Abstract Body (Do not enter title and authors here): Introduction: Obesity is one of the main causes of heart failure (HF) and atrial fibrillation (AF), respectively. Sarcopenic obesity is prevalent in patients with HF and is associated with poor clinical outcomes. Creatine kinase (CK) is an enzyme that provides ATP for contraction in muscle, and serum CK is readily available in daily clinical practice and is reported to reflect amount of muscle and physical activity. However, little is known about the association of serum CK with HF in obese patients with AF.
Methods: The Fushimi AF Registry, a community-based prospective survey, was designed to enroll all of the AF patients in an urban community in Japan. Follow-up data were available for 4,496 patients as of February 2022, and the median follow-up period was 2,096 days. Of them, we excluded 1,407 without serum CK data at baseline. We divided 789 obese patients (criteria for Japanese people; BMI 25 kg/m² or above) into two groups according to serum CK level (low CK:<59 IU/l in male, <41 in female; n=116,non-low CK; n=673), and compared the baseline clinical characteristics and incidence of hospitalization for HF.
Results: Low CK group was older (low CK vs. non-low CK; 74.7±10.3 vs. 70.8±10.7 years; p<0.01), had more prevalence of diabetes (44.8 vs.32.1 %; p<0.01) and anemia (19.0 vs.8.8 %; p<0.01) and higher CHA₂DS₂-VASc score (3.85±1.62 vs. 3.31±1.64; p<0.01) than non-low CK groups. Sex, BMI, systolic blood pressure, pulse rate, paroxysmal AF, prevalence of hypertension, chronic kidney disease and organic heart disease, the prescription of oral diuretics, prior catheter ablation, brain natriuretic peptide level, left ventricular ejection fraction and left atrial diameter were comparable between the groups. During the median follow-up period of 2,542 days, 150 hospitalizations for HF occurred. In Kaplan-Meier analysis, the incidence of HF was higher in low CK group (5.72 vs. 2.95 per 100 person-years; p=0.001, by log-rank test) (Figure). Low CK (hazard ratio [95% confidential interval]: 2.20 [1.22–3.96]; p<0.01) was an independent predictor of the incidence of hospitalization for HF after adjustment by age, left atrial diameter, brain natriuretic peptide level and the components of H₂ARDD score (Am J Cardiol 2012;110:678-682.) (Table).
Conclusions: Low CK was independently associated with incidence of hospitalization for HF among Japanese obese patients with AF.