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Left ventricular perfusion and function using gated-SPECT scintigraphy in patients with previous myocardial infarction
Journal of Nuclear Cardiology Volume 6, Number 1, Part 2
Abstracts Tuesday morning, April 20, 1999
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LEFT VENTRICULAR PERFUSION AND FUNCTION USING GATED-SPECT SCINTIGRAPHY IN PATIENTS WITH PREVIOUS MYOCARDIAL INFARCTION. Marco Ma77anti, Erick Alexanderson*, Diana Victoria*, Patrizia Lemus* and Augusto Purcaro. Ospedale Cardiologico "G.M.Lancisi", Ancona, Italy and "lstituto Naeional de Cardiologia "lgnacio Chavez",Mexico City
R E G I C N A L W A L L M O T I C N Q C R R E L A T E D W I T H GI..CBAL L V FUNCTION BETTER THAN WALL THICKENING: ASSESSMENT BY QUANTITATIVE GATED SPECT I Adachi, K Morita, M Konno, MB Irnran, N Kubo, T Mochizuki, N Tamaki.
Gated 99mTc-sestamibi single-photon emission computed tomography (g-SPECT) have demonstrated to be accurate for evaluation of post-stress viable ischemic myocardium. Aim of the study is to detect if post-stress left ventricular ejection fraction (LVEF) can add informafions over perfusion alone in patients (pts) with previous myocardial infarction (MI). Nethade. Rest TI-201 (r-TI), (2.5 to 3.5 mCi) and peak treadmgl exercise 99mTc-sestamibi (s-Tc), (20 to 30 mCi) were injected in 94 pts with history of previous M[ (dated 21 - 48 days before, mean 35.4). The tocation of MI was anterior in 39 pts, inferior in 45 pts and anterior + inferior in 10 pts. All g-SPECT studies were acquired using a single head camera after 5-10 minutes and 30-45 minutes r-TI and s-Tc injection respectively. Left ventricular volumes and LVEF were generated by an automated 3-dimensional validated software. Summes severity score (SSS) and summed reversibility score (SRS) were Calculated using a 4-point scale (g=normal, 3=absent uptake). We defined high SSS if 2 8, high SRS if _>50% of SSS, low SRS if < 50% of SS8, low LVEF if _<0.40 and normal LVEE if > 0.40. Clinical follow up (73-96 days, mean 78.2) of pts was studied to check soft events (angina, symptomatic left ventricular dysfunction and complex arrhythmJas). ~esults. Group A Group B Group C (21 pts) (18 pts) (20 pts) SSS 9.0 + 1.4 9.3 + 1.6 9.9 _+1.8 SRS ~ 5.2_+1.3 3.34-0.7 4.2_+1.1 post-stress LVEF 0.394-0.13 0.594-0.12 [ 0.37_+0.14 Soft Events 33% (7 pts) 5% (1 pts)* I 45% (9 pts) (*p=&O05 vs GroupA and GroupC) Fifty-nine pts (63%) had high SSS. Of interest we identified 3 groups: pts with high SSS, high SRS and low LVEF(Group A), pts with high SSS, low SRS and normal LVEF (Group8) and pts with high SSS, low SRS and low LVEF (Group C). Group A with multiple reversible perfusion defects and left ventricular systolic dysfunction is consistent with large amount of ischemia still present at time of acquisition. Group B presents both muttiple fixed perfusion defects with normal left ventricular systolic function which instead was abnormal in Group C. At the follow up Group A and Group C presented higher percentage of soft events than Group B (p=O.O05). Conclusion. In pts early after AMI the g-SPECT myocardial scintigraphy allows the identification of subgroups at high risk of soft cardiac events. LVEF add important informations over perfusion identifying the viable myocardium which needs to he revascularized.
Hokkaido University School of Medicine, Sapporo, Japan. Quantitative myocardial gated SPECT (QGS) has been validated for accurate measurement of LVEF. However, segmental wall motion (WM) or thickening (WT) processed by QGS werenot fully analyzed in relation to LVEF. Weevaluated the relationship between LVEF and segmental WM or WT score. Myocardial gated SPECT was performed in 44 patients with coronary artery disease 1 hr following administration of 600MBq of Tc-99m MIBI at rest. 3D surface images, splash images and global LVEF were automatically processed by QGS software. LV were divided into 5 segments; anterior (Ant), septal (Sep), apical (Ap), inferior (Inf) and lateral wall (Lat). WM by cine 3D surface images and w r by cine splash images were scored visually as 5 point grading system (0 as normal to 4 as akinesis or no wall thickening) by six observers to calculate mean regional WM and WT scores. The individual and summed scores were compared with global EF by linear regression. The correlation coefficients were: Seg Ant Sep Ap lnf Lat Sum WM 0.61 0.60 0.66 0.71 0.61 0.83 WT 0.42 0.44 0.46 0.59 0.44 0.74 Significant correlation was observed between global LVEF and individual as well as summed regional functions. LVEF correlated better with WM than WT. Among regional parameters, wall motion in inferior and apical regions contributes stronger impact on global LV function.
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LOW-DOSE DOBUTAM1NE GATED SPECT; IMPROVEMENT OF REGIONAL FUNCTION 1N ACCORDANCE WITH GLOBAL CHANGES FOR VIABILITY ASSESSMENT D.S. Lee, S.T. Lira, G.J. Cheon, M.M. Lee, J.-K. Chung, M.C. Lee. Seoul National University, Seoul, Korea
TC-99M SESTAMIBI GATED SPECT IN SUBENDOCARDIAL INFARCTION AND MYOCARDIAL STUNNING. BB Chin, D Kraitchman, I Oznur. Johns Hopkins Medical Institutions, Baltimore, MD, USA The purpose of this study is characterize myocardial function and perfusion defect severity in canine models of stunning and subendocardial infarction (sMI) at rest and after dobutarnine. Eight dogs were studied. Group A were controls. Group B sMIs were made by 90 min LAD cath occlusion and reflow. Group C stunning was produced by partial LAD occlusion and reflow. Sestamibi (0.75-1.0 mCi/kg) injections were at rest after reflow. SPECT was acquired on a 3-detector system (8 bins/beat). Bullseye plots quantified severity. Systolic wall thickening index (SWI)=[end systole-end diastole]/end systole* 100. Wall motion was validated by MRI with fast SPGR, ECG-gated tagging. ]q~C delineated viability. Extent of wall motion abnormalities was greater than TTC infarct size. In group C (no infarct by TTC), distal anterior hypokinesis at rest markedly improved with dobutamine (5gg/kg/min). Dog anterior SWI defect baseline dobutamine change A1 none 18% 37% lt% A2 none 20% 29% 9% A3 none 23% 37% i4% B1 mild-mod 15% 28% 13% B2 mild-mod 4% 20% 16% B3 mild meal -2% 2% 4% C1 mild~mod 3% 34% 31% C2 mild-meal -6% 30% 36% Small subendocardial infarctions and stunning produced mildmoderate defects in ungated and end-diastolic images. Preliminary results show the magnitude of improvement in SWI was greater for stunned myocardium compared to subendocardial infarction.
We examined whether regional changes of dysfunctional myocardium were represented by global changes during dobutamine infusion in gated myocardial SPECT. Lowdose dobutamine (5 },tg/kg/min) myocardial SPECT was performed after rest T1-201/gated Tc-99m MIBI dipyridamole stress SPECT in 22 patients with coronary artery disease. Endsystolic elastance (Emax), enddiastolic volume and blood pressure were measured using Cedars QGS and arterial tonometry. Perfusion (0 to 3: normal to defect), wall motion (0 to 4: normal to dyskinesia) and wall thickening (0 to 3: normal to absent) were graded visually. Changes of global parameters were used to predict improvement of regional wall thickening by discriminant analysis. Among 374 segments, 87 were dysfunctional with persistent or partially reversible perfusion defect. Ejection fraction (EF) and Emax improved significantly in the patients having improved regional function (group I) and having not (group II). Enddiastolic and endsystolic volumes decreased and blood pressure increased in group I but not in group II. EF was the only discriminant parameter to predict improvement of wall thickening during dobutamine infusion. We concluded that improvement of walt thickening of dysfunctional myocardium was represented in the increase of EF during dubutamine infusion.
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Abstracts Tuesday morning, April 20, 1999
$45
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LEFT VENTRICULAR PERFUSION AND FUNCTION USING GATED-SPECT SCINTIGRAPHY IN PATIENTS WITH PREVIOUS MYOCARDIAL INFARCTION. Marco Ma77anti, Erick Alexanderson*, Diana Victoria*, Patrizia Lemus* and Augusto Purcaro. Ospedale Cardiologico "G.M.Lancisi", Ancona, Italy and "lstituto Naeional de Cardiologia "lgnacio Chavez",Mexico City
R E G I C N A L W A L L M O T I C N Q C R R E L A T E D W I T H GI..CBAL L V FUNCTION BETTER THAN WALL THICKENING: ASSESSMENT BY QUANTITATIVE GATED SPECT I Adachi, K Morita, M Konno, MB Irnran, N Kubo, T Mochizuki, N Tamaki.
Gated 99mTc-sestamibi single-photon emission computed tomography (g-SPECT) have demonstrated to be accurate for evaluation of post-stress viable ischemic myocardium. Aim of the study is to detect if post-stress left ventricular ejection fraction (LVEF) can add informafions over perfusion alone in patients (pts) with previous myocardial infarction (MI). Nethade. Rest TI-201 (r-TI), (2.5 to 3.5 mCi) and peak treadmgl exercise 99mTc-sestamibi (s-Tc), (20 to 30 mCi) were injected in 94 pts with history of previous M[ (dated 21 - 48 days before, mean 35.4). The tocation of MI was anterior in 39 pts, inferior in 45 pts and anterior + inferior in 10 pts. All g-SPECT studies were acquired using a single head camera after 5-10 minutes and 30-45 minutes r-TI and s-Tc injection respectively. Left ventricular volumes and LVEF were generated by an automated 3-dimensional validated software. Summes severity score (SSS) and summed reversibility score (SRS) were Calculated using a 4-point scale (g=normal, 3=absent uptake). We defined high SSS if 2 8, high SRS if _>50% of SSS, low SRS if < 50% of SS8, low LVEF if _<0.40 and normal LVEE if > 0.40. Clinical follow up (73-96 days, mean 78.2) of pts was studied to check soft events (angina, symptomatic left ventricular dysfunction and complex arrhythmJas). ~esults. Group A Group B Group C (21 pts) (18 pts) (20 pts) SSS 9.0 + 1.4 9.3 + 1.6 9.9 _+1.8 SRS ~ 5.2_+1.3 3.34-0.7 4.2_+1.1 post-stress LVEF 0.394-0.13 0.594-0.12 [ 0.37_+0.14 Soft Events 33% (7 pts) 5% (1 pts)* I 45% (9 pts) (*p=&O05 vs GroupA and GroupC) Fifty-nine pts (63%) had high SSS. Of interest we identified 3 groups: pts with high SSS, high SRS and low LVEF(Group A), pts with high SSS, low SRS and normal LVEF (Group8) and pts with high SSS, low SRS and low LVEF (Group C). Group A with multiple reversible perfusion defects and left ventricular systolic dysfunction is consistent with large amount of ischemia still present at time of acquisition. Group B presents both muttiple fixed perfusion defects with normal left ventricular systolic function which instead was abnormal in Group C. At the follow up Group A and Group C presented higher percentage of soft events than Group B (p=O.O05). Conclusion. In pts early after AMI the g-SPECT myocardial scintigraphy allows the identification of subgroups at high risk of soft cardiac events. LVEF add important informations over perfusion identifying the viable myocardium which needs to he revascularized.
Hokkaido University School of Medicine, Sapporo, Japan. Quantitative myocardial gated SPECT (QGS) has been validated for accurate measurement of LVEF. However, segmental wall motion (WM) or thickening (WT) processed by QGS werenot fully analyzed in relation to LVEF. Weevaluated the relationship between LVEF and segmental WM or WT score. Myocardial gated SPECT was performed in 44 patients with coronary artery disease 1 hr following administration of 600MBq of Tc-99m MIBI at rest. 3D surface images, splash images and global LVEF were automatically processed by QGS software. LV were divided into 5 segments; anterior (Ant), septal (Sep), apical (Ap), inferior (Inf) and lateral wall (Lat). WM by cine 3D surface images and w r by cine splash images were scored visually as 5 point grading system (0 as normal to 4 as akinesis or no wall thickening) by six observers to calculate mean regional WM and WT scores. The individual and summed scores were compared with global EF by linear regression. The correlation coefficients were: Seg Ant Sep Ap lnf Lat Sum WM 0.61 0.60 0.66 0.71 0.61 0.83 WT 0.42 0.44 0.46 0.59 0.44 0.74 Significant correlation was observed between global LVEF and individual as well as summed regional functions. LVEF correlated better with WM than WT. Among regional parameters, wall motion in inferior and apical regions contributes stronger impact on global LV function.
T U E S D A Y A M
23.30
23.32
LOW-DOSE DOBUTAM1NE GATED SPECT; IMPROVEMENT OF REGIONAL FUNCTION 1N ACCORDANCE WITH GLOBAL CHANGES FOR VIABILITY ASSESSMENT D.S. Lee, S.T. Lira, G.J. Cheon, M.M. Lee, J.-K. Chung, M.C. Lee. Seoul National University, Seoul, Korea
TC-99M SESTAMIBI GATED SPECT IN SUBENDOCARDIAL INFARCTION AND MYOCARDIAL STUNNING. BB Chin, D Kraitchman, I Oznur. Johns Hopkins Medical Institutions, Baltimore, MD, USA The purpose of this study is characterize myocardial function and perfusion defect severity in canine models of stunning and subendocardial infarction (sMI) at rest and after dobutarnine. Eight dogs were studied. Group A were controls. Group B sMIs were made by 90 min LAD cath occlusion and reflow. Group C stunning was produced by partial LAD occlusion and reflow. Sestamibi (0.75-1.0 mCi/kg) injections were at rest after reflow. SPECT was acquired on a 3-detector system (8 bins/beat). Bullseye plots quantified severity. Systolic wall thickening index (SWI)=[end systole-end diastole]/end systole* 100. Wall motion was validated by MRI with fast SPGR, ECG-gated tagging. ]q~C delineated viability. Extent of wall motion abnormalities was greater than TTC infarct size. In group C (no infarct by TTC), distal anterior hypokinesis at rest markedly improved with dobutamine (5gg/kg/min). Dog anterior SWI defect baseline dobutamine change A1 none 18% 37% lt% A2 none 20% 29% 9% A3 none 23% 37% i4% B1 mild-mod 15% 28% 13% B2 mild-mod 4% 20% 16% B3 mild meal -2% 2% 4% C1 mild~mod 3% 34% 31% C2 mild-meal -6% 30% 36% Small subendocardial infarctions and stunning produced mildmoderate defects in ungated and end-diastolic images. Preliminary results show the magnitude of improvement in SWI was greater for stunned myocardium compared to subendocardial infarction.
We examined whether regional changes of dysfunctional myocardium were represented by global changes during dobutamine infusion in gated myocardial SPECT. Lowdose dobutamine (5 },tg/kg/min) myocardial SPECT was performed after rest T1-201/gated Tc-99m MIBI dipyridamole stress SPECT in 22 patients with coronary artery disease. Endsystolic elastance (Emax), enddiastolic volume and blood pressure were measured using Cedars QGS and arterial tonometry. Perfusion (0 to 3: normal to defect), wall motion (0 to 4: normal to dyskinesia) and wall thickening (0 to 3: normal to absent) were graded visually. Changes of global parameters were used to predict improvement of regional wall thickening by discriminant analysis. Among 374 segments, 87 were dysfunctional with persistent or partially reversible perfusion defect. Ejection fraction (EF) and Emax improved significantly in the patients having improved regional function (group I) and having not (group II). Enddiastolic and endsystolic volumes decreased and blood pressure increased in group I but not in group II. EF was the only discriminant parameter to predict improvement of wall thickening during dobutamine infusion. We concluded that improvement of walt thickening of dysfunctional myocardium was represented in the increase of EF during dubutamine infusion.
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