Left ventricular shape index and eccentricity index with ECG-gated Nitrogen-13 ammonia PET/CT in patients with myocardial infarction, ischemia, and normal perfusion.

BACKGROUND: LV geometry with shape index (SI) and eccentricity index (EI) measured by myocardial perfusion positron emission tomography/computed tomography (PET/CT) may allow the evaluation of left ventricular (LV) adverse remodeling. This first study aims to explore the relationship of SI and EI values acquired by Nitrogen-13 ammonia PET/CT in patients with normal perfusion, ischemia, and myocardial infarction. And evaluate the correlations between the variables of LV geometry, and with the variables of LV function. METHODS AND RESULTS: One hundred and forty patients who underwent an electrocardiogram (ECG)-gated PET/CT were selected and classified into 4 groups according to ischemia or infarction burden (normal perfusion, mild ischemia, moderate-severe ischemia, and infarction). The variables were automatically retrieved using dedicated software (QPS/QGS; Cedars-Sinai, Los Angeles, CA, USA). On multicomparison analysis (one-way ANOVA and Dunnett's Test), subjects in the infarction group had significant higher values of SI end-diastolic rest (P < 0.001), and stress (P = 0.003), SI end-systolic rest (P = 0.002) and stress (P < 0.001) as well as statistically significant lower values of EI rest (P < 0.001) and stress (P < 0.001) when compared with all other groups. Regarding Pearson correlation, in the infarcted group all the variables of SI and EI were significantly correlated (P < 0.001) with strong correlation coefficients (>0.60). SI end-systolic correlated significantly with the variables of LV function independently of the group of patients (P < 0.05). CONCLUSIONS: Shape and eccentricity indices differ in patients with myocardial infarction as compared to patients with ischemia or normal perfusion. This encourage further research in their potential for detecting LV adverse remodeling.

Diagnosis, performance and added value of assessing ventricular dyssynchrony by phase analysis in patients with three-vessel disease: A single-center cross-sectional study in Mexico.

BACKGROUND: Three-vessel disease (3VD) is a cardiovascular disorder that affects the three main coronary arteries. Gated myocardial perfusion SPECT (GMPS) evaluates ventricular function, synchrony, and myocardial perfusion. However, the diagnostic performance of GMPS parameters to assess 3VD has not been fully explored. AIMS: To assess the univariate performance capacity of GMPS parameters, and to evaluate whether phase parameters could provide additional predictive value for the detection of patients with 3VD compared to control subjects. METHODS: We designed paired retrospective samples of GMPS images of patients with 3VD (stenosis > 70% of left anterior descending, right coronary, and circumflex coronary arteries) and without 3VD. A GMPS in rest-stress protocol was performed using 99mTc-Sestamibi and thallium and analyzed with the 3D method. Area under the receiver-operating characteristic curves (AUROC), decision curve analyses and diagnostic test performance were obtained for univariable analyses and stepwise binomial logistic regression for multivariable performance. RESULTS: 474 Patients were included: 237 with 3VD (84% males, mean age 61.7 ± 9.9 years) and 237 with normal GMPS (51% women, mean age 63.8 ± 10.6 years). The highest AUROC for perfusion parameters were recorded for SSS, SRS and TID. For dyssynchrony parameters, both entropy and bandwidth in rest and stress phases displayed the highest AUROC and diagnostic capacity to detect 3VD. A multivariate model with SRS ≥ 4, SDS ≥ 2, TID > 1.19 and sBW ≥ 48° displayed the highest diagnostic capacity (0.923 [95% CI 0.897-0.923]) to detect 3VD. CONCLUSION: Perfusion and dyssynchrony were the parameters which were most able to discriminate patients with 3VD from those who did not have CAD.

Causes of cardiovascular and noncardiovascular death in the ISCHEMIA trial.

BACKGROUND: The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial demonstrated no overall difference in the composite primary endpoint and the secondary endpoints of cardiovascular (CV) death/myocardial infarction or all-cause mortality between an initial invasive or conservative strategy among participants with chronic coronary disease and moderate or severe myocardial ischemia. Detailed cause-specific death analyses have not been reported. METHODS: We compared overall and cause-specific death rates by treatment group using Cox models with adjustment for pre-specified baseline covariates. Cause of death was adjudicated by an independent Clinical Events Committee as CV, non-CV, and undetermined. We evaluated the association of risk factors and treatment strategy with cause of death. RESULTS: Four-year cumulative incidence rates for CV death were similar between invasive and conservative strategies (2.6% vs 3.0%; hazard ratio [HR] 0.98; 95% CI [0.70-1.38]), but non-CV death rates were higher in the invasive strategy (3.3% vs 2.1%; HR 1.45 [1.00-2.09]). Overall, 13% of deaths were attributed to undetermined causes (38/289). Fewer undetermined deaths (0.6% vs 1.3%; HR 0.48 [0.24-0.95]) and more malignancy deaths (2.0% vs 0.8%; HR 2.11 [1.23-3.60]) occurred in the invasive strategy than in the conservative strategy. CONCLUSIONS: In International Study of Comparative Health Effectiveness with Medical and Invasive Approaches, all-cause and CV death rates were similar between treatment strategies. The observation of fewer undetermined deaths and more malignancy deaths in the invasive strategy remains unexplained. These findings should be interpreted with caution in the context of prior studies and the overall trial results.

13N-Ammonia myocardial blood flow quantitation in patient with aneurismal coronary artery disease.

Aneurysmal coronary artery disease includes coronary artery aneurysms and ectasia; this condition has been associated with poor long-term outcomes. Few studies have explored myocardial blood flow 13N-ammonia PET/CT MPI added value. We present a 45-year-old man who came to the emergency department with chest pain. After a physical examination and laboratory studies, he was diagnosed with very high-risk unstable angina and referred to the catheterization laboratory. Coronary angiography showed the culprit lesion in the LCx and was treated by angioplasty and stent. LAD was found with coronary artery ectasia (TIMI 2 flow grade) and the RCA with aneurysmal disease in the proximal and middle segments (TIMI 3 flow grade). Medical treatment was decided for these findings and the patient was discharged. Two weeks later, we performed a 13N-ammonia PET/CT MPI founding apical, inferior, and inferoseptal severe ischemia, and reduced hyperemic coronary blood flow and coronary flow reserve in the RCA territory. Flow was normal in the LAD territory. Although coronary angiography remains the gold standard for evaluating these coronary abnormalities, it does not show the physiological compromise. Therefore 13N-ammonia PET/CT MPI should be performed as a complementary noninvasive imaging approach.

Diastolic dyssynchrony assessment by gated myocardial perfusion-SPECT in subjects who underwent cardiac resynchronization therapy.

BACKGROUND: Left ventricular diastolic dyssynchrony (LVDD) can be assessed by gated myocardial perfusion single-photon emission computed tomography (GMP-SPECT). LVDD is an area of interest in subjects who underwent cardiac resynchronization therapy (CRT). The aim of this post hoc analysis was to assess the role of LVDD in subjects with CRT who were followed up at 6-month period. MATERIAL & METHODS: Left ventricular diastolic dyssynchrony was assessed by GMP-SPECT at baseline and after CRT procedure in 160 subjects from 10 different cardiological centers. CRT procedure was performed as per current guidelines. Outcomes were defined as improvement in ≥1 New York Heart Association (NYHA) class, left ventricular ejection fraction (LVEF) by 5%, and reduction in end-systolic volume (ESV) by 15% and 5% points in Minnesota Living with Heart Failure Questionnaire. LVDD was defined as diastolic phase standard deviation ≥40 ± 14°. RESULTS: Improvement in NYHA functional class occurred in 105 (65.6%), LVEF in 74 (46.3%), decrease in ESV in 86 (53.8%), and Minnesota score in 85 (53.1%) cases. Baseline LV diastolic standard deviation was 53.53° ± 20.85 and at follow-up 40.44° ± 26.1283; (P < 0.001). LVDD was not associated with improvement in clinical outcomes at follow-up. CONCLUSION: CRT improves both systolic and diastolic dyssynchrony values at 6-month follow-up. LVDD at baseline is correlated with cardiac functionality at follow-up, but not with overall favorable clinical outcomes.

Left ventricular and atrial global strain evaluation within subtypes of ventricular remodeling.

BACKGROUND: Left ventricular hypertrophy is associated with poor prognosis and adverse events. Left ventricular and left atrial global strain and left atrial reservoir strain (LV-GS; LA-GS; LA-RS) could be used as markers for myocardial function in different ventricular remodeling forms. This study aimed to evaluate LV-GS and LA-GS scores in different ventricular remodeling variants and identify risk factors for myocardial dysfunction. METHODS AND RESULTS: This cross-sectional study was divided into four groups of ventricular remodeling: normal geometry, eccentric hypertrophy (EH), concentric hypertrophy (CH), and concentric remodeling (CR). Strain analysis was obtained using standardized protocols. We included 121 subjects, 33 with previous myocardial infarction (MI). We found that EH had the lowest LV-GS and CH, the lowest LA-GS, and LA-RS. Atrial and ventricular dysfunction was present in 40 (33%) and 14 (11.5%) subjects, respectively. Smoking, male sex, and previous MI were associated with LV dysfunction and smoking and dyslipidemia with LA dysfunction; EH was closely associated with LV dysfunction and CH with LA dysfunction. CONCLUSIONS: We conclude that different ventricular geometry types had echocardiographic profiles associated with different risk factors for dysfunction assessed by strain. The assessment of ventricular remodeling by global strain could be used as a complementary tool in the echocardiographic evaluation of ventricular and atrial function.

Can regional training courses reduce interobserver variability?

Cardiovascular disease (CVD) is the principal cause of death worldwide. Noninvasive studies have been used for the evaluation of CVD. Ensuring an accurate diagnosis of CVD requires well-trained and qualified professionals. IAEA has implemented regional training courses which are mainly aimed at professionals from countries with less economic development in order to raise their professional level so that it is in accordance with international standards and thus be able to homogenize the practice of nuclear cardiology globally.

Correction to: Left ventricular dyssynchrony and abnormalities in wall motion, assessed by gated-SPECT as ischemic auxiliary markers.

In Figure 3, sensitivity and specificity were interchanged. The corrected Figure 3 is shown below. The author names listed in reference 14 have been corrected; the correct reference reads: Nakanishi R, Gransar H, Slomka P, Arsanjani R, Shalev A, Otaki Y, et al. Predictors of high-risk coronary artery disease in subjects with normal SPECT myocardial perfusion imaging. J Nucl Cardiol 2016;23:530-41. The units of standard deviation (SD) and bandwidth (BW) in the abstract, results and in table 3 are expressed in degrees from 0 to 360°.

Left ventricular dyssynchrony and abnormalities in wall motion, assessed by gated-SPECT as ischemic auxiliary markers.

INTRODUCTION: Left ventricular dyssynchrony (LVD) quantified by gated myocardial perfusion studies (MPS), through phase analysis (PA), has shown controversial results in myocardial stunning. OBJECTIVES: Assessment of LVD and regional wall motion abnormalities (RWMA) in normal and ischemic patients. METHODS: A cohort of 172 patients were studied. Summed Stress Score (SSS), Summed Resting Score (SRS), and Summed Difference Score (SDS) were evaluated. Group 1-patients with normal MPS (N = 133) and Group 2-patients with myocardial ischemia in the MPS (N = 39). LVD was evaluated through PA and RWM by visual analysis. RESULTS: SSS 0 vs 9.8 ± 3.9 P = .0001; SDS 0 vs 9.8 ± 3.9 P = .0001; SRS 0 vs 0 P = NS, in G1 and G2. Significant differences were found in LVD between G1 and G2, bandwidth 36 ± 14 vs 63 ± 46 P = .0001; standard deviation 16 ± 10 vs 26 ± 15 P = .0001. In G1, 16% had LVD vs RWMA in 0%, P = .0001 and in G2, 59% with LVD vs 33% with RWMA, P = .03. Sensitivity for LVD 59% and for RWMA 33%, P = .03 and specificity for LVD 83% and for RWMA 100%, P = .0001. CONCLUSION: Ischemic patients have LVD post-stress due to myocardial stunning. LVD measured by PA could be a useful tool to identify ischemia.

Software reproducibility of myocardial blood flow and flow reserve quantification in ischemic heart disease: A 13N-ammonia PET study.

BACKGROUND: We explored agreement in the quantification of myocardial perfusion by cross-comparison of implemented software packages (SPs) in three distinguishable patient profile populations. METHODS: We studied 91 scans of patients divided into 3 subgroups based on their semi-quantitative perfusion findings: patients with normal perfusion, with reversible perfusion defects, and with fixed perfusion defects. Rest myocardial blood flow (MBF), stress MBF, and myocardial flow reserve (MFR) were obtained with QPET, SyngoMBF, and Carimas. Agreement between SPs was considered adequate when a pairwise standardized difference was found to be < 0.20 and its corresponding intraclass correlation coefficient was ≥ 0.75. RESULTS: In patients with normal perfusion, two out of three comparisons of global stress MBF quantifications were outside the limits of agreement. In ischemic patients, all comparisons of global stress MBF and MFR were outside the limits of established agreement. In patients with fixed perfusion defects, all SP comparisons of perfusion quantifications were within the limit of agreement. Regionally, agreement of these perfusion estimates was mostly found for the left anterior descending artery vascular territory. CONCLUSION: Reversible defects demonstrated the worst agreement in global stress MBF and MFR and discrepancies showed to be regional dependent. Reproducibility between SPs should not be assumed.

Comorbid conditions in individuals assessed by SPECT: Study of a reference cardiology center in Mexico City.

BACKGROUND: There is an increasing prevalence of comorbidities in patients with ischemic heart disease (IHD) in developing countries. The aim of this work is to assess the prevalence of comorbidities and associated factors for IHD among patients at a reference cardiology center. DESIGN AND METHODS: This was a cross-sectional study. A complete clinical history which focused on the main comorbidities, previous myocardial infarction, and the main reason of referral was assessed. A single-photon emission computed tomography (SPECT) myocardial perfusion study (MPS) with two protocols was performed. RESULTS: We included 1998 patients, 64.2% male, median age 63 (I.R.: 56-71) years. 1514 (75.8%) subjects had at least one associated comorbidity. The main comorbidity was diabetes (T2D) (772: 38.6%), followed by systemic hypertension (737: 36.9%), smoking (518: 25.9%), and dyslipidemia (517: 25.9%). 806 (40.3%) had histories of previous myocardial infarctions. The main cause of referral was angina (923: 46.2%). We identified 1330 (66.5%) abnormal MPS. 460 (23%) had ischemia, 292 (14.6%) infarction, and 578 (28.9%) ischemia and infarction. CONCLUSION: An increased prevalence of comorbidities was found in patients who were studied in the Nuclear Cardiology Department (NCD): most of them had traditional risk factors attributable to myocardial infarction. A great percentage were newly diagnosed with both ischemia and infarction.

An unexpected tumor causing right ventricular obstruction.

A 58-year-old male with a history of a soft tissue sarcoma in remission presented with a 2 weeks history of progressive dyspnea. Transthoracic echocardiography showed right ventricular dilation; right ventricular systolic pressure (RVSP) of 110 mm Hg, and a lobulated mass in the right ventricular outflow tract (RVOT) causing obstruction. Microbubble contrast was administered showing perfusion within the mass, which suggested malignancy. A CT pulmonary angiogram (CTPA) confirmed the presence of the mass in the RVOT without evidence of pulmonary embolism. This case demonstrates the importance of the multimodality imaging approach for the differential diagnosis of masses in the RVOT.