Effect of cardiovascular drug classes on all-cause mortality among atrial fibrillation patients treated in primary care in Sweden: a cohort study.

BACKGROUND: Risk factors for stroke are well known in atrial fibrillation (AF) patients, while less is known on the effect of these factors on total mortality.
OBJECTIVE: Our aim was to study the impact of cardiovascular drug classes on mortality in AF patients treated in primary care.
METHODS: The study population was chosen based on patient data from 75 primary care centres in Sweden compiled in a database. Individuals diagnosed with AF who were older than 45 years were enrolled (n = 12,302, of whom 6,660 were men). Cox regression analysis with mortality (years to death) as outcome was conducted in the men and women separately, as well in the age categories <80 and ≥ 80 years, with cardiovascular drugs as independent factors, and age, cardiovascular diagnoses and educational level as covariates.
RESULTS: Lower mortality was shown for anticoagulant treatment among men, both younger (<80 years) [adjusted hazard ratio (HR) 0.43, 95 % confidence interval (CI) 0.31-0.61] and older (≥ 80 years) (adjusted HR 0.47, 95 % CI 0.32-0.69), and among younger women (adjusted HR 0.46, 95 % CI 0.29-0.74), and for antiplatelet treatment in older men (adjusted HR 0.51, 95 % CI 0.35-0.74). Treatment with thiazides was associated with lower mortality among younger men (adjusted HR 0.68, 95 % CI 0.48-0.96), older men (adjusted HR 0.67, 95 % CI 0.46-0.98) and older women (adjusted HR 0.70, 95 % CI 0.52-0.94). Statins were associated with lower mortality among younger patients, in both men (adjusted HR 0.47, 95 % CI 0.32-0.68) and women (adjusted HR 0.54, 95 % CI 0.35-0.82).
CONCLUSIONS: The differences in age and gender patterns need further exploration.