EPIDEMIOLOGY OF ATRIAL-FIBRILLATION IN PATIENTS HOSPITALIZED IN A LARGE HOSPITAL

The prevalence of atrial fibrillation varies widely depending on the p opulation studied. To understand the incidence of atrial fibrillation and its significance in relation to other diseases, 3 years (1 989 thr ough 1991) of consecutive hospital discharges from the neurology and i nternal medicine services at Henry Ford Hospital were studied. Of the 26,964 patients who qualified for analysis, 1346 (5%) had atrial fibri llation as 1 of their 5 recorded discharge diagnoses. Comparing the gr oup without atrial fibrillation to those with atrial fibrillation, the re were 51% males in both groups (p = 0.88). African-Americans compris ed 33% of the patients with atrial fibrillation and 50% of the patient s without atrial fibrillation (p < 0.00 1). The average age of those w ith atrial fibrillation was 72 +/- 13 years, and 58 +/- 18 years for t hose without atrial fibrillation (p < 0.001). Length of hospital stay was 9.6 +/- 8.6 days with atrial fibrillation and 7.6 +/- 9.2 days for those without atrial fibrillation (p < 0.00 1). After adjusting for t he effects of age, significant positive associations were noted in tho se patients with atrial fibrillation whose co-existing condition was e ither stroke, heart failure, myocardial infarction, hyperthyroidism, o r mitral valve disease. There was also a significant negative relation ship between hypertension and atrial fibrillation. The most common of the 5 discharge diagnoses observed in patients with atrial fibrillatio n was congestive heart failure (40%), followed by hypertension (23%) a nd ischemic heart disease (21%). The existence of a comorbid disease i n patients with atrial fibrillation is important, as it can influence medical management and prognosis. The findings of this retrospective e pidemiologic assessment of atrial fibrillation warrant a larger prospe ctive evaluation.