Prognostic value of normal stress myocardial perfusion imaging in Japanese population.

BACKGROUND: In Japan, Diagnosis Procedure Combination (DPC) of hospitalization health-care costs has been introduced since 2004, and its introduction has been recently expanded also to general hospitals. In such situations, the role of nuclear cardiology as a gatekeeper for the diagnosis of ischemic heart disease is increasingly important. Thus, the present study was designed to determine which clinical risk for hard events after normal single-photon emission computed tomography (SPECT) images, identify the predictors of increased risk in patients with normal SPECT images based on the J-ACCESS study. METHODS AND RESULTS: A total of 4,629 consecutively tested patients who underwent stress (99m)Tc-tetrofosmin SPECT at hospitals in Japan were included in the study. Based on SPECT image data, 1,862 participants had a summed stress score of or=49% in men, EF >or=55% in women), which is defined as selection criteria III (normal perfusion, ESV and EF). During the 3-year follow-up period, there was a total of 211 cardiac events (11.3%) in patients grouped in selection criteria I, 196 cardiac events (11.0%) in patients grouped in selection criteria II, and 189 cardiac events in patients grouped in selection criteria III (10.8%). The annual hard event rates were 0.81%, 0.67% and 0.63% in selection criteria I, II and III, respectively. Cox proportional hazard analysis showed that diabetes mellitus, age and hypertension were independent predictors of all cardiac events in all selection criteria. CONCLUSION: Normal stress myocardial perfusion imaging in the Japanese population is associated with a low cardiac event risk. The prognosis results of a normal SPECT scan would be useful for better patient management.     

Effect of sex, age, and weight on ejection fraction and end-systolic volume reference limits in gated myocardial perfusion SPECT.

BACKGROUND: The left-ventricular ejection fraction (EF) and end-systolic volume (ESV) are strong predictors of prognosis for cardiac death. Gated myocardial perfusion single-photon emission computed tomography (gSPECT) may be used to measure ESV and EF. However, systematic differences may exist between referred populations. Our aim was to derive male and female reference limits for left-ventricular functional parameters, and determine the effect of age, weight, and body surface area (BSA). METHODS AND RESULTS: The ejection fraction and ESV were derived using QGS software for 127 patients with normal gSPECT studies. The lower reference limits of EF were 46.2% and 55.6% for men and women, respectively. The upper reference limits of ESV were 30.4 mL and 21.4 mL, and 15.7 mL/m(2) and 11.1 mL/m(2), when indexed to BSA for men and women, respectively. There was no correlation between EF and age, weight, or BSA (P > .05). There was a small decrease in ESV with age, and an increase with weight and BSA (P < .05). The sex-specific differences remained after adjusting for confounding variables. CONCLUSIONS: We demonstrated a significant sex difference for all functional parameters measured, and we established the influence of patient age and weight. Local reference limits for ESV and EF have been established, and the latter are transferable to other departments operating similar protocols.     

Usefulness of combination post-stress dysfunction and perfusion imaging in technetium-99m-tetrofosmin myocardial scintigraphy

OBJECTIVES: Myocardial perfusion imaging has lower sensitivity for the diagnosis of coronary artery disease in patients with three-vessel disease. The presence of post-stress dysfunction of the left ventricle, evaluated by electrocardiography(ECG) gated single photon emission computed tomography(SPECT) with a quantitative gated SPECT program, was investigated in patients with coronary artery disease, and also whether combining post-stress dysfunction and myocardial perfusion imaging improved the diagnosis of coronary artery disease. METHODS: ECG gated technetium-99m-tetrofosmin SPECT was performed using a one day, stress and rest, protocol in 139 patients. SPECT and coronary angiography were performed within 1 month. The coronary artery disease group consisted of 89 patients: 43 with one-vessel disease(1VD), 28 with two-vessel disease(2VD), and 18 with three-vessel disease(3VD). The group with zero-vessel disease(0VD) consisted of 50 patients. According to post-stress and rest ejection fraction(EF) and end-systolic volume (ESV), post-stress dysfunction is defined as follows: rest EF--post-stress EF > or = 5% and post-stress ESV--rest ESV > or = 5 ml. RESULTS: In the coronary artery disease group, post-stress ESV was larger than rest ESV(37.8 +/- 26.4, 34.0 +/- 24.2 ml, p < 0.001), and post-stress EF was lower than rest EF (61.5 +/- 11.1%, 64.2 +/- 10.8%, p < 0.001). In the 0VD group, ESV and EF were the same for post-stress and rest (25.7 +/- 20.8, 26.2 +/- 21.6 ml, NS; 70.4 +/- 9.5%, 70.0 +/- 9.6%, NS). Post-stress dysfunction was 6.0% in the 0VD group and 30.3% in the coronary artery disease group(p < 0.001). Furthermore, post-stress dysfunction in the 2VD (35.7%) and 3VD(38.9%) groups was higher than that in the 0VD group(p < 0.01, p < 0.01). Sensitivity of coronary artery disease diagnosis by myocardial perfusion imaging was 75%. The combination of post-stress dysfunction and myocardial perfusion imaging improved sensitivity from 75% to 82%(p < 0.05), but reduced the specificity from 92% to 86%(p = 0.08). CONCLUSIONS: Post-stress dysfunction is a useful parameter for clinical diagnosis of coronary artery disease.     

Influence of the postexercise acquisition delay on the detection of functional abnormalities in sestamibi-gated SPECT.

BACKGROUND: Gated single photon emission computed tomography (SPECT) identifies functional changes produced by ischemia, but the influence of acquisition delay on their detection is not established. METHODS AND RESULTS: In 80 patients with known or suspected coronary artery disease, gated SPECT was acquired twice: first, less than 30 minutes after peak exercise (stress 1), and second, more than 45 minutes after peak exercise (stress 2). End-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were compared with perfusion. The relationship between the DeltaEF (stress EF - resting EF) and the summed difference score (SDS) was -0.443 (P < .0001) for stress 1 and -0.416 (P < .0001) for stress 2. In stress 1, EF increased in patients without inducible ischemia (SDS = 0) (57% +/- 10% vs 54% +/- 9% at rest, P < .02) and decreased in those with an SDS of 1 or greater (53% +/- 10.8% vs 55% +/- 9.6% at rest, P < .05). In stress 2, EF was unchanged in patients without ischemia (55.8% +/- 9.7%, P = .06) and decreased in the other patients (52.8% +/- 10.2%, P < .01). In patients without ischemia, both the EDV and ESV decreased significantly in stress 1 and were unchanged in stress 2. In patients with an SDS of 1 or greater, the EDV remained unchanged and the ESV minimally decreased in stress 1, whereas both volumes clearly and significantly increased in stress 2. CONCLUSIONS: The early acquisition of postexercise gated SPECT is slightly more effective in detecting ischemia-related functional changes; however, a delayed acquisition within 60 minutes still permits the detection of functional abnormalities in most patients.     

Differences in left ventricular ejection fraction and volumes measured at rest and poststress by gated sestamibi SPECT.

BACKGROUND: Some studies suggested that the poststress left ventricle ejection fraction (LV EF) is lower than rest LV EF in patients with stress-induced ischemia. METHODS AND RESULTS: By using a 2-day protocol and 30 mCi Tc-99m sestamibi, LV EF, end-systolic volume (ESV), and end-diastolic volume (EDV) were measured with gated SPECT. Of 99 eligible patients, 91 had technically adequate studies. Poststress LV EF minus rest LV EF was defined as DeltaLV EF. DeltaEDV and DeltaESV were similarly defined. Rest and poststress LV EF (r = 0.89), EDV (r = 0.78), and ESV (r = 0.93) were highly correlated (P <.001). Rest LV EF, EDV, and ESV were not significantly different between patients with and without stress-induced ischemia. DeltaLV EF was significantly lower in patients with stress-induced ischemia (-3.5% +/- 4.5% vs -1.1% +/- 4.7%, P = .02). Mean LV EF poststress in ischemic patients was 55.0% +/- 10.5% vs 61.2% +/- 10.0% in nonischemic patients (P = .008). However, only 1 patient (3%) with ischemia had DeltaLV EF that exceeded the 95% confidence limit of DeltaLV EF for normal patients. Ischemia was significantly associated with increased DeltaEDV and DeltaESV (P < .01). CONCLUSIONS: Stress-induced ischemia is associated with poststress reduction in LV EF and increased poststress EDV and ESV. However, the effect of ischemia on the difference between poststress and rest EF measurements is modest and rarely exceeds the confidence limits in normal patients undergoing 2-day protocols. In most patients, poststress LV EF is an accurate reflection of rest LV EF.     

Detection of occult left ventricular dysfunction in patients without prior clinical history of myocardial infarction by technetium-99m sestamibi myocardial perfusion gated single-photon emission computed tomography

BACKGROUND: In the absence of a prior history of myocardial infarction (MI), left ventricular (LV) dysfunction is commonly due to hypertension, valvular heart disease, or hibernating myocardium. HYPOTHESIS: Since technetium-99m sestamibi gated single-photon emission computed tomography (SPECT) may be used to determine both stress/rest myocardial perfusion and resting LV function, we attempted to evaluate the ability of gated SPECT imaging to detect occult LV dysfunction. METHODS: We evaluated the ability of this technique to detect occult LV dysfunction among 179 patients without history MI and angiographically documented coronary artery disease (CAD). All patients underwent both gated SPECT and cardiac catheterization within a 6-month time period. Left ventricular volume and ejection fraction (EF) values were determined according to a previously validated technique using Simpson's rule. Normal limit values for LV volumes and EF were derived from a control population of 93 patients with normal coronary angiograms. RESULTS: Based on normal limit-derived criteria, 15% of the CAD study cohort had occult LV dysfunction (> 2 standard deviations below gender-specific normal limit means for LVEF). Mean LV end-diastolic volume index (EDVi) was significantly increased (p < 0.05) and LVEF decreased (p < 0.05) in patients with triple-vessel CAD. End-diastolic volume index was also increased in the cohort of patients with both hypertension and LV hypertrophy (LVH) (p < 0.05). However, multivariate logistic regression analysis revealed that only CAD extent, but not hypertension or LVH, was a significant predictor of occult LV dysfunction (p = 0.009). CONCLUSION: Occult LV dysfunction can be detected in patients with CAD by gating technetium-99m sestamibi SPECT studies, and its presence may signify the presence of extensive CAD.     

Diagnostic value of left ventricular function after stress and at rest in the detection of multivessel coronary artery disease as assessed by electrocardiogram-gated SPECT.

BACKGROUND: Although transient left ventricular (LV) dilation is a well-known marker for extensive coronary artery disease (CAD), few studies have performed quantitative analysis of LV function after stress and at rest to detect extensive CAD. METHODS AND RESULTS: Poststress and resting gated single photon emission computed tomography (SPECT) was performed in 175 patients with suspected CAD. All of the patients underwent coronary angiography within 3 months of gated SPECT. In the 83 patients with multivessel CAD, the summed difference score was greater (9.2 +/- 7.0 vs 3.3 +/- 4.0, P < .0001), the poststress increase in end-systolic volume (ESV) was larger (7.0 +/- 8.0 mL vs -0.8 +/- 4.7 mL, P < .0001), and the poststress increase in ejection fraction (EF) was less (-4.7% +/- 5.4% vs -0.4% +/- 4.5%, P < .0001) than in the 92 patients with insignificant or single-vessel CAD. In the detection of multivessel CAD, a summed difference score of 9 or greater showed a sensitivity of 46% and specificity of 90%, whereas an increase in ESV of 5 mL or greater and a decrease in EF of 5% or greater after exercise had a sensitivity of 66% and 52%, respectively, and specificity of 87% and 83%, respectively. The multivariate discriminant analysis revealed that the combination of poststress increase in ESV, summed difference score, and diabetes mellitus best identified multivessel CAD, with a sensitivity of 72% and specificity of 84% (chi(2), 81.7). CONCLUSIONS: The addition of poststress and at-rest LV functional analysis by use of gated SPECT to conventional perfusion analysis helps to better identify patients with multivessel CAD.     

Multicenter intercomparison assessment of consistency of left ventricular function from a gated cardiac SPECT phantom.

BACKGROUND: A multicenter intercomparison assessment was made of the variation in left ventricular (LV) volumes and ejection fractions (EFs) obtained from gated myocardial perfusion single photon emission computed tomography (SPECT) of the 3-dimensional AGATE (Amsterdam gated) cardiac phantom. METHODS AND RESULTS: The phantom was configured to produce 3 different standard end-systolic volume and end-diastolic volume combinations (50 mL and 120 mL, 90 mL and 160 mL, and 120 mL and 190 mL) with corresponding EF (58%, 44%, and 37%). Quantitative gated myocardial perfusion SPECT was performed with 39 SPECT systems in 35 departments. In the multicenter study, for all 3 filling conditions, a wide range of results was obtained. The EF was overestimated (by 1% to 15%), and both the end-systolic volume and end-diastolic volume were underestimated (by 1 to 65 mL). The extent of overestimation of EF was related to the extent of underestimation of the volumes and was independent of filling condition. The trend in error per center was comparable for all 3 filling conditions. Acquisition time per projection was the only independent predictor of the difference between measured and expected EF (P = .0001). CONCLUSIONS: Care should be taken before extrapolation of published and accepted cutoff values for LV EF and volumes in clinical decision making. Results should be validated in each center and monitored for accuracy and consistency over time.     

Performance of thallium-201 electrocardiography-gated myocardial perfusion single photon emission computed tomography to assess left ventricular function

This study evaluated the performance of gated single photon emission computed tomography (SPECT) with thallium-201 (201Tl) in assessing left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) in Taiwanese by determining repeatability and correlation with two-dimensional (2D) echocardiography. A total of 18 patients underwent two sequential gated SPECT acquisitions within 30 minutes in the resting state to assess repeatability. Another 28 patients who underwent gated SPECT and 2D echocardiography within 7 days were included for comparison. The two sequential measurements were well correlated with respect to LVEF, EDV, and ESV (r = 0.97, 0.95, and 0.97, respectively, all p < 0.0001). Bland-Altman analysis revealed that two standard deviations of the absolute difference between the two sequential measurements for LVEF, EDV, and ESV were 6.4%, 16.8 mL, and 8.6 mL, respectively. For LVEF, EDV, and ESV, correlations between redistribution 201Tl-gated SPECT and echocardiography were also excellent (all r = 0.83, p < 0.0001). LVEF was similar with 201Tl-gated SPECT and echocardiography, but EDV and ESV were significantly higher with echocardiography (p < 0.05). Our study revealed that 201Tl-gated SPECT has high repeatability and excellent correlation with echocardiography for the assessment of LVEF and volumes in Taiwanese. These results support the clinical application of gated SPECT in routine 201Tl myocardial perfusion imaging in Taiwanese.     

Comparison of cardiac magnetic resonance with gated SPECT for evaluation of left ventricular function and volumes in patients with severe and multiple myocardial perfusion defects

Objectives

Gated SPECT is an accurate technique for assessment of myocardial perfusion (MP), left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV). However recent studies have concluded that there are large discrepancies in assessment of LVEF and volumes by gated SPECT in patients with multiple severe myocardial perfusion defects. We sought to investigate the correlation between LVEF and volumes calculated by gated SPECT and cardiac magnetic resonance (CMR) in patients with severe multiple perfusion defects who are referred for CMR.

Methods

Twenty-nine patients (20 male and 9 female, mean age: 63 years ± 11) with multiple severe fixed perfusion defects (mean 5 ± 3 segments) were referred to undergo CMR. The average time between CMR and SPECT was 4 weeks. LVEF, EDV, and ESV were derived automatically from gated SPECT. In the CMR studies, the endocardial and epicardial borders were delineated manually in the short axis planes to calculate the LVEF and volumes.

Results

The different parameters were compared using linear regression, and correlation coefficients were calculated. Substantial correlation was found between CMR and gated SPECT for EDV: r = 0.7, p < 0.001. Moderate correlation between CMR and gated SPECT for LVEF: r = 0.5, p < 0.007 and ESV r =0 .53, p < 0.003.

Conclusion

Our data showed that the gated SPECT correlates substantially with MRI for measurement of EDV and moderately for ESV and LVEF in patients with multiple and severe perfusion defects. Thus, when accurate measurement is required, cardiac MRI is recommended.     

Evidence for left ventricular remodeling after percutaneous coronary intervention: effect of percutaneous coronary intervention on left ventricular ejection fraction and volumes

BACKGROUND: Post-stress ejection fraction (EF), end-diastolic (EDV) and end-systolic (ESV) volumes by gated myocardial perfusion SPECT (MPS) are well validated, reproducible and of prognostic significance. However, little is known about the impact of percutaneous coronary intervention (PCI) on left ventricular volumes and remodeling. METHODS: Thirty-eight patients who underwent MPS before and 6 months after PCI were evaluated. MPS were interpreted deriving summed stress (SSS), rest (SRS) and difference (SDS = SSS-SRS; extent of ischemia) scores. EF, EDV and ESV were generated by QGS trade mark. Pre-PCI MPS were compared to post-PCI MPS. RESULTS: Single vessel disease was present in 63% of patients. PCI of one vessel was performed in 82% of patients. After 6 months, SSS (10.6 +/- 6.3 vs. 2.8 +/- 4.3, p < 0.001) and SDS (8.2 +/- 5.6 vs. 1.4 +/- 2.3, p < 0.001) had improved; however, EF did not change significantly (55 +/- 10 vs. 57 +/- 13, p = ns). Still, EDV (105 +/- 25 ml vs. 96 +/- 25 ml, p = 0.006) and ESV (49 +/- 19 ml vs. 41 +/- 18 ml, p = 0.001) were significantly reduced. CONCLUSION: Results of MPS documented the beneficial effect of PCI on symptoms and extent of ischemia. In addition, the findings showed a significant decrease in ESV and EDV after PCI as compared to pre-PCI findings which points to a positive effect on left ventricular remodeling even in the absence of significant changes in EF.     

Prognostic value of gated SPECT in patients with left bundle branch block.

BACKGROUND: The aim of this study was to assess the prognostic value of quantitative gated technetium 99m tetrofosmin single photon emission computed tomography (SPECT) imaging in patients with left bundle branch block (LBBB). METHODS AND RESULTS: We followed up 101 consecutive patients with LBBB using Tc-99m tetrofosmin gated SPECT imaging. The mean follow-up was 1.24 years (maximum, 2.48 years). Hard endpoints were all-cause death and acute myocardial infarction. Event-free survival curves were obtained. Optimal cutoff points for left ventricular (LV) volumes and LV ejection fraction (EF) to predict outcome were determined by receiver operating characteristic curve analysis. Of the patients, 94 had an abnormal study. Fifteen hard events occurred (thirteen deaths). Perfusion abnormalities were similar for patients with or without events. For LV function parameters, the survival curves were maximally separated when we used cutoff values of 160 mL or greater for end-diastolic volume (P = .019 and hazard ratio [HR] of 1.04 for hard events, P = .024 and HR of 1.04 for all-cause death), 100 mL or greater for end-systolic volume (P = .043 and HR of 1.04 for hard events, P = .062 and HR of 1.04 for all-cause death), and lower than 35% for LVEF (P = .013 and HR of 0.81 for hard events, P = .047 and HR of 0.81 for all-cause death). CONCLUSION: By use of quantitative gated SPECT imaging, LBBB patients with an end-diastolic volume of 160 mL or greater, end-systolic volume of 100 mL or greater, or LVEF lower than 35% are at increased risk for subsequent cardiac events.     

Myocardial scintigraphy by the gated SPECT method in coronary disease patients with postischemic stunning

Gated SPECT using Tc-99m-labeled flow tracers provides simultaneous assessment of global and regional myocardial perfusion and function. The aim of this study was to evaluate whether regional wall thickening (WT) obtained after stress and at rest makes it possible to identify and analyze a subgroup of post-ischemic stunned patients. METHODS: We studied 20 patients (18 males) who underwent conventional diagnostic dual-day stress/rest Gated SPECT following injection of 925 MBq of 99mTc-tetrofosmin using a dual-head SPECT camera (Vertex ADAC). The mean age of these patients was 59 years (38-71) and 10 of them had a history of previous acute myocardial infarction (AMI). Perfusion was analyzed on ungated images using 20 segments scored on a 5-point scale (0 = normal, 4 = no uptake), while WT and motion were assessed visually on stress/rest end-systolic images using a 4-point score (0 = normal, 3 = absence of WT/motion). Left ventricular ejection fraction (LVEF) and volumes were calculated. All patients underwent coronary angiography. RESULTS: All patients showed at least one reversible defect with post-stress WT reduction and normal rest WT. The stunned group showed a significant post-stress reduction of LVEF and a statistically non-significant increase of end systolic volume (ESV). A good correlation was observed between global perfusion and WT score both at stress and rest conditions; LVEF showed a significant inverse correlation with global post-stress and rest perfusion and WT score. ESV and the global perfusion stress/rest score showed a good correlation, while end-diastolic volume did not correlate. In 44% of the segments with fixed defects, there was a normal WT and normal coronary-related vessel (false positives); 28% of reversible segments showed a post-stress pathological WT and five of them a rest pathological WT. CONCLUSIONS: The gated SPECT myocardial perfusion evaluation allowed us to analyze a subgroup of post-stress stunned coronary artery disease patients. The post-stress LVEF reduction in this population seems to be due to the increase of end-systolic volume caused by endocardial ischemia. The stunned segments showed severe perfusion defects.     

Scintigraphic determination of ventricular function and coronary perfusion in long-distance runners

Left ventricular function and coronary perfusion were evaluated with rest-exercise gated blood pool and stress-redistribution thallium scans in a group of long-distance runners and compared to a group of catheterization-proved normal subjects. Exercise duration, work load, and oxygen consumption were significantly greater for long-distance runners. Rest end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volumes (SV) were significantly larger in long-distance runners than in control subjects, while ejection fraction (EF), cardiac index (CI), and ejection rate were similar in both groups. Exercise EDV increased and ESV decreased, producing an increase in SV and EF in long-distance runners. Exercise EDV did not change and ESV decreased less, producing lesser increase in SV and EF in the control group. Qualitative evaluation of thallium scans showed apparent perfusion defects with normal redistribution in six myocardial segments in five long-distance runners. Quantitative evaluation demonstrated initial defects, which persisted on delay scans, but were associated with normal relative redistribution in three ventricular walls in three long-distance runners. In conclusion, left ventricular reserve function was greater in long-distance runners than in control subjects. Endurance exercise can be associated with apparent myocardial perfusion defects, which may be due to uneven ventricular hypertrophy resulting from the pressure and volume loads imposed by exercise.     

Comparison of post-exercise and post-vasodilator stress myocardial stunning as assessed by electrocardiogram-gated single-photon emission computed tomography.

BACKGROUND: Exercise gated single-photon emission computed tomography (SPECT) using technetium-99m (99mTc)-sestamibi evaluates both myocardial perfusion during stress and wall motion >30 min after the stress, which has the potential to assess not only exercise-induced myocardial ischemia but also the development of myocardial stunning. METHODS AND RESULTS: To evaluate the incidence of post-stress myocardial stunning, as well as comparing the effects of different stress methods on the development of stunning, 179 consecutive patients with known or suspected coronary artery disease (CAD) underwent (99m)Tc-sestamibi SPECT with either exercise (n=135) or adenosine triphosphate disodium (ATP) (n=44). Electrocardiogram-gated SPECT images were acquired >30 min after the stress and again 4 h later, and perfusion and wall motion were evaluated. Post-stress myocardial stunning occurred in 24 patients (13%): 22 after exercise and 2 after ATP stress. The magnitude of the transient wall motion abnormality after exercise was greater in patients with severe ischemia, compared with those with mild-to-moderate ischemia (p<0.0001). By contrast, with ATP stress, the magnitude of the transient wall motion abnormality was similar, regardless of the severity of perfusion abnormality. Furthermore, a significant correlation between summed difference score and transient wall motion abnormality was found after exercise (r=0.68, p<0.0001). With ATP, however, no such correlation was observed (r=0.28, p=NS). CONCLUSIONS: Using 99mTc-sestamibi gated SPECT, myocardial stunning is frequently observed after exercise and correlates with the severity of myocardial ischemia, but this does not occur with ATP, which is regarded as a specific marker for severe CAD.     

99mTc-MIBI门电路SPECT对冠心病的诊断和心肌存活性评价的作用

为进一步评价99m锝-甲氧基异睛(99mTc-MIBI)门电路和非门电路单光子发射断层显像(SPECT)对冠心病的诊断价值及硝酸甘油介入诊断试验在心肌存活状态评价中的作用,对40例进行运动心肌灌注断层显象,并与冠状动脉(冠脉)造影比较.结果32例冠脉造影显示冠脉有意义狭窄.门电路断层显象对冠心病诊断总的敏感和特异性分别为93.8%和87.5%;非门电路断层显象分别为84.4%和87.5%,两相比较,无显著性差异(P＞0.05).对冠脉病变支数诊断敏感性门电路方法优于非门电路方法(分别为73.8%和62.3%,P＜0.05).特异性均为96.6%.20例进行含服硝酸甘油后静态心肌灌注断层显象,16例心肌梗死病人中有3例为部分可逆性心肌灌注缺损,4例慢性心肌缺血病人,全部有可逆性心肌灌注.表明硝酸甘油介入诊断试验有助于心肌灌注异常可逆性的评估;99mTc-MIBI门电路SPECT和硝酸甘油介入诊断试验是有效的对冠心病无创性诊断和心肌存活状态评价方法.     

Identification of severe and extensive coronary artery disease by postexercise regional wall motion abnormalities in Tc-99m sestamibi gated single-photon emission computed tomography

Postexercise wall motion abnormality (WMA) in patients with normal resting myocardial perfusion may represent prolonged postischemic stunning, and may be related to the presence of severe angiographic coronary artery disease (CAD). This study assesses the diagnostic value of postexercise WMA by technetium-99m (Tc-99m) sestamibi gated single-photon emission computed tomography (SPECT) in patients with normal resting perfusion. Ninety-nine patients underwent exercise gated Tc-99m sestamibi/resting thallium-201 SPECT and coronary angiography within 90 days of nuclear testing. All patients had normal perfusion at rest. Multivariate logistic regression analysis demonstrated an incremental value of wall motion and perfusion over perfusion data alone in identifying severe and extensive CAD. Sensitivity for identifying any severely stenosed coronary artery by WMA was significantly higher than by severe perfusion defect (78% vs 49%, p <0.0001). Overall specificities of severe perfusion defect and WMA were 91% and 85%, respectively (p = NS). Thus, postexercise WMA detected by gated Tc-99m sestamibi SPECT in patients with normal resting perfusion is a sensitive marker of severe and extensive CAD.     

Detection of ischemia with thallium-201 single photon emission computerized tomography (SPECT) and radionuclide ventriculography in comparison with stress cineventriculography

The accuracy of radionuclide techniques for detection of exercise-induced myocardial ischemia was analyzed with TL-201 single-photon emission computer tomography (SPECT) and gated blood pool ventriculography in 31 patients. Reversible and persistent perfusion defects in the biphasic SPECT studies, parametric phase and amplitude images and global indices of left ventricular function were evaluated and compared to the results of exercise cineventriculography. Out of 25 patients with coronary heart disease, 20 had exercise-induced ischemia and 17 patients had a prior myocardial infarction. SPECT detected ischemia with a sensitivity of 85% and a specificity of 100%, gated blood pool ventriculography had a sensitivity of 60% and a specificity of 91%. Both scintigraphic methods were comparable in the detection of myocardial infarcts (SPECT/gated blood pool ventriculography: sensitivity 88%/82%; specificity 100%/93%; positive predictive value 100%/93%). A difference in detection of ischemia between both methods was found in patients with myocardial infarct and additional ischemia: all patients with additional ischemia were detected by SPECT, whereas gated blood pool ventriculography failed to identify the additional ischemia in 1/4 of these patients (p less than 0.05).     

Outcome of patients with adenosine-induced ST-segment depression but with normal perfusion on tomographic imaging

Most patients with ST depression during adenosine infusion have reversible perfusion defects by single-photon emission computed tomographic (SPECT) perfusion images. Occasionally ST depression is observed in the setting of normal perfusion images. The outcome of such patients is controversial. We identified 65 patients who underwent gated SPECT perfusion imaging with adenosine as the stress agent. These patients were selected based on the following criteria: none had previous myocardial infarction or coronary revascularization, all were in sinus rhythm, and none had left bundle branch block. The 65 patients had normal SPECT images but ischemic ST response (>or=1 mm ST depression). There were 52 women and 13 men who were 66 +/- 13 years of age. History of diabetes mellitus was present in 16 patients (25%) and hypertension in 48 patients (74%). At a mean follow-up of 24 months, there were no cardiac deaths or myocardial infarctions, and there were 6 coronary revascularization procedures (2 coronary artery bypass graftings and 4 coronary stentings of 1-vessel coronary disease). One patient died of cancer. In conclusion, patients with no previous myocardial infarction or coronary revascularization who have normal SPECT images have a benign outcome despite the presence of ST depression (0% for death or myocardial infarction and 4.6%/year for coronary revascularization). Balanced ischemia could not be a common cause for discordant perfusion and ST response.     

Association of heart rate response with scan and left ventricular function on adenosine myocardial perfusion imaging.

To evaluate the association of heart rate (HR) response with abnormal scan and/or left ventricular (LV) function in patients undergoing adenosine myocardial perfusion imaging, we retrospectively studied 188 consecutive patients who underwent a standard adenosine stress test (without exercise) and myocardial perfusion imaging (MPI) using technetium-99m sestamibi radioisotope. Change in HR was calculated by subtracting HR at rest from peak HR. The percentage change in HR was calculated. All patients underwent stress and resting single-photon emission computed tomography (SPECT) imaging. LV ejection fraction (EF) was calculated using gated SPECT. Mean age was 60 +/- 12 years and 135 of the patients (72%) were women. We divided the patients into 2 groups: group 1 (142 patients, 75%) had normal scans and group 2 (46 patients, 25%) had abnormal scans; abnormal scans were defined as presence of either fixed defects, reversible defects, or both. Average HR increased by 29 beats/min in the normal scan group compared with 19 beats/min in the abnormal scan group (p = 0.0004). Forty-seven patients (25%) had reduced EF (<45%). This group had an average HR and percentage HR increase of 20 beats/min (29%) compared with an increase of 29 beats/min (44%) in patients with normal EF (p = 0.002 and p = 0.002, respectively). Thus, a diminished HR response had a significant association with both an abnormal scan and reduced EF on adenosine MPI.