Von Willebrand factor as a biological sensor of blood flow to monitor percutaneous aortic valve interventions.

RATIONALE: Percutaneous aortic valve procedures are a major breakthrough in the management of patients with aortic stenosis. Residual gradient and residual aortic regurgitation are major predictors of midterm and long-term outcome after percutaneous aortic valve procedures. We hypothesized that (1) induction/recovery of high molecular weight (HMW) multimers of von Willebrand factor defect could be instantaneous after acute changes in blood flow, (2) a bedside point-of-care assay (platelet function analyzer-closure time adenine DI-phosphate [PFA-CADP]), reflecting HMW multimers changes, could be used to monitor in real-time percutaneous aortic valve procedures. OBJECTIVE: To investigate the time course of HMW multimers changes in models and patients with instantaneous induction/reversal of pathological high shear and its related bedside assessment. METHODS AND RESULTS: We investigated the time course of the induction/recovery of HMW multimers defects under instantaneous changes in shear stress in an aortic stenosis rabbit model and in patients undergoing implantation of a continuous flow left ventricular assist device. We further investigated the recovery of HMW multimers and monitored these changes with PFA-CADP in aortic stenosis patients undergoing transcatheter aortic valve implantation or balloon valvuloplasty. Experiments in the aortic stenosis rabbit model and in left ventricular assist device patients demonstrated that induction/recovery of HMW multimers occurs within 5 minutes. Transcatheter aortic valve implantation patients experienced an acute decrease in shear stress and a recovery of HMW multimers within minutes of implantation which was sustained overtime. In patients with residual high shear or with residual aortic regurgitation, no recovery of HMW multimers was observed. PFA-CADP profiles mimicked HMW multimers recovery both in transcatheter aortic valve implantation patients without aortic regurgitation (correction) and transcatheter aortic valve implantation patients with aortic regurgitation or balloon valvuloplasty patients (no correction). CONCLUSIONS: These results demonstrate that variations in von Willebrand factor multimeric pattern are highly dynamic, occurring within minutes after changes in blood flow. It also demonstrates that PFA-CADP can evaluate in real time the results of transcatheter aortic valve procedures.

Liver X receptor activation stimulates iron export in human alternative macrophages.

RATIONALE: In atherosclerotic plaques, iron preferentially accumulates in macrophages where it can exert pro-oxidant activities. OBJECTIVE: The objective of this study was, first, to better characterize the iron distribution and metabolism in macrophage subpopulations in human atherosclerotic plaques and, second, to determine whether iron homeostasis is under the control of nuclear receptors, such as the liver X receptors (LXRs). METHODS AND RESULTS: Here we report that iron depots accumulate in human atherosclerotic plaque areas enriched in CD68 and mannose receptor (MR)-positive (CD68(+)MR(+)) alternative M2 macrophages. In vitro IL-4 polarization of human monocytes into M2 macrophages also resulted in a gene expression profile and phenotype favoring iron accumulation. However, M2 macrophages on iron exposure acquire a phenotype favoring iron release, through a strong increase in ferroportin expression, illustrated by a more avid oxidation of extracellular low-density lipoprotein by iron-loaded M2 macrophages. In line, in human atherosclerotic plaques, CD68(+)MR(+) macrophages accumulate oxidized lipids, which activate LXRα and LXRß, resulting in the induction of ABCA1, ABCG1, and apolipoprotein E expression. Moreover, in iron-loaded M2 macrophages, LXR activation induces nuclear factor erythroid 2-like 2 expression, thereby increasing ferroportin expression, which, together with a decrease of hepcidin mRNA levels, promotes iron export. CONCLUSIONS: These data identify a role for M2 macrophages in iron handling, a process regulated by LXR activation.

Identification of additional proteins in differential proteomics using protein interaction networks.

In this study, we developed a novel computational approach based on protein-protein interaction networks to identify a list of proteins that might have remained undetected in differential proteomic profiling experiments. We tested our computational approach on two sets of human smooth muscle cell protein extracts that were affected differently by DNase I treatment. Differential proteomic analysis by saturation DIGE resulted in the identification of 41 human proteins. The application of our approach to these 41 input proteins consisted of four steps: (i) Compilation of a human protein-protein interaction network from public databases; (ii) calculation of interaction scores based on functional similarity; (iii) determination of a set of candidate proteins that are needed to efficiently and confidently connect the 41 input proteins; and (iv) ranking of the resulting 25 candidate proteins. Two of the three highest-ranked proteins, beta-arrestin 1, and beta-arrestin 2, were experimentally tested, revealing that their abundance levels in human smooth muscle cell samples were indeed affected by DNase I treatment. These proteins had not been detected during the experimental proteomic analysis. Our study suggests that our computational approach may represent a simple, universal, and cost-effective means to identify additional proteins that remain elusive for current 2D gel-based proteomic profiling techniques.

Human atherosclerotic plaque alternative macrophages display low cholesterol handling but high phagocytosis because of distinct activities of the PPARγ and LXRα pathways.

RATIONALE: A crucial step in atherogenesis is the infiltration of the subendothelial space of large arteries by monocytes where they differentiate into macrophages and transform into lipid-loaded foam cells. Macrophages are heterogeneous cells that adapt their response to environmental cytokines. Th1 cytokines promote monocyte differentiation into M1 macrophages, whereas Th2 cytokines trigger an "alternative" M2 phenotype. OBJECTIVE: We previously reported the presence of CD68(+) mannose receptor (MR)(+) M2 macrophages in human atherosclerotic plaques. However, the function of these plaque CD68(+)MR(+) macrophages is still unknown. METHODS AND RESULTS: Histological analysis revealed that CD68(+)MR(+) macrophages locate far from the lipid core of the plaque and contain smaller lipid droplets compared to CD68(+)MR(-) macrophages. Interleukin (IL)-4-polarized CD68(+)MR(+) macrophages display a reduced capacity to handle and efflux cellular cholesterol because of low expression levels of the nuclear receptor liver x receptor (LXR)α and its target genes, ABCA1 and apolipoprotein E, attributable to the high 15-lipoxygenase activity in CD68(+)MR(+) macrophages. By contrast, CD68(+)MR(+) macrophages highly express opsonins and receptors involved in phagocytosis, resulting in high phagocytic activity. In M2 macrophages, peroxisome proliferator-activated receptor (PPAR)γ activation enhances the phagocytic but not the cholesterol trafficking pathways. CONCLUSIONS: These data identify a distinct macrophage subpopulation with a low susceptibility to become foam cells but high phagocytic activity resulting from different regulatory activities of the PPARγ-LXRα pathways.

Aldosterone, mortality, and acute ischaemic events in coronary artery disease patients outside the setting of acute myocardial infarction or heart failure.

BACKGROUND: Recent studies have demonstrated that aldosterone levels measured in patients with heart failure or acute myocardial infarction (MI) are associated with long-term mortality, but the association with aldosterone levels in patients with coronary artery disease (CAD) outside these specific settings remains unknown. In addition, no clear mechanism has been elucidated to explain these observations. The present study was designed to evaluate the relationship between the level of aldosterone and the risk of death and acute ischaemic events in CAD patients with a preserved left ventricular (LV) function and no acute MI. METHODS AND RESULTS: In 799 consecutive CAD patients referred for elective coronary angioplasty measurements were obtained before the procedure for: aldosterone (median = 25 pg/mL), brain natriuretic peptide (BNP) (median = 35 pg/mL), hsC-reactive protein (median = 4.17 mg/L), and left ventricular ejection fraction (mean = 58%). Patients with acute MI or coronary syndrome (ACS) who required urgent revascularization were not included in the study. The primary endpoint, cardiovascular death, occurred in 41 patients during a median follow-up period of 14.9 months. Secondary endpoints-total mortality, acute ischaemic events (acute MI or ischaemic stroke), and the composite of death and acute ischaemic events-were observed in 52, 54, and 94 patients, respectively. Plasma aldosterone was found to be related to BMI, hypertension and NYHA class, and inversely related to age, creatinine clearance, and use of beta-blockers. Multivariate Cox model analysis demonstrated that aldosterone was independently associated with cardiovascular mortality (P = 0.001), total mortality (P = 0.001), acute ischaemic events (P = 0.01), and the composite of death and acute ischaemic events (P = 0.004). Reclassification analysis, using integrated discrimination improvement (IDI) and net reclassification improvement (NRI), demonstrated incremental predictive value of aldosterone (P < 0.0001). CONCLUSION: Our results demonstrate that, in patients with CAD but without heart failure or acute MI, the level of aldosterone is strongly and independently associated with mortality and the occurrence of acute ischaemic events.

PPARgamma activation primes human monocytes into alternative M2 macrophages with anti-inflammatory properties.

Th1 cytokines promote monocyte differentiation into proatherogenic M1 macrophages, while Th2 cytokines lead to an "alternative" anti-inflammatory M2 macrophage phenotype. Here we show that in human atherosclerotic lesions, the expression of M2 markers and PPARgamma, a nuclear receptor controlling macrophage inflammation, correlate positively. Moreover, PPARgamma activation primes primary human monocytes into M2 differentiation, resulting in a more pronounced anti-inflammatory activity in M1 macrophages. However, PPARgamma activation does not influence M2 marker expression in resting or M1 macrophages, nor does PPARgamma agonist treatment influence the expression of M2 markers in atherosclerotic lesions, indicating that only native monocytes can be primed by PPARgamma activation to an enhanced M2 phenotype. Furthermore, PPARgamma activation significantly increases expression of the M2 marker MR in circulating peripheral blood mononuclear cells. These data demonstrate that PPARgamma activation skews human monocytes toward an anti-inflammatory M2 phenotype.

Prognostic value of hemoglobin decline over the GRACE score in patients hospitalized for an acute coronary syndrome.

In this work, we analyzed the prognostic significance of changes in hemoglobin during intensive care unit (ICU) stay in patients with acute coronary syndromes (ACS). We prospectively enrolled 591 patients (62 ± 14 years old, 73% male, 48% ST elevated myocardial infarction) free of blood cell transfusion or bleeding events. Changes in hemoglobin between admission and ICU discharge were obtained. The primary endpoint was death or hospitalization for MI within 6 months. Hemoglobin decreased from 13.65 ± 1.77 to 13.17 ± 1.74 g/dl, p < 0.0001 in the whole population. The end point was reached in 43 patients at a mean follow-up of 180 (range 2-180 days). A decrease in hemoglobin ≥0.9 g/dl (32% of the population) was associated with adverse clinical outcomes (HR 2.37, 95% CI (1.30-4.35), p = 0.005, respectively). In multivariate analysis, age >77 year-old (p = 0.0016), Killip class ≥2 (p = 0.009), anemia (p = 0.0064), decreased estimated glomerular filtration rate (p = 0.003), and hemoglobin decline ≥0.9 g/dl (p < 0.0001) were independently associated with outcome. Hemoglobin decline and anemia both provided additional prognostic information on top of the GRACE score, as demonstrated by a systematic improvement in model global fit, discrimination, and calibration. Hemoglobin decline is frequent during ICU stay in non-bleeding ACS patients. A decline in hemoglobin ≥0.9 g/dl identifies high-risk patients. Identification of these patients refines the prognostic value of the GRACE score.

Measuring and targeting aldosterone and renin in atherosclerosis-a review of clinical data.

Our understanding of the development and progression of atherosclerosis has increased substantially over the past decades. A significant role for the renin-angiotensin-aldosterone system (RAAS) in this process has gained appreciation in recent years. Preclinical and clinical studies have associated components of the RAAS with various cardiovascular disease conditions. Classically known for its contribution to hypertension, dysregulation of the system is now also believed to promote vascular inflammation, fibrosis, remodeling, and endothelial dysfunction, all intimately related to atherosclerosis. The reduction in cardiovascular mortality and morbidity, as seen with the use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, supports the concept that RAAS is involved in the pathogenesis of atherosclerotic disease. However, the underlying molecular mechanisms of the pathophysiology remain to be completely understood. Evidence points toward additional benefit from therapeutic approaches aiming at more complete inhibition of the system and the possible utility of renin or aldosterone in the prediction of cardiovascular outcome. This review will summarize the current knowledge from clinical studies regarding the presumptive role of renin and aldosterone in the prediction and management of patients with atherosclerosis. For this purpose, a literature search was performed, focusing on available clinical data regarding renin or aldosterone and cardiovascular outcome.

Renal resistance index and its prognostic significance in patients with heart failure with preserved ejection fraction.

BACKGROUND: Functional renal impairment is a common feature of heart failure with preserved ejection fraction (HFpEF). The link between functional renal impairment and HFpEF remains incompletely understood. With hypertension and diabetes as frequent co-morbidities, patients with HFpEF are at risk of developing intra-renal vascular hemodynamic alterations that may lead to functional renal impairment and impact on prognosis. METHODS: Renal resistive index (RRI) was non-invasively determined by Doppler ultrasonic examination in 90 HFpEF patients and 90 age- and sex-matched hypertensive patients without evidence of heart failure (HF) who served as controls. Clinical, laboratory and cardiac echocardiography data were obtained in HFpEF patients and controls. To investigate its possible clinical relevance, RRI was evaluated as a prognostic index of all-cause mortality and hospitalization for HF. RESULTS: Mean RRI was substantially greater in HFpEF patients than in controls (P < 0.0001), while mean blood pressure, glomerular filtration rate, hemoglobin and serum protein levels were significantly lower in HFpEF patients than in controls. On multivariable analysis, mean RRI was independently associated with HFpEF. In addition, increased mean RRI was an independent predictor of poor outcome [hazard ratio = 1.06 95% confidence interval (1.01-1.10), P = 0.007] and remained significantly associated with the outcome after adjustment for univariate predictors that included low mean blood pressure, low hemoglobin concentration and low glomerular filtration rate. Conclusion. Patients with HFpEF exhibit intra-renal vascular hemodynamic alterations. The severity of intra-renal vascular hemodynamic alterations correlates with a poor outcome.

High-dose tranexamic acid reduces blood loss in postpartum haemorrhage.

INTRODUCTION: Our purpose in conducting this study was to determine whether administration of high-dose tranexamic acid (TA) at the time of diagnosis of postpartum haemorrhage (PPH) could reduce blood loss. METHODS: This was a randomised, controlled, multicentred, open-label trial. Women with PPH >800 mL following vaginal delivery were randomly assigned to receive TA (loading dose 4 g over 1 hour, then infusion of 1 g/hour over 6 hours) or not. In both groups, packed red blood cells (PRBCs) and colloids could be used according to French guidelines. The use of additional procoagulant treatments was permitted only in cases involving intractable bleeding. The primary objective was to assess the efficacy of TA in the reduction of blood loss in women with PPH, and the secondary objectives were the effect of TA on PPH duration, anaemia, transfusion and the need for invasive procedures. RESULTS: A total of 144 women fully completed the protocol (72 in each group). Blood loss between enrolment and 6 hours later was significantly lower in the TA group than in the control group (median, 173 mL; first to third quartiles, 59 to 377) than in controls (221 mL; first to third quartiles 105 to 564) (P = 0.041). In the TA group, bleeding duration was shorter and progression to severe PPH and PRBC transfusion was less frequent than in controls (P < 0.03). Invasive procedures were performed in four women in the TA group and in seven controls (P = NS). PPH stopped after only uterotonics and PRBC transfusion in 93% of women in the TA group versus 79% of controls (P = 0.016). Mild, transient adverse manifestations occurred more often in the TA group than in the control group (P = 0.03). CONCLUSIONS: This study is the first to demonstrate that high-dose TA can reduce blood loss and maternal morbidity in women with PPH. Although the study was not adequately powered to address safety issues, the observed side effects were mild and transient. A larger international study is needed to investigate whether TA can decrease the need for invasive procedures and reduce maternal morbidity in women with PPH. TRIAL REGISTRATION: Controlled Trials ISRCTN09968140.

Clinical and echocardiographic correlates of plasma B-type natriuretic peptide levels in patients with aortic valve stenosis and normal left ventricular ejection fraction.

BACKGROUND: Several studies suggest that BNP testing may help define the timing of aortic valve surgery in patients with aortic valve stenosis (AVS) prior onset of overt LV systolic dysfunction. The aim of this study was to identify clinical and echocardiographic correlates of plasma BNP levels in a large cohort of patients with AVS and preserved LV ejection fraction. METHOD AND RESULTS: One hundred thirty-five consecutive patients were prospectively included in the present study (Mean age 73 ± 13 years old, 66 (49%) male). Eighty-nine patients (66%) had severe AVS (aortic valve area <0.6 cm(2) /m(2) BSA). Plasma BNP levels, clinical and comprehensive Doppler echocardiography evaluation was performed in all patients. Independent clinical correlates of plasma BNP levels (R(2) = 0.19) were older age (P < 0.0001) and presence of AVS symptoms (P = 0.004). Independent echocardiographic correlates of plasma BNP levels (R(2) = 0.38) were E/Ea ratio (P = 0.01), LV mass index (P = 0.018), left atrial surface (P < 0.0001) and systolic pulmonary artery pressure (sPAP; P = 0.004). Overall, independent correlates of plasma BNP levels (R(2) = 0.47) were older age (P = 0.001), known coronary artery disease (P = 0.047), increased LV mass index (P = 0.001), left atrial enlargement (P = 0.002), and increased sPAP (P = 0.003). CONCLUSIONS: In patients with AVS and normal LV ejection fraction, plasma BNP predominantly reflects the clinical and echocardiographic consequences of afterload burden imposed on the left ventricle rather than the severity of valve stenosis, per se.

Inferior vena cava agenesis and deep vein thrombosis: 10 patients and review of the literature.

Inferior vena cava agenesis (IVCA) is a rare condition, found in almost 5% of patients under 30 years old with unprovoked deep venous thrombosis (DVT). We describe 10 consecutive patients with IVCA-associated DVT and conducted an extensive literature review to investigate the typical spectrum of IVCA-associated DVT. Among our patients (eight men and two women; mean age, 25 ± 4.5 years), DVT followed intense and unusual (major) physical activity for eight of them. DVT was bilateral in six patients and unilateral in four. Ultrasonography was unable to detect IVCA, which was visualized by computed-tomography scans for seven patients, and magnetic resonance imaging and angiography for 10. Hereditary thrombophilia screening, to detect factor V Leiden or prothrombin gene heterozygosity (G20210A mutation), was positive for only two patients. Wearing elastic stockings and taking an indefinite or long-term vitamin K antagonist were prescribed for all 10 patients and nine complied with the latter. To date, 62 patients with IVCA-associated DVT have been reported in the English literature. Analysis of them and our patients yielded a typical spectrum of IVCA-associated DVT characteristics: IVCA occurs in young adults, particularly males, and is revealed by proximal DVT following major physical exertion. All were treated with a prolonged vitamin K antagonist and advised to wear elastic stockings. No precise duration of anticoagulation has been established.

Metabolic syndrome and collateral vessel formation in patients with documented occluded coronary arteries: association with hyperglycaemia, insulin-resistance, adiponectin and plasminogen activator inhibitor-1.

AIMS: The metabolic syndrome (MS) is associated with an increased cardiovascular risk. Patients with the MS have endothelial dysfunction, decreased circulating adiponectin, and a high expression of angiogenic inhibitors such as plasminogen activator inhibitor-1 (PAI-1). We hypothesized that such patients, in the event of a coronary occlusion, might exhibit a less developed collateral circulation. METHODS AND RESULTS: Three hundred and eighty-seven consecutive patients with at least one coronary occlusion of a major coronary vessel at diagnostic angiography were prospectively enrolled. Collateral development was graded with validated angiographic methods. The MS was defined according to the ATP-III definition. Fasting glucose, adiponectin, insulin concentrations, and PAI-1 were measured at the time of angiography. MS was associated with less developed collateral vessels (P = 0.005). In multivariable analysis adjusting for potential confounding factors including the duration of coronary occlusion (P = 0.0001), fasting glycaemia (P = 0.0007), low adiponectin concentration (P = 0.01), insulin-resistance (HOMA-IR; P = 0.01), high circulating PAI-1 concentration (P = 0.01), and hypertension (P = 0.008) were independently associated with poor coronary collateral vessel development. CONCLUSION: This study shows that in patients with coronary occlusion, collateral circulation is impaired in patients with the MS. This association is partly related to fasting glycaemia and to key parameters linked to insulin resistance.

Functional impairment of von Willebrand factor in hypertrophic cardiomyopathy: relation to rest and exercise obstruction.

BACKGROUND: Hypertrophic obstructive cardiomyopathy submits blood to conditions of high shear stress. High shear stress impairs von Willebrand factor (VWF) and promotes abnormal bleeding in aortic stenosis. We sought to evaluate VWF impairment and its relationships to baseline or exercise obstruction in hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: Outflow obstruction was evaluated by rest and exercise echocardiography in 62 patients with HCM (age 44+/-16 years, 40 males). HCM was considered obstructive in 28 patients with rest or exercise peak gradient >or=30 mm Hg. Blood was sampled to assess VWF. History of bleeding was recorded. Baseline median (25th to 75th percentile) peak gradient was 11 (5-62) mm Hg. Shear-induced platelet adhesion was impaired in patients with obstructive HCM. The ratio of VWF-collagen-binding activity to antigen and the percentage of high-molecular-weight multimers of VWF were lower in patients with obstructive HCM than in those with nonobstructive HCM (0.49 [0.43 to 0.59] versus 0.82 [0.73 to 1.03] and 5.0% [3.9% to 7.2%] versus 11.7% [10.8% to 12.5%], respectively; both P<0.0001). Platelet adhesion time, VWF-collagen-binding activity-to-antigen ratio, and the percentage of high-molecular-weight multimers correlated closely and independently with peak gradient (r=0.81, r=-0.68, and r=-0.89, respectively; all P<0.0001). According to receiver operating characteristic curves, a peak gradient threshold of 15 mm Hg at rest and 35 mm Hg during exercise was sufficient to impair VWF. Conversely, VWF function tended to improve with a decrease in peak gradient. Obstructive HCM patients had a trend toward abnormal spontaneous bleeding. CONCLUSIONS: In obstructive HCM, VWF impairment is frequent and is closely and independently related to the magnitude of outflow obstruction. A resting peak gradient of 15 mm Hg is sufficient to impair VWF. VWF abnormalities might favor abnormal bleeding in this setting.

Unlike PPARgamma, PPARalpha or PPARbeta/delta activation does not promote human monocyte differentiation toward alternative macrophages.

Macrophages adapt their response to micro-environmental signals. While Th1 cytokines promote pro-inflammatory M1 macrophages, Th2 cytokines promote an "alternative" anti-inflammatory M2 macrophage phenotype. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors expressed in macrophages where they control the inflammatory response. It has been shown that PPARgamma promotes the differentiation of monocytes into anti-inflammatory M2 macrophages in humans and mice, while a role for PPARbeta/delta in this process has been reported only in mice and no data are available for PPARalpha. Here, we show that in contrast to PPARgamma, expression of PPARalpha and PPARbeta/delta overall does not correlate with the expression of M2 markers in human atherosclerotic lesions, whereas a positive correlation with genes of lipid metabolism exists. Moreover, unlike PPARgamma, PPARalpha or PPARbeta/delta activation does not influence human monocyte differentiation into M2 macrophages in vitro. Thus, PPARalpha and PPARbeta/delta do not appear to modulate the alternative differentiation of human macrophages.

Inhibition of tissue factor-factor VIIa proteolytic activity blunts hepatic metastasis in colorectal cancer.

BACKGROUND: Expression of the principal initiator of coagulation, tissue factor (TF), by colorectal cancer (CRC) cells is involved in tumoral angiogenesis and metastasis progression, after binding of factor VIIa (FVIIa) to TF and generation of TF-FVIIa activity. We thus hypothesized that inhibition of the TF pathway by active site-blocked FVIIa (FFR-FVIIa) may prevent the development of hepatic metastasis in CRC. METHODS: Rat tumoral cells (DHDK12 proB cells) expressing high levels of TF were injected in the portal vein in syngenic BDIX rats. Rats received intraperitoneal injection of either FFR-FVIIa, from d 3 to d 7 (adjuvant treatment) (n = 19), or solvent buffer (n = 18) (control group). Additionally, cancer cells were infused subcutaneously in 20 other rats, which were assigned to FFR-FVIIa adjuvant treatment (n = 10), or buffer treatment (n = 10). Macroscopic and histological analysis was performed at d 14. RESULTS: In the control group, infusion of cancer cells resulted in development of macroscopic hepatic tumors in 17/18 rats. In the adjuvant FFR-FVIIa group, macroscopic hepatic tumors were visible on the liver surface in 3/19 rats (P = 0.002 versus control). All rats with subcutaneous injection of proB cells exhibited macroscopic tumors, with no significant difference between the control and the treated ones. CONCLUSION: Inhibition of the proteolytic activity of TF-FVIIa complex blunted hematogenous hepatic metastasis, suggesting that TF-FVIIa is a relevant target for the prevention of hepatic metastasis in CRC. TF-blocking agents should be investigated as adjuvant treatment in this setting.

Exercise does not enhance the prognostic value of Doppler echocardiography in patients with left ventricular systolic dysfunction and functional mitral regurgitation at rest.

BACKGROUND: Functional mitral regurgitation (MR) is a powerful predictor of poor prognosis in patients with chronic heart failure (CHF) due to left ventricular systolic dysfunction (LVSD). However, severity of MR varies with dynamic exercise. Accordingly, we sought to assess the prognostic value of exercise-induced changes in functional MR in patients with LVSD and functional MR at rest. METHODS: One hundred four patients with chronic heart failure due to LVSD (ejection fraction [EF] < 45%) and functional MR at rest underwent conventional continuous 2-dimensional Doppler echocardiography at rest and during maximal symptom-limited exercise. The primary end point of the study was all-cause mortality. The median follow-up period was 20 months. RESULTS: Fifty-six patients (54%) had ischemic cardiomyopathy. When feasible, all 56 patients with ischemic cardiomyopathy had undergone revascularization procedures before enrollment into the study. In the whole patient cohort, resting LV end-diastolic volume was 205 +/- 76 mL and EF was 26% +/- 9%. Univariate predictors of death were functional class (New York Heart Association), LV EF, LV end-diastolic volume, resting mitral effective regurgitant orifice, mitral E deceleration time, tricuspid annular plane systolic excursion < or = 14 mm, systolic blood pressure, LV EF, and trans-tricuspid pressure gradient response to exercise. Exercise-induced change in mitral effective regurgitant orifice did not predict survival (HR 0.99, 95% CI 0.94-1.04, P = .63). By Cox multivariate analysis, resting LV end-diastolic volume and tricuspid annular plane systolic excursion < or = 14 mm were the independent predictors of death. CONCLUSIONS: Exercise Doppler echocardiography does not refine the predictive value of resting Doppler echocardiography in patients with LVSD and functional MR at rest.

Left ventricular abnormal response during dynamic exercise in patients with heart failure and preserved left ventricular ejection fraction at rest.

BACKGROUND: The mechanisms that contribute to limit functional capacity are incompletely understood in patients with preserved resting ejection fraction (HFpREF). We assessed left ventricular (LV) systolic response to dynamic exercise in patients with HFpREF and in patients with similar comorbidities to HFpREF patients but without history or evidence of heart failure. METHODS AND RESULTS: Twenty-five HFpREF patients in steady-state clinical condition without significant coronary artery disease and 25 hypertensive controls underwent exercise echocardiography. At rest, systolic pulmonary artery pressure, left atrial area, E/A and E/e' ratios were greater in patients with HFpREF than in control patients, whereas peak systolic mitral annular velocity was lower in HFpREF patients. The exercise-induced changes in LVEF, forward stroke volume, and cardiac output were significantly lower in HFpREF compared with control patients (-4 +/- 8 vs. +6 +/- 6 %, P = .001; -4 +/- 9 vs. +10 +/- 10 mL, P < .0001, and 1.6 +/- 1.2 vs. 3.5 +/- 1.8 L/min, P < .0001, respectively). Exercise-induced changes in effective arterial elastance significantly differed in HFpREF and control patients (0.5 +/- 0.6 vs. -0.2 +/- 0.5 mm Hg/mL, P < .0001). In addition, 7 of the 25 HFpREF patients developed functional mitral regurgitation during exercise and none in controls. CONCLUSIONS: When compared with patients with similar comorbidities but without history or evidence of heart failure, patients with HFpREF experience greater arterial stiffening and thereby a deterioration of global LV systolic performance during dynamic exercise.

Acquired von Willebrand syndrome in aortic stenosis.

BACKGROUND: Aortic-valve stenosis can be complicated by bleeding that is associated with acquired type 2A von Willebrand syndrome. However, the prevalence and cause of the hemostatic abnormality in aortic stenosis are unknown. METHODS: We enrolled 50 consecutive patients with aortic stenosis, who completed a standardized screening questionnaire to detect a history of bleeding. Forty-two patients with severe aortic stenosis underwent valve replacement. Platelet function under conditions of high shear stress, von Willebrand factor collagen-binding activity and antigen levels, and the multimeric structure of von Willebrand factor were assessed at base line and one day, seven days, and six months postoperatively. RESULTS: Skin or mucosal bleeding occurred in 21 percent of the patients with severe aortic stenosis. Platelet-function abnormalities under conditions of high shear stress, decreased von Willebrand factor collagen-binding activity and the loss of the largest multimers, or a combination of these was present in 67 to 92 percent of patients with severe aortic stenosis and correlated significantly with the severity of valve stenosis. Primary hemostatic abnormalities were completely corrected on the first day after surgery but tended to recur at six months, especially when there was a mismatch between patient and prosthesis (with an effective orifice area of less than 0.8 cm2 per square meter of body-surface area). CONCLUSIONS: Type 2A von Willebrand syndrome is common in patients with severe aortic stenosis. Von Willebrand factor abnormalities are directly related to the severity of aortic stenosis and are improved by valve replacement in the absence of mismatch between patient and prosthesis.