SALT LAKE CITY, UTAH. Several studies have observed a direct correlation between atrial fibrillation and elevated value for the inflammation marker hs-CRP (high-sensitivity C-reactive protein). This correlation applies to both lone afibbers and afibbers with underlying heart disease. There is also evidence that permanent afibbers tend to have higher CRP values than persistent afibbers who, in turn, have higher values than paroxysmal afibbers.
A study of 5000 healthy individuals without afib found that CRP values varied between 0.01 mg/dL (0.1 mg/L) and 0.38 mg/dL (3.8 mg/L) with a median of 0.16 mg/dL (1.6 mg/L). A CRP value above 0.38 mg/dL (3.8 mg/L) is generally considered a sign of a systemic inflammation. There is also evidence that a high CRP value increases the risk of ischemic stroke.
Researchers at the Mayo Clinic and the University of Utah School of Medicine have now quantified the relationship between CRP and stroke risk. They correlated CRP results from 2340 patients with suspected coronary artery disease (CAD) with the patients' CHADS2 score. The CHADS2 score is an estimate of the risk of ischemic stroke in which congestive heart failure, hypertension, age over 75 years, and diabetes are each assigned a point score of 1, while having experienced a stroke or a transient ischemic attack (TIA) is assigned a point score of 2.
The study group included 3288 patients who underwent coronary angiography for suspected CAD. Of these, 61% did indeed have CAD, 56% had hypertension, 19% diabetes, 15% congestive heart failure, and 2% had suffered a prior stroke or TIA. Ten percent of the group had atrial fibrillation (AF) who, on average, had a higher CRP level (14.0 mg/L or 1.4 mg/dL) than did study participants without AF (9.1 mg/L or 0.9 mg/dL). A higher CHADS2 score was found to be associated with a higher CRP value.