Risk Factors That Contribute to the Maintenance of Sinus Rhythm

Study Overview
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Brief Summary
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This is a prospective clinical research study. The objective of this study is to evaluate if clinical risk factors as well as structural features on echocardiography affect the maintenance of sinus rhythm after electrical cardioversion at 30 days. The investigators anticipate 140 patients to be enrolled in the study.

Detailed Description
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Atrial fibrillation is the most commonly diagnosed arrhythmia in the United States. A systematic review of worldwide population-based studies estimated that approximately 33 million people were diagnosed with atrial fibrillation in 2010. The prevalence of atrial fibrillation in the United States increases with advancing age. Approximately 1% of patients with atrial fibrillation are under 60 years of age whereas more than one-third are over 80 years of age. Although atrial fibrillation is commonly diagnosed and continues to have increased incidence in the country, patients continue to be admitted to the hospital for worsening symptoms of chest pain, shortness of breath, and palpitations. Long-term complications of atrial fibrillation include cardiomyopathy, cerebrovascular events, thromboembolic events, and death. Many medications have been established to convert patients from atrial fibrillation to normal sinus rhythm; however procedures of cardioversion and ablation have also proven to be effective. A study, the AFFIRM trial, published in the New England Journal of Medicine in 2002 discussed the benefit of converting patients to sinus rhythm versus keeping patients in atrial fibrillation, however making sure their heart rates were well-controlled. This study did not demonstrate a significant difference in death, ischemic stroke, or major bleeding in both treatment arms suggesting there is no benefit of converting patients from atrial fibrillation to normal sinus rhythm. However, with increasing health costs occurring around the country, every effort should be made to help improve patient symptoms and avoid unnecessary hospitalizations. A study published in the Journal of American College of Cardiology in 2004, Effect of rate or rhythm control on quality of life in persistent atrial fibrillation: Results from the Rate Control Versus Electrical Cardioversion (RACE) study, concluded that the quality of life was impaired in patients with atrial fibrillation. Another study published in 2012, Economic Burden of Atrial Fibrillation: Implications for Intervention, reported total costs of atrial fibrillation care in the United States to be estimated to be $6.65 billion per year. Our study is designed to look at patients with atrial fibrillation who underwent electrical cardioversion to restore sinus rhythm and create a prediction model to identify specific risk factors, which may contribute to persistent atrial fibrillation. Prediction models have been established in regards to maintaining sinus rhythm, including the Hatch Score, which examined risk factors of hypertension, history of TIA or stroke, chronic obstructive pulmonary disease, and heart failure that predisposed patients to persistent atrial fibrillation. Another score established was the LADS score, which observed risk factors of left atrial diameter, age, history of stroke, and smoking status as predictors of persistent atrial fibrillation. The purpose of our study is to create a new prediction model using clinical and echocardiographic parameters to determine if these factors will predict persistent atrial fibrillation after electrical cardioversion. Transesophageal echocardiographic parameters include imaging of the left atrial appendage (LAA) and calculating the LAA ejection fraction (LAAEF) by 3D or biplane Simpson method (based on image quality), and using pulse-wave Doppler to calculate the LAA exit velocity and S/D ratio across the pulmonic vein. Transthoracic echocardiographic parameters include estimated pulmonary arterial pressure (PASP) using tricuspid regurgitation (TR) jet velocity, left atrial volume index (LAVi), left ventricular (LV) size, LV hypertrophy (LVH) and left ventricular ejection fraction (LVEF).

Official Title
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Risk Factors That Contribute to the Maintenance of Sinus Rhythm: A Prospective Study to Create a Prediction Model for Atrial Fibrillation Patients to Maintain Sinus Rhythm.

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Other: Standard Care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age >18 years Documented atrial fibrillation by electrocardiogram (ECG) Patients undergoing electrical cardioversion for atrial fibrillation Patients with a baseline transthoracic echocardiography within 1 month prior to the cardioversion Exclusion Criteria: Patients who did not convert to normal sinus rhythm after electrical cardioversion Patients who are found to have a LAA thrombus on TEE Patients who do not have a follow up ECG

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Control Group<br>Patients will be scheduled for an electrocardiogram thirty days after their electrical cardioversion. Based on the electrocardiogram result, patients that maintained sinus rhythm will be assigned to Control. | Other: Standard Care<br>* Standard cardiovascular care<br>|
| Afib Group<br>Patients will be scheduled for an electrocardiogram thirty days after their electrical cardioversion. Based on the electrocardiogram result, patients that developed persistent atrial fibrillation will be assigned to Afib. | Other: Standard Care<br>* Standard cardiovascular care<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Transthoracic Echocardiography and Transesophageal Echocardiography findings | Left ventricular ejection fraction, left ventricular size, left ventricular hypertrophy, left atrial volume index, mitral valve early diastolic inflow velocity E, mitral valve tissue Doppler velocity e', E/e' ratio and pulmonary arterial pressure will be collected from transthoracic echocardiography findings in medical record. Left atrial size, left atrial appendage ejection fraction, left atrial appendage exit velocity, pulmonary venous flow with S/D ratio, and presence of spontaneous echo contrast will be collected from transesophageal echocardiography findings in medical record. Transthoracic Echocardiography and Transesophageal Echocardiography findings between participants that maintained sinus rhythm and participants that developed persistent atrial fibrillation will be compared to create a prediction model to identify specific risk factors, which may contribute to persistent atrial fibrillation. | 30 days post electrical cardioversion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Clinical risk factors | History of stroke/transient ischemic attack, hypertension, diabetes mellitus, congestive heart failure, coronary artery disease, pulmonary hypertension, chronic obstructive pulmonary disease, sleep apnea, hyperthyroidism, obesity, tobacco use, alcohol use, and home medications will be collected from medical record. | 30 days post electrical cardioversion |