Abstract 17228: Not So Fast: Ischemic Stroke Risk in Atrial Fibrillation in the Era of New Hypertension Guidelines.

Introduction: Atrial fibrillation (AF) is the most common cardiac arrhythmia, with an estimated prevalence in the US of up to 6.1 million people in 2014. The CHA2DS2-VASc score is a widely used tool to help stratify ischemic stroke risk and guide decision-making regarding anticoagulation in AF based on multiple clinical risk factors including a history of hypertension. While the CHA2DS2-VASc score has been validated using the prior definition of hypertension (≥140/≥90 mmHg), the 2017 ACC/AHA guidelines define hypertension as ≥130/≥80 mmHg. It is unclear what clinical impact this change will have on the use and validity of CHA2DS2-VASc scoring and risk/benefit of anticoagulation for prevention of thromboembolic stroke. In order to estimate this impact, we performed a statistical analysis of the NHANES III database. Methods: The Third National Health and Nutrition Examination Survey (NHANES III), a nationwide probability survey of 39,695 persons conducted from 1988-1994, was used as a representative sample of the general US population. AF was defined as the presence of AF on ECG or the presence of an irregular pulse on physical exam along with the absence of documented sinus rhythm on ECG. Results: We identified 278 patients with AF, with a weighted value representing 2.58 million people. Using the prior hypertension guidelines, 181 patients (weighted value 1.07 million) had a CHA2DS2-VASc score of ≥2 and qualified for anticoagulation. With the new hypertension guidelines, 200 patients qualified for anticoagulation (weighted value 1.33 million). This represents a 10.5% increase in the number of patients with atrial fibrillation requiring anticoagulation (weighted value 250,000). Conclusions: Incorporation of the 2017 ACC/AHA hypertension definitions into the CHA2DS2-VASc score results in a 10.5% increase in patients who would require anticoagulation from a representative sample of the US population (NHANES III). Clinical risk/benefit for CHA2DS2-VASc scoring and anticoagulation using this definition for hypertension has not been validated. To avoid potentially unnecessary anticoagulation in AF, clinicians should consider using the ≥140/≥90 mmHg definition for hypertension upon which the CHA2DS2-VASc scoring is validated. [ABSTRACT FROM AUTHOR]