Comparison of device-based and bioelectrical impedance methods for volume status assessment in heart failure patients with cardiac implantable electronic devices (CIED vs. BIA fluid assessment in heart failure).

BACKGROUND

Accurate assessment of volume status is essential in heart failure (HF). This study evaluated the association between cardiac implantable electronic device (CIED)-derived fluid monitoring and bioelectrical impedance analysis (BIA) for systemic volume assessment.

METHODS

In this prospective cross-sectional study, 57 patients with HF carrying implantable cardioverter-defibrillators or cardiac resynchronization therapy devices with intrathoracic impedance-based fluid monitoring were enrolled. Patients were classified according to the presence of device-detected fluid alerts. Body composition and total body water (TBW) percentage were assessed by BIA (Tanita). Clinical, laboratory, echocardiographic, and device-derived data were compared. Logistic regression identified variables independently associated with fluid alerts.

RESULTS

Patients with device-detected fluid alerts had higher TBW and lower body fat percentages than those without alerts (both p < 0.001). TBW showed a strong positive correlation with device-detected fluid alerts (r = 0.675, p < 0.001). A TBW threshold of 57.15% predicted fluid alerts with 80% sensitivity and 80% specificity (AUC 0.938, 95% CI 0.856-0.999; p < 0.001). Patients with fluid alerts also demonstrated more pronounced echocardiographic signs of right-sided congestion. In multivariable analysis, TBW remained the only independent predictor of device-detected fluid alerts (OR 1.33, 95% CI 1.07-1.66; p = 0.011).

CONCLUSION

BIA-derived TBW was strongly associated with device-detected fluid alerts and may serve as a practical complementary method for systemic volume assessment, particularly when device-based fluid monitoring is unavailable.