New-Onset POAF After Craniotomy: Impact on Neurological Outcome, ICU Utilization, and Mortality

Background/Objectives: Atrial fibrillation is the most common sustained arrhythmia and frequently occurs in the perioperative setting. However, its clinical relevance in neurosurgical patients remains poorly defined despite increased vulnerability related to brain injury, inflammation, and perioperative stress. This study aimed to determine whether newly detected postoperative atrial fibrillation (POAF) identifies a higher-risk profile and is associated with postoperative complications, resource utilization, and short-term mortality compared with patients remaining in sinus rhythm (SR). Methods: We conducted a single-center retrospective cohort study (October 2020-April 2025). Among 2619 neurosurgical procedures, only patients with both pre- and in-hospital post-procedure ECGs and no pre-existing arrhythmia were included. POAF was defined as atrial fibrillation detected on any post-procedure ECG. Outcomes were compared using Welch's t-test, χ²/Fisher's exact tests, and odds ratios (OR) with 95% confidence intervals (CI). This study was not designed to estimate the incidence of POAF but rather to compare outcomes within a selected ECG-screened subgroup. Results: A total of 171 patients met the inclusion criteria: 79 (46.2%) developed POAF and 92 (53.8%) remained in SR. Patients with POAF were older and had a higher burden of cardiometabolic comorbidities and were more likely to undergo craniotomy/trepanation and emergency procedures. Compared with SR, POAF was associated with higher rates of postoperative complications, longer ICU and hospital stay, lower likelihood of discharge home, and higher short-term mortality. These findings reflect a selected ECG-screened cohort and should not be interpreted as the incidence of POAF in the overall neurosurgical population. Conclusions: Newly detected POAF is associated with a higher-risk postoperative profile in neurosurgical patients. It clusters with greater comorbidity burden, more invasive and urgent procedures, increased complications, prolonged hospitalization, reduced likelihood of discharge home, and higher short-term mortality. These findings support further evaluation of rhythm surveillance and perioperative management strategies in higher-risk neurosurgical populations.