Abstract MP12: Dietary Fatty Acids and Risk of Incident Atrial Fibrillation in the Women’s Health Study

Abstract

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia and a major risk factor for stroke, heart failure and mortality. Dietary fats may have effects on biologic pathways involved in inflammation, fibrosis, and cellular electrophysiology that influence the development and maintenance of AF. Prior studies evaluating the relationship between N-3 polyunsaturated fats and total AF events have had inconsistent results. Furthermore, few studies have reported the association between other dietary fats and incident AF or whether associations might differ by AF pattern. Methods: We followed 33,041 initially healthy women from the Women's Health Study, who were >45 years and free of AF at baseline in 1993. Intake of individual fats was calculated from a food frequency questionnaire administered at baseline. Self-reported AF was confirmed by EKG and medical record review. We defined AF patterns as paroxysmal (self-terminating for <7 days and no cardioversion), persistent (sustained >7 days and/or required cardioversion) and chronic (cardioversion failed / not attempted). Patterns were classified according to the most severe pattern within 2 years of AF onset and we combined persistent and chronic AF for analysis. We used isocaloric multivariable Cox proportional hazards models, adjusting for diet, lifestyle and clinical CVD risk factors, with a competing risk framework to evaluate whether dietary fats share equal associations across various AF patterns. Results: We documented 1286 cases of AF (821 paroxysmal & 423 persistent/chronic) over a median follow-up of 17.4 years. There was no significant association between any dietary fat and risk of incident AF. Saturated fat was associated with higher risk, and monounsaturated fat with lower risk of persistent/chronic AF. The RR (95%CI) for a substitution of 5% of energy from saturated fat for an equal percentage of energy from carbohydrates was 1.47 (1.02, 2.12) for persistent/chronic AF and 0.84 (0.64, 1.10) for paroxysmal AF (p, diff = 0.01). For monounsaturated fat, the RR for a 5% increment was 0.67 (0.45, 0.98) for persistent/chronic AF and 0.86 (0.73, 1.27) for paroxysmal AF, although the difference between patterns did not reach significance (p, diff = 0.12). Intake of N-3 and n-6 polyunsaturated fat and trans fat were not differentially associated with risk of paroxysmal or persistent/chronic AF. Conclusions: We observed no association between subclasses of dietary fat intake and total AF risk. Saturated fat was positively and monounsaturated fat was inversely associated with risk of persistent/chronic AF. Thus, improving dietary fat quality may help in the prevention of sustained forms of AF, which are often less amenable to treatment and associated with higher rates of morbidity. These results support AHA dietary guidelines to decrease intake of saturated fat for overall cardiovascular health.