Effects of Anticoagulation on Infarct Size and Clinical Outcome in Acute Cardioembolic Stroke

Abstract

Effects of anticoagulation on infarct size and outcome have not been fully elucidated in patients with acute cardioembolic stroke, although the anticoagulation therapy reduces both occurrence and recurrence of ischemic stroke greatly. The authors retrospectively investigated the relationship of anticoagulation intensity to infarct size and outcome. In 104 consecutive patients (mean age 70.8 +/- 10.0 years) who had suffered acute supratentorial cardioembolic infarction or transient ischemic attacks, they analyzed risk factors for atherosclerosis, underlying heart diseases, the infarct size (maximal area) on brain computed tomography, and modified Rankin scale score upon discharge. They compared these clinical data between patients who had received warfarin before the ictus and those who had not. In addition, they investigated the effects of the international normalized ratio (INR) on infarct size and outcome in 19 patients who had been receiving anticoagulant therapy and had measurement of INR within 24 hours after stroke onset. There were 25 patients who had received anticoagulation before the stroke (A/C group) and 79 patients who had not (non-A/C group). The infarct size in the A/C group tended to be smaller than that in the non-A/C group (p = 0.081, Mann-Whitney U test). In the 19 patients who had prior anticoagulation and measurement of INR within 24 hours of stroke onset, large infarcts were seen in 6 of 13 patients with INR < 1.6 and in none of 6 patients with INR > or = 1.6. Poor clinical outcome was observed in 5 patients with INR < 1.6, but in none with INR > or = 1.6. In conclusion, anticoagulant therapy with INR > or = 1.6 appears to effectively prevent a large infarct and poor outcome, even when ischemic stroke dose occurs in patients with an emboligenic heart disease.

Optimal Intensity of International Normalized Ratio in Warfarin Therapy for Secondary Prevention of Stroke in Patients with Non-valvular Atrial Fibrillation.

“…2). This result was in good agreement with the INR value that had been obtained by the retrospective study comparing INR and the size of brain infarct (14). Anticoagulation with INR between 1.6 and 1.9 may have not only partial efficacy in reducing stroke occurrence (13), but it may also have an effect to prevent major ischemic events.…”

“…This study indicated partial efficacy of warfarin control with INR between 1.6 and 1.9. Wefound by a retrospective study that anticoagulant therapy with INR >1.6 effectively prevented a large infarct and poor outcome, even whenischemic stroke did occur in patients with an emboligenic heart disease (14). To determine optimal intensity of INR for secondary prevention of major ischemic and hemorrhagic events, weprospectively conducted National Cardiovascular Center (NCVC) NVAFSecondary Prevention Study and analyzed data with those of Japanese Nonvalvular Atrial Fibrillation-embolism Secondary Prevention Cooperative Study ( 1 1).…”

Prior Direct Oral Anticoagulant Therapy is Related to Small Infarct Volume and No Major Artery Occlusion in Patients With Stroke and Non‐Valvular Atrial Fibrillation

“…Although negative associations between VKA therapy and initial stroke volume9, 11, 12 or major artery occlusion10 in acute ischemic stroke patients mainly with AF were reported previously, there were few previous studies of the effect of prior DOAC treatment on infarct volume or the site of arterial occlusion. However, the relationship between DOAC therapy and small infarct volume or no proximal artery occlusion seems to be theoretically plausible, because DOAC treatment offers pharmacokinetically consistent and adequate anticoagulation 13, 14, 15, 16.…”

“…Moreover, VKA therapy, especially with sufficient anticoagulation, has been reported to reduce the severity and improve clinical outcomes when patients with AF suffer ischemic stroke, compared with those on no anticoagulation 5, 6, 7, 8. Decreasing the clot size, to avoid major artery occlusion and therefore small infarct volume is considered the main mechanism by which VKA therapy alleviates initial symptoms in acute ischemic stroke patients 9, 10, 11, 12…”

Effect of Ximelagatran and Warfarin on Stroke Subtypes in Atrial Fibrillation

“…This finding has also been reported by others. 13,14 Petty et al, 13 in their study of outcome survival and recurrence according to subtype, found that despite a higher recurrence rate and more disabling strokes in the noncardioembolic group, the group with ischemic strokes caused by arteriosclerosis had better long-term survival than those with cardiogenic stroke, even after adjustment for age, sex, AF, ischemic heart disease, congestive heart failure, and stroke severity.…”