Risk factors and incidence of stroke and MACE in Chinese atrial fibrillation patients presenting to emergency departments: a national wide database analysis.

Background: Contemporary clinical risk stratification schemata for predicting stroke and thromboembolism in patients with atrial fibrillation (AF) are largely derived from western cohorts. The purpose of the present study is to assess the potential risk factors for stroke and major adverse cardiac events (MACE) in a large population of Chinese AF patients presenting to emergency department.

Methods: The Chinese AF registry is a multicenter, prospective, observational study with 1 year follow up. Patients who presented to an emergency department with atrial fibrillation or atrial flutter were recruited from November 2008 to October 2011. The MACE included all cause mortality, stroke, non-central nervous system systemic embolism and major bleed.

Results: A total of 2016 AF patients (1104 women) were included in the final analysis. Multivariate Cox regression analysis showed that the risk factors for stroke were female gender (1.419 (1.003-2.008), p=0.048), age ≥ 75 (2.576 (1.111-4.268), p<0.001), previous stroke/TIA (2.039 (1.415-2.939), p<0.001), LVSD (1.700 (1.015-2.848), p=0.044) and previous major bleeding (2.481 (1.141-5.397), p=0.022). For MACE, age ≥ 75 (3.042 (2.274-4.071), p<0.001), heart failure (1.371 (1.088-1.728), p=0.008), previous stroke/TIA (1.560 (1.244-1.957), p<0.001), LVSD (1.424 (1.089-1.862), p=0.010) and COPD (1.393 (1.080-1.798), p=0.011) were independent risk factors. History of hypertension and diabetes was not associated with the events, neither stroke nor MACE. For non-anticoagulation patients, the c-statistic for predicting stroke was 0.685 (0.637-0.732) and for MACE was 0.717 (0.687-0.746), respectively.

Conclusions: We demonstrated that, except for the traditional risk factors, clinicians should pay more attention to patients with prior major bleeding or COPD in Chinese AF patients presenting to emergency department.