Postoperative atrial fibrillation: Sex-specific characteristics and effect on survival

We sought to fill important gaps in the existing evidence regarding new-onset atrial fibrillation (AF) after coronary artery bypass graft surgery (CABG) by comparing the incidence, characteristics, and effect on long-term survival between men and women.

Nine thousand two hundred three consecutive patients without preoperative AF underwent isolated CABG from 2002 to 2010 at 3 US academic medical centers and 1 high-volume specialty cardiac hospital. Detailed data on CABG AF events detected via continuous in-hospital electrocardiogram/telemetry monitoring were supplemented with Society of Thoracic Surgeons data, and survival data, censored at October 31, 2011, using a copy of the Social Security Death Master File archived before state-owned data were removed (November 1, 2011).

Propensity-adjusted (Society of Thoracic Surgeons-recognized risk factors) incidence of post-CABG AF was 31.5% overall, 32.8% in men, and 27.4% in women. Over the 9-year study period, women had a significantly lower risk of post-CABG AF (absolute difference, -5.3% [95% confidence interval (CI), -10.5% to -0.6%]), and significantly shorter first (-2.9 hours; 95% CI, -5.8 to 0.0), and longest (-4.3 hours; 95% CI, -8.3 to -0.3) AF duration. Post-CABG AF was associated with significantly increased risk of long-term mortality (overall hazard ratio [HR], 1.56; 95% CI, 1.45-1.67; men HR, 1.57; 95% CI, 1.49-1.65; women HR, 1.54; 95% CI, 1.14-2.07).

In our study, women had lower adjusted risk of post-CABG AF and experienced shorter episodes. The adjusted risk of long-term mortality was 56% greater among patients who developed post-CABG AF compared with those who did not. The effect of post-CABG AF on long-term survival did not differ between the sexes.