Chronic kidney disease and CHADS(2) score independently predict cardiovascular events and mortality in patients with nonvalvular atrial fibrillation

Chronic kidney disease is a risk factor for cardiovascular events, but how it relates to the prognosis associated with clinical risk factors for thromboembolism in patients with nonvalvular atrial fibrillation (AF) is not well known. Estimated glomerular filtration rate (eGFR), score for congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and stroke/transient ischemic attack (CHADS(2)), and clinical outcomes of cardiovascular events were determined in 387 patients with nonvalvular AF (mean age 66 years, 289 men, mean follow-up 5.6 ± 3.2 years). Decreased eGFR (<60 ml/min/1.73 m(2)) combined with CHADS(2) score ≥2 was associated with higher all-cause (12.9% vs 1.4% per year, hazard ratio [HR] 6.9, p <0.001) and cardiovascular (6.5% vs 0.2% per year, HR 29.7, p <0.001) mortalities compared to preserved eGFR (≥60 ml/min/1.73 m(2)) combined with CHADS(2) score <2. This was also true for rates of cardiac events (cardiac death, nonfatal myocardial infarction, or hospitalization for worsening of heart failure, 10.4% vs 1.3% per year, HR 8.9, p <0.001), ischemic stroke (3.6% vs 0.2% per year, HR 11.0, p <0.001), and cardiovascular events (cardiac events and ischemic stroke, 13.6% vs 1.5% per year, HR 8.3, p <0.001). On multivariate analysis, CHADS(2) score ≥2, decreased eGFR, and male gender independently predicted all-cause mortality. In conclusion, combined eGFR and CHADS(2) score could be an independent powerful predictor of cardiovascular events and mortality in patients with nonvalvular AF. Long-term mortality, cardiac events, and stroke risk were >8 times higher when decreased eGFR (<60 ml/min/1.73 m(2)) was present with higher CHADS(2) score (≥2).