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Simultaneous assessment of function and perfusion during dipyridamole-handgrip Tc-99m sestamibi imaging in chronic
T Massardo1, P González, P Humeres
1Nuclear Medicine Center, University of Chile Clinical Hospital, Santiago. tmassardo@ns.hospital.uchile.cl
Insights
Adding ventricular function analysis to dipyridamole (DIP) stress tests did not significantly improve coronary artery disease (CAD) detection. While ejection fraction changes showed promise, overall diagnostic accuracy for CAD remained limited.
Area of Science:
- Nuclear Cardiology
- Cardiovascular Imaging
- Diagnostic Accuracy
Background:
- Coronary artery disease (CAD) diagnosis often relies on myocardial perfusion imaging.
- Assessing ventricular function alongside perfusion may enhance diagnostic capabilities.
Purpose of the Study:
- To evaluate the added value of ventricular function parameters, specifically ejection fraction (EF) and wall motion abnormalities (WMA), to dipyridamole (DIP)-stress myocardial perfusion imaging for CAD assessment.
Main Methods:
- A two-day Tc-99m sestamibi protocol was used in 52 patients with suspected CAD, including intravenous DIP with isometric handgrip exercise and rest injections.
- ECG-gated first-pass radionuclide ventriculography and planar perfusion images were acquired.
- Ventricular function was assessed by ejection fraction (EF) and wall motion abnormalities (WMA) during rest and DIP stress.
Main Results:
- Perfusion imaging alone showed 85% sensitivity and 91.7% specificity for CAD.
- CAD patients exhibited a significant decrease in EF with DIP stress (p=0.0015), more pronounced in those with perfusion defects (p=0.0001).
- Adding EF drop (> or = 5%) or WMA to perfusion imaging improved sensitivity (92.5% and 90%, respectively) but decreased specificity (75% and 58.3%, respectively).
Conclusions:
- First-pass ventricular function parameters derived from DIP-isometric exercise stress, when combined with perfusion imaging, do not significantly enhance the diagnostic assessment of coronary artery disease.
- While changes in ejection fraction and wall motion show potential, their impact on specificity limits their utility in routine CAD evaluation.
Abstract:
The main goal of this work was to know the value of ventricular function in addition to perfusion Tc-99m sestamibi images in the assessment of coronary artery disease (CAD) when using dipyridamole (DIP) associated to isometric exercise. We analyzed 52 patients with suspected CAD; 40 of them had coronary lesions > or = 50% and 12 patients without CAD, conforming study and control groups, respectively. Twenty-eight patients had prior myocardial infarction. A two-day sestamibi protocol was employed with i.v. DIP-handgrip and rest injections, acquiring ECG-gated first pass and planar perfusion images. Sensitivity for perfusion images was 85% and specificity was 91.7%. There was no change between rest and DIP ejection fraction (EF) in controls. CAD patients presented a significant EF decrease with DIP (p: 0.0015). Patients with ischemia in perfusion images had larger EF decrease (p: 0.0001). For the analysis, an EF drop > or = 5% and any wall motion abnormality (WMA) were considered as having an abnormal response to DIP. CAD sensitivity improved significantly to 92.5% when adding EF drop and to 90% when adding WMA parameters, but specificity decreased to 75% with EF drop, and to 58.3% with WMA. In conclusion, first pass parameters from DIP-isometric exercise in addition to perfusion images are not a significant help in the assessment of CAD.