Abstract Body: Introduction: Heart failure (HF) and atrial fibrillation/flutter (AF) often cooccur in older adults, the risk factors for which are understudied and was the objective herein.
Method: This prospective cohort study included 31,171 post-menopausal women from the Women’s Health Initiative (WHI) with adjudicated HF merged with Medicare database for AF ascertainment during median follow-up of 17 years. Participants were categorized into 4 groups: no incident AF or HF (n=22,578), with incident AF (n=1,123), with incident HF (n=1,004), and with both incident AF-HF (n=6,466). Baseline exposures evaluated were age, race, obesity, alcohol consumption, smoking, education, income, companionship, physical activity, hypertension, hyperlipidemia, diabetes, and coronary artery disease (CAD). Exposures were compared using multinomial logistic regression model to assess odds ratios (OR) and 95% confidence intervals (CI) for each factor adjusting for the others. The jointly defined referent group was absence of the exposure and no HF or AF.
Result: AF had an incidence proportion of 24.3%, HF 24%, and both AFHF was 20.7%, which is 3.55 times the expected co-incidence. Participants had a mean age of 63.2 (6.9) years at baseline. The odd of incident AF, incident HF and both incident AFHF was higher with older age [OR, 95% CI AF: 1.06 (1.06, 1.07); HF: 1.07 (1.07, 1.09); both AFHF: 1.12 (1.11, 1.13)], obesity [OR, 95% CI AF: 1.26 (1.18, 1.34); HF: 1.55 (1.34, 1.79); both AFHF: 1.72 (1.50, 1.97)], past/ current smoker [OR, 95% CI AF: 1.25 (1.12, 1.39); HF: 2.26 (1.81, 2.81); both AFHF: 1.77 (1.41, 2.24)], higher alcohol std drink/week [OR, 95% CI AF: 1.01 (1.01, 1.02); HF 1.01 (0.99, 1.02); both AFHF: 1.02 (1.01, 1.03)], CAD [OR, 95% CI AF: 1.23 (1.03, 1.47); HF: 2.25 (1.69, 2.99); both AFHF: 2.16 (1.63, 2.86)] and hypertension [OR, 95% CI AF: 1.19 (1.12, 1.27); HF: 1.44 (1.24, 1.67); both AFHF: 1.640 (1.42, 1.88)]. Diabetes was associated with incident HF [OR, 95% CI 2.53 (2.08, 3.08)] and both incident AF-HF [OR, 95% CI 2.03 (1.65, 2.50)] but not with AF alone.
Conclusion: Incident AF, HF are common in older women with their co-incidence 3.55 times higher than expected suggesting a common underlying pathophysiology. Obesity, alcohol consumption, past/ current smoker, hypertension and CAD are major risk factors for AF, HF and their co-occurrence. These findings underscore the importance of targeted interventions to manage these modifiable risk factors to prevent both conditions.