RESUMO
Background: Studies analyze the degree to which gender-based differences are affected by age and comorbidities show mixed results. Methods: Using a retrospective cohort study, we analyzed 327 consecutive patients who presented to the emergency department (ED) due to Atrial Fibrillation (AF) from 2014 to 2017 with follow-up at one year. Results: Females with AF were older (p < 0.001), with higher Body Mass Indexes (BMI) (p < 0.001), and a higher rate of hypertension (p < 0.001), hyperlipidemia (p = 0.01), diabetes mellitus (p = 0.05), valvular heart disease (p = 0.05), and thyroid dysfunction (18.3% vs 1.8%, p < 0.001). AF males had higher rate of coronary artery disease (p < 0.001) and heart failure with reduced ejection fraction (p < 0.001). Females were managed with rate control medications more frequently than with antiarrhythmic (p < 0.001). After adjusting gender to age and comorbidities, females continued to have higher rates of heart failure hospitalization (Odds Ratio (OR) 2.73 95% Confidence Interval (CI) 1.04-5.89, P-value <0.001) and recurrent AF (OR 3.86, P-value=0.02). Thyroid dysfunction and the lack of antiarrhythmic treatments significantly increased the risk of AF (OR 5.95 95% CI 3.15-9.73, OR 3.42, respectively, P-value <0.001 for both) regardless of gender. The mortality rate differs only in a sub-group of females ≥75 years of age (OR 1.60, P < 0.001). Conclusion: AF males and females differ significantly in baseline characteristics and tend to be treated unnecessarily differently for AF. Heart failure hospitalizations and recurrent AF continued to be associated with female AF patients, even after adjusting gender to age and comorbidities. Thyroid dysfunction and AF treatment may explain the higher rates of recurrent AF in female patients.