The utility of beta-hydroxybutyrate in detecting myocardial glucose uptake suppression in patients undergoing inflammatory [18F]-FDG PET studies.

PURPOSE: We evaluated whether serum beta-hydroxybutyrate (BHB) can identify adequate suppression of the left ventricle (LV) among patients undergoing [18F]-fluorodeoxyglucose positron emission tomography ([18F]-FDG PET) for cardiac inflammatory/infectious studies. METHODS: Consecutive patients who underwent [18F]-FDG PET imaging were included. Serum BHB levels were measured in all patients on the day of imaging prior to injecting [18F]-FDG. Myocardial [18F]-FDG suppression was defined if [18F]-FDG uptake in the walls of myocardium, measured using standardized uptake values (SUV), was lower than the blood pool. The optimal threshold of BHB to identify myocardial suppression was based on receiver operating characteristics (ROC) in a random 30% sample of the study population (derivation cohort) and tested in the remaining 70% of sample (validation cohort). RESULTS: A total of 256 images from 220 patients were included. Patients with sufficient LV suppression had significantly higher BHB levels compared to those with non-suppressed myocardium (median (IQR) BHB 0.6 (0.3-0.8) vs. 0.2 (0.2-0.3) mmol/l, p < 0.001, respectively). BHB level ≥ 0.335 mmol/l had a sensitivity of 84.90% and a specificity of 92.60% to identify adequate LV suppression in the validation cohort. All patients (100%) with BHB ≥ 0.41 mmol/l had adequate myocardial suppression compared to 29.63% of patients with BHB ≤ 0.20 mmol/l. CONCLUSION: Serum BHB level can be used at the point of care to identify sufficient LV suppression in patients undergoing [18F]-FDG PET cardiac inflammatory/infectious studies. Central illustration (image to the right) shows representative cases of patient images and BHB and, in the image to the left, shows the sensitivity and specificity to identify left myocardial suppression using BHB in validation group.

Diagnosis of cardiac sarcoidosis: a primer for non-imagers.

Sarcoidosis is a multisystem granulomatous disorder that can potentially involve any organ. Cardiac involvement in sarcoidosis has been reported in up to 25% of patients based on autopsy and imaging studies. The gold standard for diagnosing cardiac sarcoidosis is endomyocardial biopsy demonstrating non-caseating granulomas; however, this technique lacks sensitivity due to the patchy nature of myocardial involvement. This, along with the non-specific clinical presentation, renders the diagnosis of cardiac sarcoidosis extremely challenging. Difficulties in obtaining histopathologic diagnosis and the advances in imaging modalities have led to a paradigm shift toward non-invasive imaging in the diagnosis of cardiac sarcoidosis. Advances in cardiac imaging modalities have also allowed unprecedented insights into the prevalence and natural history of cardiac sarcoidosis. This review discusses the role of non-invasive imaging for diagnosis, risk stratification, and monitoring the response to therapies in cardiac sarcoidosis. Echocardiography remains the first-line modality due to widespread availability and affordability. Cardiac magnetic resonance imaging (CMR) can be used to study cardiac structure, function, and most importantly tissue characterization to detect inflammation and fibrosis. Fluoro-deoxy glucose positron emission tomography (FDG PET) is the gold standard for non-invasive detection of cardiac inflammation, and it offers the unique ability to assess response to therapeutic interventions. Hybrid imaging is a promising technique that allows us to combine the unique strengths of CMR and FDG PET. Understanding the advantages and disadvantages of each of these imaging modalities is crucial in order to tailor the diagnostic algorithm and utilize the most appropriate modality for each patient.

Left ventricular mass on positron emission tomography: Validation against cardiovascular magnetic resonance.

BACKGROUND: Left ventricular hypertrophy (LVH) is an important clinical finding that is independently associated with mortality and cardiovascular events. We aimed to assess the interstudy variability of LV mass quantitation between PET and CMR. METHODS: Patients who underwent both PET and CMR within 1 year were identified from prospective institutional registries. LV mass on PET was compared against LV mass on CMR using several statistical measures of agreement. RESULTS: A total of 105 patients (mean age 60 ± 14 years, 67.6% male) were included. The median (interquartile range, IQR) duration between CMR and PET was 47 (11-154) days. The median (IQR) LV mass values were 168.0 g (126.0-202.0) on CMR and 174.0 g (150.0-212.0) with PET (absolute mean difference 29.42 ± 25.3). There was a good correlation (Spearman ρ = 0.81, P < 0.001; Intraclass Correlation Coefficient 0.78, 95% CI 0.70-0.85, P < 0.001) with moderate limits of agreement (95% limits of agreement - 63.78 to 83.7.) Results were consistent, albeit with moderate correlation, in subgroups of patients with LVH, in patients with myocardial infarction, in patients with LV ejection fraction < 50%, and those with limited image quality. LV mass on PET tended to be underestimated at high values compared to CMR. CONCLUSION: We demonstrate good correlation and reproducibility of LV mass quantitation by PET against the reference standard of CMR across a wide range of normal and diseased hearts with a tendency of PET to underestimate mass at higher mass values.

Diagnostic Accuracy of FDG PET for the Identification of Vascular Graft Infection.

BACKGROUND: Fluorodeoxyglucose (FDG) positron emission tomography (FDG PET/CT) can be used to identify and localize infection in patients with vascular graft infections (VGI). We aimed to evaluate the diagnostic accuracy of 18F-FDG PET/CT by defining thresholds for standardized uptake value (SUV) and tissue-to-background ratio (TBR) that would accurately identify the presence of vascular graft infection. METHODS: Patients with suspected VGI were prospectively recruited and underwent 18F-FDG PET/CT scans. Diagnosis was based on clinical, laboratory and radiologic findings, and blinded to the results of the PET/CT scan. Receiver operator characteristics (ROC) curve analysis was done to determine optimal thresholds for SUV and TBR. RESULTS: Our final cohort consisted of 28 patients with suspected VGI (mean ± SD age 67 ± 10 years, 61% men), of which 15 patients (54%) had definitive VGI. The cohort included 61% prosthetics grafts and 39% stent-grafts. The type of graft included in this study were biologic (4%), Dacron (64%) and Polytetrafluoroethylene (32%). The location of the implanted grafts was aortic (54%) and peripheral arterial reconstruction (46%). The location of the peripheral graft was 77% in lower extremity and 23% in the upper extremity (arterio-venous grafts for dialysis access). Using ROC analysis, SUV max of 4.5, SUV mean of 3.7, and a TBR of 1.6 gave the best balance between sensitivity and specificity (93%/92%, 100%/92% and 93%/92%, respectively). All thresholds had an area under the curve ≥0.93 and correct reclassification rate ≥93%. CONCLUSIONS: Our data suggests that FDG PET/CT can be used to reliably and accurately diagnose VGI. The dual anatomic-physiologic information from FDG PET/CT can complement clinical diagnosis particularly in uncertain cases.

The prognostic role of cardiac positron emission tomography imaging in patients with sarcoidosis: A systematic review.

PURPOSE: Sarcoidosis is a multi-systemic inflammatory disease of unknown etiology. Cardiac sarcoidosis (CS) has been reported in as much as 25% of patients with systemic involvement. 18Fluorodeoxyglucose (FDG) positron emission tomography (PET) has a high diagnostic sensitivity/specificity in the diagnosis of CS. The aim of this review is to summarize evidence on the prognostic role of FDG PET. METHODS: Studies were identified by searching MEDLINE from inception to October 2020. Medical subject headings (MeSH) terms for sarcoidosis; cardiac and FDG PET imaging were used. Studies of any design assessing the prognostic role of FDG PET in patients with either suspected or confirmed cardiac sarcoidosis imaging done at baseline were included. Abnormal PET was defined as abnormal metabolism (presence of focal or focal-on-diffuse uptake of FDG) OR abnormal metabolism and a perfusion defect. Studies reporting any outcome measure were included. Pooled risk ratio for the composite outcome of MACE was done. RESULTS: A total of 6 studies were selected for final inclusion (515 patients, 53.4% women, 19.8% racial minorities.) Studies were institution based, retrospective in design and enrolled consecutive patients. All were observational in nature and published in English. All studies used a qualitative assessment of PET scans (abnormal FDG uptake with or without abnormal perfusion). Two studies assessed quantitative metrics (summed stress score in segments with abnormal FDG uptake, standardized uptake value and cardiac metabolic activity.) All studies reported major adverse cardiovascular events (MACE) as a composite outcome. After a mean follow up ranging from 1.4 to 4.1 years, there were a total of 105 MACE. All studies included death (either all-cause death or sudden cardiac death) and ventricular arrhythmia (ventricular tachycardia or ventricular fibrillation) as a component of MACE. Four of the six studies adjusted for several characteristics in their analysis. All four studies used left ventricular ejection fraction (LVEF). However, other adjustment variables were not consistent across studies. Five studies found a positive prognostic association with the primary outcome, two of which assessing right ventricular uptake. CONCLUSION: Although available evidence indicates FDG PET can be used in the risk stratification of patients with CS, our findings show further studies are needed to quantify the effect in this patient group.

Passive antipyretic therapy is not as effective as invasive hypothermia for maintaining normothermia after cardiac arrest.

AIM OF THE STUDY: Targeted temperature management is a class I indication in comatose patients after a cardiac arrest. While the literature has primarily focused on innovative methods to achieve target temperatures, pharmacologic therapy has received little attention. We sought to examine whether pharmacologic therapy using antipyretics is effective in maintaining normothermia in post cardiac arrest patients. MATERIALS AND METHODS: Patients ≥18 years who were resuscitated after an in-hospital or out-of-hospital cardiac arrest and admitted at our institution from January 2012 to September 2015 were retrospectively included. Patients were divided into groups based on the method of temperature control that was utilized. The primary outcome was temperature control <38 °C during the first 48 h after the cardiac arrest. RESULTS: 671 patients were identified in Group 1 (no hypothermia), 647 in Group 2 (antipyretics), 44 in Group 3 (invasive hypothermia), and 51 in Group 4 (invasive hypothermia and antipyretics). Mean patient age was 59 (SD ±15.7) years with 40.6% being female. Using Group 1 as the control arm, 57.7% of patients maintained target temperature with antipyretics alone (p < 0.001), compared to 69.3% in the control group and 82.1% in the combined hypothermia groups 3&4 (p = 0.01). Patients receiving both invasive hypothermia and antipyretics (Group 4), had the greatest mean temperature decrease of 5.2 °C. CONCLUSIONS: Among patients undergoing targeted temperature management, relying solely on as needed use of antipyretics is not sufficient to maintain temperatures <38 °C. However, antipyretics could be used as an initial strategy if given regularly and/or in conjunction with more aggressive cooling techniques.

PET/CT Myocardial Perfusion Imaging Acquisition and Processing: Ten Tips and Tricks to Help You Succeed.

PURPOSE OF REVIEW: Positron emission tomography (PET) is a leading non-invasive modality for the diagnosis of coronary artery disease due to its diagnostic accuracy and high image quality. With the latest advances in PET systems, clinicians are able to assess for myocardial ischemia and myocardial blood flow while exposing patients to extremely low radiation doses. This review will focus on the basics of acquisition and processing of hybrid PET/CT systems from appropriate patient selection to common artifacts and pitfalls. RECENT FINDINGS: The continued development of hybrid PET/CT technology is producing scanners with exquisite sensitivity capable of generating high-quality images while exposing patients to low radiation doses. List mode acquisition is an essential component in all modern PET/CT scanners allowing simultaneous dynamic and ECG-gated imaging without lengthening scan duration. Various PET radiotracers are currently being developed but rubidium-82 and 13N-ammonia remain the most commonly used perfusion radiotracers. The development of mini 13N-ammonia cyclotrons is a promising tool that should increase access to this radiotracer. Misregistration, attenuation from extra-cardiac activity, and patient motion are the most common causes of artifacts during perfusion imaging. Techniques to automatically realign images and correct respiratory or patient motion artifacts continue to evolve. Despite the continuous evolution of PET imaging techniques, basic knowledge of scan parameters, acquisition techniques, and post processing tools remains essential to ensure high-quality images are produced and artifacts are recognized and corrected. Future research should focus on optimizing scanners to allow for shorter scan protocols and lower radiation exposure as well as continue developing techniques to minimize and correct for motion and misregistration artifacts.

Real world utilization and impact of the wearable cardioverter-defibrillator in a community setting.

INTRODUCTION: The wearable cardioverter-defibrillator (WCD) is used in patients at risk for sudden cardiac death (SCD) but not immediate candidates for intracardiac defibrillator (ICD) implantation. METHODS: We performed a single center retrospective study of patients prescribed WCD upon hospital discharge from January 2002 to October 2015. Clinical characteristics were obtained from the hospital electronic database and device data from Zoll LifeVest database. RESULTS: Of 140 patients, 62% were men, 85.9% were African-American and mean age was 58.2 ± 15.5 years. Ischemic cardiomyopathy was present in 45 (32%) and non-ischemic cardiomyopathy in 64 patients (46%). Mean left ventricular ejection fraction (EF) was 0.28 ± 0.4. WCD was worn for 7657 patient-days (21 patient-years), with each patient using WCD for median of 43 days (IQR: 7-83 days), and daily mean use 17.3 ± 7.5 h. There were a total of 6 (4.2%) WCD shocks of which 2 (1.4%) were appropriate (one for VT, one for VF) and 4 (2.8%) were inappropriate (2 had supraventricular tachycardia, 2 had artifact). Two patients who received appropriate shocks were African-American with non-ischemic cardiomyopathy (EF<20%), non-sustained VT and wide QRS duration. Upon termination of WCD use, 45 (32%) received ICD while EF improved in 34 patients (32%). CONCLUSIONS: In a predominantly minority, community setting, WCD compliance is high and use is effective in aborting SCD. However, inappropriate shocks do occur. A significant proportion of patients did not ultimately require ICD implantation suggesting this may be a cost-effective strategy in patients at risk of SCD.

Comparison of traditional face-to-face teaching with synchronous e-learning in otolaryngology emergencies teaching to medical undergraduates: a randomised controlled trial.

Undergraduate otolaryngology teaching in the UK is generally limited primarily due to curriculum time constraints with traditional face-to-face (FtF) teaching being restrained by the limitations of time and location. Advances in network technology have opened up new doors for the delivery of teaching in the form of online learning. This study compares a traditional instructor-led lecture with synchronous e-learning (SeL) using otolaryngological emergencies teaching as an educational intervention. A randomised controlled trial was designed involving two groups of medical students attending an otolaryngology emergencies management lecture: one present FtF and the other viewing the streamed lecture online. The primary outcome measure was improvement between pre-and post-lecture test scores. Secondary outcomes comprised the students' ratings of the lecture on a Likert-type scale. Students in both groups had improved test scores following the lecture (p < 0.001 for both groups) and there was no difference in magnitude of improvement in test scores between the two groups (p = 0.168). There was no difference in student ratings between the two groups for the usefulness of the lecture (p = 0.484), interactivity (p = 0.834) and meeting educational needs (p = 0.968). The FtF group, however, was more satisfied overall (p = 0.034). This study demonstrates that SeL may be as effective as FtF teaching in improving students' knowledge on the management of otolaryngological emergencies, and that it is generally positively perceived by medical undergraduates. This highlights the potential utility of e-learning technology in undergraduate otolaryngology training.

Comparison of Medical Therapy, Valve Surgery, and Percutaneous Mechanical Aspiration for Tricuspid Valve Infective Endocarditis.

BACKGROUND: The opioid pandemic, and particularly injection drug use, has led to an increase in cases of tricuspid valve infective endocarditis. Indications for valve surgery in right-sided infective endocarditis are not well-defined. Percutaneous mechanical aspiration is considered an alternative in patients at high risk for re-infection of a prosthetic valve but lacks robust outcomes data. This retrospective analysis compares the primary outcome of death within 1 year for patients with isolated tricuspid valve infective endocarditis treated with medical therapy alone vs percutaneous mechanical aspiration or valve surgery. METHODS: The authors performed a retrospective cohort study of patients with isolated tricuspid valve infective endocarditis over a 10-year period. Medical record review was performed to collect demographic-and outcomes-related data. The association between treatment group and outcomes was assessed using Cox proportional hazard regression with inverse probability of treatment weighting. RESULTS: Between January 1, 2009, and December 31, 2018, 215 patients with isolated tricuspid valve infective endocarditis and surgical indications were identified. One hundred patients (46.5%) were managed medically, 49 (22.8%) were managed surgically, and 66 (30.7%) underwent percutaneous mechanical aspiration. There was no significant difference in 1-year mortality between the 3 treatment groups (P = .15). Vegetation size > 2.0 cm was associated with increased 1-year mortality (hazard ratio 3.01; P = .03). Addiction medicine consultation was associated with decreased 1-year mortality (hazard ratio 0.117; P = .0008). CONCLUSION: The study highlights that surgery or percutaneous mechanical aspiration in addition to medical therapy does not improve 1-year mortality in patients with isolated tricuspid valve infective endocarditis. Addiction medicine consultation was associated with decreased 1-year mortality in patients with injection drug use-associated isolated tricuspid valve infective endocarditis.

Post cardiac arrest left ventricular ejection fraction associated with survival to discharge.

Background: Post cardiac arrest left ventricular ejection fraction (LVEF) is routinely assessed, but the implications of this are unknown. This study aimed to assess the association between post cardiac arrest LVEF and survival to hospital discharge. Methods: In this retrospective cohort study, all in-hospital and out of hospital cardiac arrests at our tertiary care center between January 2012 and September 2015 were included. Baseline demographics, clinical data, characteristics of the arrest, and interventions performed were collected. Earliest post cardiac arrest echocardiograms were reviewed with LVEF documented. The primary outcome was survival to discharge. Results: A total of 736 patients were included in the analysis (mean age 58 years, 44% female). 15% were out of hospital cardiac arrest (24% shockable rhythm). After adjusting for covariates, patients with LVEF < 30% had 36% lower odds of surviving to hospital discharge than those with LVEF ≥ 52% (p = 0.014). Shockable initial rhythm and targeted temperature management were associated with improved survival. Conclusion: After a cardiac arrest, an initial LVEF < 30% is associated with significantly lower odds of survival to hospital discharge.

Acute drug-use-related native tricuspid valve infective endocarditis: a non-surgical disease.

As a result of the ongoing opioid epidemic, physicians have encountered increasing rates of drug-use-related native tricuspid valve infective endocarditis (DU-TVIE), a complex multi-faceted disease that is best managed by interdisciplinary teams. Despite the large number of patients with DU-TVIE, there is little data to support the optimal treatment strategy with respect to medical and surgical therapy. The recent introduction of percutaneous mechanical aspiration of tricuspid valve vegetations has added another treatment modality that is also of uncertain benefit. Here we review the literature on the management of DU-TVIE and highlight the multi-step treatment approach developed by the multidisciplinary endocarditis team at the University of Kentucky.

Beyond a team: The comprehensive interdisciplinary endocarditis program in the United States.

Although multidisciplinary teams have been shown to decrease in-hospital mortality for patient with infectious endocarditis, most studies have focused on the inpatient role of these teams, and are primarily based at European tertiary care centers. There is limited literature available on the optimal longitudinal care of this patient population. Here we outline our experience developing an interdisciplinary endocarditis program at the University of Kentucky, which cares for patients from their index hospitalization into the outpatient setting, while also coordinating transfers from regional hospitals and offering education to regional providers.

Autologous CD133 + Cells and Laser Revascularization in patients with severe Ischemic Cardiomyopathy.

OBJECTIVE: We tested the hypothesis that targeted TMLR combined with intramyocardial injection of autologous CD 133+ progenitor cells is safe and feasible in patients with chronic ischemic cardiomyopathy (ICM) and no revascularization options. METHODS: Eight male patients (age 62 ± 2.4 years) with multivessel severe ischemic heart disease and no revascularization options were enrolled. Autologous CD 133 + endothelial progenitor cells were derived and purified from the bone marrow on the day of surgery using the clinical-grade closed CliniMACS system. Using a lateral thoracotomy approach, TMLR was performed, followed by transmyocardial transplantation of purified CD133 + cells (mean number of transplanted cells: 12.5 × 106) in the region surrounding the TMLR sites. These sites were selected based on ischemia on pre-procedure perfusion imaging. We performed clinical and myocardial perfusion imaging pre-procedure and then at 6- and 12-month follow-up. RESULTS: No major complications or death occurred during the procedure or during the peri-operative hospital stay. One patient died of cardiac cause 6 months post-procedure. There was a reported short-term improvement in anginal and heart failure symptoms and a modest reduction in the ischemic score as assessed by perfusion imaging. CONCLUSIONS: Our phase 1 clinical study examining the combination therapy of targeted transmyocardial laser revascularization therapy and autologous CD133 + endothelial progenitor cells in patients with chronic ICM and no revascularization options demonstrates the feasibility and short-term safety of this combined approach and warrants future larger phase 2 randomized clinical studies.

The Evolving Trends in Infective Endocarditis and Determinants of Mortality: a 10-year Experience From a Tertiary Care Epicenter.

The epidemiology of infective endocarditis (IE) continues to evolve in areas affected by the opioid epidemic. Understanding the demographics of the disease allows us to better tailor therapy towards this at-risk population. This was an observational study of adults (age ≥ 18) admitted to the University of Kentucky hospital with IE between January 2009 and December 2018. 1,255 patients were included in the final analysis. The mean age was 42 years, 45% were female and injection drug use was seen in 66% of patients. On multivariable analysis, higher Charlson comorbidity indices, left sided, and multivalve involvement were associated with increased mortality, whereas surgical intervention demonstrated a trend towards lower mortality. Our results highlight the alarming increase in injection drug use related IE and the high mortality rates despite therapeutic advances. Patients with left sided IE, multivalve involvement and a higher Charlson comorbidity index had decreased survival.

Interoperator reliability of an on-site machine learning-based prototype to estimate CT angiography-derived fractional flow reserve.

BACKGROUND: Advances in CT and machine learning have enabled on-site non-invasive assessment of fractional flow reserve (FFRCT). PURPOSE: To assess the interoperator and intraoperator variability of coronary CT angiography-derived FFRCT using a machine learning-based postprocessing prototype. MATERIALS AND METHODS: We included 60 symptomatic patients who underwent coronary CT angiography. FFRCT was calculated by two independent operators after training using a machine learning-based on-site prototype. FFRCT was measured 1 cm distal to the coronary plaque or in the middle of the segments if no coronary lesions were present. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were used to evaluate interoperator variability effect in FFRCT estimates. Sensitivity analysis was done by cardiac risk factors, degree of stenosis and image quality. RESULTS: A total of 535 coronary segments in 60 patients were assessed. The overall ICC was 0.986 per patient (95% CI 0.977 to 0.992) and 0.972 per segment (95% CI 0.967 to 0.977). The absolute mean difference in FFRCT estimates was 0.012 per patient (95% CI for limits of agreement: -0.035 to 0.039) and 0.02 per segment (95% CI for limits of agreement: -0.077 to 0.080). Tight limits of agreement were seen on Bland-Altman analysis. Distal segments had greater variability compared with proximal/mid segments (absolute mean difference 0.011 vs 0.025, p<0.001). Results were similar on sensitivity analysis. CONCLUSION: A high degree of interoperator and intraoperator reproducibility can be achieved by on-site machine learning-based FFRCT assessment. Future research is required to evaluate the physiological relevance and prognostic value of FFRCT.

Inflammatory Cardiomyopathies: A Need to Identify Indolent Inflammation.

We present 3 cases of inflammatory cardiomyopathies illustrating the need for a multimodality imaging and multidisciplinary approach for diagnosis and treatment. (Level of Difficulty: Intermediate.).

Added Prognostic Value of Plaque Burden to Computed Tomography Angiography and Myocardial Perfusion Imaging in Patients with Diabetes.

BACKGROUND: We aimed to compare the added prognostic value of plaque burden to cardiac computed tomographic angiography (CCTA) anatomic assessment and single-photon emission computed tomography (SPECT) physiologic assessment in patients with diabetes undergoing both tests. METHODS: Consecutive patients with diabetes who underwent clinically indicated CCTA and SPECT myocardial imaging for suspected coronary artery disease were included. Stenosis severity and segment involvement score (SIS) were determined from CCTA, and presence of ischemia was determined from SPECT. Patients were followed from date of imaging for major adverse cardiovascular events (MACE). RESULTS: A total of 778 patients were included (mean age 60.6 ± 14.4 years, 55% males). After a median follow-up of 31 months, 87 (11%) patients experienced a MACE. In multivariable Cox regression models, SIS significantly predicted outcomes in models including obstructive stenosis and ischemia (hazard ratio 1.17, 95% confidence interval 1.10-1.24, P < .001; hazard ratio 1.16, 95% confidence interval 1.10-1.23, P < .001, respectively), and improved discrimination (Harrel's C 0.75, P = .006; 0.76, P = .006 in models with CCTA obstructive stenosis and SPECT ischemia, respectively). Results were consistent using subgroups of summed scores by composition of plaque (calcified vs noncalcified) and alternate definitions of obstructive stenosis. CONCLUSION: Our results suggest that in high-risk patients with diabetes and suspected coronary disease, SIS has incremental prognostic value over ischemia by SPECT or stenosis by CCTA in predicting incident cardiovascular outcomes.