Chapter 30: Left Atrial Appendage Closure

PATIENT CASE

An 84 year-old woman with hypertension, chronic obstructive pulmonary disease, and chronic renal insufficiency (estimated glomerular filtration, rate 38 mL/min/1.73 m²) also has paroxysmal atrial fibrillation (AF) with a CHADS₂ score of 4 and CHA₂DS₂-VASc score of 6. She suffered a stroke a year ago and was treated with tissue plasminogen activator. This was complicated by hemorrhagic transformation, resulting in expressive dysphagia. Given her history of intracranial hemorrhage, she was deemed to be a poor candidate for long-term oral anticoagulation (OAC) and was thus referred for endovascular left atrial appendage (LAA) closure. Under general anesthesia and transesophageal echocardiography (TEE) guidance, a 28-mm Amplatzer Cardiac Plug (ACP; St. Jude Medical, St. Paul, MN) was successfully deployed. The patient was discharged the following day with no complication and was commenced on dual antiplatelet therapy (aspirin 81 mg/d and clopidogrel 75 mg/d) for 3 months, followed by aspirin indefinitely.

ATRIAL FIBRILLATION

AF is the most common cardiac arrhythmia. It affects 1% of the general population, 6% of people over the age of 65 years, and 9% of people over the age of 80 years.^1,2 With the aging population, the prevalence of AF is set to increase, and its impact on the health system is also projected to increase substantially.^3,4

AF is associated with considerable morbidity and mortality. One of the major feared morbidities associated with AF is stroke. AF is an independent risk factor for stroke, occurring in up to 19% of stroke patients over the age of 70 years.⁵ After adjusting for other risk factors, AF is associated with a 4- to 5-fold increased risk of ischemic stroke.⁵ Paroxysmal AF carries a similar risk of stroke as patients with permanent AF.⁶ Cardioembolic strokes associated with AF are generally more severe than other types of ischemic stroke and have been associated with higher 30-day and 1-year mortality.^7,8 The CHADS₂ and the CHA₂DS₂-VASc were developed as risk models to estimate risk of stroke (Tables 30-1 and 30-2) and are widely adopted in clinical practice. It is estimated that there are 800,000 strokes each year in the United States, with 1.5% of those attributed to AF in those under age 59 and 23% attributed to AF in those greater than age 80.⁵ Stroke is the number 1 cause of major morbidity in the United States and estimated to cost the healthcare system approximately $30 billion each year.