Temporal Trends in Multimorbidity Patterns in Patients With Atrial Fibrillation-A Nationwide Cohort Study.

BACKGROUND: The prevalence of both atrial fibrillation (AF) and multimorbidity is increasing with population aging. However, reliable and comprehensive data on temporal trends in multimorbidity among patients with AF are lacking. METHODS: The nationwide Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) cohort study includes all patients with incident AF between 2009 and 2018. Data on comorbidities were obtained from national healthcare, reimbursement and prescription registers using a fixed 5-year look-back period. A previously established comorbidity categorisation was applied to characterise multimorbidity burden. Temporal trends in the prevalence of common comorbidities and in the number of distinct diagnosis groups at the time of new-onset AF were calculated. RESULTS: Overall, 85% of 196,536 individuals with new onset AF had diagnoses from ≥ 2 comorbidity groups and 28% from ≥ 6 comorbidity groups. Mean number of different groups increased from 3.9 to 4.2 between 2009 and 2018. Although adjustment for age attenuated the association, the increase in multimorbidity over time remained significant after adjustment for age and sex. Multimorbidity was more common in women than in men (4.2 vs. 3.9) and increased with age. Hypertensive diseases, obesity and other metabolic diseases, diabetes and other cardiovascular diseases were most prevalent. The prevalence of ischaemic heart disease and other diseases of the heart and pulmonary circulation declined during the study period. CONCLUSIONS: Multimorbidity is highly prevalent and increasing among patients with AF, highlighting the importance of a holistic management approach.