Hussain, Nasir

Background: CHA2DS2-VASc score has been shown to predict occurrences of incident stroke in patients with history of atrial fibrillation (A-Fib)/ Flutter. However, data on whether if CHA2DS2-VASc score would predict incidence of stroke in patients without A-Fib/ Flutter is less clear. Methods: From 1993 through 2010, all patients undergoing a clinically indicated treadmill exercise test (TMET) at the Mayo Clinic, Rochester, MN were identified (N= 76,857). From this, Olmsted and neighboring counties residents were selected (N=14,095). From this, patients with age <18 years; prior history of valvular heart disease or A-Fib/ Flutter were excluded. Patient undergoing only Bruce or accelerated Naughton protocols on TMET were considered. Patients were stratified into 4 groups at baseline based on CHA2DS2-VASc score as determined at the time of TMET; group-0 score=0; group-I=1; group-2=2; group-3≥3. Patients were prospectively followed from the date of TMET until end of January 2016 for occurrence of incident stroke (ischemic and hemorrhagic). Stroke diagnosis was ascertained through retrospective chart review. Traumatic intracranial bleed was not considered. Proportional hazard regression modeling was done to assess relationship of CHA2DS2-VASc score with the stroke outcome while adjusting for METs achieved, sex, obesity, smoking status, and other relevant risk factors. Results: Final study population comprised of 12,624 patients with female comprising 37% of the cohort. Mean age in our study group was 52.2 ± 12.8 years. During an overall median follow-up of 14 (8 to 17) years, 1,255 (9.9%) patients developed incident stroke. While using CHA2DS2-VASc group-3 as referent, patients in CHA2DS2-VASc group-0 [0.18(0.14-0.23, p<.001)], group-1[0.33 (0.28-0.39, p<.001)], and group-2 [0.50 (0.43-0.58, p<.001)] were at significantly lower risk of developing stroke. Each increase of one point on the CHA2DS2-VASc scale was associated with a 51% [1.51(1.45-1.58, p<.001)] increase in incidence of stroke. Conclusion: CHA2DS2-VASc score predicts incidence of stroke in patients without history of A-Fib/ Flutter.