RESUMO
INTRODUCTION: Current guidelines still recommend the bolus and infusion administration of glycoprotein IIbIIIa inhibitors in patients with high-risk acute coronary syndrome undergoing percutaneous coronary intervention. We sought to evaluate the extent of platelet inhibition by a blocking and bridging strategy with intracoronary abciximab bolus-only administration and oral loading of adenosine diphosphate receptor antagonists. PATIENTS AND METHODS: Fifty-six consecutive high-risk acute coronary syndrome patients with bolus-only abciximab administration (0.25 mg/kg i.c.) and loading with 600 mg clopidogrel (55%) or 60 mg prasugrel (45%) were included in this study. Platelet aggregation induced by thrombin receptor-activating peptide and adenosine diphosphate was measured by multiple electrode aggregometry up to 7 days. RESULTS: Thrombin receptor-activating peptide induced platelet aggregation was significantly suppressed for a minimum of 48 h (45±17U) and returned to a normal range (>84 U) after 6 days (90±26U; p<0.001). Co-medication with prasugrel significantly reduced adenosine diphosphate-induced (p=0.002) and thrombin receptor-activating peptide-induced (p=0.02) platelet aggregation compared with clopidogrel throughout the observation period. No stent thrombosis or repeat myocardial infarction occurred at 30-day follow-up. CONCLUSIONS: Immediate blocking of platelet aggregation in high-risk acute coronary syndrome patients by intracoronary abciximab bolus-only administration and bridging to prolonged inhibition via oral blockade of ADP receptors effectively inhibited overall platelet reactivity for at least 48 h, questioning the value of continuous abciximab infusion. Co-medication with prasugrel vs. clopidogrel synergistically augmented platelet inhibition.
Assuntos
Síndrome Coronariana Aguda/tratamento farmacológico , Anticorpos Monoclonais/administração & dosagem , Fragmentos Fab das Imunoglobulinas/administração & dosagem , Piperazinas/administração & dosagem , Inibidores da Agregação Plaquetária/administração & dosagem , Antagonistas do Receptor Purinérgico P2Y/administração & dosagem , Tiofenos/administração & dosagem , Ticlopidina/análogos & derivados , Abciximab , Administração Oral , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Plaquetas , Clopidogrel , Vias de Administração de Medicamentos , Feminino , Humanos , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Piperazinas/uso terapêutico , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/uso terapêutico , Testes de Função Plaquetária , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Cloridrato de Prasugrel , Antagonistas do Receptor Purinérgico P2Y/uso terapêutico , Tiofenos/uso terapêutico , Ticlopidina/administração & dosagem , Ticlopidina/uso terapêuticoRESUMO
A mass spectrometer was coupled to high-performance ligand-exchange liquid chromatography (HPLEC) for simultaneous analysis of stress associated solutes such as proline, hydroxyproline, methylproline, glycine betaine and trigonelline extracted from leaves of drought stressed oaks and an internal standard namely N-acetylproline. Methanol/chloroform/water extracts were analyzed using an Aminex HPX-87C column and specifically quantified by the positive ion mode of an electrospray ionisation-mass spectrometry (ESI-MS) in single ion monitoring (SIM) mode. The recovery of N-acetyl proline added to oak leaf extracts ranged from 85.2 to 122.1% for an intra-day study. Standard calibration curves showed good linearity in the measured range from 0.3125 to 10micromolL(-1) with the lowest correlation coefficient of 0.99961 for trigonelline. The advantages of this alternative procedure, compared to previously published methods using fluorescence or amperometric detections, are the simultaneous and direct detection of osmoprotectants in a single chromatographic run, a minimal sample preparation, a good specificity and reduced limits of quantification, ranging from 0.1 to 0.6micromolL(-1). Fifty-six days of water deficit exposure resulted in increased foliar free proline levels (2.4-fold, P<0.001, 155micromolg(-1) FW) and glycine betaine contents (2.5-fold, P<0.05, 175micromolg(-1) FW) of drought stressed oak compared to control.