Echocardiographic Risk Factors of Stroke in Patients With Atrial

Atrial fibrillation is the most common heart rhythm disorder seen in clinical practice. Patients with atrial fibrillation are at increased risk for stroke. This risk is determined by several factors. Congestive heart failure, hypertension, age, diabetes, female sex, previous history of heart attack or vascular disease, and previous history of stroke all increase a patients' risk for clot formation and stroke. These risk factors have been formulated into a scoring system called the CHA2DS2-VASc score. A score of greater than 2 on this scale indicates a moderate to high risk for clot formation and stroke. Anticoagulation medications are recommended in these patients. Non-traditional risk factors such as left atrial size and left ventricular hypertrophy have also been associated with increased stroke risk. These factors have not yet been routinely incorporated into treatment decisions regarding anticoagulation and stroke prevention.

This study is an expansion of an initial pilot conducted at Pen Bay Medical Center of patient records from 2014-2017. This pilot found 19 patients with a recorded stroke or TIA, history of atrial fibrillation, and CHA2DS2-VASc score of 2 or lower within that time period. This study will be an expansion of that pilot to include patient data from Maine Medical Center.

This study aims to look at these non-traditional risk factors in patients who have an otherwise low stroke risk based on the CHA2DS2-VASc score.

Our specific aims are:

1. Assess left atrial volume using volumetric measurements and left ventricular septal and posterior wall thickness from 2-D transthoracic echocardiography studies in patients with known atrial fibrillation who suffered a stroke or TIA. The investigator would then compare these data to control patients with atrial fibrillation with matched CHA2DS2-VASc scores, age (+/- 5 years), and gender who have no history of stroke or TIA. The goal is to identify higher risk patients with alternate anatomy who otherwise would be considered lower risk using traditional risk scoring methods. Identifying these individuals may lead to more aggressive interventions and subsequently may help in reducing the risk of stroke.
2. Assess stroke outcome as measured by NIH Stroke Scale and/or Modified Rankin Scale score, in the population of patients with atrial fibrillation who suffered a stroke to identify any potential differences associated with structural changes. If structural changes are associated with stroke severity, echocardiogram findings again may aid in guiding treatment decisions for patients with atrial fibrillation.