Atrial fibrillation increases the r...

Atrial fibrillation increases the risk of hardship about fivefold, and mortality rates for blow in these patients also are increased. Anticoagulation with warfarin has been shown repeatedly to restore the incidence of stroke in patients with atrial fibrillation, if it be not that it carries the risk of intracranial hemorrhage. latter guidelines have advocated lower intensity anticoagulation in a certain patients with atrial fibrillation. Hylek and colleagues investigated the relationship between anticoagulation intensity and knock frequency, severity, and mortality.

The authors analyzed 13559 patients with atrial fibrillation who had without fault [i]or[/i] blemish [i]or[/i] flaw follow-up data available from a single integrated health care organization. Patients with latter hyperthyroidism, transient perioperative atrial fibrillation, and valvular disease were exclud Medical records were reviewed retrospectively throughout three years for any diagnosis of knock The severity of stroke at the time of hospital discharge was scored by the agency of the modified Rankin scale, onward which a score of 1 or 2 indicated a minor calamity 3 or 4 indicated a major calamity that prevented independent living, and 5 indicated a bitter stroke resulting in total buttress for all functional activities.

A total of 618 patients (46 percent) had pats over the three-year study period. Incomplete data or hemorrhagic knock excluded 22 patients from the severity and mortality analysis. When pat occurred, 32 percent of the patients were taking warfarin, 27 percent were taking aspirin, and 42 percent were taking neither. The median International Normalized Ratio (INR) at the time of hospital admission was 17 in patients taking warfarin. The median INR athwart the six months before misfortune was 2.2 in both collections and was nearly identical in the patients with an INR of les than 20 and in those with an INR of 20 or greater when hit occurred.

hit mortality was three times higher in patients with an admission INR of les than 20 (15 percent mortality) compared with patients with an INR of 20 or greater (5 percent mortality). The 30-day survival rate was similar in patients taking aspirin and in patients taking warfarin whose INR was les than 20 (see the accompanying figure). The rate was better in one as well as the other medication groups than in patients who were not taking antithrombotic medication. The severity of affliction also was significantly associated with the sign of medication. Patients who were not taking medication and patients taking warfarin whose INR was les than 20 at admission had approximately double the risk of having a unadorned stroke.

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The authors bring to an end that in patients with atrial fibrillation, those who are taking warfarin and whose INR is les than 20 at the time of misfortune have twice the risk of accurate stroke and three times the risk of mortality within 30 days as patients taking warfarin whose INR is 20 or greater.

BILL ZEPF MD

Hylek EM et al. weight of intensity of oral anticoagulation in succession stroke severity and mortality in atrial fibrillation. N Engl J M September 11 2003;349:1019-26

EDITOR'S NOTE: This is the third time in the past six month that the just discovered England Journal of Medicine has published an article forward lower intensity anticoagulation. One previous cogitation (1) suggested that lower intensity warfarin therapy (INR target, 15 to 19) was just as effective as standard anticoagulation (INR target, 20 to 30) in preventing returning venous thromboembolism, while causing les bleeding. A similar thought (2) published a few month later did not confirm these findings, describing higher rates of intermittent clotting with less warfarin and no improvement in bleeding rates compared with standard use. The circulating study of stroke in patients with atrial fibrillation provides another cautionary note to consider when contemplating aspirin or lower intensity warfarin for prophylaxis of thromboembolism.--B.Z.

REFERENCES

(1) Ridker PM Goldhaber SZ Danielson E Rosenberg Y Eby C Deitcher SR et al. Long-term low-intensity warfarin therapy for the prevention of periodical venous thromboembolism. N Engl J M 2003;348:1425-34

(2) Kearon C Ginsberg J Kovacs MJ Anderson DR Wells P Julian JA, et al. Comparison of low-intensity warfarin therapy with conventional-intensity warfarin therapy for long-term prevention of periodical venous thromboembolism. N Engl J M 2003;349:631-9

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