Patrick Rossignol

Involvement of the Mural Thrombus as a Site of Protease Release and Activation in Human Aortic Aneurysms

Acquired abdominal aortic aneurysms are usually associated with a mural thrombus through which blood continues to flow. Some early data suggest that aneurysmal evolution correlates with the biological activity of the thrombus. Our hypothesis was therefore that the thrombus could adsorb blood components and store, release, and participate in the activation of proteases involved in aneurysmal evolution. For this purpose, we have explored both the metalloproteinase and fibrinolytic systems in the thrombus and the wall of human aneurysms. We have first investigated blood clot formation and lysis in vitro. Spontaneous clotting induces a release of promatrix metalloproteinase (pro-MMP)-9 into the serum that was fourfold higher than in paired control plasma (P < 0.001). Fibrinolysis progressively released more MMP-9 in a time-dependent manner (P < 0.01). After selective isolation, we demonstrated that polymorphonuclear leukocytes are the main source of MMP-9 release during clot formation. Protease content was then analyzed in 35 mural thrombi and walls of human abdominal aortic aneurysms sampled during surgical repair. In 15 aneurysms, the liquid phase at the interface between the thrombus and the wall was sampled separately. Both thrombus and wall contained MMP-2 and MMP-9 but the ratio MMP-9/MMP-2 was higher in the thrombus than in the wall. The liquid interface also contained active MMP-9. Immunohistochemistry of the thrombus confirmed these findings, showing the presence of polymorphonuclear leukocytes at the luminal pole of the thrombus, co-localizing with MMP-9 storage. In contrast, MMP-3 and MMP-7 were only present in the aneurysmal wall. Plasminogen was present in the mural thrombus but plasmin activity was present in both thrombus and wall. In the liquid interface, plasmin-alpha(2)-anti-plasmin complexes were detected demonstrating in vivo the activation of plasminogen. In contrast, u-PA and t-PA were detectable only in the wall, suggesting that plasminogen present in the thrombus could be activated by factors secreted by the arterial wall. This was demonstrated in vitro, in which co-incubation of thrombus and wall extracts generated plasmin in the presence of a fibrin matrix and activated MMPs. In conclusion, our study strongly suggests that the mural thrombus, by trapping polymorphonuclear leukocytes and adsorbing plasma components could act as a source of proteases in aneurysms that may play a critical role in enlargement and rupture.

Extracellular Cardiac Matrix Biomarkers in Patients With Acute Myocardial Infarction Complicated by Left Ventricular Dysfunction and Heart Failure Insights From the Eplerenone Post–Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) Study

Background— Aldosterone stimulates cardiac collagen synthesis. Circulating biomarkers of collagen turnover provide a useful tool for the assessment of cardiac remodeling in patients with congestive heart failure and left ventricular systolic dysfunction after acute myocardial infarction. Methods and Results— In a substudy of the Eplerenone Post–Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS), which evaluated the effects of the selective aldosterone receptor antagonist eplerenone versus placebo, serum levels of collagen biomarkers were measured in 476 patients with congestive heart failure after acute myocardial infarction complicated with left ventricular systolic dysfunction. The combination of the type I collagen telopeptide and brain natriuretic peptide levels above median at baseline was associated with all-cause mortality and the composite end point of cardiovascular death or heart failure hospitalization, with hazard ratios of 2.49 (P=0.039) and 3.03 (P=0.002), respectively. During follow-up, levels of aminoterminal propeptide of type I and type III procollagen were found to be consistently lower in the eplerenone group and significantly lower beginning at 6 months. Conclusions— Changes in biomarkers of collagen synthesis and degradation suggest that extracellular matrix remodeling is an active process in patients with congestive heart failure and left ventricular systolic dysfunction after acute myocardial infarction. High type I collagen telopeptide and high brain natriuretic peptide serum levels are associated with the highest event rate. Eplerenone suppresses post–acute myocardial infarction collagen turnover changes.

Vascular structure and function is correlated to cognitive performance and white matter hyperintensities in older hypertensive patients with subjective memory complaints.

Background and Purpose— Arterial stiffening and thickening and endothelial dysfunction may be associated with cognitive decline or white matter hyperintensities (WMH) independently of blood pressure level. We aimed to investigate, using an integrative approach, the relative contributions of structural and functional vascular factors to the degree of cognitive impairment (primary outcome) and the severity of WMH (secondary outcome) in elderly hypertensive patients with subjective memory complaints, a group prone to dementia. Methods— A prospective, dedicated, cross-sectional population of 198 elderly hypertensive patients (mean age 69.3±6.2 years) with subjective memory complaints underwent a full set of cognitive function assessments, brain MRI with semiquantification of WMH, carotid ultrasonography, carotid–femoral pulse wave velocity, brachial endothelial function, and plasma von Willebrand Factor measurements. Results— After adjustment for the usual cardiovascular risk factors, increased arterial stiffness (as assessed by pulse wave velocity) was significantly and independently associated with memory impairment in men. The severity of WMH was independently associated with increased carotid intima media thickness and stiffness (as assessed by augmentation index) as well as with increased age and plasma levels of von Willebrand Factor, a biomarker of endothelial dysfunction. Conclusions— Our data suggest that vascular abnormalities, independently of blood pressure levels, may play a role in the setting of subjective memory complaints as well as of WMH in elderly hypertensive patients. Arterial thickness and stiffness as well as endothelial function should be assessed simultaneously and may represent additional targets for the prevention of subjective memory complaints and WMH.

Galectin-3 Mediates Aldosterone-Induced Vascular Fibrosis

Objective—Aldosterone (Aldo) is involved in arterial stiffness and heart failure, but the mechanisms have remained unclear. Galectin-3 (Gal-3), a &bgr;-galactoside-binding lectin, plays an important role in inflammation, fibrosis, and heart failure. We investigated here whether Gal-3 is involved in Aldo-induced vascular fibrosis. Methods and Results—In rat vascular smooth muscle cells Gal-3 overexpression enhanced specifically collagen type I synthesis. Moreover Gal-3 inhibition by modified citrus pectin or small interfering RNA blocked Aldo-induced collagen type I synthesis. Rats were treated with Aldo-salt combined with spironolactone or modified citrus pectin for 3 weeks. Hypertensive Aldo-treated rats presented vascular hypertrophy, inflammation, fibrosis, and increased aortic Gal-3 expression. Spironolactone or modified citrus pectin treatment reversed all the above effects. Wild-type and Gal-3 knock-out mice were treated with Aldo for 6 hours or 3 weeks. Aldo increased aortic Gal-3 expression, inflammation, and collagen type I in wild-type mice at both the short- and the long-term, whereas no changes occurred in Gal-3 knock-out mice. Conclusion—Our data indicate that Gal-3 is required for inflammatory and fibrotic responses to Aldo in vascular smooth muscle cells in vitro and in vivo, suggesting a key role for Gal-3 in vascular fibrosis.

Epidemiology, contributors to, and clinical trials of mortality risk in chronic kidney failure

Patients with chronic kidney failure--defined as a glomerular filtration rate persistently below 15 mL/min per 1·73 m(2)--have an unacceptably high mortality rate. In developing countries, mortality results primarily from an absence of access to renal replacement therapy. Additionally, cardiovascular and non-cardiovascular mortality are several times higher in patients on dialysis or post-renal transplantation than in the general population. Mortality of patients on renal replacement therapy is affected by a combination of socioeconomic factors, pre-existing medical disorders, renal replacement treatment modalities, and kidney failure itself. Characterisation of the key pathophysiological contributors to increased mortality and cardiorenal risk staging systems are needed for the rational design of clinical trials aimed at decreasing mortality. Policy changes to improve access to renal replacement therapy should be combined with research into low-cost renal replacement therapy and optimum clinical care, which should include multifaceted approaches simultaneously targeting several of the putative contributors to increased mortality.

Association of galectin-3 and fibrosis markers with long-term cardiovascular outcomes in patients with heart failure, left ventricular dysfunction, and dyssynchrony: insights from the CARE-HF (Cardiac Resynchronization in Heart Failure) trial

Circulating biomarkers of collagen turnover reflect extracellular cardiac matrix (ECCM) remodelling. The extent to which the success of cardiac resynchronization therapy (CRT) is influenced by the degree of cardiac fibrosis and whether CRT can influence matrix remodelling has yet to be studied. Our aim was to determine, in patients with heart failure (HF) and cardiac dyssynchrony, whether ECCM biomarkers are influenced by CRT and can predict cardiovascular outcomes and response to CRT.

Influence of baseline and worsening renal function on efficacy of spironolactone in patients With severe heart failure: insights from RALES (Randomized Aldactone Evaluation Study).

OBJECTIVES This study investigated the influence of baseline and worsening renal function (WRF) on the efficacy of spironolactone in patients with severe heart failure (HF). BACKGROUND Renal dysfunction or decline in renal function is a known predictor of adverse outcome in patients with HF, and treatment decisions are often on the basis of measures of renal function. METHODS We used data from the RALES (Randomized Aldactone Evaluation Study) in 1,658 patients with New York Heart Association functional class III or IV HF and an ejection fraction <35%. Participants were randomized to spironolactone 25 mg, which could be titrated to 50 mg, or placebo daily. Renal function (estimated glomerular filtration rate [eGFR]) was estimated by the Modification of Diet in Renal Disease equation. Worsening renal function was defined as a 30% reduction in eGFR from baseline to 12 weeks post-randomization. RESULTS Individuals with reduced baseline eGFR exhibited similar relative risk reductions in all-cause death and the combined endpoint of death or hospital stays for HF as those with a baseline eGFR >60 ml/min/1.73 m(2) and greater absolute risk reduction compared with those with a higher baseline eGFR (10.3% vs. 6.4%). Moreover, WRF (17% vs. 7% for spironolactone and placebo groups, p < 0.001) was associated with an increased adjusted risk of death in the placebo group (hazard ratio: 1.9, 95% confidence interval: 1.3 to 2.6) but not in those randomized to spironolactone (hazard ratio: 1.1, 95% confidence interval: 0.79 to 1.5, p interaction = 0.009). The risk of hyperkalemia and renal failure was higher in those with worse baseline renal function and those with WRF, particularly in the spironolactone arm, but the substantial net benefit of spironolactone therapy remained. CONCLUSIONS The absolute benefit of spironolactone was greatest in patients with reduced eGFR. Worsening renal function was associated with a negative prognosis, yet the mortality benefit of spironolactone was maintained.

Safety and Efficacy of Eplerenone in Patients at High Risk for Hyperkalemia and/or Worsening Renal Function : Analyses of the EMPHASIS-HF Study Subgroups (Eplerenone in Mild Patients Hospitalization And SurvIval Study in Heart Failure)

OBJECTIVES The study sought to investigate the safety and efficacy of eplerenone in patients at high risk for hyperkalemia or worsening renal function (WRF) in EMPHASIS-HF, a trial that enrolled patients at least 55 years old with heart failure and reduced ejection fraction (HF-REF), in New York Heart Association (NYHA) functional class II and with an estimated glomerular filtration rate (eGFR) >30 ml/min/1.73 m(2) and serum potassium <5.0 mmol/l. Patients were receiving optimal therapy and most had been hospitalized for a cardiovascular reason within 180 days of inclusion. BACKGROUND Underuse of eplerenone in patients with HF-REF may be due to fear of inducing hyperkalemia or WRF in high-risk patients. METHODS This was a pre-specified analysis of subgroups of patients at high risk of hyperkalemia or WRF (patients ≥ 75 years of age, with diabetes, with eGFR <60 ml/min/1.73 m(2), and with systolic blood pressure < median of 123 mm Hg), examining the major safety measures (potassium >5.5, >6.0, and <3.5 mmol/l; hyperkalemia leading to study-drug discontinuation or hospitalization; and hospitalization for WRF) as well as the primary outcome (hospitalization for HF or cardiovascular mortality). RESULTS In all high-risk subgroups, patients treated with eplerenone had an increased risk of potassium >5.5 mmol/l but not of potassium >6.0 mmol/l, and of hospitalization for hyperkalemia or discontinuation of study medication due to adverse events. Eplerenone was effective in reducing the primary composite endpoint in all subgroups. CONCLUSIONS In patients with chronic HF-REF, in NYHA functional class II, and meeting specific inclusion and exclusion criteria, including an eGFR >30 ml/min/1.73 m(2) and potassium <5.0 mmol/l, eplerenone was both efficacious and safe when carefully monitored, even in subgroups at high risk of developing hyperkalemia or WRF. (A Comparison Of Outcomes In Patients In New York Heart Association [NYHA] Class II Heart Failure When Treated With Eplerenone Or Placebo In Addition To Standard Heart Failure Medicines [EMPHASIS-HF Study]; NCT00232180).

Mineralocorticoid receptor antagonists for heart failure with reduced ejection fraction: Integrating evidence into clinical practice

Mineralocorticoid receptor antagonists (MRAs) improve survival and reduce morbidity in patients with heart failure, reduced ejection fraction (HF-REF), and mild-to-severe symptoms, and in patients with left ventricular systolic dysfunction and heart failure after acute myocardial infarction. These clinical benefits are observed in addition to those of angiotensin converting enzyme inhibitors or angiotensin receptor blockers and beta-blockers. The morbidity and mortality benefits of MRAs may be mediated by several proposed actions, including antifibrotic mechanisms that slow heart failure progression, prevent or reverse cardiac remodelling, or reduce arrhythmogenesis. Both eplerenone and spironolactone have demonstrated survival benefits in individual clinical trials. Pharmacologic differences exist between the drugs, which may be relevant for therapeutic decision making in individual patients. Although serious hyperkalaemia events were reported in the major MRA clinical trials, these risks can be mitigated through appropriate patient selection, dose selection, patient education, monitoring, and follow-up. When used appropriately, MRAs significantly improve outcomes across the spectrum of patients with HF-REF.

Eplerenone survival benefits in heart failure patients post-myocardial infarction are independent from its diuretic and potassium-sparing effects. Insights from an EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study) substudy.

OBJECTIVES The purpose of this study was to determine whether a diuretic effect may be detectable in patients treated with eplerenone, a mineralocorticoid receptor antagonist, as compared with placebo during the first month of EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival study) (n = 6,080) and whether this was associated with eplerenones beneficial effects on cardiovascular outcomes. BACKGROUND The mechanism of the survival benefit of eplerenone in patients with heart failure post-myocardial infarction remains uncertain. METHODS A diuretic effect was indirectly estimated by changes at 1 month that was superior to the median changes in the placebo group in body weight (-0.05 kg) and in the estimated plasma volume reduction (+1.4%). A potassium-sparing effect was defined as a serum potassium increase greater than the median change in the placebo group: +0.11 mmol/l. RESULTS In the eplerenone group, body weight (p < 0.0001) and plasma volume (p = 0.047) decreased, whereas blood protein and serum potassium increased (both, p < 0.0001), as compared with the placebo group, suggesting a diuretic effect induced by eplerenone, associated with a potassium-sparing effect. A diuretic effect, as defined by an estimated plasma volume reduction, was independently associated with 11% to 19% better outcomes (lower all-cause death, cardiovascular death or cardiovascular hospitalization, all-cause death or hospitalization, hospitalization for heart failure). Potassium sparing was also independently associated with 12% to 34% better outcomes. There was no statistically significant interaction between the observed beneficial effects of eplerenone (9% to 17%) on cardiovascular outcomes and potassium-sparing or diuretic effects. CONCLUSIONS Eplerenones beneficial effects on long-term survival and cardiovascular outcomes are independent from early potassium-sparing or diuretic effects, suggesting that mineralocorticoid receptor antagonism provides cardiovascular protection beyond its diuretic and potassium-sparing properties.