Relationships of glycoproteins IIb-IIIa and Ib content with mean platelet volume and their genetic polymorphisms.

Quantity of platelet adhesion molecules significantly varies in normal donors and cardiovascular patients and might be affected by platelet size and genetic variations. In this study, we assessed relationships of the content of glycoprotein (GP) IIb-IIIa and GPIb with mean platelet volume (MPV) and their genetic polymorphisms. MPV and GPIIb-IIIa and GPIb numbers were measured in 116 patients with acute coronary syndrome (ACS) at days 1, 3-5 and 8-12 after disease onset and in 32 healthy volunteers. GPIIb-IIIa and GPIb allelic variants were determined in ACS patients. Strong interactions of GPIIb-IIIa and GPIb numbers and MPV were observed in ACS patients and healthy volunteers. In patients, coefficients of correlation (r) were 0.642 and 0.510 (analysis of individual mean values) and in volunteers - 0.594 and 0.508 for GPIIb-IIIa and GPIb, respectively (everywhere P < 0.005). In ACS patients, correlations were highly significant at each tested time point. GPIIb-IIIa and GPIb genetic polymorphisms [GPIIIa Leu33Pro, GPIbα Thr145Met and GPIbα (-5)T/C (Kozak)] determined in ACS patients had no significant impact on their expression. Modest correlation was revealed between MPV and plasma thrombopoietin (TPO) measured at the first day of ACS (r = 0.279, P = 0.005). The data obtained indicated that GPIIb-IIIa and GPIb levels are mainly affected by platelet size (MPV) but not by their genetic variations. In some ACS patients, production of large platelets with high GPIIb-IIIa and GPIb contents might be stimulated by elevated TPO.

Eptifibatide does not suppress the increase of inflammatory markers in patients with non-ST-segment elevation acute coronary syndrome.

BACKGROUND: Platelets are involved in inflammatory reactions which play an important role in the development of atherosclerosis and its acute complications. The objective of this study was to test the ability of glycoprotein (GP) IIb-IIIa antagonist eptifibatide to suppress the increase of inflammatory markers in non-ST-segment elevation acute coronary syndrome (ACS). METHODS: Twenty-five patients with unstable angina and non-ST-segment elevation myocardial infarction received eptifibatide on admission (two 180 microg/kg boluses followed by infusion at 2.0 and 1.3 microg/kg/min for 24 and 48 h, respectively) and 25 were treated without GP IIb-IIIa antagonists. Plasma von Willebrand factor (vWF) and soluble P-selectin were determined at baseline, 48 h and 2 weeks after onset of ACS, and were also measured in a group of healthy volunteers. Serum C-reactive protein (CRP), tumor necrosis factor alpha (TNFalpha), and interleukin 6 (IL6) were measured at baseline, 48 h, 2 weeks and 6 months. RESULTS: P-selectin was increased at baseline and vWF at baseline, 48 h and 2 weeks in comparison with healthy donors. CRP, TNFalpha, but not IL6 were increased at baseline, 48 h and 2 weeks in comparison with their levels at 6 months. Maximal values of CRP, TNFalpha and vWF were detected at 48 h. At any time point eptifibatide failed to decrease the levels of all tested markers. CONCLUSION: Eptifibatide does not suppress elevated levels of inflammatory markers in patients with non-ST-segment elevation ACS.

Efficacy of azimilide for the maintenance of sinus rhythm in patients with paroxysmal atrial fibrillation in the presence and absence of structural heart disease.

Azimilide hydrochloride (azimilide), an investigational antiarrhythmic drug, has shown variable efficacy in preventing atrial fibrillation (AF). This study was designed to assess its efficacy in maintaining sinus rhythm in patients with paroxysmal AF and heart disease. Patients with symptomatic paroxysmal AF were screened for 1 month by transtelephonic monitoring. After recording 1 episode of AF in the screening period, they were randomized to receive azimilide 125 mg or placebo once daily. Patients were stratified by the presence or absence of congestive heart failure or coronary heart disease (CHF/CHD). A maximum of 220 patients without CHF/CHD were randomized, with the remainder having CHF/CHD. Patients with CHF/CHD were monitored for 3 days during loading. The primary efficacy analysis was the time to the first symptomatic recurrence of AF in the CHF/CHD group. Secondary analyses were the time to the first recurrence in the entire population and the time to the first recurrence in those with significant structural heart disease. The median time to recurrence of AF in the CHF/CHD group was 10 days in the 2 treatment arms. Nonsignificant trends were seen toward efficacy of azimilide in the CHF/CHD group (hazard ratio 1.28, 95% confidence interval 0.97 to 1.70, p=0.087), structural heart disease group (hazard ratio 1.22, 95% confidence interval 0.96 to 1.56, p=0.11), and overall group (hazard ratio 1.22, 95% confidence interval 1.00 to 1.49, p=0.053). No patient died. In conclusion, azimilide showed a nonsignificant trend toward efficacy in maintaining sinus rhythm in patients with AF.