Introduction: Heart failure (HF) is a common condition affecting the aging population with different clinical characteristics in men and women. There is accumulated evidence regarding gender differences in risk factors, pathophysiological mechanisms, substrate and comorbidities, in patients with HF.

Objective: To compare the differences in women and men with HF and atrial fibrilation (AF) with regard to clinical characteristics and left ventricular ejection fraction (LVEF).

Methods: We conducted a retrospective study in a tertiary University Hospital between January 2018 to July 2019. We included all the patients admitted consecutively with HF and AF. Readmissions were excluded. In order to assess the comorbidities we have used Charlson comorbidity index, including age, the history of myocardial infarction (MI), chronic HF, peripheral arterial disease (PAD), cerebrovascular accident (CVA), dementia, chronic obstructive lung disease (COPD), connective tissue disease, peptic ulcer disease, liver cirrhosis (LC), diabetes mellitus (DM), chronic kidney disease (CKD), solid tumor, leukemia, lymphoma, AIDS. HF was classified as HF with preserved ejection fraction (HFpEF), HF with mid-range ejection fraction (HFmrEF) and HF with reduced ejection fraction (HFrEF).

Results: 624 patients with HF and AF with a mean age of 72.60 ± 10.23 years were included. 52.88% were female. 48.86% had HFpEF, 21.48% HFmrEF and 29.66% HFrEF. Women tend to be older (74.26 ± 9.16 vs. 70.74 ± 11.03 years, p< 0.001) with higher LVEF (47.26 ± 11.85 vs. 40.58 ± 14.63%, p< 0.001) and more often had HFpEF (57.86% vs. 38.62% of men (p< 0.001)), while men had HFrEF (40.65% vs. 20% of women (p< 0.001)). There was not a significant difference in the Charlson scores (5 vs. 5 points, p= 0.54). Men were more often associated with MI (15.12% vs. 7.60%, p= 0.004), PAD (7.93% vs. 3.94%, p= 0.05), DM (36.08% vs. 27.88%, p= 0.03), COPD (7.59% vs. 4.27%, p= 0.07), LC (4.45% vs. 1.52%, p= 0.05), and solid malignancy (16.10% vs. 7.88%, p= 0.002). Women more often were hypertensive (82.73% vs. 76.29%, p= 0.05) and dyslipidemic (49.70% vs. 39.86%, p= 0.017).

Conclusions: Gender differences are reflected in both the type of heart failure as well as the type of associated comorbidities. Women are far more likely to be diagnosed with HFpEF and to have more prevalent risk factors for cardiovascular disease, however without overt coronary artery disease. On the other hand, the prevalence of HFrEF appears to be higher among men, while associating a history of previous MI or PAD, as well as more non-cardiovascular comorbidities.