Little is known about temporal trends in atrial fibrillation (AF) incidence, prevalence, and outcomes. Using the Framingham Heart Study, Schnabel and colleagues assessed AF incidence, prevalence, and outcomes over 50 years (202,417 person-years). Researchers drew on a cohort of 9,511 participants enrolled between 1958 and 2007 in which 1,544 incident AF cases (47% women) were identified. Over the study period, age-adjusted incidence increased threefold (3.7 to 13.4 new cases per 1000 person-years in men and from 2.5 to 8.6 new cases per 1000 person-years in women) and age-adjusted prevalence increased fourfold (20.4 to 96.2 cases per 1000 person-years in men and from 13.7 to 49.4 cases per 1000 person-years in women). To mitigate lead-time bias that could result from improved methods to detect AF over time, researchers also evaluated temporal trends by AF detected solely through routine ECG screening of the study cohort. While age-adjusted prevalence increased over the study period, age-adjusted incidence did not significantly change over time in this sensitivity analysis. Outcomes improved over time, with adjusted hazards models showing a 74% decrease in stroke (HR 3.77, 95% CI 1.98–7.20 in 1958–1967 compared with 1998–2007; ptrend=0.0001) and a 25% decrease in mortality (HR 1.34, 95% CI 0.97–1.86 in 1958–1967 compared with 1998–2007; ptrend=0.003).
Conclusions: Rising temporal AF trends are, in part, due to enhanced detection methods over time. Improved outcomes of AF likely reflect advances in the delivery and quality of cardiovascular care. Future efforts to reduce AF burden must integrate improved screening measures with enhanced education and prevention.
- Schnabel RB, Yin X, Gona P, Larson MG, Beiser AS, McManus DD, Newton-Cheh C, Lubitz SA, Magnani JW, Ellinor PT, Seshadri S, Wolf PA, Vasan RS, Benjamin EJ, Levy D. 50 year trends in atrial fibrillation prevalence, incidence, risk factors, and mortality in the framingham heart study: A cohort study. Lancet. 2015 May 7. pii: S0140-6736(14)61774-8. [E-pub ahead of print]