**9. Conclusions**

showed that it was at least as effective and safe as warfarin for stroke prevention in AF pa‐

All this raises questions: Is it appropriate to change oral anticoagulation with warfarin or acenocoumarol to a patient controlled? Can these NOACs impact in preventing throm‐ boembolism, especially stroke, in patients with AF? Will we monitor patients? Is it accepta‐

The Canadian Cardiovascular Society (CCS) [41], the European Society of Cardiology (ESC) [13,42,43], the American College of Cardiology Foundation (ACCF), the American Heart Asso‐ ciation (AHA) and the Heart Rhythm Society (HRS) recently updated their guidelines for the treatment of patients with AF. The guidelines report that when OAC is recommended, one of NOACs should be considered rather than adjusted-dose VKAs (INR 2.0-3.0) for most patients with AF, when studied in clinical trials to date. The NOACs provide better efficacy, safety and comfort compared to the OAC with VKAs. There is insufficient evidence to recommend one over another NOACs, although some patient characteristics, drug tolerability and compliance and the cost may be important factors in the choice of agent. As experience with NOACs is still limited, strict adherence to the recommended indications approved and aftercare marketing.

The short half-lives of NOACs compared with that do not require routine monitoring of coagu‐ lation, causes adherence is very relevant. Poor adherence increase morbidity, mortality, and in turn, overall health costs. Poor compliance can be a particular problem in patients with AF who often has no symptoms. Warfarin has a half life of 40 hours, so that a slight failure of the patient

In this context it is useful to provide a meta-analysis of clinical trials in patients treated with VKAs. The results showed that patients who achieved a treatment well stabilized, the deter‐ mination home ("self") for the same patient resulted in a significant reduction in mortality and morbidity from thromboembolism without increasing the risk of serious bleeding in a selected group of motivated adults [44]. The results of a subsequent meta-analysis showed a

The NOACs will not replace the classical therapy of oral anticoagulant therapy automatical‐ ly. As a general rule, you should not change the anti-clotting drug to patients who are cur‐ rently well controlled with acenocoumarol or warfarin and have an INR within the therapeutic range. The NOACs be reserved for those who have not attained regular values (between 2.0 and 3.0) the INR by more than 60% of the determinations despite good adher‐ ence to the prescription by the patient (for drug interactions that hinder the anticoagulation control, special dietary or digestive disorders that affect the pharmacokinetics of VKAs. Should not switch to dabigatran in patients with inadequate control of INR and nonadher‐ ence) [46], for those with mobility problems or difficulties traveling to determine the INR and for which have allergies or intolerance to the adverse effects of OACs. An anticoagulant is, by definition, a drug of high risk. And a patient with AF generally well. The fact that new drugs is involved uncertainty about their safety in the short and long term. You have to de‐ fine more precisely the role of new drugs, considered as therapeutic innovations, and they are accompanied by a careful evaluation of their efficacy and toxicity in actual practice.

will have a negligible effect on clotting compared to a drug with short half life.

reduced risk of thromboembolic disease, but no major bleeding or mortality [45].

tients, had to be withdrawn by its liver toxicity after creating many expectations [41].

ble despite the cost of not requiring monitoring? How do we assess adherence?

222 Atrial Fibrillation - Mechanisms and Treatment

Clinical trials available to date show that NOACs are at least as effective and safe as VKAs. However, although the evidence is a useful tool, it should await the development of major clinical studies in different populations to see the real benefit of these drugs. The main prob‐ lems are lacking proven methods of monitoring, so that in certain patients (elderly, low weight, renal or liver impairment...) fixed dose may not be therapeutic. There are no conclu‐ sive data on its long-term safety and are already generating security alerts in different coun‐ tries. No studies support the use of an antidote in case of overdose with bleeding. There is no justification to replace the current oral anticoagulant treatment by the NACOs in patients that conventional treatment is well tolerated and its controls are stable. Its high cost limits the use of these drugs. Independent trials are needed to precisely define the role of new drugs in patients with non-valvular AF.
