Cardiac sarcoidosis is a potentially fatal complication of sarcoidosis. The 1993 guidelines of the Ministry of Health, Labour, and Welfare (MHLW) of Japan have been used as the diagnostic gold standard and for comparison with imaging modalities. 18 F-FDG PET is not currently included in the guidelines. However, studies have shown promising data using 18 F-FDG PET. We conducted a systematic review of studies that evaluated the accuracy of 18 F-FDG PET for the diagnosis of cardiac sarcoidosis compared with MHLW guidelines. Data from a prospective Ontario provincial registry are also reported and included in the metaanalysis. Methods: PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for studies that satisfied predetermined criteria. Quality evaluation using the Quality Assessment for Diagnostic Accuracy Studies was performed by 2 independent masked observers. Data were extracted and analyzed to measure study-specific and pooled accuracy for 18 F-FDG PET compared with the MHLW as the reference. Results: A total of 519 titles was identified; 7 studies, including the Ontario registry, were selected for inclusion. Metaanalysis of these 7 studies was conducted, with a total of 164 patients, most of whom had been diagnosed with systemic sarcoidosis. The prevalence of cardiac sarcoidosis was 50% in the whole population. Pooled estimates for 18 F-FDG PET yielded 89% sensitivity (95% confidence interval [CI], 79%-96%), 78% specificity (95% CI, 68%-86%), a 4.1 positive likelihood ratio (95% CI, 1.7-10), and a 0.19 negative likelihood ratio (95% CI, 0.1-0.4). The overall diagnostic odds ratio was 25.6 (95% CI, 7.3-89.5), and the area under the summary receiver operator characteristic curve was 93% 6 3.5. The Ontario study yielded sensitivity and specificity of 79% and 70%, respectively. Conclusion: The high diagnostic accuracy determined for 18 F-FDG PET in this metaanalysis suggests potential value for diagnosis of cardiac sarcoidosis compared with the MHLW guidelines. These results may affect patient care by providing supportive evidence for more effective use of 18 F-FDG PET in the diagnosis of cardiac sarcoidosis.Large-scale multicenter studies are required to further evaluate this role.

The PVs and PLA demonstrate unique activation and repolarization characteristics in response to autonomic manipulation. The heterogeneity of vagal responses correlates with the pattern of IKAch distribution in the LA. The peculiar autonomic characteristics of the PVs and PLA might create substrate for re-entry and AF.

Quantifying CAC using ACCT images appears to be feasible and accurate. In a single cardiac PET examination, information regarding perfusion, LV function, flow quantification, and CAC can be obtained without additional radiation.

A normal database containing the relative perfusion scores of patients with LLK of CAD can be used to accurately diagnose obstructive coronary disease using low-dose Rb-82 with 3D PET-CT imaging.

Quantification of CAC from a single contrast-enhanced CCTA scan is feasible and correlates well with Standard-CAC. Larger, multicentre studies are needed to validate the universal applicability of CAC quantified using CCTA.

Rubidium-ARMI ( 82 Rb as an Alternative Radiopharmaceutical for Myocardial Imaging) is a multicenter trial to evaluate the accuracy, outcomes, and cost-effectiveness of low-dose 82 Rb perfusion imaging using 3-dimensional (3D) PET/CT technology. Standardized imaging protocols are essential to ensure consistent interpretation. Methods: Cardiac phantom qualifying scans were obtained at 7 recruiting centers. Low-dose (10 MBq/kg) rest and pharmacologic stress 82 Rb PET scans were obtained in 25 patients at each site. Summed stress scores, summed rest scores, and summed difference scores (SSS, SRS, and SDS [respectively] 5 SSS-SRS) were evaluated using 17-segment visual interpretation with a discretized color map. All scans were coread at the core lab (University of Ottawa Heart Institute) to assess agreement of scoring, clinical diagnosis, and image quality. Scoring differences greater than 3 underwent a third review to improve consensus. Scoring agreement was evaluated with intraclass correlation coefficient (ICC-r), concordance of clinical interpretation, and image quality using k coefficient and percentage agreement. Patient 99m Tc and 201 Tl SPECT scans (n 5 25) from 2 centers were analyzed similarly for comparison to 82 Rb. Results: Qualifying scores of SSS 5 2, SDS 5 2, were achieved uniformly at all imaging sites on 9 different 3D PET/CT scanners. Patient scores showed good agreement between core and recruiting sites: ICC-r 5 0.92, 0.77 for SSS, SDS. Eighty-five and eighty-seven percent of SSS and SDS scores, respectively, had site-core differences of 3 or less. After consensus review, scoring agreement improved to ICC-r 5 0.97, 0.96 for SSS, SDS (P , 0.05). The agreement of normal versus abnormal (SSS $ 4) and nonischemic versus ischemic (SDS $ 2) studies was excellent: ICC-r 5 0.90 and 0.88. Overall interpretation showed excellent agreement, with a k 5 0.94. Image quality was perceived differently by the site versus core reviewers (90% vs. 76% good or better; P , 0.05). By comparison, scoring agreement of the SPECT scans was ICC-r 5 0.82, 0.72 for SSS, SDS. Seventy-six and eighty-eight percent of SSS and SDS scores, respectively, had site-core differences of 3 or less. Consensus review again improved scoring agreement to ICC-r 5 0.97, 0.90 for SSS, SDS (P , 0.05). Conclusion: 82 Rb myocardial perfusion imaging protocols were implemented with highly repeatable interpretation in centers using 3D PET/CT technology, through an effective standardization and quality assurance program. Site scoring of 82 Rb PET myocardial perfusion imaging scans was found to be in good agreement with core lab standards, suggesting that the data from these centers may be combined for analysis of the rubidium-ARMI endpoints.

Coronary artery disease is the major cause of heart failure in North America. Viability assessment is important as it aims to identify patients who stand to benefit from coronary revascularization. Radionuclide modalities currently used in the assessment of viability include 201Tl SPECT, 99mTc-based SPECT imaging, and 18F-fluorodexoyglucose (18F-FDG)-PET imaging. Different advances have been made in the last year to improve the sensitivity and specificity of these modalities. In addition, the optimum amount of viable (yet dysfunctional) myocardium is important to identify in patients, as a risk–benefit ratio must be considered. Patients with predominantly viable/hibernating myocardium can benefit from revascularization from a mortality and morbidity standpoint. However, in patients with minimal viability (predominantly scarred myocardium), revascularization risk may certainly be too high to justify revascularization without expected benefit. Understanding different radionuclide modalities and new developments in the assessment of viability in ischemic heart failure patients is the focus of this discussion.

Highlights Visually estimated coronary artery calcium was an independent predictor of MACE. VECAC provides complementary anatomic information with other SPECT-MPI markers. Physicians should consider routinely evaluating and reporting VECACS.