CHADS-VASc scores and Intermountain Mortality Risk Scores for the joint risk stratification of dementia among patients with atrial fibrillation.

Background: High CHADS-VASc scores in atrial fibrillation (AF) patients are generally associated with increased risks of stroke and dementia. At lower CHADS-VASc scores, there remains an unquantifiable cranial injury risk, necessitating an improved risk assessment method within these lower-risk groups.

Objective: The purpose of this study was to determine whether sex-specific Intermountain Mortality Risk Scores (IMRS), a dynamic measures of systemic health that comprises commonly performed blood tests, can stratify dementia risk overall and among CHADS-VASc score strata in AF patients.

Methods: Female (n = 34,083) and male (n = 39,998) AF patients with no history of dementia were studied. CHADS-VASc scores were assessed at the time of AF diagnosis and were stratified into scores of 0-1, 2, and ≥3. Within each CHADS-VASc score stratum, patients were further stratified by IMRS categories of low, moderate, and high. Multivariable Cox hazard regression was used to determine dementia risk.

Results: High-risk IMRS patients were generally older and had higher rates of hypertension, diabetes, heart failure, and prior stroke. Higher CHADS-VASc score strata (≥3 vs ≤1: women, hazard ratio [HR] 7.77, 95% confidence interval [CI] 5.94-10.17, P < .001; men: HR 4.75, 95% CI 4.15-5.44, P < .001) and IMRS categories (high vs low: women, HR 3.09, 95% CI 2.71-3.51, P < .001; men, HR 2.70, 95% CI 2.39-3.06, P < .001) were predictive of dementia. When stratified by CHADS-VASc scores, IMRS further identified risk in each stratum.

Conclusion: Both CHADS-VASc scores and IMRS were independently associated with dementia incidence among AF patients. IMRS further stratified dementia risk among CHADS-VASc score strata, particularly among those with lower CHADS-VASc scores.