Sepsis, atrial fibrillation and mortality risk: an updated systematic review and meta-analysis of >3 million patients

Objectives: To evaluate the new-onset atrial fibrillation (NOAF) prevalence and the overall, in-hospital, post-discharge mortality, and ischemic stroke risk associated with NOAF in septic patients. Methods: Systematic review and meta-analysis of studies reporting the prevalence and risk of NOAF in patients with sepsis (PROSPERO CRD420261284949). MEDLINE and EMBASE were searched from inception to 31st December 2025. Within eligible studies, mortality and stroke risk were analyzed. Random-effects models were used to calculate pooled effects estimated with Odds Ratio (OR) and 95% confidence intervals (95%CI). Risk of bias was assessed by ROBINS-I tool. Results: 15 including 3,323,792 patients were analyzed. The NOAF prevalence was 13.27% (95%CI 8.16-19.4, p<0.001), from 6.74% in ordinary hospitalizations to 21.47% in intensive care units. Sepsis was associated with NOAF risk (OR 3.95, 95%CI 1.53-10.22, p<0.001). NOAF patients had higher all-cause mortality risk (OR 2.22, 95%CI 1.63-3.03, p<0.001), either in-hospital (OR 2.21, 95%CI 2.00-2.45, p<0.001), or post-discharge (OR 1.32, 95%CI 1.12-1.57, p<0.001), and ischemic stroke (OR 1.17, 95%CI 1.09-1.25, p<0.001). Mortality risk varied according to sepsis definition by ICD code (OR 2.13, 95%CI 1.29-3.52, p<0.001), Sepsis-2 (OR 4.52, 95%CI 2.24-9.09, p<0.001), Sepsis-3 (OR 1.64, 95%CI 1.21-2.22, p=0.002) and clinical criteria (OR 2.46, 95%CI 1.17-5.18, p=0.02). Conclusions: NOAF is a frequent cardiac complication of septic patients and is associated with increased mortality and stroke risk.