The role of Life’s Essential 8 and multimorbidity in the risk of new-onset atrial fibrillation: observations from a large prospective cohort study

BACKGROUND: The risk of atrial fibrillation (AF) is accentuated by age and comorbidities. Healthy lifestyle behaviors, based on Life's Essential 8 (LE8), may modify the risk of new-onset AF mitigating the impact of multimorbidity. The aim of this study was to investigate the associations of LE8 with multimorbidity status, linked to AF incidence. METHODS: A total of 255 280 participants free of AF were included. LE8 was assessed using eight metrics and categorized into low, moderate, and high cardiovascular health (CVH). Multimorbidity clusters were determined using latent class analysis using 36 long-term conditions (LTCs), categorized into five groups as follows: three multimorbidity clusters (noncardiovascular disease; mental health; and cardio-metabolic multimorbidity); no LTCs; and singular LTCs. The relationships between LE8 and multimorbidity status with AF incidence were evaluated using Cox models and counterfactual analyses. RESULTS: During an average follow-up of 11.7 years (SD 2.2), 15 069 participants without AF at baseline (mean age 56.2; SD 8.1; 51.9% female and 48.1% male) developed AF. Individuals with high CVH had a 27% lower risk of AF than those with low CVH. Compared to individuals without multimorbidity, participants with singular LTC or multimorbidity clusters had higher AF risk. Up to 54.7% of the associations between multimorbidity status and AF were mediated by LE8. Counterfactual analysis showed increasing the LE8 score to 80 could reduce AF occurrence in multimorbidity individuals by 22.12% to 24.56%. CONCLUSION: Lower LE8 scores and multimorbidity were associated with higher AF incidence. Adherence to a healthy lifestyle, based on LE8 may prevent AF, especially in those with multimorbidity.