Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.1.6 (CAD)
 4,420 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many recent studies provide evidence that increased platelet activation occurs in a significant number of patients with atherosclerotic coronary artery disease. The mechanisms responsible for this activation are unknown, although there have been studies suggesting a correlation with abnormal lipoproteinemia, acute myocardial infarction, unstable angina, and exercise-induced myocardial ischemia. We studied 84 patients undergoing standardized treadmill exercise using either a Bruce [N = 63] or symptom-limited Naughton protocol [N = 21]. In contrast to ten healthy volunteer subjects, the patient group demonstrated a significant increase in plasma concentrations of platelet factor 4 [PF4] between pre- and postexercise blood samples confirming earlier reports of exercise-induced platelet activation and secretion. As with previous studies, however, only a subset of patients demonstrated this response. When the entire group was analyzed for the presence or absence of electrocardiographic ischemic changes and the presence of documented versus suspected coronary artery occlusions, there were no differences noted between groups that explained the variable responses measured. However, there was a significant difference between patient groups when analyzed by whether or not they were being treated with beta-blocking agents. Patients who were being treated with propranolol or one of the longer-acting beta-blocking agents did not have a significant increase in plasma PF4 following exercise, in contrast to patients who were not beta-blocked. Plasma concentrations of epinephrine, norepinephrine, and lactic acid were measured in 49 patients and all normal subjects. There was no correlation between the changes in plasma PF4 concentrations and any of these three variables, suggesting that platelet activation was not occurring through direct platelet activation by circulating catecholamines. This study provides further evidence that there is a subset of CAD patients with platelet hyperactivity. This is the first time that beta-blockade has been demonstrated to modify this platelet response. The effectiveness of beta-blocking agents in CAD may be in part related to their antiplatelet effect.
 ...
PMID:Platelet factor 4 release during exercise in patients with coronary artery disease. 614 87

It is generally accepted that atherosclerosis is a dynamic process in which many factors of lipid, hemostatic or other nature play their negative and positive roles. The purpose of the study was to determine the relationship between the atheromatous changes in coronary arteries being assessed angiographically and the lipid and hemostatic risk factors, as well as to select biochemical parameters, which would be helpful for prognosing the degree of intensity with regard to atheromatous changes in coronary arteries. Studies of lipid parameters and hemostasis system were performed in 31 men with atherosclerosis of coronary vessels being angiographically estimated. The degree of intensity concerning the atheromatous changes was defined in a point scale according to Gensini based on the magnitude of coronary artery stenosis and its localization in respect of significance for myocardial function. The studied patients were divided into two groups, which differed by the degree of the intensity of atheromatous changes in coronary arteries: group I--men with mild (M-CAD, score < 32) n = 15, group II--men with severe atherosclerotic changes (S-CAD, score > or = 32) n = 16. The characteristics of both groups are given in table 1. All patients were on nitrates, salicylates, beta-blockers and calcium channel blockers. No antilipemics or anticoagulants were administered. The following biochemical parameters were determined in all men: cholesterol-Ch; triglycerides-TG; phospholipids-PL; apolipoproteins: Apo A, Apo A-I, Apo B; lipoproteins: VLDL, LDL, HDL and their lipids and proteins components; lipoprotein (a)-Lp(a); fibrinogen-Fb; euglobulin lysis time-ELT; inhibitor tissue plasminogen activator PAI-1; antithrombin III--AT III; spontaneous platelet aggregation-SPA, platelet factor 4-PF 4 and glucose. Table 2 lists the lipid parameters in serum and lipoprotein fractions. The levels for apolipoproteins A, A-I, B, lipoprotein (a), hemostatic parameters and glucose are given in table 3. Tables 4 and 5 present the results of multiple regression analysis for severity of atherosclerotic changes (score--dependent variable y) lipid and hemostatic parameters and glucose (independent variables x) in both groups. Prognostic variables necessary for the best fit in the model of relationship studied have been selected. Independent variables x are listed in descending order according to the absolute value of b*x. On the basis of the performed statistical analysis of the results of studies it has been ascertained that the biochemical parameters differentiating the patients with regard to the intensity of atheromatous changes are the coefficients: LDL-Ch/HDL-Ch and Apo B/Apo A ratio, LDL-PL, Fb and ELT whose values were higher as well as HDL-Apo A-I whose value was lower in the group of men with more severe atherosclerotic changes in coronary arteries (S-CAD). The stepwise multivariate analysis indicates that the most profound prognostic significance in risk of coronary atherosclerosis is claimed successively by: glucose, LDL-PL, HDL-Apo A-I, AT III, Fb, ELT, PAI-1, SPA, Lp(a), Apo B and PF 4. The results of the accomplished studies point out that the above-mentioned lipid, hemostatic parameters and glucose may be helpful in prognosing the severity of coronary atherosclerosis.
 ...
PMID:[Determination of the usefulness of selected biochemical parameters for assessing the advanced atheromatous changes in human coronary arteries]. 985 30