Association of anemia and long-term survival in patients with pulmonary hypertension. Int J Cardiol. 2011;150:291-295. [PMID: 20472313 DOI: 10.1016/j.ijcard.2010.04.038]

Prognostic value of pulmonary diffusing capacity for carbon monoxide and ventilation-perfusion SPECT findings in pulmonary arterial hypertension

Reduced pulmonary diffusing capacity for carbon monoxide (DLCO) can be observed in pulmonary arterial hypertension (PAH) and associates with increased mortality. However, the prognostic value of DLCO when corrected for haemoglobin (DLCOc), an independent modifier of DLCO, remains understudied. Additionally, the prognostic role of ventilation (V)-perfusion (Q) emission computed tomography (V/Q SPECT) findings in patients with PAH, which may concurrently be performed to rule out chronic thromboembolic pulmonary hypertension, is uncertain. A retrospective cohort study was conducted on 152 patients with PAH referred to a tertiary hospital for evaluation from January 2011 to January 2020. Lung function tests, clinical data and V/Q SPECT were ascertained. Cox regression analysis was performed to evaluate the association between DLCOc, DLCO and V/Q SPECT defects at referral with all-cause mortality. In equally adjusted Cox regression analysis, each percentage increase in DLCOc % predicted (%pred) (hazard ratio (HR) 0.97; 95% CI: 0.94-0.99) and DLCO%pred (HR 0.97; 95% CI: 0.94-0.99) was similarly associated with all-cause mortality. There was no detectable difference in area under the curve for prediction of all-cause mortality by DLCOc%pred and DLCO%pred (C-index 0.71 and 0.72, respectively, P = 0.85 for difference). None of the defects noted on V/Q SPECT were significantly associated with mortality, but mismatched defects were associated with lower values of DLCOc%pred and DLCO%pred. DLCOc%pred and DLCO%pred perform equally as prognostic markers in PAH, supporting the use of either metric when available for prognostic stratification.

Retrospective cohort study of pulmonary arterial hypertension associated with connective tissue disease effect on patients' prognosis

OBJECTIVE

The objectives of this study are to clarify clinical characteristics and recognize prognostic factors of CTD-PAH patients.

METHODS

A retrospective cohort study of consecutive patients with documented CTD-PAH diagnosis from Jan 2014 to Dec 2019 was conducted, the ones who have other comorbid conditions that cause PH were excluded. Survival functions were plotted using the Kaplan-Meier method. Univariable and multivariable Cox regression analysis was applied to determine the survival-related factors.

RESULTS

In 144 patients with CTD-PAH analyzed, the median sPAP value was 52.5 (44.0, 71.0) mmHg, the overall targeted drug usage rate was 55.6%, and only 27.5% patients were given combination. Twenty-four non-PAH-CTD patients with sPAP value were included as the control group. Compared with non-PAH-CTD groups, CTD-PAH patients had worse cardiac function, higher NT-pro BNP and γ-globulin level, and lower PaCO2 level. Compared with the mild PAH group, the moderate-severe PAH group had worse cardiac function; increased Hb, HCT, and NP-pro BNP level; and decreased PaO2. Kaplan-Meier analysis showed significant difference for survival among non-PAH-CTD, mild CTD-PAH, and moderate-severe CTD-PAH groups. The univariate analyses showed that Hb, pH, and Ln (NT-pro BNP) were identified as factors significantly associated with survival, and Hb and pH showed significant association with risk of death in the multivariate model. Kaplan-Meier analysis also showed that Hb > 109.0 g/L and pH > 7.457 affected CTD-PAH patients' survival significantly.

CONCLUSIONS

PAH is not rare in CTDs patients; PAH affects CTD patients' prognosis significantly. Higher Hb and pH were associated with an increased risk of death. Key Points • Pulmonary arterial hypertension affects connective tissue disease patients' prognosis significantly. • The significantly factors associated with survival is hemoglobin, pH, and Ln (NT-pro BNP).

Investigation of red blood cell and platelet indices in adult dogs suffered from myxomatous mitral valve disease with and without pulmonary hypertension

Background

Pulmonary hypertension (PH) is a common complication of cardiopulmonary disease. In dogs, PH commonly occurs secondary to myxomatous mitral valve disease (MMVD). Red blood cell and platelet indices including mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), mean platelet volume (MPV) and platelet distribution width (PDW), have previously been found to be indicators for predicting and prognosing PH in humans. Therefore, this study aimed to investigate whether these indices are associated with MMVD and/or PH in dogs.

Methods

Two hundred and forty-six dogs were retrospectively recruited for the study and classified into 4 groups: normal (n = 49), MMVD (n =102), PH (n =17), MMVD+PH (n =78). A sub-analysis was performed in dogs with MMVD without evidence of PH according to stage B1 (n =20), stage B2 (n =15), stage C (n =67). The data are expressed as median (interquartile range).

Results and discussion

No significant differences (p < 0.05) were found in MCV, RDW and MPV among all groups (normal, MMVD, PH and MMVD+PH). However, decreases in MCH and MCHC were found in MMVD [22.40 (20.90-23.50) pg and 35.25 (33.08-36.90) g/dL], MMVD+PH [22.25 (20.85-23.98) pg and 35.65 (33.30-37.33) g/dL] and PH groups [21.20 (20.60-22.20) pg and 33.80 (32.75-35.70) g/dL] compared to the normal dogs [24.29 (23.55-24.90) pg and 38.20 (37.50-39.05) g/dL] (p < 0.001). Decreases in PDW were found in dogs in the MMVD+PH [15.10 (14.98-15.30) %] groups compared to dogs in the normal group [15.30 (15.10-15.50) %] (p = 0.004). Sub-analysis of MMVD dogs without PH showed a decrease in MCH in dogs with stage B2 MMVD [21.00 (20.50-22.90) pg] and stage C MMVD [22.40 (20.90-23.20) pg] compared to normal dogs [24.29 (23.55-24.90) pg] (p < 0.001). MCHC of dogs with stage B1 [36.55 (33.53-37.78) g/dL] (p = 0.004), B2 [32.90 (32.00-35.00) g/dL] (p < 0.001) and C MMVD [35.30 (33.30-36.80) g/dL] (p < 0.001) were lower than those of normal dogs [38.20 (37.50-39.05) g/dL]. PDW in the stage C MMVD group [15.10 (15.00-15.30) %] was reduced compared to the normal group [15.30 (15.10-15.50) %] (p  = 0.042) and the stage B1 MMVD group [15.35 (15.23-15.68) %] (p = 0.002). MCH, MCHC and PDW were negatively correlated with the left atrial and left ventricular size.

Conclusion

Decreases in MCH and MCHC are related to MMVD, precapillary PH and postcapillary PH while PDW are associated with MMVD severity but not with the presence of PH.

Characteristics, Long-term Survival, and Risk Assessment of Pediatric Pulmonary Arterial Hypertension in China: Insights From a National Multicenter Prospective Registry

BACKGROUND

Registry-based studies of pediatric pulmonary arterial hypertension (PPAH) are scarce in developing countries, including China. The PPAH risk assessment tool needs further evaluation and improvement.

RESEARCH QUESTION

What are the characteristics and long-term survival of PPAH in China and what is the performance of the PPAH risk model in Chinese patients?

STUDY DESIGN AND METHODS

Patients with PAH were enrolled in the national prospective multicenter registry from August 2009 through December 2019. Children 3 months to 18 years of age at the time of PAH diagnosis were analyzed.

RESULTS

A total of 247 children with PAH were enrolled. The median patient age was 14.8 years, and 58.3% of patients were female. Most patients had a diagnosis of PAH associated with congenital heart disease (CHD; 61.5%) and idiopathic or heritable PAH (37.7%). The median time from symptom onset to PAH diagnosis was 24 months. The mean pulmonary artery pressure and pulmonary vascular resistance index were 70.78 ± 19.80 mm Hg and 21.82 ± 11.18 Wood Units·m2, respectively. Patients with CHD-associated PAH experienced a longer diagnostic delay and demonstrated higher pulmonary artery pressure, but better cardiac performance, than those with idiopathic or heritable PAH. An increased number of patients received targeted therapy at the last follow-up compared with baseline. The 5- and 10-year survival rates of the entire cohort were 74.9% and 55.7%, respectively, with better survival in patients with CHD-associated PAH than in those with idiopathic or heritable PAH. Patients with low risk had better survival than those with high risk according to the simplified noninvasive risk score model with weight, function class, and echocardiographic right ventricular size, both at baseline and follow-up.

INTERPRETATION

Patients with PPAH in China showed severely compromised hemodynamics with marked diagnostic delay. The long-term survival of PPAH is poor despite the increased usefulness of targeted drugs. The simplified noninvasive risk model demonstrated good performance for predicting survival in Chinese children with PAH.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01417338; URL: www.

CLINICALTRIALS

gov.

Chronic Thromboembolic Pulmonary Hypertension in Females: Clinical Features and Survival

Sparse data are available on the female-specific features of chronic thromboembolic pulmonary hypertension (CTEPH). We prospectively enrolled 160 consecutive female patients who were firstly diagnosed with CTEPH between 2013 and 2019 to explore their clinical phenotypes, treatment patterns, and long-term survival. The patients’ mean age was 54.7 ± 13.8 years, 70.6% provided a confirmed history of venous thromboembolism, 46 (28.8%) patients underwent pulmonary endarterectomy (PEA), 65 (40.6%) received balloon pulmonary angioplasty (BPA), and 49 (30.6%) were treated with medical therapy alone. The patients were followed for a median of 51 (34–70) months; three patients were lost to follow-up, and twenty-two patients died. The estimated survival rates at 1, 3, 5, and 7 years were 98.1% (95% CI 96.0–100), 96.9% (95% CI 94.2–99.6), 85.1% (95% CI 78.1–92.2), and 76.2% (95% CI 65.2–87.2), respectively. After adjusting for the confounders, the results of the multivariate Cox analysis showed that the presence of anemia (5.56, 95% CI 1.6–19.22) was associated with an increased risk of all-cause death, and compared with medical treatment, receiving PEA and BPA decreased the risk of death by 74% (0.26, 95% CI 0.07–0.97) and 86% (0.14, 95% CI 0.04–0.57), respectively. In conclusion, in the modern era of CTEPH treatment, invasive revascularization combined with targeted therapy display good clinical outcomes for females; anemia should be actively modified, which may lead to clinical improvements. (ClinicalTrials.gov Identifier: NCT05360992).

Development and Validation of a Nomogram for Predicting the Long-Term Survival in Patients With Chronic Thromboembolic Pulmonary Hypertension

There remains a lack of prognosis models for patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study aims to develop a nomogram predicting 3-, 5-, and 7-year survival in patients with CTEPH and verify the prognostic model. Patients with CTEPH diagnosed in Fuwai Hospital were enrolled consecutively between May 2013 and May 2019. Among them, 70% were randomly split into a training set and the other 30% as a validation set for external validation. Cox proportional hazards model was used to identify the potential survival-related factors which were candidate variables for the establishment of nomogram and the final model was internally validated by the bootstrap method. A total of 350 patients were included in the final analysis and the median follow-up period of the whole cohort was 51.2 months. Multivariate analysis of Cox proportional hazards regression showed body mass index, mean right atrial pressure, N-terminal pro-brain natriuretic peptide (per 500 ng/ml increase in concentration), presence of anemia, and main treatment choice were the independent risk factors of mortality. The nomogram demonstrated good discrimination with the corrected C-index of 0.82 in the training set, and the C-index of 0.80 (95% CI: 0.70 to 0.91) in the external validation set. The calibration plots also showed a good agreement between predicted and actual survival in both training and validation sets. In conclusion, we developed an easy-to-use nomogram with good apparent performance using 5 readily available variables, which may help physicians to identify CTEPH patients at high risk for poor prognosis and implement medical interventions.

Noninvasive Risk Score to Screen for Pulmonary Hypertension With Elevated Pulmonary Vascular Resistance in Diseases of Chronic Volume Overload

Volume overload promotes pulmonary hypertension (PH) through pulmonary venous hypertension. However, PH with elevated pulmonary vascular resistance (hereafter PH-PVR) may develop in patients with diseases of volume overload, such as heart failure or chronic kidney disease (CKD). In such cases, volume management alone may be insufficient to slow PH progression. An accurate, noninvasive method to screen for PH-PVR in these diseases would facilitate early targeted therapy. We integrated invasive hemodynamic and echocardiography data collected from a single-center clinical cohort and identified patients with CKD or heart failure at the time of assessment. We applied penalized regression to derive a risk score of clinical parameters and echocardiography data associated with PH-PVR and categorized patients into low- (≤5 points), intermediate- (6-10 points), or high-risk (>10 points) groups. Using an internal validation strategy, we evaluated the ability of this risk score to predict PH-PVR and determined the association of this risk classification with 3-year all-cause mortality. Of 2422 patients, 42.4% had PH-PVR. In adjusted analyses, tricuspid regurgitant velocity, right ventricular function, BMI, heart rate, and hemoglobin most strongly associated with PH-PVR. The risk score significantly associated with PH-PVR (age-adjusted odds ratio 11.69 for the highest-risk group, 95% confidence interval [CI] 6.54-20.92). The high-risk group also associated with a significantly higher risk of 3-year all-cause mortality in adjusted analyses (hazard ratio 1.85, 95% CI 1.50-2.27). In conclusion, a noninvasive risk score derived from echocardiography and clinical parameters significantly associated with PH-PVR and all-cause mortality in a cohort of patients with CKD and heart failure.

Novel Experimental Therapies for Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive and devastating disease characterized by pulmonary artery vasoconstriction and vascular remodeling leading to vascular rarefaction with elevation of pulmonary arterial pressures and pulmonary vascular resistance. Often PAH will cause death from right heart failure. Current PAH-targeted therapies improve functional capacity, pulmonary hemodynamics and reduce hospitalization. Nevertheless, today PAH still remains incurable and is often refractory to medical therapy, underscoring the need for further research. Over the last three decades, PAH has evolved from a disease of unknown pathogenesis devoid of effective therapy to a condition whose cellular, genetic and molecular underpinnings are unfolding. This article provides an update on current knowledge and summarizes the progression in recent advances in pharmacological therapy in PAH.

Association Between Hemoglobin and Major Adverse Cardiac Events: A Secondary Analysis from a Retrospective Cohort Study

BACKGROUND

This study aims to investigate the association between hemoglobin and major adverse cardiac events (MACE) in patients with stable coronary artery disease (CAD) who were treated with percutaneous coronary intervention (PCI).

METHODS

This was a secondary analysis based on a retrospective cohort study involving 204 patients with stable CAD. Patients were divided into four groups according to hemoglobin levels (Q1: 6.90-12.30 g/dL; Q2: 12.40-13.80 g/dL; Q3: 13.90-14.90 g/dL; Q4: 15.00-19.00 g/dL). Lasso regression analysis was performed to select characteristic variables and reduce dimensions. Odds ratio (OR) and 95% confidence interval (CI) were used for comparing data among groups.

RESULTS

After an average follow-up of 783 days, 28/204 (17.72%) patients with CAD occurred MACE. Univariate analysis data showed that hemoglobin level was negatively associated with the incidence of MACE in patients with CAD treated with PCI (Q2 vs Q1: OR=0.19, P=0.005; Q3 vs Q1: OR=0.25, P=0.013; Q4 vs Q1: OR=0.13, P=0.002). The negative correlation between hemoglobin and MACE still existed after adjusting selected variables obtained from multivariate regression analysis (Q2 vs Q1: OR= 0.18, P=0.007; Q3 vs Q1: OR=0.29, P=0.038; Q4 vs Q1: OR=0.19, P=0.016). Curve fitting illustrated that hemoglobin level presented a non-linear and negative association with MACE in patients with CAD treated with PCI.

CONCLUSIONS

Hemoglobin level can be utilized as a prognostic indicator of MACE in patients with CAD after PCI.

The effect of myxomatous mitral valve disease severity on packed cell volume in dogs

OBJECTIVES

The aim of this study was to examine whether associations between disease severity and packed cell volume exist in dogs with myxomatous mitral valve disease.

MATERIALS AND METHODS

Data were selected from 289 dogs that had been examined at a research clinic (2004-2017) on multiple occasions (n=1465). American College of Veterinary Internal Medicine stage and echocardiographic measurements were entered in separate multivariable linear mixed effects models with packed cell volume as the dependent variable. Age, breed, sex, weight and blood urea nitrogen concentrations were additionally tested in these analyses to control for patient characteristics.

RESULTS

Packed cell volume (% whole blood) in stages B1 and B2 (B1: 42.62 ±0.27, P=0.001; B2: 41.77± 0.42, P < 0.001) was lower than stage A (44.57 ±0.53). In stage C, packed cell volume was greater than both preclinical stages (C: 43.84 ±0.46). When the administration of loop diuretics was included in statistical models, packed cell volume was inversely related to normalised left ventricular internal diameters (β: -2.37; 95% confidence intervals: -3.49, -1.25; P < 0.001).

CLINICAL SIGNIFICANCE

Dogs with myxomatous mitral valve disease may develop reductions in packed cell volume as their disease progresses. Although this finding was statistically significant at a population level, it should be noted that the differences described are relatively small. This, along with other causes of variation in packed cell volume, means that changes would be challenging to appreciate within individual patients. Plasma volume depletion following diuretic administration may explain why findings differed in stage C.

Risk factors for 30-day readmission in adults hospitalized for pulmonary hypertension

Readmissions for pulmonary hypertension are poorly understood and understudied. We sought to determine national estimates and risk factors for 30-day readmission after pulmonary hypertension-related hospitalizations. We utilized the Healthcare Cost and Utilization Project Nationwide Readmission Database, which has weighted estimates of roughly 35 million discharges in the US. Adult patients with primary International Classification of Disease, Ninth Revision, Clinical Modification diagnosis codes of 416.0 and 416.8 for primary and secondary pulmonary hypertension with an index admission between 2012 and 2014 and any readmission within 30 days of the index event were identified. Predictors of 30-day readmission were identified using multivariable logistic regression with adjustment for covariates. Results showed that the national estimate for Primary Pulmonary Hypertension vs Secondary Pulmonary Hypertension-related index events between 2012 and 2014 with 30-day readmission was 247 vs 2550 corresponding to a national readmission risk estimate of 17% vs 18.3%, respectively. The presence of fluid and electrolyte disorders, renal failure, and alcohol abuse were associated with increased risk of readmission in Primary Pulmonary Hypertension, while factors associated with Secondary Pulmonary Hypertension readmissions included anemia, congestive heart failure, lung disease, fluid and electrolyte disorders, renal failure, diabetes, and liver disease. The median cost of Primary Pulmonary Hypertension admissions and readmissions were $46,132 (IQR: $25,384–$85,647) and $41,604.50 (IQR: $22,481.50–$84,420.50), respectively. The median costs of Secondary Pulmonary Hypertension admissions and readmissions were $34,893 (IQR: $19,670–$66,143) and $36,279 (IQR: $19,059–$74,679), respectively. In conclusion, approximately 19% of Primary Pulmonary Hypertension and Secondary Pulmonary Hypertension hospitalizations result in 30-day readmission, with significant costs accrued during the index hospitalization and readmission. With evolving clinical terminology and diagnostic codes, future study will need to better clarify underlying factors associated with readmissions amongst pulmonary hypertension sub-types, and identify methods and procedures to minimize readmission risk.

Red blood cell folate and cardiovascular deaths among hypertensive adults, an 18-year follow-up of a national cohort

A shift towards high folate concentration has emerged following folate fortification. However, the association between folate and health outcomes beyond neural tube defects remains inconclusive. To assess the relationship between red blood cell (RBC) folate and the risk of cardiovascular death among hypertensive patients, we analyzed the data of 2,986 adults aged 19 or older with hypertension who participated in the National Health and Nutrition Examination Survey (1991-1994) as the baseline examination and were followed up through December 31, 2010. After 32,743 person-years of follow-up with an average of 11.7 (standard error = 0.03) years, 1192 deaths were recorded with 579 cardiovascular deaths. The median survival time was significantly shorter in adults in the high folate quartile than in patients in the low folate quartile: 11.97 vs. 13.85 years for heart diseases and 13.37 vs. 14.82 years for myocardial infarction deaths. The cardiovascular mortality was 13.04, 16.95, and 26.61/1,000 person-years for the groups with low, intermediate and high folate quartiles, respectively. After adjustment for age, sex and other factors, a J-shaped association emerged. The hazard ratios (HRs) of all cardiovascular deaths in patients with low, intermediate, and high folate quartiles were 1.09 (0.94, 1.27), 1.00 (reference), and 1.44 (1.31, 1.58), respectively. The corresponding HRs of acute myocardial infarction were 1.13 (0.86, 1.50), 1.00, and 2.13 (1.77, 2.57), respectively. The estimates remained significant after adjustment for BMI and medication use. Compared to moderate RBC folate levels, high folate levels were significantly associated with an increased risk of cardiovascular deaths, especially acute myocardial infarction.

Geriatric Nutritional Risk Index Is Associated With Prognosis in Patients With Pulmonary Arterial Hypertension and Chronic Thromboembolic Pulmonary Hypertension

Background: The Geriatric Nutritional Risk Index (GNRI) is a simple tool for assessing nutritional risk that predicts prognosis in patients with heart failure. This study evaluated associations between the GNRI at first hospitalization and prognosis in patients with pulmonary artery hypertension (PAH) and those with chronic thromboembolic pulmonary hypertension (CTEPH). Methods and Results: This retrospective investigation included 104 patients with either PAH or CTEPH who were treated at Kagoshima University Hospital in Japan. Patients were divided into a high (≥92) and low (<92) GNRI groups. Body mass index and serum albumin levels were significantly lower in the low GNRI group (P<0.001). Over a median follow-up period of 24 months, the incidence of pulmonary hypertension rehospitalization was higher in the low GNRI group (P=0.04). Kaplan-Meier analysis revealed that the cumulative event-free rate was significantly lower in the low GNRI group (P=0.002). Low GNRI was significantly associated with a poorer outcome after adjusting for different sets of confounding factors, including: age and sex (P=0.004); age, sex, and PAH (P=0.043); and age, sex, and mean pulmonary artery pressure (P=0.003). Conclusions: The GNRI at first hospitalization is useful for predicting prognosis in PAH and CTEPH patients.

Biventricular diastolic dysfunction, thrombocytopenia, and red blood cell macrocytosis in experimental pulmonary arterial hypertension

Pulmonary arterial hypertension is a fatal disease, where death is associated with right heart failure and reduced cardiorespiratory reserve. The Sugen 5416, hypoxia and normoxia Fischer rat model mimics human pulmonary arterial hypertension, although the cause(s) of death remains incompletely understood. Here, we hypothesized that these animals develop biventricular diastolic dysfunction that contributes to tissue hypoperfusion coincident with severe pulmonary arterial hypertension. We performed comprehensive echocardiographic and hematologic assessments. Serial echocardiogram at 3-5 weeks was performed followed by blood sampling via aortic or cardiac puncture. Echocardiogram revealed pulmonary arterial hypertension in pulmonary artery Doppler waves, including notched wave envelopes, and decreased pulmonary artery acceleration time/pulmonary artery ejection time ratio and right ventricular outflow tract velocity time integral. Impaired right ventricular systolic function, assessed by decreased tricuspid annular plane systolic excursion and tricuspid tissue Doppler systolic positive wave velocity, was observed in pulmonary arterial hypertension. Tricuspid and mitral pulsed wave and tissue Doppler findings suggested biventricular diastolic dysfunction, with dynamic changes in early and late diastolic filling waves, their fusion patterns, and a decrease in e' velocity. Heart rate and ejection fraction did not change, but cardiac output, stroke volume, and end-diastolic volume were decreased, and inferior vena cava respiratory variation was decreased. Blood electrolyte values were suggestive of intravascular volume expansion early in the disease followed by volume contraction and tissue hypoperfusion in the latter stages of disease. Complete blood count showed thrombocytopenia and non-anemic macrocytosis with reticulocytosis and an increase in red blood cell distribution width. Thus, pulmonary, cardiac, and hematological findings in Fischer animals with pulmonary arterial hypertension are characteristic of humans and provide an insightful experimental platform to resolve mechanisms of disease progression.

Impact of Nutrition on Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterized by sustained vasoconstriction, vascular remodeling, inflammation, and in situ thrombosis. Although there have been important advances in the knowledge of the pathophysiology of PAH, it remains a debilitating, limiting, and rapidly progressive disease. Vitamin D and iron deficiency are worldwide health problems of pandemic proportions. Notably, these nutritional alterations are largely more prevalent in PAH patients than in the general population and there are several pieces of evidence suggesting that they may trigger or aggravate disease progression. There are also several case reports associating scurvy, due to severe vitamin C deficiency, with PAH. Flavonoids such as quercetin, isoflavonoids such as genistein, and other dietary polyphenols including resveratrol slow the progression of the disease in animal models of PAH. Finally, the role of the gut microbiota and its interplay with the diet, host immune system, and energy metabolism is emerging in multiple cardiovascular diseases. The alteration of the gut microbiota has also been reported in animal models of PAH. It is thus possible that in the near future interventions targeting the nutritional status and the gut dysbiosis will improve the outcome of these patients.

Anaemia and iron dysregulation: untapped therapeutic targets in chronic lung disease?

Hypoxia is common in many chronic lung diseases. Beyond pulmonary considerations, delivery of oxygen (O2) to the tissues and subsequent O2 utilisation is also determined by other factors including red blood cell mass and iron status; consequently, disruption to these mechanisms provides further physiological strains on an already stressed system. O2 availability influences ventilation, regulates pulmonary blood flow and impacts gene expression throughout the body. Deleterious effects of poor tissue oxygenation include decreased exercise tolerance, increased cardiac strain and pulmonary hypertension in addition to pathophysiological involvement of multiple other organs resulting in progressive frailty. Increasing inspired O2 is expensive, disliked by patients and does not normalise tissue oxygenation; thus, other strategies that improve O2 delivery and utilisation may provide novel therapeutic opportunities in patients with lung disease. In this review, we focus on the rationale and possibilities for doing this by increasing haemoglobin availability or improving iron regulation.

Recommendations on RBC Transfusion in Infants and Children With Acquired and Congenital Heart Disease From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for RBC transfusions in critically ill children with acquired and congenital heart disease developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of 38 international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

Experts developed evidence-based and, when evidence was lacking, expert-based clinical recommendations and research priorities for RBC transfusions in critically ill children. The cardiac disease subgroup included three experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA appropriateness method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Twenty-one recommendations were developed and reached agreement. For children with myocardial dysfunction and/or pulmonary hypertension, there is no evidence that transfusion greater than hemoglobin of 10 g/dL is beneficial. For children with uncorrected heart disease, we recommended maintaining hemoglobin greater than 7-9.0 g/dL depending upon their cardiopulmonary reserve. For stable children undergoing biventricular repairs, we recommend not transfusing if the hemoglobin is greater than 7.0 g/dL. For infants undergoing staged palliative procedures with stable hemodynamics, we recommend avoiding transfusions solely based upon hemoglobin, if hemoglobin is greater than 9.0 g/dL. We recommend intraoperative and postoperative blood conservation measures. There are insufficient data supporting shorter storage duration RBCs. The risks and benefits of RBC transfusions in children with cardiac disease requires further study.

CONCLUSIONS

We present RBC transfusion management recommendations for the critically ill child with cardiac disease. Clinical recommendations emphasize relevant hemoglobin thresholds, and research recommendations emphasize need for further understanding of physiologic and hemoglobin thresholds and alternatives to RBC transfusion in subpopulations lacking pediatric literature.

The crucial impact of iron deficiency definition for the course of precapillary pulmonary hypertension

Imbalances of iron homeostasis are associated with an adverse clinical outcome of pulmonary hypertension (PH). Herein, we aimed to analyze the impact of iron deficiency (ID) in a real-life PH patient cohort according to different currently used ID definitions. In a retrospective study including 153 precapillary PH patients followed over a mean period of five years, iron deficiency was assessed according to five clinical definitions used in previous trials. The impact of ID on clinical, hematological and hemodynamic parameters was investigated. Depending on the different cutoff levels for serum ferritin and transferrin saturation, currently used ID definitions indicated a prevalence of either true or functional ID in 11 to 75 percent of PH patients. A good diagnostic accuracy was achieved by using the sTFRF/log ferritin (sTFRF) index, which identified 33 to 42 percent of PH patients as being iron deficient. The sTFRF index had the best prediction for the association between ID and clinical outcome. Iron deficient patients with precapillary PH had a significantly higher mortality as compared to non-iron deficiency subjects, which was true for both, PH patients with and without anemia. Although levels of the iron hormone hepcidin were rather affected by ID than by inflammation, they were not associated with the clinical course or mortality of PH subjects. To conclude, ID had a significant impact on the clinical course of precapillary PH patients. The appropriate use of robust biomarkers to define ID is a prerequisite to further evaluate the role of ID and the potential benefit of iron supplementation in precapillary PH patients.

Pathobiology of pulmonary arterial hypertension: understanding the roads less travelled

The pathobiology of pulmonary arterial hypertension (PAH) is complex and incompletely understood. Although three pathogenic pathways have been relatively well characterised, it is widely accepted that dysfunction in a multitude of other cellular processes is likely to play a critical role in driving the development of PAH. Currently available therapies, which all target one of the three well-characterised pathways, provide significant benefits for patients; however, PAH remains a progressive and ultimately fatal disease. The development of drugs to target alternative pathogenic pathways is, therefore, an attractive proposition and one that may complement existing treatment regimens to improve outcomes for patients. Considerable research has been undertaken to identify the role of the less well-understood pathways and in this review we will highlight some of the key discoveries and the potential for utility as therapeutic targets.

Hemodynamic response to treatment of iron deficiency anemia in pulmonary arterial hypertension: longitudinal insights from an implantable hemodynamic monitor

Despite new therapeutic options, pulmonary arterial hypertension (PAH) remains a progressive disease associated with substantial morbidity and mortality. As such, additional strategies for monitoring and adjunctive management of this disease are important. A 59-year-old woman with scleroderma-associated PAH received an implantable hemodynamic monitor (IHM) as part of a research protocol at our institution. Pulmonary artery pressures, heart rate, and cardiac output (sensor-based algorithm) were measured on a daily basis, and parameters of right ventricular (RV) performance and afterload were calculated. At the time of IHM implant, the patient had functional class III symptoms, was receiving triple-drug therapy, and had normal hemoglobin levels. Four months after implant, and with further optimization of prostacyclin therapy, she had improvement in her symptoms. However, shortly thereafter, while the patient was receiving stable drug therapy, her case regressed with worsening symptoms, and the patient received a new diagnosis of iron deficiency anemia. Oral iron supplementation resulted in normalization of hemoglobin levels and improvement in the patient's iron profile. A gradual and sustained reduction in pulmonary pressures was noted after initiation of oral iron accompanied by increased RV performance and favorable reduction in RV afterload. The patient had significant symptomatic improvement. Iron deficiency is an underappreciated yet easily treatable risk factor in PAH. Use of IHM in this case longitudinally illustrates the optimization of pulmonary hemodynamics and RV afterload in tandem with clinical improvement achieved by a simple therapy.

Hematological disorders and pulmonary hypertension

Pulmonary hypertension (PH), a serious disorder with a high morbidity and mortality rate, is known to occur in a number of unrelated systemic diseases. Several hematological disorders such as sickle cell disease, thalassemia and myeloproliferative diseases develop PH which worsens the prognosis. Associated oxidant injury and vascular inflammation cause endothelial damage and dysfunction. Pulmonary vascular endothelial damage/dysfunction is an early event in PH resulting in the loss of vascular reactivity, activation of proliferative and antiapoptotic pathways leading to vascular remodeling, elevated pulmonary artery pressure, right ventricular hypertrophy and premature death. Hemolysis observed in hematological disorders leads to free hemoglobin which rapidly scavenges nitric oxide (NO), limiting its bioavailability, and leading to endothelial dysfunction. In addition, hemolysis releases arginase into the circulation which converts L-arginine to ornithine, thus bypassing NO production. Furthermore, treatments for hematological disorders such as immunosuppressive therapy, splenectomy, bone marrow transplantation, and radiation have been shown to contribute to the development of PH. Recent studies have shown deregulated iron homeostasis in patients with cardiopulmonary diseases including pulmonary arterial hypertension (PAH). Several studies have reported low iron levels in patients with idiopathic PAH, and iron deficiency is an important risk factor. This article reviews PH associated with hematological disorders and its mechanism; and iron homeostasis and its relevance to PH.

Future perspectives in pulmonary arterial hypertension

While there have been advances in the field of pulmonary arterial hypertension (PAH), disease management remains suboptimal for many patients. The development of novel treatments and strategies can provide opportunities to target other mechanisms that play a role in the complex pathobiology of PAH outside of the three main pathophysiological pathways. In this review, we highlight some of the potential PAH therapies or techniques that are being, or have been, investigated in phase II clinical trials. This review also discusses potential points for consideration in the development of novel therapies that target putative disease mediators or modifiers.

Novel therapies and well-designed trials are important for improving the management of PAH patientshttp://ow.ly/YHPY304XdvH

Association of Anemic Hypoxia and Increased Pulmonary Artery Systolic Pressure in Patients With Systemic Lupus Erythematosus

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a rare but serious complication of systemic lupus erythematosus (SLE). Chronic hypoxia is known to cause PAH resulting from pulmonary vascular remodeling. We investigated the association between anemic hypoxia and PAH in SLE patients.

METHODS

Systolic pulmonary artery pressure (PAP) was measured in 132 SLE patients by echocardiography. Increased PAP was defined as resting PAP > 40 mm Hg. Oxygen delivery (DO2) was estimated as the product of cardiac output and arterial oxygen content.

RESULTS

Of 132 patients, 17 (12.9%) had increased PAP, and these patients had significantly lower DO2 values than patients with normal PAP (P = 0.002). The DO2 values inversely correlated with PAP values (γ = -0.308, P < 0.001) and plasma N-terminal pro-brain natriuretic peptide levels (γ = -0.323, P = 0.001), but positively correlated with hemoglobin levels (γ = 0.402, P < 0.001). Compared to those with normal PAP, patients with increased PAP had significantly longer durations of anemia over the preceding 6-24 months. Patients with anemia of longer durations (≥3 months) in the preceding 6 months had a higher risk of increased PAP compared to those with shorter durations (P < 0.001). When SLE patients were divided into 3 groups according to hemoglobin and PAP, serum interleukin-6 (IL-6) levels increased across groups with higher PAP (P = 0.001 for trend), but decreased across tertiles of hemoglobin levels (P = 0.008 for trend).

CONCLUSION

Our data indicate an association between chronic anemic hypoxia and increased PAP in SLE patients and suggest that increased IL-6 might participate in this process.

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.

Intravenous iron therapy in patients with idiopathic pulmonary arterial hypertension and iron deficiency

In patients with idiopathic pulmonary arterial hypertension (iPAH), iron deficiency is common and has been associated with reduced exercise capacity and worse survival. Previous studies have shown beneficial effects of intravenous iron administration. In this study, we investigated the use of intravenous iron therapy in iron-deficient iPAH patients in terms of safety and effects on exercise capacity, and we studied whether altered exercise capacity resulted from changes in right ventricular (RV) function and skeletal muscle oxygen handling. Fifteen patients with iPAH and iron deficiency were included. Patients underwent a 6-minute walk test, cardiopulmonary exercise tests, cardiac magnetic resonance imaging, and a quadriceps muscle biopsy and completed a quality-of-life questionnaire before and 12 weeks after receiving a high dose of intravenous iron. The primary end point, 6-minute walk distance, was not significantly changed after 12 weeks (409 ± 110 m before vs. 428 ± 94 m after; P = 0.07). Secondary end points showed that intravenous iron administration was well tolerated and increased body iron stores in all patients. In addition, exercise endurance time (P < 0.001) and aerobic capacity (P < 0.001) increased significantly after iron therapy. This coincided with improved oxygen handling in quadriceps muscle cells, although cardiac function at rest and maximal [Formula: see text] were unchanged. Furthermore, iron treatment was associated with improved quality of life (P < 0.05). In conclusion, intravenous iron therapy in iron-deficient iPAH patients improves exercise endurance capacity. This could not be explained by improved RV function; however, increased quadriceps muscle oxygen handling may play a role. (

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01288651).

The crossroads of iron with hypoxia and cellular metabolism. Implications in the pathobiology of pulmonary hypertension

The pathologic hallmark of pulmonary arterial hypertension (PAH) is pulmonary vascular remodeling, characterized by endothelial cell proliferation, smooth muscle hypertrophy, and perivascular inflammation, ultimately contributing to increased pulmonary arterial pressures. Several recent studies have observed that iron deficiency in patients with various forms of PAH is associated with worsened clinical outcome. Iron plays a key role in many cellular processes regulating the response to hypoxia, oxidative stress, cellular proliferation, and cell metabolism. Given the potential importance of iron supplementation in patients with the disease and the broad cellular functions of iron, we review its role in processes that pertain to PAH.

Coenzyme Q supplementation in pulmonary arterial hypertension

Mitochondrial dysfunction is a fundamental abnormality in the vascular endothelium and smooth muscle of patients with pulmonary arterial hypertension (PAH). Because coenzyme Q (CoQ) is essential for mitochondrial function and efficient oxygen utilization as the electron carrier in the inner mitochondrial membrane, we hypothesized that CoQ would improve mitochondrial function and benefit PAH patients. To test this, oxidized and reduced levels of CoQ, cardiac function by echocardiogram, mitochondrial functions of heme synthesis and cellular metabolism were evaluated in PAH patients (N=8) in comparison to healthy controls (N=7), at baseline and after 12 weeks oral CoQ supplementation. CoQ levels were similar among PAH and control individuals, and increased in all subjects with CoQ supplementation. PAH patients had higher CoQ levels than controls with supplementation, and a tendency to a higher reduced-to-oxidized CoQ ratio. Cardiac parameters improved with CoQ supplementation, although 6-minute walk distances and BNP levels did not significantly change. Consistent with improved mitochondrial synthetic function, hemoglobin increased and red cell distribution width (RDW) decreased in PAH patients with CoQ, while hemoglobin declined slightly and RDW did not change in healthy controls. In contrast, metabolic and redox parameters, including lactate, pyruvate and reduced or oxidized gluthathione, did not change in PAH patients with CoQ. In summary, CoQ improved hemoglobin and red cell maturation in PAH, but longer studies and/or higher doses with a randomized placebo-controlled controlled design are necessary to evaluate the clinical benefit of this simple nutritional supplement.

High levels of zinc-protoporphyrin identify iron metabolic abnormalities in pulmonary arterial hypertension

Iron homeostasis influences the development of pulmonary arterial hypertension (PAH) associated with hypoxia or hematologic disorders. To investigate whether severity of idiopathic PAH (IPAH) is impacted by alterations in iron metabolism, we assessed iron metabolic markers, including levels of zinc-protoporphyrin (Zn-pp), transferrin receptor, and red blood cell numbers and morphology in IPAH, associated PAH and sleep apnea-induced pulmonary hypertension patients in comparison to healthy controls and asthmatics. Despite similarly normal measures of iron metabolism, Zn-pp levels in IPAH and sleep apnea patients were elevated approximately twofold, indicating deficient iron incorporation to form heme and levels were closely related to measures of disease severity. Consistent with high Zn-pp, PAH patients had increased red cell distribution width (RDW). In an expanded cohort including patients with IPAH and familial disease, the RDW was validated and related to clinical parameters of severity; including pulmonary artery pressures and 6-minute walk distances. These results reveal an increased prevalence of subclinical functional iron deficiency in primary forms of PAH that is quantitatively related to disease severity. This suggests that altered iron homeostasis influences disease progression and demonstrates the importance of closely monitoring iron status in PAH patients.

Hypoxia-inducible factors in human pulmonary arterial hypertension: a link to the intrinsic myeloid abnormalities

Pulmonary arterial hypertension (PAH) is a proliferative vasculopathy characterized by high circulating CD34(+)CD133(+) proangiogenic progenitors, and endothelial cells that have pathologic expression of hypoxia-inducible factor 1 α (HIF-1α). Here, CD34(+)CD133(+) progenitor cell numbers are shown to be higher in PAH bone marrow, blood, and pulmonary arteries than in healthy controls. The HIF-inducible myeloid-activating factors erythropoietin, stem cell factor (SCF), and hepatocyte growth factor (HGF) are also present at higher than normal levels in PAH blood, and related to disease severity. Primary endothelial cells harvested from human PAH lungs produce greater HGF and progenitor recruitment factor stromal-derived factor 1 α (SDF-1α) than control lung endothelial cells, and thus may contribute to bone marrow activation. Even though PAH patients had normal numbers of circulating blood elements, hematopoietic alterations in myeloid and erythroid lineages and reticulin fibrosis identified a subclinical myeloproliferative process. Unexpectedly, evaluation of bone marrow progenitors and reticulin in nonaffected family members of patients with familial PAH revealed similar myeloid abnormalities. Altogether, the results show that PAH is linked to myeloid abnormalities, some of which may be related to increased production of HIF-inducible factors by diseased pulmonary vasculature, but findings in nonaffected family suggest myeloid abnormalities may be intrinsic to the disease process.