advanced cardiac imaging to predict embolic stroke on brain mri: a pilot study

Conditions: Atrial Fibrillation; Stroke; Stroke, Cardiovascular; Vascular Cognitive Impairment; Strokes Thrombotic; Stroke, Ischemic

Summary: demonstrating the pathophysiological link between left atrial (la) and left atrial appendage (laa) pathology and embolic strokes in non-atrial fibrillation (af) individuals represents a major advance in stroke prevention strategies. instead of relying on non-specific criteria for stroke risk assessment, the investigators propose to identify individuals with high-risk of embolic stroke using imaging criteria that reflect the underlying pathophysiology of embolic stroke of cardiac origin. the investigators can therefore lay the groundwork for future anticoagulation strategies for stroke prevention beyond af.

the investigators propose a cross-sectional cohort study, where individuals with no history of af and with a congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke or transient ischemic attack (tia), vascular disease, age 65 to 74 years, sex category score (cha2ds2vasc) ≥3, type ii diabetes, congestive heart failure or a history of stroke/tia will be included. data on demographics, personal health habits, medications, and medical history will be obtained by interviewing participants and reviewing the electronic medical records. all participants will undergo a cardiac magnetic resonance imaging (cmr) to assess for markers of la and laa pathology. markers of la and laa pathology that will be studied include: la fibrosis level, la functional parameters, la shape characteristics, and laa characteristics (including morphology, orifice area and flow velocity). additionally, all participants will undergo a brain magnetic resonance imaging (mri) at the same visit to assess for the presence of embolic-appearing brain infarcts, regardless of previous stroke-related symptoms. the investigators will analyze the association between each cardiac imaging feature and the prevalence of embolic-appearing strokes on brain mri to determine whether patients with higher la and laa remodeled features are more likely to have embolic-appearing brain infarcts on mri. the la and laa pathology imaging features with the strongest statistical association will be used to develop an imaging predictive score capable of identifying patients with the highest risk of embolic stroke. all brain and cardiac imaging data will be assessed by experienced operators at tulane medical center facilities. operators analyzing cmr will be blinded to brain mri results, and operators assessing brain mri will be blinded to cmr results. the study will include a single center study at tulane medical center and clinics, with investigators from different medical specialties, and the proper facilities and equipment to conduct the project accurately and safely. the investigators expect a recruitment of 120 subjects over a period of 18 months from both cardiology and neurology clinics to complete the study.

Eligibility criteria:
inclusion criteria: * male or female patients * 18 years and older * no history of atrial fibrillation * cha2ds2vasc score ≥3 * history pf type ii diabetes * history of congestive heart failure or a history of transient ischemic attack (tia)/stroke without an otherwise defined stroke etiology such as large vessel or small vessel disease exclusion criteria: * history of atrial fibrillation * patients who had a clinically symptomatic acute stroke within the last 30-days * any health-related gadolinium/mri contraindication (including previous allergic reaction to gadolinium, pacemakers, defibrillators, other devices/implants contraindicated for mri) * estimated glomerular filtration rate (egfr) cutoff in patients with chronic kidney disease (ckd) where gadolinium cannot be used equals an egfr \<30 ml/min * weighing \> 300 lbs (as cmr image quality decreases due to increased body mass index) * current pregnancy or breastfeeding * cognitive impairment preventing the patient from giving an informed consent

Keywords: magnetic resonance imaging cardiac magnetic resonance imaging brain infarcts left atrial left atrial appendage non invasive cardiac imaging