TITLE:
Recurrent Ischemic Stroke Despite Therapeutic Anticoagulation: Evidence of Dual Embolic Mechanisms—Running Head: Breakthrough Stroke with Dual Embolic Origin
AUTHORS:
Lehleng Agba, Kokou Mensah Guinhouya, Komla Nyinèvi Anayo, Adama Ephoevi-Ga, Kossivi Apetse, Vinyo Kodzo Kumako, Damelan Kombaté, Komi Assogba, Belo Mofou, Agnon Ayélola Balogou
KEYWORDS:
Ischemic Stroke, Atrial Fibrillation, Breakthrough Stroke, Carotid Atherosclerosis, Dual Embolic Mechanism, Anticoagulation, Sub-Saharan Africa
JOURNAL NAME:
World Journal of Neuroscience,
Vol.16 No.3,
August
14,
2026
ABSTRACT: Background: Ischemic stroke occurring despite effective oral anticoagulation, termed “breakthrough stroke,” represents a diagnostic and therapeutic challenge. It may indicate the presence of alternative or concomitant etiological mechanisms beyond the initially identified cause. Data regarding such situations remain limited in sub-Saharan Africa. We report a case of recurrent ischemic stroke despite therapeutic anticoagulation, revealing a dual embolic origin. Methods and Findings: A 50-year-old right-handed woman with poorly controlled hypertension was admitted for sudden onset left-sided hemiparesis (NIHSS score 13). Non-contrast brain CT scan showed a hypodensity in the territory of the right middle cerebral artery. Electrocardiogram revealed atrial fibrillation. Anticoagulation was initiated with enoxaparin followed by fluindione, achieving a therapeutic INR of 2.3. Initial evolution was favorable, with motor improvement at day 14 (NIHSS score 6). Three weeks later, the patient was readmitted for worsening neurological deficit despite good treatment adherence (INR 2.05). Follow-up CT scan showed extension of the infarction in the same vascular territory. Further etiological evaluation with Doppler ultrasound revealed significant right internal carotid artery stenosis with an unstable, ulcerated plaque. The coexistence of atrial fibrillation and carotid atherosclerosis suggested a dual embolic mechanism. The clinical course was unfavorable, with progressive neurological deterioration leading to death. Conclusions: This case illustrates the complexity of etiological reasoning in ischemic stroke. Stroke occurring despite adequate anticoagulation should prompt systematic reassessment for alternative or additional embolic mechanisms. In resource-limited settings, comprehensive etiological evaluation remains a major challenge requiring a pragmatic and individualized approach.