Allison E. Arch, MD

Rizos T, Horstmann S, Dittgen F, Täger T, Jenetzky E, Heuschmann P, et al. Preexisting Heart Disease Underlies Newly Diagnosed Atrial Fibrillation After Acute Ischemic Stroke. Stroke. 2016

Atrial fibrillation (afib) is a risk factor for ischemic stroke. In patients who just had a stroke, a proportion of them will be diagnosed with afib in the post-stroke period. Does afib diagnosed immediately after a stroke carry the same risk for future stroke as afib that was already a known diagnosis? Is it associated with cardiovascular disease, or does the stroke itself cause a neurogenic arrhythmia that may not portend the same future stroke risk? These are the questions that Rizos and colleagues addressed in their single center observational study.

The authors included 1,397 stroke patients who were entered into a prospective database. In the 320 patients who had afib recorded in the hospital, 64% had a known diagnosis of afib. The remaining 36% had a new diagnosis of afib. Comparing those with known afib to those newly diagnosed, both groups had the same amounts of coronary artery disease, left atrial dilation, and low ejection fractions on echocardiogram. In other words, the newly diagnosed afib group had the same cardiovascular profile as the known afib group. Therefore, patients with new afib and stroke may just have afib due to underlying cardiovascular disease, and not from neurogenic strain on the heart.

This has implications for secondary stroke prevention. Whether or not atrial fibrillation was a known or a new diagnosis at the time of ischemic stroke, Rizos and colleagues show that both groups have the same underlying cardiovascular risk profile. Therefore, one may conclude that both groups should undergo the same stroke secondary prevention strategies.