Summary
Whether atrial fibrillation (AF) is associated with an increased risk of venous thromboembolism
(VTE) remains controversial. From Longitudinal Health Insurance Database 2000 (LHID2000),
we identified 11,458 patients newly diagnosed with AF. The comparison group comprised
45,637 patients without AF. Both cohorts were followed up to measure the incidence
of deep-vein thrombosis (DVT) and pulmonary embolism (PE). Univariable and multivariable
competing-risks regression model and Kaplan-Meier analyses with the use of Aelon-Johansen
estimator were used to measure the differences of cumulative incidences of DVT and
PE, respectively. The overall incidence rates (per 1,000 person-years) of DVT and
PE between the AF group and non-AF groups were 2.69 vs 1.12 (crude hazard ratio [HR]
= 1.92; 95 % confidence interval [CI] = 1.54-2.39), 1.55 vs 0.46 (crude HR = 2.68;
95 % CI = 1.97-3.64), respectively. The baseline demographics indicated that the members
of the AF group demonstrated a significantly older age and higher proportions of comorbidities
than non-AF group. After adjusting for age, sex, and comorbidities, the risks of DVT
and PE remained significantly elevated in the AF group compared with the non-AF group
(adjusted HR = 1.74; 95 %CI = 1.36-2.24, adjusted HR = 2.18; 95 %CI = 1.51-3.15, respectively).
The Kaplan-Meier curve with the use of Aelon-Johansen estimator indicated that the
cumulative incidences of DVT and PE were both more significantly elevated in the AF
group than in the non-AF group after a long-term follow-up period (p<0.01). In conclusion,
the presence of AF is associated with increased risk of VTE after a long-term follow-up
period.
Keywords
Atrial fibrillation - venous thromboembolism - population-based cohort study - deep-vein
thrombosis - pulmonary embolism