Prevalence and Predisposing Factors of Atrial Fibrillation in a Multi-Ethnic Society: The Impact of Racial Differences in Bahrain

Aim: Evaluation of the prevalence and predisposing factors of AF in patients who were admitted to acute medical emergencies (ER) in Bahrain over the period of one year.

Methods: Two hundred and fifty three patients with onset of AF were studied. The mean difference of biochemical data and clinical characteristics between Middle Eastern (ME) and sub continental (SC) patients was evaluated. The odds ratio of different predisposing factors for the development of clinical events in AF patients was assessed using multiple logistic regression analysis.

Results: Out of 7,450 patients that were admitted to ER over one year, 253 had AF based on twelve leads Electrocardiogram (ECG), with prevalence of 3.4%. In the whole study, the mean age was 59.45 ± 18.27 years, with 164 (65%) male. There were 150 ME patients (59%), and 107 (41%) SC, 55 (22%) were Indian (IND) and 48 (19%) were South Asian (SA). In the whole study clinical presentation was of 48% for palpitation, pulmonary edema was of 14%, angina pectoris on rest of 12%, 10% had embolic phenomena, 6% had dizziness, and 7% were asymptomatic. The odds ratio of different variables for occurrence of clinical events in the study was positive of 2.2 for history of hypertension, 1.8 for sickle cell disease, 1.2 for high body mass index (BMI) .30, 1.1 for mitral valve disease. The ME patients, compared with SC, were older, had significantly higher body mass index, higher history of rheumatic valve disease, sickle cell disease with high level of uric acid and lower hemoglobin. The history of hypertension, DM and smoking was higher among the SC patients. The rate of thyroid disease was equal in both groups.

Conclusion: The prevalence of atrial fibrillation was 3.4% with male predominance of 65%. Patients of sub continental origin were younger with a significantly high history of hypertension and ischemic heart disease. The patients of Middle Eastern origin had significantly high rate of rheumatic heart disease, and sickle cell disease. The history of hypertension was the most important independent clinical predictor of adverse events in patients presented with AF.