Evaluation of the E/e' Ratio of the Mitral Annulus in Predicting Fluid Responsiveness.

Study Overview
=================
Brief Summary
-----------------
Diastolic function may be evaluated by different measurements on transesophageal echocardiography (TEE). They include mitral inflow velocities obtained by pulsed-wave doppler (PW) : peak early diastolic velocity (E) and late diastolic velocity (A). Mitral annulus velocities, early diastolic (e') and late diastolic (a') are obtained by tissue doppler imaging (TDI). The ratio E/e' reflects left ventricular filling pressure and, as such, might be a predictor of fluid responsiveness. The aim of this study is to evaluate the predictive value of the mitral valve E/e' ratio for fluid responsiveness among patients undergoing coronary bypass graft surgery. Fluid responsiveness being defined as an increase in stroke volume of ≥ 15%. After induction of anesthesia, patients will have their diastolic function evaluated by means of E/e' and other measures. They will then be administered an intravenous bolus of 500 mL of Lactate Ringer® along with passive leg raising (PLR). Stroke volume and fluid responsiveness will be assessed by the thermodilution method (Swan-Ganz catheter) and the FloTrac® device. Fluid responders will be compared to non-responders to evaluate the relationship between E/e' ratio and fluid responsiveness.

Official Title
-----------------
Evaluation of the E/e' Ratio of the Mitral Annulus Measured by Transesophageal Echocardiography in Predicting Fluid Responsiveness.

Conditions
-----------------
Left Ventricular Function Diastolic Dysfunction, Fluid Responsiveness

Intervention / Treatment
-----------------
* Other: Volume expansion


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients >18 yrs, undergoing elective coronary artery bypass grafting or surgery will be included. Exclusion Criteria: Significant mitral valvular heart disease (mitral regurgitation ≥ 2/4 or stenosis) Significant right sided valvular heart disease (tricuspid regurgitation ≥ 2/4) Intracardiac shunts Emergency surgery Non-sinusal rythme Clinical evidence of decompensated heart failure Clinical evidence of decompensated pulmonary hypertension Renal insufficiency with creatinine clairance ≤ 30 cc/min or dialysis Contraindications to TEE, including esophageal disease or unstable cervical spine CVP ≥ 15 mm Hg or PCWP ≥ 18 mm Hg immediately before fluid infusion

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Volume expansion|Volume expansion with rapid administration of 500 ml of crystalloid|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mitral valve E/e' ratio for prediction of fluid responsiveness | TEE evaluation of mitral inflow velocities and mitral annulus velocities measured right before fluid administration as a predictor of fluid responsiveness defined as an increase of 15% or more of the stroke volume | TEE images taken within the 15 minutes before fluid administration and responsiveness evaluation within the 5 minutes following fluid administration and leg raising | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pulmonary capillary wedge pressure (PCWP) a-wave to v-wave ratio of the for prediction of fluid responsiveness | a-wave on v-wave ratio of the pulmonary capillary wedge pressure (PCWP) curve for prediction of fluid responsiveness defined as an increase of 15% or more of the stroke volume | Waveform measured within the 15 minutes preceding fluid administration and responsiveness evaluation within the 5 minutes following fluid administration and leg raising | 
| Pulse pressure variation (PPV) for prediction of fluid responsiveness | Pulse pressure variation (PPV) measured on arterial pressure curve for prediction of fluid responsiveness defined as an increase of 15% or more of the stroke volume | PPV measured within the 15 minutes preceding fluid administration and responsiveness evaluation within the 5 minutes following fluid administration and leg raising | 
| Stroke volume variation (SVV) for prediction of fluid responsiveness | Stroke volume variation (SVV) directly measured by FloTrac/Vigileo® with its intrinsic algorithm for prediction of fluid responsiveness defined as an increase of 15% or more of the stroke volume | SVV measured within the 15 minutes preceding fluid administration and responsiveness evaluation within the 5 minutes following fluid administration and leg raising |