Warfarin Underuse for Nonvalvular Atrial Fibrillation: How to Adjust Our Aims?

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice; its prevalence increases substantially with age, representing a growing epidemic with substantial effects on mortality and morbidity [1]. The more recent epidemiological data come from a large cross-sectional study in adults in California involving a population of 1.89 million [2]. The prevalence of AF was 0.95%, increasing from 0.1% among adults younger than 55 years to 9.0% in persons aged 80 years or older. The authors estimate that approximately 2.3 million adults in the USA currently have AF and project that this will increase to more than 5.6 million by the year 2050, with more than 50% of affected individuals aged 80 years or older. In Italy it is estimated that there are about 500,000 cases of AF at present, with 60,000 new cases per year.