Relation of noninvasive parameters and pulmonary artery mean pressure in patients with chronic obstructive lung disease

A series of 31 patients with various degrees of chronic obstructive pulmonary disease (COPD) underwent radionuclide ventriculography with right heart catheterization. The patients were divided into 2 groups on the basis of their reduction in forced expiratory volume in 1 s (FEV1). In patients with FEV1 greater than or equal to 1,300 ml (group 1) the oxygen partial pressure (PaO2) did not significantly change with exercise, while in patients with FEV1 less than or equal to 1,200 ml (group 2) the PaO2 significantly decreased (p less than 0.05) with exercise. The groups were significantly different from each other as to the correlation between hemodynamic and noninvasive parameters. In the resting state, the correlation between pulmonary artery mean pressure (PAP) and both residual volume to total lung capacity (RV/TLC) and PaO2 was close only in group 2. By contrast, the right ventricular end diastolic wall thickness (RWD) correlated closely with PAP in both groups. With exercise close correlations were observed between PAP and the noninvasive parameters: RWD, PaO2 and right ventricular ejection fraction in both groups. Arterial CO2 partial pressure (PaCO2) was only increased (greater than or equal to 45 mm Hg) in group 2. This parameter correlated moderately closely with PAP both in the resting and the exercise state only in group 2. The predictive value of PaCO2 greater than or equal to 45 mm Hg for estimation of PAP greater than 35 mm Hg during exercise was 100%. We conclude that separation of patients with COPD into groups with different impairments of the lung function parameter FEV1 can improve the correlation coefficients between noninvasive and invasive parameters. The exercise values obviously correlate more closely than the resting values. An increased value of echocardiographically determined RWD seems to be a reliable parameter for prediction of PAP.     

Zymosan activated plasma infusion in sheep: Effects of ethanol administration

Zymosan activated plasma infusion induces pulmonary sequestration of neutrophils and the release of TXA₂ into the pulmonary vascular bed causing profound and transient pulmonary hypertension.Since ethanol (ETOH) inhibits several inflammatory functions of neutrophils, including adherence and aggregation, we examined the ability of anesthetic doses of ETOH to alter the hemodynamic and cellular response to the infusion of zymosan activated plasma (ZAP) in vivo. Twenty five ml of autologous ZAP was intravenously infused into five control and seven (ETOH-treated sheep during mechanical ventillation. In control sheep the mean pulmonary artery pressure (PAP) transiently increased from 14.7±1.4 mm Hg (mean±SEM) to a pead of 38+8 mm Hg by three minutes after beginning the infusion of ZAP. Blood leukocyte concentration transiently decreased 19% below the baseline value due to pulmonary sequestration of polymorphonuclear leukocytes (PMN). Plasma TXB₂ levels measured by radioimmunoassay (RIA) increased from 0.2 to 5.4 ng/ml six minutes after the initiation of ZAP infusion.In five sheep, intravenous infusion of 200 ml of 96% ETOH yielded very high plasma concentrations (882±101 mg%) and completely inhibited both the rise of PAP and the increase of plasma TXB₂ levels after ZAP infusion. However, blood leukocytes transiently decreased 58% below the baseline value. Lower plasma levels of ETOH (200 and 400 mg%) did not prevent either the increase of PAP or the elevation of plasma TXB₂ after ZAP infusion.     

Lack of additional action of oxygen on pulmonary artery pressure at the peak of verapamil or captopril action in pulmonary hypertension secondary to mitral stenosis]

The aim of the study was to investigate whether oxygen causes a further decrease in pulmonary artery pressure after administration of calcium channel blocker-verapamil-or angiotensin converting enzyme inhibitor-captopril-in the secondary pulmonary hypertension. We studied 37 patients with the secondary pulmonary hypertension (mean pulmonary artery systolic pressure = 56.1 mm Hg) due to mitral stenosis. After having completed hemodynamic diagnostic procedures, basal oxygen test was performed and pulmonary artery pressure was recorded at 10 min of oxygen breathing. Then, 10 mg of verapamil was injected into the pulmonary artery of 16 patients and 21 patients received 75 mg of oral captopril. At the peak of vasodilation, 30 min after verapamil and 90 min after captopril administration, pulmonary artery pressure was recorded and oxygen test was repeated. Baseline oxygen test produced a statistically significant decrease in pulmonary artery pressure. Verapamil and captopril also lowered pulmonary artery systolic and diastolic pressures. The second oxygen test did not cause a further decrease in the pulmonary artery pressure; mean pulmonary artery systolic pressure was 52.3 +/- 23.7 mm Hg, pulmonary artery diastolic pressure 22.7 +/- 10.6 mm Hg before and 49.1 +/- 23.8 mm Hg and 23.0 +/- 13.5 mm Hg, respectively after the test in verapamil group, and 47.0 +/- 15.5 mm Hg and 21.7 +/- 8.4 mm Hg before and 46.6 +/- 15.4 mm Hg, respectively in captopril subset. The results may support the thesis that vasodilating effect depends rather on the degree of pulmonary vascular changes than on the vasodilatory mechanism of particular drugs.     

Borderline pulmonary pressures in scleroderma - a ‘pre-pulmonary arterial hypertension’ condition?

Patients with systemic sclerosis may develop borderline pulmonary arterial pressure. The clinical relevance of this condition is not always clear. Reported data support the evidence that this subgroup may represent an intermediate stage between normal pulmonary arterial pressure and manifest pulmonary arterial hypertension, a serious complication in scleroderma. Recognizing the clinical relevance of borderline pulmonary arterial pressure increase in scleroderma patients, future studies should aim for clear evidence for diagnostic and therapeutic algorithms for this population.In their recent study, Visovatti and colleagues [1] present a detailed analysis of patients with borderline pulmonary arterial pressure (PAP) as a subgroup analysis of the DETECT study, providing important clinical data for understanding early pulmonary vasculopathy in patients with systemic sclerosis.In fact, every physician who has observed the dramatic deterioration of patients with pulmonary arterial hypertension (PAH) and successive right ventricular failure would urge for the earlier recognition and therapy of this devastating condition. About 10% of all scleroderma patients may develop PAH [2], which - besides lung fibrosis - represents the most frequent cause of death in this patient population [3]. But can PAH be recognized at an early stage and maybe even prevented?If we assume that the increase of PAP is a process lasting for a longer period of time, there must be a phase of transition from normal (mean PAP ≤20 mmHg) pulmonary hemodynamic conditions to PAH (mean PAP ≥25 mmHg). Patients in this so-called ''borderline'' range may represent the early stage of PAH. Earlier studies found that such patients were more likely to develop pulmonary hypertension than patients with mean PAP ≤20 mmHg, with a hazard ratio of 3.7 [4]. The rate of borderline patients developing PAH was 19% after 3 years and 27% after 5 years. Accordingly, we may argue that borderline PAP is a ''pre-PAH'' condition in scleroderma. Of course, borderline elevation of PAP may be caused not only by pulmonary vasculopathy but also by cardiac or pulmonary co-morbidities [5]. In these cases borderline elevation of PAP may be considered as a general prognostic marker [5,6].The analysis of Visovatti and colleagues [1] includes several clinical (for example, current/past telangiectasis, presence of peripheral edema), laboratory (for example, ACA antibody, NT-proBNP), lung functional (for example, forced vital capacity (percentage predicted)/diffusion capacity for carbon monoxide ratio) and cardiac (for example, tricuspid annular plane systolic excursion) markers that may distinguish scleroderma patients with borderline PAP elevation from those with normal PAP or with manifest PAH. According to this analysis, borderline elevation of PAP in scleroderma patients may represent an intermediate stage in the continuum between normal PAP and manifest PAH.Among the DETECT population, 15% of all patients presented with borderline PAP hemodynamics. Although this number may be different in the general scleroderma population, due to the strict inclusion and exclusion criteria of the DETECT study [7], the borderline population seems to be a substantial subgroup. Unfortunately, follow-up data of the described patients in comparison with normal PAP and manifest PAH patients have not been provided. Such data might impact the development of clinical algorithms regarding further follow-up and treatment of these patients.In addition to the borderline elevation of resting PAP, another specific hemodynamic situation in scleroderma patients needs careful interpretation: exercise-induced PAP increase. Earlier studies showed that this may be a frequent condition among scleroderma patients and clinical deterioration and the development of PAH are frequent in this population [2]. In a recent analysis, a strong correlation between resting and exercise PAP values was evident [5], suggesting that patients with borderline hemodynamics and those with a strong PAP increase during exercise may strongly overlap, closing the gap between these two hemodynamic conditions.The most important question remains open: should targeted PAH therapy be offered to scleroderma patients with borderline PAP or exercise-induced PAP increase? Unfortunately there has been no clinical study investigating patients with borderline PAP so far and only two small studies have selected patients with exercise-induced PAP increase [8,9]. The results of these studies are promising, but need to be confirmed in adequately powered, randomized, prospective trials.Based on a series of studies indicating borderline hemodynamics has an important role in scleroderma patients with regard to the development of PAH and potentially for early treatment, future studies should aim for clear evidence for diagnostic and therapeutic algorithms for this patient population. This may contribute to a substantial prognostic improvement for patients with scleroderma who develop pulmonary vasculopathy     

Functional,radiological and biological markers of alveolitis and infections of the lower respiratory tract in patients with systemic sclerosis

Background

A progressive lung disease and a worse survival have been observed in patients with systemic sclerosis and alveolitis. The objective of this study was to define the functional, radiological and biological markers of alveolitis in SSc patients.

Methods

100 SSc patients (76 with limited and 24 with diffuse disease) underwent a multistep assessment of cardiopulmonary system: pulmonary function tests (PFTs) every 6–12 months, echocardiography, high resolution computed tomography (HRCT) and bronchoalveolar lavage (BAL), if clinically advisable. Alveolar and interstitial scores on HRCT and IL-6 plasma levels were also assessed as lung disease activity indices.

Results

90 SSc patients with abnormal PFTs and 3 with signs and/or symptoms of lung involvement and normal PFTs underwent HRCT and echocardiography. HRCT revealed evidence of fibrosis in 87 (93.5%) patients, with 55 (59.1%) showing both ground glass attenuation and fibrosis. In 42 patients who had exhibited ground glass on HRCT and consented to undergo BAL, 16 (38.1%) revealed alveolitis. 12 (75%) of these patients had restrictive lung disease (p < 0.0001) and presented diffuse skin involvement (p = 0.0009). IL-6 plasma levels were higher in patients with alveolitis than in patients without (p = 0.041). On logistic regression model the best independent predictors of alveolitis were diffuse skin involvement (OR(95%CIs):12.80(2.54–64.37)) and skin score > 14 (OR(95%CIs):7.03(1.40–34.33)). The alveolar score showed a significant correlation with IL-6 plasma levels (r = 0.36, p = 0.001) and with the skin score (r = 0.33, p = 0.001). Cultures of BAL fluid resulted positive in 10 (23.8%) of the 42 patients that underwent BAL and after one year a deterioration in PFTs occurred in 8 (80%) of these patients (p = 0.01). Pulmonary artery systolic pressure ≥ 40 mmHg was found in 6 (37.5%) patients with alveolitis.

Conclusion

We found alveolitis only in 38.1% of the patients who had exhibited ground glass on HRCT and then underwent BAL, probably because the concomitant fibrosis influenced results. A diffuse skin involvement and a restrictive pattern on PFTs together with ground glass on HRCT were judged possible markers of alveolitis, a BAL examination being indicated as the next step. Nevertheless BAL would be necessary to detect any infections of the lower respiratory tract that may cause further deterioration in lung function.     

Pulmonary circulation and right ventricular function in primary arterial hypertension]

Selected parameters of the pulmonary circulation and right ventricular performance were studied in 30 patients with primary arterial hypertension. Four patients belonged to the WHO class I, four to class I/II, 18 to class II and the remaining four to class III. Patients were eligible, if they were in sinus rhythm, without symptoms of left ventricular failure and diseases that night influence pulmonary pressures, and if drugs affecting cardiac performance could be withdrawn safely for 3 days. Ten healthy subjects served as control group. The mean pulmonary capillary wedge pressure and mean pulmonary artery pressure were similar in both groups. In contrast, the systolic pulmonary arterial pressure exceeded 30 mm Hg in 6 patients. Mean pulmonary vascular resistance was higher in examined patients than in the control group. Right ventricular end-diastolic pressure was above 5 mm Hg in as much as 50% of patients. Mean systolic ejection rate showed a tendency to decrease. The results indicate that part of patients with primary arterial hypertension exhibits disorders in the pulmonary circulation and right ventricular performance.     

Arterial Blood Pressure Is Closely Related to Ascites Development in Compensated HCV-Related Cirrhosis

Background

Arterial blood pressure (BP) is a reliable marker of circulatory dysfunction in cirrhotic patients. There are no prospective studies evaluating the association between different levels of arterial BP and ascites development in compensated cirrhotic patients. Therefore, we evaluated the relationship between arterial BP and ascites development in compensated cirrhotic patients.

Materials and Methods

A total of 402 patients with compensated HCV-related cirrhosis were prospectively followed during 6 years to identify ascites development. At baseline, patients underwent systolic, diastolic and mean arterial pressure (MAP) measurements. Any history of arterial hypertension was also recorded. The occurrence of events such as bleeding, hepatocellular carcinoma, death and liver transplantation prior to ascites development were considered as competing risk events.

Results

Over a median of 156 weeks, ascites occurred in 54 patients (13%). At baseline, MAP was significantly lower in patients with ascites development (75.9 mm/Hg [95%CI, 70.3–84.3]) than those without ascites (93.6 mm/Hg [95% CI: 86.6–102.3]). After adjusting for covariates, the 6-year cumulative incidence of ascites was 40% (95%CI, 34%–48%) for patients with MAP<83.32 mm/Hg. In contrast, cumulative incidences of ascites were almost similar among patients with MAP values between 83.32 mm/Hg and 93.32 mm/Hg (7% [95% CI: 4%–12%]), between 93.32 mm/Hg and 100.31 mm/Hg (5% [95% CI: 4%–11%]) or higher than 100.31 mm/Hg (3% [95% CI: 1%–6%]). The MAP was an independent predictor of ascites development.

Conclusions

The MAP is closely related to the development of ascites in compensated HCV-related cirrhosis. The risk of ascites development increases in 4.4 fold for subjects with MAP values <83.32 mm/Hg.     

Predictors of positive airway pressure therapy termination in the first year: analysis of big data from a German homecare provider

Background

There is a lack of robust data about factors predicting continuation (or termination) of positive airway pressure therapy (PAP) for sleep apnea. This analysis of big data from a German homecare provider describes patients treated with PAP, analyzes the therapy termination rate over the first year, and investigates predictive factors for therapy termination.

Methods

Data from a German homecare service provider were analyzed retrospectively. Patients who had started their first PAP therapy between September 2009 and April 2014 were eligible. Patient demographics, therapy start date, and the date of and reason for therapy termination were obtained. At 1?year, patients were classified as having compliance-related therapy termination or remaining on therapy. These groups were compared, and significant predictors of therapy termination determined.

Results

Of 98,329 patients included in the analysis, 11,702 (12%) terminated PAP therapy within the first year (after mean 171?±?91?days). There was a U-shaped relationship between therapy termination and age; therapy termination was higher in the youngest (<?30?years, 15.5%) and oldest (≥ 80?years, 19.8%) patients, and lower in those aged 50–59?years (9.9%). Therapy termination was significantly more likely in females versus males (hazard ratio 1.48, 95% confidence interval 1.42–1.54), in those with public versus private insurance (1.75, 1.64–1.86) and in patients whose first device was automatically adjusting or fixed-level continuous positive airway pressure versus bilevel or adaptive servo-ventilation (1.28, 1.2–1.38).

Conclusions

This analysis of the largest dataset investigating PAP therapy termination identified a number of predictive factors. These can help health care providers chose the most appropriate PAP modality, identify specific patient phenotypes at higher risk of stopping PAP and target interventions to support ongoing therapy to these groups, as well as allow them to develop a risk stratification tool.

     

In vitro study of flow regulation for pulmonary insufficiency

Given the tolerance of the right heart circulation to mild regurgitation and gradient, we study the potential of using motionless devices to regulate the pulmonary circulation. In addition, we document the flow performance of two mechanical valves. A motionless diode, a nozzle, a mechanical bileaflet valve, and a tilting disk valve were tested in a pulmonary mock circulatory system over the normal human range of pulmonary vascular resistance (PVR). For the mechanical valves, regurgitant fractions (RFs) and transvalvular pressure gradients were found to be weak functions of PVR. On the low end of normal PVR, the bileaflet and tilting disk valves fluttered and would not fully close. Despite this anomaly, the regurgitant fraction of either valve did not change significantly. The values for RF and transvalvular gradient measured varied from 4 to 7% and 4 to 7 mm Hg, respectively, at 5 lpm for all tests. The diode valve was able to regulate flow with mild regurgitant fraction and trivial gradient but with values higher than either mechanical valve tested. Regurgitant fraction ranged from 2 to 17% in tests extending from PVR values of 1 to 4.5 mm Hg/lpm at 5 lpm and with concomitant increases in gradient up to 17 mm Hg. The regurgitant fraction for the nozzle increased from 2 to 23% over the range of PVR with gradients increasing to 18 mm Hg. The significant findings were: (1) the mechanical valves controlled regurgitation at normal physiological cardiac output and PVR even though they failed to close at some normal values of PVR and showed leaflet flutter; and (2) it may be possible to regulate the pulmonary circulation to tolerable levels using a motionless pulmonary valve device.     

Neonatal intermittent hypoxia and hypertension

Obstructive apnea during sleep is accompanied by intermittent hypoxia (IH) leading to hypertension and other cardiovascular disturbances. A comparative evaluation of long-term effects of the neonatal IH on the cardiovascular functions was performed in normotensive Sprague-Dawley and spontaneously hypertensive rats (SHR). The newborn rats were placed for 30 days to conditions of IH (8% and 21% O₂, alternating every 90 s for 12 h/day). Control groups of rats were constantly kept in normoxia. By 6 months, in the spontaneously hypertensive rats exposed to IH at the period of wakefulness there was a statistically significant increase (as compared with control) of the systolic (185.8 ± 1.7 and 169.9 ± 1.4 mm Hg, correspondingly, p < 0.010 and the diastolic pressure (96.2 ± 4.9 and 86.0 ± 2.6 mm Hg, correspondingly, p < 0.01). During sleep, the systolic and diastolic pressure in these rats was higher than in control animals by 10 mm Hg (p < 0.01) and 12 mm Hg (p < 0.01), its decrease during sleep being absent. In SHR submitted to IH there was an increase in the power ratio of the heart rate variability from 0.9 ± 0.15 to 1.5 ± 0.17, which indicates a shift of the sympathico-parasympathetic balance in this group towards predominance of the sympathetic component. In the Sprague-Dawley rats exposed to neonatal hypoxia, the above-indicated changes were not prominent. These peculiarities of the hypertensive rats allow establishing connection of the genetic factor with the sympathetic mechanism providing long-term consequences of the neonatal IH for the cardiovascular control in the SHR.     

Simvastatin ameliorates established pulmonary hypertension through a heme oxygenase-1 dependent pathway in rats

Background

Simvastatin has been shown to ameliorate pulmonary hypertension by several mechanisms in experimental animal models. In this study, we hypothesized that the major benefits of simvastatin in pulmonary hypertension occur via the heme oxygenase-1 pathway.

Methods

Simvastatin (10 mg/kgw/day) was tested in two rat models of pulmonary hypertension (PH): monocrotaline administration and chronic hypoxia. The hemodynamic changes, right heart hypertrophy, HO-1 protein expression, and heme oxygenase (HO) activity in lungs were measured in both models with and without simvastatin treatment. Tin-protoporphyrin (SnPP, 20 μmol/kg w/day), a potent inhibitor of HO activity, was used to confirm the role of HO-1.

Results

Simvastatin significantly ameliorated pulmonary arterial hypertension from 38.0 ± 2.2 mm Hg to 22.1 ± 1.9 mm Hg in monocrotaline-induced PH (MCT-PH) and from 33.3 ± 0.8 mm Hg to 17.5 ± 2.9 mm Hg in chronic hypoxia-induced PH (CH-PH) rats. The severity of right ventricular hypertrophy was significantly reduced by simvastatin in MCT-PH and CH-PH rats. Co-administration with SnPP abolished the benefits of simvastatin. Simvastatin significantly increased HO-1 protein expression and HO activity in the lungs of rats with PH; however co-administration of SnPP reduced HO-1 activity only. These observations indicate that the simvastatin-induced amelioration of pulmonary hypertension was directly related to the activity of HO-1, rather than its expression.

Conclusion

This study demonstrated that simvastatin treatment ameliorates established pulmonary hypertension primarily through an HO-1-dependent pathway.     

Membrane diffusion- and capillary blood volume measurements are not useful as screening tools for pulmonary arterial hypertension in systemic sclerosis: a case control study

Background

Lung injury caused by both inhaled dusts and infectious agents depends on increased availability of iron and metal-catalyzed oxidative stress. Because inhaled particles, such as silica, and certain infections can cause secondary pulmonary alveolar proteinosis (PAP), we tested the hypothesis that idiopathic PAP is associated with an altered iron homeostasis in the human lung.

Methods

Healthy volunteers (n = 20) and patients with idiopathic PAP (n = 20) underwent bronchoalveolar lavage and measurements were made of total protein, iron, tranferrin, transferrin receptor, lactoferrin, and ferritin. Histochemical staining for iron and ferritin was done in the cell pellets from control subjects and PAP patients, and in lung specimens of patients without cardiopulmonary disease and with PAP. Lavage concentrations of urate, glutathione, and ascorbate were also measured as indices of oxidative stress.

Results

Lavage concentrations of iron, transferrin, transferrin receptor, lactoferrin, and ferritin were significantly elevated in PAP patients relative to healthy volunteers. The cells of PAP patients had accumulated significant iron and ferritin, as well as considerable amounts of extracellular ferritin. Immunohistochemistry for ferritin in lung tissue revealed comparable amounts of this metal-storage protein in the lower respiratory tract of PAP patients both intracellularly and extracellularly. Lavage concentrations of ascorbate, glutathione, and urate were significantly lower in the lavage fluid of the PAP patients.

Conclusion

Iron homeostasis is altered in the lungs of patients with idiopathic PAP, as large amounts of catalytically-active iron and low molecular weight anti-oxidant depletion are present. These findings suggest a metal-catalyzed oxidative stress in the maintenance of this disease.     

Iron homeostasis and oxidative stress in idiopathic pulmonary alveolar proteinosis: a case-control study

Background

Lung injury caused by both inhaled dusts and infectious agents depends on increased availability of iron and metal-catalyzed oxidative stress. Because inhaled particles, such as silica, and certain infections can cause secondary pulmonary alveolar proteinosis (PAP), we tested the hypothesis that idiopathic PAP is associated with an altered iron homeostasis in the human lung.

Methods

Healthy volunteers (n = 20) and patients with idiopathic PAP (n = 20) underwent bronchoalveolar lavage and measurements were made of total protein, iron, tranferrin, transferrin receptor, lactoferrin, and ferritin. Histochemical staining for iron and ferritin was done in the cell pellets from control subjects and PAP patients, and in lung specimens of patients without cardiopulmonary disease and with PAP. Lavage concentrations of urate, glutathione, and ascorbate were also measured as indices of oxidative stress.

Results

Lavage concentrations of iron, transferrin, transferrin receptor, lactoferrin, and ferritin were significantly elevated in PAP patients relative to healthy volunteers. The cells of PAP patients had accumulated significant iron and ferritin, as well as considerable amounts of extracellular ferritin. Immunohistochemistry for ferritin in lung tissue revealed comparable amounts of this metal-storage protein in the lower respiratory tract of PAP patients both intracellularly and extracellularly. Lavage concentrations of ascorbate, glutathione, and urate were significantly lower in the lavage fluid of the PAP patients.

Conclusion

Iron homeostasis is altered in the lungs of patients with idiopathic PAP, as large amounts of catalytically-active iron and low molecular weight anti-oxidant depletion are present. These findings suggest a metal-catalyzed oxidative stress in the maintenance of this disease.     

Mouse anaphylactic shock is caused by reduced cardiac output,but not by systemic vasodilatation or pulmonary vasoconstriction,via PAF and histamine

Aims

Systemic anaphylaxis is life-threatening, and its pathophysiology is not fully clarified. Mice are frequently used for experimental study on anaphylaxis. However, the hemodynamic features and mechanisms of mouse anaphylactic hypotension remain unknown. Therefore, we determined mechanisms of systemic and pulmonary vascular response to anaphylactic hypotension in anesthetized BALB/c mice by using receptor antagonists of chemical mediators.

Main methods

Anaphylaxis was actively induced by an intravenous injection of the ovalbumin antigen into open-chest artificially ventilated sensitized mice. Mean arterial pressure (MAP), pulmonary arterial pressure (PAP), left atrial pressure, central venous pressure, and aortic blood flow (ABF) were continuously measured.

Key findings

In sensitized control mice, MAP and ABF showed initial, transient increases, followed by progressive decreases after the antigen injection. Total peripheral resistance (TPR) did not decrease, while PAP initially and transiently increased to 18.5 ± 0.5 mm Hg and pulmonary vascular resistance (PVR) also significantly increased. The antigen-induced decreases in MAP and ABF were attenuated by pretreatment with either a platelet-activating factor (PAF) receptor antagonist, CV6209, or a histamine H₁ receptor antagonist, diphenhydramine, and were abolished by their combination. Diphenhydramine augmented the initial increases in PAP and PVR, but did not affect the decrease of the corresponding MAP fall. The antagonists of either leukotriene C₄ or serotonin, alone or in combination with CV6209, exerted no significant effects.

Significance

Mouse anaphylactic hypotension is caused by a decrease in cardiac output but not vasodilatation, via actions of PAF and histamine. The slight increase in PAP is not involved in mouse anaphylactic hypotension.     

Stress Doppler echocardiography for early detection of systemic sclerosis-associated pulmonary arterial hypertension

IntroductionIn patients with systemic sclerosis (SSc), associated pulmonary arterial hypertension (SSc-APAH) is the leading cause of death. The objective of this prospective screening study was to analyse sensitivity and specificity of stress Doppler echocardiography (SDE) in detecting pulmonary hypertension (PH).MethodsPulmonary artery pressures and further parameters of PH were assessed by echocardiography and right heart catheterisation (RHC) at rest and during exercise in patients with SSc. Investigators of RHC were blinded to the results of non-invasive measurements.ResultsOf 76 patients with SSc (64 were female and mean age was 58±14 years), 22 (29 %) had manifest PH confirmed by RHC: four had concomitant left heart diseases, three had lung diseases, and 15 had SSc-APAH. Echocardiography at rest missed PH diagnosis in five of 22 patients with PH when a cutoff value for systolic pulmonary arterial pressure (PASP) was more than 40 mm Hg at rest. The sensitivity of echocardiography at rest was 72.7 % (95 % confidence interval (CI) 0.52–0.88), and specificity was 88.2 % (95 % CI 0.78–0.95). When a cutoff value for PASP was more than 45 mm Hg during low-dose exercise, SDE missed PH diagnosis in one of the 22 patients with PH and improved sensitivity to 95.2 % (95 % CI 0.81–1.0) but reduced specificity to 84.9 % (95 % CI 0.74–0.93). Reduction of specificity was partly due to concomitant left heart disease.ConclusionsThe results of this prospective cross-sectional study using RHC as gold standard in all patients showed that SDE markedly improved sensitivity in detecting manifest PH to 95.2 % compared with 72.7 % using echocardiography at rest only. Thus, for PH screening in patients with SSc, echocardiography should be performed at rest and during exercise.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01387035","term_id":"NCT01387035"}}NCT01387035. Registered 29 June 2011.     

Safety and efficacy of balloon pulmonary angioplasty in chronic thromboembolic pulmonary hypertension in the Netherlands

Background

Balloon pulmonary angioplasty (BPA) is an emerging treatment in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic disease (CTED). We describe the first safety and efficacy results of BPA in the Netherlands.

Methods

We selected all consecutive patients with inoperable CTEPH and CTED accepted for BPA treatment who had a six-month follow-up in the St. Antonius Hospital in Nieuwegein and the Amsterdam University Medical Center (UMC) in Amsterdam. Functional class (FC), N?terminal pro-brain natriuretic peptide (NT-proBNP), 6?minute walking test distance (6MWD) and right-sided heart catheterisation were performed at baseline and six months after last BPA. Complications for each BPA procedure were noted.

Results

A hundred and seventy-two BPA procedures were performed in 38 patients (61% female, mean age 65?±?15 years). Significant improvements six months after BPA treatment were observed for functional class (63% FC I/II to 90% FC I/II, p?=?0.014), mean pulmonary artery pressure (?8.9?mm?Hg, p?=?0.0001), pulmonary vascular resistance (?2.8 Woods Units (WU), p?=?0.0001), right atrial pressure (?2.0?mm?Hg, p?=?0.006), stroke volume index (+5.7?ml/m², p?=?0.009) and 6MWD (+48m, p?=?0.007). Non-severe complications occurred in 20 (12%) procedures.

Conclusions

BPA performed in a CTEPH expert centre is an effective and safe treatment in patients with inoperable CTEPH.

     

Detection of Pancreatic Carcinomas by Imaging Lactose-Binding Protein Expression in Peritumoral Pancreas Using [18F]Fluoroethyl-Deoxylactose PET/CT

Background

Early diagnosis of pancreatic carcinoma with highly sensitive diagnostic imaging methods could save lives of many thousands of patients, because early detection increases resectability and survival rates. Current non-invasive diagnostic imaging techniques have inadequate resolution and sensitivity for detection of small size (∼2–3 mm) early pancreatic carcinoma lesions. Therefore, we have assessed the efficacy of positron emission tomography and computer tomography (PET/CT) imaging with β-O-D-galactopyranosyl-(1,4′)-2′-deoxy-2′-[¹⁸F]fluoroethyl-D-glucopyranose ([¹⁸F]FEDL) for detection of less than 3 mm orthotopic xenografts of L3.6pl pancreatic carcinomas in mice. [¹⁸F]FEDL is a novel radioligand of hepatocarcinoma-intestine-pancreas/pancreatitis-associated protein (HIP/PAP), which is overexpressed in peritumoral pancreatic acinar cells.

Methodology/Principal Findings

Dynamic PET/CT imaging demonstrated rapid accumulation of [¹⁸F]FEDL in peritumoral pancreatic tissue (4.04±2.06%ID/g), bi-exponential blood clearance with half-lives of 1.65±0.50 min and 14.14±3.60 min, and rapid elimination from other organs and tissues, predominantly by renal clearance. Using model-independent graphical analysis of dynamic PET data, the average distribution volume ratio (DVR) for [¹⁸F]FEDL in peritumoral pancreatic tissue was estimated as 3.57±0.60 and 0.94±0.72 in sham-operated control pancreas. Comparative analysis of quantitative autoradiographic images and densitometry of immunohistochemically stained and co-registered adjacent tissue sections demonstrated a strong linear correlation between the magnitude of [¹⁸F]FEDL binding and HIP/PAP expression in corresponding regions (r = 0.88). The in situ analysis demonstrated that at least a 2–4 fold apparent lesion size amplification was achieved for submillimeter tumors and to nearly half a murine pancreas for tumors larger than 3 mm.

Conclusion/Significance

We have demonstrated the feasibility of detection of early pancreatic tumors by non-invasive imaging with [¹⁸F]FEDL PET/CT of tumor biomarker HIP/PAP over-expressed in peritumoral pancreatic tissue. Non-invasive non-invasive detection of early pancreatic carcinomas with [¹⁸F]FEDL PET/CT imaging should aid the guidance of biopsies and additional imaging procedures, facilitate the resectability and improve the overall prognosis.     

Plasma levels and cardiovascular gene expression of urotensin-II in human heart failure

The peptide urotensin-II (U-II) has been described as most potent vasoconstrictor identified so far, but plasma values in humans and its role in cardiovascular pathophysiology are unknown. We investigated circulating urotensin-II and its potential role in human congestive heart failure (CHF). We enrolled control individuals (n=13; cardiac index [CI], 3.5+/-0.1 l/min/m2; pulmonary wedge pressure [PCWP], 10+/-1 mm Hg), patients with moderate (n=10; CI, 2.9+/-0.3 l/min/m2; PCWP, 14+/-2 mm Hg) and severe CHF (n=11; CI, 1.8+/-0.2 l/min/m2; PCWP, 33+/-2 mm Hg). Plasma levels of urotensin-II differed neither between controls, patients with moderate and severe CHF nor between different sites of measurement (pulmonary artery, left ventricle, coronary sinus, antecubital vein) within the single groups. Hemodynamic improvement by vasodilator therapy in severe CHF (CI, +78+/-3%; PCWP, -55+/-3%) did not affect circulating U-II over 24 h. Preprourotensin-II mRNA expression in right atria, left ventricles, mammary arteries and saphenous veins did not differ between controls with normal heart function and patients with end-stage CHF. In conclusion, urotensin-II plasma levels and its myocardial and vascular gene expression are unchanged in human CHF. Circulating urotensin-II does not respond to acute hemodynamic improvement. These findings suggest that urotensin-II does not play a major role in human CHF.     

Pulmonary oedema without critical increase in left atrial pressure in acute myocardial infarction.

Twelve patients with acute myocardial infarction and radiological evidence of pulmonary oedema were observed in whom the left atrial pressure, measured indirectly as pulmonary artery end-diastolic pressure, was not critically increased (range 5-12 mm Hg with reference to sternal angle). Eight of the patients had been treated with frusemide, but only six had responded: hence in at least half of the series diuresis could not account for the anomalous finding. Six patients with low cardiac output were given infusions to expand plasma volume. Appreciable increments in mean values for cardiac index (1.6 to 2.0 1/min/m2), stroke index (18 to 23 ml/beat/m2), mean arterial pressure (65 to 86 mm Hg), and pulmonary artery end-diastolic pressure (8 to 15 mm Hg) were recorded. This group, and the remaining six patients with higher cardiac output, survived to leave hospital. Delay in radiographic clearing after a fall of left atrial pressure was a possible explanation for the relatively low pulmonary artery end-diastolic pressures, especially in the patients treated successfully with diuretics. Other mechanisms, such as alterations in pulmonary vascular permeability, might also have contributed to the syndrome. Pulmonary oedema without a critical increase in the left atrial pressure is unusual in acute myocardial infarction but the therapeutic implications are important. Withdrawal;of diuretics may be indicated, and in some cases expansion of plasma volume may lead to striking clinical improvement.     

Telmisartan in the treatment of hypertension in patients with chronic renal insufficiency

The primary aim of this study was evaluation of the efficacy of telmisartan (angiotensin II receptor blocker- AT(1) blocker) on blood pressure in 10 patients with renal impairment in moderate or advanced stages of renal insufficiency and not dependent on haemodialysis. Its effect on proteinuria, renal function (represented by serum urea, creatinine, glomerular filtration), evaluation of overall therapy compliance in comparison with a previously prescribed angiotensin converting enzyme inhibitors (ACEI) were secondary aims. Considering the presence of left ventricle hypertrophy in all patients as a marker of hypertensive cardiopathy, the effect of telmisartan therapy on non-invasive cardiovascular parameters (ECG, echocardiography, and assessment of heart rate variability-HRV) was also evaluated. The study group involved 10 hypertensive patients (6 women, 4 men) with diabetic and non-diabetic renal impairment, proteinuria above 1 g/24 hours, hypertensive cardiopathy and intolerance of ACEI (cough). Telmisartan was added to their long-term antihypertensive combination therapy in a dose of 40 mg for the first 14 days, after which the dose increased to the maximal of 80 mg. The average initial daytime systolic blood pressure (SBP) was 149 +/- 19.7 mm Hg, average night-time SBP 145 +/- 23.0 mm Hg, average initial daytime diastolic BP (DBP) 90.6 +/- 2.5 mm Hg, night-time DBP 88.9 +/- 13.5 mm Hg. Average initial serum creatinine was 207.2 +/- 48.5 micromol/l, urea 15.1 +/- 4.4 mmol/l, GF 0.5 +/- 0.1 ml/s. Echocardiography revealed left ventricular (LV) hypertrophy with well preserved systolic and moderately impaired diastolic LV function. Also the HRV assessment revealed impaired neurovegetative (e.g. sympathovagal) balance. After 1 year of combination therapy with telmisartan, there was a clearly significant reduction in both SBP and DBP in both day and night-time (SBP daytime 149.6 vs.116.6 mm Hg, night-time 145.8 vs. 129.5 mm Hg; DBP daytime 90.6 vs. 83.5 mm Hg, night-time 88.9 vs. 79.3 mm Hg) and proteinuria (2.37 vs. 1.27 g/24 hour, p < 0.05). There were no significant changes in serum creatinine, urea values, and LV functions. On the other hand, further progression of the sympathovagal balance impairment was noted (continuing reduction of HRV in 9 from 10 patients), which can be described as the priority finding. The total compliance of telmisartan therapy was very good and without adverse clinical side effects. In conclusion - telmisartan reduces blood pressure and proteinuria safely and effectively in patients with various types of nephropathy in moderate or advanced stages of renal insufficiency.