Trends in atrial fibrillation predict major incidence increase towards 2060
Temporal Trends in Incidence, Prevalence, and Mortality of Atrial Fibrillation in Primary Care
Almost every published study has demonstrated an increased incidence and prevalence of atrial fibrillation (AF), which is suspected to rise substantially in the next decades [1-7]. However, the majority of these observations included AF patients as part of cohort studies or AF registries, whereas data reflecting unselected clinical populations is lacking.
The aim of current study was to investigate temporal trends in AF incidence, comorbidities and mortality in a primary care population (UK Clinical Practice Research Datalink, CPRD GOLD, n=57 818, representing ~8% of the UK population), to get insight into the future AF population profile in the United Kingdom. The study population comprised adults with first incidence AF from 1998-2010.
- Study population comprised 48.3% women, 51.7% men with a mean age of 71.5 years.
- Over the years, there was clear evidence an ageing AF population; the proportion >85 years increased from 15.5% in 1998-2001 to 16.1% in 2002-2006 and 19.0% in 2007-2010.
- Over time, the proportion of AF patients with previous stroke/TIA and vascular disease at the time of diagnosis was stable (11-15%), but clear increases were observed in the prevalence of hypertension (46-61%) and diabetes mellitus (9-14%). In contrast, incidence of ischemic heart disease at time of AF diagnosis decreased (44-37%).
- The CHA2DS2VASc score remained similar across all time periods (mean 3.2).
- The AF incidence increased with age from 0.13 (95% CI 0.13-0.13) per 1000 person-years in those aged <55 years, to 1.16 (95% CI 1.13-1.19) for 55-64 years, to 3.24 (95% CI 3.19-3.30) for 65-74 years, to 6.42 (95% CI 6.33-6.52) for 75-84 years, to 7.65 (95% CI 7.48-7.81) per 1000 person-years in those aged >85 years.
- More men experienced AF compared to women (1.33 vs 1.18 per 1000 person-years, respectively).
- Age-adjusted incidences over time were 1.11 in 1998-2001 (95% CI 1.09-1.13), 1.33 in 2002-2006 (95% CI 1.31-1.34) and 1.33 in 2007-2010 (95% CI 1.31-1.35). While this was quite stable for younger patients, incidence increased over time for older patients >75 years (see slide).
- 1-year mortality rate was 8.8% in women was 8.8% (95% CI 8.4-9.1) and in men was 10.6% (95% CI 10.2-11.0). In patients aged 55-74 there was a reduction in mortality over time (IRR per calendar year 0.97, 95% CI 0.95-0.99, P<0.001), while in patients >75 years mortality was similar over time (IRR 1.00, 95% CI 0.99-1.01, P=0.84).
- Based in these data, the prevalence of AF in 2010 is estimated at 14.5 per 1000 person-years and 83.6 per 1000 >75 years. Assuming a constant incidence rate from 2010 onward, the expected number will be 15.5 in 2020, 20.5 in 2040 and 25.4 in 2060, and rates are expected to rise faster in men than in women.
The incidence of AF between 1998 and 2010 plateaued overall, but a continued increase was observed for patients >75 years and it was more common in men than in women. This number is expected to significantly increase towards 2060. Moreover, mortality in these older patients did not decrease as with younger patients, despite improvements in management. The increase will reflect a major public health burden in 2060 and will be accompanied by temporal changes in AF-related comorbidities. This suggests therefore the need for comprehensive implementation of AF prevention and management strategies.