CHA2DS2-VASC and CHADS2 Scores Predict Adverse Clinical Events in Patients With Pacemakers and Sinus Node Dysfunction Independent of Atrial Fibrillation

Background: CHA(2)DS(2)-VASc and CHADS(2) scores were derived and validated for stroke-risk stratification in patients who have a diagnosis of atrial fibrillation (AF). We hypothesized that these scores would predict adverse cardiovascular events even in the absence of AF. Methods: The CHA(2)DS(2)-VASc and CHADS(2) scores for 2010 patients with sick sinus syndrome who underwent pacemaker implantation and were enrolled in the Mode Selection Trial (MOST) were calculated. The association of these risk scores with main trial end points, including the composite of death and stroke, were evaluated to determine whether the associations differed by history of AF. Results: Of the 2010 patients, 12% had a CHA(2)DS(2)-VASc score of 0-1, 16% had a score of 2, 41% had a score of 3-4, and 31% had a score >= 5 (the distribution for CHADS(2) was similar); 42% had a clinical history of AF. Both scores were associated with death or stroke (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.05-1.23 for each 1-point increase in CHA(2)DS(2)-VASc; P = 0.001; HR, 1.11; 95% CI, 1.02-1.21 for each 1-point increase in CHADS(2); P = 0.016). Association of scores with outcomes of death, stroke, and heart failure hospitalization were not different for patients with vs those without a history of AF (interaction P >= 0.55 for CHA(2)DS(2)-VASc and >= 0.30 for CHADS(2)). Conclusions: Both CHA(2)DS(2)-VASc and CHADS(2) scores predict risk of death or stroke in patients with sick sinus syndrome, regardless of AF history. These scores could be risk-stratification tools for clinical events that might respond to new therapies-ie, anticoagulation or other interventionsdeven in the absence of AF.