Granulocyte function in coronary artery disease.

Granulocytes defend the body against invading microbes by producing a complex armamentarium of toxic substances, such as proteolytic enzymes, oxygen radicals and arachidonic acid metabolites. Under certain circumstances, however, such compounds may be released in the absence of phagocytosable particles, resulting in injury to normal cell and connective tissue degradation. Recent experimental studies have emphasized the potential role of granulocytes in the pathogenesis of myocardial ischemia. Clinical investigations have also shown alterations in neutrophil function in stable and unstable clinical manifestations of ischemic heart disease. "Priming" of granulocytes in stable forms of coronary disease may predispose to the subsequent development of acute coronary events, whereas activation of neutrophils may lead to alterations in vascular permeability and coronary flow regulation, leading to further myocardial and endothelial injury in acute myocardial infarction, unstable angina and coronary angioplasty.

[Protection against ischemic damage during percutaneous coronary angioplasty]. / La protezione del danno da ischemia durante angioplastica coronarica percutanea.

Minimizing ischemia during percutaneous transluminal coronary angioplasty (PTCA) may lower the risks of the procedure and enhance the short- and long-term success rates of the procedure. However we have to remember that the effects of pharmacological and mechanical interventions during PTCA may be influenced by the functional status of the myocardium. In man the myocardium supplied by a stenotic coronary artery may have a normal metabolic condition or may be stunned, hibernated or even preconditioned by previous ischemic episodes, while the procedure itself may provoke stunning or preconditioning. Many different drugs have been tested for their efficacy under this clinical setting but we recognize that the prolongation of balloon inflation time, though statistically significant, has never proved to be so large to be clinically relevant. Mechanical antegrade coronary infusion (with either blood or oxygenated fluorocarbons) offers the most reliable method for prolonged periods of myocardial protection during PTCA.

Similar antiischemic effects of intracoronary atenolol and nifedipine during brief coronary occlusions in humans.

To compare the antiischemic effects of intracoronary administration of a beta blocker, atenolol, and of a calcium antagonist, nifedipine, on the clinical and electrocardiographic signs of myocardial ischemia induced by balloon occlusion of the coronary artery, we studied 32 consecutive patients undergoing routine PTCA. In each patient at least three balloon inflations were performed: the first served to verify the occurrence of ischemia (ST segment depression/elevation greater than 1.5 mm); the second was used as a control occlusion; the third was performed after the patients were assigned to receive either atenolol 1.0 mg IC (group 1, N = 16) or nifedipine V = 0.2 mg IC (group 2, N = 16). In a control population of 10 patients, the time to return to baseline of the ECG tended to be progressively shorter during the three consecutive inflations, but the other clinical and ECG parameters did not change significantly. In group 1 and group 2, two patients did not show ECG signs of ischemia at the third inflation; the time to ischemia increased in group 1 (+76%, p less than .001) and group 2 (+85%, p less than .01; NS group 1 versus group 2); ST segment displacement at 30 seconds decreased in group 1 (-38%, p less than .01) and group 2 (-36%, p less than .01; NS group 1 versus group 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of two buflomedil tablet formulations in patients with atherosclerotic disease.

The bioequivalence of a 600-mg methocel tablet containing buflomedil hydrochloride in sustained-release form was determined relative to a 300-mg CAP/carbovax-coated tablet of buflomedil hydrochloride in immediate-release form. The tablets were given to 20 patients in a double-blind placebo-controlled clinical study with cross-over between the administration plans. The 300-mg tablets were given b.i.d., at 8 a.m. and 8 p.m. while the 600-mg tablets were taken once a day at 8 a.m. (+placebo at 8 p.m.). Plasma samples were collected at appropriate times up to 24 h after administration and were analyzed for buflomedil with a validated high-performance liquid chromatographic procedure. Results showed an overall significant mean difference in absorption rate between the two formulations. The mean tmax (5.5 +/- 3.5 h) for the 600-mg tablet was longer (P < 0.001) than the tmax value (1.8 +/- 0.8 h) seen after administration of the first 300-mg tablet. Analysis of AUC(O-infinity) values indicated that the sustained-release preparation (32.1 +/- 20.7 micrograms/ml h) was not significantly different from the 300-mg tablet b.i.d. (28.7 +/- 16.0 micrograms/ml h). Furthermore, it was seen that single administration of a 600-mg sustained-release tablet of buflomedil hydrochloride delivered the same amount of total drug as a 300-mg tablet given twice a day.

The trapidil restenosis trial (STARC study): background, methods and clinical characteristics of the patient population.

Restenosis remains the principal drawback of percutaneous transluminal coronary angioplasty (PTCA) since 30-35% of patients still experience it 6 months after the intervention. Several studies have clearly demonstrated that restenosis is a complex multifactorial process that involves smooth muscle cell (SMC) migration and proliferation in the intimal layer of the coronary artery. Among others, the platelet-derived growth factor (PDGF) seems to play an important role in this process. That is why researches have been made in finding and developing new agents able to inhibit PDGF. Trapidil (triazolopyrimidine) (T), is a potent PDGF inhibitor that has been efficacious in preventing restenosis after balloon angioplasty in the experimental animal and after PTCA in a limited clinical trial. The Trapidil Restenosis Trial (STARC study) is a double blind randomized trial of T 100 mg t.i.d. vs. Aspirin (ASA) 100 mg t.i.d. 360 patients have been enrolled from April 1990 until May 1992, excluding recent myocardial infarctions, thrombolysis, restenotic and venous graft lesions and 302 have terminated follow-up. This paper describes the clinical background, the protocol and baseline data of the patient population including data regarding initial stenosis and type of vessel treated.