Multi-Center Evaluation of Feasibility of SPECT Measurement of Myocardial Blood Flow and Reserve
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ClinicalTrials.gov Identifier: NCT03427749
Recruitment Status : Unknown
Verified September 2021 by Terrence Ruddy, Ottawa Heart Institute Research Corporation. Recruitment status was: Recruiting
Patients will be recruited from those referred to the local site's Diagnostic Imaging Department for SPECT myocardial perfusion imaging (MPI) ,who have an intermediate to high pre-test likelihood of disease (Diamond-Forrester criteria ≥ 30%) and are clinically indicated to have an MBF study.
Condition or disease
Coronary Artery Disease
Patients will be recruited from those referred to the local site's Diagnostic Imaging Department for SPECT myocardial perfusion imaging (MPI), who have an intermediate to high pre-test likelihood of disease (Diamond-Forrester criteria ≥ 30%) and are clinically indicated to have an MBF study. Research imaging will consist of a SPECT acquisition at the time of rest and stress radiotracer injection in addition to the standard (delayed) clinical stress/rest SPECT scan with 99mTc-tetrofosmin. This is an observational study; patients will be managed according to the standard clinical care of the local site. Where available, a CT scan will also be acquired for attenuation and/or scatter correction. Studies may be one day (rest/stress or stress/rest) or two day (rest and stress on separate days) All studies will be analyzed locally but the raw data will also be anonymized and forwarded to the core facility for reprocessing. Central processing will allow comparison between sites and the repeat processing will provide an estimate of inter-operator variability in the measurements. The core lab will also compare the relative perfusion from immediate and delayed imaging for image quality and diagnostic accuracy (visual and quantitative).
It is practical to obtain reliable SPECT measurements of MBF routinely within the workflow of a standard clinical practice
MBF reproducibility [ Time Frame: 2 years ]
Global MBF measured at remote sites will agree within 10% with the same data processed at an expert core laboratory.
Secondary Outcome Measures :
Impact on throughput [ Time Frame: 2 Years ]
Routine implementation of a SPECT MBF protocol will have at most minimal impact on patient throughput (defined as <10% reduction in patient volumes).
Delayed imaging [ Time Frame: 2 years ]
Static reconstruction of the last 6 min of the dynamic acquisition will provide images that are clinically equivalent (less than 10% change in patient diagnosis from normal (summed stress score < 4) to abnormal or vice versa), compared to standard static images obtained following a 45-min delay post-injection
Half-dose MBF measurement [ Time Frame: 2 years ]
The difference between MBF measurements with full-data and half-data dynamic acquisitions will be less than or equal to the inter-observer variation in MBF measurements with full-data
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Layout table for eligibility information
Ages Eligible for Study:
18 Years and older (Adult, Older Adult)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
The study population will be adult male and female patients who are referred to the outpatient cardiology clinics and/or the non-invasive Diagnostic Imaging Department at the local site, have known or suspected CAD and are deemed to clincally require MBF measurements.
Age ≥ 18 years old
BMI ≤ 40 kg/m2
Able and willing to comply with the study procedures
Written informed consent
Intermediate to high probability of CAD
Suspected or known CAD on a stable medication regime
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 within 45 days after consent (early revascularization)
Percutaneous coronary intervention (PCI) within 30 days prior to screening or within 45 days following consent (early revascularization)
Recent use of dipyridamole, dipyridamole-containing medications (e.g. Aggrenox)
Known hypersensitivity to dipyridamole or adenosine
Breastfeeding or pregnancy
Claustrophobia or inability to lie still in a supine position
Unwillingness or inability to provide informed consent