Phase III studies on novel oral anticoagulants for stroke prevention in atrial fibrillation: a look beyond the excellent results.

In this overview we address the three phase III studies that compared new oral anticoagulants (dabigatran, rivaroxaban and apixaban) with warfarin in the setting of stroke prevention in atrial fibrillation. Strengths and weaknesses of the studies were examined in detail through indirect comparison. We analyze and comment the inclusion and exclusion criteria, the characteristics of randomized patients, the primary efficacy and safety end points and side effects. All new oral anticoagulants resulted in being non-inferior to vitamin K antagonists in reducing stroke or systemic embolism in patients with atrial fibrillation. Dabigatran 150 mg and apixaban were superior to vitamin K antagonists. Importantly, new oral anticoagulants significantly reduced hemorrhagic stroke in all three studies. Major differences among new oral anticoagulants include the way they are eliminated and side effects. Both dabigatran and apixaban were tested in low- to moderate-risk patients (mean CHADS2 [Congestive heart failure, Hypertension, Age, Diabetes, Stroke] score = 2.1-2.2) whereas rivaroxaban was tested in high-risk patients (mean CHADS2 score = 3.48) and at variance with dabigatran and apixaban was administered once daily. Apixaban significantly reduced mortality from any cause. The choice of a new oral anticoagulant should take into account these and other differences between the new drugs.

Questions and answers on the use of dabigatran and perspectives on the use of other new oral anticoagulants in patients with atrial fibrillation. A consensus document of the Italian Federation of Thrombosis Centers (FCSA).

Dabigatran and other new oral anticoagulants (OAC) represent a step forward in stroke prevention in patients with atrial fibrillation (AF). They indeed have been shown to be an alternative to vitamin K antagonists (VKAs) without the burden of laboratory control. However, these new drugs compete with an effective and well-established therapy, thus bringing about a series of questions and doubts. In this report members of the board of the Italian Federation of Thrombosis Centers (FCSA) answer some questions every clinician might be confronted with.

Management of patients on long-term oral anticoagulant therapy undergoing elective surgery: survey of the clinical practice in the Italian anticoagulation clinics.

In the perioperative management of patients on long-term oral anticoagulant (OAC) therapy the problem is balancing the thromboembolic (TER) and the haemorrhagic risk (HR) in the perioperative period. The Federazione Centri per la diagnosi della trombosi e la Sorveglianza delle terapie Antitrombotiche (FCSA) activated an online registry from November 2001 to August 2003 in order to collect information on the management of these patients in Italy. Four hundred and eleven patients, undergoing elective major (18%) and minor surgery (82%), from 7 centres, were registered. Three hundred and ninety-nine out of 411 patients received LMWH either once a day (310 patients) or twice a day (89 patients) during OAC therapy discontinuation. Two thromboembolic (0.48%) and 16 bleeding events (7 major; 1.7%) were reported. Notwithstanding the lower doses of heparin (54.3 U/kg o.d. and 64.4 U/kg b.i.d.), the thromboembolic complications are in line with those reported in the literature. The data of this study suggest that the intervention with LMWH may be relevant only in the high-risk patients as already proposed by others.

[Oral anticoagulants and medicinal plants. An emerging interaction]. / Anticoagulanti orali e piante medicinali. Una interazione emergente.

The consumption of herbal medicines is increasing steadily throughout the world, although to our knowledge there are neither studies on their effectiveness nor controls over the quality and safety of these preparations. Considered "food integrators", these preparations are marketed without restriction. It is a common notion that natural therapy has neither side nor toxic effects: allergic reactions, direct toxic effects or those due to contamination, carcinogenicity, mutagenicity, and heavy metal toxicity have been reported as adverse events caused by herbs. Rather than replacing traditional therapy, most herbal medical treatment is used in conjunction with it. Also, the attending physician is generally not informed that the patient is using herbs. Because Passionflower, hydroalcoholic extracts, Juniper and Verbena officinalis supply variable quantities of vitamin K, they can lessen the effect of oral anticoagulant therapy. Ganoderma Japonicum, Papaw, Salvia miltiorrhiza, Ginseng, Devil's claw, Garlic, Quinine, Ginkgo, Ginger, Red Clover and Horse-Chestnut reinforce warfarin action by heterogeneous mechanisms. They should thus not be used in patients on oral anticoagulant and/or antiplatelet therapy. The scientific community must take into account the adverse events caused by interaction between herbal medicine and conventional therapy, and patients must be informed of the dangers of these preparations. If a bleeding event occurs or the quality of anticoagulant therapy is poor, the clinician should consider the possibility of interaction between conventional therapy and herbal medicine that the patient has neglected to mention he is taking.