Risk of mortality in a cohort of patients newly diagnosed with chronic atrial fibrillation

OBJECTIVE: To estimate the mortality rate of patients newly diagnosed with chronic atrial fibrillation (AF) and compare it with the one in the general population. To evaluate the role of co-morbidity and other factors on the risk of dying among AF patients. METHODS: We used the General Practice Research Database in the UK to perform a retrospective cohort study. We followed a cohort of chronic AF patiens (N = 1,035) and an age and sex matched cohort of 5,000 subjects sampled from the general population. We used all deceased AF patients as cases (n = 234) and the remaining AF patients as controls to perform a nested case-control analysis. We estimated mortality risk associated with AF using Cox regression. We computed mortality relative risks using logistic regression among AF patients. RESULTS: During a mean follow-up of two years, 393 patients died in the general population cohort and 234 in the AF cohort. Adjusted relative risk of death in the cohort of AF was 2.5 (95%CI 2.1 – 3.0) compared to the general population. Among AF patients, mortality risk increased remarkably with advancing age. Smokers carried a relative risk of dying close to threefold. Ischaemic heart disease was the strongest clinical predictor of mortality with a RR of 3.0 (95% CI; 2.1–4.1). Current use of calcium channel blockers, warfarin and aspirin was associated with a decreased risk of mortality. CONCLUSIONS: Chronic AF is an important determinant of increased mortality. Major risk factors for mortality in the AF cohort were age, smoking and cardiovascular co-morbidity, in particular ischaemic heart disease.