Oral anticoagulation: a critique of recent advances and controversies

Current status of personalized medicine based on pharmacogenetics in cardiovascular medicine

“…Another RCT also showed no significant benefit of genotype-guided dosing of acenocoumarol or phenprocoumon [15]. There were several differences in the design of the warfarin studies that were likely to have influenced the outcome, as reviewed by Pirmohamed and colleagues [16]. One of the major differences was that in the EU-PACT trial, over 98% of participants were of European origin, whereas in the COAG trial, participants included 27% African Americans and 6 to 7% Hispanics.…”

“…In the analysis from the Randomized Evaluation of LongTerm Anticoagulation Therapy (RE-LY) trial, East Asian countries mostly showed a poor level of INR control with warfarin with the TTR being low for Taiwan (44%), China (55%), Korea (55%), Japan (58%), and Hong Kong (64%) [15]. It has been suggested that non-vitamin K antagonist oral anticoagulants (NOACs) may be preferred for stroke prevention in Asians with atrial fibrillation because of reductions in major bleeding and particularly intracranial hemorrhage compared with warfarin in the large trials with NOACs [16]. Whether this should apply to all East Asians or just those who require a low dose of warfarin, who could be identified by genotyping, is another question that could be addressed by RCT.…”

Cardiovascular risk factors in elderly : With special emphasis on atrial fibrillation, hypertension and diabetes

“…In 1785 William Withering (1741-1799), an English botanist and physician, discovered the therapeutic properties of the digitalis leaf (Digitalis purpurea) and noted that a patient with weak and irregular pulse improved to have a more full and regular pulse beat [73]. Warfarin (vitamin K inhibitor) has until recently been the only available oral anticoagulant (OAC) for prevention of ischemic stroke, in clinical use for more than 60 years [74].…”

“…Warfarin is well studied, the effect can be monitored via a biomarker (INR) and is reversible with an antidote if needed [74]. There are however disadvantages with warfarin treatment; a large number of interactions with drugs and herbals, K-vitamin intake via different foods, interaction with alcohol [94], multiple blood samples and high monitoring costs [72].…”

“…Elderly patients are generally more sensitive to warfarin than younger patients. This is possibly a result of decreased liver mass with impaired capacity to eliminate warfarin as well as reduced production of clotting proteins [74].…”