Post-stress Left Ventricular Ejection Fraction Research Articles

Valor pronóstico de la gammagrafía de perfusión miocárdica con 201Tl normal en el postinfarto agudo de miocardio

Objective The purpose of this work has been to determine the prognostic value of normal thallium-201 myocardial perfusion scintigraphy (MPS) in patients who had suffered myocardial infarction in the three months prior to the examination. Material and methods A stress test followed by 201Tl Gated SPECT was performed. A follow-up was made of 63 patients with normal perfusion scintigraphy. According to the MPS results, the patients were divided into 2 groups. Group I (n = 63; 57% males, age 65 ± 12), patients with normal MPS, and group II (n = 60; 81% males, age 64 ± 10), patients with abnormal MPS. The appearance of a new infarction or cardiac death occurring during this period (63 ± 3 months) was analyzed. The appearance of events was related with the cardiovascular risk factors, perfusion study and ventricular function. Results Five events occurred in group I in 4 patients: 3 new infarctions and 2 cardiac deaths. In group II, there were 18 events in 14 patients: 8 new infarctions and 10 cardiac deaths (p < 0,0001). The events were related with age, time from MPS, diabetes, size of perfusion defect and post stress ventricular ejection fraction. Mean survival en group I was 108 months (103–112) and in group II 97 (88–107) (p = 0,01). Conclusion Patients with normal MPS had fewer major events than patients with abnormal MPS. The size of MPS has been related with the appearance of events. A depressed post-stress left ventricular ejection fraction has a poor prognosis.

Prognostic value of normal myocardial perfusion scintigraphy with 201Tl in post-acute myocardial infarction

Objective The purpose of this work has been to determine the prognostic value of normal thallium-201 myocardial perfusion scintigraphy (MPS) in patients who had suffered myocardial infarction in the three months prior to the examination. Material and methods A stress test followed by 201Tl Gated SPECT was performed. A follow-up was made of 63 patients with normal perfusion scintigraphy. According to the MPS results, the patients were divided into 2 groups. Group I (n = 63; 57% males, age 65 ± 12), patients with normal MPS, and group II (n = 60; 81% males, age 64±10), patients with abnormal MPS. The appearance of a new infarction or cardiac death occurring during this period (63±3 months) was analyzed. The appearance of events was related with the cardiovascular risk factors, perfusion study and ventricular function. Results Five events occurred in group I in 4 patients: 3 new infarctions and 2 cardiac deaths. In group II, there were 18 events in 14 patients: 8 new infarctions and 10 cardiac deaths (p<0.0001). The events were related with age, time from MPS, diabetes, size of perfusion defect and post stress ventricular ejection fraction. Mean survival en group I was 108 months (103-112) and in group II 97 (88-107) (p=0.01). Conclusion Patients with normal MPS had fewer major events than patients with abnormal MPS. The size of MPS has been related with the appearance of events. A depressed post-stress left ventricular ejection fraction has a poor prognosis.

Effect of imaging time on post stress left ventricular ejection fraction and volume measures by gated myocardial perfusion single photon emission computed tomography

Objectives: Post-stress left ventricular ejection fraction (LVEF) and LV volumes have incremental value in predicting cardiac death (CD) in patients with coronary artery disease. In this study, we aimed to investigate the effect of imaging time after exercise on post-stress LVEF, end-diastolic volume (EDV) and end-systolic volume (ESV) calculated by cardiac quantification software program called Quantitative Gated SPECT (QGS-Cedars-Sinai). Materials and methods: This study was consisted of 36 patient referred to Nuclear Medicine Department from Cardiology Clinics because of chest pain in lElazig Research and Training Hospital\' in 2008-2009. In all patients, ECG Gated (8-bin frame mode) myocardial perfusion SPECT scintigraphy was performed 20 and 40 min later following 99mTc-Mibi injection during exercise. By means of the cardiac quantification software program called Quantitative Gated SPECT (QGS-Cedars-Sinai); LVEF, EDV and ESV were calculated. LVEF, EDV and ESV values obtained from initial and second acquisition were compared statistically. Results: There was no statistically significant difference between post-stress LVEF, EDV and ESV measures of initial and second acquisition (p>0.05). Conclusion: Left ventricular functional parameters after exercise are important for assess prognosis in patients with CAD. Post-stress LVEF, EDV and ESV measured on gated myocardial perfusion SPECT images within 20-40 min after completion of exercise give reproducible information.

Improved Near-Term Coronary Artery Disease Risk Classification With Gated Stress Myocardial Perfusion SPECT

We compared analytical approaches to estimate the added value of myocardial perfusion single-photon emission computed tomography (MPS) variables in estimating coronary artery disease (CAD) outcomes. Stress MPS markers of regional ischemia are strong estimators of prognosis. Evidence published to date has not compared analytical methods to establish the added value of stress MPS and to define a clinically meaningful approach to detect improve classification of risk. A total of 4,575 patients were consecutively and prospectively enrolled in the Myoview Prognosis Registry. Multivariable Cox proportional hazards model were employed to estimate CAD death or myocardial infarction (MI). Risk reclassification methods were also calculated. In risk-adjusted models (including age, sex, presenting symptoms, stress type, CAD history, and risk factors), stress MPS ischemia, rest and post-stress left ventricular ejection fraction (LVEF) (all p < 0.0001) were all significant estimators of CAD death or MI. In this multivariable model, 34% of the model chi-square was contributed by MPS ischemia. In receiver-operating characteristic curve analysis, the area under the curve increased from 0.61 to 0.66 when rest and post-stress LVEF were combined with pre-test CAD likelihood (p < 0.0001), increasing to 0.69 for MPS ischemia (p < 0.0001). The net reclassification improvement (NRI) by adding the Duke Treadmill Score (DTS) to a model including pre-test CAD likelihood was 0.112. The cost per NRI was $57 for the exercise test as compared with an office visit for risk stratification purposes. Further, the NRI by adding MPS ischemia to a model with the DTS and pre-test CAD likelihood was 0.358. The cost per NRI was $615 for the stress MPS as compared with an exercise test. Stress-induced ischemia is independently predictive of near-term CAD outcomes. Analytical approaches that establish the reclassification of events provide a unique approach and may serve as a quality imaging metric for estimation of improved health outcomes for stress MPS as well as for comparison to other imaging modalities.

Assessment of poststress left ventricular ejection fraction by gated SPECT: comparison with equilibrium radionuclide angiocardiography

We compared left ventricular (LV) ejection fraction obtained by gated SPECT with that obtained by equilibrium radionuclide angiocardiography in a large cohort of patients. Within 1 week, 514 subjects with suspected or known coronary artery disease underwent same-day stress-rest (99m)Tc-sestamibi gated SPECT and radionuclide angiocardiography. For both studies, data were acquired 30 min after completion of exercise and after 3 h rest. In the overall study population, a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.82, p<0.0001) and after stress (r=0.83, p<0.0001). In Bland-Altman analysis, the mean differences in ejection fraction (radionuclide angiocardiography minus gated SPECT) were -0.6% at rest and 1.7% after stress. In subjects with normal perfusion (n=362), a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.72, p<0.0001) and after stress (r=0.70, p<0.0001) and the mean differences in ejection fraction were -0.9% at rest and 1.4% after stress. Also in patients with abnormal perfusion (n=152), a good correlation between the two techniques was observed both at rest (r=0.89, p<0.0001) and after stress (r=0.90, p<0.0001) and the mean differences in ejection fraction were 0.1% at rest and 2.5% after stress. In a large study population, a good agreement was observed in the evaluation of LV ejection fraction between gated SPECT and radionuclide angiocardiography. However, in patients with perfusion abnormalities, a slight underestimation in poststress LV ejection fraction was observed using gated SPECT as compared to equilibrium radionuclide angiocardiography.

Reduced Heart Rate Response to Dipyridamole as a Marker of Left Ventricular Dysfunction in Diabetic Patients Undergoing Myocardial Perfusion Scintigraphy

This study sought to find among clinical, hemodynamic and left ventricular perfusion and function data obtained from myocardial perfusion scintigraphy (MPS), those associated with a reduced heart rate (HR) response to dipyridamole in diabetic patients. This phenomenon, although previously described as a marker of autonomic dysfunction in patients with diabetes, has not been fully elucidated. One hundred two consecutive diabetic patients undergoing dual-isotope (rest Tl-201/dipyridamole stress Tc-99m tetrofosmin) MPS were prospectively enrolled. A reduced HR response to dipyridamole was considered present if the ratio between maximal HR after dipyridamole infusion and rest HR was <or=1.20. MPS images were interpreted semiquantitatively, and perfusion scores were calculated. Left ventricular ejection fraction (LVEF) was automatically obtained. A logistic regression analysis was used to find variables independently associated with a reduced HR response to dipyridamole. A reduced HR response to dipyridamole was found in 46.1% of the patients and was associated with the presence of chronic renal failure (chi2 = 6.4), with high baseline HR (chi2 = 4.7) and low poststress LVEF (chi2 = 10.6). Attenuation of the HR response to dipyridamole was frequent and was strongly associated with reduced LVEF. Autonomic dysfunction may be reflected in the higher baseline HR but should not be considered the sole mechanism accounting for the reduction in HR response to dipyridamole in patients with diabetes.

Left Ventricular Dysfunction Secondary to Ischemia in Women with Angina and Normal Coronary Angiograms

Microvascular disease is proposed as a cause of segmental myocardial blood flow abnormalities and heterogeneous myocardial perfusion in cardiac syndrome X. To assess if myocardial ischemia can be evidenced through both perfusion abnormalities and poststress left ventricular ejection fraction (LVEF) reduction by gated single photon emission tomography (SPECT) myocardial scintigraphy in women with syndrome X in a similar way to those with epicardial coronary lesions. Three groups of postmenopausal women were studied: group I, 20 women with angina, perfusion defects, and normal coronary angiography; group II, 20 women with epicardial coronary lesions (> or =50% of coronary lumen reduction); group III, 15 volunteers without signs or symptoms of ischemia (control group). Each underwent technetium-99m ((99m)TC) methoxyisobutylisonitrile gated SPECT myocardial scintigraphy (protocol: exercise-stress-rest), brachial artery endothelial function measured by ultrasonography, and lipidogram. Groups I and III patients had a higher body mass index (BMI). There were more smokers in groups I and II. Very low density lipoprotein cholesterol (VLDL-C) and triglycerides were higher in group II patients. The brachial artery vasodilator responsiveness after 5 minutes of ischemia was similarly lower in patients of groups I and II compared with those of group III (3% vs. 6.5%, respectively; p = 0.03 group III vs. group I and group II). Mean DeltaLVEF (LVEF poststress minus LVEF at rest) was -3.86%, -2.90%, and 4.18% in groups I, II, and III, respectively (p = NS between I and II, p = 0.005 between II and III, and p = 0.003 between I and III). In 43% of group I patients and in 10 of 18 group III patients with perfusion defects, there was a poststress LVEF reduction >5%. Stress-induced ischemia is associated with poststress LVEF reduction as a probable manifestation of myocardial stunning in postmenopausal women with typical angina and normal coronary angiography.

Ischemia in women with angina and normal coronary angiograms

Coronary artery disease is frequent in postmenopausal women. Myocardial ischemia has been induced with stress testing, and a relationship between endothelial dysfunction and perfusion defects has been reported. To evaluate whether myocardial ischemia can be evidenced both by perfusion and function abnormalities using gated single-photon emission computed-tomography myocardial scintigraphy with technetium-labeled compounds in women with typical angina, normal coronary angiography, and endothelial dysfunction. Fifty-nine postmenopausal patients were studied. Each underwent technetium-99m methoxy-isobutyl-isonitrile myocardial scintigraphy (protocol: exercise stress-rest), brachial artery endothelial function measured by ultrasonography, lipidogram, and 24-h ambulatory ECG recording (Holter). Twenty-one patients (group I) showed perfusion defects in myocardial scintigraphy, whereas the other 38 patients (group II) did not. Group I patients exhibited endothelial dysfunction more frequently (57 vs. 29%) than those of group II. Among group I patients, 12 showed a reversible perfusion defect that, in 75% of the cases, was associated with poststress left ventricular ejection fraction reduction greater than 5% and a regional hypokinesis. Nine patients had fixed defects, which in 56% of the cases were associated with poststress left ventricular ejection fraction reduction greater than 5%. Left ventricular ejection fraction poststress minus left ventricular ejection fraction at rest was -5.2% in group I patients versus -1.8% in group II (P<0.001). Three patients in group I showed evidence of ischemia by Holter compared with four in group II. Stress-induced ischemia is associated with poststress left ventricular ejection fraction reduction in postmenopausal women with typical angina, normal coronary angiography, and a trend toward abnormal endothelial-mediated vasodilation.

Prognóstico em médio prazo da cintilografia de perfusão miocárdica de estresse na unidade de dor torácica

To evaluate the prognostic value of stress myocardial perfusion scintigraphy (MPS) applied to patients with suspected acute coronary syndrome (ACS). Retrospective study. Patients with suspected acute coronary syndrome (ACS) admitted into the chest pain unit (CPU) from December 2002 to April 2004, after exclusion of acute myocardial infarction (AMI) and high risk unstable angina they underwent stress MPS. Selected 301 patients, 65.3 +/- 12.5 years and 164 (54.5%) male gender. The test was performed 13 +/- 12 hours after admission. Myocardial ischemia (ISQ) was found in 142 patients (47.2%). Male gender (n=94, p=<0.0001), history of diabetes mellitus (n=31, p=0.033), past of AMI (n=52, p=<0.0001), past of surgical myocardial revascularization (n=46, p=<0.0001) and past of percutaneous revascularization (n=68, p=<0.0001) presented correlation with ISQ. The follow-up was 697.7 +/- 326.6 days. No MPS variable correlated with the occurrence of primary outcome. Abnormal scintigraphy (n=76, p < 0.0001), ISQ (n=73, p < 0.0001) and post-stress left ventricular ejection fraction below 45% (n=21, p=0.006) correlated with secondary outcome. The presence of ISQ was the major variable in the multivariate analysis for the prediction of secondary outcome (RR = 6.5; CI 95% = 0.009). Presence of ISQ was the major independent factor in prediction of adverse events for patients admitted into the CPU.

Angina with Normal Epicardial Coronary Arteries: Does Gender Imply any Difference in Ischemia Detection?

To evaluate if gender implies any difference in ischemia detection both by perfusion and function abnormalities using gatedSPECT myocardial scintigraphy in patients with typical angina, normal coronary angiography, and endothelial dysfunction, 31 women (Group I) and 20 men (Group II) were studied. Each underwent technetium-99m methoxy-isobutyl-isonitrile myocardial scintigraphy, brachial artery endothelial function measured by ultrasonography and lipidogram. Five female and eight male patients showed a reversible perfusion defect with post-stress left ventricular ejection fraction (LVEF) reduction greater than 5%, associated with endothelial dysfunction in three women and four men. There was no significant difference neither in presence of endothelial dysfunction, nor in LVEF post-stress minus LVEF at rest (ΔLVEF): -2.71% in women vs. -2.41% in men. In patients with typical angina, normal coronary angiography and abnormal SPECT myocardial scintigraphy (both by perfusion and poststress left ventricular ejection fraction reduction), gender does not account for differences in the detection of ischemia.

Overestimation of postischemic myocardial stunning on gated SPECT imaging: Correlation with echocardiography

Postischemic global and regional left ventricular (LV) dysfunction on stress-gated single photon emission computed tomography (SPECT) imaging is attributed widely to myocardial stunning. We sought to determine the specificity of gated SPECT for the detection of myocardial stunning after ischemic stress. Twenty-seven patients with an ischemic response to stress on dual-isotope exercise SPECT were enrolled prospectively. Transthoracic echocardiography was performed just before stress gated SPECT for assessment of regional wall motion and quantitative LV ejection fraction (LVEF). The 17 myocardial segments for each patient were scored for myocardial perfusion by stress gated SPECT, and regional wall motion by stress gated SPECT and echo. Of the 459 myocardial segments, 41% had perfusion defects, 15% had stress gated SPECT regional wall motion abnormality, 4.8% had poststress echo regional wall motion abnormality, and 3.9% had baseline regional wall motion abnormality. Overall, a stress gated SPECT regional wall motion abnormality had a sensitivity of 100% and a specificity of 89%. Among reversible perfusion defects of moderate severity or more, a stress gated SPECT regional wall motion abnormality had a specificity of 41% and a positive predictive value of 8%. Stress gated SPECT LVEF was similar to poststress echo LVEF for all patients, but significantly lower in patients with reversible perfusion defects of moderate severity or more. Post-stress gated SPECT imaging overestimates global and regional myocardial stunning. Caution should be exercised in interpreting poststress global or regional LV function on stress gated SPECT in scans with reversible ischemia.

Prognostic value of poststress left ventricular volume and ejection fraction by gated myocardial perfusion SPECT in women and men: Gender-related differences in normal limits and outcomes

Whether there are gender differences in the prognostic application of gated myocardial perfusion single photon emission computed tomography (SPECT) has not been assessed. Gender-specific normal limits of poststress volume and ejection fraction (EF) were obtained in 597 women and 824 men with a low likelihood of coronary artery disease and normal perfusion and were applied in a prognostic evaluation of 6713 patients (2735 women and 3978 men). Patients underwent rest thallium-201/stress technetium-99m sestamibi gated myocardial perfusion SPECT and were followed up for 35 +/- 14 months. The upper limit of the end-systolic volume (ESV) index was 27 mL/m2 in women and 39 mL/m2 in men, and the upper limit of the end-diastolic volume index was 60 mL/m2 in women and 75 mL/m2 in men. The lower limit of the EF was 51% in women and 43% in men. Gated SPECT variables provided incremental prognostic information in both genders. Women with severe ischemia and an EF lower than 51% or an ESV index greater than 27 mL/m2 were at very high risk of cardiac death or myocardial infarction (3-year event rates of 39.8% and 35.1%, respectively), whereas women with severe ischemia but an EF of 51% or greater or an ESV index of 27 mL/m2 or less were at intermediate or high risk (3-year event rates of 10.8% and 15.2%, respectively). Poststress EF and ESV index by gated myocardial perfusion SPECT provide comparable incremental prognostic information over perfusion in women and men. After separate criteria for abnormal EF and ESV index in women are used, the combination of severe ischemia and abnormal EF or ESV index identifies women at very high risk of cardiac events.

Ischaemic related transitory left ventricular dysfunction in 201Tl gated SPECT

To report our data concerning the changes in post-stress and at-rest left ventricular ejection fraction and ventricular volumes in patients with thallium gated SPECT. Post-stress and at-rest thallium gated SPECT was performed in 629 consecutive patients; left ventricular ejection fraction (LVEF), left ventricular volumes and quantitative perfusion data were obtained. Transitory left ventricular dysfunction was diagnosed when post-stress LVEF did not increase at least 5% from LVEF at-rest. In all patients post-stress LVEF was 64%+/-17 while at-rest LVEF was 66%+/-15 (P=0.6). Post-stress end diastolic volume (EDV) was 142 ml+/-7, at-rest EDV was 141 ml+/-92 (P=0.57), post-stress end systolic volume (ESV) was 54 ml+/-51 and at-rest ESV was 56 ml+/-59 (P=0.38). Data from the perfusion study were used to divide patients into three groups: normal patients (group I), patients with total or partially reversible defects (group II) and patients with fixed defects (group III). In group I and group III patients LVEF at-rest was lower than post-exercise (LVEF 75%+/-11 vs 81%+/-10 (P<0.001) and 57%+/-16 vs 60%+/-18 (P=0.025)), respectively. Patients in group II had a higher at-rest LVEF than post-exercise (LVEF 66%+/-14 vs 64%+/-16 (P=0.003)). While the left ventriuclar volumes in group I and III patients decreased with exercise, group II patients had increased post-stress ESV. Post-stress and at-rest LVEF are similar when all patients are considered but significant differences appear when patients are divided according to the results of the perfusion study. Normal and fixed defect patients have increased post-exercise LVEF. Patients with reversible defects have decreased LVEF, which is largely due to an increased ESV. Transitory left ventricular dysfunction is related to the presence of reversibility and may benefit from revascularization.

Prognostic Value of Combined Perfusion and Function by Stress Technetium-99m Sestamibi Gated SPECT Myocardial Perfusion Imaging in Patients With Suspected or Known Coronary Artery Disease

The incremental prognostic value of combined regional wall motion and perfusion over perfusion alone by gated single-photon emission computed tomographic myocardial perfusion scintigraphy has not been evaluated. Of the 402 consecutive patients who underwent stress single-photon emission computed tomographic myocardial perfusion scintigraphy for suspected myocardial ischemia, we identified 333 patients (217 men, mean age 63 +/- 10 years; exercise in 249 and dipyridamole adminstered to 84). Visual scoring of perfusion images and regional wall motion used 20 segments and a scale of 0 to 4. Resting and poststress left ventricular ejection fraction was automatically generated. On follow-up (median 13 months), 30 hard cardiac events (17 cardiac deaths, 13 nonfatal acute myocardial infarctions) and 66 total cardiac events (including hard events, 26 with unstable angina, and 10 who underwent late revascularization) occurred. After adjustment for prescan information, the best independent predictors of hard events were summed stress score for wall motion (Wald's chi-square 8.3, p <0.004) and several vascular territories with ischemia by perfusion/function (Wald's chi-square 6.2, p <0.01). The strongest predictors of all cardiac events were the number of ischemias (Wald's chi-square 32.1, p <0.0001) and the number of ischemic vascular territories by perfusion (Wald's chi-square 13.1, p <0.0001). Addition of function data to the combined model of perfusion data yielded an incremental value of 26% for predicting hard events but not for all events. In conclusion, the assessment of combined perfusion/function provides incremental prognostic information for further hard events with perfusion data alone; perfusion data best predict all cardiac events.

Prognostic value of ECG-gated thallium-201 single-photon emission tomography in patients with coronary artery disease

The phenomenon of reversible impairment in LV function has been well described and is known as myocardial stunning. Thallium-201 myocardial perfusion gated SPECT was used to evaluate myocardial stunning and its incremental prognostic value in patients with coronary artery disease. Fifty-six patients (aged 63+/-11 years) with coronary artery disease were included in this study. All subjects underwent exercise thallium scintigraphy. ECG-gated SPECT was obtained both at post-stress (10 minutes after the injection of 111 MBq of thallium at the time of peak exercise) and at rest (180 minutes). The left ventricular ejection fraction (LVEF) and end-systolic and end-diastolic volume (ESV, EDV) were determined by a quantitative gated SPECT (QGS) program. Follow-up was complete in all patients (mean 569 days). The magnitude of the depression of post-stress LVEF relative to the rest LVEF was correlated with the severity of ischemia (p < 0.05). The group with a median LVEF of more than 45% had a significantly higher event-free rate (p < 0.01). Assessment of post-stress left ventricular function by gated-SPECT provides incremental prognostic information and is useful in predicting cardiac events in patients with suspected or definite coronary artery disease.

Predictors of differences in left ventricular ejection fraction and volumes determined by quantitative gated rest and post-stress Tc-99m sestamibi SPECT

Background: Quantitative gated SPECT (QGS) is useful in evaluating left ventricular ejection fraction (LVEF), end systolic volume (ESV), and end diastolic volume (EDV). Less is known regarding factors potentially associated with differences in LVEF and volumes obtained from QGS at rest and post-stress. Methods: Using a 2-day protocol, SPECT data was obtained at rest and post-stress with high dose (25 mCi) Tc-99m sestamibi bolus. LVEF, ESV, and EDV were derived from automated Cedars-Sinai QGS software. Of 100 patients prospectively studied, 92 studies were technically adequate. Delta LVEF was defined as QGS rest EF minus QGS post-stress LVEF. Delta ESV and EDV were similarly defined. Results: (See table). LVEF, ESV, and EDV rest and post-stress were highly correlated. LVEF and EDV were higher at rest than post-stress. Summed difference score (SDS) >0 was significantly associated with increased delta LVEF (p=0.02). Mean LVEF post-stress in ischemic patients was 55.0% vs 61.1% in nonischemic patients (p=0.01). SDS=0 was associated with increased delta EDV (p<0.001). Mean post-stress EDV in ischemic patients was 94.4 cc vs 80.1 cc in nonischemic patients (p<0.01). SDS=0 was associated with increased delta ESV (p=0.002). Mean post-stress ESV in ischemic patients was 43.4 cc vs 32.1 cc in nonischemic patients (p<0.01). Conclusion: QGS post-stress is highly correlated with QGS rest for LVEF, EDV, and ESV. The mean QGS rest LVEF and rest EDV are significantly higher than post-stress LVEF and stress EDV. Ischemia is associated with lower QGS post-stress LVEF which may represent post-stress ischemic LV dilatation with increased post-stress ESV and EDV. Rest Post-Stress r p Mean delta p LVEF (%) 61.1 59.2 0.89 <0.001 1.9 <0.001 EDV (cc) 88.1 84.8 0.88 <0.001 3.3 <0.01 ESV (cc) 35.4 35.8 0.93 <0.001 −0.4 NS

Gated-spect imaging using vasodilating stressor for risk stratification of subjects with or without coronary artery disease

Dipiridamole stress myocardial SPECT is known to be able to stratify the risk of cardiovascular disease, but there are not data about the additional value of post-stress and rest left ventricular ejection fraction (LVEF), by gated-SPECT (gS) analysis, in the same exam. Aim of our study was to evaluate the stratification of risk matching parameters of perfusion and LV function using stress-dipyridamole/rest gS. Methods: 1008 consecutive patients (pts) (715 males, mean age 69 years) performed stress-dipyridamole Tc-99 tetrofosmin gS (0.56 mg/Kg of dypiridamole in 4 minutes). For the imaging study we adopted a dual-day stress/rest protocol. Both post-exercise and resting images were gated and acquired 20–30 minutes after injection of technetium 99m-tetrofosmin (after 3 minutes from finish of infusion of dypiridamole) using a dual-head camera. Perfusion quantitation (SSS, SRS, SDS), and LVEF were automatically calculated with the use of Autoquant™ software package. The perfusion was normal when SSS < 4 and the LVEF > 45%. The follow-up for hard cardiac events (cardiac death or myocardial infarction) was 18,5 ± 7.5 months and completated in 902 pts (89.4%). Results: The frequency of cardiac events/year was major in pts with SSS > 4 (14/393, 3.7%) vs pts with normal perfusion (4/615, 0.7%) and in pts with post-stress LVEF < 45% (11/191, 5.9%) vs pts with normal LVEF (7/817, 0.9%). The crossing analysis demostreted a major rate of cardiac events in pts with significative reduction of left ventricular function (LVEF < 45%) and perfusion defects (SSS > 4). (see table). Conclusions: The evalutation of perfusion and LV function in the same exam (Gated-SPECT) even using dipyridamole stressor provides an additional value for statification of cardiovascular risk in pts with or without suspected CAD. LVEF normal LVEF < 45% P SSS < 4 (4/584, 0.8%) (1/31, 3.2%) 0.035 SSS > 4 (4/212, 1.8%) (11/181, 6.1%) 0.0001

1170-144 Abnormal hemodynamic response to adenosine and poststress left ventricular ejection fraction provide incremental prognostic information in patients undergoing gated myocardial perfusion SPECT

1170-144 Abnormal hemodynamic response to adenosine and poststress left ventricular ejection fraction provide incremental prognostic information in patients undergoing gated myocardial perfusion SPECT

Post-stress Measurements of Left Ventricular Function With Gated Perfusion SPECT: Comparison with Resting Measurements by using Exercise and Adenosine Stress

Background and Objectives:This study examined the relationship between myocardial perfusion defects in single photon emission tomography (SPECT) and the difference in the left ventricular functional parameters obtained after stress and at rest. Materials and Method:Eighty five patients known to have or were suspected to have coronary artery disease (CAD) underwent gated Tc-99m sestamibi SPECT using a one or separate day rest/stress protocol. The post-stress left ventricular ejection fraction (LVEF-s) was compared with that at rest (LVEF-r). Myocardial stunning was blieved to have developed when the LVEF was >5% lower than that at rest. Results:Forty one (48%) patients demonstrated reversible or irreversible perfusion defects in the gated perfusion SPECT (group 1). Forty four (52%) patients demonstrated a normal perfusion status (group 2). In group 1, the LVEF-s was significantly lower than that at rest ([mean±SD] 46±15.5 vs 48±16.0 respectively, p 5% lower than the LVEF-r. Conclusion:The LVEF obtained after stress with gated SPECT may not reflect the true resting values. It is recommended that gated myocardial perfusion SPECT should be performed also at rest especially in patients with myocardial perfusion defects. (Korean Circulation J 2001;31(10):1019-1026)

Gated single-photon emission tomography imaging protocol to evaluate myocardial stunning after exercise.

This study was designed to apply ECG-gating to stress myocardial perfusion single-photon emission tomography (SPET) for the evaluation of myocardial stunning after exercise. Technetium-99m sestamibi was selected as the perfusion agent and a rest/exercise 1-day protocol was employed. Fourteen patients without coronary stenosis and 33 patients with coronary stenosis were enrolled in the study. We carried out three data acquisitions with ECG-gating: a 15-min data acquisition starting 30 min after the rest injection (AC1), a 5-min acquisition starting 5 min after the stress injection (AC2) and a 15-min acquisition starting 20 min after the stress injection (AC3). Calculation of left ventricular ejection fraction (LVEF) values was performed by means of automatic determination of the endocardial surface for all gating intervals in the cardiac cycle. Measured global EF values in 14 patients without coronary stenosis were 52.3% +/- 7.6% (AC1), 60.6% +/- 8.9% (AC2) and 55.6% +/- 5.6% (AC3), and those in 11 patients with severe ischaemia were 53.6% +/- 8.0% (AC1), 45.6% +/- 12.1% (AC2) and 49.7% +/- 10.7%. The magnitude of the depression of post-stress LVEF relative to the rest LVEF correlated with the severity of ischaemia (r = 0.594, P = 0.002), and segments manifesting post-stress functional depression were associated with ischaemic segments showing reversible perfusion defects. Stress myocardial perfusion SPET with ECG-gating is a feasible method for the evaluation of myocardial stunning as well as exercise-induced ischaemia.