[Predicting embolic events in patients with nonvalvular atrial fibrillation: evaluation of the CHADS2 score in a Mediterranean population].

INTRODUCTION AND OBJECTIVES A new index for predicting embolic risk in nonvalvular atrial fibrillation has been proposed, the CHADS2 score, which is calculated by adding 1 point each for the presence of congestive heart failure, hypertension, age 75 years or older, and diabetes, and by adding 2 points for a history of stroke or transient ischemic attack (TIA). Our objective was to evaluate the use of this score in a Mediterranean population. METHODS Between February 1st, 2000 and December 20th, 2006, all patients with permanent nonvalvular atrial fibrillation being treated at two outpatient cardiology clinics in a university hospital in the south of Spain were offered antithrombotic therapy in accordance with scientific society recommendations and were prospectively monitored for embolic events (i.e., stroke, TIA or peripheral embolism). A CHADS2 score was derived for each of the 296 patients who did not receive anticoagulation. RESULTS The CHADS2 score was 0 in 69 (23.3%) patients, 1 in 81 (27.4%), 2 in 99 (33.4%), 3 in 30 (10.1%), and 4 or more in 17 (5.7%). After 21 (17) months of follow-up, the embolic event rates for CHADS2 scores of 0, 1, 2, 3, and > or =4 were 2.88, 5.80, 5.16, 14.78 and 22.02 per 100 patient-years, respectively (P=.0016). Patients with a CHADS2 score from 0-2 had an embolic rate of 4.63 per 100 patient-years, compared with 17.31 per 100 patient-years in those with a score > or =3 (P=.00087). CONCLUSIONS The CHADS2 score proved useful for quantifying the risk of an embolic event in Mediterranean patients with nonvalvular atrial fibrillation. In our series, the risk of embolism in patients with a low score was not negligible.