Incidence and outcome of atrial fibrillation: diversity throughout Europe

The incidence and prevalence of atrial fibrillation (AF) have been increasing over time and are expected to rise further due to extended life expectancy, accumulation of lifestyle-related risk factors such as obesity and diabetes mellitus, and a better survival after myocardial infarction and heart failure (HF). In addition, a better awareness of AF and improved and intensified technology for undiagnosed AF contribute to an increase in AF burden. In addition to the incidence and prevalence of AF, the AF-associated mortality rate is increasing. Mortality is the highest early after diagnosis of AF, being 5–6% in the first year after the initial presentation due to as yet undiagnosed underlying cardiovascular diseases and therefore far less well treated AF. Many associated conditions contribute to incident AF as well as to AF-related mortality including increasing age, hypertension, diabetes mellitus, HF, coronary artery disease, obesity, and chronic kidney disease. The incidence of AF is higher in men than in women. The moment of onset of AF as well as the associated comorbidities differ between men and women. Women are older, have a higher prevalence of hypertension, valvular heart disease, and HF with a preserved ejection fraction (HFpEF), and less often have coronary artery disease. Most data on the incidence of AF and AFrelated mortality come from higher income Western countries. Recent data, however, show that there exists a large global variation in age of onset, risk factors, and concomitant diseases associated with AF and treatment of AF among different regions. This may all contribute to European regional differences in incidence of AF and AFassociated mortality. In this issue of the European Heart Journal, Al-Khayatt et al. provide us with timely information about the incidence of AF and AFassociated mortality during the last 28 years in men and women from 20 countries in Europe. Data on trends in incidence and mortality, and the incidence and mortality in 2017, are presented. A comparison is made between Western and Eastern European countries, higher vs. lower gross domestic product (GDP) countries, and men vs. women. Incidence and AF-associated mortality were determined from the Global Burden of Disease (GBD) Study database, a comprehensive global programme that assesses mortality and morbidity from major diseases. These were subsequently collated by the Institute of Health Metrics and Evaluation. The countries were chosen to provide a representative sample across Europe, but only if they had a population >4 million and met the data reliability criteria. Trends were analysed using Joinpoint regression analysis; missing data were imputed using the last observation carried forward method. Key findings include, first, that the rates of change of AF incidence are heterogeneous throughout Europe, with some nations with substantially lower rates than others. Some Western European countries experienced peaks in incidence in the middle of the study period. In contrast, most lower GDP countries showed a gradual decline in AF incidence over the years. AF incidence was consistently higher in the Western European countries as compared with Eastern European countries, and in men as compared with women. Interestingly, incidence rates were not increasing as much as might have been expected. Second, AF-related mortality is increasing more rapidly than AF incidence, especially in the higher GDP countries. As a result, AFrelated mortality is significantly greater in higher GDP countries. Remarkably, mortality was not different between men and women, in