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 and rates of AF detection (>30 seconds) of ILR compared to the ELR strategies.

Inclusion Criteria:

• Diagnosis of the index event* made by a stroke specialist of an acute ischemic stroke or TIA occurring within the previous 90 days. The event must be either:

  1. an arterial ischemic stroke confirmed by neuroimaging; or
  2. transient ischemic attack with diffusion weighted positive lesion on MRI

• At least one 12-lead ECG has already been obtained as part of the routine clinical post-stroke/TIA work-up, and no ECGs have shown any episodes of atrial fibrillation or atrial flutter

• The patient is being actively investigated for the etiology of the stroke/TIA event and additional cardiac monitoring is desired to screen further for the possibility of occult paroxysmal atrial fibrillation/flutter

• Age 18 years or older

• Informed consent from the patient

• The patient is expected to survive at least 6 months.

Exclusion Criteria:

• Any previously documented atrial fibrillation or atrial flutter, i.e. a past history of atrial fibrillation/flutter or atrial fibrillation/flutter detected on ECG, Holter, or telemetry following the index stroke/TIA event (a remote history of transient perioperative atrial fibrillation is not exclusionary)
• Planned carotid endarterectomy or carotid artery stenting within 90 days
• Any condition for which there is already an indication for long term anticoagulation Pacemaker or implantable cardioverter defibrillator device
• Work-up for stroke that has already included extended (>48 hour) external ECG (excluding telemetry)
• Stroke and/or comorbid illness will prevent completion of planned follow-up assessments

12 months

A clinical events committee reviewed all serious adverse events 12 months after study initiation to ensure that neither group had a disproportionate accumulation of adverse events. The study used approved devices therefore nonserious adverse events were not tracked.