Pre-existing Atrial Fibrillation and Long-term Outcomes Following Total Knee Arthroplasty

Abstract A significant population of patients undergoing total knee arthroplasty (TKA) concomitantly have atrial fibrillation (AF). Previous studies have examined acute postoperative complications; however, the long-term impact of pre-existing AF on surgical outcomes after TKA remains underexplored. This study aimed to evaluate 2-, 5-, and 10-year risk and indications for revision among patients with AF undergoing TKA. The TriNetX database was utilized for this retrospective cohort study. The primary outcome was 2-, 5-, and 10-year risk of revision following primary TKA among patients with and without pre-existing AF. The AF and control cohorts were 1:1 propensity matched by age, sex, race, clinical comorbidities, and anticoagulant and aspirin use. Covariate balance after matching was assessed using standardized mean differences (SMDs). Cox proportional hazards models and Kaplan-Meier survival estimates were used to evaluate all-cause revision and specific complications. Results were reported as hazard ratios (HRs) with 95% confidence intervals (CIs), survival probabilities, and p-values. A p-value of < 0.05 was considered statistically significant. Patients with pre-existing AF (n = 24,671) had a significantly higher risk of all-cause revision at 2 years (HR 1.27, 95% CI: 1.13–1.43, p < 0.0001), 5 years (HR 1.23, 95% CI: 1.11–1.37, p < 0.0001), and 10 years (HR 1.23, 95% CI: 1.12–1.35, p < 0.0001) post-TKA compared to matched controls (n = 24,671). The AF cohort demonstrated increased risk of periprosthetic joint infection (PJI) (HR 1.33, 95% CI: 1.22–1.44, p < 0.0001) while showing decreased incidence of arthrofibrosis (HR 0.85, 95% CI: 0.80–0.91, p < 0.0001). No significant difference in periprosthetic fracture, mechanical loosening, osteolysis, or articular wear was observed. Pre-existing AF is associated with increased long-term risk of revision following TKA up to 10 years postoperatively compared to matched controls, even after matching for comorbidity burden and anticoagulant use. These findings should be interpreted cautiously in the context of modest effect sizes and limitations inherent within the TriNetX database. Future studies should examine whether perioperative anticoagulation management strategies influence long-term postoperative complications in patients with AF undergoing TKA.