Abstract Background Atrial fibrillation (AF) is a common comorbidity in patients undergoing cardiac surgery and further increases the risk of incident heart failure (HF). However, only limited data exist on HF events following surgery in patients with AF. Methods The Left Atrial Appendage Occlusion Study (LAAOS) III was a randomized trial evaluating concomitant left atrial appendage occlusion in patients with AF undergoing cardiac surgery. In this secondary analysis, we aimed to identify independent predictors of the composite outcome of HF hospitalization or HF-related death following discharge, using a multivariable Cox model – incorporating sex, age (≥65 vs &amp;lt;65 years), systolic blood pressure (≤140 vs &amp;gt;140 mmHg), body mass index (BMI; &amp;lt;25 vs 25-29.9 vs ≥30 kg/m2), diabetes mellitus (DM), prior HF diagnosis, prior stroke, ischemic heart disease (IHD), heart valve surgery, AF history duration, rhythm on discharge electrocardiogram, and trial allocation. Supplementary analyses were undertaken to further assess the continuous variables using cubic spline regression. Results Of 4770 patients enrolled, in-hospital death occurred in 201 (4.2%) and complete discharge data were available for 4564 (95.7%). During a median follow up of 3.9 years, 533 (11.7%) of 4564 patients were hospitalized for HF. In total, 873 (19.1%) died after discharge, including 95 HF-related deaths. The composite outcome of HF hospitalization or HF-related death occurred at an annualized event rate of 3.31%/year [95% confidence interval: 3.04-3.60]. The independent risk factors included age (event rate of 3.64%/year vs 2.03%/year for ≥65 vs &amp;lt;65 years; hazard ratio (HR) 1.71 [1.32-2.21]), DM (4.71%/year vs 2.71%/year for with vs without DM; HR 1.59 [1.34-1.90]), prior HF diagnosis (4.27%/year vs 2.17%/year for with vs without HF; HR 2.00 [1.66-2.41]), IHD (3.63%/year vs 2.85%/year for with vs without IHD; HR 1.26 [1.03-1.54]), AF history duration (3.81%/year vs 2.89%/year for &amp;gt;2 vs &amp;lt;0.5 years; HR 1.23 [1.01-1.50]), and AF rhythm at discharge (3.87%/year vs 2.68%/year for AF vs non-AF rhythm; HR 1.31 [1.09-1.58]). The supplementary spline analyses further revealed a positive correlation between BMI and the risk of the composite outcome (p-value 0.042). Conclusions In patients with AF undergoing cardiac surgery, post-discharge HF hospitalization and HF-related death occurred at a rate of 3.31% per year. Our study identified several significant risk factors including advanced age, higher BMI, DM, prior HF diagnosis, IHD, AF history &amp;gt;2 years, and AF rhythm at discharge.The associations of HF with age and BMI

Incidence and predictors of heart failure events following cardiac surgery in patients with atrial fibrillation - insights from the LAAOS-III trial