Update on the Management of Atrial Fibrillation in Older Adults

Hatim Al Lawati, MD, FRCPC, Cardiology Resident, Division of Cardiology, Faculty of Medicine, University of Toronto, Toronto, ON.
Fatemeh Akbarian, MD, Dermatologist, Research Fellow, University of Toronto, Toronto, ON.
Mohammad Ali Shafiee, MD, FRCPC, General Internist, Nephrologist, Department of Medicine, Toronto General Hospital, University Health Network; Clinician Teacher, University of Toronto, Toronto, ON.

Atrial fibrillation (AF) is by the far the most common cardiac rhythm disturbance encountered in clinical practice. It is associated with significant morbidity and mortality and has potentially lifelong implications in terms of therapy and complications. This disease is more commonly seen now given the increased life expectancy and the remarkable advances made in health care. The already at-risk older adult population is particularly vulnerable to complications from AF, especially embolic cerebrovascular events. This article reviews the evidence-based management of AF with a particular focus on the older adult population.
Key words: atrial fibrillation, older adults, stroke, rate control, rhythm control, stroke prophylaxis, anticoagulation.

Case
A 77-year-old man presented with hypertension and a previous right-middle cerebral artery ischemic stroke with mild residual left-sided motor weakness. He was found to have an irregular heartbeat, with a radial rate ranging between 90 and 110 beats per minute. His examination was remarkable for an irregularly irregular pulse with a blood pressure of 150/90 mm Hg. His transthoracic echocardiogram showed normal left ventricular systolic function with impaired relaxation consistent with diastolic dysfunction. His initial laboratory investigations including a thyroid profile were unremarkable. What is your approach to the management of this patient?

Background
Atrial fibrillation (AF) is commonly encountered in clinical practice, be it in an outpatient office setting or in the context of a busy inpatient service.¹ It is also the commonest arrhythmia encountered in a critical care unit and in the postoperative setting following cardiac and noncardiac surgeries. The incidence of AF in the community increases with age, approaching 8% in the population over 80 years of age.¹ Of note, the incidence has been on the rise, even after adjusting for age. This likely reflects a rising trend in the disease conditions associated with AF such as hypertensive heart disease. The condition is 1.5 times more commonly seen in males than in an age-matched female population.²

Advancing age is a well-recognized risk factor for stroke. About 75% of all strokes occur in individuals over 65 years of age. According to U.S. stroke data, the risk of having a stroke more than doubles for each decade over 55 years of age.³ Combining this with the increased risk of AF among older adults places this vulnerable segment of the population at a significantly increased risk of stroke, adding a growing burden to our health care system. In addition, the Framingham Heart Study showed that AF is an independent risk factor for death resulting in a 1.5- to 1.9-fold increase in mortality associated with systemic embolic events, cerebral embolic events, and heart failure.⁴

Due to the devastating implications of AF in the general population and the older adult population, in particular, a sound understanding of the management of AF and the evidence supporting it is of paramount importance to contemporary practitioners.

Classification and Etiology
The classification of AF follows the temporal pattern within which it is identified. It can be a single isolated or recurrent event. This is further classified into paroxysmal, with episodes that revert back to sinus rhythm within 7 days, typically in the first 48 hours in 60% of the cases; persistent, with episodes lasting longer than 7 days; and permanent, referring to episodes that last for more than a year, regardless of