Accuracy and Trending Ability of Blood Pressure and Cardiac Index Measured by ClearSight System in Patients With Reduced Ejection Fraction

Abstract

To investigate the accuracy and trending ability of ClearSight (Edwards Lifesciences, Irvine, CA) in patients with reduced ejection fraction (<55%) undergoing off-pump coronary artery bypass graft (CABG) surgery by comparing the ClearSight-derived cardiac index (CICS) with the cardiac index measured with thermodilution using a pulmonary artery catheter. In addition, the accuracy and trending ability of ClearSight for blood pressure measurement was investigated by comparing the mean arterial pressure (MAP) derived by ClearSight (MAPcs) with invasive intra-arterial pressure. Prospective clinical study. Cardiac surgery operating room in a single cardiovascular center. The study comprised 20 patients who underwent elective CABG surgery. MAP and cardiac index were measured simultaneously at 6 time points intraoperatively. Trending ability was investigated at the following 2 points: (1) before and after placing the patient in the Trendelenburg position and (2) before and after atrial pacing with a targeted heart rate increase of 20%. Bland-Altman analysis showed that the percentage error between CICS and the cardiac index measured with thermodilution was 40.2% and the percentage error between MAPcs and MAP was 24.6%. Four-quadrant plot analysis showed that the tracking ability of CICS with the Trendelenburg position and atrial pacing was below the good trending ability cutoff (92%). However, the concordance rate of the 4-quadrant plot analysis showed a good trending ability for MAPcs. The polar plot analysis showed the same trend. CICS was not sufficiently accurate in patients with reduced ejection fraction undergoing off-pump CABG surgery. However, ClearSight was clinically acceptable for MAP regarding its accuracy and trending ability in patients with reduced ejection fraction.