Outcomes in AF, atrial flutter may vary by stroke risk score
While people with atrial fibrillation or atrial flutter had worse outcomes than people without either, for some outcomes, risk varied by degree of CHA2DS2-VASc score, researchers reported in JAMA Network Open.
The researchers conducted a nationwide cohort study using data from the Taiwan National Health Insurance Research Database between 2001 and 2012. The population included 188,811 patients with AF (mean age, 74 years; 56% men), 6,121 patients with atrial flutter (mean age, 68 years; 61% men) and 24,484 controls without either condition matched by age and sex (mean age, 67 years; 61% men).
Participants were stratified by CHA2DS2-VASc score; patients with AF had a higher mean CHA2DS2-VASc score than patients with atrial flutter or controls. Outcomes of interest included ischemic stroke, hospitalization for HF and all-cause mortality.
After stratification by CHA2DS2-VASc score, incidence densities for all three outcomes were higher in the AF group vs. the control group, Yu-Sheng Lin, MD, from the division of cardiology, department of internal medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan, and colleagues wrote.
For ischemic stroke, the incidence densities were as follows: 3.08 per 100 person-years in the AF cohort (95% CI, 3.03-3.13), 1.45 per 100 person-years in the atrial flutter cohort (95% CI, 1.28-1.62) and 0.97 per 100 person-years in controls (95% CI, 0.92-1.03).
For HF hospitalization, the incidence densities were as follows: 3.39 per 100 person-years in the AF cohort (95% CI, 3.34-3.44), 1.57 per 100 person-years in the atrial flutter cohort (95% CI, 1.39-1.74) and 0.32 per 100 person-years in controls (95% CI, 0.29-0.35).
For all-cause mortality, the incidence densities were 17.8 per 100 person-years in the AF cohort (95% CI, 17.7-17.9), 13.9 per 100 person-years in the atrial flutter cohort (95% CI, 13.4-14.4) and 4.2 per 100 person-years in controls (95% CI, 4.1-4.4).
Compared with controls, the atrial flutter cohort had consistently higher incidences of HF hospitalization and all-cause mortality across CHA2DS2-VASc scores, but incidence of ischemic stroke was higher for atrial flutter cohort only if the CHA2DS2-VASc score was 5 to 9, Lin and colleagues wrote.
Compared with the atrial flutter cohort, the AF cohort had higher incidence of ischemic stroke and HF hospitalization when the CHA2DS2-VASc score was 1 or higher, but for all-cause mortality, the difference was only significant if the CHA2DS2-VASc score was 1 to 3, according to the researchers.
“Our study suggests that further research should be done to reevaluate the net clinical benefit of oral anticoagulants to prevent ischemic stroke in patients with [atrial flutter] according to the currently recommended level of the CHA2DS2-VASc score,” Lin and colleagues wrote. – by Erik Swain
Disclosure: The authors report no relevant financial disclosures.