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We compared the prognostic value of myocardial perfusion imaging (MPI) by conventional- (C-) single-photon emission computed tomography (SPECT) and cadmium-zinc-telluride- (CZT-) SPECT in a cohort of patients with suspected or known coronary artery disease (CAD) using machine learning (ML) algorithms. A total of 453 consecutive patients underwent stress MPI by both C-SPECT and CZT-SPECT. The outcome was a composite end point of all-cause death, cardiac death, nonfatal myocardial infarction, or coronary revascularization procedures whichever occurred first. ML analysis performed through the implementation of random forest (RF) and k -nearest neighbors (KNN) algorithms proved that CZT-SPECT has greater accuracy than C-SPECT in detecting CAD. For both algorithms, the sensitivity of CZT-SPECT (96% for RF and 60% for KNN) was greater than that of C-SPECT (88% for RF and 53% for KNN). A preliminary univariate analysis was performed through Mann-Whitney tests separately on the features of each camera in order to understand which ones could distinguish patients who will experience an adverse event from those who will not. Then, a machine learning analysis was performed by using Matlab (v. 2019b). Tree, KNN, support vector machine (SVM), Naïve Bayes, and RF were implemented twice: first, the analysis was performed on the as-is dataset; then, since the dataset was imbalanced (patients experiencing an adverse event were lower than the others), the analysis was performed again after balancing the classes through the Synthetic Minority Oversampling Technique. According to KNN and SVM with and without balancing the classes, the accuracy ( p value = 0.02 and p value = 0.01) and recall ( p value = 0.001 and p value = 0.03) of the CZT-SPECT were greater than those obtained by C-SPECT in a statistically significant way. ML approach showed that although the prognostic value of stress MPI by C-SPECT and CZT-SPECT is comparable, CZT-SPECT seems to have higher accuracy and recall.

Purpose We assessed the impact of COVID-19 infection on cardiovascular events in patients with suspected or known coronary artery disease (CAD) referred to stress myocardial perfusion single-photon emission computed tomography (MPS). Methods A total of 950 consecutive patients with suspected or known CAD were submitted by referring physicians to stress MPS for assessment of myocardial ischemia between January 2018 and June 2019. All patients underwent stress-optional rest MPS. Perfusion defects were quantitated as % of LV myocardium and expressed as total perfusion defect (TPD), representing the defect extent and severity. A TPD ≥ 5% was considered abnormal. Results During a mean follow-up of 27 months (range 4–38) 31 events occurred. Moreover, 55 (6%) patients had a COVID-19 infection. The median time from index MPS to COVID-19 infection was 16 months (range 6–24). At Cox multivariable analysis, abnormal MPS and COVID-19 infection resulted as independent predictors of events. There were no significant differences in annualized event rate in COVID-19 patients with or without abnormal MPS (p = 0.56). Differently, in patients without COVID-19 the presence of abnormal MPS was associated with higher event rate (p

Background Chronotropic incompetence is common in patients with cardiovascular disease and is associated with increased risk of adverse events. We assessed the incremental prognostic value of heart rate reserve (HRR) over stress myocardial perfusion single-photon emission computed tomography (MPS) findings in patients with suspected coronary artery disease (CAD). Methods We studied 866 patients with suspected CAD undergoing exercise stress-MPS as part of their diagnostic program. The primary study endpoint was all-cause mortality. All patients were followed for at least 5 years. HRR was calculated as the difference between peak exercise and resting HR, divided by the difference of age-predicted maximal and resting HR and expressed as percentage. Results During 7 years follow-up, 61 deaths occurred, with a 7% cumulative event rate. Patients experiencing death were older (P < .001), and had a higher prevalence of male gender (P < .001) and diabetes (P < .05). Patients with event also had lower values of HRR (65% ± 27% vs 73% ± 18%, P < .0001) and higher prevalence of stress-induced myocardial ischemia (25% vs 8%, P < .0001). Male gender, HRR and stress-induced ischemia were independent predictors of all-cause mortality (all P < .01). HRR improved the prognostic power of a model including clinical data and MPS findings, increasing the global χ2 from 66 to 82 (P < .005). Conclusions Chronotropic incompetence has independent and incremental prognostic value in predicting all-cause mortality in patients with suspected CAD undergoing exercise stress-MPS. Hence, the evaluation of HRR may further improve patients’ risk stratification.

Purpose The identification of coronary vascular dysfunction may enhance risk stratification in patients with resistant hypertension (RH). We evaluated if impaired coronary vascular function, assessed by rubidium-82 (82Rb) positron emission tomography/computed tomography (PET/CT) imaging, is associated with increased cardiovascular risk in patients with hypertension without overt coronary artery disease (CAD). Methods We studied 517 hypertensive subjects, 26% with RH, without overt CAD, and with normal stress-rest myocardial perfusion imaging at 82Rb PET/CT. The outcome end points were cardiac death, nonfatal myocardial infarction, coronary revascularization, and admission for heart failure. Results Over a median of 38 months (interquartile range 26 to 50), 21 cardiac events (4.1% cumulative event rate) occurred. Patients with RH were older (p p p p Conclusion The findings suggest that the assessment of coronary vascular function may enhance risk stratification in patients with hypertension.

Purpose. In pediatric patients with differentiated thyroid cancer (DTC), the risk of recurrence is high and the indication for postoperative 131I administration is still debated. The aim of this study was to assess the outcome in low and intermediate risk pediatric DTC patients. Methods. We retrospectively evaluated 45 pediatric patients with low or intermediate risk DTC, treated with surgery and 131I between 1992 and 2002 and with no detectable antithyroglobulin (Tg) antibodies. Follow-up was performed every 6–12 months with Tg blood level determination and imaging procedures. Results. During follow-up (64 ± 53 months), 15 events occurred (33% cumulative event rate, with an annual event rate of 5% person years). Five of these patients were submitted to additional surgery and all these 15 patients underwent a second 131I treatment course. All patients were alive at the end of the follow-up. Structural persistent disease occurred more frequently in patients at intermediate risk (p 10 ng/ml before 131I therapy (p 10 ng/ml was an independent predictor of persistent disease. Conclusions. In pediatric patients with DTC, postoperative high stimulated Tg values (>10 ng/ml) should be taken into account for deciding the extent of both initial treatment and follow-up.

Background. We performed a meta- a meta-analysis to evaluate the prognostic value of coronary flow reserve (CFR) assessed by cardiac positron emission tomography (PET) imaging in patients with suspected or known coronary artery disease (CAD). Methods. Studies published until April 2019 were identified by database search. We included studies if they evaluated CFR by PET providing data on adjusted hazard ratio (HR) for the occurrence of adverse events. Annualized event rates were calculated and the incidence rate ratios (IRR) with 95% confidence interval (CI) were estimated to compare patients with impaired and preserved CFR. Results. We identified 13 eligible articles including 11,867 patients with a follow-up ranging from 0.6 to 7.1 years. The HR for the occurrence of major adverse cardiac events (MACE) was reported in 11 studies and pooled HR was 1.93 (95% CI 1.65-2.27). The HR for the occurrence of hard events was reported in 5 studies and pooled HR was 3.11 (95% CI 1.88-5.14). Six studies reported data useful to calculate separately the incidence rate of MACE in patients with preserved and impaired CFR and pooled IRR was 2.26 (CI 95% 1.79-2.85). Three studies reported data useful to calculate separately the incidence rate of hard events in patients with preserved and impaired CFR and pooled IRR was 4.12 (CI 95% 3.08-5.51). At meta-regression analysis we found an association between HR for MACE and gender, diabetes and hypertension, while no significant association was found between HR for hard events and demographic and clinical variables. Conclusions. In patients with suspected or known CAD an impaired CFR is associated with adverse cardiovascular events. However, the large heterogeneity in study population underlines the need for further investigations to maximize the prognostic role of CFR.

We assessed the prognostic value of structural abnormalities and coronary vasodilator function in diabetic patients referred to a PET/CT for suspected coronary artery disease (CAD).We studied 451 diabetics and 451 nondiabetics without overt CAD and normal myocardial perfusion. Myocardial blood flow (MBF) was computed from the dynamic rest and stress imaging. Myocardial flow reserve (MFR) was defined as ratio of hyperemic to baseline MBF and was considered reduced when 2.During a mean follow-up of 44 months 33 events occurred. Annualized event rate (AER) was higher in diabetic than nondiabetic patients (1.4% vs 0.3%, P .001). Diabetic patients with reduced MFR had higher AER compared to those with preserved MFR (3.3% vs 0.4%, P .001). At Cox analysis, age, BMI and reduced MFR were independent predictors of events in diabetic patients. Patients with diabetes and reduced MFR had lower event-free survival compared to nondiabetic patients and MFR 2 (P .001). Event-free survival was similar in patients with diabetes and normal MFR and those without diabetes and reduced MFR.Diabetic patients with reduced MFR had higher AER and lower event-free survival compared to those with preserved MFR and to nondiabetic patients.Se evaluó el valor pronóstico de las alteraciones estructurales y la función vasodilatadora coronaria en pacientes diabéticos remitidos a PET/CT por sospecha de enfermedad arterial coronaria (EAC). MéTODOS: Se estudiaron a 451 diabéticos y 451 no diabéticos sin EAC manifiesta y perfusión miocárdica normal. Se calculó el flujo sanguíneo miocárdico (MBF) a partir de las imágenes dinámicas en reposo y estrés. La reserva de flujo miocárdico (MFR) se definió como la relación entre la MBF en hiperemia entre el basal y se consideró reducida al ser2.Durante un seguimiento promedio de 44 meses ocurrieron 33 eventos. La tasa anual de eventos (TAE) fue mayor en los pacientes diabéticos que en los no diabéticos (1.4% frente a 0.3%, P.001). Los pacientes diabéticos con MFR reducido tuvieron una TAE más alta en comparación con aquellos con MFR preservado (3.3% vs 0.4%, P. 001). En el análisis de Cox, la edad, el IMC y el MFR reducido fueron predictores independientes de eventos en pacientes diabéticos. Los pacientes con diabetes y MFR reducido tuvieron una supervivencia libre de eventos más baja en comparación con los pacientes no diabéticos y MFR2 (P. 001). La supervivencia libre de eventos fue similar en pacientes con diabetes y MFR normal y aquellos sin diabetes y MFR reducido.Los pacientes diabéticos con MFR reducido tuvieron una mayor TAE y una menor supervivencia libre de eventos en comparación con aquellos con MFR conservado y con los pacientes no diabéticos.背景:Nous avons évalué la valeur pronostique des anomalies structurelles et de la vasodilatation coronaire chez les patients diabétiques qui nous ont été envoyé pour un examen TEP/TDM pour suspicion de maladie artérielle coronaire (MAC). MéTHODES: Nous avons étudié 451 diabétiques et 451 non-diabétiques sans MAC manifeste et avec une perfusion myocardique normale. Le débit sanguin myocardique (DSM) a été calculé sur bases des images TEP/TDM de repos et de stress. La réserve de perfusion myocardique (RPM) a été définie comme le rapport entre l’hyperémie myocardique et la perfusion myocardique de base et a été considérée comme réduite avec un rapport inferieur à 2. RéSULTATS: Au cours d’un suivi moyen de 44 mois, 33 événements cardiaques ont été enregistrés. Le nombre d’événements cardiaques annualisés (ECA) s’est avéré plus élevé chez les patients diabétiques que chez les patients non diabétiques (1,4% vs 0,3%, P0,001). Les patients diabétiques dont la RPM était réduite ont montré un nombre d’ECA plus élevé que ceux dont la RPM était préservée (3,3% vs 0,4%, P0,001). L’analyse statistique basée sur la méthode Cox a montré que, l’âge, l’IMC et la réduction de la RPM sont des paramètres indépendants chez les patients diabétiques. Les patients atteints de diabète avec une réduction de leur RPM ont eu une survie avec un nombre plus élevés d’événements cardiaques par rapport aux patients non diabétiques avec une RPM inferieure à 2 (P.001). La survie sans événements cardiaques s’est révélée similaire chez les patients atteints de diabète avec une RPM normale et ceux sans diabète avec une RPM réduite.Dans cette étude, les patients diabétiques avec un MFR réduit ont eu une survie entachée d’un nombre plus important d’événements cardiaques par rapport aux diabétiques avec une réserve de perfusion myocardique préservée et aux patients non diabétiques.

Aims Cardiac imaging with positron emission tomography/computed tomography (PET/CT) allows measurement of coronary artery calcium (CAC), stress-induced myocardial ischemia and myocardial perfusion reserve (MPR). We evaluated the prognostic role of the combined assessment of regional CAC score, ischemic total perfusion defect (ITPD) and MPR in predicting lesion-related outcome in patients with suspected coronary artery disease (CAD). Methods and results We studied 206 patients with suspected CAD referred to 82Rb PET/CT cardiac imaging and available coronary angiographic data. The outcome end points were cardiac death, target vessel-related myocardial infarction or unstable angina requiring coronary revascularization. Compared to vessels without event, those with event showed higher CAC score and ITPD, and lower hyperemic myocardial blood flow and MPR (all P

Cardiac amyloidosis is a restrictive infiltrative cardiomyopathy burdened by high mortality. The two more common forms are immunoglobulin light-chain amyloidosis and transthyretin-related amyloidosis with different prognoses and treatments. However, distinguishing between them is challenging. Appropriate utilization of the different available imaging techniques in the evaluation of patients with known or suspected cardiac amyloidosis is mandatory. We report two cases with cardiac amyloidosis of different etiology and with distinct imaging patterns. In the first case, the negative 99mTc-diphosphonate imaging was useful to support the diagnosis of cardiac amyloid light-chain; the second case emphasized the utility of whole-body scintigraphy in recognizing transthyretin-related cardiac amyloidosis and the potential role of cadmium-zinc-telluride SPECT imaging for the evaluation of segmental distribution of cardiac disease. Both cases support the growing interest in looking for noninvasive methods to type cardiac amyloidosis in the place of invasive myocardial biopsy highlighting both possibilities and limitations of available imaging techniques in diagnosis and treatment monitoring.

BACKGROUND: We compared the long-term prognostic value of coronary artery calcium (CAC) scanning, coronary computed tomographic angiography (CCTA), and stress single-photon emission computed tomography myocardial perfusion imaging (MPI) in patients with suspected coronary artery disease (CAD). METHODS AND RESULTS: A total of 164 patients were studied. CAC score was measured according to the Agatston method and patients were categorized into 3 groups (0, 1-300, and >300). The following events were recorded: cardiac death, nonfatal infarction, and unstable angina requiring revascularization. Follow-up was 95% complete during a mean period of 82 ± 34 months. During follow-up, 22 events occurred (14% cumulative event rate). Event-free survival decreased with worsening of CAC score category (P < .001) and it was worse (P < .001) in patients with significant CAD (≥50% stenosis) and in those with stress-induced ischemia (summed difference score >2). At multivariable analysis, CAC (P = .001) and ischemia (P = .012) were independent predictors of events. MPI data added prognostic information to a model including clinical variables, CAC and CCTA findings, increasing the global Chi-square from 36.2 to 41.9 (P = .013). The decision curve analyses in patients with CAC score >0 indicate that the prognostic model including MPI resulted in a higher net benefit across a wide range of decision threshold probabilities. CONCLUSIONS: CAC and MPI, but not CCTA, are independent predictors of cardiac events. Stress MPI appears to improve risk stratification over clinical variables, CAC scanning and CCTA findings.

Background: In patients with differentiated thyroid cancer (DTC) and raising serum thyroglobulin (Tg) after total or near-total thyroidectomy and 131I remnant ablation an empiric 131I therapy may be considered. However, outcome data after empiric therapy in did not show a clear evidence of improved survival. We assessed the efficacy of such empiric 131I therapy in patients with DTC and evaluated the long-term outcome.Methods: A total of 100 patients with DTC showing raised Tg level during follow-up after thyroidectomy and 131I ablation were treated with a further 131I therapy (6.1 ± 1.7 GBq). Whole-body scan (WBS) was performed 5–7 days after therapy. Tg value at 12 months after 131I therapy was considered as an indicator of treatment response: ≤1.5 ng/ml complete remission (CR), >50% decrease partial remission (PR), higher than pre-therapy progression disease (PD), all other cases stable disease (SD). Patients were followed-up for 96 ± 75 months.Results: After 12 months, 62% of patients were in CR, 16% in PR, 8% in SD, and 14% in PD. WBS was positive in 41% of patients and negative in 59% (P = NS). Among patients with local recurrences at WBS 89% showed either CR or PR, while 71% of patients with distant metastases were in SD or PD (P < 0.001). Distant metastases at WBS (P < 0.05), CR (P < 0.0001), and CR + PR (P < 0.0001) were predictors of both progression free survival and overall survival.Conclusion: There is a beneficial effect of 131I therapy on outcome of patients with DTC treated on the basis of elevated Tg value. In these patients, survival is affected by achievement of CR or PR at 12 months evaluation after 131I therapy and by the presence of distant metastases at WBS.

Background. A normal stress myocardial perfusion single-photon emission computed tomography (MPS) is associated with a good clinical outcome. New iterative algorithms, such as wide beam reconstruction (WBR), that improve image interpretation with half dose or half time acquisition have been proposed for cardiac MPS. The aim of this study was to assess the long-term predictive value of a low dose normal stress-only MPS with WBR using conventional Anger camera in patients with known or suspected coronary artery disease (CAD). Methods and Results. A total of 2106 patients with known or suspected CAD and normal perfusion at half dose protocol stress only MPS protocol were followed for a mean of 6.6 ± 2.7 years. MPS data were reconstructed with WBR iterative algorithm. End-point events were cardiac death or nonfatal myocardial infarction. Non-cardiac death was considered the competing event. During follow-up, 149 cardiac events occurred with an annualized event rate of 1.2%. Independent predictors of cardiac events at Cox analysis were age, male gender, diabetes mellitus, previous myocardial infarction and the need for pharmacological stress testing. At Fine-Gray analysis the cumulative incidence of cardiac events progressively increases with age and in the presence of diabetes for any combination of gender and stress type. Survival tree analysis confirmed that long-term prognosis considerably varies according of risk factors profile. Conclusions. Low dose normal stress-only WBR MPS has a reliable long-term prognostic value in patients with suspected or known CAD. This finding supports the introduction of such a method into clinical practice with a consistent dose optimization in the interest of patients and exposed staff.

PURPOSE: To evaluate the prognostic value of coronary atherosclerotic burden, assessed by coronary artery calcium (CAC) score, and coronary vascular function, assessed by coronary flow reserve (CFR) in patients with suspected coronary artery disease (CAD). METHODS: We studied 436 patients undergoing hybrid 82Rb positron emission tomography/computed tomography imaging. CAC score was measured according to the Agatston method, and patients were categorized into three groups (0

Treadmill exercise electrocardiogram (ECG) is one of the most commonly used noninvasive tests for the assessment of ischemic heart disease (IHD). Sex-specific challenges in diagnostic and prognostic tests methods for IHD outlined the importance of pretest probability evaluation and referral bias using risk-prediction charts available for both asymptomatic and symptomatic women. Accordingly, exercise ECG has been indicated as the initial test for the symptomatic women at intermediate risk of IHD who has a normal resting ECG and is capable of maximal exercise. However, the difficulties of using exercise testing for diagnosing IHD in women have led to an initial speculation that stress imaging may be preferred to standard stress testing. This editorial analyzed a large body of evidence on the diagnostic and prognostic powers of treadmill ECG and exercise myocardial perfusion imaging (MPI) according to new advanced imaging technologies.

PURPOSE:The aim of this study was to evaluate the role of F-FDG PET/CT performed after surgery but before radioiodine therapy in patients with differentiated thyroid cancer. PROCEDURES:FDG PET/CT was performed off l-thyroxine in 60 newly diagnosed differentiated thyroid cancer patients. Clinical and hematological evaluation as well as high-resolution neck ultrasound were performed. All patients underwent a complete follow-up (range, 6-67 months; mean [SD], 31.7 [20.6] months). The date of recurrence or the most recent office visit was recorded. Progression-free survival (PFS) is the primary end point of this study. Analysis was performed by Cox proportional hazards model. Survival curves were generated using Kaplan-Meier estimates, and the log-rank test was used to assess significance. RESULTS:FDG PET/CT was negative in 63% of patients, 20% had FDG thyroid bed uptake, 5% distant metastases, and 12% lymph node FDG uptake. In patients with positive FDG PET/CT scan (ie, those with distant metastases or lymph node uptake), a higher rate of recurrence was observed (50% vs 6%, P < 0.05). Thyroglobulin, neck ultrasound, stage, and FDG PET/CT correlated with PFS at univariate analysis. At multivariate analysis, only thyroglobulin and FDG PET/CT continued to be predictors of PFS. Patients with a negative FDG PET/CT scan have a better PFS either in the whole group or in those with elevated thyroglobulin level (both >2 ng/mL and >10 ng/mL). CONCLUSIONS:FDG PET/CT was abnormal in 17% of patients. Moreover, FDG PET/CT has an independent prognostic role, with a better PFS in patients with a negative scan.

Purpose: Reversible ischaemia at radionuclide myocardial perfusion imaging (MPI) accurately predicts risk of cardiac death and nonfatal myocardial infarction (major adverse cardiac events, MACE). This prognostic penetrance might be empowered by accounting for exercise tolerance as an indirect index of ischaemia severity. The present study aimed to verify this hypothesis integrating imaging assessment of ischaemia severity with exercise maximal rate pressure product (RPP) in a large cohort of patients with suspected or known coronary artery disease (CAD).,Methods and results: We analysed 1,502 consecutive patients (1,014 men aged 59 ± 10 years) submitted to exercise stress/rest MPI. To account for exercise tolerance, the summed difference score (SDS) was divided by RPP at tracer injection providing a clinical prognostic index (CPI). Reversible ischaemia was documented in 357 patients (24 %) and was classified by SDS as mild (SDS 2-4) in 180, moderate (SDS 5-7) in 118 and severe (SDS >7) in 59. CPI values of ischaemic patients were clustered into tertiles with lowest and highest values indicating low and high risk, respectively. CPI modified SDS risk prediction in 119/357 (33 %) patients. During a 60-month follow-up, MACE occurred in 68 patients. Kaplan-Meier analysis revealed that CPI significantly improved predictive power for MACE incidence with respect to SDS alone. Multivariate Cox analysis confirmed the additive independent value of CPI-derived information.,Conclusion: Integration of ischaemic threshold and ischaemia extension and severity can improve accuracy of exercise MPI in predicting long-term outcome in a large cohort of patients with suspected or known CAD.