Dear Dr. Roach: I am 83 and in great health, with mountain biking about four times a week and generally staying active. I had atrial fibrillation (AFib) at age 75, which appears to have abated after two ablations. This was confirmed by Holter monitoring for two weeks, then an additional week last year. Additionally, I don’t have any AFib symptoms.
However, I’m still on warfarin because I sustained a transient ischemic attack (TIA) for about half an hour several months ago after the monitoring had been completed. Ultrasound evaluations of my head and chest areas, as well as other tests, didn’t reflect the origin of this aberration. I don’t like taking warfarin. Would aspirin therapy be a viable alternative?
B.B.
Atrial fibrillation, a common abnormal heart rhythm, is a risk factor for stroke. Because of the lack of coordinated movement in the atria (fibrillation means the muscle is moving in a fast, chaotic and ineffective way, and the chamber does not pump blood into the ventricle), clots can form in the left atria and enter the brain, causing a blockage of blood flow to a specific area of the brain. Function can be recovered (a TIA) or not (stroke means cell death, although sometimes the brain can still recover function by having different parts of the brain take over the functions of the part that died).
An ablation aims to stop atrial fibrillation by using radio energy to damage the cells responsible for abnormal rhythm of the heart. The goal of treatment of atrial fibrillation is to remove symptoms and reduce stroke risk. Ablation can be successful at improving symptoms, but has not been proven to reduce stroke risk. People with risk factors for stroke should continue anticoagulation, such as with warfarin (Coumadin) or a newer medication, which doesn’t require blood monitoring.
It is common to have a few episodes of atrial fibrillation even after ablation, and they may be completely asymptomatic. Given the lack of other risk factors for your TIA, my best guess is that it was the AFib that caused the TIA.
Aspirin, an anti-platelet drug, is appropriate for some people with AFib at a low risk for stroke, but it is not as effective at reducing stroke as anticoagulation. Given your age and prior history of TIA, in my opinion, aspirin is not an appropriate alternative. You could consider a different oral anticoagulant, such as dabigatran (Pradaxa). Another option is a left atrial appendage occlusion, such as a Watchman device, which greatly (but not completely) reduces risk of stroke without medication. These devices are particularly useful for people at a higher risk for bleeding.
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