Related Experiment Videos
Enhanced detection of viable myocardium by technetium-99m-MIBI imaging after nitrate administration in chronic
S Maurea1, A Cuocolo, A Soricelli
1Nuclear Medicine Department, University Federico II, Naples, Italy.
Insights
Nitrate administration enhances myocardial viability detection using 99mTc-MIBI imaging in coronary artery disease (CAD) patients with left ventricular (LV) dysfunction. This improves assessment of severely hypoperfused, yet viable, heart muscle.
Area of Science:
- Nuclear Cardiology
- Cardiovascular Imaging
- Myocardial Perfusion Imaging
Background:
- Coronary artery disease (CAD) often leads to chronic left ventricular (LV) dysfunction.
- Assessing myocardial viability is crucial for guiding revascularization strategies in CAD patients.
- Technetium-99m methoxyisobutyl isonitrile (99mTc-MIBI) tomography is used to evaluate myocardial perfusion.
Purpose of the Study:
- To determine if nitrate administration improves the accuracy of 99mTc-MIBI tomography in detecting viable myocardium in patients with CAD.
- To evaluate the impact of nitroglycerine on the sensitivity of 99mTc-MIBI imaging for identifying viable heart muscle.
Main Methods:
- Thirty-one patients with confirmed CAD and LV dysfunction underwent two 99mTc-MIBI scans: one at rest and one after oral nitroglycerine administration.
- All patients also had rest-redistribution 201Thallium (201Tl) imaging within one week.
- Eight patients had echocardiography before and after coronary revascularization.
Main Results:
- Nitroglycerine administration increased the detection of viable myocardium in segments with severely reduced 99mTc-MIBI uptake, with 27% showing increased uptake and viability on 201Tl scans.
- Segments with severely reduced 99mTc-MIBI uptake and no change after nitroglycerine were predominantly nonviable (81% on 201Tl).
- In patients who underwent revascularization, reversible 99mTc-MIBI defects correlated with functional recovery (87%), while irreversible defects did not (89%).
Conclusions:
- Nitrate administration significantly improves the detection of viable myocardium in patients with chronic ischemic LV dysfunction using 99mTc-MIBI imaging.
- This enhancement aids in identifying severely hypoperfused but still viable myocardial segments.
- The findings suggest that nitroglycerine can augment the diagnostic utility of 99mTc-MIBI for risk stratification in CAD.
Unlabelled:
The aim of this study was to assess whether nitrate administration improves the imaging capabilities of 99mTc-MIBI tomography in detecting viable myocardium in coronary artery disease (CAD).
Methods:
Thirty-one patients with angiographically proven CAD and chronic LV dysfunction (ejection fraction 39% +/- 9%) underwent two 99mTc-MIBI studies on separate days: one under rest conditions and the other after nitroglycerine (0.005 mg/kg per os) administration. Within 1 wk, all patients also underwent rest-redistribution 201Tl imaging. Eight patients were also studied by echocardiography before and 5 +/- 3 mo after coronary revascularization.
Results:
On resting 99mTc-MIBI images, 302 segments had normal uptake, 183 segments had moderately reduced uptake and 197 had severely reduced uptake. Of the segments with severely reduced uptake, 54 (27%) had increased uptake after nitroglycerine and were viable on 201Tl images. Of the 143 (73%) segments with severely reduced 99mTc-MIBI uptake and no change after nitroglycerine, 81% were nonviable on 201Tl images. In the eight patients studied before and after revascularization, 87% of segments with reversible 99mTc-MIBI defects and abnormal LV function demonstrated functional recovery after revascularization, whereas 89% of segments with irreversible 99mTc-MIBI defects did not.
Conclusion:
In patients with chronic ischemic LV dysfunction, nitrate administration improved the detection of severely hypoperfused but still viable myocardium on 99mTc-MIBI images.