Atrial Fibrillation and Mortality in the Oldest Old after Surgery for Hip Fractures

Introduction: One-year mortality following hip fractures increases steeply with age, from 2% in the 60- to 69-year-old population up to 28% in the oldest old (older than 90 years). Of the various factors that contribute to hip fractures, atrial fibrillation (AF) is an independent risk factor at any age. Objective: The objective of this study was to assess the association of AF with mortality among the oldest old with hip fractures. Method: This is a retrospective cohort study of 701 persons above age 90 years who underwent orthopedic repair for a hip fracture during 2000-2018. Of them, 218 (31%) had AF at hospital admission. The primary outcome was survival following surgery. We compared patient characteristics and 30-day, 180-day, 1-year, and 3-year survival between patients with and without AF. Results: The adjusted odds ratio for 30-day postoperative mortality for those with AF versus without AF group was 1.03 (95% confidence interval [CI] 0.63-1.66). Survival estimates were higher among those without AF than with AF at 180 days postoperative: 0.85 (95% CI 0.82-0.89) versus 0.68 (95% CI 0.61-0.74), p < 0.001; at 1 year postoperative: 0.68 (95% CI 0.63-0.72) versus 0.48 (95% CI 0.42-0.55), p < 0.001; and at 3 years postoperative: 0.47 (95% CI 0.42-0.52) versus 0.28 (95% CI 0.27-0.34), p < 0.001. Conclusions: Among individuals aged >90 years, operated for hip fractures, mortality was similar for those with and without AF at 30 days postoperative. However, the survival curves diverged sharply after 180 days. Our findings suggest that AF is not an immediate surgical risk factor, but rather confers increased long-term risk in this population.