Body mass index may alter cardiovascular outcomes in patients with newly-diagnosed atrial fibrillation and previous stroke: an interaction analysis using longitudinal data from the GLORIA-AF registry

Abstract Background Patients with new onset atrial fibrillation (AF) and previous stroke (PS) are at higher risk of cardiovascular (CV) outcomes. An obesity paradox, where overweight or obese patients have better outcomes, has been seen. Whether body mass index (BMI) modify the risks of cardiovascular (CV) events and mortality in AF patients with PS remains uncertain. Purpose To ascertain whether BMI of AF patients with PS events alters risks of CV outcomes. Methods A cohort from phase III of the prospective GLORIA-AF (Global Registry on Long-Term Oral Anti-thrombotic Treatment in Patients With Atrial Fibrillation) was included. Risks of Major Adverse Cardiovascular Events (MACE), CV death, and all-cause mortality were analysed using COX proportional hazard regression with interaction terms added between PS and the BMI characteristics. Results Data from 17482 patients [median age: 71.0 (IQR: 64.0–78.0) years; 45.3% female] with newly-diagnosed AF were analysed and included in risk models. At baseline, 1840 (10.5%) patients with AF had PS in which 1694 (9.7%) and 170 (0.97%) patients had one (1 PS) and ≥2 (2 PS) respectively. After a median follow-up of 3.0 (IQR: 2.9–3.1) years, 1111 MACE, 562 CV deaths, and 1266 all-cause deaths were recorded. In a multivariate COX regression model, interaction between BMI and PS was significant in predicting risk of CV death (Pint =0.019). BMI was also associated with increased risk of CV death among AF patients with ≥1 PS. The interaction between PS and BMI was borderline significant in predicting MACE (Pint=0.063) and all-cause death (Pint=0.057). Figure 1 showed the different risks associated with different BMI statuses. Conclusion The risks of adverse CV outcomes were higher in AF patients with higher BMI and previous stroke. An obesity paradox was not evident in AF patients with previous stroke.Figure 1