Left Atrial Imaging Prior to Cardioversion: Leveraging Computed Tomography to Rule Out Thrombus in The Emergency Department (LA CLOTTED)

N/ANot Yet RecruitingNCT07002450

Ottawa Heart Institute Research Corporation190 enrolled

Overview

The goal of this randomized clinical trial is to learn whether patients with symptomatic atrial fibrillation or atrial flutter (AF) who require heart imaging to rule out a blood clot before cardioversion would benefit from cardiac computed tomography angiography (CCT) in the emergency department (ED) compared to current standard of care management. This will be a multicenter trial evaluating whether CCT-facilitated cardioversion in the ED reduces hospital admission, reduces repeat presentations to hospital and improves patient quality of life compared to the current standard of care. Participants will undergo CCT-facilitated cardioversion or be treated according to current standard of care while in the ED and complete quality of life questionnaires in the ED and follow-up at 30 days.

Atrial fibrillation and atrial flutter (AF) are the most common cardiac arrhythmias worldwide resulting in frequent visits to the emergency department (ED). Some patients can undergo chemical or electrical cardioversion to restore their heart back to a sinus rhythm. However, if a patient is not on blood thinners and the duration of AF is prolonged then blood clots may form in the heart increasing the risk of stroke after cardioversion. Therefore, some patients must undergo heart imaging to rule out any blood clots before cardioversion is considered safe. Transesophageal echocardiography (TEE) is commonly used to rule out blood clots, but it is not readily available in all EDs often resulting in hospital admission to facilitate this test or deferring cardioversion until 3 weeks of blood thinners have been completed. Cardiac computed tomography angiography (CCT) is a more readily available alternative to TEE that can be done rapidly in the ED. CCT has excellent sensitivity and specificity compared to TEE for identifying cardiac thrombus. If there is no thrombus detected on the CCT then patients could be immediately cardioverted to sinus rhythm thus avoiding an unnecessary hospital admission and reducing the symptom burden associated with remaining in AF. This study is a multicenter randomized trial that will evaluate the effectiveness of using CCT facilitated cardioversion in the ED compared to current standard of care management.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

Interventions

Cardiac computed tomography angiographyDIAGNOSTIC_TEST

Patients will undergo CCT according to the following protocol. A non-contrast enhanced prospective ECG-triggered image will be acquired followed by a contrast-enhanced prospective ECG-triggered image using a tri-phasic contrast protocol. Delayed CT images 60 seconds after the initial contrast-enhanced CT scan will be obtained. Cardiac CT image interpretation will be performed according to routine clinical practices in a pragmatic fashion. The LA will be assessed for filling defects and characterized based upon attenuation values. If LA thrombus cannot be excluded, filling defects will be assessed on the delay images. Increases in attenuation would be consistent with pseudo-thrombus from 'slow flow' and 'incomplete opacification'. Areas where attenuation does not change significantly (persistent filling defect) will be diagnosed as thrombus. If the CCT shows no LA thrombus then the ED physician will be able to perform electrical and/or chemical cardioversion at their discretion.

Standard of care managementOTHER

Patients in the standard of care arm may undergo any combination of the following management strategies in the emergency department (ED) at the discretion of their treating physician: 1\. Transesophageal echocardiogram (TEE) facilitated cardioversion; 2. Rate control; 3. Consultation with inpatient cardiac specialist for assessment/management and consideration of hospital admission; 4. cardioversion after 3 weeks of anticoagulation; and/or 5. Outpatient referral to cardiac specialist or general practitioner for further management.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Age ≥18 years old; and 2. Primary symptomatic AF without a reversible underlying cause (e.g. sepsis, pneumonia, pulmonary embolism, hyperthyroidism) 3. LA imaging required before cardioversion according to local clinical practice guidelines Exclusion Criteria: 1. Patients with an indication for emergency cardioversion (e.g. hemodynamic instability (systolic blood pressure\<90mmHg or signs of shock), cardiac ischemia (ongoing severe chest pain or marked ST depression on ECG \>2mm), or pulmonary edema (significant dyspnea, crackles, or hypoxia)); or 2. Contraindication to CCT (renal insufficiency (eGFR\< 45ml/min/1.73m2), allergy to intravenous contrast agents, pregnancy (contraindications to radiation exposure), or inability to perform 20-second breath-hold)

Outcomes

Primary Outcomes

Primary composite outcome

Using a hierarchical win ratio: 1. All-cause death 2. Stroke, transient ischemic attack, or systemic embolism 3. Admission to hospital for a cardiac reason (ex. heart failure, syncope, palpitations/arrhythmia, angina or acute coronary syndrome) 4. Number of repeat presentations to hospital for a cardiac reason (ex. heart failure, syncope, palpitations/arrhythmia, angina or acute coronary syndrome) 5. Improvement in AF Effect On Quality-Of-Life Questionnaire (AFEQT) quality of life greater than or equal to 5 points 6. Presence of sinus rhythm at 30 days