Microvascular Disease in Chronic Thromboembolic Pulmonary Hypertension: Hemodynamic Phenotyping and Histomorphometric Assessment.

BACKGROUND: Pulmonary endarterectomy (PEA) is the gold standard treatment for patients with operable chronic thromboembolic pulmonary hypertension. However, persistent pulmonary hypertension (PH) after PEA remains a major determinant of poor prognosis. A concomitant small-vessel arteriopathy in addition to major pulmonary artery obstruction has been suggested to play an important role in the development of persistent PH and survival after PEA. One of the greatest unmet needs in the current preoperative evaluation is to assess the presence and severity of small-vessel arteriopathy. Using the pulmonary artery occlusion technique, we sought to assess the presence and degree of small-vessel disease in patients with chronic thromboembolic pulmonary hypertension undergoing PEA to predict postoperative outcome before surgery. METHODS: Based on pulmonary artery occlusion waveforms yielding an estimate of the effective capillary pressure, we partitioned pulmonary vascular resistance in larger arterial (upstream resistance [Rup]) and small arterial plus venous components (downstream resistance) in 90 patients before PEA. For validation, lung wedge biopsies were taken from nonobstructed and obstructed lung territories during PEA in 49 cases. Biopsy sites were chosen according to the pulmonary angiogram still frames that were mounted in the operating room. All vessels per specimen were measured in each patient. Percent media (%MT; arteries) and intima thickness (%IT; arteries, veins, and indeterminate vessels) were calculated relative to external vessel diameter. RESULTS: Decreased Rup was an independent predictor of persistent PH (odds ratio per 10%, 0.40 [95% CI, 0.23-0.69]; P=0.001) and survival (hazard ratio per 10%, 0.03 [95% CI, 0.00-0.33]; p=0.004). Arterial %MT and %IT of nonobstructed lung territories and venous %IT of obstructed lung territories were significantly increased in patients with persistent PH and nonsurvivors. Rup correlated inversely with %MT (r=-0.72, P<0.001) and %IT (r=-0.62, P<0.001) of arteries from nonobstructed lung territories and with %IT (r=-0.44, P=0.024) of veins from obstructed lung territories. Receiver operating characteristic analysis disclosed that Rup <66% predicted persistent PH after PEA, whereas Rup <60% identified patients with poor prognosis after PEA. CONCLUSIONS: Pulmonary artery occlusion waveform analysis with estimation of Rup seems to be a valuable technique for assessing the degree of small-vessel disease and postoperative outcome after PEA in chronic thromboembolic pulmonary hypertension.

In-depth haemodynamic phenotyping of pulmonary hypertension due to left heart disease.

The commonest cause of pulmonary hypertension (PH) is left heart disease (LHD). The current classification system for definitions of PH-LHD is under review. We therefore performed prospective in-depth invasive haemodynamic phenotyping in order to assess the site of increased pulmonary vascular resistance (PVR) in PH-LHD subsets.Based on pulmonary artery occlusion waveforms yielding an estimate of the effective capillary pressure, we partitioned PVR in larger arterial (Rup, upstream resistance) and small arterial plus venous components (Rds, downstream resistance). In the case of small vessel disease, Rup decreases and Rds increases. Inhaled nitric oxide (NO) testing was used to assess acute vasoreactivity.Right ventricular afterload (PVR, pulmonary arterial compliance and effective arterial elastance) was significantly higher in combined post- and pre-capillary PH (Cpc-PH, n=35) than in isolated post-capillary PH (Ipc-PH, n=20). Right ventricular afterload decreased during inhalation of NO in Cpc-PH and idiopathic pulmonary arterial hypertension (n=31), but remained unchanged in Ipc-PH. Rup was similar in Cpc-PH (66.8±10.8%) and idiopathic pulmonary arterial hypertension (65.0±12.2%; p=0.530) suggesting small vessel disease, but significantly higher in Ipc-PH (96.5±4.5%; p<0.001) suggesting upstream transmission of elevated left atrial pressure.Right ventricular afterload is driven by elevated left atrial pressure in Ipc-PH and is further increased by elevated small vessel resistance in Cpc-PH. Cpc-PH is responsive to inhaled NO. Our data support current definitions of PH-LHD subsets.

Coronary neutrophil extracellular trap burden and deoxyribonuclease activity in ST-elevation acute coronary syndrome are predictors of ST-segment resolution and infarct size.

RATIONALE: Mechanisms of coronary occlusion in ST-elevation acute coronary syndrome are poorly understood. We have previously reported that neutrophil (polymorphonuclear cells [PMNs]) accumulation in culprit lesion site (CLS) thrombus is a predictor of cardiovascular outcomes. OBJECTIVE: The goal of this study was to characterize PMN activation at the CLS. We examined the relationships between CLS neutrophil extracellular traps (NETs), bacterial components as triggers of NETosis, activity of endogenous deoxyribonuclease, ST-segment resolution, and infarct size. METHODS AND RESULTS: We analyzed coronary thrombectomies from 111 patients with ST-elevation acute coronary syndrome undergoing primary percutaneous coronary intervention. Thrombi were characterized by immunostaining, flow cytometry, bacterial profiling, and immunometric and enzymatic assays. Compared with femoral PMNs, CLS PMNs were highly activated and formed aggregates with platelets. Nucleosomes, double-stranded DNA, neutrophil elastase, myeloperoxidase, and myeloid-related protein 8/14 were increased in CLS plasma, and NETs contributed to the scaffolds of particulate coronary thrombi. Copy numbers of Streptococcus species correlated positively with dsDNA. Thrombus NET burden correlated positively with infarct size and negatively with ST-segment resolution, whereas CLS deoxyribonuclease activity correlated negatively with infarct size and positively with ST-segment resolution. Recombinant deoxyribonuclease accelerated the lysis of coronary thrombi ex vivo. CONCLUSIONS: PMNs are highly activated in ST-elevation acute coronary syndrome and undergo NETosis at the CLS. Coronary NET burden and deoxyribonuclease activity are predictors of ST-segment resolution and myocardial infarct size.

Pulmonary Hypertension in Heart Failure. Epidemiology, Right Ventricular Function, and Survival.

RATIONALE: Patients with pulmonary hypertension due to left heart disease (PH-LHD) and a diastolic pulmonary vascular pressure gradient ≥ 7 mm Hg, representing PH out of proportion to pulmonary arterial wedge pressure, have pulmonary vascular disease and increased mortality. Little information exists on this condition, recently labeled as "combined pre- and post-capillary PH" (Cpc-PH). OBJECTIVES: To investigate epidemiology, risk factors, right ventricular function, and outcomes in patients with chronic heart failure and Cpc-PH. METHODS: The study population was identified from a retrospective chart review of a clinical database of 3,107 stable patients who underwent first diagnostic right heart catheterization and from a prospective cohort of 800 consecutive patients at a national university-affiliated tertiary center. MEASUREMENTS AND MAIN RESULTS: The retrospective cohort had 664 patients with systolic heart failure (SHF) and 399 patients with diastolic heart failure (DHF), 12% of whom were classified as Cpc-PH. The prospective cohort had 172 patients with SHF (14% Cpc-PH) and 219 patients with DHF (12% Cpc-PH). Chronic obstructive pulmonary disease (P = 0.034) and the tricuspid annular plane systolic excursion to systolic pulmonary artery pressure ratio (P = 0.015) predicted Cpc-PH in SHF. Younger age (P = 0.004), valvular heart disease (P = 0.046), and the tricuspid annular plane systolic excursion to systolic pulmonary artery pressure ratio predicted Cpc-PH in DHF (P = 0.016). Right ventricular-pulmonary vascular coupling was worse in Cpc-PH patients (end-systolic elastance to effective arterial elastance [Ees/Ea]: SHF: 1.05 ± 0.25; P = 0.002; DHF: 1.17 ± 0.27; P = 0.027) than in those with isolated post-capillary PH (Ees/Ea: SHF: 1.52 ± 0.51; DHF: 1.45 ± 0.29). CONCLUSIONS: Cpc-PH is rare in chronic heart failure. Right ventricular-pulmonary vascular coupling is poor in Cpc-PH and could be one explanation for dismal outcomes.

Defective angiogenesis delays thrombus resolution: a potential pathogenetic mechanism underlying chronic thromboembolic pulmonary hypertension.

OBJECTIVE: Restoration of patency is a natural target of vascular remodeling after venous thrombosis that involves vascular endothelial cells and smooth muscle cells, as well as leukocytes. Acute pulmonary emboli usually resolve <6 months. However, in some instances, thrombi transform into fibrous vascular obstructions, resulting in occlusion of the deep veins, or in chronic thromboembolic pulmonary hypertension (CTEPH). We proposed that dysregulated thrombus angiogenesis may contribute to thrombus persistence. APPROACH AND RESULTS: Mice with an endothelial cell-specific conditional deletion of vascular endothelial growth factor receptor 2/kinase insert domain protein receptor were used in a model of stagnant flow venous thrombosis closely resembling human deep vein thrombosis. Biochemical and functional analyses were performed on pulmonary endarterectomy specimens from patients with CTEPH, a human model of nonresolving venous thromboembolism. Endothelial cell-specific deletion of kinase insert domain protein receptor and subsequent ablation of thrombus vascularization delayed thrombus resolution. In accordance with these findings, organized human CTEPH thrombi were largely devoid of vascular structures. Several vessel-specific genes, such as kinase insert domain protein receptor, vascular endothelial cadherin, and podoplanin, were expressed at lower levels in white CTEPH thrombi than in organizing deep vein thrombi and organizing thrombi from aortic aneurysms. In addition, red CTEPH thrombi attenuated the angiogenic response induced by vascular endothelial growth factor. CONCLUSIONS: In the present work, we propose a mechanism of thrombus nonresolution demonstrating that endothelial cell-specific deletion of kinase insert domain protein receptor abates thrombus vessel formation, misguiding thrombus resolution. Medical conditions associated with the development of CTEPH may be compromising early thrombus angiogenesis.

Exhaled nitric oxide measurement to monitor pulmonary hypertension in a pneumonectomy-monocrotaline rat model.

The use of fractional exhaled nitric oxide (FeNO) has been suggested as a quantitative marker for pulmonary arterial hypertension (PAH) in humans. To further characterize FeNO in PAH we investigated this marker in a rodent model. Since there is no standardized technique for FeNO measurement in animals, we intended to reduce measuring errors and confounders of an existing published method by mathematical modification and tested its applicability in an NO-regulating therapy concept of PAH. Thirty-three male Sprague-Dawley rats underwent unilateral pneumonectomy and monocrotaline (MCT) injection and were observed for 49 days. A telemetric catheter was introduced into the left pulmonary artery to continuously record mean pulmonary arterial pressure (mPAP), and FeNO was assessed. After 35 days, animals were randomized to receive either oral l-arginine (300 mg/kg) in combination with tetrahydrobiopterin (20 mg/kg) therapy (n = 12) or vehicle (n = 11) daily over a period of 14 days. mPAP at baseline was 17.19 ± 9.62 mmHg, which increased to 53.1 ± 10.63 mmHg 28 days after monocrotaline exposure (P < 0.001). Using the modified technique, we found an inverse correlation between exhaled NO and pulmonary pressures before (r = -0.366, P = 0.043) and after MCT (r = -0.363, P = 0.038) as well as after therapy administration (r = -0.657, P = 0.02). Our modified technique proved robust in a rodent model, since valid and reproducible data were gained and showed an inverse correlation between exhaled NO and mPAP, whereas the existing method did not.

Proteomic profiling of acute coronary thrombosis reveals a local decrease in pigment epithelium-derived factor in acute myocardial infarction.

Thrombotic occlusion of an epicardial coronary artery on the grounds of atherosclerotic plaque is considered the ultimate step in AMI (acute myocardial infarction). However, the precise pathophysiological mechanisms underlying acute coronary occlusion are not fully understood. We have analysed proteomic profiles of systemic plasma and plasma derived from the site of coronary plaque rupture of non-diabetic patients with STEMI (ST-segment elevation myocardial infarction). Label-free quantification of MS/MS (tandem MS) data revealed differential regulation of complement cascade components and a decrease in anti-thrombotic PEDF (pigment epithelium-derived factor) between CS (culprit site)-derived plasma and systemic plasma. PEDF, which is known to have a protective role in atherothrombosis, was relatively decreased at the CS, with a level of expression inverse to local MMP-9 (matrix metalloproteinase-9) activity. CS plasma displayed enhanced proteolytic activity towards PEDF. Proteomics of coronary thrombus aspirates indicate that PEDF processing is associated with coronary plaque rupture.

Anti-tumor activities of Panax quinquefolius saponins and potential biomarkers in prostate cancer.

BACKGROUND: Prostate carcinoma is the second most common cancer among men worldwide. Developing new therapeutic approaches and diagnostic biomarkers for prostate cancer (PC) is a significant need. The Chinese herbal medicine Panax quinquefolius saponins (PQS) have been reported to show anti-tumor effects. We hypothesized that PQS exhibits anti-cancer activity in human PC cells and we aimed to search for novel biomarkers allowing early diagnosis of PC. METHODS: We used the human PC cell line DU145 and the prostate epithelial cell line PNT2 to perform cell viability assays, flow cytometric analysis of the cell cycle, and FACS-based apoptosis assays. Microarray-based gene expression analysis was used to display specific gene expression patterns and to search for novel biomarkers. Western blot and quantitative real-time PCR were performed to demonstrate the expression levels of multiple cancer-related genes. RESULTS: Our data showed that PQS inhibited the viability of DU145 cells and induced cell cycle arrest at the G1 phase. A significant decrease in DU145 cell invasion and migration were observed after 24 h treatment by PQS. PQS up-regulated the expression levels of p21, p53, TMEM79, ACOXL, ETV5, and SPINT1 while it down-regulated the expression levels of bcl2, STAT3, FANCD2, DRD2, and TMPRSS2. CONCLUSION: PQS promoted cells apoptosis and inhibited the proliferation of DU145 cells, which suggests that PQS may be effective for treating PC. TMEM79 and ACOXL were expressed significantly higher in PNT2 than in DU145 cells and could be novel biomarker candidates for PC diagnosis.

Pulmonary vascular reactivity and prognosis in patients with chronic thromboembolic pulmonary hypertension: a pilot study.

BACKGROUND: Surgical pulmonary endarterectomy is the preferred treatment for chronic thromboembolic pulmonary hypertension. Persistent pulmonary hypertension after pulmonary endarterectomy has been recognized as a major determinant of poor outcome. We tested whether acute vasoreactivity identifies chronic thromboembolic pulmonary hypertension patients prone to develop persistent/recurrent pulmonary hypertension after pulmonary endarterectomy and whether the degree of acute vasoreactivity affects survival or freedom from lung transplantation. METHODS AND RESULTS: Right-sided heart catheterization at baseline and after inhalation of 40 ppm nitric oxide for 20 minutes was performed in 103 patients (56.3+/-15.3 years old, 53 women). Reductions in mean pulmonary arterial pressure (DeltamPAP; -8.8+/-12.6%; P<0.0001) and pulmonary vascular resistance (-16.1+/-18.1%; P<0.0001) and an increase in mixed venous saturation during inhaled nitric oxide (9.1+/-11.6%; P<0.0001) were observed. Sixty-two patients underwent pulmonary endarterectomy after a median of 49 days (25th and 75th percentiles: 24 and 123 days). Operated patients were followed up for a median of 70.9 months (25th and 75th percentiles: 14 and 97 months). Change in mPAP during inhaled NO was identified as a predictor of persistent/recurrent pulmonary hypertension after pulmonary endarterectomy. Patients experiencing a reduction in mPAP >10.4% with nitric oxide inhalation had a better postoperative outcome. A significant correlation was found between DeltamPAP and immediate postoperative pulmonary vascular resistance (r=0.5, P<0.0001). CONCLUSIONS: A total of 80 (77.7%) of 103 patients demonstrated acute pulmonary vascular reactivity of some degree. A decrease in mPAP >10.4% under inhaled nitric oxide is a predictor of long-term survival and freedom from lung transplantation in adult patients with chronic thromboembolic pulmonary hypertension who are undergoing pulmonary endarterectomy.

Local complement activation triggers neutrophil recruitment to the site of thrombus formation in acute myocardial infarction.

Atherosclerotic plaque rupture with subsequent mural thrombus formation is considered the main event compromising epicardial flow in acute myocardial infarction (AMI). However, the precise mechanisms underlying acute coronary occlusion are unknown. We compared the proteomic profiles of systemic plasma and plasma derived from the site of thrombus formation of patients with AMI by two-dimensional gel electrophoresis and ELISA. We identified a local activation of the complement system, with selective accumulation of the complement activator C-reactive protein (CRP) and the downstream complement effectors C3a and C5a. CRP in coronary thrombus co-localised with C1q and C3 immunoreactivities, suggesting classical complement activation. In vitro, coronary thrombus derived plasma enhanced neutrophil chemotaxis in a C5a dependent fashion. In vivo, neutrophil accumulation at the site of thrombus formation paralleled the time delay from symptom onset to first balloon inflation or aspiration, and was correlated with C5a and enzymatic infarct size. We present the first direct evidence for localised complement activation in acute coronary thrombi. Our data indicate that local complement effectors amplify the vascular occlusion process in AMI by enhanced neutrophil recruitment.

Prognostic value of plasma midregional pro-adrenomedullin and C-terminal-pro-endothelin-1 in chronic heart failure outpatients.

AIMS: The identification of chronic heart failure (CHF) patients at high risk of adverse outcome remains a challenge. New peptides are emerging that may give additional information. In CHF patients, endothelin (ET) levels predict mortality risk. Adrenomedullin has been shown to predict mortality in ischaemic heart failure, but not in unselected or non-ischaemic CHF patients. Moreover, ADM and ET have never been assessed in one model. The aim of the present study was to assess the prognostic value of midregional-pro-adrenomedullin (MR-proADM) and C-terminal-pro-endothelin-1 (CT-proET-1) in outpatients with CHF. METHODS AND RESULTS: We measured plasma MR-proADM and CT-proET-1 levels in 786 consecutive CHF outpatients and compared them with B-type natriuretic peptide (BNP) levels. At 24-month follow-up, 233 patients had died. A stepwise forward Cox regression model with age, sex, estimated glomerular filtration rate, NYHA > II, left ventricular ejection fraction (LVEF), MR-proADM, CT-proET-1, and BNP as possible predictors revealed that MR-proADM levels [hazard ratio (HR) = 1.77, P < 0.001] in addition to age (HR = 1.02, P = 0.004), ejection fraction (HR = 0.98, P = 0.004), and NYHA > II (HR = 1.86, P < 0.001) were predictors of death at 24 months. When the analysis was repeated dependent on NYHA-stage, MR-proADM (HR = 2.12, P < 0.001) and LVEF (HR = 0.96, P = 0.006) were significant markers, but only in patients with mild/moderate CHF. CONCLUSION: Our data suggest that MR-proADM may be an important prognostic humoral marker, especially in mild/moderately symptomatic and non-ischaemic CHF patients.

Transketolase from Cyanophora paradoxa: in vitro import into cyanelles and pea chloroplasts and a complex history of a gene often, but not always, transferred in the context of secondary endosymbiosis.

The glaucocystophyte Cyanophora paradoxa is an obligatorily photoautotrophic biflagellated protist containing cyanelles, peculiar plastids surrounded by a peptidoglycan layer between their inner and outer envelope membranes. Although the 136-kb cyanelle genome surpasses higher plant chloroplast genomes in coding capacity by about 50 protein genes, these primitive plastids still have to import >2,000 polypeptides across their unique organelle wall. One such protein is transketolase, an essential enzyme of the Calvin cycle. We report the sequence of the pre-transketolase cDNA from C. paradoxa and in vitro import experiments of precursor polypeptides into cyanelles and into pea chloroplasts. The transit sequence clearly indicates the localization of the gene product to cyanelles and is more similar to the transit sequences of the plant homologues than to transit sequences of other cyanelle precursor polypeptides with the exception of a cyanelle consensus sequence at the N-terminus. The mature sequence reveals conservation of the thiamine pyrophosphate binding site. A neighbor-net planar graph suggests that Cyanophora, higher plants, and the photosynthetic protist Euglena gracilis acquired their nuclear-encoded transketolase genes via endosymbiotic gene transfer from the cyanobacterial ancestor of plastids; in the case of Euglena probably entailing two transfers, once from the plastid in the green algal lineage and once again in the secondary endosymbiosis underlying the origin of Euglena's plastids. By contrast, transketolase genes in some eukaryotes with secondary plastids of red algal origin, such as Thalassiosira pseudonana, have retained the pre-existing transketolase gene germane to their secondary host.

Role for staphylococci in misguided thrombus resolution of chronic thromboembolic pulmonary hypertension.

OBJECTIVE: Acute pulmonary emboli usually resolve within 6 months. However, in 0.1% to 3.8% of cases thrombus transforms into fibrous masses. If vascular obstruction is severe, the resulting condition is chronic thromboembolic pulmonary hypertension (CTEPH). Patients who carry ventriculo-atrial (VA-) shunts for the treatment of hydrocephalus and report a history of shunt infection are at an increased risk for CTEPH. Because CTEPH lacks traditional plasmatic risk factors for venous thromboembolism, we hypothesized that delayed thrombus resolution rather than abnormal coagulation is important, and that bacterial infection would be important for this misguidance. METHODS AND RESULTS: Human CTEPH thromboemboli were harvested during pulmonary endarterectomy. The effects of Staphylococcal infection on thrombus organization were examined in a murine model of stagnant-flow venous thrombosis. Staphylococcal DNA, but not RNA, was detected in 6 of 7 thrombi from VA shunt carriers. In the mouse model, staphylococcal infection delayed thrombus resolution in parallel with upregulation of transforming growth factor (TGF) beta and connective tissue growth factor. CONCLUSIONS: In the present work, we propose a mechanism of disease demonstrating that infection with Staphylococci enhances fibrotic vascular remodeling after thrombosis, resulting in misguided thrombus resolution. Thrombus infection appears to be a trigger in the evolution of CTEPH.

Neutrophil extracellular traps and monocyte subsets at the culprit lesion site of myocardial infarction patients.

Neutrophils release their chromatin into the extracellular space upon activation. These web-like structures are called neutrophil extracellular traps (NETs) and have potent prothrombotic and proinflammatory properties. In ST-elevation myocardial infarction (STEMI), NETs correlate with increased infarct size. The interplay of neutrophils and monocytes impacts cardiac remodeling. Monocyte subsets are classified as classical, intermediate and non-classical monocytes. In the present study, in vitro stimulation with NETs led to an increase of intermediate monocytes and reduced expression of CX3CR1 in all subsets. Intermediate monocytes have been associated with poor outcome, while non-classical CX3CR1-positive monocytes could have reparative function after STEMI. We characterized monocyte subsets and NET markers at the culprit lesion site of STEMI patients (n = 91). NET surrogate markers were increased and correlated with larger infarct size and with fewer non-classical monocytes. Intermediate and especially non-classical monocytes were increased at the culprit site compared to the femoral site. Low CX3CR1 expression of monocytes correlated with high NET markers and increased infarct size. In this translational system, causality cannot be proven. However, our data suggest that NETs interfere with monocytic differentiation and receptor expression, presumably promoting a subset shift at the culprit lesion site. Reduced monocyte CX3CR1 expression may compromise myocardial salvage.

Predictors of outcome in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by intraluminal thrombus organization and fibrous obliteration of pulmonary arteries. Recently, associated medical conditions such as splenectomy, ventriculoatrial shunt for the treatment of hydrocephalus, permanent central intravenous lines, inflammatory bowel disease, and osteomyelitis were found to be associated with the development of CTEPH. The study aim was to define the impact of these novel risk factors on survival. METHODS AND RESULTS: Between January 1992 and December 2006, 181 patients diagnosed with CTEPH were tracked with the use of our center's customized computer database. A Cox regression model was used to examine relations between survival and associated medical conditions, age, sex, hemodynamic parameters, modified New York Heart Association functional class at diagnosis, CTEPH type, pulmonary endarterectomy, and anti-cardiolipin antibodies/lupus anticoagulant. During a median observation time of 22.1 (range, 0.03 to 152) months, the clinical end point of cardiovascular death or lung transplantation occurred in 48 cases (27%). Pulmonary endarterectomy (hazard ratio, 0.14; 95% CI, 0.05 to 0.41; P=0.0003), associated medical conditions (hazard ratio, 3.17; 95% CI, 1.70 to 5.92; P=0.0003), and pulmonary vascular resistance (hazard ratio, 1.02; 95% CI, 1.00 to 1.04; P=0.04) were predictors of survival. Thirty-day postoperative mortality (24% versus 9%) and the incidence of postoperative pulmonary hypertension (92% versus 20%) were substantially higher in patients with associated medical conditions. CONCLUSIONS: CTEPH-predisposing medical conditions, such as splenectomy, permanent central intravenous lines, and certain inflammatory disorders, predict poor survival in CTEPH.

Asymmetric dimethylarginine is increased in chronic thromboembolic pulmonary hypertension.

RATIONALE: Asymmetric dimethylarginine (ADMA), a potent endogenous nitric oxide synthase (NOS) inhibitor, is increased in idiopathic pulmonary arterial hypertension and associated with unfavorable outcome. OBJECTIVES: Chronic thromboembolic pulmonary hypertension (CTEPH), although principally amenable to surgical removal of major pulmonary arterial obstructions by pulmonary endarterectomy, may show a small-vessel pulmonary arteriopathy similar to idiopathic pulmonary arterial hypertension. We hypothesized that ADMA plasma levels are increased in patients with CTEPH. METHODS: We measured ADMA by high-performance liquid chromatography at the time of diagnosis in 135 patients with CTEPH. Inoperability in 66 patients was based on an imbalance between severity of pulmonary hypertension and morphologic lesions. MEASUREMENTS AND MAIN RESULTS: ADMA plasma levels were significantly elevated in patients, compared with 40 matched control subjects (0.62 [0.51-0.73] vs. 0.51 [0.45-0.6] micromol/L, P = 0.0002). At baseline, ADMA plasma concentrations correlated with mixed venous saturation (r = -0.25, P = 0.005), right atrial pressure (r = 0.35, P < 0.0001), and cardiac index (r = -0.21, P = 0.01). Patients who underwent surgery demonstrated lower ADMA levels at baseline than inoperable patients (0.60 [0.5-0.68] vs. 0.63 [0.53-0.85] micromol/L, P = 0.02), with a further decrease 12 +/- 1 months after pulmonary endarterectomy (P = 0.02). Endothelial NOS expression in endothelial cells was low in patients with elevated ADMA plasma levels. Survival of patients with ADMA plasma levels >/= 0.64 micromol/L was worse than in patients with ADMA plasma levels < 0.64 micromol/L. CONCLUSIONS: ADMA plasma levels correlate with the severity of pulmonary vascular disease and predict outcome in patients with CTEPH. Measurement of ADMA plasma levels may be useful for estimating the degree of small-vessel arteriopathy in CTEPH.

Usefulness of thrombosis and inflammation biomarkers in chronic thromboembolic pulmonary hypertension-sampling plasma and surgical specimens.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) results from persistent pulmonary vascular obstructions, presumably due to inflammatory thrombosis. Because estimates of thrombus volume at diagnosis have no predictive value, we investigated the role of the thrombosis marker, D-dimer, and the inflammation marker, C-reactive protein (CRP), for predicting outcomes in CTEPH. METHODS: A total 289 consecutive patients with CTEPH were followed for 57 (median 45 to 69) months. One hundred fifty-seven of these patients underwent surgical pulmonary endarterectomy (PEA). D-dimer and CRP were collected at the time of CTEPH diagnosis and their impact on outcome was analyzed using Cox and logistic regression models. Their association with thrombus composition was analyzed utilizing HistoQuest. RESULTS: D-dimer and CRP levels were separately and independently predictive of death or need for lung transplantation (p = 0.012 and p = 0.025, respectively). For example, 5-year survival was 90% (confidence limits 84% to 96%) in patients with D-dimer levels <0.5 µg/ml and CRP <1 mg/dl at diagnosis, as compared with 50% (36% to 64%) for patients with D-dimer ≥0.5 µg/ml and CRP ≥1 mg/dl (p < 0.001). D-dimer and CRP both decreased significantly after PEA (p < 0.01). The amount of fresh red thrombus in thrombendarterectomy specimens correlated positively with D-dimer levels at diagnosis (r = 0.37, p = 0.003). CONCLUSIONS: D-dimer and CRP at the time of diagnosis are independent and significant predictors of outcome in CTEPH, available at the time of diagnosis. This observation suggests an important role for fibrin turnover and inflammation in the pathogenesis of CTEPH and the associated complications.

Subcutaneous treprostinil in congenital heart disease-related pulmonary arterial hypertension.

OBJECTIVE: To assess the efficacy and safety of subcutaneous treprostinil in adult patients with congenital heart disease (CHD)-associated pulmonary arterial hypertension (PAH) after 12 months of treatment. METHODS: Consecutive adult patients with CHD-PAH received subcutaneous treprostinil to maximum tolerated doses in an observational study. RESULTS: Advanced CHD-PAH patients with WHO class III or IV disease (n=32, age 40±10 years, 20 females) received treprostinil for suboptimal response to bosentan (n=12), WHO functional class IV disease (FC, n=7) or prior to bosentan approval (n=13). In the multivariate mixed model, mean increase in 6 min walk distance (6-MWD) from baseline to 12 months was 114 m (76; 152) (P<0.001). WHO FC improved significantly (P=0.001) and B-type brain natriuretic peptide decreased from 1259 (375; 2368) pg/mL to 380 (144; 1468) pg/mL (P=0.02). In those 14 patients who had haemodynamic data before and after initiation of treprostinil, pulmonary vascular resistance decreased significantly (from 18.4±11.1 to 12.6±7.9 Wood units, P=0.003). The most common adverse events were infusion-site erythema and pain. One patient stopped treatment because of intolerable infusion-site pain after 8 months of treatment. No other major treatment-related complications were observed. Five patients died during early follow-up, having experienced a decrease in their 6-MWD prior. CONCLUSIONS: Subcutaneous treprostinil therapy is generally safe and effective for at least 12 months and may be used in CHD-related PAH class III and IV.

Active endothelin is an important vasoconstrictor in acute coronary thrombi.

Acute coronary syndrome is characterized by compromised blood flow at the epicardial and microvascular levels. We have previously shown that thrombectomy in ST-elevation myocardial infarction (STEMI) accelerates ST-segment resolution, possibly by preventing distal embolization. We hypothesized that thrombus constituents contribute to microcirculatory dysfunction. Therefore, we analyzed the molecular and cellular composition of acute coronary thrombi, and correlated vasoconstrictive mediators with the magnitude of ST-segment resolution within one hour of percutaneous coronary intervention (PCI). Fresh coronary thrombi were retrieved in 35 consecutive STEMI patients who were treated with the X-Sizer thrombectomy catheter, and thrombus cell counts and vasoconstrictor concentrations were assessed. Twelve-lead ECG recordings were analyzed prior to and one hour after PCI. Concentration of endothelin (ET) was 20.0 (7.9-52.2) fmol/ml in thrombus compared with 0.1 (0.1-0.3) fmol/ml in corresponding peripheral plasma (p < 0.0001), representing a selective 280 (70.0-510.0)-fold enrichment, exceeding enrichment of noradrenaline, angiotensin II and serotonin. Human coronary thrombus homogenates exerted vasoconstriction of porcine coronary artery rings that was inhibited by the dual ET receptor blocker tezosentan. Extracted ET (r = 0.523 p = 0.026) and number of leukocytes (r = 0.555 p = 0.017) were correlated with the magnitude of ST-segment resolution. In conclusion, the amount of active ET and white blood cells aspirated from STEMI target vessels correlated with improvement of territorial microcirculatory function as illustrated by enhanced ST-segment resolution.

Hemodynamic Thresholds for Precapillary Pulmonary Hypertension.

BACKGROUND: Hemodynamic differentiation between pulmonary arterial hypertension (PAH) and postcapillary pulmonary hypertension (PH) is important because treatment options are strikingly different for the two disease subsets. Whereas patients with PAH can be treated effectively with targeted therapies, their use in postcapillary PH is currently not recommended. Our aim was to establish an algorithm to identify patients who are likely to experience a significant hemodynamic treatment response. METHODS: We determined hemodynamic cutoffs to discriminate between idiopathic PAH and postcapillary PH in a large database of 4,363 stable patients undergoing first diagnostic right and left heart catheterizations. In a second step, we performed a patient-level pooled analysis of four randomized, placebo-controlled trials including 541 patients with PAH who received treprostinil or placebo, to validate hemodynamic cutoffs with regard to treatment response. RESULTS: Receiver operating characteristic analysis identified mean pulmonary arterial wedge pressure (mPAWP) < 12 mm Hg and diastolic pulmonary vascular pressure gradient (DPG) ≥ 7 mm Hg as the best hemodynamic discriminators between idiopathic PAH and postcapillary PH. In our treatment study, only patients with mPAWP < 12 mm Hg, DPG > 20 mm Hg or a combination of both had a significant placebo-corrected improvement in hemodynamics. CONCLUSIONS: mPAWP < 12 mm Hg and DPG > 20 mm Hg identify patients with PAH who are likely to have significant hemodynamic improvement with prostacyclin treatment.