Post-Embolic Rhythm Detection With Implantable Versus External Monitoring

The overall aim of this trial is to determine the most cost effective approach to diagnose paroxysmal atrial fibrillation (PAF) following transient ischemic attack (TIA) and stroke. A summary of the rationale for this study is as follows: 1. Recently completed randomized trials of cardiac monitoring following stroke have established that PAF is more common than previously recognized in cryptogenic stroke. 2. The majority of TIA/stroke patients will have at least one potential stroke mechanism identified by the time etiologic investigations completed. 3. Detecting PAF in patients with strokes with known causes (eg. lacunar and large vessel atherosclerosis) is clinically important since appropriate anticoagulation for AF reduces stroke recurrence in all patients with prior TIA/stroke not just cryptogenic strokes. 4. There are competing technologies for evaluating cardiac rhythm and diagnosing AF but no cost effectiveness data 5. The rates of PAF in strokes with known causes (SKC) have not been well characterized. PER-DIEM is a pilot study to compare two different cardiac monitoring technologies as first-line investigations to detect PAF in patients with recent stroke and TIA. The study will also assess whether a pivotal trial is feasible and warranted. The principal research questions to be addressed in this study will be: 1. Whether implantable loop recorder (ILR) plus remote monitoring will diagnose more paroxysmal AF / atrial flutter and provide a better assessment of the total burden of AF resulting in a greater proportion of patients started on an OAC versus the external loop recorder (ELR) strategy. 2. What is the relative cost-effectiveness as a first-line investigation of long-term implantable ECG (ILR) coupled with remote monitoring for 12 months compared to external event-triggered ECG loop recorder (ELR) for 30 days in the diagnosis clinically actionable AF in following TIA/stroke. 2\) What is the feasibility, patient compliance, diagnostic accuracy a