FAST study demonstrated OptiVolฎ was more accurate than daily weight monitoring in predicting worsening heart failure1
Fluid Accumulation Status Trial (FAST) n = 156 patients
The Fluid Accumulation Status Trial (FAST) study was a multicenter, prospective, double-blinded
investigation of the clinical utility of a fluid index derived from intrathoracic impedance measurements (OptiVol).
Each device recorded daily changes in intrathoracic impedance
Daily impedance changes were used to calculate a reference impedance and a fluid index
Subjects recorded daily weight in a diary
Sensitivity was determined by the number of adjudicated heart failure events, including hospitalizations, emergency room visits, urgent care, or unscheduled office visits occurring within 30 days of a fluid index threshold crossing or an acute gain
in weight, divided by the total number of adjudicated heart failure events.
Unexplained detections were defined as threshold crossings or acute weight gains not associated with an HF event
(76.4%) was significantly greater than weights
(22.5%) for detecting worsening heart failure
OptiVols unexplained detection rate
(1.9/pt/yr) was significantly lower than acute weight increases
Impedance measurements were performed on greater than 99% of the follow-up days versus 76% of days for weights
OptiVol Detected Three Times More Future HF Events than Weight Monitoring Alone