Secondary stroke prevention strategy addressing dual mechanisms in a patient with concurrent atherothrombotic and cardioembolic risk

Introduction: Etiological classification forms the basis of treatment strategy in ischemic stroke. In older patients with vascular risk factors, cardioembolic and atherothrombotic mechanisms can coexist. In strokes with mixed mechanisms, a single-target treatment approach may not adequately reduce the risk of recurrent ischemic events. This report presents the management of a mixed-mechanism stroke in a patient with atrial fibrillation (AF), severe left ventricular dysfunction, and critical carotid atherosclerosis, and a left atrial appendage (LAA) closure approach for secondary prevention.Case: An 81-year-old woman was evaluated with a history of hypertension, coronary artery disease, heart failure (EF: 28%), and AF. She weighed 55 kg, and her creatinine was 1.47 mg/dL. Her CHA₂DS₂-VASc score was calculated as 8 and her HAS-BLED score as 3. She developed an acute ischemic stroke while taking apixaban 2.5 mg twice daily, a dose appropriate to the dose-reduction criteria. Neurological examination: oriented and cooperative, GCS 15, cranial nerve examination normal, pupils isocoric, and eye movements full in all directions. Deep tendon reflexes and pathological reflexes were normal. Muscle strength was 4+/5 in the right extremities and full in the left extremities; there was no sensory deficit or cerebellar sign. Angiography showed 80% stenosis of the left ICA and intracranial atherosclerotic narrowing of the left MCA. Cerebral circulation improved after left ICA stenting. Diffusion MRI showed multiple acute ischemic lesions in the left hemisphere in the cortical/subcortical regions, deep white matter, and watershed areas. The findings were consistent with a mixed-mechanism stroke, supporting an atherothrombotic mechanism due to critical carotid and MCA disease in addition to the cardioembolic risk associated with AF and low EF. At discharge, she was prescribed acetylsalicylic acid 100 mg and rivaroxaban 15 mg. She was referred to the cardiology outpatient clinic for contrast echocardiography/transesophageal echocardiography (TEE) at 45 days and to the neurology outpatient clinic for stent patency follow-up (Figure 1).Discussion/Conclusion: This case shows that, in strokes occurring under anticoagulation in the presence of AF, focusing only on the cardioembolic mechanism may be insufficient. The improvement in cerebral circulation after carotid revascularization demonstrated the clinical importance of the accompanying atherosclerotic component. At the same time, advanced age, low EF, a high CHA₂DS₂-VASc score, and a stroke despite anticoagulation suggest an ongoing cardioembolic risk. In strokes with mixed mechanisms, a multidisciplinary approach is needed that evaluates cardiac and vascular sources together and includes complementary strategies such as revascularization, optimization of antithrombotic therapy, and LAA closure in suitable patients.Keywords: