Bioelectrical impedance analysis in body composition analysis for evaluation of adverse cardiovascular events in patients with acute coronary syndrome

Abstract BACKGROUND Changes in body water composition are linked to poorer outcomes in acute coronary syndrome (ACS). Bioelectrical impedance analysis (BIA), a noninvasive test that measures body water, may help assess future risks for patients with ACS. This study assessed BIA's usefulness in diagnosing and predicting outcomes in patients with ACS. MATERIALS: In this cohort, longitudinal, prognostic study, we enrolled 467 patients with ACS. The main outcome of interest was any major adverse cardiac event (MACE) within 1 year, such as all-cause mortality, reinfarction, or heart failure requiring rehospitalization. BIA measurements focused on intracellular and extracellular fluid electrodynamic properties. RESULTS Patients who experienced MACE had higher BIA scores than those without MACE. The Youden index identified an optimal BIA cutoff of 417.5 (log-rank test p < 0.001) for predicting MACE risk. Elevated BIA remained a strong predictor of MACE even after correcting for baseline confounders using one-way regression modeling (HR 2.93, 95% CI 1.98–4.35, p < 0.001) and multifactorial regression analysis (HR 3.95, 95% CI 2.55–6.10, p < 0.001). Combining BIA with a traditional measure (left ventricular ejection fraction [LVEF]) significantly improved the prognostic evaluation (p < 0.05). In addition, the BIA cutoff value allowed for further risk stratification of patients. CONCLUSION BIA is a superior prognostic indicator to LVEF in ACS patients with elevated troponin.