By Matthew E. Fink, MD
Professor and Chairman, Department of Neurology, Weill Cornell Medical College; Neurologist-in-Chief, New York Presbyterian Hospital
Dr. Fink reports he is a retained consultant for Procter & Gamble and Pfizer.
SOURCE: Lin YS, Chen YL, Chen TS, et al. Comparison of clinical outcomes among patients with atrial fibrillation or atrial flutter stratified by CHA2DS2-VASc score. JAMA Network Open 2018;1:e180941. doi:10.1001/jamanetworkopen.2018.0941.
Atrial flutter (AFL) and atrial fibrillation (AF) often are grouped together in terms of risk stratification for ischemic stroke. Risk and decisions regarding institution of antithrombotic therapy have relied heavily on the use of a scoring system known as CHADS. The CHA2DS2-VASc scoring system was developed in 2010 and calculates according to a point system (possible score range, 0-9) in which two points are assigned for history of stroke/transient ischemic attack and age > 75 years; one point is assigned for age 65-74 years, a history of congestive heart failure, hypertension, diabetes, vascular disease, and female sex. A high score indicates an increased risk of ischemic stroke and often results in treatment with antithrombotic therapy. However, it is uncertain if risks in patients with AFL are similar to the risks in patients with AF. Lin et al conducted this study to analyze the incidence of ischemic stroke, hospitalization for heart failure, and all-cause mortality as it relates to the calculation of the CHADS score comparing patients with AF and AFL.
Data were analyzed from a nationwide database of the Taiwan National Health Insurance Research Database with information collected from 1997 through 2012, encompassing 23 million Taiwan residents. Patients with AF and AFL were paired with age- and sex-matched controls. There were 188,811 patients in the AF cohort and 6,121 patients in the AFL cohort, with 24,484 patients in the matched-control cohort. The patients with AF tended to be older, were more predominantly female, and had higher CHA2DS2-VASc scores than the patients with AFL and control participants. After stratification by CHA2DS2-VASc score, the incidence of ischemic stroke, heart failure hospitalization, and all-cause mortality were significantly higher in the AF cohort than in the matched-control cohort. In comparing the AFL cohort to matched controls, the incidences of heart failure and all-cause mortality were significantly higher, but ischemic stroke was higher only in patients who had a CHA2DS2-VASc score of 5 to 9. In the AF cohort, the incidence of ischemic stroke was significantly higher at a CHA2DS2-VASc score of 1 or higher. The authors of this well-designed study found significantly different clinical outcomes between patients with AFL and AF, and the significance of the CHA2DS2-VASc score in predicting stroke may be different when applied to AFL patients vs. AF patients.
