Early Diagnosis of Atrial Fibrillation in the Wait-Time Prior to Seeing a Cardiologist (CATCH-AF)

Wait-times from referral by a family practitioner to seeing a specialist have increased greatly over the past 10 years in Canada. The Fraser institute reports an 11 week wait-time in BC in 20161. Our experience is that this is representative of the wait-time to see a cardiologist at our institute.

Family doctors can diagnose some cases of atrial fibrillation (AF) with a pulse check and 12-lead electrocardiogram (ECG). However this is the minority of patients and most diagnoses are made on the basis of more prolonged ambulatory ECG recordings as part of the investigation of paroxysmal symptoms by a specialist2.

There is an increasing prevalence of AF3 and the consequences of late diagnosis can be dire. For example a 76 year old lady with treated hypertension and yet to be diagnosed paroxysmal AF has a risk of 6.7% per year of suffering stroke, TIA or systemic thromboembolus4. During the ~11 week wait for an appointment plus a further ~8 week wait for thorough diagnostic testing and further follow up she therefore has a 2.5% risk of having an event. If this is multiplied across the thousands of patients waiting for appointments across Canada over the course of a year it is evident that numerous thromboembolic complications could be prevented through reduction of the time to diagnosis.

Furthermore the first-line investigation for diagnosis of paroxysmal arrhythmia is usually an ambulatory ECG monitor (Holter/Event monitor)5,6. However, patients frequently do not have symptoms during the period of monitoring and the diagnostic yield is between 15% and 39%7-10.

Implantable loop recorders (ILRs) can provide accurate and thorough ECG monitoring continuously for up to 3 years. However, they are used late in the diagnostic process and are too expensive for widespread use for AF screening and so can only have a limited impact on overall time to diagnosis.