Maria Paola Buzzi

Plasma Levels of Soluble Receptor for Advanced Glycation End Products and Coronary Artery Disease in Nondiabetic Men

Objective—The receptor for advanced glycation end products (RAGE) is a cell surface receptor whose signaling pathway has been implicated in atherogenesis. RAGE has an endogenous secretory receptor form, called soluble RAGE (sRAGE), that could exert antiatherogenic effects by acting as a decoy. We sought to determine whether a decreased plasma level of sRAGE could be independently associated with the prevalence of coronary artery disease (CAD) in nondiabetic men. Methods and Results—Plasma levels of sRAGE were determined in 328 nondiabetic male patients with angiographically proved CAD and in 328 age-matched healthy controls. The concentration of sRAGE in plasma was significantly lower (P<0.0001) in CAD cases [median (interquartile range): 966 (658–1372) pg/mL] than in control subjects [1335 (936–1954) pg/mL]. In logistic regression analysis, the multivariate-adjusted odds ratio for the presence of CAD was 6.719 (95% confidence interval, 3.773 to 11.964; P<0.0001) when the lowest quartile of the sRAGE level was compared with the highest quartile. Conclusions—Our findings indicate that low levels of sRAGE in plasma are independently associated with the presence of CAD in nondiabetic men and suggest that sRAGE is one of the clinically important molecules associated with atherosclerosis.

Decreased plasma levels of soluble receptor for advanced glycation end-products in patients with essential hypertension

Objectives Advanced glycation end-products (AGE) may cause vascular stiffening by forming crosslinks through the collagen molecule or by interaction with their cellular transductional receptor (RAGE). A secreted isoform of RAGE, termed soluble RAGE (sRAGE), may contribute to the removal/detoxification of AGE by acting as a decoy. Here we studied the plasma sRAGE levels in hypertensive and normotensive human subjects. We also investigated the relationship between blood pressure parameters and plasma sRAGE concentrations. Design A cross-sectional case–control study. Setting and participants The outpatient clinic of a university teaching hospital. Participants were 147 never-treated patients with essential hypertension (87 men and 60 women, aged 50 ± 10 years) and 177 normotensive controls (118 men and 59 women, aged 49 ± 10 years). Main outcome measures Plasma sRAGE levels determined by enzyme-linked immunosorbent assay, systolic blood pressure (SBP), diastolic blood pressure, pulse pressure (PP) and mean arterial pressure. Results The plasma concentration of sRAGE [median (interquartile range)] was 1206 (879–1658) pg/ml in hypertensive subjects and 1359 (999–2198) pg/ml in normotensive controls (P = 0.002). Simple correlation analysis revealed that log-transformed sRAGE levels were inversely correlated with SBP (r = −0.11; P < 0.001) and PP (r = −0.23; P < 0.001). Forward-selection multiple regression analysis revealed that log-transformed sRAGE levels were determined more strongly by PP (F = 3.127, P < 0.001). Conclusions Plasma sRAGE levels are decreased in patients with essential hypertension and are inversely related to PP. Our results raise the possibility that sRAGE may play a role in arterial stiffening and its complications.

Rapid Heart Rate Increase at Onset of Exercise Predicts Adverse Cardiac Events in Patients With Coronary Artery Disease

Background—We previously demonstrated that reduced vagal activity and/or increased sympathetic activity identify post–myocardial infarction patients at high risk for cardiac mortality. Simple and inexpensive autonomic markers are necessary to perform autonomic screening in large populations. We tested our hypothesis that abnormally elevated heart rate (HR) responses at the onset of an exercise stress test, which imply rapid vagal withdrawal immediately preceding sympathetic activation, might predict adverse cardiac events in patients with documented coronary artery disease. Methods and Results—The HR increase during the first minute (&Dgr;HR1 minute) of a symptom-limited exercise stress test was quantified in 458 patients with documented coronary artery disease. During a 6-year (interquartile range 3.7 to 9.0 years) follow-up, 71 patients experienced adverse cardiac events (21 cardiac deaths, 56 nonfatal myocardial infarctions). In univariate analysis, &Dgr;HR1 minute ≥12 bpm (above the median value of its distribution) predicted both adverse outcome and cardiac death with a hazard ratio of 5.0 (95% CI 2.7 to 9.1; P<0.0001) and of 15.6 (95% CI 2.0 to 118.7; P<0.001), respectively. After adjustment for potential confounders, &Dgr;HR1 minute remained predictive for both combined end points and for cardiac death. Conclusions—A marked HR increase at the onset of a standard exercise stress test is a novel and easily available parameter that could be clinically useful as an independent predictor of adverse cardiac events, including death, among patients with documented coronary artery disease.

The 374T/A RAGE Polymorphism Protects Against Future Cardiac Events in Nondiabetic Patients with Coronary Artery Disease

BACKGROUND The -374T/A polymorphism of the Receptor for Advanced Glycation End products (RAGE) may exert a protective effect toward the development of atherosclerosis. No data are currently available on the potential prognostic role of this polymorphism in patients with angiographically proven coronary artery disease (CAD). Hereto we sought to address this issue in a large consecutive cohort of patients undergoing coronary revascularization. METHODS A total of 643 CAD patients who underwent myocardial revascularization were followed for 4.2 years (interquartile range: 2.2-8.1 years). The rates of major cardiac adverse events (death, nonfatal myocardial infarction, and unstable angina) were compared according to the -374T/A RAGE polymorphism. RESULTS During a median follow-up period of 4.2 years, the study endpoint was reached by 126/643 patients (19.6%). We observed adverse cardiac events in 13.4% of patients with AA, 17.5% of those with AT, and 24.2% of those with TT genotype (p <0.05). In univariate Cox proportional hazard analysis, the AA genotype was significantly related to a better outcome in nondiabetic patients (hazard ratio: 0.47, 95% CI: 0.20-0.96; p <0.05). No association was found with adverse events in diabetic subjects. After allowance for potential confounders, the AA genotype remained a significant prognostic factor in the nondiabetic group (adjusted HR: 0.41, 95% CI: 0.17-0.94, p <0.05). CONCLUSIONS The -374T/A RAGE polymorphism is an independent protective factor for cardiac events in nondiabetic patients with CAD. The effect of this genetic variant seems to be attenuated in diabetics, who have chronic RAGE upregulation.

Apelin plasma levels predict arrhythmia recurrence in patients with persistent atrial fibrillation.

Low levels of the regulatory peptide apelin have been reported in patients with lone atrial fibrillation (AF). We evaluate the potential utility of assessing apelin plasma levels as a predictor of AF recurrence in individuals presenting for electrical cardioversion. Plasma levels of apelin, brain natriuretic peptide (BNP) and high-sensitivity C-reactive protein were measured in 93 patients, with persistent AF before successful external electrical cardioversion. Significantly lower apelin plasma levels were found in patients with AF recurrence as respect to population with persistence of sinus rhythm during a six months follow-up. The hazard increased with duration of AF, left atrial dimension, BNP concentrations. Subjects with apelin levels below the median had a hazard ratio of 3.1 of arrhythmia recurrence with respect to those with high apelin levels (p< 0.05). A significant difference in BNP levels was found between patients with and without AF recurrence during the follow-up. After adjusting for potential confounders, both BNP and apelin retained their statistical significance as independent predictors of arrhythmia recurrence. Patients with both low apelin and elevated BNP had a worse prognosis compared with those with either low apelin or elevated BNP alone. Low plasma apelin levels before external electrical cardioversion are an independent prognostic factor for arrhythmia recurrence in patients with AF treated with antiarrhythmic drugs. Apelin may be of particular value for the identification of high-risk patients in addition to BNP.

Markers of eosinophilic inflammation and risk prediction in patients with coronary artery disease

Background  The eotaxin family comprises three distinct peptides (eotaxin, eotaxin‐2 and eotaxin‐3) which have been implicated in eosinophilic inflammation. In vitro and clinical studies suggest that eotaxins could play a role in vascular inflammation, but no data are available on their prognostic significance in patients with angiographically documented coronary artery disease (CAD).

Age of Onset of Myocardial Infarction: Is Promoter Polymorphism of the RAGE Gene Implicated?

Receptor for advanced glycation endproducts (RAGE) is a cell-surface molecule member of the immunoglobulin superfamily and engages differing ligands relevant to distinct processes. A growing body of evidence has suggested that RAGE may promote vascular inflammation through several mechanisms. The objective of this study was to identify the possible relationship between the -374 T/A polymorphism of the RAGE gene, myocardial infarction (MI), and its age of onset. A total of 691 MI patients and 234 matched controls were investigated. In this study, the frequency of the A allele and AA genotype of the -374 T/A promoter polymorphism is significantly lower in patients with MI respect to the control group (p < 0.01). Our results showed a significant role of the AA genotype on age of onset of MI. In particular, the mean age of the first MI was higher in patients with the AA genotype as compared to those that were AT or TT genotype carriers (p = 0.002). The relationship between -374 T/A RAGE polymorphism and age for the appearance of MI was independently related to common risk factors of disease (p < 0.01). Kaplan-Meier curves confirmed that subjects with the AA genotype have a later development of MI (p = 0.0022). This study is the first to investigate the role of RAGE polymorphisms on the susceptibility to develop the acute coronary events in the Italian population and identified this polymorphism as an age-related factor for MI development. The homozygous AA genotype may exert a protective role against the early development of MI.

The -374T/A variant of the rage gene promoter is associated with clinical restenosis after coronary stent placement.

Upregulation of the receptor for advanced glycation end products (RAGE) may play a crucial role in neointimal formation upon vessel injury. The −374T/A variant of the RAGE gene promoter, which has been associated with an altered expression of the cell-surface receptor, could exert a protective effect toward the development of vascular disease. The aim of this study is to determine the impact of this common genetic variant in the occurrence of clinical in-stent restenosis after coronary stent implantation. The −374T/A polymorphism of the RAGE gene promoter was evaluated by PCR-RFLPs in 267 patients with coronary artery disease who underwent coronary stent implantation and a subsequent coronary angiography 6–9 months later for suspected restenosis. In-stent restenosis was assessed by means of quantitative angiography. Carriers of the-374AA genotype showed a significantly reduced risk of developing restenosis after percutaneous transluminal intervention than non-carriers. To determine whether the protective effect of the homozygous AA genotype toward clinical restenosis was independent of potential confounders, we performed multivariable logistic regression analysis. After allowance for clinical and biochemical risk factors and stent length, the AA genotype remained significantly associated with a reduced prevalence of in-stent restenosis. No relation was evident between the RAGE genotype and established cardiovascular risk factors. In conclusion, the −374AA genotype of the RAGE gene promoter could be associated with a reduced risk of in-stent restenosis after coronary stent implantation.

APJ polymorphisms in coronary artery disease patients with and without hypertension

Apelin is an endogenous peptide that increases cardiac inotropism through its APJ receptor. Certain findings indicate that the apelinergic system may have a pathophysiological role in cardiovascular disease and there is evidence showing the role of the apelinergic system in blood pressure regulation in vitro and in animal models. The role of the apelin-APJ system in cardiovascular physiology and its interaction with other neuroendocrine pathways has not been fully elucidated. However, the small number of reported studies indicates that apelin signaling may be involved in the regulation of blood pressure, cardiac contractile function, fluid balance, angiogenesis and inhibition of apoptosis. We evaluated the possible relationship between the G212A and A445C APJ polymorphisms and coronary artery disease (CAD) in Italian patients and in healthy controls by RFLP-PCR. We analyzed the allelic and genotypic frequencies of APJ polymorphisms in 664 patients (378 with hypertension) and 143 controls. There were no differences between allelic and genotypic frequencies in patients in respect to the controls for both polymorphisms analyzed. In the CAD population, there was an increased frequency of the G212 allele in patients with hypertension in respect to patients without hypertension. No differences were present in the two subgroups for the A445C polymorphism. Although the functional role of the G212A polymorphism has not yet been identified, it is possible to hypothesize that the presence of the A allele may cause a gain in function of the apelin/APJ system associated with a lower risk of hypertension.

Microalbuminuria and sRAGE in High-Risk Hypertensive Patients Treated with Nifedipine/Telmisartan Combination Treatment: A Substudy of TALENT

Some antihypertensive drugs have also renoprotective and anti-inflammatory properties that go beyond their effect on blood pressure. It has been suggested that microalbuminuria and glomerular filtration rate (GFR) are associated with circulating levels of the soluble form of the receptor, sRAGE (soluble receptor for advanced glycation ends-products). In the present analysis, we used data from the TALENT study to evaluate soluble receptor for advanced glycation end-products (sRAGE) plasma levels in patients with hypertension and high-cardiovascular risk-treated nifedipine and telmisartan in combination. Treatment with nifedipine-telmisartan significantly decreased mean systolic and diastolic ambulatory blood pressure and resulted in a significant increase in sRAGE plasma concentrations after 24 weeks of therapy. We concluded that in hypertensive patients with early-stage renal disease, sRAGE concentrations are not influenced by either microalbuminuria or GFR. Long-term treatment with a combination of nifedipine-telmisartan may have a beneficial effect increasing sRAGE plasma levels, thus exerting an atheroprotective and anti-inflammatory activity.