• atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide and the estimated global age adjusted prevalence was 0.5% in 2010, representing nearly 33.5 million individuals.1 The prevalence is likely underestimated as a large proportion of asymptomatic individuals and those having transient symptoms remain undiagnosed. It is recognised as a global public health problem due to its significant burden of morbidity and mortality resulting from embolic stroke, congestive heart failure and acute coronary syndrome. AF may affect functional status and impairs the quality of life. The incremental cost related to AF in the USA is estimated at US$6–26 billion per year.2 Thus, AF already has tremendous implications on the economy and public health.

Numerous studies have reported AF as a growing epidemic with an expected doubling of its prevalence by 2030.3 However, most of the studies were conducted in the western world and epidemiological studies of AF in the Asian continent are scarce. Furthermore, the healthcare implications of the rapidly changing population dynamics in this region are poorly understood. As the prevalence is expected to rise, it is important to have an updated epidemiology of AF in order to allocate human and economic resources for appropriate healthcare planning. Two thirds of the AF-related healthcare expenses are from direct and indirect inpatient cost. Tremendous regional variation in hospitalisation for AF has been reported. Hence, the analysis of utilisation of hospitalisation is key to allocate resources accordingly.

In this context, Kim et al used the National Health Insurance Service (NHIS) database of Korea to describe the temporal trends of hospitalisation, costs, treatment patterns and outcomes of AF in Korea.4 Kim and colleagues found a substantial increase in the hospitalisation rates of AF from 767 per million in 2006 to 3986 per million Koreans in 2015. More than 80% of the hospitalised patients are >70 years of age. Octogenarians (>80 years) were the largest age group to be hospitalised and also had the highest exponential increase in hospitalisation from 8185 per million Koreans in 2006 to 48 388 per million Koreans in 2015. The mean age of the study population increased from 69.5 in 2006 to 73.3 in 2015 which reflect the changing population characteristics in this region and also explain the growing rates of AF. The rising AF-related hospitalisation has been reported in multiple studies across the world. We described an increasing trend of AF-related hospitalisations over the last decade and its enormous financial burden on the US economy utilising a national representative sample.3 In Europe, studies showed that the prevalence of AF more than doubled compared with a decade earlier.5 Similarly, Wong et al described a 200% increase in AF-related hospitalisations over a 15-year study period in Australia.6 Although increasing age has often been held responsible, alternative explanations include the congruent increase in the burden of comorbid conditions like hypertension, diabetes mellitus, heart failure and chronic obstructive pulmonary disease and more widespread use of improved diagnostics for AF.

The growing epidemic of AF creates a significant burden on healthcare systems and economies throughout the world. About 50%–70% of the financial burden of AF is attributable to hospitalisation costs. In the USA, there was a 24% increase in the mean cost of AF hospitalisation with a corresponding increase in the economic burden by nearly $1.31 billion during the last decade.3 Similarly, in the study by Kim et al, despite a static mean cost of hospitalisation, the overall annual national cost increased from € 68.4 million in 2006 to € 388.4 million in 2015. The present analysis does not include utilisation of outpatient resources, so the prevalence and cost are underestimated. Moreover, the mean length of stay was significantly longer in Korea than other regions of the world. The authors attribute this phenomenon to cheaper hospitalisation costs and generous reimbursement policies in Korea. So, efforts to reform healthcare reimbursements and aggressive measures to shorten the length of stay should be actively undertaken.

The changing treatment patterns of AF captured over a 10-year period in this study merit some discussion. There was a modest 36% increase in the utilisation of oral anticoagulants (OACs) like warfarin and novel OACs (NOACs) while the use of aspirin decreased. Yet, there was a quadrupling of hospitalisations due to major bleeding and a doubling of hospitalisations due to ischaemic stroke. These results presented by Kim and colleagues are similar to a recent study by Lee et al who studied the temporal trends in the use of antithrombotic therapy and OACs using the same database, NHIS.7 These changing prescription patterns reflect increasing adherence of the Korean physicians to the treatment guidelines in real world clinical practice. However, recently Huisman et al studied the global patterns of OAC use utilising the GLOBAL-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) registry.8 The investigators found that NOACs were more frequently prescribed over warfarin in the North America and Europe, while the use of NOAC was less common in the Asia subcontinent. Although there is still an underutilisation of NOACs in the Asian continent compared with other regions of the world, these treatment patterns might be expected to change over time, especially with recent studies showing that NOACs have more beneficial effects in the Asians compared with other races. As a reflection of this, Kim and colleagues found a dramatic increase in the prescription of NOACs between 2014 and 2015. The implications of increased NOAC use on both hospitalisation and ischaemic stroke require further study.

As the prevalence of AF is expected to increase even more in the next couple of decades, cost-effective strategies to limit its burden should be actively explored. A multipronged approach is necessary that focuses on primary prevention, optimal resource utilisation and improved utilisation of proven therapeutic approaches in patients with AF. Adoption of population-based interventions and preventive strategies like aggressive cardiometabolic risk factor modification could have a major impact on the incidence of AF. While not tested as a primary prevention strategy, several studies have highlighted the role of risk factor modification on the burden of AF. The need for hospitalisation for patients with AF should also be carefully considered. The regional variation in hospitalisation rates suggest that there may be overutilisation of hospitalisation. AF is a chronic disease and requires long-term outpatient management. The usage of hospitalisation for patients with AF without other acute issues requiring hospitalisation is unclear. As much of the disability in patients with AF is caused by stroke, what remains more concerning is the fact that one in five patients do not receive adequate stroke prophylaxis.8 So, a multidisciplinary team approach aimed at providing better anticoagulation services and active implementation of educational programmes to enhance patient understanding of the disease process are some of the other measures that can be adopted. Furthermore, widespread screening measures to diagnose asymptomatic individuals have also been shown to be cost effective.

In conclusion, Kim and colleagues highlighted the growing epidemic of AF causing significant increase in hospital use in South Korea. This study adds to the existing literature on the rising rates of AF that are well described on a national scale in developed countries of the west. Taken together, the rising global trends of hospitalisations for AF are causing considerable burden on healthcare systems throughout the world. This underscores the urgent need for healthcare systems around the world to develop and implement programmes for preventing AF and new paradigms to optimise identification and treatment of patients with AF.