Abstract 3890: Guideline Adherent Antithrombotic Treatment is Associated with Improved Cardiovascular Outcome Compared to Undertreatment in Real-Life Atrial Fibrillation Patients at High Risk for Stroke
Background Atrial fibrillation (AF) management guidelines give recommendations on antithrombotic treatment (ATT) for prevention of thromboembolism (TE), specifically stroke.
Hypothesis Real-life guideline adherence for ATT in AF is associated with improved cardiovascular outcome compared to undertreatment, whereas overtreatment leads to avoidable bleedings.
Methods The Euro Heart Survey on AF (2003–2004) enrolled 3634 AF pts at high-risk for stroke, and for whom 1 year follow-up was known. Guideline adherence was assessed according to the ACC/AHA/ESC guidelines. Overtreatment was defined as oral anticoagulation (OAC) in patients with at least 1 bleeding risk factor (BRF) or inappropriate use of a combination of OAC and an antiplatelet drug. Undertreatment was no OAC in pts without a BRF, and no antiplatelet agent in pts with a BRF. The independent association between ATT guideline adherence and incidence of major adverse events during 1 year follow-up was evaluated with multivariable logistic regression. Odds ratio (OR) with 95% confidence interval is reported.
Results In only 60% the guidelines were followed, and much more pts were undertreated (29%) than overtreated (11%). Univariable comparison of respectively undertreatment, guideline adherence and overtreatment, shows that incidence of cardiovascular death (3.0 vs 2.0 vs 5.7%; p<0.001), any TE (4.5 vs 2.6 vs 4.7%; p=0.009) and the combined endpoint was lowest in guideline adherence, stroke rate was comparable (2.2 vs 1.7 vs 1.3%; p=0.478) and major bleeding rate was highest in overtreatment (1.5 vs 1.7 vs 4.5%; p=0.001). Compared to guideline adherence, undertreatment was independently associated with occurrence of any TE (OR=1.97 (1.29–3.01); p=0.004) and the combined endpoint of cardiovascular death, any TE and major bleeding (OR=1.54 (1.14–2.10); p=0.024), but not with stroke exclusively (OR=1.42 (0.86–2.42; p=0.170). Overtreatment was not significantly associated with occurrence of major bleeding compared to guideline adherence (OR=1.52 (0.76–3.02); p=0.405).
Conclusions In this real-life population, antithrombotic undertreatment was associated with worse cardiovascular outcome, whereas overtreatment was not associated with occurrence of major bleeding.