Detecting Heart Disease Using First Pass Imaging With Gated SPECT Perfusion
Condition: Ischemic Heart Disease
MeSH terms: Heart Diseases; Myocardial Ischemia; Coronary Artery Disease
Study type: Observational

Summary: 
      The aim of this study is to determine if stress first pass imaging in conjunction with a
      nuclear scan will improve the sensitivity for detecting heart disease. This study will also
      test the usefulness of a nuclear medicine camera, CDLCAM One Pass Angiography system.
    

Detailed description: 
      In this clinical trial, patients with suspected or previously diagnosed coronary artery
      disease who are clinically referred for either a treadmill exercise stress/rest SPECT study
      or a vasodilatation stress/rest SPECT study will be considered for this protocol. The
      vasodilation study may be either adenosine or regadenosin. In addition to the stress study, a
      stress/rest echocardiography study and first pass image will also be obtained. The reason to
      include echocardiography is to provide an independent measurement of the ejection fraction
      during pharmacological stress for comparison to the ejection fraction from the first pass
      study and from the ECG-gated SPECT study performed at rest. This will evaluate the added
      value of calculation of stress left ventricular ejection fraction (LVEF) over gated SPECT
      resting EF. This information will also assist in evaluating LV dysfunction following
      induction of pharmacological stress Nuclear imaging compared with echocardiographic stress
      EF, established imaging modalities for assessment of coronary heart disease.

      The study will include two ECHO imaging sessions and two SPECT imaging sessions.

      Patients will undergo a resting first pass image during the administration 99mTc-tetrofosmin;
      and a resting ECHO study at an appropriate imaging time. The resting ECHO will also be used
      to assess patient imaging window quality and to optimize equipment settings for subsequent
      stress images. A rest gated-SPECT image will be acquired at the appropriate imaging time.

      The patient will then undergo a standard vasodilation stress infusion. A first pass image
      will be obtained during the administration of 99mTc-tetrofosmin. An ECHO will be obtained
      prior to the completion of the infusion. A gated-SPECT study will then be performed at the
      appropriate imaging time.

      Tetrofosmin ECG-gated SPECT Imaging:

      One hundred patients will be enrolled in the vasodilation stress/rest ECG-gated SPECT
      myocardial perfusion imaging group. Imaging time for each session will vary from one and a
      half to three hours. A one or two day imaging protocol can be utilized. Depending on what
      imaging session is done first (rest or stress), a "one-day" protocol consists of having the
      first dose of 99mTc-Tetrofosmin as a low dose of 10-15mCi. The second dose will be the high
      dose of 20-40mCi depending on the patient's weight. In the "two-day" protocol, patients will
      receive a high dose of 99mTc-Tetrofosmin for both imaging sessions. The dose given will
      depend on the patient's weight.

      Rest Imaging:

      If venous access is not already established, the standard universal precautions and 18-20
      gauge catheter equipped with a 3-way stopcock will be inserted preferably in the antecubital
      vein. The patient will be injected with the appropriate amount of 99mTc-Tetrofosmin. The
      first pass image will be acquired during the injection (see first pass protocol). An Early
      resting gated-SPECT imaging and an ECHO will be done at 15 minutes and then repeated at 60
      minutes (see ECHO protocol).

      Adenosine Imaging:

      If venous access is not already established, the standard universal precautions and 18-20
      gauge catheter equipped with a 3-way stopcock will be inserted preferably in the antecubital
      vein. Patients will receive an infusion of adenosine at a rate of 140ug/kg/min. After 1.5
      minutes of adenosine infusion, the appropriate dose of 99mTc-Tetrofosmin will be injected and
      adenosine infusion will continue for 4.5 additional minutes, in compliance with the standard
      6-minute infusion protocol and current ASNC guidelines. The first pass image will be acquired
      during the injection (see first pass protocol). Blood pressure and heart rate will be
      documented every minute. 12 lead ECG will be obtained at baseline and printed once a minute.
      There will be continuous monitoring of ECG and symptoms throughout the infusion. The ECHO
      will be acquired at 2.5 min of adenosine infusion (see ECHO protocol). An Early resting
      gated-SPECT imaging and an ECHO will be done at 15 minutes post infusion and then repeated at
      60 minutes.

      Test Termination End Points (standard criteria)

        -  Symptomatic hypotension, bradycardia or high degree AV Block

        -  Severe shortness of breath or wheezing

        -  Completion of protocol

        -  ST Segment depression >2mm (horizontal or downsloping)

        -  Angina

        -  Life threatening arrhythmia

        -  Subject requests to stop

      Regadenoson Imaging:

      If venous access is not already established, the standard universal precautions and 18-20
      gauge catheter equipped with a 3-way stopcock will be inserted preferably in the antecubital
      vein.

      Patients will receive an infusion of Regadenoson (0.4 mg regadenoson) by rapid intravenous
      injection; followed immediately by 5 ml saline flush. 20-40 seconds after the saline flush
      Tetrofosmin is injected and a first pass image is done.

      Patients will receive an infusion of Regadenoson at a rate of (0.4 mg regadenoson). After 1.5
      minutes of Regadenoson infusion, the appropriate dose of 99mTc-Tetrofosmin will be injected
      and Regadenoson infusion will continue for 4.5 additional minutes, in compliance with the
      standard 6-minute infusion protocol and current ASNC guidelines. The first pass image will be
      acquired during the injection (see first pass protocol). Blood pressure and heart rate will
      be documented every minute. 12 lead ECG will be obtained at baseline and printed once a
      minute. There will be continuous monitoring of ECG and symptoms throughout the infusion. The
      ECHO will be acquired at 2.5 min of Regadenoson infusion (see ECHO protocol). An Early
      resting gated-SPECT imaging and an ECHO will be done at 15 minutes post infusion and then
      repeated at 60 minutes.

      Test Termination End Points (standard criteria)

        -  Symptomatic hypotension, bradycardia or high degree AV Block

        -  Severe shortness of breath or wheezing

        -  Completion of protocol

        -  ST Segment depression >2mm (horizontal or downsloping)

        -  Angina

        -  Life threatening arrhythmia

        -  Subject requests to stop

      Treadmill Exercise (Stress) Imaging:

      If venous access is not already established, the standard universal precautions and 18-20
      gauge catheter equipped with a 3-way stopcock will be inserted preferably in the antecubital
      vein. Patients will follow a preset treadmill protocol. ECG's will be continuously monitored
      during exercise and are printed out for each stage of exercise. Patients will be injected
      with the appropriate amount of 99mTc-Tetrofosmin. The first pass image will be acquired
      during the injection (see first pass protocol). Due to logistical difficulties, the ECHO will
      not be performed for this imaging session.

      Test Termination End Points (standard criteria)

        -  Severe Fatigue

        -  ST segment depression or elevation >2mm (horizontal or downsloping)

        -  Severe Angina

        -  Severe Shortness of breath/ wheezing

        -  Significant drop (20mmHG) in blood pressure

        -  Significant elevation of blood pressure:

        -  Systolic :> 220mmHG

        -  Diastolic :> 120mmHG

        -  Severe lower extremity discomfort

        -  Signs of severe peripheral circulatory insufficiency: lightheadedness, nausea, pallor

        -  Onset of second or third degree AV Block

        -  Ventricular Tachycardia

        -  Symptomatic SVT

        -  Patient request to stop

        -  Completion of Protocol

        -  For a Nuclear Imaging Study, patient should reach 85% of age predicted maximum heart
           rate prior to the injection of radioisotope (220-age). Once target is reached then the
           isotope is injected and patient should exercise for 2 more minutes post injection

      Echocardiography Imaging:

      Instrument settings will be optimized to ensure the best delineation of the endocardial
      borders of the left ventricle. Rest ECHO will be obtained in the standard protocol for both
      imaging groups. Patients in the adenosine vasodilatation stress group will have an ECHO
      during the infusion of adenosine in the standard views. Patients in the exercise stress group
      will have an ECHO immediately after exercise in the standard views. Patients in both groups
      will have an ECHO 15 minutes and 60 minutes after stress.

      2D and 3D- Echocardiography Views

      Primary views:

        -  Apical four chamber 2D view (2D and color tissue Doppler)

        -  Apical two chamber 2D view (2D and color tissue Doppler)

        -  Apical 3D view

      Secondary 2D views:

        -  Parasternal short axis at base, mid and apex of LV (2D and color tissue Doppler)

        -  Parasternal long axis

      First Pass Radionuclide Angiography:

      Patients are prepped as outlined previously including IV placement. For the resting image,
      patients are connected to the camera gate device for continuous registration of the ECG.
      Patients will be placed against the face of the camera to begin isotope infusion. The camera
      will detect the presence of the isotope within the SVC and initiate recording of the data;
      real time acquisition progress will be displayed on the computer screen.

      During the acquisition for the treadmill exercise image, patients will be connected to the
      camera gate device for continuous registration of the ECG. Patients are placed against the
      face of the camera. The height of the camera is set to the patient and "Treadmill tracking"
      is set to the "ON" position. At peak exercise, the isotope is injected. The camera will
      detect the presence of the isotope within the SVC and initiate recording of the data; real
      time acquisition progress is displayed on the computer screen.

      During acquisition for the adenosine vasodilatation image, patients are connected to the
      camera gate device for continuous registration of the ECG. Patients are placed against the
      face of the camera. The isotope is infused at 1.5 minutes of adenosine infusion. The camera
      will detect the presence of the isotope within the SVC and initiate recording of the data;
      real time acquisition progress is displayed on the computer screen.

      The total image time for the first pass study is 30 seconds.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        All patients with suspected or previously diagnosed coronary artery disease that are
        clinically referred for either a treadmill exercise stress/rest SPECT study or an adenosine
        vasodilatation stress/rest SPECT study will be considered for this protocol. Efforts will
        be made to enroll equal numbers of men and women for this clinical study.