From the Guidelines
Myocardial perfusion imaging (MPI) is a recommended non-invasive diagnostic tool for detecting coronary artery disease (CAD) in individuals with suspected chronic coronary syndrome and moderate or high pre-test likelihood of obstructive CAD, as stated in the 2024 ESC guidelines 1.
Key Points
- MPI is useful for diagnosing and quantifying myocardial ischemia and/or scar, estimating the risk of major adverse cardiac events (MACE), and quantifying myocardial blood flow (PET) 1.
- The test is typically performed both at rest and during stress (either exercise or pharmacological stress), allowing for comparison between normal and stressed states.
- MPI has good sensitivity and specificity for detecting significant CAD, making it particularly useful for patients with intermediate pretest probability of CAD, those unable to exercise adequately for stress ECG testing, and for risk stratification after myocardial infarction.
Recommendations
- In individuals with suspected CCS and moderate or high (>15%–85%) pre-test likelihood of obstructive CAD, stress SPECT or, preferably, PET myocardial perfusion imaging is recommended to diagnose and quantify myocardial ischemia and/or scar, estimate the risk of MACE, and quantify myocardial blood flow (PET) 1.
- CMR perfusion imaging is also recommended to diagnose and quantify myocardial ischemia and/or scar and estimate the risk of MACE in individuals with suspected CCS and moderate or high pre-test likelihood of obstructive CAD 1.
Additional Considerations
- Newer-generation SPECT cameras based on cadmium–zinc–telluride (CZT) semiconductor detector technology enable a substantial reduction in radiation dose exposure and acquisition time, as well as an increased diagnostic accuracy 1.
- Hybrid SPECT/coronary CT angiography (CCTA) combines the anatomic information provided by CT with the functional perfusion evidence of SPECT, resulting in enhanced diagnostic accuracy for detecting significant CAD compared with SPECT and CCTA alone 1.
From the FDA Drug Label
INDICATIONS AND USAGE CARDIOLITE® is a myocardial perfusion agent indicated for: (1) detecting coronary artery disease by localizing myocardial ischemia (reversible defects) and infarction (non-reversible defects) evaluating myocardial function and developing information for use in patient management decisions INDICATIONS AND USAGE CARDIOLITE is a myocardial perfusion agent indicated for: (1) detecting coronary artery disease by localizing myocardial ischemia (reversible defects) and infarction (non-reversible defects) evaluating myocardial function and developing information for use in patient management decisions
The role of Myocardial Perfusion Imaging (MPI) in diagnosing Coronary Artery Disease (CAD) is to:
- Detect CAD by localizing myocardial ischemia (reversible defects) and infarction (non-reversible defects)
- Evaluate myocardial function
- Develop information for use in patient management decisions 2 2
From the Research
Role of Myocardial Perfusion Imaging in Diagnosing Coronary Artery Disease
- Myocardial perfusion imaging (MPI) plays a significant role in diagnosing coronary artery disease (CAD) and risk stratification 3.
- MPI, including single photon emission computed tomography and positron emission tomography, has been widely employed to evaluate ischemia and myocardial viability 3.
- The test accuracy and clinical significance of MPI methods for diagnosing and managing CAD have been reviewed, and the comparative usefulness of other noninvasive tests, such as stress echocardiography, coronary computed tomography angiography, and cardiac magnetic resonance imaging, have been discussed 3.
Evaluation of Interventions in Coronary Artery Disease
- MPI provides a means for evaluating the effects of interventional therapy in patients with CAD, including those with unstable angina, acute myocardial infarction, and chronic ischemia 4.
- In patients with stable CAD, perfusion imaging has been used to evaluate the efficacy of anti-anginal medications 4.
- MPI can be used to identify areas of jeopardized myocardium and predict the risk of subsequent cardiac events, including myocardial infarction 4.
Myocardial Perfusion Imaging with Cardiac Computed Tomography
- Cardiac computed tomography (CCT) has become an important tool for the anatomic assessment of patients with suspected CAD, and its diagnostic accuracy for detecting underlying CAD is well documented 5.
- The role of CCT for the physiologic assessment of myocardial perfusion during resting and stress conditions is emerging, and with the addition of MPI to coronary imaging, CCT has the potential to assess both coronary anatomy and its functional significance with a single non-invasive test 5.
Diagnostic Value of Myocardial Perfusion Scintigraphy
- Myocardial perfusion scintigraphy is an established method in cardiology for the diagnosis and evaluation of CAD, and Thallium-201 and Tc-99m sestamibi myocardial perfusion imaging has been widely accepted as a non-invasive diagnostic procedure for detection of CAD, risk stratification, and myocardial viability assessment 6.
- The dual-isotope rest Thallium-201/stress Technetium-99m sestamibi gated single-photon emission tomography protocol has gained increasing popularity for these applications, and combining the use of Thallium-201 with Technetium-99m agents permits optimal image resolution and simultaneous assessment of viability 6.
Quantitative Perfusion Imaging
- Quantitative myocardial perfusion imaging is increasingly used for the diagnosis of CAD, and quantitative perfusion imaging allows for the noninvasive calculation of fractional flow reserve (FFR) 7.
- The relative flow reserve (RFR) derived from quantitative perfusion imaging may not outperform stress myocardial blood flow for identification of hemodynamically significant CAD, and the correlation between RFR and FFR is moderate 7.