(513) Comparison of a Noninvasive Cardiac Output Monitor (NICOM) with Simultaneous Transthoracic Echocardiography in Pregnant Women

Thursday, February 9, 2023

4:00 PM – 5:30 PM

Objective: The physiologic changes to the cardiovascular system in pregnant people are considerable and can be more pronounced in those with cardiac disease. In critical care settings, noninvasive hemodynamic monitoring is a valid alternative to pulmonary artery catheterization which has an increased risk for morbidity and mortality. There is limited data on non-invasive cardiac output monitoring in pregnancy. We sought to compare transthoracic echocardiography (TTE) to a non-invasive cardiac output monitor (NICOM, Cheetah™) in pregnant patients with and without cardiac disease.

Study Design: This is a prospective, open label validation study comparing two-dimensional (2D) TTE and NICOM estimations of cardiac output (CO) in each trimester of pregnancy and postpartum. Participants with and without cardiac disease with singleton gestations and no additional co-morbidities were included for comparison. NICOM estimations of CO are derived by thoracic bioreactance and were compared to 2D TTE. For equivalence, an acceptable range mean percentage difference (MPD) was defined as +/- 30%.

Results: Sixty subjects were enrolled, 38 without and 22 with cardiac disease. Heart rate measurements between the two devices were strongly correlated in both groups, while stroke volume and CO measurements showed weak correlation. Comparing techniques, NICOM overestimated CO in both groups. In the group without cardiac disease, MPDs were 52.32%, 49.72%, 49.41%, and 51.91% in the 1st, 2nd, and 3rd trimesters, and postpartum period respectively. In the group with cardiac disease, MPDs were 37.85%, 37.82%, 30.72%, and 51.33%.

Conclusion: NICOM overestimated CO when compared to 2D TTE. MPDs approached, but did not achieve, an acceptable range for equivalence in all trimesters for patients with cardiac disease. The physiologic changes of pregnancy, specifically the mean chest circumference and total body water, may alter the accuracy of CO measurement by NICOM as they are currently estimated. While NICOM has been validated for use in the critical care setting, there is insufficient data at this time for use in pregnancy.

Primary & Presenting Author(s)

Karen L. FLorio, DO MPH (she/her/hers)
Vice Chair of Patient Safety and Quality, Associate Professor
University of Missouri
Lees Summit, Missouri, United States

Coauthor(s)

Emily Williams, BS, MD
University of Missouri-Kansas City
Kansas City, Missouri, United States

DW
Darcy White, BS, RN
Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

TD
Tara Banaszek Daming, MD
University of Missouri-Kansas City
Kansas City, Missouri, United States

Sarah Hostetter, MD
University of Missouri-Kansas City
Kansas City, Missouri, United States

TS
Tabitha L. Schrufer-Poland, MD, PhD
MFM Fellow
University of Missouri-Kansas City
Kansas City, Missouri, United States

RG
Rebecca Gray, BS, MBA, RN
Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

LS
Laura Schmidt, MD
Mid-America Heart Institute, Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

AG
Anna Grodzinsky, MD, MSc
Mid-America Heart Institute, Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

JL
John Lee, MD
Mid-America Heart Institute, Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

VR
Valerie Rader, MD
Mid-America Heart Institute, Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

KS
Kathleen Swearingen, N/A
Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

LN
Lynne Nelson, N/A
Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

AM
Anthony Magalaski, MD
Mid-America Heart Institute, Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States

JS
John Spertus, MD, MPH
Mid-America Heart Institute, Saint Luke's Hospital of Kansas City
Kansas City, Missouri, United States