Chronic atrial fibrillation - epidemiologic features in a population study

Purpose: Several epidemiologic studies, including the Framingham study and the Reykjavik study have shown that chronic atria] fibrillation (A.F.) is associated with increased morbidity and mortality. The Reykjavik study gives the opportunity to investigate this further, in both sexes and relate to a comprehensive survey of risk factors and clinical outcomes. Methods: The Reykjavik study is a prospective cardiovascular population study which started in 1967. It has been conducted in several stages in which the first five provided material for this investigation. Number of participants were 9139 males and 9773 females. A.F. was considered to be chronic if it was detected in a scheduled visit during the epidemiologic survey. Restults: Prevalence of A.F rose with increased age, being higher in males (4,7% at 70-75 years of age) than in females (0,8% at 70-75 years of age). Age, increased body height and left ventricularhypertrophy (L.V.H.) had significant association with A.F in males. In females age and L.V.H. were independent risk factors of A.F. By using Cox proportional hazard model the relative risk ratio (R.R.) among men with A.F. was 1,44 (95% C.I. 1,02-2,03) for total mortality and 2,66 (95% C.I. 1,08-6,51) for stroke mortality. Among women the corresponding R.R-figures were 2,65 (95% C.I. 1,46-4,80) for total mortality and 14,7 (95% C.I, 5,88-36,85) for stroke mortality. For neither sex was there an increased risk of cardiovascular mortality with A.F. Discussion: More men than women developed A.F. An interesting finding was the relationship between A.F. and body height in males. Elderly women with A.F were at an exeptionally high risk of dying from cerebrovascular insults. This premature morbidity spotlights the need for intensive prevention of A.F. and its complications.