Coronary Heart Disease
Conditions
Brief summary
This study is being done to compare the blood flow measurements obtained with the SPECT and PET imaging scans. Measurements such as myocardial blood flow (MBF) and myocardial flow reserve (MFR) are analyzed on PET scans. These measurements give the doctors more precise information in diagnosing heart problems. SPECT scans, with new camera technology and computer software, now have the potential to also give this additional information. The study is investigating how well the blood flow measurements from SPECT compared to PET.
Detailed description
Absolute myocardial blood flow (MBF) and myocardial flow reserve (MFR) are calculated measurements that are obtained using positron emission tomography (PET) nuclear imaging, from a myocardial perfusion imaging (MPI) stress test, due to the advanced capabilities of the PET camera technology. These calculations provide more diagnostic and prognostic information for patients. Single photon emission computed tomography (SPECT) nuclear imaging is more widely done due to the availability and lower costs, but in the past has not been able to provide the additional information needed to perform the MBF and MFR calculations. SPECT cameras have now been developed and are in use, as well as software for the cameras that have shown that these measurements can be obtained from SPECT. The goal of this study is to compare SPECT and PET measurement of MBF and MFR and determine the reproducibility of SPECT MFR measurements. The study will be done in 3 Phases, with recruitment done over 3 years. Phase 1 and 2 will be done over the first 2 years, with Phase 3 planned following Phases 1 and 2, in the 3rd year of recruitment. Phase 1: patients with coronary artery disease, who are coming to the University of Ottawa Heart Institute (UOHI) for MPI stress testing will have both a PET and SPECT MPI for comparison of the measurements of MBF and MFR. The PET scan will be done as the clinical, reportable test. Phase 2: patients with coronary artery disease, who are coming to UOHI for SPECT MPI testing will have the SPECT repeated to see how reproducible the measurements are. Phase 3: normal, healthy volunteers will have both a PET and SPECT scan for the comparison of the measurements of MBF and MFR. No change to any patient care will be done in Phases 1 and 2. Phase 1 and Phase 2 participants will have 1 research scan and Phase 3 participants will have 2 research scans. Rubidium (Rb-82) Elution System Performance Data will be collected on the elution pump system, used to deliver the Rb-82 isotope, to support the system performance documentation for Health Canada Authorization.
Interventions
OTHERsingle photon emission computed tomography
Single photon emission computed tomography (SPECT) imaging will be done.
Sponsors
GE Healthcare
Ottawa Heart Institute Research Corporation
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
For all participants * Age ≥ 18 years old * BMI ≤ 40 kg/m2 * Able and willing to comply with the study procedures * Written informed consent Participants with intermediate to high probability of CAD * Suspected or known CAD on a stable medication regime. Healthy volunteers without known heart disease * Low risk of CAD (ACC Guidelines Pre-test Probability of Coronary Disease by Symptoms, Gender and Age)
Exclusion criteria
* History or risk of severe bradycardia (heart rate \< 50 beats per minute) not related to chronotropic drugs * Known second- or third-degree AV block without pacemaker * Dyspnea (NYHA III/IV), wheezing asthma or COPD * Coronary artery bypass graft (CABG) surgery within 60 days prior to screening or at any time after consent * Percutaneous coronary intervention (PCI) within 30 days prior to screening or at any time following consent * Acute myocardial infarction or acute coronary syndrome within 60 days prior to screening or at any time following consent * Recent use of dipyridamole, dipyridamole-containing medications (e.g. Aggrenox) * Known hypersensitivity to dipyridamole * Breastfeeding or pregnancy * Claustrophobia or inability to lie still in a supine position * Unwillingness or inability to provide informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Difference Between Measurements of Myocardial Blood Flow Measured With PET and With SPECT | From enrollment to completion of imaging was a maximum of four weeks. The average difference in acquisition dates was 19 +/- 9 days. | PET studies were acquired with either 82Rb or 13N-ammonia according to clinical protocol. The activity injected at both rest and stress was 10 MBq/kg (82Rb) or 5MBq/kg (ammonia). MBF was based on data acquired over 8 min (82Rb) or 4 min (ammonia). SPECT rest images were obtained for 11 min starting immediately before injection of 316 +/- 71 MBq of 99mTc-tetrofosmin. The patient returned at 45 min after injection for a 5 min static resting acquisition (corresponding to the standard time for myocardial perfusion imaging). Without repositioning, the patient was stressed using dipyridamole (0.14mg/kg/min for 5 minutes) with 11 minutes of list mode data acquired starting immediately before the injection of 1122 +/- 170 MBq of tetrofosmin. Both rest and stress injections were delivered mechanically over 30 seconds. A standard set of stress perfusion images were acquired at 45 mins after tracer injection. The myocardial blood flow obtained using SPECT was compared to the patient's PET. |
| Precision of Myocardial Blood Flow Measurements Between Two SPECT Scans | From enrollment to completion of imaging was a maximum of four weeks. | SPECT myocardial blood flow (MBF) was measured and repeated at a mean interval of 18 days to assess precision of MBF measurements between the two scans. |
Countries
Canada
Participant flow
Recruitment details
Recruited 32 patients with known coronary artery disease. Patients were recruited from diagnostic clinic lists.
Pre-assignment details
Enrolled patients who underwent CABG or PCI after they provided consent were excluded from the study. Enrolled patients who experienced acute myocardial infarction or acute coronary syndrome any time after the consent, were also excluded. Enrolled patients with a positive pregnancy screen prior to their research scan were excluded from the study.
Participants by arm
| Arm | Count |
|---|---|
| Single Photon Emission Computed Tomography Myocardial blood flow (MBF) measurement will be analyzed using attenuation and scatter corrected dynamic single photon emission computed tomography (SPECT) imaging data. The data will be compared to MBF obtained from positron emission tomography (PET) imaging.
single photon emission computed tomography: Single photon emission computed tomography (SPECT) imaging will be done. | 31 |
| Total | 31 |
Baseline characteristics
| Characteristic | Single Photon Emission Computed Tomography | — |
|---|---|---|
| Age, Continuous | 64 years STANDARD_DEVIATION 11 | — |
| Race and Ethnicity Not Collected | — | — Participants |
| Region of Enrollment Canada | 31 participants | — |
| Sex: Female, Male Female | 4 Participants | — |
| Sex: Female, Male Male | 27 Participants | — |
| Suspected or known coronary artery disease | 31 Participants | — |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 30 |
| other Total, other adverse events | 0 / 30 |
| serious Total, serious adverse events | 0 / 30 |
Outcome results
Primary
Difference Between Measurements of Myocardial Blood Flow Measured With PET and With SPECT
PET studies were acquired with either 82Rb or 13N-ammonia according to clinical protocol. The activity injected at both rest and stress was 10 MBq/kg (82Rb) or 5MBq/kg (ammonia). MBF was based on data acquired over 8 min (82Rb) or 4 min (ammonia). SPECT rest images were obtained for 11 min starting immediately before injection of 316 +/- 71 MBq of 99mTc-tetrofosmin. The patient returned at 45 min after injection for a 5 min static resting acquisition (corresponding to the standard time for myocardial perfusion imaging). Without repositioning, the patient was stressed using dipyridamole (0.14mg/kg/min for 5 minutes) with 11 minutes of list mode data acquired starting immediately before the injection of 1122 +/- 170 MBq of tetrofosmin. Both rest and stress injections were delivered mechanically over 30 seconds. A standard set of stress perfusion images were acquired at 45 mins after tracer injection. The myocardial blood flow obtained using SPECT was compared to the patient's PET.
Time frame: From enrollment to completion of imaging was a maximum of four weeks. The average difference in acquisition dates was 19 +/- 9 days.
Population: Patients with known coronary artery disease who underwent both PET and SPECT myocardial perfusion imaging within 4 weeks.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Comparision of Myocardial Blood Flow Between PET to SPECT Myocardial Perfusion Imaging. | Difference Between Measurements of Myocardial Blood Flow Measured With PET and With SPECT | 0.06 mean residual difference in MBF | Standard Deviation 0.37 |
Primary
Precision of Myocardial Blood Flow Measurements Between Two SPECT Scans
SPECT myocardial blood flow (MBF) was measured and repeated at a mean interval of 18 days to assess precision of MBF measurements between the two scans.
Time frame: From enrollment to completion of imaging was a maximum of four weeks.
Population: Patients scheduled for clinically indicated SPECT myocardial perfusion studies who had an intermediate to high pretest probability of disease were 18 years of age or older and had a BMI \< 40kg/m2 were recruited to the study.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Comparision of Myocardial Blood Flow Between PET to SPECT Myocardial Perfusion Imaging. | Precision of Myocardial Blood Flow Measurements Between Two SPECT Scans | 29.5 % difference in MBF between SPECT scans | Standard Deviation 1.5 |