Post-cardiac surgery atrial fibrillation and sex differences in clinical outcomes: a systematic review and meta-analysis

There is conflicting literature on sex differences and clinical outcomes in patients who develop atrial fibrillation (AF) post-cardiac surgery. Our aim was to compare clinical outcomes between females and males with post-cardiac surgery AF. A systematic search was conducted for studies published until 27 September 2024 in MEDLINE, Embase, and CENTRAL. Included studies compared mortality and stroke in females vs. males who developed AF after cardiac surgery. Outcomes of interest were mortality and stroke. Pooled prevalence was used to compare comorbidities. Raw event rates were used to calculate odds ratios (ORs), which were pooled with a fixed-effects model. 10 422 studies were identified and 5 studies met inclusion criteria. 14 970 patients who developed AF after cardiac surgery were included, of whom 3748 were females. The length of follow-up was up to 10 years. The weighted average age was 70.4 ± 2.9 years in females and 66.7 ± 2.4 years in males (P = 0.32). At baseline, females had a higher prevalence of hypertension, diabetes, dyslipidemia, stroke, and peripheral vascular disease. The odds of in-hospital mortality among females were higher compared to males (5.5 vs. 3.0%; OR 2.04, 95% CI 1.42–2.91, P < 0.001, I2 = 57%). There were no significant differences in post-discharge mortality (45.6 vs. 42.9%; OR 1.05, 95% CI 0.97–1.15, P = 0.23, I2 = 0%) or in-hospital stroke (2.5 vs. 1.9%; OR 1.30, 95% CI 0.79–2.13, P = 0.30, I2 = 57%) in females vs. males. In conclusion, females with post-cardiac surgery AF had a higher prevalence of comorbidities at baseline. The odds of in-hospital mortality were twice as high among females. There were no significant differences in post-discharge mortality or in-hospital stroke. Future studies are warranted to understand the mechanisms of increased in-hospital mortality in females and to develop effective monitoring strategies and interventions.