Association of female sex with adverse clinical events in patients with new-onset post-operative atrial fibrillation: insights from the VISION cardiac surgery cohort
W F McIntyre, P J Devereaux, R P Whitlock, J D Spence, A Lamy, D Paparella, K Brady, E Methangkool, C Y Wang, C A Polanczyk, S Fremes, V V Lomivorotov, R Zhao, J S Billing, E P Belley-CoteAbstract
Background
New-onset post-operative atrial fibrillation (POAF) affects approximately 1 in 3 patients after cardiac surgery and is associated with adverse outcomes. Whether females who develop POAF are higher risk for adverse outcomes compared to males is unclear.
Methods
VISION Cardiac Surgery was an international, prospective cohort of a representative sample of patients who underwent cardiac surgery at 22 centres, in 11 countries. Participants were enrolled pre-operatively and followed for 1 year. In patients without a pre-operative history of AF, we assessed the association of new-onset POAF, as compared to no POAF, with clinical events occurring between 30 days post-operatively and 1 year of follow up, stratifying for female and male sex. For each outcome, we created a Cox proportional hazards model adjusted for CHA2DS2-VA score, smoking, hemodialysis, prior cardiac surgery, surgery type, and antithrombotic use at hospital discharge (oral anticoagulation alone, oral anticoagulation plus antiplatelet agent, antiplatelet agent alone, or none).
Results
Among 12,234 eligible participants, 3,887 (31.8%) had new-onset POAF; 32.2% of females (1042/3232) and 31.6% of males (2845/9002).
Compared with those without POAF, females with POAF had a significantly higher risk of the primary outcome, a composite of vascular death and stroke: (3.4% vs 1.2%, adjusted hazard ratio [aHR] 2.28 (1.36-3.83), while the same was not true for males (1.9% vs 1.6%, aHR 0.99 (0.70-1.40)), p-interaction = 0.007. The excess risk in females was driven by stroke (1.2% vs 0.3%, aHR 3.76 (1.42-9.98), and no such association was observed in males (0.7% versus 0.7%, aHR 0.73 (0.41-1.31), p-interaction = 0.004. No significant sex differences were observed in adjusted hazards for vascular death, all-cause death, congestive heart failure, major bleeding, re-hospitalization for vascular cause, or AF occurring > 30 days post-operatively.
Conclusions
Females who experience POAF following cardiac surgery may carry an elevated risk of stroke in the year following surgery, while males do not.