Clinical characteristics of nonobese patients with acute coronary syndrome and increased epicardial fat volume

Aim: Increased epicardial fat volume (EFV) is an independent risk factor for acute coronary syndrome (ACS). Although EFV increases with body mass index (BMI), some ACS patients have an increased EFV but normal BMI. We here investigated the clinical characteristics of nonobese ACS patients with an increased EFV. Methods: A total of 197 Japanese patients hospitalized for ACS was evaluated for EFV, abdominal visceral fat area (VFA), and lipid and glucose profiles. Control subjects comprised 141 individuals who were suspected of having ACS but whose coronary computed tomography findings were normal. Results: EFV was increased in ACS patients compared with control subjects (120±47 versus 95±45 mL, P＜ 0.01). ACS patients were divided into four groups based on average EFV (120 mL) and a BMI obesity cutoff of 25 kg/m ² . For the 30 nonobese ACS patients with an above-average EFV, EFV was positively correlated with VFA (r =0.23, P =0.031). These individuals were significantly older (74±10 years) and tended to have a higher homeostasis model assessment – insulin resistance value (5.5±3.8) compared with other ACS patients. Among nonobese study subjects, EFV was independently associated with ACS (odds ratio=2.01, P =0.021) and correlated with abdominal circumference (r =0.26, P =0.017). Conclusion: Nonobese ACS patients with an increased EFV were elderly and tended to manifest insulin resistance. Measurement of EFV may prove informative for evaluation of ACS risk among elderly nonobese individuals with an increased abdominal girth.