Echocardiography Management for Patients Requiring Care for Non-Cardiac Surgery
Condition: Cardiovascular Risk Factors
Study type: Interventional

Summary: 
      The growing population of institution patients with heart failure combined with the
      increasing number of surgical procedures performed each year supports the need for a critical
      analysis of how to most appropriately manage these patients during the perioperative period,
      especially for non-cardiac surgery. Echo-guided hemodynamic management (EGHEM) is the use of
      echocardiography data to normalize and/or optimize in real-time, cardiac output and
      ventricular filling pressures in the perioperative period for non-cardiac surgical cases. The
      purpose of this study is to test the hypothesis that EGHEM compared to standard management
      practices will result in a reduced length of hospital stay in the noncardiac surgery
      population. The primary goal of health care providers for patients requiring anesthetic care,
      perioperative care, or critical care is ensuring the adequacy of the patient's circulatory
      function by optimizing cardiac output and ventricular filling pressure. Currently, the use of
      the ECG monitor and systemic blood pressure are the standard of care for assessing
      circulatory function. However, those data cannot provide accurate information on cardiac
      output and ventricular filling pressure for patients with cardiovascular risk factors and/or
      comorbidities. As a result, managing the hemodynamic parameters of these patients, as well as
      their intravenous fluid needs and resuscitation strategy, we hypothesize that using
      traditional approaches may lead to significant volume overload and post-operative
      cardiovascular complications and morbidity. In this study we propose an EGHEM strategy that
      incorporates standard echocardiography generated data points in addition to the systemic
      blood pressure and ECG signal to assess, manage, modify and optimize patient cardiac preload,
      afterload, heart rate and contractility in the perioperative period. Based on our initial
      observations and preliminary data using the EGHEM approach, we hypothesize that we can
      demonstrate a significant decrease in hospital length of stay and an overall decrease in
      perioperative morbidity at 30 days in the non-cardiac surgery population using EGHEM compared
      to standard practices. In this proposal we have designed a single center, prospective,
      randomized clinical trial to test our hypothesis.
    

Detailed description: 
      Step 1: Patient selection

      The first step in the EGHEM/EGAM process is appropriate patient selection. Patients who have
      any of the following cardiovascular risk factors and/or comorbidities and are scheduled for a
      non-cardiac surgery are candidates for EGHEM/EGAM:

        1. Urology/gynecology/General surgical patient

        2. Non-cardiac surgical population

        3. age 65 years or older, OR 19 years or older and one of the following risk factors:

             1. Hypertension (HTN)

             2. Diabetes

             3. Obesity (body mass index [BMI] >35)

             4. Renal insufficiency

             5. Tobacco usage

             6. Hypercholesterolemia

             7. Sleep apnea/heavy snoring at night

             8. Clinical diagnosis of congestive heart failure (CHF) as defined by:

                  -  Dyspnea on exertion

                  -  Paroxysmal nocturnal dyspnea

                  -  Orthopnea

                  -  Elevated jugular venous pressure

                  -  Pulmonary rales

                  -  Third heart sound

                  -  Cardiomegaly or pulmonary edema on chest x-ray

                  -  Peripheral edema

                  -  Hepatomegaly

                  -  Pleural effusion

             9. Palpitations/irregular heart beats

            10. Chest pain at rest and or exercise

            11. Murmur on examination

            12. Known coronary artery disease (CAD)/stents/coronary artery bypass graft (CABG)

            13. Known valvular disease

            14. Known stroke or transient ischemic attacks (TIA) Standard Medical Care Step 2:
                Pre-op assessment

      Step 2 in the EGAM process involves a bedside, transthoracic echocardiography (TTE) pre-op
      assessment. The pre-op TTE should be performed by one of the co-investigators, and take less
      than 10 minutes to complete. The information acquired by TTE during the pre-op assessment
      should include the following five evaluations, in order of importance:

        1. Cardiac output on the left side of the heart using spectral Doppler measurements;

             1. Left ventricular outflow tract (LVOT) velocity time integral (VTI)

             2. Heart rate

        2. Filling pressures on the left side of the heart using spectral Doppler measurements;

             1. The pulmonary venous flow pattern defined as co-dominant, systolic dominant or
                diastolic dominant

             2. The mitral inflow pattern defined as normal, impaired relaxation, pseudonormal or
                restrictive

             3. The E/e' ratio of velocities

        3. Mitral valve structure and function;

        4. Aortic valve structure and function; and

        5. Biventricular contractility.

      These evaluations are performed using the following TTE views:

      A. Parasternal (PS) window: With the patient in the left lateral decubitus position, the TTE
      probe is placed on the 3rd left intercostal space next to the sternum; the light on the probe
      should be directed toward the patient's right shoulder. The 2-dimensional image of the long
      axis (LAX) should be acquired first. In this view, the following are evaluated:

        -  Color Doppler on aortic valve (AV) and mitral valve (MV)

        -  E-point septal separation (EPSS) To evaluate the PS short axis (SAX), the probe should
           be rotated clockwise 60 degrees. The 2-dimensional view should be obtained at the
           mid-papillary level.

      B. Apical window: With the patient in the same left, lateral, decubitus position, the probe
      is placed between the 5th and 6th intercostal space on the left side, close to the nipple
      line. The light on the probe should be directed toward the floor or the bed for the 4-chamber
      view. The following assessments should be performed in the 4-chamber view:

        -  Two-dimensional image;

        -  Pulsed-wave (PW) Doppler in the right upper pulmonary vein;

        -  PW Doppler at the tip of the MV;

        -  PW Doppler on the MV annulus for tissue Doppler;

        -  Color Doppler on the tricuspid valve (TV) and MV if necessary based on the PS LAX
           window.

      For the apical LAX, the probe should be rotated counterclockwise so that the light is
      directed toward the patient's right shoulder. In the LAX view, velocity time integrals (VTIs)
      using PW in the left ventricular outflow track (LVOT) and continuous wave (CW) at the level
      of the AV should be acquired.

      C. Subcostal window: With the patient supine, the TTE probe is placed under the right costal
      ridge and directed toward the heart. The light should be directed toward the sonographer
      (toward the patient's left) to assess the 4-chamber view.

      For the subcostal inferior vena cava (IVC) view, the probe should be slightly rotated
      counterclockwise until the IVC can be assessed.

      Standard Medical Care Step 3: Management strategies Step 3 in the EGHEM/EGAM process is to
      define patient management strategies based on the pre-op TTE assessment. The main goals of
      patient management are to maintain normal cardiac output and filling pressure. Primary and
      secondary findings and the associated EGAM strategies to achieve these goals are outlined in
      Table 1 and Table 2, respectively.

      Table 1: Primary findings and associated management strategy to maintain normal cardiac
      output and filling pressure.

      Echo-Generated Findings EGHEM/EGAM Strategy Cardiac output status Filling pressure status
      Normal High Preload reduction Low Normal Afterload reduction Low High Afterload and preload
      reduction High High Preload reduction High Normal or low Increase preload

      Table 2: Secondary findings and associated management strategy to optimize patient
      management.

      Echo-Generated Finding EGHEM/EGAM Strategy Filling Pressure Other High Aortic stenosis
      Preload reduction Normal Aortic stenosis Safe for afterload reduction

        -  Mitral regurgitation Afterload reduction

        -  Low contractility Inotropic support

        -  Suspected or confirmed CAD Maintain heart rate in the 50 - 60 bpm range right ventricle
           (RV) volume overload Preload reduction RV pressure overload Pulmonary afterload
           reduction Standard Medical Care Step 4: Ongoing intra-operative assessment Based on the
           appropriate EGAM strategy defined in Step 3, either TEE or TTE should be used during the
           surgical procedure for the ongoing patient assessment every 15 to 20 minutes. The PI or
           Secondary Investigator will determine whether a TEE or TTE should be conducted
           intra-operatively. The results of these tests will be used for research purposes. During
           surgery: fluid administration, afterload adjustments, and supported contractility can be
           implemented to optimize patient management. It is difficult to assess cardiac output
           with the current standard medical care without invasive monitoring. There is minimal
           risk if the physician gets distracted by the echocardiogram or the algorithm of the
           study however it is unlikely this tool would be a distraction to the physician as it is
           monitoring the patient.
    

Intervention name(s): Transthoracic Echocardiogram (TTE)/Transesophageal Echocardiogram (TEE)
Intervention type(s): Procedure
Intervention description(s): Duration lasts the entire operation.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: congestive heart failure