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Fluorine-18 flurpiridaz is a novel positron emission tomography (PET) myocardial perfusion imaging tracer.This study sought to assess the diagnostic efficacy of flurpiridaz PET versus technetium-99m-labeled single photon emission computed tomography SPECT for the detection and evaluation of coronary artery disease (CAD), defined as ≥50% stenosis by quantitative invasive coronary angiography (ICA). Flurpiridaz safety was also evaluated.In this phase III prospective multicenter clinical study, 795 patients with known or suspected CAD from 72 clinical sites in the United States, Canada, and Finland were enrolled. A total of 755 patients were evaluable, and the mean age was 62.3 ± 9.5 years, 31% were women, 55% had body mass index ≥30 kg/mSensitivity of flurpiridaz PET (for detection of ≥50% stenosis by ICA) was 71.9% (95% confidence interval [CI]: 67.0% to 76.3%), significantly (p 0.001) higher than SPECT (53.7% [95% CI: 48.5% to 58.8%]), while specificity did not meet the prespecified noninferiority criterion (76.2% [95% CI: 71.8% to 80.1%] vs. 86.6% [95% CI: 83.2% to 89.8%]; p = NS). Receiver-operating characteristic curve analysis demonstrated superior discrimination of CAD by flurpiridaz PET versus SPECT in the overall population, in women, obese patients, and patients undergoing pharmacological stress testing (p 0.001 for all). Flurpiridaz PET was superior to SPECT for defect size (p 0.001), image quality (p 0.001), diagnostic certainty (p 0.001), and radiation exposure (6.1 ± 0.4 mSv vs. 13.4 ± 3.2 mSv; p 0.001). Flurpiridaz PET was safe and well tolerated.Flurpiridaz PET myocardial perfusion imaging shows promise as a new tracer for CAD detection and assessment of women, obese patients, and patients undergoing pharmacological stress testing. A second phase III Food and Drug Administration trial is ongoing. (A Phase 3 Multi-center Study to Assess PET Imaging of Flurpiridaz F 18 Injection in Patients with CAD; NCT01347710).

1599 Introduction: The term “spinal cord injury” (SCI) refers to damage to the spinal cord due to trauma, disease, or degeneration. According to the World Health Organization, every year approximately 500,000 people suffer from SCI, with up to 90% of these SCI cases due to trauma. The symptoms of SCI depend upon the severity of the injury and its location in the spinal cord. These symptoms may include partial or complete loss of sensory or motor function. SCI can also affect the system that regulates bowel/bladder control, breathing, heart rate and blood pressure. In this study, we explored the long-term outcomes of a moderate severity SCI in a rat model on glucose uptake throughout the spinal cord. Methods: Adult male Sprague Dawley rats were randomly divided into 2 groups. The injured group received a laminectomy at vertebral level T9 and moderate contusion SCI (150 kdyne force) was induced with Infinite Horizon Impactor (Precision Systems Incorporated, Natick, MA). Sham animals received laminectomy but no impact. PET/CT images were acquired (Siemens Inveon preclinical scanner, Erlangen, Germany) at 4 time points - baseline (prior to injury), 6 hours, 1 month and 3 months post injury for both the groups of animals. FDG uptake was assessed by drawing regions of interest (ROI’s) in the cerebellum, cervical spinal cord (C2-C5, uninjured site) and thoracic spinal cord (injured site), using Siemens Inveon Workplace software (V4.2) [Figure 1]. The Basso-Beattie-Bresnahan (BBB) scale was used to assess neurological function in both the Sham and Injured group at 1, 7, 14, 21, 28 days and 2 and 3 months [Figure 2]. The statistical analysis was done using GraphPad Prism (v8.1), mixed effect model with Sidak’s multiple comparisons tests. Results: The Sham animals showed no significant changes in glucose uptake or motor function at any time point. The Injured group showed impaired functional performance at 1 day and 1-month post injury compared to Sham group. The injured group showed decreased FDG uptake at 1- month and 3- months post injury compared to baseline, not only at the lesion site (thoracic region) but also at the uninjured site (cervical region) [Figure 3 and 4]. Interestingly, the cerebellum also showed decreased FDG uptake at 3- months’ post injury compared to baseline in the injured group of animals but not the shams [Figure 5]. The acute time point (6 hours post injury) did not show any significant alterations. Conclusions: FDG PET can be used to assess moderate spinal cord contusion in rats and indicates decreased glucose uptake up to 3 months post injury at the lesion site and in distal locations possibly suggestive of axonal degeneration. Acknowledgements: This work was supported by the Defense Health Program, Congressionally Directed Medical Research Programs through the Spinal Cord Injury Research Program under Award No. SC170244. Disclaimer: The opinions and assertions expressed herein are those of the author(s) and do not necessarily reflect the official policy or position of the Uniformed Services University or the Department of Defense.

Objectives This study compared the clinical effectiveness of pharmacologic stress myocardial perfusion imaging (MPI) plus positron emission tomography (PET) with single-photon emission computed tomography (SPECT) in patients with known coronary artery disease (CAD) presenting with symptoms suggestive of ischemia. Background Although PET MPI has been shown to have higher diagnostic accuracy in detecting hemodynamically significant CAD than SPECT MPI, whether this impacts downstream management has not been formally evaluated in randomized trials. Methods This study consisted of a single-center trial in which patients with known CAD and suspected ischemia were randomized to undergo PET or attenuation-corrected SPECT MPI between June 2009 and September 2013. Post-test management was at the discretion of the referring physician, and patients were followed for 12 months. The primary endpoint was diagnostic failure, defined as unnecessary angiography (absence of ≥50% stenosis in ≥1 vessel) or additional noninvasive testing within 60 days of the MPI. Secondary endpoints were post-test escalation of antianginal therapy, referral for angiography, coronary revascularization, and health status at 3, 6, and 12 months. Results A total of 322 patients with an evaluable MPI were randomized (n = 161 in each group). At baseline, 88.8% of patients were receiving aspirin therapy, 76.7% were taking beta-blockers, and 77.3% were taking statin therapy. Diagnostic failure within 60 days occurred in only 7 patients (2.2%) (3 [1.9%] in the PET group and 4 [2.5%] in the SPECT group; p = 0.70). There were no significant differences between the 2 groups in subsequent rates of coronary angiography, coronary revascularization, or health status at 3, 6, and 12 months of follow-up (all p values ≥0.20); however, when subjects were stratified by findings on MPI in a post hoc analysis, those with high-risk MPI on PET testing had higher rates of angiography and revascularization on follow-up than those who had SPECT MPI, whereas those undergoing low-risk PET studies had lower rates of both procedures than those undergoing SPECT (interaction between randomized modality ∗high-risk MPI for 12-month catheterization [p = 0.001] and 12-month revascularization [p = 0.09]). Conclusions In this contemporary cohort of symptomatic CAD patients who were optimally medically managed, there were no discernible differences in rates of diagnostic failure at 60 days, subsequent coronary angiography, revascularization, or patient health status at 1 year between patients evaluated by pharmacologic PET compared with those evaluated by SPECT MPI. Downstream invasive testing rates with PET MPI were more consistent with high-risk features than those with SPECT MPI. (Effectiveness Study of Single Photon Emission Computed Tomography [SPECT] Versus Positron Emission Tomography [PET] Myocardial Perfusion Imaging; NCT00976053)

Background Positron emission tomography (PET) myocardial perfusion imaging (MPI) with the novel radiopharmaceutical Fluorine-18 Flurpiridaz has been shown in Phase 1, 2, and first Phase 3 clinical studies to be safe and effective in diagnosing coronary artery disease (CAD). We describe the methodology of the second FDA-mandated phase 3 prospective, open-label, international, multi-center trial of F-18 Flurpiridaz PET MPI. Methods The primary study end point is to assess the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD [>= 50% by quantitative invasive coronary angiography (ICA)] in patients with suspected CAD. The secondary endpoints are to evaluate the diagnostic efficacy of F-18 Flurpiridaz PET MPI compared to Tc-99 m-labeled SPECT MPI in the detection of CAD in all patients and in the following subgroups: (1) females; (2) patients with body mass index >= 30 kg/m(2); and (3) diabetic patients. This trial's design differs from the first phase 3 trial in that (1) comparison to SPECT is now a secondary end point; (2) patients with known CAD are excluded; and (3) both SPECT and PET MPI are performed before ICA. Conclusions This second phase 3 study will provide additional evidence on the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD.

Positron emission tomography (PET) myocardial perfusion imaging (MPI) with the novel radiopharmaceutical Fluorine-18 Flurpiridaz has been shown in Phase 1, 2, and first Phase 3 clinical studies to be safe and effective in diagnosing coronary artery disease (CAD). We describe the methodology of the second FDA-mandated phase 3 prospective, open-label, international, multi-center trial of F-18 Flurpiridaz PET MPI.The primary study end point is to assess the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD [≥ 50% by quantitative invasive coronary angiography (ICA)] in patients with suspected CAD. The secondary endpoints are to evaluate the diagnostic efficacy of F-18 Flurpiridaz PET MPI compared to Tc-99 m-labeled SPECT MPI in the detection of CAD in all patients and in the following subgroups: (1) females; (2) patients with body mass index ≥ 30 kg/mThis second phase 3 study will provide additional evidence on the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD.NCT03354273.

Radionuclide myocardial perfusion imaging (MPI) is among the most commonly performed diagnostic tests in cardiology. Although the diagnostic and prognostic applications of radionuclide MPI are supported by a wealth of observational and clinical trial data, its performance is limited by two

Several publications and guidelines designate diabetes mellitus (DM) as a coronary artery disease (CAD) risk equivalent. The aim of this investigation was to examine DM cardiac risk equivalence from the perspective of stress SPECT myocardial perfusion imaging (MPI). We examined cardiovascular outcomes (cardiac death or nonfatal MI) of 17,499 patients referred for stress SPECT-MPI. Patients were stratified into four categories: non-DM without CAD, non-DM with CAD, DM without CAD, and DM with CAD, and normal or abnormal perfusion. Cardiac events occurred in 872 (5%), with event-free survival best among non-DM without CAD, worst in DM with CAD, and intermediate in DM without CAD, and non-DM with CAD. After multivariate adjustment, risk remained comparable between DM without CAD and non-DM with CAD [AHR 1.0 (95% CI 0.84–1.28), P =0.74]. Annualized event rates for normal subjects were 1.4% and 1.6% for non-DM with CAD and DM without CAD, respectively (P = 0.48) and 3.5% (P = 0.95) for both abnormal groups. After multivariate adjustment, outcomes were comparable within normal [AHR 1.4 (95% CI 0.98–1.96) P = 0.06] and abnormal [AHR 1.1 (95% CI 0.83–1.50) P = 0.49] MPI. Diabetic patients without CAD have comparable risk of cardiovascular events as non-diabetic patients with CAD after stratification by MPI results. These findings support diabetes as a CAD equivalent and suggest that MPI provides additional prognostic information in such patients.

This document from the American Society of Nuclear Cardiology represents an updated consensus statement on the evidence base of stress myocardial perfusion imaging (MPI), emphasizing new developments in single-photon emission tomography (SPECT) and positron emission tomography (PET) in the clinical evaluation of women presenting with symptoms of stable ischemic heart disease (SIHD). The clinical evaluation of symptomatic women is challenging due to their varying clinical presentation, clinical risk factor burden, high degree of comorbidity, and increased risk of major ischemic heart disease events. Evidence is substantial that both SPECT and PET MPI effectively risk stratify women with SIHD. The addition of coronary flow reserve (CFR) with PET improves risk detection, including for women with nonobstructive coronary artery disease and coronary microvascular dysfunction. With the advent of PET with computed tomography (CT), multiparametric imaging approaches may enable integration of MPI and CFR with CT visualization of anatomical atherosclerotic plaque to uniquely identify at-risk women. Radiation dose-reduction strategies, including the use of ultra-low-dose protocols involving stress-only imaging, solid-state detector SPECT, and PET, should be uniformly applied whenever possible to all women undergoing MPI. Appropriate candidate selection for stress MPI and for post-MPI indications for guideline-directed medical therapy and/or invasive coronary angiography are discussed in this statement. The critical need for randomized and comparative trial data in female patients is also emphasized.

The Intersocietal Accreditation Commission (IAC) began accrediting echocardiography laboratories in 1996 to improve quality in diagnostic imaging facilities. With no existing data linking accreditation to improved outcomes, the aim of this study was to examine the perceived value of accreditation among individuals who have successfully achieved IAC echocardiography accreditation. An electronic survey was sent to accredited facilities soliciting demographic data along with questions regarding the perceived value of accreditation related to 15 quality indicators; 10.455 emails were sent with 999 responses (9.6%), and 63% of respondents reported improvement in results due to accreditation. Of the 15 quality indicators, the process was perceived as leading to improvement by a majority for 10 of the quality indicators. Nonphysicians tended to report more improvement compared with physicians (64% vs. 54%, P = .056). The perceptions from hospital-based respondents were more favorable than nonhospital-based respondents (67% vs. 59%, P < .001). More than 90% of respondents reported that maintaining accreditation was important for improved quality and better reimbursement. The study showed that IAC echocardiography facility accreditation is perceived by most facilities to improve operations for most quality indicators, particularly regarding study quality and reporting.

Radiation exposure during nuclear cardiology procedures has received much attention and has prompted citations for radiation reduction. In 2010, the American Society of Nuclear Cardiology recommended reducing the average patient study radiation exposure to9 mSv in 50% of studies by 2014. Cardiac positron emission tomography (PET) for myocardial perfusion imaging (MPI) has emerged within recent years, but current radiation exposure in cardiac nuclear PET laboratories is unknown. This study evaluated current reported patient radiation exposure from nuclear laboratories in the United States applying for Intersocietal Accreditation Commission accreditation for MPI using single photon emission computed tomography (SPECT) or PET.This was an analysis of nuclear cardiology studies submitted to the Intersocietal Accreditation Commission for either or both cardiac PET and SPECT accreditation. Cardiac SPECT data represented year 2015 while PET data combined years 2013 to 2015. Data was analyzed with χRadiation exposure from cardiac PET MPI in US laboratories applying for Intersocietal Accreditation Commission accreditation is low (111 laboratories, 3.7 mSv) and substantially lower than cardiac SPECT (665 laboratories, 12.8 mSv).

Background: Radiation exposure during nuclear cardiology procedures has received much attention and has prompted citations for radiation reduction. In 2010, the American Society of Nuclear Cardiology recommended reducing the average patient study radiation exposure to Methods and Results: This was an analysis of nuclear cardiology studies submitted to the Intersocietal Accreditation Commission for either or both cardiac PET and SPECT accreditation. Cardiac SPECT data represented year 2015 while PET data combined years 2013 to 2015. Data was analyzed with χ 2 and Mann-Whitney U tests (reported as median, 25th percentile, and 75th percentile). Reported PET MPI radiation exposure for 111 laboratories (532 patient cases) was 3.7 (3.2–4.1) mSv per study with no geographic variation. Reported SPECT MPI radiation exposure for 665 laboratories (3067 patient studies) was 12.8 (12.2–14.3) mSv. Highest radiation exposure was found in the South region. Technetium-only studies resulted in a median of 12.2 mSv per study. Conclusions: Radiation exposure from cardiac PET MPI in US laboratories applying for Intersocietal Accreditation Commission accreditation is low (111 laboratories, 3.7 mSv) and substantially lower than cardiac SPECT (665 laboratories, 12.8 mSv).

The impact of baseline exercise capacity on clinical outcomes in patients with stable ischemic heart disease randomized to an initial strategy of optimal medical therapy (OMT) with or without percutaneous coronary intervention (PCI) in the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial has not been studied. A post hoc analysis was performed in 1,052 patients of COURAGE (PCI + OMT: n = 527, OMT: n = 525) who underwent exercise treadmill testing at baseline. Patients were categorized into 2 exercise capacity groups based on metabolic equivalents (METs) achieved during baseline exercise treadmill testing (

While it is well recognized that cardiac PET has the ability to accurately detect myocardial ischemia and coronary blood flow, there are multiple other novel and clinically important cardiac applications of PET which are now available for the evaluation of various disease processes of the cardiovascular system. Many of these applications utilize F18-fluorodeoxyglucose (FDG), a glucose analog which is retained within cells with a high metabolic activity and which has been used extensively in nuclear medicine to evaluate oncology patients and has recently also been used to evaluate infections. This review provides an overview of some of the clinically available novel applications, Figure 1, in cardiac PET which were discussed at the American Society of Nuclear Cardiology Cardiac PET Summit, May 12, 2014. Figure 1 Novel applications of cardiac PET.

The Intersocietal Accreditation Commission (IAC) accredits vascular, echocardiography, nuclear medicine, computed tomography, and magnetic resonance imaging laboratories. How facilities involved in the accreditation process view accreditation is unknown. The objective of this study was to examine the perception of laboratory accreditation from those who had undergone the process. An electronic survey request was sent to all facilities that had received IAC accreditation at least once. Demographic information, as well as opinions on the perceived value of accreditation as it relates to 15 quality metrics was acquired. Responses were obtained from 2782 facilities. Of the 15 quality metrics examined, the process was perceived as leading to improvements by a majority of respondents for 10 (67%) metrics including: report standardization, adherence to guidelines, test standardization, report completeness, identification of deficiencies, improved staff knowledge, report timeliness, distinguished facility, correction of deficiencies, and image quality. Overall, the perceived improvement was greater for hospital-based facilities (global 66% vs 59%; P < 0.001). Survey data demonstrate that the accreditation process has a positive perceived impact on the majority of examined metrics. These findings suggest that those undergoing the process find value in accreditation.

Many patients with suspected or known coronary artery disease (CAD) benefit from the information provided by a noninvasive cardiac imaging test. Cardiac imaging tests can provide information regarding the presence, extent, and severity of CAD, estimate risk for early and late major adverse cardiac

The Medicare Improvements for Patients and Providers Act requires accreditation for all non-hospital suppliers of nuclear cardiology, nuclear medicine, and positron emission tomography (PET) studies as a condition of reimbursement. The perceptions of these facilities regarding the value and impact of the accreditation process are unknown. We conducted an electronic survey to assess the value of nuclear cardiology accreditation. A request to participate in an electronic survey was sent to the medical and technical directors (n = 5,721) of all facilities who had received Intersocietal Accreditation Commission (IAC) Nuclear/PET accreditation. Demographic information, as well as, opinions on the value of accreditation as it relates to 16 quality metrics was obtained. There were 664 (11.6%) respondents familiar with the accreditation process of which 26% were hospital-based and 74% were nonhospital-based. Of the quality metrics examined, the process was perceived as leading to improvements by a majority of all respondents for 10 (59%) metrics including report standardization, report completeness, guideline adherence, deficiency identification, report timeliness, staff knowledge, facility distinction, deficiency correction, acquisition standardization, and image quality. Overall, the global perceived improvement was greater for hospital-based facilities (63% vs 57%; P

Previous studies have demonstrated that diabetic patients undergoing exercise stress single-photon emission-computed tomography (SPECT) myocardial perfusion imaging (MPI) have significantly lower cardiac events when compared to the diabetic patients undergoing pharmacologic stress SPECT MPI across all perfusion categories. However, there are limited data on the level of exercise achieved during exercise SPECT MPI among diabetic patients and its impact on cardiovascular outcomes.We retrospectively analyzed 14,849 consecutive patients (3,654 diabetics and 11,195 non-diabetics) undergoing exercise stress, combined exercise and pharmacologic stress, and pharmacologic stress SPECT MPI from 1996 to 2005 at a single tertiary care center. Diabetic and non-diabetic patients were categorized into 3 groups based on the metabolic equivalents (METs) achieved: ≥5 METs,5 METs, and pharmacologic stress groups. All studies were interpreted using the 17-segment ASNC model. The presence, extent, severity of perfusion defects were calculated using the summed stress score (SSS), and patients were classified into normal (SSS4), mildly abnormal (SSS 4-8), and moderate-severely abnormal (SSS8) categories. Annualized event rates (AER) for the composite end point of non-fatal myocardial infarction and cardiac death were calculated over a mean follow-up period of 2.4 ± 1.4 years with a maximum of 6 years.In moderate-severe perfusion abnormality (SSS8) category, diabetic patients who were able to achieve ≥5 METs had significantly lower AER compared to diabetic patients who were unable to achieve ≥5 METs (3% vs 5.5%, P = .04), and non-diabetic patients unable to achieve ≥5 METs (3% vs 4.8%, P.001). Diabetic patients who achieved a high workload of ≥10 METs had a very low AER of 0.9%. Diabetic patients, who attempted exercise but were unable to achieve ≥5 METs, still had significantly lower AER than diabetics undergoing pharmacologic stress MPI across all perfusion categories [1.5% vs 3.2%, P = .006 (SSS4); 2.5% vs 4.9%, P = .032 (SSS 4-8); 5.5% vs 10.3%, P = .003 (SSS8)]. After adjustment for cardiovascular risk factors, the percentage decrease in cardiac event rate for every 1-MET increment in exercise capacity was 10% in the overall cohort, 12% in diabetic group, and 8% in non-diabetic group.Despite significant perfusion defects, diabetic patients who achieve ≥5 METs during stress SPECT MPI have significantly reduced risk for future cardiac events. Diabetic patients who achieve ≥10 METs have a very low annualized event rate. These findings support that exercise capacity obtained during SPECT MPI is a surrogate for outcomes among diabetic patients undergoing nuclear stress testing.

A novel 18F-labeled ligand for the norepinephrine transporter (N-[3-bromo-4-(3-18F-fluoro-propoxy)-benzyl]-guanidine [LMI1195]) is in clinical development for mapping cardiac nerve terminals in vivo using PET. Human safety, whole-organ biodistribution, and radiation dosimetry of LMI1195 were evaluated in a phase 1 clinical trial. Methods: Twelve healthy subjects at 3 clinical sites were injected intravenously with 150–250 MBq of LMI1195. Dynamic PET images were obtained over the heart for 10 min, followed by sequential whole-body images for approximately 5 h. Blood samples were obtained, and heart rate, electrocardiogram, and blood pressure were monitored before and during imaging. Residence times were determined from multiexponential regression of organ region-of-interest data normalized by administered activity (AA). Radiation dose estimates were calculated using OLINDA/EXM. Myocardial, lung, liver, and blood-pool standardized uptake values were determined at different time intervals. Results: No adverse events due to LMI1195 were seen. Blood radioactivity cleared quickly, whereas myocardial uptake remained stable and uniform throughout the heart over 4 h. Liver and lung activity cleared relatively rapidly, providing favorable target-to-background ratios for cardiac imaging. The urinary bladder demonstrated the largest peak uptake (18.3% AA), followed by the liver (15.5% AA). The mean effective dose was 0.026 ± 0.0012 mSv/MBq. Approximately 1.6% AA was seen in the myocardium initially, remaining above 1.5% AA (decay-corrected) through 4 h after injection. The myocardium-to-liver ratio was approximately unity initially, increasing to more than 2 at 4 h. Conclusion: These preliminary data suggest that LMI1195 is well tolerated and yields a radiation dose comparable to that of other commonly used PET radiopharmaceuticals. The kinetics of myocardial and adjacent organ activity suggest that cardiac imaging should be possible with acceptable patient radiation dose.

Purpose Hospitalization in patients with systolic heart failure is associated with morbidity, mortality, and cost. Myocardial sympathetic innervation, imaged by 123I-meta-iodobenzylguanidine (123I-mIBG), has been associated with cardiac events in a recent multicenter study. The present analysis explored the relationship between 123I-mIBG imaging findings and hospitalization.

The current paper details the recommendations arising from an NIH-NHLBI/NCI-sponsored symposium held in November 2012, aiming to identify key components of a radiation accountability framework fostering patient-centered imaging and shared decision-making in cardiac imaging. Symposium participants, working in 3 tracks, identified key components of a framework to target critical radiation safety issues for the patient, the laboratory, and the larger population of patients with known or suspected cardiovascular disease. The use of ionizing radiation during an imaging procedure should be disclosed to all patients by the ordering provider at the time of ordering, and reinforced by the performing provider team. An imaging protocol with effective dose ≤3mSv is considered very low risk, not warranting extensive discussion or written informed consent. However, a protocol effective dose >20mSv was proposed as a level requiring particular attention in terms of shared decision-making and either formal discussion or written informed consent. Laboratory reporting of radiation dosimetry is a critical component of creating a quality laboratory fostering a patient-centered environment with transparent procedural methodology. Efforts should be directed to avoiding testing involving radiation, in patients with inappropriate indications. Standardized reporting and diagnostic reference levels for computed tomography and nuclear cardiology are important for the goal of public reporting of laboratory radiation dose levels in conjunction with diagnostic performance. The development of cardiac imaging technologies revolutionized cardiology practice by allowing routine, noninvasive assessment of myocardial perfusion and anatomy. It is now incumbent upon the imaging community to create an accountability framework to safely drive appropriate imaging utilization.

The above position statement originally published containing errors in the author metadata; specifically, the Expert Content Reviewers-Andrew Einstein, Raymond Russell and James R. Corbett-were tagged as full authors of the paper. The article metadata has now been corrected to remove Drs. Einstein, Russell and Corbett from the author line, and the PubMed record has been updated accordingly.

Previous data suggested that diabetic women were at greater risk for future cardiac events than diabetic men. Increasing awareness of coronary artery disease (CAD) in women and advances in the management of CAD may have changed this paradigm. To investigate gender differences in prognosis among patients with diabetes who were clinically referred for single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). Patients with diabetes undergoing SPECT-MPI from 1996 to 2006 were followed for 5 years or until cardiac death or non-fatal myocardial infarction. Clinical characteristics and nuclear parameters were compared with χ 2 and t tests. Multivariable Cox regression controlled for baseline differences and tested the impact of gender on survival. A total of 4,628 SPECT-MPI patients with diabetes (50% women, mean age 63 ± 12 years) were analyzed. There were 380 events, with rates higher in men (10% vs 7%, P

Delayed Iodine-123 meta-iodobenzylguanidine heart/mediastinum (H/M) uptake ratio predicted arrhythmic events in patients with heart failure (HF) and significant left ventricular dysfunction in ADMIRE-HF. We tested the hypothesis that resting perfusion defects on MPI-SPECT, representing scar, would further risk stratify patients beyond H/M ratio in the prediction of ventricular arrhythmic events in both ischemic (ICM) and non-ischemic cardiomyopathy (NICM) patients.Patients from the ADMIRE-HF database were classified as ICM and NICM and were stratified by delayed H/M ratio (1.6/≥1.6) and by summed rest score (SRS) (≤8/8) on MPI-SPECT. The entire cohort was also classified as high risk (H/M1.6, SRS8) and low risk (H/M ≥1.6, SRS ≤8). Scores were from visual interpretation of individual and derived consensus (average) reads per ASNC guidelines.There were 612 (66%) ICM and 317 (34%) NICM patients. ICM patients had higher mean SRS than NICM patients (25 ± 13 vs 12 ± 10). Sixty-three arrhythmic events occurred over a median follow-up of 17 months. SRS had incremental predictive value among NICM patients with low H/M ratio (1.6). There was no risk stratification in patients with ICM. Multivariable analysis for NICM with H/M ratio1.6 demonstrated SRS score8 as the only independent predictor of arrhythmic events (hazard ratio 3.3, 95% CI 1.1-9.8, P = .03). Patients classified in high-risk subgroup had statistically significant increased risk of arrhythmic events (hazard ratio 2.080, 95% CI 1.112-3.894, P = .022). There was only one event in low-risk subgroup with a trend towards lower risk of arrhythmic events (P = .07).Resting perfusion defects provide independent risk stratification in addition to Iodine-123 meta-iodobenzylguanidine sympathetic innervation imaging in predicting arrhythmic events in patients with NICM and HF. High and potentially low-risk groups for arrhythmic events can be identified based on the severity of resting perfusion defect score and H/M ratio.

It remains controversial whether the diagnostic accuracy of single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) is different in men as compared to women. We performed a meta-analysis to investigate gender differences of SPECT MPI for the diagnosis of CAD (≥50% stenosis). Two investigators independently performed a systematic review of the MEDLINE and EMBASE databases from inception through January 2012 for English-language studies determining the diagnostic accuracy of SPECT MPI. We included prospective studies that compared SPECT MPI with conventional coronary angiography which provided sufficient data to calculate gender-specific true and false positives and negatives. Data from studies evaluating

Background— Positron emission tomography (PET) myocardial perfusion imaging (MPI) offers technical benefits compared with single photon emission computed tomography (SPECT) MPI, but there has been no systematic comparison of their diagnostic accuracy for coronary artery disease. We performed a bivariate meta-analysis of the published literature to compare the sensitivity and specificity of PET versus SPECT stress MPI for ≥50% stenosis of any epicardial coronary artery in patients with known or suspected coronary artery disease. Methods and Results— We searched MEDLINE and EMBASE from inception through January 2012 and the references of identified studies for prospective, English language studies that evaluated the sensitivity and specificity of PET and/or SPECT MPI with coronary angiography as the reference standard and reported sufficient data to calculate patient-level true and false positives and negatives. Two investigators independently extracted patient and study characteristics; a third investigator resolved any disagreements. We identified 117 studies, including 108 evaluating SPECT MPI, 4 evaluating PET MPI, and 5 evaluating both modalities. Bivariate meta-analysis demonstrated a significantly higher pooled mean sensitivity with PET (92.6% [95% Confidence Interval, 88.3% to 95.5%]) compared with SPECT (88.3% [95% confidence interval, 86.4% to 90.0%]) ( P =0.035). No significant difference in specificity was observed between PET (81.3% [95% confidence interval, 66.6% to 90.4%]) and SPECT (75.8% [95% confidence interval, 72.1% to 79.1%]) ( P =0.39). Few studies investigated coronary angiography with PET. Only 5 studies directly compared SPECT and PET. Conclusions— In a meta-analysis of 11,862 patients, PET MPI demonstrated a higher sensitivity for coronary artery disease than SPECT MPI. No difference in specificity was detected in the pooled analysis of PET and SPECT MPI.

This chapter describes clinical value of cardiovascular PET imaging. This includes a detailed examination of a variety of applications, including the detection of coronary artery disease, assessment of myocardial viability and the diagnostic value for identification of cardiac sarcoidosis and infection imaging. Patient selection for Cardiovascular PET imaging procedures is also discussed, and appropriate use criteria as it applies to cardiac PET.

Maintaining a high quality laboratory in Cardiac PET requires continual evaluation and improvement. This chapter will examine methods of establishing a Quality Improvement Program in Cardiac PET including key components to the program such as instrumentation, reports, and patient care matters.

Cardiac positron emission tomographic imaging offers significant improvements in image quality over other nuclear approaches. These improvements can only be achieved with strict adherence to imaging protocols and quality control procedures. This begins with an understanding of the physics of PET, PET systems and the clinical differences of cardiac PET from other approaches. These core concepts can then be integrated into a process for reducing image artifacts, reducing radiation exposure and improving the patient care.

Objectives This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. Background Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. Methods We assessed the 90-day post-test rates of catheterization and medication changes in a prospective registry of 1,703 patients without a documented history of coronary artery disease and an intermediate to high likelihood of coronary artery disease undergoing cardiac single-photon emission computed tomography, positron emission tomography, or 64-slice coronary computed tomography angiography. Results Baseline medication use was relatively infrequent. At 90 days, 9.6% of patients underwent catheterization. The rates of catheterization and medication changes increased in proportion to test abnormality findings. Among patients with the most severe test result findings, 38% to 61% were not referred to catheterization, 20% to 30% were not receiving aspirin, 35% to 44% were not receiving a beta-blocker, and 20% to 25% were not receiving a lipid-lowering agent at 90 days after the index test. Risk-adjusted analyses revealed that compared with stress single-photon emission computed tomography or positron emission tomography, changes in aspirin and lipid-lowering agent use was greater after computed tomography angiography, as was the 90-day catheterization referral rate in the setting of normal/nonobstructive and mildly abnormal test results. Conclusions Overall, noninvasive testing had only a modest impact on clinical management of patients referred for clinical testing. Although post-imaging use of cardiac catheterization and medical therapy increased in proportion to the degree of abnormality findings, the frequency of catheterization and medication change suggests possible undertreatment of higher risk patients. Patients were more likely to undergo cardiac catheterization after computed tomography angiography than after single-photon emission computed tomography or positron emission tomography after normal/nonobstructive and mildly abnormal study findings. (Study of Perfusion and Anatomy9s Role in Coronary Artery [CAD] [SPARC]; NCT00321399)

Background: Coronary artery disease (CAD) is under-diagnosed in women. Flurpiridaz F 18 injection (flurpiridaz) is a PET myocardial perfusion imaging (MPI) tracer in clinical development. We hypothesized flurpiridaz would result in improved CAD detection in women in comparison to SPECT. Methods: This Phase 3 study was designed to assess the diagnostic efficacy of flurpiridaz and SPECT with Tc99m-labeled agents for CAD detection in the same patients. Patients with known or suspected CAD who were either scheduled for or had completed invasive coronary angiography (without intervention) were included. Each patient was studied using both rest/stress flurpiridaz PET MPI and rest/stress Tc-99m labeled SPECT MPI. Images were interpreted by 3 expert readers blinded to all clinical information. Quantitative coronary angiography (QCA) was used with patients considered CAD positive with a stenosis ≥50% in at least one major vessel. Results: 795 subjects were enrolled at 72 clinical sites in US, Canada and Finland. The study included 235 (30%) evaluable female subjects with a mean age of 62.4±10.1 years, body weight of 85.0±21.6 kg, and a BMI of 32.3±7.8 (58.7% with a BMI≥30). The agent was safe and well tolerated. A statistically significant greater sensitivity was seen for flurpiridaz (67.8%) vs SPECT (37.3%, p Conclusions: The results of this Phase 3 trial demonstrate the superiority of flurpiridaz over standard SPECT MPI for the assessment of CAD in women, with lower radiation exposure than standard SPECT.

The role of single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) in cardiac evaluation of the very elderly patients is unclear. We investigated the clinical value of SPECT MPI in very elderly patients (≥80 years) with suspected coronary artery disease (CAD) as well as in comparison to younger patients. A retrospective analysis of prospectively collected data from 8,864 patients [1,093 patients ≥80 years (very elderly), 3,369 patients 65-79 years (elderly), and 4,402 patients 50-64 years (middle-aged)] with suspected CAD who underwent exercise and/or pharmacologic stress testing with SPECT MPI between 1996 and 2005 was performed. Clinical and SPECT MPI characteristics, cardiac event rates, early (≤60 days) cardiac catheterization and revascularization rates of very elderly patients were compared to that of younger patients. Mean follow-up for cardiac events (cardiac death or non-fatal myocardial infarction) was 1.9 ± 0.9 years. Very elderly patients with moderate to severely abnormal SSS had a significantly higher annualized cardiac event rate than those with mildly abnormal or normal study (9.6% vs 3.4% and 2.5% respectively, P

Significance of electrocardiographic (ECG) changes during vasodilator stress myocardial perfusion imaging (MPI) is controversial. We examined the diagnostic and prognostic significance of ECG changes during vasodilator single photon emission computerized tomography (SPECT) MPI. We studied consecutive patients who underwent vasodilator SPECT MPI from 1995 to 2009. Patients with baseline ECG abnormalities, previous history of coronary artery bypass graft surgery or myocardial infarction (MI) were excluded. Significant coronary artery disease (CAD) was defined as >70% stenosis of any vessel or ≥50% stenosis of left main. Mean follow-up was 2.4 ± 1.5 years for cardiac events (cardiac death and non-fatal MI). Of patients in the diagnostic cohort, ST depression was associated with increased incidence of CAD with abnormal (P = .020 and P

Stress electrocardiogram(ECG)-gated single photon emission computed tomography (SPECT) imaging is highly effective in risk stratification of diabetic patients for adverse cardiac events. While patients with diabetes are predisposed to a more aggressive progression of vascular disease, the impact of its duration and type of therapy on risk stratification are unknown.From the Hartford Hospital Nuclear Cardiology clinical database, 886 diabetic patients who underwent exercise or pharmacologic stress ECG-gated SPECT were identified, with complete follow-up regarding the occurrence of adverse cardiac events and information regarding the duration of diabetes and the type of therapy (insulin vs oral medication only) at the time of testing. Images were interpreted using the American College of Cardiology/ASNC standard 17-segment scoring model.Of the 886 diabetic patients, 98 (11%) suffered cardiac death or non-fatal myocardial infarction during follow-up (2.5 ± 1.6 years). A receiver operator characteristics curve demonstrated that diabetes ≥10 years in duration provided the maximal sum of sensitivity and specificity for the prediction of adverse cardiac outcomes. Multivariate analysis identified the following as independent predictors of adverse outcome: Post-stress ejection fraction (EF)40% (P = .001), age (P = .004), insulin therapy (P = .031), diabetes duration10 years (P = .038), summed stress score (SSS)8 (P = .046). For patients with an SSS8, diabetes duration and type of therapy significantly enhanced risk stratification. Similar findings emerged for patients with a post-stress EF40%.For diabetic patients undergoing stress ECG-gated SPECT myocardial perfusion imaging, disease duration and type of therapy provide independent and incremental prognostic information. Integration of these variables with this cardiovascular imaging technology significantly enhances cardiac risk stratification.

Objectives The aim of this study was to assess the performance of β-methyl-p-[123I]-iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) to detect acute coronary syndromes (ACS) in emergency department patients with chest pain. Background Emergency department diagnosis of chest pain is problematic, often requiring prolonged observation and stress testing. BMIPP SPECT detects abnormalities in fatty acid metabolism resulting from myocardial ischemia, even many hours after symptom cessation. Methods Emergency department patients with suspected ACS were enrolled at 50 centers. Patients received 5 mCi BMIPP within 30 h of symptom cessation. BMIPP SPECT images were interpreted semiquantitatively by 3 blinded readers. Initial clinical diagnosis was based on symptoms, initial electrocardiograms, and troponin, whereas the final diagnosis was based on all available data (including angiography and stress SPECT) but not BMIPP SPECT. Final diagnoses were adjudicated by a blinded committee as ACS, intermediate likelihood of ACS, or negative for ACS. Results A total of 507 patients were studied and efficacy was evaluated in 448 patients with sufficient data. The sensitivity of BMIPP by 3 blinded readers for a final diagnosis of ACS and intermediate likelihood of ACS was 71% (95% confidence interval [CI]: 64% to 79%), 74% (95% CI: 68% to 81%), and 69% (95% CI: 62% to 77%); the corresponding specificity of BMIPP was 67% (95% CI: 61% to 73%), 54% (95% CI: 48% to 60%), and 70% (95% CI: 64% to 76%). Compared with the initial diagnosis alone, BMIPP + initial diagnosis increased sensitivity from 43% to 81% (p Conclusions The addition of BMIPP data to the initially available clinical information adds incremental value toward the early diagnosis of an ACS, potentially allowing determination of the presence or absence of ACS to be made earlier in the evaluation process. (Safety and Efficacy Iodofiltic Acid I 123 in the Treatment of Acute Coronary Syndrome [Zeus-ACS]; NCT00514501 )

Coronary artery disease (CAD) remains the leading cause of death in the United States. Due to the substantial morbidity and mortality related to CAD, stress single photon emission CT (SPECT) myocardial perfusion imaging has emerged as an important noninvasive means of evaluating patients with suspected and known CAD. The preferred stress modality is exercise. However, many patients require pharmacologic stress with vasodilators or β-agonists due to the inability to perform adequate exercise. Compared to exercise stress, pharmacologic stress is associated with more adverse effects, poorer nuclear image quality, and higher cardiac event rates. Protocols which combine pharmacologic stress with exercise improve the side effect profile of pharmacologic stress, improve image quality, and provide the clinician with objective data on functional capacity and prognosis.

Reduction of radiation exposure during nuclear cardiology procedures is a great concern. The American Society of Nuclear Cardiology (ASNC) recommends reducing radiation exposure to

The American Society of Nuclear Cardiology (ASNC) has recommended reducing the radiation exposure to