Effect of amlodipine on exercise-induced platelet activation in patients affected by chronic stable angina.

BACKGROUND: Literature concerning exercise-induced platelet activation in chronic stable angina is somewhat confusing. The reason lies in the type of exercise as well as in methodological problems. A powerful, recently introduced procedure to detect platelet activation is flow cytometry. Platelet response to activating factors is mediated by calcium uptake; however, calcium antagonist effect on platelet activity is still unclear. HYPOTHESIS: The study was undertaken to investigate exercise-induced platelet activation before and after treatment with amlodipine in chronic stable angina. METHODS: Twenty patients with chronic stable angina were entered into the study. Each subject underwent a symptom-limited cycloergometer stress test following a washout period of 2 weeks. Blood samples were collected before and immediately after exercise. All subjects were then randomized into two groups of 10 patients each, with Group 1 and Group 2 taking amlodipine 10 mg/day, and placebo for 4 weeks, respectively. They subsequently underwent a second exercise stress test, and blood samples were obtained before and immediately after exercise. Flow-cytometric evaluation of platelet activity was performed in order to recognize GMP-140 expression on platelet membrane. RESULTS: Strenuous exercise induced a significant increase in platelet activation in all subjects prior to therapy. No significant differences were observed in platelet activity at rest between Groups 1 and 2, whereas a significant decrease in exercise-induced platelet activation was demonstrated in Group 1 compared with Group 2. CONCLUSION: Our data provide evidence of the favorable effect of amlodipine on exercise-induced platelet activation in patients affected by chronic stable angina.

Cholesterol and fibrinogen as predictive factors of progressive carotid atherosclerosis.

In order to detect the presence of determining factors as predictors of progressive carotid atherosclerosis, the incidence of total serum cholesterol and fibrinogen elevation was evaluated in patients affected by coronary artery disease (CAD). 61 subjects with CAD (mean age 62 years) and significative lesions (> 50%) underwent periodic Echo-Doppler (Duplex scanning) of the supra aortic branches. Total serum cholesterol, HDL, LDL and fibrinogen were monitored, as well. A 24 month follow-up period was performed. Indicative of the progression of carotid atherosclerosis has been considered the presence of a stenosis degree over 20% than the initial one. In 14 of the 61 subjects who entered the study, there was evidence of progressive carotid atherosclerosis. The same patients showed higher levels of LDL cholesterol (130 +/- 36.3 vs 96.5 +/- 33.2) and Fibrinogen (398.3 +/- 59.4 vs 328 +/- 36.8) and lower levels of HDL cholesterol (27.2 +/- 4.2 vs 34.4 +/- 10.1). Our results confirm the importance of cholesterol and fibrinogen as determining risk factors, especially in patients with multiple vascular disease (coronary and carotid).

Incidence of carotid artery atherosclerosis in patients with coronary artery disease.

The natural history of coronary artery disease (CAD) is often complicated by cerebrovascular accidents. The real incidence of atherosclerotic lesions of carotid arteries in coronary patients is not well established. In order to detect a high-risk group for stroke development, 184 patients affected by CAD, either partially symptomatic or asymptomatic for carotid artery stenosis, underwent Echo-Doppler ultrasonography (duplex scanning) of supra-aortic branches. Significant carotid stenosis (> 50%) was demonstrated in 51 subjects (27.7%); 21 subjects (41.2%) were partially symptomatic (dizziness, vertigo, lipothymia, etc), and 30 subjects (58.8%) were completely asymptomatic. The authors' data suggest that carotid disease can develop concurrently with coronary disease in a significant proportion of patients, even though completely asymptomatic. In order to obtain optimal long-term results, both coronary and carotid artery disease require appropriate evaluation and either medical or surgical management. For these reasons they recommend duplex scanning as a routine screening procedure in patients affected by CAD.

Effects of coffee on serum cholesterol and lipoproteins: the Italian brewing method. Italian Group for the Study of Atherosclerosis and Dismetabolic Diseases, Rome II Center.

In order to evaluate the effects of Italian brewed coffee (moka) on cholesterol and serum lipoproteins, a randomized double-blind 14-week clinical trial was performed. After a coffee-free period of four weeks, 49 subjects drank coffee, caffeinated and decaffeinated, for ten weeks. There was no evidence that the Italian method of brewing coffee affects serum lipoproteins since no statistically significant differences were found.

[Effects of physical activity on lipids and coagulation]. / Effetto dell'attività fisica sull'assetto lipidico e sulla coagulazione.

In order to evaluate the effects of physical activity on seric lipoproteins and coagulation parameters, an 8-week clinical trial was performed. Fifteen healthy young subjects (average age 23 years) with no history of previous agonistic physical activity, entered the study. Each subject underwent a physical programme consisting of three times a week bicycle ergometer exercise with progressive increases in work rate by using stages of 3 min duration until the 85% of the predictive heart rate was reached. Each individual was subjected to four blood drawings according to the following schedule: at the beginning of the study, after 4 weeks, after 8 weeks (at the end of the programme) and 4 weeks after the interruption of training. As far as the seric lipoproteins are concerned, the following parameters were monitored: total cholesterol, HDL-C, LDL-C, VLDL-C, triglycerides, Apo-A1, Apo-B100, NEFA and phospholipids. On the other hand the following coagulation parameters were monitored: fibrinogen PT, aPtt, coagulation factors (II-XII), red cells, leucocytes, platelets, hemoglobin and hematocrit. From the analysis of the data, the following statistically significant results were observed: HDL-C increased by 14%, LDL-C decreased by 13%, Apo-A1 increased by 6%, fibrinogen increased by 31.7%, Ptt decreased by 3.7% and leucocytes increased by 15%. Four weeks after exercise was terminated, all monitored parameters turned into the basal range. Our data seem to demonstrate a positive effect of physical exercise on seric lipoproteins in the short period. Nevertheless they provide evidence of an hypercoagulability condition demonstrated by the important fibrinogen increase and the Ptt decrease.