RESUMO
Patients on rivaroxaban requiring percutaneous coronary intervention (PCI) represent a clinical conundrum. We aimed to investigate whether rivaroxaban, with or without an additional bolus of unfractionated heparin (UFH), effectively inhibits coagulation activation during PCI. Stable patients (n=108) undergoing elective PCI and on stable dual antiplatelet therapy were randomised (2:2:2:1) to a short treatment course of rivaroxaban 10 mg (n=30), rivaroxaban 20 mg (n=32), rivaroxaban 10 mg plus UFH (n=30) or standard peri-procedural UFH (n=16). Blood samples for markers of thrombin generation and coagulation activation were drawn prior to and at 0, 0.5, 2, 6-8 and 48 hours (h) after start of PCI. In patients treated with rivaroxaban (10 or 20 mg) and patients treated with rivaroxaban plus heparin, the levels of prothrombin fragment 1 + 2 at 2 h post-PCI were 0.16 [0.1] nmol/l (median) [interquartile range, IQR] and 0.17 [0.2] nmol/l, respectively. Thrombin-antithrombin complex values at 2 h post-PCI were 3.90 [6.8]µg/l and 3.90 [10.1] µg/l, respectively, remaining below the upper reference limit (URL) after PCI and stenting. This was comparable to the control group of UFH treatment alone. However, median values for thrombin-antithrombin complex passed above the URL with increasing tendency, starting at 2 h post-PCI in the UFH-alone arm but not in rivaroxaban-treated patients. In this exploratory trial, rivaroxaban effectively suppressed coagulation activation after elective PCI and stenting.
Assuntos
Doença das Coronárias/cirurgia , Inibidores do Fator Xa/uso terapêutico , Intervenção Coronária Percutânea , Complicações Pós-Operatórias/prevenção & controle , Rivaroxabana/uso terapêutico , Trombose/prevenção & controle , Idoso , Anticoagulantes/uso terapêutico , Antitrombina III/análise , Biomarcadores/sangue , Quimioterapia Combinada , Procedimentos Cirúrgicos Eletivos , Inibidores do Fator Xa/administração & dosagem , Feminino , Fibrinolíticos/uso terapêutico , Heparina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/análise , Peptídeo Hidrolases/análise , Inibidores da Agregação Plaquetária/uso terapêutico , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/sangue , Protrombina/análise , Fatores de Risco , Rivaroxabana/administração & dosagem , Método Simples-Cego , Stents , Trombina/biossíntese , Trombose/sangueRESUMO
BACKGROUND: Folic acid is assumed to have favourable effects on vascular endothelium, directly as well as indirectly through its effect on homocysteine metabolism. However, the clinical value of folic acid in secondary prevention after acute myocardial infarction (MI) has never been tested. Thus, a randomised, open-label, multicentre trial was performed in order to study the effect of folic acid 5 mg o.d. when added to statin therapy on the incidence of recurrent major clinical events up to 1 year post-MI. METHODS: A total of 283 patients with a total cholesterol >6.5 mmol/l (251 mg/dl) (mean 7.3 mmol/l) were included. All patients received 40 fluvastatin. In 140 of the 283 patients, folic acid (5 mg o.d.) was instituted at discharge, and the remaining 143 patients served as controls. Other secondary prevention measures for both groups were advocated. The primary endpoint was a composite consisting of all vascular events, including death, recurrent MI, strokes, and unplanned invasive coronary interventions. RESULTS: At baseline, the two groups were well-matched for all clinical and demographic parameters. After 1 year of treatment, no difference was noticed in the primary endpoint between the two groups. These endpoints occurred in 43 patients (31%) in the folic acid group, as opposed to 45 patients (31%) in the control group. All separate cardiovascular events were also equally distributed between both groups. Total cholesterol levels decreased to a similar extent in the two groups (to 5.5 and 5.7 mmol/l, in folic acid and control groups, respectively). CONCLUSIONS: In this medium-size pilot study, folic acid did not demonstrate any beneficial additive effects on cardiovascular mortality or morbidity in post-MI patients with hypercholesterolemia who were treated with statin therapy. Larger trials, possibly targeting at selected populations, must be awaited before definitive conclusions regarding the potentially favourable effects of folic acid supplementation in secondary prevention can be drawn.