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Quantitative assessment of the severity of perfusion defects in SPECT studies of the heart
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Abstracts Tuesday afternoon, April 25, 1995
March/April 1995, Part 2
P14-301
P14-303
QUANTITATIVE ASSESSMENT OF THE SEVERITY OF PERFUSION DEFECTS IN SPECT STUDIES OF THE HEART
REVERSE REDISTRIBUTION IN RESTING THALLIUM-201 MYOCARDIAL SCINTIGRAPHY IN CHRONIC CORONARY ARTERY DISEASE: AN INDEX OF MYOCARDIAL VIABILITY.
Carlo Caiati, Michael O'Connor, Timothy Christian, Raymond Gibbons, Fondazione Clinica del Lavoro, Cassano Murge, Bari, Italy, and Mayo Clinic, Rochester, MN.
T U E S D A u
JOURNAL OF NUCLEAR CARDIOLOGY
In Tc-99m sestamibi SPECT, the nadir in short axis circumferential profiles is significantly associated with angiographic collateral grade. This study examined the effects of infarct size, scatter and radioisotope on the relationship between the nadir and actual activity in the infarct zone in a cardiac phantom. SPECT images of the phantom containing 0,20,35 and 50% defects with severity 0-90%, were acquired for T1-201 and Tc-99m with and without scatter correction. Three indices - the nadir, nadir in basal slice and profile area below a fixed threshold (defect area) showed an excellent correlation with known defect activity (r > 0.95). There was no significant difference between nadir and basal nadir indices. After scatter correction, the slope of the regression line for the nadir index with Tc-99m, increased from 0.73 to 0.81 and the average absolute error in estimating true defect activity decreased from 6.7_+4.1% to 3.2+2.8%. For TI-20I the slopes varied between 0.53-0.62 with absolute errors of 12-18%. Scatter correction did not significantly alter these results. Isotope and scatter correction had no significant effect on results for defect area. Defect activity and size, scatter correction and isotope were all significantly independent determinants of the 3 indices, and models incorporating these factors accounted for 96-99% of the variability in the 3 indices. These results provide the technical basis for the use of these indices for the noninvasive measurement of residual blood flow in the infarct zone.
Leonardo Pace, Alberto Cuocolo, Paolo Marzullo, Emanuele Nicolai, Alessia Gimelli, Nicola De Luca, Bruno Ricciardelli, Marco Salvatore. Universit& "Federico I1" and Istituto Nazionale Tumori, Napoli and Istituto di Fisiologia Clinica, CNR, Pisa, Italy. Nineteen patients (17 men and 2 women, mean age 53~8 yrs) with coronary artery disease underwent rest-redistribution thallium-201 (T~) and rest tachnetium-99m methoxy isobuty| isonitrile (MIBI) scintigraphy before coronary revascularization (CR). Regional TI and MIBI uptake were quantitatively analyzed. Echocard~ographic left ventricular wall motion (WM) was assessed before and after CR with a 3-point scale (1=normal, 2=hypokinetic, 3=akinetic/dyskinetic). Two patterns of reverse redistribution (RR): were identified: RR-A (normal TI uptake in rest and abnormal in redistribution images), and RR-B (abnormal TI uptake in rest and significant decrease in redistribution images). Of the 247 segments analyzed, 85 were normal, 37 reversible defects, 83 fixed defects, and 42 RR (19 RR-A and 23 RR-B). RR-A segments differed from RR-B in WM score (1~4_+0.7vs 2.0+1.0, p<0.05) and in MIBI uptake (75+14% vs 60_+13%, p<0.001). Electrocardiographic Q waves were present in 26% of RR-A segments and in 57% of RR-B segments (p<0.05). After CR, all dyssynergic segments with RR-A showed improved WM, while only 40% of dyssynergic segments with RR-B had such an improvement (p<0.05 vs RR-A). Our results suggest that dyssynergic segments with RR-A should be considered viable.
P M A P R I L
P 14-302
P 14-304
Tc-99m MIBI CARDIAC TOMOGRAPHY ASSOCIATED WITH ADENOSINE CONTROLLED CORONARY VASODILATION IN PATIENTS WITH CORONARY ARTERY DISEASE.
COMPARATIVE DATA ANALYSIS OF EXERCISE ECG AND MYOCARDIAL PERFUSION S C I N T I G R A P H Y IN P A T I E N T S W I T H A N G I N A A N D SILENT I S C H A E M I A O. Partos, M. Gydrgy, M. IstvAnffy Dept. o f Nuclear Cardiology, Hungarian Inst. o f Cardiology, Budapest, Hungary
Emanuele Nicolai, Alberto Cuocolo, Leonardo Pace, Andrea Soricelli, Antonio Nappi, Fiorenzo Squame, Pasquale Sullo, Stefania Cardei, Marco Salvatore. Universit& "Federico ll" and Istituto Nazionale dei Tumori, Napoli, Italy. The aim of this study was to investigate the usefulness of adenosine Tc-ggm MIBI tomography in the diagnosis and localization of coronary artery disease (CAD). We studied 57 patients (52 men, mean age 52+10 yrs) with proven CAD (.~50% coronary stenosis): 49 with previous myocardial infarction (MI) and 8 without MI. All patients underwent Tc-99m MIBI tomography after administration of adenosine (140 gg/Kg iv for 6 mini. Adenosine induced a significant (p<0.01) increase of heart rate (90_+16 bpm at peak vs 71_+12 bpm at rest). Blood pressure was not different after adenosine compared to rest. Side effects occurred in 44% of the patients. However, all symptoms were mild and resolved spontaneously within 2 rain after discontinuing adenosine infusion. A total of 171 coronary territories were quantitatively analyzed. The overall sensitivity, specificity and predictive accuracy for detection of stenosed vessels were were 88%, 80% and 85%, respectively. Sensitivity, specificity and predictive accuracy for detection of stenosed vessels were 92%, 82% and 88% in patients without MI and 87%, 80% and 76% in those with previous Ml. In conclusion, adenosine Tc-99m MIBI cardiac tomography is safe and accurate in evaluating the presence and localization of CAD.
73 patients (pts.), (45 male, 28 female, mean age 55.5 years) have been studied with anamnestic chest pain. Myocardial ischaemia has been verified by sign and symptom limited exercise test (stress E C G - Bruce protocol) and by 2 0 l - T h a l l i u m myocardial perfusion Single Photon Emission C o m p u t e r T o m o g r a p h y (SPECT). Two groups were selected. Group "A", 27 pts. with exercise induced angina and G r o u p "SI", 46 silent ischaemic pts. with significant stress E C G - S T depression and/or reversible regional myocardial perfusion defect. There were not found significant differences between Group "A" and Group "SI" in age, anamnestic events (recent myocardial infarction, anginal pain), in exercise tolerance (maximal workload, double product) and in S P E C T score o f reversibility rate and extension o f hypoperfusion as well. Conclusion: similar underlying ischaemic pattern could be supposed in stress induced myocardial ischaemia with or without chest pain based on stress E C G and S P E C T data.
Abstracts Tuesday afternoon, April 25, 1995
March/April 1995, Part 2
P14-301
P14-303
QUANTITATIVE ASSESSMENT OF THE SEVERITY OF PERFUSION DEFECTS IN SPECT STUDIES OF THE HEART
REVERSE REDISTRIBUTION IN RESTING THALLIUM-201 MYOCARDIAL SCINTIGRAPHY IN CHRONIC CORONARY ARTERY DISEASE: AN INDEX OF MYOCARDIAL VIABILITY.
Carlo Caiati, Michael O'Connor, Timothy Christian, Raymond Gibbons, Fondazione Clinica del Lavoro, Cassano Murge, Bari, Italy, and Mayo Clinic, Rochester, MN.
T U E S D A u
JOURNAL OF NUCLEAR CARDIOLOGY
In Tc-99m sestamibi SPECT, the nadir in short axis circumferential profiles is significantly associated with angiographic collateral grade. This study examined the effects of infarct size, scatter and radioisotope on the relationship between the nadir and actual activity in the infarct zone in a cardiac phantom. SPECT images of the phantom containing 0,20,35 and 50% defects with severity 0-90%, were acquired for T1-201 and Tc-99m with and without scatter correction. Three indices - the nadir, nadir in basal slice and profile area below a fixed threshold (defect area) showed an excellent correlation with known defect activity (r > 0.95). There was no significant difference between nadir and basal nadir indices. After scatter correction, the slope of the regression line for the nadir index with Tc-99m, increased from 0.73 to 0.81 and the average absolute error in estimating true defect activity decreased from 6.7_+4.1% to 3.2+2.8%. For TI-20I the slopes varied between 0.53-0.62 with absolute errors of 12-18%. Scatter correction did not significantly alter these results. Isotope and scatter correction had no significant effect on results for defect area. Defect activity and size, scatter correction and isotope were all significantly independent determinants of the 3 indices, and models incorporating these factors accounted for 96-99% of the variability in the 3 indices. These results provide the technical basis for the use of these indices for the noninvasive measurement of residual blood flow in the infarct zone.
Leonardo Pace, Alberto Cuocolo, Paolo Marzullo, Emanuele Nicolai, Alessia Gimelli, Nicola De Luca, Bruno Ricciardelli, Marco Salvatore. Universit& "Federico I1" and Istituto Nazionale Tumori, Napoli and Istituto di Fisiologia Clinica, CNR, Pisa, Italy. Nineteen patients (17 men and 2 women, mean age 53~8 yrs) with coronary artery disease underwent rest-redistribution thallium-201 (T~) and rest tachnetium-99m methoxy isobuty| isonitrile (MIBI) scintigraphy before coronary revascularization (CR). Regional TI and MIBI uptake were quantitatively analyzed. Echocard~ographic left ventricular wall motion (WM) was assessed before and after CR with a 3-point scale (1=normal, 2=hypokinetic, 3=akinetic/dyskinetic). Two patterns of reverse redistribution (RR): were identified: RR-A (normal TI uptake in rest and abnormal in redistribution images), and RR-B (abnormal TI uptake in rest and significant decrease in redistribution images). Of the 247 segments analyzed, 85 were normal, 37 reversible defects, 83 fixed defects, and 42 RR (19 RR-A and 23 RR-B). RR-A segments differed from RR-B in WM score (1~4_+0.7vs 2.0+1.0, p<0.05) and in MIBI uptake (75+14% vs 60_+13%, p<0.001). Electrocardiographic Q waves were present in 26% of RR-A segments and in 57% of RR-B segments (p<0.05). After CR, all dyssynergic segments with RR-A showed improved WM, while only 40% of dyssynergic segments with RR-B had such an improvement (p<0.05 vs RR-A). Our results suggest that dyssynergic segments with RR-A should be considered viable.
P M A P R I L
P 14-302
P 14-304
Tc-99m MIBI CARDIAC TOMOGRAPHY ASSOCIATED WITH ADENOSINE CONTROLLED CORONARY VASODILATION IN PATIENTS WITH CORONARY ARTERY DISEASE.
COMPARATIVE DATA ANALYSIS OF EXERCISE ECG AND MYOCARDIAL PERFUSION S C I N T I G R A P H Y IN P A T I E N T S W I T H A N G I N A A N D SILENT I S C H A E M I A O. Partos, M. Gydrgy, M. IstvAnffy Dept. o f Nuclear Cardiology, Hungarian Inst. o f Cardiology, Budapest, Hungary
Emanuele Nicolai, Alberto Cuocolo, Leonardo Pace, Andrea Soricelli, Antonio Nappi, Fiorenzo Squame, Pasquale Sullo, Stefania Cardei, Marco Salvatore. Universit& "Federico ll" and Istituto Nazionale dei Tumori, Napoli, Italy. The aim of this study was to investigate the usefulness of adenosine Tc-ggm MIBI tomography in the diagnosis and localization of coronary artery disease (CAD). We studied 57 patients (52 men, mean age 52+10 yrs) with proven CAD (.~50% coronary stenosis): 49 with previous myocardial infarction (MI) and 8 without MI. All patients underwent Tc-99m MIBI tomography after administration of adenosine (140 gg/Kg iv for 6 mini. Adenosine induced a significant (p<0.01) increase of heart rate (90_+16 bpm at peak vs 71_+12 bpm at rest). Blood pressure was not different after adenosine compared to rest. Side effects occurred in 44% of the patients. However, all symptoms were mild and resolved spontaneously within 2 rain after discontinuing adenosine infusion. A total of 171 coronary territories were quantitatively analyzed. The overall sensitivity, specificity and predictive accuracy for detection of stenosed vessels were were 88%, 80% and 85%, respectively. Sensitivity, specificity and predictive accuracy for detection of stenosed vessels were 92%, 82% and 88% in patients without MI and 87%, 80% and 76% in those with previous Ml. In conclusion, adenosine Tc-99m MIBI cardiac tomography is safe and accurate in evaluating the presence and localization of CAD.
73 patients (pts.), (45 male, 28 female, mean age 55.5 years) have been studied with anamnestic chest pain. Myocardial ischaemia has been verified by sign and symptom limited exercise test (stress E C G - Bruce protocol) and by 2 0 l - T h a l l i u m myocardial perfusion Single Photon Emission C o m p u t e r T o m o g r a p h y (SPECT). Two groups were selected. Group "A", 27 pts. with exercise induced angina and G r o u p "SI", 46 silent ischaemic pts. with significant stress E C G - S T depression and/or reversible regional myocardial perfusion defect. There were not found significant differences between Group "A" and Group "SI" in age, anamnestic events (recent myocardial infarction, anginal pain), in exercise tolerance (maximal workload, double product) and in S P E C T score o f reversibility rate and extension o f hypoperfusion as well. Conclusion: similar underlying ischaemic pattern could be supposed in stress induced myocardial ischaemia with or without chest pain based on stress E C G and S P E C T data.