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Abstract
Background and Purpose– High sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation, is a predictor of cardiovascular events in the general population. We compared the association between hs-CRP level and subsequent stroke events in in individuals with and without atrial fibrillation (AF) in the REGARDS study.
Methods – A total of 27, 609 participants (40% African American, 54% female, age> 45 years) of whom 2,408 had AF were included in this analysis. Stroke cases were identified and adjudicated during 8.3 years follow up (median 5 years). AF was ascertained by electrocardiogram or self- reported history of previous physician diagnosis. Cox proportional hazard analysis was used to examine the risk of stroke in study participants with and without AF, separately.
Results– Median hs-CRP was 2.7 mg/L (IQR: 5.0) in the AF group and 2.2 mg/L (IQR: 4.0) in the group without AF (p log hs-CRP <0.01). Stroke free survival curves in AF population with hs-CRP less vs. greater than 3mg/L was not statistically significant (p 0.78) but appeared significant in those without AF (p<0.01). In a model adjusted for demographics, traditional stroke risk factors, and warfarin use, one unit change in hs-CRP was associated with subsequent stroke in the participants without AF (HR 1.01 95%CI 1.01, 1.02) but not in those with AF (HR 1.00 (95% CI 0.97-1.02).
Conclusions– In the REGARDS study, hs-CRP was significantly associated with stroke risk in population without AF but not in those with AF. These findings suggest a limited value of hs-CRP in improving stroke risk stratification in patients with AF.
