[Anticoagulation of older patients: what is new?]

Abstract

Vitamin-K antagonists (VKA) are the current standard for oral anticoagulation. However, they carry several problems in older patients: frequent bleeding complications, complex management, risk of interactions with multiple drugs. Two new classes of oral anticoagulants (NOA) are now available: direct thrombin inhibitors (dabigatran); and direct factor Xa inhibitors (rivaroxaban, apixaban) and others. Their management is easier: quickly effective after administration, they are given at fixed doses and do not need regular laboratory monitoring. Several randomized trials have shown that NOA are non-inferior to heparins and VKA for treating venous thromboembolic disease (prophylactic or curative treatment) and atrial fibrillation (prevention of associated embolisms). NOA are also being studied for long-term treatment after acute coronary syndromes. Data regarding older people is still sparse. No trial has specifically studied older patients. In the context of atrial fibrillation, subgroup analysis show similar results between patients above and below 75 years old, except for dabigatran which seems to carry more bleeding complications in people older than 75 years, specially with the highest dose employed. All NOA are eliminated at least partly by kidneys. Their dose must be reduced in moderate renal failure (filtration glomerular rate (FGR) 30 to 50 ml/min) and they are contra-indicated in severe renal failure (FGR<30 ml/min). Doses of dabigatran and apixaban should be reduced in older people too. NOA also have other unresolved problems: drug interactions are still possible, specific coagulation test to assess them must be developed, and no specific antidote is currently available in case of hemorrhagic complication.