Posters
Presenting Author Academic/Professional Position
Ridwan Lawal
Academic Level (Author 1)
Resident
Discipline/Specialty (Author 1)
Internal Medicine
Academic Level (Author 2)
Medical Student
Discipline Track
Patient Care
Abstract Type
Case Report
Abstract
Background: Atrial fibrillation is a well-established risk factor for cardioembolic stroke, with anticoagulation significantly reducing this risk. However, breakthrough ischemic strokes can still occur in anti-coagulated patients, with an estimated annual incidence of 1-2% despite appropriate direct oral anticoagulant (DOAC) therapy. These rare but consequential events challenge clinicians to maintain high diagnostic vigilance, especially in patients presenting with atypical or subtle neurological symptoms. Here, we present a case of an embolus in a patient on long-term rivaroxaban therapy, underscoring a vital clinical teaching point: therapeutic anticoagulation does not eliminate stroke risk, and homonymous hemianopsia may be the only presenting feature.
Case Presentation: A 51-year-old male with a medical history of persistent atrial fibrillation, heart failure with reduced ejection fraction (HFrEF), and type 2 diabetes mellitus presented with a one-week history of persistent headache, blurry vision, and episodic dizziness. He reported strict compliance with rivaroxaban 20 mg daily, corroborated by pill count. Neurologic examination revealed a left homonymous hemianopsia without motor or sensory deficits. Initial non-contrast head CT revealed decreased attenuation in the left parieto-occipital region, consistent with an acute non-hemorrhagic cerebrovascular accident(CVA). Due to body habits, MRI could not be performed; however, repeat CT imaging confirmed the initial findings. The clinical picture was consistent with an embolic stroke in the posterior cerebral artery territory. The patient was managed conservatively and discharged on his existing anticoagulation regimen, with plans for outpatient neurology and cardiology follow-up.
Conclusions: This case highlights an uncommon but clinically important phenomenon: ischemic stroke in the setting of therapeutic anticoagulation with rivaroxaban. While DOACs have revolutionized stroke prevention in AF, they are not infallible. Posterior circulation strokes may present subtly, often with isolated visual field deficits such as homonymous hemianopsia, which can be easily overlooked without careful neurologic examination. Clinicians must remain vigilant when evaluating patients with AF, especially those presenting with visual complaints or non-specific neurological symptoms. This case serves as a reminder that therapeutic anticoagulation significantly reduces but does not eliminate the risk of thromboembolism. Additional risk factors such as left atrial appendage morphology, renal impairment, and fluctuations in drug absorption may contribute to breakthrough events and warrant further evaluation.
Presentation Type
Poster
Recommended Citation
Lawal R, Pham A. Ischemic stroke in a patient with atrial fibrillation despite therapeutic anticoagulation with rivaroxaban. Presented at the UTRGV School of Medicine Research Colloquium; 2025 Oct, Edinburg, TX.
Included in
Cardiovascular Diseases Commons, Medical Education Commons, Nervous System Diseases Commons
Ischemic Stroke in a Patient with Atrial Fibrillation Despite Therapeutic Anticoagulation with Rivaroxaban: A Clinical Reminder
Background: Atrial fibrillation is a well-established risk factor for cardioembolic stroke, with anticoagulation significantly reducing this risk. However, breakthrough ischemic strokes can still occur in anti-coagulated patients, with an estimated annual incidence of 1-2% despite appropriate direct oral anticoagulant (DOAC) therapy. These rare but consequential events challenge clinicians to maintain high diagnostic vigilance, especially in patients presenting with atypical or subtle neurological symptoms. Here, we present a case of an embolus in a patient on long-term rivaroxaban therapy, underscoring a vital clinical teaching point: therapeutic anticoagulation does not eliminate stroke risk, and homonymous hemianopsia may be the only presenting feature.
Case Presentation: A 51-year-old male with a medical history of persistent atrial fibrillation, heart failure with reduced ejection fraction (HFrEF), and type 2 diabetes mellitus presented with a one-week history of persistent headache, blurry vision, and episodic dizziness. He reported strict compliance with rivaroxaban 20 mg daily, corroborated by pill count. Neurologic examination revealed a left homonymous hemianopsia without motor or sensory deficits. Initial non-contrast head CT revealed decreased attenuation in the left parieto-occipital region, consistent with an acute non-hemorrhagic cerebrovascular accident(CVA). Due to body habits, MRI could not be performed; however, repeat CT imaging confirmed the initial findings. The clinical picture was consistent with an embolic stroke in the posterior cerebral artery territory. The patient was managed conservatively and discharged on his existing anticoagulation regimen, with plans for outpatient neurology and cardiology follow-up.
Conclusions: This case highlights an uncommon but clinically important phenomenon: ischemic stroke in the setting of therapeutic anticoagulation with rivaroxaban. While DOACs have revolutionized stroke prevention in AF, they are not infallible. Posterior circulation strokes may present subtly, often with isolated visual field deficits such as homonymous hemianopsia, which can be easily overlooked without careful neurologic examination. Clinicians must remain vigilant when evaluating patients with AF, especially those presenting with visual complaints or non-specific neurological symptoms. This case serves as a reminder that therapeutic anticoagulation significantly reduces but does not eliminate the risk of thromboembolism. Additional risk factors such as left atrial appendage morphology, renal impairment, and fluctuations in drug absorption may contribute to breakthrough events and warrant further evaluation.
