NCT06645327 · Milton S. Hershey Medical Center
SSVC-CI During CABG
(SVC-CI)
What this study is about
To investigate the superior vena cava collapsibility index (SVC-CI), measured via transesophageal echocardiography (TEE), as a marker of fluid responsiveness. Two groups will be compared in this study. Groups will be identified by obtaining cardiac output (CO) by standard means using the TEE or pulmonary arterial catheter (PAC).
View original scientific description
To investigate the superior vena cava collapsibility index (SVC-CI), measured via transesophageal echocardiography (TEE), as a marker of fluid responsiveness. Two groups will be compared in this study. Groups will be identified by obtaining cardiac output (CO) by standard means using the TEE or pulmonary arterial catheter (PAC). Both of these monitors are considered standard for patient's undergoing coronary artery bypass grafting surgery (CABG) and recording initial CO readings. Based on CO, the patient's will be placed in study groups one or two. Participants with normal and mildly reduced left ventricular ejection fraction (LVEF \>40%) for group one and those with moderately to severely reduced LVEF (\<40%) in the second group. Following group separation, we will measure the SVC-CI and CO metric in both groups. The intervention will be an operating room table tilt test (head up and then head down) to artificially simulate giving the patient additional fluid. Before and after table tilt, the SVC-CI and CO will be obtained and measured. The SVC-CI is a mathematical equation determined by distance measurements taken via TEE to identify how much the superior vena cava has collapsed following table tilt. Participants will be considered responders if the CO increases by 12% following intervention. Non responders less than 12% change in CO following intervention. Our hypothesis is that the SVC-CI can differentiate responders vs non-responders with regards to fluid responsiveness with adequate sensitivity and specificity in participants with CAD undergoing isolated CABG. The SVC-CI numerical values for the two groups, responders and non-responders, will calculate a threshold of sensitivity and specificity percentages for future patients undergoing CABG.
Interventions
OTHER
a change in operating room table position, which will mimic an IV fluid bolus
Cardiac Output (CO) measurements will be obtained at two separate time points: prior to sternotomy (opening of the chest) and after separation from cardiopulmonary bypass. Intervention 1. the participant will be placed in the reverse Trendelenburg position (head up) to 15 degrees for 60-90 seconds. CO measurement will be obtained 2. the participant will be transitioned to the Trendelenburg position (head down) to 15 degrees for 60-90 seconds. CO measurement will be obtained
Primary outcome measures
To determine an appropriate cut-off value for the SVC-CI in participants with CAD undergoing isolated CABG to distinguish volume responders from non-responders.
Time frame: 10 minutes of time added to your surgery time.
1. Responders increases by 12% or more following intervention 2. Non responders less than 12% change in CO following intervention.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Participants with CAD undergoing CABG utilizing cardiopulmonary bypass
- Participants who are able to consent for themselves
- Primary language is English
Exclusion criteria
- Age less than 18 years of age
- Participants with CAD undergoing off-pump coronary artery bypass (OP-CAB)
- Severe cardiac valvular pathologies or active congestive heart failure
- Participants in active arrhythmia such as atrial fibrillation and atrial flutter at the time of data collection.
- Participants who are unable to consent for themselves
- Primary language is something other than English
Where
- Hershey, Pennsylvania
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
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How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 7, 2026 · Source of record for eligibility and locations