Ec Jeffrey

Accuracy and clinical utility of the CoaguChek XS portable international normalised ratio monitor in a pilot study of warfarin home-monitoring.

Aim: To evaluate the accuracy of the CoaguChek XS international normalised ratio (INR) monitor compared with the laboratory method. Methods: The accuracy and ease of use of the recently marketed CoaguChek XS portable INR monitor was evaluated in 17 patients involved in a trial of warfarin home monitoring. INR results from the monitor were compared with those from the laboratory method. Clinical applicability was measured by discrepant INR values, defined in the literature by expanded and narrow agreement criteria, and by the proportion of INR values differing by >15% and by >20% from those derived by the laboratory method. Results: Participants provided 59 comparison INR measurements for analysis. The paired results were highly correlated (r = 0.91). Expanded and narrow agreement between paired INR values occurred 100% of the time. Only three CoaguChek XS (5.1%) results differed by >15% compared with the laboratory method; no results differed by >20% or were discrepant by >0.5 INR units. Conclusions: In the hands of patients the CoaguChek XS showed good correlation with laboratory determination of INR and compared well with expanded and narrow clinical agreement criteria. Both patients and doctors were highly satisfied with the accuracy and ease of use of the CoaguChek XS.

The risks of warfarin use in the elderly

The use of warfarin in the elderly, particularly for stroke prevention in chronic atrial fibrillation, is steadily increasing. Although the benefits of warfarin are greatest in the elderly, so are the risk of adverse outcomes and the difficulties of anticoagulant management. Clinical systems need to improve to counter this therapeutic dilemma, as warfarin is likely to remain the only widely available oral anticoagulant for the foreseeable future. Aspects that require attention are: the careful selection of patients in whom treatment with warfarin is appropriate; initiating therapy in a low dose (e.g., 2.5 – 5 mg/day); thorough education of patients and carers; close monitoring, especially with any change in the patient’s regular drug therapy; involving patients more in the management of their warfarin therapy (self-monitoring/management in suitable patients); and ongoing review of the appropriateness of therapy as circumstances change.

Antithrombotic treatment in atrial fibrillation

• Triflusal, although appearing to be a promising antiplatelet agent, is unavailable in many countries; • With mean ages 60%) of the high-risk group had mitral stenosis; • It was intriguing that amongst the composite of events within the primary outcomes of NASPEAF, the major difference between groups was in the number of sudden deaths and heart failure events, rather than ischaemic strokes; the stroke plus embolism rate did not differ significantly between groups; • The achieved intensity of anticoagulation, as reflected by mean international normailsed ratio values, was relatively similar across the groups.