Comparison between CHADS2 and CHA2 DS2 -VASc score in a stroke cohort with atrial fibrillation

Abstract

Background and purpose: In patients with atrial fibrillation (AF), stroke risk stratification schemes have been developed to optimize antithrombotic treatment. The CHADS(2) score is frequently used but has limitations. The CHA(2) DS(2) -VASc score improves risk prediction. Our objectives are to describe CHADS(2) and CHA(2) DS(2) -VASc score distribution in a cohort of patients with AF and first-ever ischaemic stroke (FIS) and to identify differences in embolic risk stratification.

Methods: Our cohort included 589 patients with FIS, previous modified Rankin score ≤ 3, and non-valvular AF. We recorded demographic data, vascular risk factors, and antithrombotic pre-treatment. The CHADS(2) and CHA(2) DS(2) -VASc scores were calculated according to clinical status before stroke onset.

Results: In 186 (31.6%) patients, AF was previously unknown. Of patients with known AF and CHADS(2) ≥ 2 (n=320), only 103 (32.2%) were taking anticoagulants; more than half of these patients had an INR <2. The CHADS(2) score placed 142 (24.1%) patients in the low-intermediate risk (score ≤ 1) category compared with 21 (3.6%) with CHA(2) DS(2) -VASc, P < 0.001. Applying CHA(2) DS(2) -VASc reclassified 121 (85.2%) subjects in the CHADS(2) low-intermediate risk category as high risk (≥ 2), an indication for anticoagulants. Of the 21 patients who suffered a stroke despite their low CHA(2) DS(2) -VASc score (≤ 1), seven (33.3%) reported alcohol overuse, and six (28.5%) had a concomitant stroke etiology.

Conclusions: About 25% of FIS patients with AF had a CHADS(2) score ≤ 1. Despite the high CHADS(2) score of our population, few patients received the recommended antithrombotic treatment according to their thromboembolic risk. Using the CHA(2) DS(2) -VASc schema significantly increased the percentage of patients indicated for anticoagulation.