Limitations of CHADS2 scoring system in predicting stroke risk--need to change the age criteria.

INTRODUCTION Atrial fibrillation (AF) is the most common arrhythmia with a strong association with age. The aim of this study was to evaluate the rate of stroke in relation to age and anticoagulation status based on CHADS2 risk criteria. METHODS This study included all patients with non-valvular atrial fibrillation admitted to our clinic between 1/11/2007 and 1/11/2009, with minimum one year follow up for patients without stroke. We calculated risk based on CHADS2 (C-cardiac failure, H- hypertension, A-age >75 years, D-diabetes mellitus, S-stroke) point system and evaluated anticoagulation status at the moment of first occurrence of stroke. We observed the rate of stroke in different group age. RESULTS The average of participants with AF was 67.9 +/- 10.3 years. Amongst 302 patients with non-valvular atrial fibrillation, 32.5% had been anticoagulated while 13.9% of experienced stroke. The stroke were more present in patients who used aspirin in age group 65-74 (22.5%, P = 0.014). The mean age of patients who experienced stroke were 67.2, SD +/- 10.8 vs. 71.6, SD +/- 5.1, P = 0.000. Of the patients with stroke from age group 65-74 years, 23 were in CHADS2 0-1 scoring system. CONCLUSION The higher rate of stroke was in the 65-74 years age group, with CHADS2 scoring system 0-1, and without anticoagulation therapy. Therefore modification has to be considered for the CHADS2 scoring system to account the age as a risk factor for population in different regions.