Prevalence of and Risk Factors for Paroxysmal Atrial Fibrillation in Patients with Cardiovascular Disease but without diagnosed Atrial Fibrillation

Background: Atrial fibrillation (AF) is the most prevalent arrhythmia in the clinical practice, and a range of cardiovascular disease (CVD) is associated with the increased risk of AF.While many epidemiological studies identified risk factors for AF in general population, there have been few studies investigating the prevalence of and risk factors for paroxysmal AF (Paf) in patients with CVD.In this study, we examined the prevalence of Paf and attempted to define the risk factors for Paf in patients with CVD but no known history of AF.Study Design and setting: We selected 342 patients who had prior CVD, or were at risk for CVD, but had not been diagnosed with AF.All patients were followed up with specified tests (e.g., blood tests and urinalysis) at our outpatient clinic.To detect Paf in these patients, a 24-hour Holter electrocardiography (ECG) was performed.Results: Paf was detected in 25 patients (7.2 %) in 342 enrolled patients (mean age, 67.0 years; men, 42.2%).Comparison of clinical features showed that patients with Paf were older (p=0.02), had higher serum brain natriuretic peptide (p=0.04)than those without Paf.More patients with Paf had a history of heart failure (HF) (56.0 % vs.15.7%; odds ratio [OR], 6.81; 95% confidential interval [CI] 2.93 to 15.9; p<0.0001) and proteinuria (32.0% vs. 15.1%;OR 2.64;95%CI 1.08 to 6.45; p=0.03) as well as with advancing age (OR 1.03; 95%CI 1.00 to 1.06; p=0.03).Multivariate logistic regression analysis revealed that HF was significantly associated with Paf independently of other comorbidities (OR 5.40; 95%CI 2.07 to 14.1; p=0.0006).Conclusion: Our study using 24hour Holter ECG readily identified Paf in the patients with CVD but without diagnosed AF.HF was most strongly associated with Paf independently of other risk factors established by prior population-based studies.A history of HF should be considered as a leading risk factor for Paf in clinical practice.