Recent studies have demonstrated the limitations of the CHA2DS2-VASc score [congestive heart failure, hypertension, age (>65 years =1 point; >75 years =2 points), diabetes, and previous stroke/ transient ischemic attack (2 points), vascular disease] which lacks many of less common risk factors for stroke. Moreover, only two risk factors, gender and age, are assigned with different points according to the stratification in the CHA2DS2-VASc score. Thus, this meta-analysis was aimed to optimize the stratification of risk factors in and beyond the CHA2DS2-VASc score for patients in mainland China. PubMed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and Chinese Science and Technology Journal Database (VIP) were searched from their inception to January 2020 for articles assessing risk factors of nonvalvular atrial fibrillation (NVAF) with ischemic stroke in mainland China. Odd risks (ORs) with 95% confidence intervals (CIs) were applied for dichotomous variable, and the weighed mean differences (WMDs) with standard deviations (SDs) were used for continuous variables. The meta-analysis included 20 eligible studies involving 14,675 patients. Compared with the non-stroke group [systolic blood pressure (SBP): 132.99 mmHg, 95% CI: 131.86-134.12; diastolic blood pressure (DBP): 80.08 mmHg, 95% CI: 78.63-81.53], the ischemic stroke group (SBP:144.07 mmHg, 95% CI: 140.74- 147.40; DBP: 84.41 mmHg, 95% CI: 82.39-86.43) showed increased levels of SBP (WMD 10.98 mmHg, 95% CI: 7.80-14.17, P<0.00001) and DBP (WMD 4.46 mmHg, 95% CI: 2.57-6.35, P<0.00001). In addition, the ischemic stroke group demonstrated significantly lower levels of left ventricular ejection fractions (LVEFs) (WMD 3.05% 95% CI: -5.96 to -0.14, P=0.04), and significantly higher levels of total cholesterol (TC) (WMD 0.32 mmol/L, 95% CI: 0.04-0.61, P=0.02) and low density lipoprotein cholesterol (LDL-C) (WMD 0.14 mmol/L, 95% CI: 0.02-0.26, P=0.02), as compared with the non-stroke group. The optimized stratification and the addition of risk factors in and beyond the CHA2DS2-VASc score may improve the predictive performance, thus helping to differentiate patients with the real thromboembolic risk.
Keywords: Nonvalvular atrial fibrillation; heart failure; ischemic stroke; mainland China; optimized stratification.