The role of platelet glycoprotein IIb / IIIa inhibitors in current treatment of acute coronary syndrome.

Current management of patients with acute coronary syndrome (ACS) includes a dual antiplatelet therapy with acetylsalicylic acid and a platelet P2Y12 receptor inhibitor. For patients without a high risk of bleeding, prasugrel and ticagrelor are preferred, since their effect is more pronounced, less dependent on metabolism of a specific patient, and occurs faster that the effect of clopidogrel. The prescription rate of platelet glycoprotein IIb/IIIa (GP IIb / IIIa) receptor inhibitors has considerably decreased. However, these drugs remain relevant in percutaneous coronary interventions in patients with a high risk of coronary thrombosis or a massive coronary thrombus, in thrombotic complications of the procedure, and in the "no-reflow" phenomenon. The intravenous route of GP IIb / IIIa inhibitor administration provides their effectiveness in patients with difficulties of drug intake or with impaired absorption of oral medications. This review presents clinical and pharmacological characteristics of various GP IIb / IIIa inhibitors and data of randomized clinical studies and registries of recent years that evaluated results of their use in patients with ACS.

Brilinta® (ticagrelor) para prevenção de síndrome coronariana aguda / Brilinta® (ticagrelor) for the prevention of acute coronary syndrome

CONTEXTO: As doenças cardiovasculares (DCV) se caracterizam por distúrbios do coração e dos vasos sanguíneos e possuem como principais causas o consumo de tabaco, inatividade física, dieta pouco saudável e uso nocivo do álcool. São consideradas a principal causa de incapacidade e morte prematura em todo o mundo, sendo uma das principais a doença arterial coronariana (DAC). A DAC se caracteriza pela presença da aterosclerose, um complexo processo inflamatório multifatorial com acúmulo de lipoproteínas no lúmen dos vasos sanguíneos de médio e grande porte e pode ser identificada clinicamente nas suas formas crônica, como a angina estável, e aguda, nas síndromes coronarianas agudas (SCA). A SCA resulta, portanto, de um desequilíbrio entre oferta e demanda de oxigênio pelo musculo cardíaco, evoluindo para isquemia miocárdica aguda. TECNOLOGIA: Brilinta® (ticagrelor). PERGUNTA: Ticagrelor é mais eficaz do que o AAS e o Clopidogrel para a prevenção de eventos trombóticos em pacientes com SCA ou com infarto prévio? EVIDÊNCIAS: A terapia combinada de inibidores da P2Y12 (clopidogrel, prasugrel ou ticagrelor) com o AAS é superior ao uso de monoterapia com AAS. Prasugrel é provavelmente mais eficaz na prevenção de eventos isquêmicos após ICP, no entanto sem diferença estatística para alta dose (AD) de clopidogrel. Ticagrelor e clopidogrel (AD) parecem encontrar um melhor equilíbrio entre eficácia e segurança. Clopidogrel (AD) é uma alternativa ao prasugrel e ticagrelor. Ticagrelor e clopidogrel (AD) apresentaram melhor eficácia do que dose padrão (DP) de clopidogrel sem diferenças estatísticas nos desfechos de segurança. CONCLUSÕES: Não houve diferenças estatisticamente significantes entre o uso de clopidogrel (AD) e ticagrelor para os desfechos de eficácia e segurança. Clopidogrel (AD) pode ser considerada como uma alternativa ao prasugrel e ticagrelor.

Randomized blinded clinical trial of intracoronary brachytherapy with 90Sr/Y beta-radiation for the prevention of restenosis after stent implantation in native coronary arteries in diabetic patients.

BACKGROUND: We report a double-blind, randomized clinical trial of intracoronary beta-radiation for prevention of restenosis after stent implantation in native coronary de novo lesions in diabetic patients. METHODS: After successful stent implantation in native coronary de novo lesions, 106 lesions in 89 diabetic patients were randomly allocated to treatment with beta-radiation with 18 Gy at 1 mm vessel depth (n = 53) or placebo treatment (n = 53). RESULTS: Angiographic analysis at 9 month follow-up revealed a late lumen loss of 0.7+/-0.9 mm in the radiotherapy group versus 1.2+/-0.8 mm in the control group at the injured segment (P = 0.006), 0.9+/-1.0 versus 1.3+/-0.7 mm at the radiated segment (P = 0.02), and 0.9+/-1.0 versus 1.3+/-0.7 mm at the target segment (P = 0.04) (defined as active source length plus 5mm on proximal and distal sites). Binary restenosis rates were significantly lower in the radiation group in all subsegments (injured segment: 10.9 versus 37.3%, P = 0.003; radiated segment: 21.7 versus 49.0%, P = 0.005; target segment: 23.9 versus 49.0%, P = 0.01). Target lesion revascularization for restenosis was required in nine lesions (17.6%) in the radiotherapy group versus 18 (34.0%) in the placebo group (P = 0.05). Late thrombosis occurred in four radiated patients (after premature discontinuation of antiplatelet therapy in all), resulting in a major adverse clinical event rate of 37.2% in the brachytherapy group versus 38.6% in the placebo group (P = ns). CONCLUSIONS: In diabetic patients with de novo coronary lesions, intracoronary radiation after stent implantation significantly reduced restenosis. However, this clinical benefit was reduced by the frequent occurrence of late thrombosis.

The role of low-molecular-weight heparin in cardiovascular diseases.

Unfractionated heparin continues to have important limitations in clinical practice. It has an inconsistent anticoagulant effect, needs frequent monitoring, and is inactivated by several plasma proteins. Low-molecular-weight heparins have a more predictable anticoagulant effect than unfractionated heparin, are easier to administer, and may not require monitoring. The anticoagulation effect of low-molecular-weight heparins is caused by a combination of inhibition of thrombin generation and inhibition of thrombin activity. Low-molecular-weight heparins have now been evaluated for a number of cardiovascular conditions and have been found to be safe and effective. We review and summarize the existing data regarding the use of low-molecular-weight heparins in cardiovascular diseases, including venous thromboembolism, percutaneous coronary interventions, and acute coronary syndromes such as ST-segment elevation myocardial infarction.