Routine laboratory tests to risk-stratify patients with chronic coronary artery disease.

BACKGROUND: Several biohumoral variables, taken individually, are predictors of prognosis in patients with chronic coronary artery disease (CAD). We hypothesized that taken together, laboratory tests provide prognostic information that is additive to a complete diagnostic work-up. METHODS: We prospectively examined 2370 consecutive patients with chronic CAD, as shown by a >50% coronary stenosis (in 95% of patients), previous coronary revascularization (in 31% of patients), and/or previous myocardial infarction (MI, in 54% of patients). We tested the ability of laboratory and clinical variables to predict future cardiac events (cardiac death and non-fatal MI). RESULTS: During follow-up (median, 46 months), 147 patients (6.2%) died from cardiac causes and 81 (3.4%) experienced a non-fatal MI. Using multivariate analysis, after adjustment for clinical variables (including left ventricular ejection fraction and angiographic extent of coronary stenoses), a high-density lipoprotein cholesterol (HDLc) concentration<35 mg/dL (p<0.0001), a neutrophil-to-lymphocyte ratio >2.4 (p=0.0014), and an fT3 serum level<2.1 pg/mL with normal thyrotropin (low-T3 syndrome) (p=0.0260) showed an independent and incremental prognostic value, and were associated with an increase in the rate of cardiac events of 86%, 57% and 41%, respectively. When these variables were added to clinical and instrumental variables, the prognostic power of the model increased significantly (global chi-square improvement: from 157.01 to 185.07, p<0.0001). CONCLUSION: Low HDLc, high neutrophil-to-lymphocyte ratio and low-T3 syndrome, both individually and taken together, provide prognostic information that is independent of and incremental to the main clinical and instrumental findings.

Inverse association between circulating levels of soluble receptor for advanced glycation end-products and coronary plaque burden.

AIM: Low levels of soluble receptor for advanced glycation end-products (sRAGE) have been reported to be associated with coronary artery disease (CAD) and peripheral atherosclerosis. This study explored the relationship between circulating levels of sRAGE and the characteristics of coronary vessels detected by 64-slice computed tomography angiography (CTA). METHODS: In this cross-sectional study we included 127 consecutive patients with CAD but without acute coronary syndrome. Quantitative volumetric analysis of the lumen and plaque burden of the vessel wall (soft and calcific components) was performed for the three major coronary vessels. Each component was expressed as a percentage of vessel volume and utilized in per-patient analysis. The patients were classified into two groups according to the presence of calcium volume: non-calcified plaque (NCP) group (calcium volume %=0) and calcified plaque (CP) group (calcium volume % >0). RESULTS: In the NCP group, but not in the CP group, simple regression analysis revealed a negative association of total plaque burden % with sRAGE (ß=-0.378, p=0.0019) and HDL cholesterol (ß=-0.368, p=0.003) and a positive association with creatinine (ß=0.258, p=0.041) and male gender (ß=0.317, p=0.01). After adjusting for confounding factors, the total plaque burden % remained significantly associated only with sRAGE (ß=-0.358, p=0.011). CONCLUSIONS: Circulating sRAGE levels are associated in an inverse manner with non-calcified plaque burden, suggesting that it may be related with early atherosclerosis and plaque progression.

Soluble receptor for advanced glycation end products in COPD: relationship with emphysema and chronic cor pulmonale: a case-control study.

BACKGROUND: The receptor for advanced glycation end products (RAGE) is a multiligand signal transduction receptor that can initiate and perpetuate inflammation. Its soluble isoform (sRAGE) acts as a decoy receptor for RAGE ligands, and is thought to afford protection against inflammation. With the present study, we aimed at determining whether circulating sRAGE is correlated with emphysema and chronic cor pulmonale in chronic obstructive pulmonary disease (COPD). METHODS: In 200 COPD patients and 201 age- and sex-matched controls, we measured lung function by spirometry, and sRAGE by ELISA method. We also measured the plasma levels of two RAGE ligands, N-epsilon-carboxymethyl lysine and S100A12, by ELISA method. In the COPD patients, we assessed the prevalence and severity of emphysema by computed tomography (CT), and the prevalence of chronic cor pulmonale by echocardiography. Multiple quantile regression was used to assess the effects of emphysema, chronic cor pulmonale, smoking history, and comorbid conditions on the three quartiles of sRAGE. RESULTS: sRAGE was significantly lower (p = 0.007) in COPD patients (median 652 pg/mL, interquartile range 484 to 1076 pg/mL) than in controls (median 869 pg/mL, interquartile range 601 to 1240 pg/mL), and was correlated with the severity of emphysema (p < 0.001), the lower the level of sRAGE the greater the degree of emphysema on CT. The relationship remained statistically significant after adjusting for smoking history and comorbid conditions. In addition, sRAGE was significantly lower in COPD patients with chronic cor pulmonale than in those without (p = 0.002). Such difference remained statistically significant after adjusting for smoking history, comorbidities, and emphysema severity. There was no significant difference in the plasma levels of the two RAGE ligands between cases and controls. CONCLUSIONS: sRAGE is significantly lower in patients with COPD than in age- and sex-matched individuals without airflow obstruction. Emphysema and chronic cor pulmonale are independent predictors of reduced sRAGE in COPD.

Prognostic value of C-reactive protein in chronic obstructive pulmonary disease.

To establish whether C-reactive protein (CRP) is an independent predictor of all-cause mortality and hospitalization in chronic obstructive pulmonary disease (COPD), we followed 200 patients with COPD and 201 age- and gender -matched controls for a median time of 4.2 years (range, 0.2-5.1 years). Airflow obstruction was rated moderate if forced expiratory volume in one second (FEV(1)) was 50-69% of the predicted value, or severe if FEV(1) was <50%. The CRP level was categorized as low (≤3 mg/L) or high (>3 mg/L). The hazard of death was estimated by a proportional hazard regression model, using controls with low CRP as the reference category. Fifty subjects died: 41 (21%) among the COPD and 9 (4%) among the controls (p < 0.0001). The hazard of death in moderate COPD was not significantly higher than in the reference category, independently of the CRP level. In severe COPD with a low CRP, the hazard of death is 3.4 times higher than in the reference category (p = 0.008); in severe COPD and a high CRP it is 9.6 times higher (p < 0.0001). The rate of hospitalization in COPD patients with a high CRP is 1.9 times higher than in those with a low CRP [95% confidence interval (CI), 1.2-3.2]. In severe COPD, it is 6.9 times higher than in moderate COPD (95% CI, 3.8-12.7). A high CRP level is a significant amplifier of the risk of death only in severe COPD. The degree of airflow obstruction is a strong independent predictor of COPD-related outcomes.

Plasma N-epsilon-(carboxymethyl)lysine levels are associated with the extent of vessel injury after coronary arterial stenting.

OBJECTIVE: In animal models, increased tissue receptor for advanced glycation end products and its ligands, including N-epsilon-(carboxymethyl)lysine (CML), are critically implicated in postprocedural intimal hyperplasia after balloon injury. In patients undergoing percutaneous coronary interventions with stenting, we investigated whether plasma levels of CML and the soluble form of receptor for advanced glycation end products (sRAGE) changed during poststenting follow-up. METHODS: We studied 81 patients with coronary artery disease who underwent successful percutaneous coronary interventions. Plasma levels of CML and sRAGE were measured before intervention, and at 1 day and 180 days of follow-up. RESULTS: CML levels increased significantly at day 1 after stenting and persisted at an elevated level at 180 days (P=0.013), whereas sRAGE levels increased significantly at 180 days (P=0.011). CML levels were significantly higher in multivessel-treated patients than in single-vessel-treated patients both at 1 day and 180 days of follow-up. In addition, CML values were positively associated with the extent of stent area at 1 day and 180 days of follow-up (r=0.278, P=0.022 and r=0.315, P=0.012, respectively). In logistic regression analysis, only the extent of stent area predicted adverse clinical events at 180-day follow-up (P=0.03, odds ratio=14.25, confidence interval=1.25-162.2). CONCLUSION: This study supports the hypothesis that increased circulating levels of CML occurred in the presence of vascular injury. This persistent rise of CML could amplify an inflammatory phenomenon triggered by stent placement and thus contributes to coronary artery disease progression.

Predictive value of elevated neutrophil-lymphocyte ratio on cardiac mortality in patients with stable coronary artery disease.

BACKGROUND: An association between white blood cell count (WBC), severity of coronary artery disease (CAD) and survival has been described in patients with acute coronary syndrome. Our aim was to analyze the predictive ability for cardiac events of differential WBC, which is still not well characterized, against established risk factors in angiographically proven CAD patients. METHODS: We prospectively evaluated complete blood count, biomarkers of inflammation [(C-reactive protein (CRP) and serum iron (SI)], glucose/lipid metabolism [(fasting glucose (FG), total, high-density lipoprotein (HDL) and low-density lipoprotein cholesterol] and established risk factors in 422 consecutive ischemic patients with angiographically documented stable CAD. On a 3-year follow-up, cardiac death and non-fatal myocardial infarction (MI) were considered as end-points. RESULTS: At multivariate analysis neutrophil to lymphocyte ratio (N/L) emerged as independent predictor of cardiac death (HR 8.13; p=0.02) together with CRP, left ventricular ejection fraction (LVEF), FG, HDL and SI. CRP, LVEF, and HDL showed an independent prognostic value for cardiac death and non-fatal MI. Event-free survival according to N/L tertiles was 99% for the first tertile (1.23+/-0.26), 96.5% for the second (2.05+/-0.29), and 88.8% for the third one (5.19+/-3.81). CONCLUSIONS: N/L is an independent predictor of cardiac mortality in stable CAD patients.

Usefulness of high-sensitivity IL-6 measurement for clinical characterization of patients with coronary artery disease.

Interleukin 6 (IL-6) may represent an early marker of inflammatory activation and may be useful to ameliorate risk stratification in patients with ischemic heart disease. The aim of this study was to verify the performance characteristics of an ultrasensitive immunoassay (Biosource International, Camarillo, CA) for high-sensitivity (hs)-IL-6 measurement in comparison with hs-R&D Systems (Abingdon, United Kingdom) and Immulite System (Diagnostic Products Corporation [DPC], Los Angeles, CA) methods in patients with ischemic heart disease. In addition, hs-C-reactive protein (hs-CRP) concentrations were measured, to evaluate the correlation with hs-IL-6 levels. We measured IL-6 and CRP serum levels in 39 patients with ischemic heart disease and in 12 controls. Out of the 39 patients studied, 13 were affected by unstable angina, 13 by post-acute myocardial infarction (AMI) unstable angina, and 13 by stable angina. The imprecision profile and functional sensitivity were performed measuring 9 different serum pools in 10 runs. The Biosource method had the best performance characteristics as compared to the others. Mean IL-6 level was higher in patients with unstable and post-AMI unstable angina with respect to controls. CRP levels were elevated in patients with post-AMI. In the whole population a high significant linear regression was observed between Biosource hs-IL-6 and hs-CRP serum levels. The Biosource method for IL-6 measurement is characterized by a high functional sensitivity that allows a better stratification of patients with ischemic heart disease.

Short-term prevention of thromboembolic complications in patients with atrial fibrillation with aspirin plus clopidogrel: the Clopidogrel-Aspirin Atrial Fibrillation (CLAAF) pilot study.

BACKGROUND: We evaluated the short-term safety and efficacy of aspirin-plus-clopidogrel as antithrombotic therapy in nonvalvular atrial fibrillation (AF). METHODS AND RESULTS: Thirty patients (11 women, 45 to 75 years of age) with non-high-risk permanent (n = 12) or persistent AF awaiting cardioversion (n = 18) underwent transesophageal echocardiography to exclude left heart thrombi and were then randomly assigned to receive warfarin (international normalized ratio, 2 to 3 for 3 weeks) or aspirin (100 mg/d alone for 1 week)-plus-clopidogrel (75 mg/d added to aspirin for 3 weeks). Bleeding time and serum thromboxane B2 were measured at entry and at 3 weeks. Bleeding time, not affected by warfarin, was prolonged by 71% by aspirin (P <.05) and further, by 144%, by adding clopidogrel (P <.01 vs aspirin alone; +319%, P <.01, vs baseline). Thromboxane B2, not affected by warfarin, was reduced by aspirin (-98%, P <.01) but not further by clopidogrel. No thrombi or dense spontaneous echo-contrast were found at the 3-week transesophageal echocardiography. Seven of 9 patients receiving warfarin and 7 of 9 patients receiving aspirin-plus-clopidogrel, undergoing electrical cardioversion, achieved sinus rhythm. No thromboembolic or hemorrhagic events occurred in both arms throughout the 3-week treatment and a further 3-month follow-up. CONCLUSIONS: Aspirin-plus-clopidogrel and warfarin were equally safe and effective in preventing thromboembolism in this small group of patients with non-high-risk AF.

Genetic polymorphisms in folate and homocysteine metabolism as risk factors for DNA damage.

Epidemiological studies indicated a role for polymorphisms in genes of folate and homocysteine (Hcy) metabolism in the etiology of neurodegenerative disease, congenital defects and coronary artery disease (CAD). This study investigated the effect of several polymorphisms [C677 T, A1298C of methylenetetrahydrofolate reductase (MTHFR) and A66G of methionine synthase reductase (MTRR) genes] on Hcy levels and DNA damage in 68 patients who underwent coronary angiography. Plasma Hcy concentrations were higher in patients with multivessel disease with respect to monovessel disease and no-CAD patients (19.4+/-2.6 vs 11.6+/-1.2 and 13.7+/-1.4 micromol/l, respectively; P=0.03). 677TT patients had higher Hcy levels than those with 677CC or 677CT genotypes (26.2+/-4.3 vs 13.1+/-1.4 and 13.0+/-1.4 micromol/l, respectively; P=0.0006). No significant associations were found between A1298C and A66G polymorphisms and plasma Hcy levels. Among patients with 677CC genotype, 66GG individuals tended to have higher levels of Hcy than 66AA homozygotes (14.5+/-1.9 vs 8.9+/-0.7 micromol/l, P=0.06). Multivessel disease patients showed an increased frequency of DNA damage, measured by the micronucleus (MN) frequency, as compared to monovessel disease and no-CAD subjects (12.5+/-1.1 vs 8.5+/-0.8 and 8.2+/-0.9, respectively; P=0.006). The MN were positively correlated with Hcy levels (r=0.33, P=0.006) and were significantly higher in subjects with the 677TT genotype compared with the 677CC or 677CT genotypes (14.4+/-2.0 vs 8.8+/-1.2 and 9.5+/-0.7, respectively; P=0.006). A1298C and A66G polymorphisms had no effect on MN frequency. However, among 677TT patients, 66GG subjects tended to have higher levels of MN than those 66AG and 66AA (18.2+/-3.6 vs 13.8+/-4.0 and 10.3+/-1.7, respectively; P=NS). Our results indicate that genetic instability may be associated with increased risk for multiple Hcy-related diseases.

Methylenetetrahydrofolate reductase gene C677T polymorphism, homocysteine, vitamin B12, and DNA damage in coronary artery disease.

Elevated levels of plasma homocysteine (Hcy), a risk factor for coronary artery disease (CAD), can result from genetic errors, e.g., the methylenetetrahydrofolate reductase (MTHFR) polymorphism, or nutritional deficiencies, e.g., in vitamin B12 and folate. The mechanism by which Hcy induces atherosclerosis is not fully understood. Recently, Hcy has also been observed to induce DNA damage. In this study, we have investigated whether DNA damage is related to the C677T variant in the MTHFR gene and to plasma levels of Hcy, B12, and folate in patients with CAD. Patients ( n=46) with angiographically proven CAD were studied by using the micronucleus (MN) test, an accepted method for evaluating genetic instability. TT patients had plasma Hcy levels higher than those with the CT or CC genotypes (27.8+/-5.2 vs 13.7+/-2.2 and 12.9+/-1.9 micro mol/l, respectively; P=0.02). Patients with multi-vessel disease had higher plasma Hcy levels (11.6+/-1.2, 22.0+/-4.7, 19.3+/-3.9 micromol/l for one-, two- and three-vessel disease, respectively; P=0.05). The MN index increased with the number of affected vessels (8.4+/-0.7, 11.1+/-2.0, 14.2+/-1.7 for one-, two-, and three-vessels disease, respectively; P=0.02) and was significantly higher in subjects with the TT genotype compared with the CC or CT genotypes (15.7+/-2.4 vs 8.9+/-1.7 and 9.9+/-0.8; P=0.02). The MN index was also correlated negatively with plasma B12 concentration ( r=-0.343; P=0.019) and positively with plasma Hcy ( r=0.429, P=0.005). These data indicate that the MN index is associated with the severity of CAD and is related to the MTHFR polymorphism, suggesting an interesting link between coronary atherosclerosis and genetic instability in humans.

Urinary desmosine excretion is inversely correlated with the extent of emphysema in patients with chronic obstructive pulmonary disease.

An enhanced proteolysis of lung interstitium is key event in the pathogenesis of emphysema, a major constituent of chronic obstructive pulmonary disease. To assess whether urinary desmosine and/or hydroxyproline may be used as a marker of lung destruction we studied urinary excretions of these products in 20 patients with chronic obstructive pulmonary disease and in 19 appropriate controls in 24h urine collection samples. For desmosine measurements, we developed a new indirect competitive enzyme-linked immunosorbent assay. The extent of emphysema was measured in high resolution computed tomography (CT) scans, by considering lung area with CT numbers <-950 Hounsfield units (HU). Urinary desmosine excretion was significantly higher in patients with chronic obstructive pulmonary disease than in controls (294+/-121 microg versus 183+/-93 microg, P=0.003), and was unrelated with both age and smoking habits. In patients with no evidence or only mild emphysema, desmosine excretion values were significantly higher (P=0.006) than those of patients with moderate to severe emphysema. In patients with chronic obstructive pulmonary disease, urinary hydroxyproline excretion was positively correlated with urinary desmosine excretion but on the average, it was not different from that of controls. These data indicate that urinary desmosine is a sensitive biological marker of lung elastin catabolism. The relatively low levels of urinary desmosine observed in patients with severe emphysema may be accounted for a decrease in elastin catabolism due to reduced lung elastin mass. Urinary desmosine may be used to identify subjects at risk of developing emphysema and to assess the efficacy of therapeutic interventions.