Modifiable factors associated with postoperative atrial fibrillation in older patients with hip fracture in an orthogeriatric care pathway: a nested case–control study

BACKGROUND: Few data are available regarding post-operative atrial fibrillation (POAF) in non-cardiothoracic surgery, particularly orthopedic surgery. Hence, given the frequent incidence of POAF after surgery and its marked impact, we need to identify modifiable factors associated with POAF after hip fracture surgery in older patients. METHODS: We conducted a nested case-control study in the unit for perioperative geriatric care of an academic hospital in Paris from July 1, 2009 to December 31, 2019, enrolling all consecutive patients aged ≥ 70 years with hip fracture surgery and no history of permanent AF before admission (retrospective analysis of prospectively collected data). Patients with and without POAF were matched 1:5 on 5 baseline characteristics (age, hypertension, diabetes, coronary artery disease, cardiac failure). RESULTS: Of the 757 patients included, 384 were matched, and 64 had POAF. The incidence of POAF was 8.5%. The mean age was 86 ± 6 years, 298 (78%) patients were female, and the median Charlson Comorbidity Index was 6 (interquartile range 4-8). The median time from surgery to the occurrence of POAF was 2 days (1-4). On multivariable conditional logistic regression analysis (matched cohort), the modifiable factors present at admission associated with POAF were time to surgery > 48 h (odds ratio [OR] = 1.66, 95% confidence interval [1.01-2.81]) and > 2 units of packed red blood cells (OR = 3.94, [1.50-10.03]). CONCLUSIONS: This study provides new information about POAF in older patients with hip fracture surgery, a surgical emergency whose complexity requires multidisciplinary care.