A case of cardiac sarcoidosis mimicking acute phase of takotsubo cardiomyopathy evaluated by multimodality cardiac imaging.

The patient was a 68-year-old woman who experienced loss of consciousness owing to a seizure while walking and bruised her face. Twelve­lead electrocardiography displayed a complete atrioventricular block. Transthoracic echocardiography displayed hypokinesis from the middle to apex of the myocardium. Emergency coronary angiography displayed no clear stenosis of the coronary arteries, and left ventriculography displayed takotsubo-like abnormal left ventricular wall motion. 99mTc-sestamibi/123I-beta-methyl iodophenyl pentadecanoic acid dual single-photon emission computed tomography displayed a perfusion/metabolism mismatch in the left apex, anterior segment, and inferior segment of the myocardium in the acute phase, which improved in the chronic phase. Similar mismatch findings were observed in the ventricular septum, which persisted in the chronic phase. Blood biomarkers of sarcoidosis were positive. Myocardial delayed enhancement was observed in the mid layer of the basal septum and inferior wall on cardiac magnetic resonance imaging. Fluorodeoxyglucose-positron emission tomography displayed signal accumulation in the basal septum. The clinical course of the patient suggested the possibility of cardiac sarcoidosis combined with takotsubo cardiomyopathy. This is a valuable case in which changes over time were detected by multimodality cardiac imaging. Learning objective: Cardiac manifestations of both takotsubo cardiomyopathy and sarcoidosis are similar, with both causing abnormal left ventricular wall motion. The co-occurrence of these conditions has been seldomly reported to date. The similarity of the characteristics of each condition poses a challenge in the diagnostic process. The utilization of multimodality cardiac imaging techniques, as demonstrated in the present case, is an effective means of establishing a diagnosis.

Potential of non-contrast stress T1 mapping for the assessment of myocardial injury in hypertrophic cardiomyopathy.

BACKGROUND: Ischemia of the hypertrophied myocardium due to microvascular dysfunction is related to a worse prognosis in hypertrophic cardiomyopathy (HCM). Stress and rest T1 mapping without contrast agents can be used to assess myocardial blood flow. Herein, we evaluated the potential of non-contrast stress T1 mapping in assessing myocardial injury in patients with HCM. METHODS: Forty-five consecutive subjects (31 HCM patients and 14 control subjects) underwent cardiac magnetic resonance (CMR) at 3T, including cine imaging, T1 mapping at rest and during adenosine triphosphate (ATP) stress, late gadolinium enhancement (LGE), and phase-contrast (PC) cine imaging of coronary sinus flow at rest and during stress to assess coronary flow reserve (CFR). PC cine imaging was performed on 25 subjects (17 patients with HCM and 8 control subjects). Native T1 values at rest and during stress were measured using the 16-segment model, and T1 reactivity was defined as the change in T1 values from rest to stress. RESULTS: ATP stress induced a significant increase in native T1 values in both the HCM and control groups (HCM: p < 0.001, control: p = 0.002). T1 reactivity in the HCM group was significantly lower than that in the control group (4.2 ± 0.3% vs. 5.6 ± 0.5%, p = 0.044). On univariate analysis, T1 reactivity correlated with native T1 values at rest, left ventricular mass index, and CFR. Multiple linear regression analysis demonstrated that only CFR was independently correlated with T1 reactivity (ß = 0.449; 95% confidence interval, 0.048-0.932; p = 0.032). Furthermore, segmental analysis showed decreased T1 reactivity in the hypertrophied myocardium and the non-hypertrophied myocardium with LGE in the HCM group. CONCLUSIONS: T1 reactivity was lower in the hypertrophied myocardium and LGE-positive myocardium compared to non-injured myocardium. Non-contrast stress T1 mapping is a promising CMR method for assessing myocardial injury in patients with HCM. Trial registration Retrospectively registered.

Prognostic Implications of Sarcoidosis Granulomas　- Insights From the Multicenter Registry, the Japanese Cardiac Sarcoidosis Prognostic Study.

Background: Definitions of cardiac sarcoidosis (CS) differ among guidelines. Any systemic histological finding of CS is essential for the diagnosis of CS in the 2014 Heart Rhythm Society statement, but not necessary in the Japanese Circulation Society 2016 guidelines. This study aimed to reveal the differences in outcomes by comparing 2 groups, namely CS patients with or without systemic histologically proven granuloma. Methods and Results: This study retrospectively included 231 consecutive patients with CS. CS with granulomas in ≥1 organs was diagnosed in 131 patients (Group G), whereas CS without any granulomas was diagnosed in the remaining 100 patients (Group NG). Left ventricular ejection fraction (LVEF) was significantly reduced in Group NG compared with Group G (44±13% vs. 50±16%, respectively; P=0.001). However, Kaplan-Meier curves showed that major adverse cardiovascular events (MACE)-free survival outcomes were comparable between the 2 groups (log-rank P=0.167). Univariable analyses showed that significant predictors of MACE were Groups G/NG, histological CS, LVEF, and high B-type natriuretic peptide (BNP) or N-terminal pro BNP concentrations, but none of these was significant in multivariable analyses. Conclusions: Overall risks of MACE were similar between the 2 groups despite different manifestations in cardiac dysfunction. The data not only validate the prognostic value of non-invasive diagnosis of CS, but also show the need for careful observation and therapeutic strategy in patients with CS without any granuloma.

Multicenter Registry in the Japanese Cardiac Sarcoidosis Prognostic (J-CASP) Study: Baseline Characteristics and Validation of the Non-invasive Approach Using 18F-FDG PET.

Background: Recent advances in cardiac modalities contribute to the guidelines on the diagnosis of cardiac sarcoidosis (CS) updated by the Japanese Circulation Society. The multicenter registry, Japanese Cardiac Sarcoidosis Prognostic (J-CASP) study tried to reveal recent trends of diagnosis and outcomes in CS patients and to validate the non-invasive diagnostic approach, including cardiac 18F-fluorodeoxyglucose (FDG) study. Methods/results: Databases from 12 hospitals consisting of 231 CS patients (mean age, 64 years; female, 65%; LV ejection fraction, 47%) diagnosed by the guidelines with FDG positron emission tomography (PET) study were integrated to compile clinical information on the diagnostic criteria and outcomes. Cardiac 18F-FDG uptake and magnetic resonance imaging (CMR) was positive identically in the histology-proven and clinically-diagnosed groups. The histology-proven group more frequently had reduce LV ejection fraction, myocardial perfusion abnormality and low-grade electrocardiogram (ECG) abnormality (P=0.003 to 0.016) than did the clinical group. During a 45-month period, the histology-proven group more frequently underwent appropriate implantable cardioverter-defibrillator (ICD) treatment (14% versus 4%, P=0.013) and new electronic device implantation (30% versus 12%, P=0.007) than did clinical group, respectively. There, however, was no difference in all-cause or cardiac mortality or in new hospitalization due to heart failure progression between them. Conclusion: The J-CASP registry demonstrated the rationale and clinical efficacies of non-invasive approach using advanced cardiac imaging modalities in the diagnosis of CS even when histological data were available.

Association of the extent of myocardial ischemia with outcomes in patients with suspected coronary artery disease in Japan.

BACKGROUND: There is an ongoing controversy regarding the necessity of single-photon emission computed tomography (SPECT) for patients with ischemic heart diseases after the publication of the results of the ISCHEMIA trial. We aimed to evaluate the association of the extent of myocardial ischemia with outcomes in patients with suspected coronary artery disease in Japan. METHODS: From the data of 2780 patients with stable angina who were enrolled prospectively between January 2006 and March 2008 in Japan and had undergone physician-referred non-invasive imaging tests (Japanese Coronary-Angiography or Myocardial Imaging for Angina Pectoris Study), 1205 patients managed with SPECT were stratified by 10 % myocardial ischemia. Major adverse cardiac events (MACEs), including death, myocardial infarction, hospitalization for heart failure, and late revascularization, were followed-up for 1 year. RESULTS: Patients with ≥10 % myocardial ischemia (n = 173) were less likely to be women than patients with <10 % myocardial ischemia (n = 1032) and had a significantly higher 1-year cumulative incidence of MACEs (6.9 % vs. 1.8 %, p < 0.0001). After adjusting for confounders, the risk of ≥10 % myocardial ischemia relative to <10 % myocardial ischemia for MACEs remained significant [adjusted hazard ratio (95 % confidence interval), 2.40 (1.09-5.26), p = 0.029]. After adjusting including treatments, the risk of MACEs became insignificant between the ≥10 % myocardial ischemia group and the <10 % myocardial ischemia group [adjusted hazard ratio (95 % confidence interval), 1.04 (0.45-2.45), p = 0.92]. CONCLUSION: The presence of ≥10 % myocardial ischemia at diagnosis was significantly associated with the 1-year risk for MACEs in Japanese patients with suspected coronary artery disease.

Performance of Hybrid Imaging in the Diagnosis of Coronary Artery Disease.

Single-photon emission computed tomography (SPECT) and computed tomography coronary angiography (CTCA) are usually performed independently in patients with suspected coronary artery disease. We assessed the hypothesis that hybrid SPECT/CTCA imaging results in higher diagnostic accuracy than either method alone, particularly in cases presenting with high levels of coronary calcification. A total of 243 major coronary vessels in 81 patients with known or suspected coronary artery disease were screened using SPECT with semiconductor detectors and CTCA with 256-detector row computed tomography. Patients who were diagnosed with myocardial ischemia underwent coronary angiography. Coronary angiography results were defined as positive for stenosis when the stenosis diameter was >70% or fractional flow reserve was <0.8. These data were then compared with a fused image of the SPECT and CTCA datasets generated using a dedicated workstation. To detect significant coronary artery stenosis, the respective sensitivity, specificity, and accuracy were 73%, 61%, and 67% with SPECT alone, 96%, 44%, and 67% with CTCA alone, and 95%, 75%, and 84% with hybrid imaging. Moreover, hybrid imaging allowed the accurate diagnosis of 47 vessels with severe calcification that CTCA alone could not evaluate correctly. Hybrid imaging shows greater diagnostic accuracy than single-modality evaluation through more comprehensive information on potential coronary stenosis and its hemodynamic significance.

Association of coronary revascularisation after physician-referred non-invasive diagnostic imaging tests with outcomes in patients with suspected coronary artery disease: a post hoc subgroup analysis.

OBJECTIVE: We aimed to evaluate the association of the prognostic impact of coronary revascularisation with physician-referred non-invasive diagnostic imaging tests (single photon emission CT (SPECT) vs coronary CT angiography) for coronary artery disease. DESIGN: A post hoc analysis of a subgroup from the patient cohort recruited for the Japanese Coronary-Angiography or Myocardial Imaging for Angina Pectoris Study. SETTING: Multiple centres in Japan. PARTICIPANTS: From the data of 2780 patients with stable angina, enrolled prospectively between January 2006 and March 2008 in Japan, who had undergone physician-referred non-invasive imaging tests, 1205 patients with SPECT as an initial strategy and 625 with CT as an initial strategy were analysed. We assessed the effect of revascularisation (within 90 days) in each diagnostic imaging stratum and the interaction between the two strata. PRIMARY AND SECONDARY OUTCOME MEASURES: Major adverse cardiac events (MACEs), including death, myocardial infarction, hospitalisation for heart failure and late revascularisation, were followed up for 1 year. The χ2 test, Student's t-test, Kaplan-Meier analysis, log-rank test and multivariable Cox proportional hazard model were used in data analysis. RESULTS: A total of 210 (17.4%) patients in the SPECT stratum and 149 (23.8%) in the CT stratum underwent revascularisation. Although in each stratum, the cumulative 1 year incidence of MACEs was significantly higher in patients who underwent revascularisation than in those who did not (SPECT stratum: 9.1 vs 1.2%, log-rank p<0.0001; CT stratum: 6.1 vs 0.8%, log-rank p=0.0001), there was no interaction between the risk of revascularisation and the imaging strata (SPECT stratum: adjusted HR (95% CI), 4.25 (1.86-9.72); CT stratum: 4.13 (1.16-14.73); interaction: p=0.97). CONCLUSION: The association of revascularisation with the outcomes of patients with suspected coronary artery disease was not different between SPECT-first and CT-first strategies in a physician-referred fashion.

Impact of renal dysfunction on the choice of diagnostic imaging, treatment strategy, and outcomes in patients with stable angina.

We investigated the interaction between the prognostic impact of a decrease in eGFR and the choice of initial diagnostic imaging modality for coronary artery disease. Out of 2878 patients who enrolled in the J-COMPASS study, 2780 patients underwent single photon emission computed tomography (SPECT), coronary computed tomography (CT) angiography, or coronary angiography (CAG) as an initial diagnostic test. After excluding patients with routine hemodialysis or lacked serum creatinine levels, 2096 patients in the non-decreased eGFR group (eGFR ≥ 60 ml/min/1.73 m2) and 557 patients in the decreased eGFR group (eGFR < 60 ml/min/1.73 m2) were analyzed in this study. Major adverse cardiac events, including death, myocardial infarction, heart failure hospitalization, and late revascularization, were followed, with a median follow-up duration of 472 days. SPECT or CAG was preferable to CT in patients in the decreased eGFR group (p < 0.0001 and p = 0.0024, respectively). There was a marginally significant interaction between the prognostic impact of a decrease in eGFR and the choice of diagnostic imaging modality (interaction-p = 0.056). A decrease in eGFR was not associated with a poor outcome in patients who underwent CT, while a decrease in eGFR was associated with poor outcomes in patients who underwent SPECT or CAG. In conclusion, the prognostic impact of a decrease in eGFR tended to be different among the initial imaging modalities.

Long-term events after physician-referred initial tests by myocardial perfusion imaging or computed tomography coronary angiography in patients with suspected coronary artery disease.

BACKGROUND: The effects of initial tests on long-term events have been unknown. PATIENTS AND METHODS: In this observational retrospective study, we analyzed the effects of initial noninvasive tests by myocardial perfusion imaging (MPI) and computed tomography angiography (CTA) on long-term major adverse cardiac events (MACEs) among patients with suspected coronary artery disease during a median follow-up of 8.1 years (interquartile range: 7.7-8.9). RESULTS: Sex difference in the rate of abnormal findings on initial tests was observed in both the MPI (female vs. male: 32.6 vs. 55.5%; P<0.0001) and CTA groups (30.6 vs. 47.9%; P<0.0001). Early revascularization in the MPI was significantly lower than that in the CTA (16 vs. 23%; P=0.0005). A total of 109 MACEs (39 of 1830 patients during the original follow-up period and 70 of 616 patients during the extended follow-up period) occurred: 77 MACEs (6.4%) in the MPI group and 32 (5.1%) in the CTA group (adjusted hazard ratio for MPI: 0.78; 95% confidence interval: 0.50-1.23; P=0.29). In the total cohort, the risk-adjusted MACE rate in the females was ∼50% of the males. CONCLUSION: The long-term MACE rates did not differ between physician-referred initial tests of MPI and CTA despite a higher frequency of early revascularization in the CTA group. In this extended cohort, female sex was associated with a lower rate of positive findings and a lower MACE rate compared with the male sex.

Application of pressure-derived myocardial fractional flow reserve in chronic hemodialysis patients.

BACKGROUND: Although fractional flow reserve (FFR) measurements during coronary angiography are performed in routine clinical practice, few studies have evaluated FFR measurements in dialysis patients. METHODS: We retrospectively studied 42 hemodialysis patients with suspected or known coronary artery disease (CAD) who underwent stress myocardial perfusion imaging and coronary angiography with FFR measurements for 61 coronary lesions. The cut-off value for FFR to detect myocardial ischemia was determined by receiver operating characteristic (ROC) curve analysis. RESULTS: There were 61 coronary vessels measured by FFR. The FFR range was 0.34-0.93 with a mean of 0.74±0.13. The ROC curve analysis revealed that the best cut-off value of FFR for detecting myocardial ischemia was 0.76 (p<0.0001), with 70% sensitivity, 86% specificity, and 76% accuracy for myocardial ischemia. Compared with patients who had positive myocardial ischemia and an FFR≤0.76, those who had negative myocardial ischemia despite an FFR≤0.76 had less left ventricular (LV) mass index, whereas patients who had positive myocardial ischemia despite an FFR>0.76 had greater LV mass indexor serum calcium-phosphorus product. CONCLUSIONS: The cut-off value of FFR for myocardial ischemia in chronic hemodialysis patients is similar to that in other CAD patients. However, caution is necessary when FFR measurements are applied to dialysis patients with significantly increased LV mass index or serum calcium-phosphorus product.

Diagnostic accuracy of an artificial neural network compared with statistical quantitation of myocardial perfusion images: a Japanese multicenter study.

PURPOSE: Artificial neural networks (ANN) might help to diagnose coronary artery disease. This study aimed to determine whether the diagnostic accuracy of an ANN-based diagnostic system and conventional quantitation are comparable. METHODS: The ANN was trained to classify potentially abnormal areas as true or false based on the nuclear cardiology expert interpretation of 1001 gated stress/rest 99mTc-MIBI images at 12 hospitals. The diagnostic accuracy of the ANN was compared with 364 expert interpretations that served as the gold standard of abnormality for the validation study. Conventional summed stress/rest/difference scores (SSS/SRS/SDS) were calculated and compared with receiver operating characteristics (ROC) analysis. RESULTS: The ANN generated a better area under the ROC curves (AUC) than SSS (0.92 vs. 0.82, p < 0.0001), indicating better identification of stress defects. The ANN also generated a better AUC than SDS (0.90 vs. 0.75, p < 0.0001) for stress-induced ischemia. The AUC for patients with old myocardial infarction based on rest defects was 0.97 (0.91 for SRS, p = 0.0061), and that for patients with and without a history of revascularization based on stress defects was 0.94 and 0.90 (p = 0.0055 and p < 0.0001 vs. SSS, respectively). The SSS/SRS/SDS steeply increased when ANN values (probability of abnormality) were >0.80. CONCLUSION: The ANN was diagnostically accurate in various clinical settings, including that of patients with previous myocardial infarction and coronary revascularization. The ANN could help to diagnose coronary artery disease.

Diagnostic performance of a semiconductor gamma-camera system as studied by multicenter registry.

BACKGROUND: Despite the introduction of the novel cadmium-zinc-telluride (CZT) single-photon emission computed tomography (SPECT) in Japan; its diagnostic value in clinical practice remains largely unknown. METHODS: The Semiconductor SPECT Study group is a multicenter Japanese registry which registered 1000 patients to evaluate the diagnostic utility of the CZT camera system (Discovery NM530c; GE Healthcare, Haifa, Israel). The patients underwent stress myocardial SPECT and coronary angiography within a 3-month interval. A significant stenosis was defined as ≥75% diameter narrowing based on the American Heart Association classification. RESULTS: Technetium (99mTc) radiotracer (555-1110MBq) was used in 71% and thallium-201 (201Tl) (74-148MBq) in 29%. The scan times with 99mTc-radiotracer were 5-10min for stress and 3-10min for rest, whereas those with 201Tl were 5-9min for stress and 8-10min for rest. To detect individual coronary stenosis, the respective sensitivities, specificities, and accuracies were 74%, 85%, and 81% for left anterior descending coronary artery (LAD) stenosis, 76%, 89%, and 85% for left circumflex stenosis, and 72%, 86%, and 82% for right coronary artery stenosis. However, 66% sensitivity and 91% specificity for LAD stenosis were observed with 99mTc-radiotracer, whereas 88% sensitivity and 63% specificity were found with 201Tl. CONCLUSIONS: The novel CZT SPECT system facilitated a short scan time with reduced radiotracer dose, yielding an acceptable diagnostic performance for angiographical coronary artery disease, although the low sensitivity for LAD detection with 99mTc-radiotracer needs to be refined.

Diagnostic Performance of a Cadmium-Zinc-Telluride Single-Photon Emission Computed Tomography System With Low-Dose Technetium-99m as Assessed by Fractional Flow Reserve.

BACKGROUND: Although stress single-photon emission computed tomography (SPECT) using a cadmium-zinc-telluride (CZT) camera facilitates radiation dose reduction, only a few studies have evaluated its diagnostic accuracy in Japanese patients by applying fractional flow reserve (FFR) measurements. METHODS AND RESULTS: We prospectively evaluated 102 consecutive patients with suspected or known coronary artery disease with a low-dose stress/rest protocol ((99m)Tc radiotracer 185/370 MBq) using CZT SPECT. Within 3 months, coronary angiography was performed and a significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or as a lesion of <90% and ≥ 50% stenosis with FFR ≤0.80. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 86%, 75%, and 82% for left anterior descending artery stenosis, 76%, 81%, and 79% for left circumflex artery stenosis, and 87%, 92%, and 90% for right coronary artery stenosis. When limited to 92 intermediate stenotic lesions in which FFR was measured, stress SPECT showed 77% sensitivity, 91% specificity, and 84% accuracy, whereas the diagnostic value decreased to 52% sensitivity, 68% specificity, and 58% accuracy based only on visual estimation of ≥75% diameter narrowing. CONCLUSIONS: CZT SPECT demonstrated a good diagnostic yield in detecting hemodynamically significant coronary stenoses as assessed by FFR, even when using a low-dose (99m)Tc protocol with an effective dose ≤5 mSv. (Circ J 2016; 80: 1217-1224).

Diagnostic performance of a novel cadmium-zinc-telluride gamma camera system assessed using fractional flow reserve.

BACKGROUND: Although the novel cadmium-zinc-telluride (CZT) camera system provides excellent image quality, its diagnostic value using thallium-201 as assessed on coronary angiography (CAG) and fractional flow reserve (FFR) has not been validated. METHODS AND RESULTS: To evaluate the diagnostic accuracy of the CZT ultrafast camera system (Discovery NM 530c), 95 patients underwent stress thallium-201 single-photon emission computed tomography (SPECT) and then CAG within 3 months. Image acquisition was performed in the supine and prone positions after stress for 5 and 3 min, respectively, and in the supine position at rest for 10 min. Significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or a lesion with <90% and ≥50% stenosis and FFR ≤0.75. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 90%, 64%, and 78% for left anterior descending coronary artery stenosis, 78%, 84%, and 81% for left circumflex stenosis, and 83%, 47%, and 60% for right coronary artery (RCA) stenosis. The combination of prone and supine imaging had a higher specificity for RCA disease than supine imaging alone (65% vs. 47%), with an improvement in accuracy from 60% to 72%. CONCLUSIONS: Using thallium-201 with short acquisition time, combined with prone imaging, CZT SPECT had a high diagnostic yield in detecting significant coronary stenosis as assessed using FFR.

Usefulness of phase analysis to differentiate ischemic and non-ischemic etiologies of left ventricular systolic dysfunction in patients with heart failure.

BACKGROUND: The detection of significant coronary artery disease (CAD) in patients with heart failure (HF) from left ventricular (LV) systolic dysfunction is crucial. We evaluated the usefulness of LV mechanical dyssynchrony as assessed by phase analysis compared with conventional gated single-photon emission computed tomography to identify ischemic etiology in patients with HF. METHODS AND RESULTS: Forty-one consecutive patients who were initially admitted to hospital due to HF resulting from systolic dysfunction were evaluated. All patients underwent cardiac catheterization. LV mechanical dyssynchrony was evaluated using SyncTool™ to obtain the phase SD and histogram bandwidth. The changes in phase SD and histogram bandwidth with stress were calculated. The summed stress score, summed difference score, and changes in phase SD and histogram bandwidth with stress were greater in 26 patients with CAD than in 15 patients without CAD (P=0.001 and P=0.01). On multivariate analysis a phase SD of >14° (odds ratio [OR], 16.7) and a summed stress score of >17 (OR, 8.0) best differentiated LV dysfunction of ischemic and non-ischemic etiologies, with a sensitivity of 89% and a specificity of 87% (χ(2)=20), compared with summed stress score only (sensitivity, 46%; specificity, 87%; χ(2)=4.5). CONCLUSIONS: The addition of phase analysis to conventional perfusion analysis enables better differentiation of the etiology of HF in patients with systolic dysfunction.

Relationship of SYNTAX score to myocardial ischemia as assessed on myocardial perfusion imaging.

BACKGROUND: Although the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score is used to characterize coronary anatomy based on 9 anatomic criteria such as lesion location and complexity, the relationship between SYNTAX score and myocardial ischemia has yet to be elucidated. METHODS AND RESULTS: A total of 158 consecutive patients with suspected or known coronary artery disease (CAD), who underwent both (99m)Tc-sestamibi single-photon emission computed tomography (SPECT) and coronary angiography, were evaluated. Stress SPECT was assessed using a 17-segment model, and the percentage of the myocardial defect scores (DS) was calculated. In 37 patients with intermediate-high SYNTAX scores (>22), the number of men and the prevalence of multi-vessel CAD were significantly higher, and the % stress and ischemic DS were significantly greater than in 121 patients with low SYNTAX scores (≤22). Coronary risk factors, however, were similar between the 2 groups. The % stress and ischemic DS significantly correlated with SYNTAX score. In patients with a low SYNTAX score, % stress and ischemic DS also significantly correlated with the SYNTAX score, whereas no such correlation was observed in the intermediate-high SYNTAX score group. CONCLUSIONS: SYNTAX score correlated well with myocardial ischemia as assessed on stress SPECT in general. The higher the SYNTAX score, however, the less clear was the correlation with the extent of myocardial ischemia.

Comparison of myocardial perfusion imaging between the new high-speed gamma camera and the standard anger camera.

BACKGROUND: Cadmium-zinc-telluride (CZT) solid-state detectors have been recently introduced into the field of myocardial perfusion imaging. The aim of this study was to prospectively compare the diagnostic performance of the CZT high-speed gamma camera (Discovery NM 530c) with that of the standard 3-head gamma camera in the same group of patients. METHODS AND RESULTS: The study group consisted of 150 consecutive patients who underwent a 1-day stress-rest (99m)Tc-sestamibi or tetrofosmin imaging protocol. Image acquisition was performed first on a standard gamma camera with a 15-min scan time each for stress and for rest. All scans were immediately repeated on a CZT camera with a 5-min scan time for stress and a 3-min scan time for rest, using list mode. The correlations between the CZT camera and the standard camera for perfusion and function analyses were strong within narrow Bland-Altman limits of agreement. Using list mode analysis, image quality for stress was rated as good or excellent in 97% of the 3-min scans, and in 100% of the ≥4-min scans. For CZT scans at rest, similarly, image quality was rated as good or excellent in 94% of the 1-min scans, and in 100% of the ≥2-min scans. CONCLUSIONS: The novel CZT camera provides excellent image quality, which is equivalent to standard myocardial single-photon emission computed tomography, despite a short scan time of less than half of the standard time.

Diagnostic value of left ventricular dyssynchrony after exercise and at rest in the detection of multivessel coronary artery disease on single-photon emission computed tomography.

BACKGROUND: Although stress-induced left ventricular (LV) wall motion abnormality is a well-known marker for extensive coronary artery disease (CAD), no study has yet analyzed whether phase analysis of exercise-induced LV mechanical dyssynchrony may have enhanced diagnostic value over conventional perfusion analysis in the detection of multivessel CAD. METHODS AND RESULTS: A total of 278 patients with suspected or confirmed CAD underwent both exercise stress (99m)Tc-sestamibi gated single-photon emission computed tomography and coronary angiography. LV mechanical dyssynchrony was evaluated using the SyncTool to obtain the phase SD and histogram bandwidth. In the detection of 128 patients with multivessel CAD, a summed stress score (SSS) of ≥9 showed a sensitivity of 84% and a specificity of 53%, while an increase in phase SD of ≥4.4° and a bandwidth of ≥14° after exercise had sensitivities of 74% and 68%, and specificities of 84% and 91%, respectively. On multivariate analysis the combination of post-stress increases in phase SD, histogram bandwidth, transient ischemic dilation (TID) ratio and SSS best identified multivessel CAD (sensitivity 77%, specificity 88%, χ(2)=181.8), compared with TID ratio and SSS only (sensitivity 70%, specificity 76%, χ(2)=68.9). CONCLUSIONS: The addition of phase analysis to evaluate exercise-induced LV mechanical dyssynchrony on conventional perfusion analysis enabled better identification of patients with multivessel CAD.

Postischemic myocardial stunning is superior to transient ischemic dilation for detecting multivessel coronary artery disease.

BACKGROUND: Although poststress myocardial stunning is regarded as a marker for severe coronary artery disease (CAD), no study has yet compared the diagnostic value of poststress stunning with transient ischemic dilation (TID) of the left ventricle (LV) for detecting multivessel CAD. METHODS AND RESULTS: A total of 271 patients with suspected or known CAD underwent adenosine triphosphate (ATP) loading and at-rest gated single-photon emission computed tomography. We assessed myocardial perfusion with a 20-segment model, and analyzed the changes in LV volumetric analysis induced by ATP and an automatically derived TID ratio. In 147 patients with multivessel CAD, the prevalence of multi-territorial ischemia was higher, and the post-ATP increase in end-systolic volume (ESV) and TID ratio were greater, than in the 124 with insignificant or single-vessel CAD (P<0.0001, for all cases). The receiver-operating characteristic curves analysis revealed cutoff values for ESV of 5 ml and a TID ratio of 1.11. Multivariate logistic regression analysis revealed that the combination of a poststress increase in ESV of ≥5 ml and multi-territorial ischemia best identified multivessel CAD, with a sensitivity of 78% and a specificity of 84%, whereas the TID ratio was not shown to be an independent predictor. CONCLUSIONS: Post-ATP stress myocardial stunning is superior to the TID ratio for detecting multivessel CAD.