are living at high altitude worldwide. An increase of pulmonary artery pressure (PAP) is a hallmark of high-altitude exposure and, if pronounced, may be associated with important morbidity and mortality. Surprisingly, there is little information on the usual PAP in high-altitude populations. We, therefore, conducted a systematic review (MEDLINE and EMBASE) and meta-analysis of studies published (in English or Spanish) between 2000 and 2015 on echocardiographic estimations of PAP and measurements of arterial oxygen saturation in apparently healthy participants from general populations of high-altitude dwellers (>2,500 m). For comparison, we similarly analyzed data published on these variables during the same period for populations living at low altitude. Twelve high-altitude studies comprising 834 participants and 18 low-altitude studies (710 participants) fulfilled the inclusion criteria. All but one high-altitude studies were performed between 3,600 and 4,350 m. The combined mean systolic PAP (right ventricular-to-right atrial pressure gradient) at high altitude [25.3 mmHg, 95% confidence interval (CI) 24.0, 26.7], as expected was significantly (P < 0.001) higher than at low altitude (18.4 mmHg, 95% CI 17.1,19.7), and arterial oxygen saturation was significantly lower (90.4%, 95% CI 89.3, 91.5) than at low altitude (98.1%; 95% CI 97.7, 98.4). These findings indicate that at an altitude where the very large majority of high-altitude populations are living, pulmonary hypertension appears to be rare. The reference values and distributions for PAP and arterial oxygen saturation in apparently healthy high-altitude dwellers provided by this meta-analysis will be useful to future studies on the adjustments to high altitude in humans.

Comparison of echocardiographic parameters between pre-clinical and clinical advanced diastolic dysfunction patients

BACKGROUND

The diagnosis of heart failure (HF) with preserved ejection fraction requires evidence of grade 2 or 3 (advanced) diastolic dysfunction (ADD), but many patients with ADD do not have clinical HF manifestations, hence termed pre-clinical diastolic dysfunction (PDD). The prevalence and characteristics of PDD in comparison to overt HF disease (clinical-ADD) are still debated.

METHODS

We retrospectively analyzed 373 patients with LVEF≥45% and ADD in our echo-lab database. Exclusion criteria were acute coronary syndromes, ≥moderate valvular disease, cardiomyopathies or pericardial disease. Patients were divided into 2 groups according to the presence/absence of HF symptoms, namely PDD (n=249) and clinical-ADD (n=124). Demographic, clinical and echocardiographic parameters were compared between the groups.

RESULTS

Age, gender and comorbidities were similar between groups, with only a higher body mass index and renal failure significantly more prevalent in the clinical-ADD patients. Neither LV mass nor the ADD severity was related to the presence of symptoms; lateral mitral E/E' and pulmonary artery systolic pressure were significantly higher in clinical-ADD patients (14±5 vs. 12±4, p<0.05 and 40±13 vs. 36±11mmHg, p<0.05, respectively) and were the only parameters to correlate with the presence of symptoms of clinical-ADD in multivariable logistic regression (odds ratio=1.07 (CI 1.02-1.1, p=0.008) and 1.03 (CI 1.01-1.05, p=0.01), respectively).

CONCLUSIONS

In patients referred for an echocardiogram at a community cardiology center, PDD was twice as common as clinical-ADD. Hemodynamic parameters reflecting elevated filling and pulmonary pressures, rather than traditional comorbidities and/or classical structural abnormalities, were the only parameters related to the presence of HF symptoms.

Non-invasive monitoring of pulmonary artery pressure at the bedside

Current solutions for the monitoring of pulmonary artery pressure (PAP) in patients suffering from pulmonary hypertension are limited to invasive means. Non-invasive alternatives, such as Doppler echocardiography, are incompatible with continuous monitoring due to their dependency on qualified personnel to perform the measurements. In the present study, a novel non-invasive and unsupervised approach based on the use of electrical impedance tomography (EIT) is presented. The approach was evaluated in three healthy subjects undergoing hypoxia-induced variations in PAP. A timing parameter - physiologically linked to the PAP via the so-called pulse wave velocity principle - was automatically extracted from the EIT data. Reference systolic PAP estimates were obtained by echocardiography. Strong correlation scores (r e [0.844, 0.990]) were found between the EIT-derived parameter and the reference PAP, thereby suggesting the validity of the proposed approach. If confirmed in larger datasets, these findings could open the way for a new branch of fully non-invasive hemodynamic monitors for patients with pulmonary hypertension.

Pulmonary arterial hypertension associated to connective tissue diseases

Pulmonary arterial hypertension is a well-known complication of connective tissue diseases such as systemic sclerosis, systemic lupus erythematosus, mixed connective tissue diseases, and to a lesser extent, rheumatoid arthritis, dermatopolymyositis and primary Sjögren’s syndrome. In these patients, pulmonary hypertension may occur in association with left heart disease, interstitial fibrosis or as a result of a isolated pulmonary arteriopathy. The incidence of pulmonary arterial hypertension in the limited form of systemic sclerosis is about 10%. The pathophysiologic mechanisms leading to pulmonary arterial hypertension remain unknown. Symptoms and clinical presentation are very similar to idiopathic pulmonary arterial hypertension but mortality was confirmed to be higher. Echocardiography is the reference investigation for the detection of pulmonary arterial hypertension but the results should be confirmed by right heart catheterization. Treatment appears more complex as compared to idiopathic pulmonary arterial hypertension. Intravenous epoprostenol therapy has been shown to be effective in a special trail. Also, the endothelin receptor antagonists bosentan and sitaxentan, the phosphodyesterase-type-5 sildenafil and subcutaneous treprostinil have shown favourable results.

Impact of age on pulmonary artery systolic pressures at rest and with exercise

AIM

It is not well known if advancing age influences normal rest or exercise pulmonary artery pressures. The purpose of the study was to evaluate the association of increasing age with measurements of pulmonary artery systolic pressure at rest and with exercise.

SUBJECTS AND METHODS

A total of 467 adults without cardiopulmonary disease and normal exercise capacity (age range: 18-85 years) underwent symptom-limited treadmill exercise testing with Doppler measurement of rest and exercise pulmonary artery systolic pressure.

RESULTS

There was a progressive increase in rest and exercise pulmonary artery pressures with increasing age. Pulmonary artery systolic pressures at rest and with exercise were 25±5mmHg and 33±9mmHg, respectively, in those <40 years, and 30±5mmHg and 41±12mmHg, respectively, in those ≥70 years. While elevated left-sided cardiac filling pressures were excluded by protocol design, markers of arterial stiffness associated with the age-dependent effects on pulmonary pressures.

CONCLUSION

These data demonstrate that in echocardiographically normal adults, pulmonary artery systolic pressure increases with advancing age. This increase is seen at rest and with exercise. These increases in pulmonary pressure occur in association with decreasing transpulmonary flow and increases in systemic pulse pressure, suggesting that age-associated blood vessel stiffening may contribute to these differences in pulmonary artery systolic pressure.

Mean pulmonary arterial pressures in Angus steers increase from cow-calf to feedlot-finishing phases

Pulmonary arterial hypertension due to hypoxia-induced pulmonary vascular remodeling is the predominant cause of right-sided congestive heart failure (CHF) in cattle. Historically, heart failure was problematic only at altitudes over 2,134 m. However, anecdotal reports suggest that the incidence of heart failure is increasing in feedlot cattle at moderate altitude (800 to 1,600 m), with late-fed, or fat, cattle at greatest risk. The goal of this study was to evaluate pulmonary arterial pressures (PAP) in a cohort of male Angus calves from suckling to finishing to better understand why heart failure is particularly problematic in fat cattle. It was hypothesized that mean PAP would increase through the feeding period and that the calves with the greatest pressures at high altitude would have the greatest pressures as fat cattle. A total of 362 PAP measurements were obtained from 153 calves. Calves were tested at altitudes of 2,170 (4 and 6 mo old), 1,560 (13 mo old), and 1,300 m (13 and 18 mo old). Mean PAP were greater in 18-mo-old steers than any other age group (mean = 50.3 mm Hg; 95% confidence interval 48.2 to 52.4; < 0.05). Calves that had the greatest mean pressure at 6 mo of age tended to have the greatest mean pressures at 18 mo of age ( = 0.45, < 0.001). The increase in mean PAP with increasing age and adiposity likely predisposed the steers to an increased risk of CHF during the finishing phase.

Efficacy and safety of regenerative cell therapy for pulmonary arterial hypertension in animal models: a preclinical systematic review protocol

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare disease (15 cases per million) that is characterized by widespread loss of the pulmonary microcirculation and elevated pulmonary vascular resistance leading to pathological right ventricular remodeling and ultimately right heart failure. Regenerative cell therapies (i.e., therapies involving cells with stem or progenitor-like properties) could potentially restore the effective lung microcirculation and provide a curative therapy for PAH. Preclinical evidence suggests that regenerative cell therapy using endothelial progenitor cells or mesenchymal stem cells may be beneficial in the treatment of PAH. These findings have led to the completion of a small number of human clinical trials, albeit with modest effect compared to animal studies. The objective of this systematic review is to compare the efficacy and safety of regenerative cell therapies in preclinical models of PAH as well as assess study quality to inform future clinical studies.

METHODS

We will include preclinical studies of PAH in which a regenerative cell type was administered and outcomes compared to a disease control. The primary outcome will be pulmonary hemodynamics as assessed by measurement of right ventricular systolic pressure and/or mean pulmonary arterial pressure. Secondary outcomes will include mortality, survival, right ventricular remodeling, pulmonary vascular resistance, cardiac output, cardiac index, pulmonary acceleration time, tricuspid annular systolic excursion, and right ventricular wall thickness. Electronic searches of MEDLINE and EMBASE databases will be constructed and reviewed by the Peer Review of Electronic Search Strategies (PRESS) process. Search results will be screened independently in duplicate. Data from eligible studies will be extracted, pooled, and analyzed using random effects models. Risk of bias will be assessed using the SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk of bias tool, and individual study reporting will be assessed according to an itemized checklist based on the Animal Research: Reporting of In vivo Experiments (ARRIVE) guidelines.

DISCUSSION

This systematic review will examine the efficacy and safety of regenerative cell therapy in preclinical models of PAH. As well, the literature will be assessed for study quality and risk of bias. The results will guide the design of future clinical trials and preclinical animal studies.

SYSTEMATIC REVIEW REGISTRATION

CAMARADES ( http://www.dcn.ed.ac.uk/camarades/SyRF/Protocols.htm ).

The Pulmonary Hypertension Consult: Clinical and Coding Considerations

Pulmonary hypertension (PH) is an increasingly recognized cause of morbidity and mortality, and in the past 20 years, there has been a rapid expansion in research and available therapies. Although it is defined quite simply as a mean pulmonary arterial pressure of ≥ 25 mm Hg, PH encompasses a heterogeneous group of disease processes. In the past, PH was classified as primary or secondary, but as understanding of the various contributing diseases has increased, classification systems have attempted to group these diseases by clinical features and disease mechanism. The evaluation of patients with suspected PH can be cumbersome, and a careful and methodical approach is needed to ensure timely and accurate diagnosis, correct physiological classification, and appropriate treatment. In this review, we discuss the classification and diagnostic evaluation of PH in adults as well as some of the billing and coding considerations involved in this evaluation.

The Evolving Landscape of Exercise-Induced Pulmonary Hypertension

OPINION STATEMENT

Normal pulmonary artery pressures at rest, with an exaggerated rise during exercise, characterize exercise-induced pulmonary hypertension. Exercise itself as it relates to this condition is not deleterious, nor does it cause or induce disease. However much like any classical stress test, it is a physiologic probe that aids in disease unmasking. Although more work is required to establish criteria for defining this clinical entity, the phenomenon is real. It remains unknown whether it represents a nascent form of cardiopulmonary disease and whether its genesis predicts fulminant cardiopulmonary disease. Incremental cardiopulmonary exercise testing and the construction of pressure-flow plots to describe the pulmonary vascular response to exercise will be essential in defining this disease. The critical first step remains a consensus definition that will allow for further prospective study focused by a common language.

Pulmonary hypertension: prevalence and risk factors

Introduction

Pulmonary arterial hypertension (PAH), defined as a systolic pulmonary artery pressure above 35 mm Hg, is another vascular disease entity recently described in patients receiving hemodialysis. It is a major problem due to its high prevalence and morbidity and mortality. Its pathophysiological mechanism is just known and the strategies for its supported not yet defined.

Aims

To determine the prevalence of PAH in our hemodialysis patients and its risk factors.

Methodology

Single center descriptive and analytical cross-sectional study, including 111 hemodialysis patients who had benefit from a trans-thoracic cardiac Doppler ultrasound during 2014. A value greater than or equal to 35 mm Hg is considered PAH and classified as follows: mild PAH (35 50 mm Hg), moderate PAH (50 70 mm Hg), and severe pulmonary hypertension (> 70 mm Hg). Patients with a high probability of secondary PAH, especially those with the following history: chronic obstructive pulmonary disease, pulmonary embolism, were not included.

Results

The mean age was 44.3 ± 14.2 years. Among the 111 patients, 18 had pulmonary arterial pressure above 35 mm Hg corresponding to 16.22% of PAH prevalence. The average pressure was 45 mm Hg. Of these 18 patients, 11.8% had mild PAH, 3.4% moderate PAH and 0.8% severe PAH. The average hemodialysis duration was significantly associated with PAH (p = 0.003); as well as valvular calcification (p = 0.000), mitral regurgitation (p = 0.001) and tricuspid regurgitation (p = 0.002).

Conclusion

Primary pulmonary hypertension is a major problem among our hemodialysis because of its high prevalence and its risk factors.

Clinical iron deficiency disturbs normal human responses to hypoxia

BACKGROUND

Iron bioavailability has been identified as a factor that influences cellular hypoxia sensing, putatively via an action on the hypoxia-inducible factor (HIF) pathway. We therefore hypothesized that clinical iron deficiency would disturb integrated human responses to hypoxia.

METHODS

We performed a prospective, controlled, observational study of the effects of iron status on hypoxic pulmonary hypertension. Individuals with absolute iron deficiency (ID) and an iron-replete (IR) control group were exposed to two 6-hour periods of isocapnic hypoxia. The second hypoxic exposure was preceded by i.v. infusion of iron. Pulmonary artery systolic pressure (PASP) was serially assessed with Doppler echocardiography.

RESULTS

Thirteen ID individuals completed the study and were age- and sex-matched with controls. PASP did not differ by group or study day before each hypoxic exposure. During the first 6-hour hypoxic exposure, the rise in PASP was 6.2 mmHg greater in the ID group (absolute rises 16.1 and 10.7 mmHg, respectively; 95% CI for difference, 2.7-9.7 mmHg, P = 0.001). Intravenous iron attenuated the PASP rise in both groups; however, the effect was greater in ID participants than in controls (absolute reductions 11.1 and 6.8 mmHg, respectively; 95% CI for difference in change, -8.3 to -0.3 mmHg, P = 0.035). Serum erythropoietin responses to hypoxia also differed between groups.

CONCLUSION

Clinical iron deficiency disturbs normal responses to hypoxia, as evidenced by exaggerated hypoxic pulmonary hypertension that is reversed by subsequent iron administration. Disturbed hypoxia sensing and signaling provides a mechanism through which iron deficiency may be detrimental to human health.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01847352).

FUNDING

M.C. Frise is the recipient of a British Heart Foundation Clinical Research Training Fellowship (FS/14/48/30828). K.L. Dorrington is supported by the Dunhill Medical Trust (R178/1110). D.J. Roberts was supported by R&D funding from National Health Service (NHS) Blood and Transplant and a National Institute for Health Research (NIHR) Programme grant (RP-PG-0310-1004). This research was funded by the NIHR Oxford Biomedical Research Centre Programme.

Echocardiographic Reference Values for Right Atrial Size in Children with and without Atrial Septal Defects or Pulmonary Hypertension

Right atrial (RA) size may become a very useful, easily obtainable, echocardiographic variable in patients with congenital heart disease (CHD) with right-heart dysfunction; however, according studies in children are lacking. We investigated growth-related changes of RA dimensions in healthy children. Moreover, we determined the predictive value of RA variables in both children with secundum atrial septal defect (ASD) and children with pulmonary hypertension (PH) secondary to CHD (PH-CHD). This is a prospective study in 516 healthy children, in 80 children with a secundum ASD (>7 mm superior-inferior dimension), and in 42 children with PH-CHD. We determined three RA variables, i.e., end-systolic major-axis length, end-systolic minor-axis length, and end-systolic area, stratified by age, body weight, length, and surface area. RA end-systolic length and area z scores were increased in children with ASD and PH-CHD when compared to those variables in the healthy control population. Using the Youden Index to determine the best cutoff scores in sex- and age-specific RA dimensions, we observed a sensitivity and specificity up to 94 and 91 %, respectively, in ASD children and 98 and 94 %, respectively, in PH-CHD children. We provide normal values (z scores -2 to +2) for RA size and area in a representative, large pediatric cohort. Enlarged RA variables with scores >+2 were predictive of secundum ASD and PH-CHD. Two-dimensional determination of RA size can identify enlarged RAs in the setting of high volume load (ASD) or pressure load (PH-CHD).

Association of Right Ventricular Pressure and Volume Overload with Non-Ischemic Septal Fibrosis on Cardiac Magnetic Resonance

BACKGROUND

Non-ischemic fibrosis (NIF) on cardiac magnetic resonance (CMR) has been linked to poor prognosis, but its association with adverse right ventricular (RV) remodeling is unknown. This study examined a broad cohort of patients with RV dysfunction, so as to identify relationships between NIF and RV remodeling indices, including RV pressure load, volume and wall stress.

METHODS AND RESULTS

The population comprised patients with RV dysfunction (EF<50%) undergoing CMR and transthoracic echo within a 14 day (5 ± 3) interval. Cardiac structure, function, and NIF were assessed on CMR. Pulmonary artery systolic pressure (PASP) was measured on echo. 118 patients with RV dysfunction were studied, among whom 47% had NIF. Patients with NIF had lower RVEF (34 ± 10 vs. 39 ± 9%; p = 0.01) but similar LVEF (40 ± 21 vs. 39 ± 18%; p = 0.7) and LV volumes (p = NS). RV wall stress was higher with NIF (17 ± 7 vs. 12 ± 6 kPa; p < 0.001) corresponding to increased RV end-systolic volume (143 ± 79 vs. 110 ± 36 ml; p = 0.006), myocardial mass (60 ± 21 vs. 53 ± 17 gm; p = 0.04), and PASP (52 ± 18 vs. 41 ± 18 mmHg; p = 0.001). NIF was associated with increased wall stress among subgroups with isolated RV (p = 0.005) and both RV and LV dysfunction (p = 0.003). In multivariable analysis, NIF was independently associated with RV volume (OR = 1.17 per 10 ml, [CI 1.04-1.32]; p = 0.01) and PASP (OR = 1.43 per 10 mmHg, [1.14-1.81]; p = 0.002) but not RV mass (OR = 0.91 per 10 gm, [0.69-1.20]; p = 0.5) [model χ2 = 21; p<0.001]. NIF prevalence was higher in relation to PA pressure and RV dilation and was > 6-fold more common in the highest, vs. the lowest, common tertile of PASP and RV size (p<0.001).

CONCLUSION

Among wall stress components, NIF was independently associated with RV chamber dilation and afterload, supporting the concept that NIF is linked to adverse RV chamber remodeling.

Pathophysiology and treatment of pulmonary hypertension in sickle cell disease

Pulmonary hypertension affects ∼10% of adult patients with sickle cell disease (SCD), particularly those with the homozygous genotype. An increase in pulmonary artery systolic pressure, estimated noninvasively by echocardiography, helps identify SCD patients at risk for pulmonary hypertension, but definitive diagnosis requires right-heart catheterization. About half of SCD-related pulmonary hypertension patients have precapillary pulmonary hypertension with potential etiologies of (1) a nitric oxide deficiency state and vasculopathy consequent to intravascular hemolysis, (2) chronic pulmonary thromboembolism, or (3) upregulated hypoxic responses secondary to anemia, low O2 saturation, and microvascular obstruction. The remainder have postcapillary pulmonary hypertension secondary to left ventricular dysfunction. Although the pulmonary artery pressure in SCD patients with pulmonary hypertension is only moderately elevated, they have a markedly higher risk of death than patients without pulmonary hypertension. Guidelines for diagnosis and management of SCD-related pulmonary hypertension were published recently by the American Thoracic Society. Management of adults with sickle-related pulmonary hypertension is based on anticoagulation for those with thromboembolism; oxygen therapy for those with low oxygen saturation; treatment of left ventricular failure in those with postcapillary pulmonary hypertension; and hydroxyurea or transfusions to raise the hemoglobin concentration, reduce hemolysis, and prevent vaso-occlusive events that cause additional increases in pulmonary pressure. Randomized trials have not identified drugs to lower pulmonary pressure in SCD patients with precapillary pulmonary hypertension. Patients with hemodynamics of pulmonary arterial hypertension should be referred to specialized centers and considered for treatments known to be effective in other forms of pulmonary arterial hypertension. There have been reports that some of these treatments improve SCD-related pulmonary hypertension.

Percutaneous CT guided lung biopsy in patients with pulmonary hypertension: Assessment of complications

PURPOSE

To assess the complications of CT-guided percutaneous transthoracic needle aspiration and/or core biopsy (PTNAB) of lung nodules in patients with pulmonary arterial hypertension (PHTN).

METHOD AND MATERIALS

We analyzed PTNAB of 74 lung lesions (mean size: 3.6 ± 2.1 cm) in 74 patients (M: F 38:36; age 68 ± 15 years) with documented PHTN on cardiac ultrasound. 39 patients with lung lesions (M: F 24:15; age 65 ± 14) who underwent PTNAB in the same period with right ventricle systolic pressure (RVSP) <35 mm Hg were selected as controls. Pulmonary arterial pressures were estimated on cardiac ultrasounds by using the tricuspid regurgitation jet method. Two thoracic radiologists reviewed the medical records and PTNAB images on a PACS station and documented nodule size, location, distance traversed in lung, technical success and complications.

RESULTS

Fine needle aspirates were obtained in all and core biopsy in 23% (17/74) of the nodules. 61% (45/74) of the nodules were in the middle and 39% (29/74) were in the outer third of lung. PHTN was mild, moderate and severe in 84% (62/74), 13% (10/74) and 3% (2/74) of the patients. Biopsy was complicated by hemorrhage in 26% (19/74), moderate hemoptysis in 1.3% (1/74), pneumothorax in 17% (12/74), chest tube in 1.3% (1/74) and hemothorax in 1.3% (1/74) of the patients. The complications rate in control group was similar, hemorrhage in 33% (19/39) (p=0.6), moderate hemoptysis in 5% (2/39) (p=0.3), pneumothorax in 28% (11/39) (p=0.2), chest tube in (0/39) (p=0.3), and hemothorax in 3% (1/39) of the patients (p=0.7).

CONCLUSION

Percutaneous needle biopsy of lung lesions in patients with mild to moderate PHTN can be performed without significant increase in complications.

The potential role and limitations of echocardiography in acute respiratory distress syndrome

Bedside use of Doppler echocardiography is being featured as a promising, clinically useful tool in assessing the pulmonary circulation in patients with acute respiratory distress syndrome (ARDS). The present review is aimed at summarizing the available evidence obtained with echocardiography on right ventricle (RV) function and pulmonary circulation in ARDS and to highlight the potential of this technique in clinical practice (only articles in English language were considered). According to the available evidence on echocardiographic findings, the following conclusions can be drawn: (a) echocardiography (transthoracic and transesophageal) has a growing role in the management ARDS patients mainly because of the strict interactions between the lung (and ventilation) and the RV and pulmonary circulation; (b) there may be a continuum of alterations in RV size and function and pulmonary circulation which may end in the development of acute cor pulmonale, probably paralleling ARDS disease severity; and (c) the detection of acute cor pulmonale should prompt intensivists to tailor their ventilatory strategy to the individual patient depending on the echocardiography findings. Bearing in mind the clinical role and growing importance of echocardiography in ARDS and the available evidence on this topic, we present a flow chart including the parameters to be measured and the timing of echo exams in ARDS patients. Despite the important progress that echocardiography has gained in the evaluation of patients with ARDS, several open questions remain and echocardiography still appears to be underused in these patients. A more systematic use of echocardiography (mainly through shared protocols) in ARDS could help intensivists to tailor the optimal treatment in individual patients as well as highlighting the limits and potential of this methodology in patients with ALI.