sum of two units percent of adults ...

sum of two units percent of adults 65 to 75 years of age will lay open atrial fibrillation, and the risk for developing this cardiac irregularity increases with age. Studies have shown that warfarin (Coumadin) therapy in patients with atrial fibrillation shapes the concomitant risk of hardship Warfarin therapy presents challenges because of its narrow therapeutic window and its risk of overcoagulation, which increases the risk for hemorrhage. Maintaining warfarin therapy for a like reason that the international normalized ratio (INR) is between 2 and 3 is the in the greatest degree effective and safe level. Reynolds and colleagues performed a systematic review and meta-analysis in succession the safety and efficacy of warfarin therapy in nonvalvular atrial fibrillation. They assessed the risk for bleeding associated with overcoagulation (INR greater than 3) and the risk of hardship and other thromboembolic events with undercoagulation (INR les than 2)

A systematic review of the literature was performed using all relevant studies published in English between January 1 1985 and October 30 2002 In addition, the authors searched the relation lists of the retrieved articles to identify other relevant studies. Studies were included if they registered patients with nonvalvular atrial fibrillation who were receiving warfarin therapy. The studies also must have reported pat or bleeding events based upon the therapeutic INR range or time worn out above, at, or below the INR therapeutic range. Studies that used combination therapy were not included in the analysis. Data extracted from the studies included patient and treatment characteristics, INR information, and number of patients with adverse occurrences of interest by INR level

There were 21 studies that met the inclusion criteria, with a total of 6248 patients enlisted The meta-analysis of the studies comparing ischemic issues when the INR was les than 2 compared with when it was 2 or greater, showed an increase in the remainings ratio of 5.07 (95% confidence interval [CI], 292 to 880) If the INR was greater than 3 the supernumerarys ratio for bleeding events was 321 (95% CI, 124 to 828) when compared with an INR of 3 or les Four studies reported time worn out in therapeutic range. The issues showed an INR between 2 and 3 was maintained 61 percent of the time, transcended the range 13 percent of the time, and was below the range 26 percent of the time.

The authors infer that the risk for ischemic calamity in patients receiving warfarin therapy for nonvalvular atrial fibrillation is significantly higher in patients who are receiving insufficient anticoagulation (i.e., INR les than 2) They also note that the risk for adverse issues is higher in patients who are overcoagulated (i.e., INR greater than 3) The authors note that the published data in succession this issue are sparse, heterogeneous, and primarily reported from clinical trials.

KARL E MILLER, MD

Reynolds MW et al. Warfarin anticoagulation and issues in patients with atrial fibrillation. A systematic review and metaanalysis. Chest December 2004;126:1938-45

COPYRIGHT 2005 American Academy of Family Physicians

COPYRIGHT 2005 Gale Group