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Many lesions in patients undergoing percutaneous coronary intervention (PCI) exhibit significant calcification. Several techniques have been developed to improve outcomes in this setting. However, their impact on coronary microcirculation remains unknown. The aim of this study is to evaluate the influence of plaque modification techniques on coronary microcirculation across patients with severely calcified coronary artery disease. In this multicenter retrospective study, consecutive patients undergoing PCI with either Rotablation (RA) or Shockwave-intravascular-lithotripsy (IVL) were included. Primary endpoint was the impairment of coronary microvascular resistances assessed by Δ angiography-derived index of microvascular resistance (ΔIMRangio) which was defined as the difference in IMRangio value post- and pre-PCI. Secondary endpoints included the development of peri procedural PCI complications (flow-limiting coronary dissection, slow-flow/no reflow during PCI, coronary perforation, branch occlusion, failed PCI, stroke and shock developed during PCI) and 12-month follow-up adverse events. 162 patients were included in the analysis. Almost 80% of patients were male and the left descending anterior artery was the most common treated vessel. Both RA and IVL led to an increase in ΔIMRangio (22.3 and 10.3; p = 0.038, respectively). A significantly higher rate of PCI complications was observed in patients with ΔIMRangio above the median of the cohort (21.0% vs. 6.2%; p = 0.006). PCI with RA was independently associated with higher ΔIMRangio values (OR 2.01, 95% CI: 1.01-4.03; p = 0.048). Plaque modification with IVL and RA during PCI increases microvascular resistance. Evaluating the microcirculatory status in this setting might help to predict clinical and procedural outcomes and to optimize clinical results., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Introduction: Accurate risk stratification in patients with suspected stable coronary artery disease is essential for choosing an appropriate treatment strategy. Our aim was to develop and validate a machine learning (ML) based model to diagnose obstructive CAD (oCAD)., Method: We retrospectively have included 1007 patients without a prior history of CAD who underwent CT-based calcium scoring (CACS) and a Rubidium-82 PET scan. The entire dataset was split 4:1 into a training and test dataset. An ML model was developed on the training set using fivefold stratified cross-validation. The test dataset was used to compare the performance of expert readers to the model. The primary endpoint was oCAD on invasive coronary angiography (ICA)., Results: ROC curve analysis showed an AUC of 0.92 (95% CI 0.90-0.94) for the training dataset and 0.89 (95% CI 0.84-0.93) for the test dataset. The ML model showed no significant differences as compared to the expert readers (p ≥ 0.03) in accuracy (89% vs. 88%), sensitivity (68% vs. 69%), and specificity (92% vs. 90%)., Conclusion: The ML model resulted in a similar diagnostic performance as compared to expert readers, and may be deployed as a risk stratification tool for obstructive CAD. This study showed that utilization of ML is promising in the diagnosis of obstructive CAD., (© 2023. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

Background: Coronary flow reserve (CFR) values measured by dynamic SPECT systems are typically consistent with other modalities (e.g., PET). However, large discrepancies are often observed for individual patients. Positioning of the region-of-interest (ROI), representing the arterial input function (AIF) could explain some of these discrepancies. We explored the possibility of positioning the ROI in a manner that evaluates its consistency with patient-based injected radiotracer doses., Methods: Dose-consistent dynamic SPECT methodology was introduced, and its application was demonstrated in a twenty-patient clinical study. The effect of various ROI positions was investigated and comparison to myocardial perfusion imaging was performed., Results: Mean AIF ratios were consistent with the injected dose ratios for all examined ROI positions. Good agreement (> 80%) between total perfusion deficit and CFR was found in the detection of obstructive CAD patients for all ROIs considered. However, for individual patients, significant dependence on ROI position was observed (altering CFR by typically 30%). The proposed methodology's uncertainty was evaluated (~ 7%) and found to be smaller than the variability due to choice of ROI position., Conclusion: Dose-consistent dynamic SPECT may contribute to evaluating uncertainty of CFR measurements and may potentially decrease uncertainty by allowing improved ROI positioning for individual patients., (© 2022. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

Almost 35 years after its introduction, coronary artery calcium score (CACS) not only survived technological advances but became one of the cornerstones of contemporary cardiovascular imaging. Its simplicity and quantitative nature established it as one of the most robust approaches for atherosclerotic cardiovascular disease risk stratification in primary prevention and a powerful tool to guide therapeutic choices. Groundbreaking advances in computational models and computer power translated into a surge of artificial intelligence (AI)-based approaches directly or indirectly linked to CACS analysis. This review aims to provide essential knowledge on the AI-based techniques currently applied to CACS, setting the stage for a holistic analysis of the use of these techniques in coronary artery calcium imaging. While the focus of the review will be detailing the evidence, strengths, and limitations of end-to-end CACS algorithms in electrocardiography-gated and non-gated scans, the current role of deep-learning image reconstructions, segmentation techniques, and combined applications such as simultaneous coronary artery calcium and pulmonary nodule segmentation, will also be discussed., (© 2024. The Author(s).)

Background: Knowledge of coronary artery calcium score (CACS) influences the interpretation of myocardial perfusion imaging (MPI) with SPECT; however, the impact on PET interpretation remains unclear. We compared the added value of CACS to reporting MPI using SPECT vs PET., Methods: We retrospectively included 412 patients. 206 patients who underwent Rb-82 PET were propensity-based matched to a cohort of 4018 patients who underwent cadmium-zinc-telluride SPECT MPI to obtain a comparable group of 206 SPECT patients. Next, we created four image sets: SPECT MPI-only, PET-only, SPECT + CACS, and PET + CACS. Two physicians interpreted the 824 images as normal, equivocal, or abnormal for ischemia or irreversible defects. Additionally, event rates were compared between PET and SPECT groups during 30-month follow-up., Results: PET yielded more scans interpreted as normal than SPECT (88% vs 80%, respectively, P = 0.015). Adding CACS to SPECT increased the percentage of normal scans to 86% (P = 0.014), whereas this effect was absent for PET (90%, P = 0.77). Annualized event rates for images interpreted as normal did not differ and varied between 0.7 and 2.0% (P > 0.084)., Conclusion: Adding CACS correctly increased the percentage of normal scans for SPECT MPI but not for PET, possibly limiting the effect of adding CACS to reporting PET., (© 2021. American Society of Nuclear Cardiology.)

Purpose: CZT SPECT with the enhanced imaging characteristic facilitates SPECT myocardial blood flow (MBF) quantitation moving toward a clinical utility to uncover myocardial ischemia. The purpose of this study was to investigate the diagnostic performance of stress MBF, myocardial flow reserve (MFR) and myocardial flow capacity (MFC) derived from CZT SPECT in the detection of coronary artery disease (CAD)., Methods: One-hundred and eighty patients underwent two-day rest/adenosine-stress scans for SPECT MBF quantitation. All dynamic SPECT images were reconstructed and corrected with necessary corrections. The one-tissue two-compartment kinetic model was utilized to fit kinetic parameters (K1, k2 and FBV) by numeric optimization and converted to MBF from K1. Rest MBF, stress MBF and MFR in left ventricle and coronary territories were calculated from flow polar maps. MFC was assessed by extents of moderately and severely abnormal flow statuses using an integrated flow diagram. Per-patient and per-vessel analyses were performed to determine cutoff values for the detection of angiographically obstructive and flow-limited CAD., Results: Using the threshold of ≥ 50% stenosis, 149 patients (82.78%) were classified to have obstructive lesions in 355 vessels (65.74%). Using the threshold of ≥ 70% stenosis, 113 patients (62.78%) were classified to have flow-limited lesions in 282 vessels (52.22%). On per-patient analysis, the optimal cutoff values of stress MBF and MFR to detect ≥ 50% stenosis were (1.44 ml/min/g, 1.96) and (1.34 ml/min/g and 1.75) to detect ≥ 70% stenosis. The optimal cutoff values for severely and combined moderately severely abnormal MFC extents were (2.3-2.5%, 23.1%) and (7.5%, 29.4%), respectively. The overall sensitivity of MFC (0.84-0.86, 0.86-0.90) to detect ≥ 50% and ≥ 70% lesions surpassed those of stress MBF (0.78. 0.78) and MFR (0.80, 0.75) (all p < 0.05) with similar specificity (MFC = 0.84-0.90, 0.87-0.91; stress MBF = 0.87, 0.91; MFR = 0.84, 0.89) (all p≥ 0.05)., Conclusion: The non-invasive SPECT MBF quantitation using CZT SPECT is a reliable method to detect angiographically obstructive and flow-limited CAD. Myocardial flow capacity can outperform with higher diagnostic sensitivity than stress MBF or MFR alone., (© 2023. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

Objective: Incomplete recovery with long-term complications weeks beyond the acute coronavirus disease 2019 (COVID-19) infection is referred to as long COVID. Among the well-known long-term complications of COVID-19, myocardial damage is a frequently encountered side effect. Yet there is a lack of data for identifying high-risk patients who are more likely to develop long-term cardiovascular complications following COVID-19. Myocardial perfusion imaging (MPI) is the primary functional imaging modality in evaluating myocardial ischemia This study aimed to investigate the role of MPI in predicting myocardial ischemia in patients diagnosed with long COVID., Methods: Subjects were selected from eligible long COVID patients and control subjects without a prior history of COVID-19 who were referred to the nuclear medicine department for stress and rest single-photon emission computed tomography (SPECT) MPI. All participants' past medical records and clinical, and demographic characteristics were scanned. In addition, patients undergoing coronary angiography (CAG) following SPECT MPI were documented and patients with critical coronary stenosis were identified., Results: Our results revealed that long COVID patients had higher rates of abnormal summed stress scores compared to the control subjects (p < 0.05). Additionally, serum CRP level, SPECT lung-to-heart ratio (LHR), and the presence of long COVID were independent predictors of ischemia. The presence of long COVID was the best predictor of ischemia among the aforementioned parameters (p < 0.001)., Conclusion: Our data indicate that SPECT MPI provides comprehensive information on myocardial perfusion and left ventricular function in long COVID patients., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Coronary flow reserve (CFR) with positron emission tomography/computed tomography (PET/CT) has an important role in the diagnosis of coronary microvascular disease (CMD), aids risk stratification and may be useful in monitoring therapy. CMD contributes to symptoms and a worse prognosis in patients with coronary artery disease (CAD), nonischemic cardiomyopathies, and heart failure. CFR measurements may improve our understanding of the role of CMD in symptoms and prognosis in CAD and other cardiovascular diseases. The clinical presentation of CAD has changed. The prevalence of nonobstructive CAD has increased to about 50% of patients with angina undergoing angiography. Ischemia with nonobstructive arteries (INOCA) is recognized as an important cause of symptoms and has an adverse prognosis. Patients with INOCA may have ischemia due to CMD, epicardial vasospasm or diffuse nonobstructive CAD. Reduced CFR in patients with INOCA identifies a high-risk group that may benefit from management strategies specific for CMD. Although measurement of CFR by PET/CT has excellent accuracy and repeatability, use is limited by cost and availability. CFR measurement with single-photon emission tomography (SPECT) is feasible, validated, and would increase availability and use of CFR. Patients with CMD can be identified by reduced CFR and selected for specific therapies., (© 2022. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

We aimed to examine the associations of cardiovascular risk factors with myocardial perfusion reserve (MPR) in patients with type 2 diabetes and stable coronary artery disease. The study patients were retrospectively identified from a database of patients with diabetes and stable coronary artery disease at Asan Medical Center (Seoul, Republic of Korea), covering the period from 2017 to 2019. The primary outcome variable was MPR assessed by dynamic stress 201 Tl/rest 99m Tc-tetrofosmin SPECT. Univariable and stepwise multivariable analyses were performed to assess the associations of cardiovascular risk factors with MPR. A total of 276 patients (236 men and 40 women) were included. The median global MPR was 2.4 (interquartile range 1.9-3.0). Seventy-five (27.2%) patients had an MPR < 2.0. Multivariable linear regression showed that smoking (ß = - 0.44, 95% confidence interval - 0.68 to - 0.21, P < 0.001), hypertension (ß = - 0.24, 95% confidence interval - 0.47 to - 0.02, P = 0.033), and summed difference score (ß = - 0.05, 95% confidence interval - 0.07 to - 0.03, P < 0.001) were independently associated with MPR. Abnormal MPR (< 2.0) was associated with a higher incidence of cardiac death or myocardial infarction (P = 0.034). MPR assessed by dynamic stress 201 Tl/rest 99m Tc-tetrofosmin SPECT was impaired in a large cohort of patients with diabetes. After adjusting for risk variables, including standard myocardial perfusion imaging characteristics, smoking, and hypertension were associated with MPR. Our results may aid in identifying patients with impaired MPR and stratifying patients with type 2 diabetes., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Percutaneous coronary intervention can be a high-risk procedure that would benefit from optimizing device-tissue interactions between stents and coronary vessels. Using a perfusion-fixed human heart with coronary artery disease, we performed a percutaneous coronary intervention of the left main coronary artery bifurcation. This heart was perfused and multimodal imaging was utilized to view the procedure with direct visualization, fluoroscopy, and optical coherence tomography (OCT). We followed the European Bifurcation Club's guidelines to perform a single-stent bifurcation before transitioning to a two-stent Culotte technique. After each procedural step, the heart was removed from the perfusion apparatus and transferred to a micro-CT scanner to obtain unique scans. We conducted apposition analyses of the computational 3D models from micro-CT DICOM datasets, and compared them to the results from direct visualization and commercial OCT's Apposition Indicator software. Additional measurements of resulting coronary anatomic expansions were taken to determine the potential roles of each step in improving procedural outcomes. Micro-CT images show stent deformation during a percutaneous coronary intervention (provisional to Culotte bifurcation procedure) in an isolated diseased human heart., (© 2023. The Author(s).)

There is limited information on predicting incident cardiovascular outcomes among high- to very high-risk populations such as the elderly (≥ 65 years) in the absence of prior cardiovascular disease and the presence of non-cardiovascular multi-morbidity. We hypothesized that statistical/machine learning modeling can improve risk prediction, thus helping inform care management strategies. We defined a population from the Medicare health plan, a US government-funded program mostly for the elderly and varied levels of non-cardiovascular multi-morbidity. Participants were screened for cardiovascular disease (CVD), coronary or peripheral artery disease (CAD or PAD), heart failure (HF), atrial fibrillation (AF), ischemic stroke (IS), transient ischemic attack (TIA), and myocardial infarction (MI) for a 3-yr period in the comorbid history. They were followed up for up to 45.2 months. Analyses included descriptive approaches in terms of incidence rates and density ratios, and inferential in terms of main effect statistical/complex machine learning modeling. The contemporary risk factors of interest spanned across the domains of comorbidity, lifestyle, and healthcare utilization history. The cohort consisted of 154,551 individuals (mean age 68.8 years; 62.2% female). The overall crude incidence rate of CVD events was 9.9 new cases per 100 person-years. The highest rates among its component outcomes were obtained for CAD or PAD (3.6 for each), followed by HF (2.2) and AF (1.8), then IS (1.3), and finally TIA (1.0) and MI (0.9).Model performance was modest in terms of discriminatory power (C index: 0.67, 95%CI 0.667-0.674 for training; and 0.668, 95%CI 0.663-0.673 for validation data), equal agreement between predicted and observed events for calibration purposes, and good clinical utility in terms of a net benefit of 15 true positives per 100 patients relative to the All-patient treatment strategy. Complex models based on machine learning algorithms yielded incrementally better discriminatory power and much improved goodness-of-fitness tests from those based on main effect statistical modeling. This Medicare population represents a highly vulnerable group for incident CVD events. This population would benefit from an integrated approach to their care and management, including attention to their comorbidities and lifestyle factors, as well as medication adherence., (© 2023. The Author(s), under exclusive licence to Società Italiana di Medicina Interna (SIMI).)

Background: Positron emission tomography (PET) is the clinical gold standard for quantifying myocardial blood flow (MBF). Pericoronary adipose tissue (PCAT) attenuation may detect vascular inflammation indirectly. We examined the relationship between MBF by PET and plaque burden and PCAT on coronary CT angiography (CCTA)., Methods: This post hoc analysis of the PACIFIC trial included 208 patients with suspected coronary artery disease (CAD) who underwent [ 15 O]H 2 O PET and CCTA. Low-attenuation plaque (LAP, < 30HU), non-calcified plaque (NCP), and PCAT attenuation were measured by CCTA., Results: In 582 vessels, 211 (36.3%) had impaired per-vessel hyperemic MBF (≤ 2.30 mL/min/g). In multivariable analysis, LAP burden was independently and consistently associated with impaired hyperemic MBF (P = 0.016); over NCP burden (P = 0.997). Addition of LAP burden improved predictive performance for impaired hyperemic MBF from a model with CAD severity and calcified plaque burden (P < 0.001). There was no correlation between PCAT attenuation and hyperemic MBF (r = - 0.11), and PCAT attenuation was not associated with impaired hyperemic MBF in univariable or multivariable analysis of all vessels (P > 0.1)., Conclusion: In patients with stable CAD, LAP burden was independently associated with impaired hyperemic MBF and a stronger predictor of impaired hyperemic MBF than NCP burden. There was no association between PCAT attenuation and hyperemic MBF., (© 2023. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

Background: Clinical practice shows degrading image quality in heavier patients who undergo myocardial perfusion imaging (MPI) with Rubidium-82 (Rb-82) PET when using a fixed tracer activity. Our aim was to derive and validate a patient-specific activity protocol resulting in a constant image quality in PET MPI., Methods: We included 251 patients who underwent rest MPI with Rb-82 PET (Discovery 670, GE Healthcare). 132 patients were included retrospectively and were scanned using a fixed activity of 740 MBq. The total number of measured prompts was normalized to activity and correlated to body weight, mass per body length and body mass index to find the best predicting parameter. Next, a patient-specific activity was derived and subsequently validated in 119 additional patients. Image quality was scored by three experts on a four-point scale., Results: Both image quality and prompts decreased in heavier patients when using a fixed activity (p < .005). Body weight was used to derive a new activity formula: Activity = 8.3 MBq/kg. When applying this formula, both measured prompts and scored image quality became independent of body weight (p > .60)., Conclusion: Administrating a Rb-82 activity that linearly depends on body weight resulted in a constant image quality across all patients and is recommended., (© 2019. American Society of Nuclear Cardiology.)

In 2022, the Journal of Nuclear Cardiology® published many excellent original research articles and editorials focusing on imaging in patients with cardiovascular disease. In this review of 2022, we summarize a selection of articles to provide a concise recap of major advancements in the field. In the first part of this 2-part series, we addressed publications pertaining to single-photon emission computed tomography. In this second part, we focus on positron emission tomography, cardiac computed tomography, and cardiac magnetic resonance. We specifically review advances in imaging of non-ischemic cardiomyopathy, cardio-oncology, infectious disease cardiac manifestations, atrial fibrillation, detection and prognostication of atherosclerosis, and technical improvements in the field. We hope that this review will be useful to readers as a reminder to articles they have seen during the year as well as ones they have missed., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Objectives: The aim of this prospective multi-center study was to investigate the diagnostic value of myocardial blood flow (MBF) quantification using NaI(Tl)-based single-photon emission computed tomography (SPECT) for determining coronary artery disease (CAD) defined by quantitative coronary angiography (QCA)., Background: Absolute quantitation of MBF and myocardial flow reserve (MFR) using SPECT is clinically feasible; however, whether flow quantification using NaI(Tl) SPECT is superior to commonly performed SPECT myocardial perfusion imaging (MPI) in determining CAD has not been evaluated., Methods: Patients with suspected or known CAD underwent pharmacological stress/rest dynamic SPECT imaging and routine SPECT MPI followed by QCA. Obstructive disease was defined as ≥ 50% reduction in luminal diameter on QCA., Results: One hundred fifty-four patients (462 vessels) were included in the analysis. Obstructive CAD was detected in 76/154 patients (49.4%) and 112/462 vessels (24.2%). Optimal cut-off values were 1.86 mL/min/g for stress MBF and 1.95 for MFR, respectively. Stress MBF and MFR were more sensitive than MPI in both individual patients (stress MBF vs MPI: 81.6% vs 51.3%; MFR vs MPI: 72.4% vs 51.3%) and in coronary vascular regions (stress MBF vs MPI: 78.6% vs 31.3%; MFR vs MPI: 75.9% vs 31.3%; all P < .01). In receiver operating characteristic curve analysis, quantification revealed a significantly greater area under the curve than MPI at the patient (stress MBF vs MPI: 0.761 vs 0.641; MFR vs MPI: 0.770 vs 0.641) and the vessel (stress MBF vs MPI: 0.745 vs 0.613; MFR vs MPI: 0.756 vs 0.613; all P < .05) levels. Integrating quantitative SPECT measures with MPI significantly increased the area under the curve and improved the discriminatory and reclassification capacity., Conclusion: Flow quantification using NaI(Tl) SPECT provides superior sensitivity and discriminatory capacity to MPI in detecting significant stenosis. Clinical trial registration NCT03637725., (© 2022. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.)

Coronary flow capacity (CFC) categorizes severity of left ventricular (LV) ischemia by PET myocardial blood flow (MBF). Our objective was to correlate abnormal CFC with other indicators of regional ischemia. Data were examined retrospectively for 231 patients evaluated for known/suspected CAD who underwent rest and regadenoson-stress 82 Rb PET/CT. MBF and myocardial flow reserve (MFR) were quantified, from which CFC was categorized as Normal CFC (1), Minimally reduced (2), Mildly reduced (3), Moderately reduced (4), and Severely reduced (5) for the three main arterial territories as well as globally. Relative perfusion summed stress score (SSS) and systolic phase contraction bandwidth (BW) were assessed. Accuracy to detect arteries with CFC ≥ 4 was highest for a Regional Index combining SSS and BW (88 ± 3%). A Global Index formed from stress ejection fraction, SSS and BW was the most accurate means of identifying patients with global CFC ≥ 4 (84 ± 3%). Arteries with abnormal CFC derived from absolute myocardial blood flow measurements are accurately identified by composite parameters combining regionally aberrant relative perfusion patterns and asynchrony., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: Myocardial blood flow (MBF) and myocardial flow reserve (MFR) are measurable by 13 N-NH 3 positron emission tomography (PET). MFR, which is the ratio of MBF under adenosine stress to MBF at rest, is prognostically valuable. The ASNC imaging guidelines/SNMMI procedure standards recommend using 2-3 mm pixels, and pixel size does differ between institutions. We sought to evaluate the effects of pixel sizes on the quantitative values calculated from 13 N-NH 3 PET images., Methods: Thirty consecutive patients with ischemic heart disease who underwent 13 N-NH 3 PET were retrospectively enrolled. Dynamic images were quantified using PMOD's cardiac PET analysis tool (pixel sizes: 3.18, 2.03, and 1.59 mm). MBF under adenosine stress, MBF at rest, and MFR for the right coronary artery (RCA) region, left anterior descending artery region, and left circumflex coronary artery branch region innervation regions were calculated at each pixel size and compared., Results: Quantitative values did not significantly differ according to pixel size in any of the regions. However, MFR values for the RCA fluctuated the most. Ischemic and non-ischemic regions remained visually discernible in qualitative images, with no variation in quantitative values, regardless of pixel size., Conclusions: Quantitative values were not significantly affected by pixel sizes within the recommended range of 2-3 mm. Values for the RCA region may have been overestimated, but this was true for all pixel sizes., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Risk stratification and diagnosis using Rubidium-82 ( 82 Rb) positron emission tomography (PET) is a routine clinical approach in coronary artery disease (CAD). Various drugs are used to treat CAD; however, whether any of them change the uptake of 82 Rb in the heart has not been investigated. The aim of this study is to determine whether drugs used in treatment of CAD affect the uptake of 82 Rb in the heart in healthy rats., Methods: Seventy-seven Sprague-Dawley rats were included in the cross-sectional study. All rats underwent baseline 82 Rb PET/CT and divided into eleven groups treated with different drugs. One group was control group (no treatment), eight groups were treated with monotherapy (amiodarone, acetylsalicylic acid (ASA), clopidogrel, ticagrelor, atorvastatin, enalapril, amlodipine, metoprolol succinate), and two groups were treated with polypharmacy (ASA, ticagrelor, atorvastatin, amlodipine or ASA, clopidogrel, atorvastatin, amlodipine). Once a day, they were administered pharmacological therapy through oral gavage, and on day seven, follow-up scanned with 82 Rb PET/CT., Results: In the control group without pharmacological treatment, no difference in the standard uptake value (SUV) ratio between heart and muscle from baseline to follow-up (5.8 vs 7.0, P = .3) was found. The group treated with amiodarone had a significantly reduced SUV ratio from baseline to follow-up (5.8 vs 5.1, P = .008). All other drugs investigated had no difference in SUV ratio from baseline to follow-up., Conclusion: In this study, we showed that drugs normally used to treat CAD do not affect the uptake of 82 Rb. However, amiodarone result in a significantly lowered 82 Rb uptake, compared to control. This information about amiodarone would probably not change the size assessment of a myocardial perfusion defect in a clinical setting. However, it could change the kinetic parameters when assessing absolute myocardial blood flow in patients treated with amiodarone., (© 2021. American Society of Nuclear Cardiology.)

Background: Cardiovascular diseases are the leading cause of mortality, morbidity, and disability in the world, especially in the older adults. A relevant proportion of patients admitted to Cardiac Rehabilitation (CR) may suffer from frailty, a complex geriatric syndrome with multifactorial aetiology., Aims: The hypothesis underlying the study is that frailty complicates the management of older patients undergoing CR. The main objective is, therefore, to determine the relationship between frailty and CR outcomes in hospitalized older adults., Methods: The participants have been recruited among patients aged ≥ 65 years admitted at the hospital for CR. A Comprehensive Geriatric Assessment (CGA)-based Frailty Index (FI) was created following a standard procedure. The outcome was measured as the ratio between 6-min walk test (6MWT) distance at the end of CR and normal predicted values for a healthy adult of same age and gender, according to reference equations., Results: The study population consisted of 559 elderly patients, 387 males (69.2%), with age of 72 (69-76) years. The most frequent diagnosis at admission was ischaemic heart disease (231, 41.5%) and overall 6MWT ratio was 0.62 ± 0.21. At the multivariable regression analysis, gender, diagnosis and FI were significantly and independently associated with 6MWT ratio (p ≤ 0.0001, p ≤ 0.001 and p ≤ 0.0001, respectively), while no significant association emerged for age., Conclusion: FI resulted independently correlated to 6MWT ratio in a population of older patients undergoing in-hospital CR programs. Frailty is a multifactorial geriatric syndrome whose assessment is essential for prognostic evaluation of older patients, also in CR clinical setting., (© 2022. The Author(s).)

Background: PET myocardial flow reserve (MFR) has established diagnostic and prognostic value. Technological advances have now enabled SPECT MFR quantification. We investigated whether SPECT MFR precision is sufficient for clinical categorization of patients., Methods: Validation studies vs invasive flow measurements and PET MFR were reviewed to determine global SPECT MFR thresholds. Studies vs PET and a SPECT MFR repeatability study were used to establish imprecision in SPECT MFR measurements as the standard deviation of the difference between SPECT and PET MFR, or test-retest SPECT MFR. Simulations were used to evaluate the impact of SPECT MFR imprecision on confidence of clinically relevant categorization., Results: Based on validation studies, the typical PET MFR categories were used for SPECT MFR classification (< 1.5, 1.5-2.0, > 2.0). Imprecision vs PET MFR ranged from 0.556 to 0.829, and test-retest imprecision was 0.781-0.878. Simulations showed correct classification of up to only 34% of patients when 1.5 ≤ true MFR ≤ 2.0. Categorization with high confidence (> 80%) was only achieved for extreme MFR values (< 1.0 or > 2.5), with correct classification in only 15% of patients in a typical lab with MFR of 1.8 ± 0.5., Conclusions: Current SPECT-derived estimates of MFR lack precision and require further optimization for clinical risk stratification., (© 2021. American Society of Nuclear Cardiology.)

Background: 13 N-ammonia and 18 F-flurpiridaz require longer delays between rest and stress studies to allow for decay, lowering clinical throughput. In this study, we investigated the impact of residual subtraction on MBF and MFR estimates, as well as its effects on diagnostic accuracy., Methods: We retrospectively analyzed 63 patients who underwent a dynamic ammonia rest/stress study and 231 patients from the flurpiridaz 301 trial. Residual subtraction was performed by subtracting the mean pre-injection activity in each sampled region from that region's time activity curve. Corrected and uncorrected MBF and MFR were analyzed. Diagnostic accuracy was compared to quantitative coronary angiograms (QCA) for the flurpiridaz population., Results: With delays between injections above 3 half-lives, and a doubled stress dose, residual activity did not meaningfully increase ammonia MBF (< 5%). For shorter injection delays, stress MBF was overestimated by 13.6% ± 5.0% (P < .001). Residual activity had a large effect on flurpiridaz stress MBF, overestimating it by 37.9% ± 23.2% (P < .001). Comparison to QCA showed a significant improvement in AUC with residual subtraction (from 0.748 to 0.831, P = .001). MFR yielded similar results., Conclusions: Accounting for residual activity has a marked impact on stress MBF and MFR and improves diagnostic accuracy relative to QCA., (© 2021. American Society of Nuclear Cardiology.)

To investigate the relationship between the epicardial adipose tissue density (EATD) and the coronary plaque components as assessed by coronary computed tomographic angiography (CCTA). The study cohort included 240 patients with chest pain or precardiac discomfort (mean age 62.01 ± 7.45 years, 55.83% male). Patients were assigned to the high-risk plaque (HRP) group (n = 133) or non-HRP group (n = 107). All patients underwent CCTA to assess plaque composition, and quantitative analysis of EATD and epicardial adipose tissue volume (EATV). Age, gender, EATV, EATD, diabetes history and family history were all correlated with HRP. There was no linear correlation between EATD and EATV among the subjects (R 2  = 0.008, p = 0.177), but there was a curvilinear correlation (R 2  = 0.102, p < 0.001). After adjusting other traditional factors, and we observed robust associations of EAT volume and density with HRP (all p < 0.05). For per 1 standard deviation increase in EATD, the risk of HRP was 3.120 times the risk than that of non-HRP. For per 1 standard deviation increase in EATV, the risk of HRP was 1.499 times the risk than that of non-HRP. The receiver operating characteristic curve showed that EATD was more predictive of HRP than EATV (AUC = 0.761, 95% CI 0.701-0.822). Our study found that EATD and EATV are both independent factors affecting the presence of HRPs, and EATD had a high predictive value for the presence of HRP., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

To explore the feasibility and efficacy of radiomics with left ventricular tomograms obtained from D-SPECT myocardial perfusion imaging (MPI) for auxiliary diagnosis of myocardial ischemia in coronary artery disease (CAD). The images of 103 patients with CAD myocardial ischemia between September 2020 and April 2021 were retrospectively selected. After information desensitization processing, format conversion, annotation using the Labelme tool on an open-source platform, lesion classification, and establishment of a database, the images were cropped for analysis. The ResNet18 model was used to automate two steps (classification and segmentation) with five randomization, training and validation steps. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, negative predictive value, Youden's index, agreement rate, and kappa value were calculated as evaluation indexes of the classification results for each training-validation step; then, receiver operating characteristics (ROC) curves were drawn, and the areas under the curve (AUCs) were calculated. The Dice coefficient, intersection over union, and Hausdorff distance were calculated as evaluation indexes of the segmentation results for each training-validation step; then, the predicted images were exported. Under the existing conditions, the radiomics model used in this study had an AUC above 0.95 in identifying the presence or absence of myocardial ischemia; in the prediction of the extent of myocardial ischemia, its evaluation index distribution is also close to that of the gold standard. Radiomics can be feasibly applied to left ventricular tomograms obtained from D-SPECT MPI for auxiliary diagnosis. With more in-depth research and the development of technology, adding this method to the existing auxiliary diagnosis will likely further improve the diagnostic accuracy and efficiency, and patients will therefore benefit., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

The conventional criteria for a defibrillation lead (DL) implantation don't take into account presence of scar or deep ischemia in the myocardium. This may impair a proper functioning of the DL. We sought to optimize the DL implantation placement using rest myocardial perfusion scintigraphy (MPS), which allow detecting areas of myocardial hypoperfusion (MH). To study the influence of MH and scarring, detected by MPS, on the DL parameters in patients with coronary artery disease (CAD). 69 patients (male-65, age 64.8 ± 7.7 years) with CAD and indications for ICD implantation were enrolled. Two days before ICD implantation all patients underwent MPS at rest. Then patients were divided in 2 groups. In the 1st group DL was implanted considering MPS results: to the septal position, if the most significant MH were detected in the apical segments, and to the apical position, if MH were in the septal segments. In the 2nd group DL was implanted using the conventional approach without considering MPS results. Clinical 12 months follow-up was performed with ICD interrogation. Patients of both groups were comparable by clinical and scintigraphic parameters. In the same time, in the 1st group pacing threshold was lower (p < 0.0001) and ventricle signal amplitude was higher (p < 0.0001) comparing with the 2nd group at all control points. The presence of MH detected by MPS in the area of the DL placement worsens its parameters. The results of MPS in patients with CAD can be useful for optimization of DL placement., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: PET/CT is the standard for quantitative assessments of myocardial blood flow (MBF), but it requires short-lived-tracers, costly, and not widely available. SPECT with Cadmium Zinc Telluride (CZT) detectors allows dynamic acquisition and quantitation of MBF. The study aims were to compare MBF measurements by 99m Tc-tetrofosmin-CZT to N 13 NH 3 PET/CT after regadenoson-induced coronary hyperemia and to evaluate the effect of attenuation correction (AC)., Methods: 54 patients were evaluated at rest and during vasodilation by 99m Tc-tetrofosmin-CZT and N 13 NH 3 PET/CT within 2 weeks. MBF and MBF reserve (MFR) were measured by CZT with or without AC (NAC)., Results: The global rest MBF was 0.76 ± 0.19 mL/min/gr by PET and 0.76 ± 0.24 by AC-CZT (P = NS) and 1.14 ± 0.4 by NAC-CZT (P < 0.001 vs PET and AC-CZT). Stress MBF was higher when measured by PET than AC-CZT (1.87 ± 0.45 vs 1.62 ± 0.68 mL/min/gr, P < 0.0008), but lower than NAC-CZT (2.36 ± 1.1, P < 0.0003). The MBF reserve ratio (MFR) was higher by PET than AC-CZT (2.52 ± 0.56 vs 2.22 ± 1 (P < 0.009) and NAC-CZT (2.18 ± 1.0, P < 0.004). Linear regression was better between PET (MFR and stress MBF) and AC-CZT than between PET and NAC-CZT. ROC curve analysis showed the significant ability of AC-CZT to predict MFR < 2 and stress MBF < 1.7 (AUC = 0.75 and 0.82 respectively) and to differentiate between normal and CAD patients (AUC = 0.747 and 0.892 for MFR and stress MBF, respectively)., Conclusions: Our data show a reasonable correlation between MBF and MFR measured by N 13 NH 3 -PET and 99m Tc-Tetrofosmin-CZT SPECT. NAC-CZT overestimates MBF. AC is recommended when using CZT for measuring MBF., (© 2019. American Society of Nuclear Cardiology.)

Background: 18 F-Flurpiridaz is a promising investigational radiotracer for PET myocardial perfusion imaging with favorable properties for quantification of myocardial blood flow (MBF). We sought to validate the incremental diagnostic value of absolute MBF quantification in a large multicenter trial against quantitative coronary angiography., Methods: We retrospectively analyzed a subset of patients (N = 231) from the first phase 3 flurpiridaz trial (NCT01347710). Dynamic PET data at rest and pharmacologic stress were fit to a previously validated 2-tissue-compartment model. Absolute MBF and myocardial flow reserve (MFR) were compared with coronary artery disease severity quantified by invasive coronary angiography on a per-patient and per-vessel basis., Results: Stress MBF per-vessel accurately identified obstructive disease (c-index 0.79) and progressively declined with increasing stenosis severity (2.35 ± 0.71 in patients without CAD; 1.92 ± 0.49 in non-obstructed territories of CAD patients; and 1.54 ± 0.50 in diseased territories, P < 0.05). MFR similarly declined with increasing stenosis severity (3.03 ± 0.94; 2.69 ± 0.95; and 2.33 ± 0.86, respectively, P < 0.05). In multivariable logistic regression modeling, stress MBF and MFR provided incremental diagnostic value beyond patient characteristics and relative perfusion analysis., Conclusions: Clinical myocardial blood flow measurement with 18 F-flurpiridaz cardiac PET shows promise for routine application., (© 2020. American Society of Nuclear Cardiology.)

Purpose: To determine the relationship between non-alcoholic fatty liver disease (NAFLD) evaluated by a hepatic fat fraction (HFF) using dual-energy computed tomography (DECT) and high-risk coronary plaques (HRP) in NAFLD patients., Methods: We conducted a matched case-control study involving 172 NAFLD individuals recruited from August 2019 to September 2020. They underwent dual-energy coronary computed tomographic angiography and were classified as no-plaque, HRP negative and HRP positive groups. HFF values were measured using multimaterial decomposition algorithm of DECT, and the differences among three groups were compared. Multiple logistic regression analysis was performed to determine the independent correlation between HFF and HRP. Spearman rank correlation was used to assess the correlations between HFF and multiple variables., Results: HRP positive group (15.3%) had higher HFF values than no-plaque (6.9%) and HRP negative groups (8.9%) (P < 0.001). After adjusting for confounding variables, the results indicated that HFF was an independent risk factor for HRP (OR 1.93, P < 0.001). Additionally, HFF significantly correlated with coronary artery calcium score, hepatic CT attenuation, epicardial and pericoronary adipose tissue volume, and CT attenuation (all P < 0.001)., Conclusions: As a new imaging marker for the quantification of liver fat, HFF was independently associated with HRP., (© 2021. Japan Radiological Society.)

Background: Patient motion during pharmacological stressing can have substantial impact on myocardial blood flow (MBF) estimated from dynamic PET. This work evaluated a motion correction algorithm with and without adjustment of the PET attenuation map., Methods: Frame-by-frame motion correction was performed by three users on 30 rubidium-82 studies. Data were divided equally into three groups of motion severity [mild (M1), moderate (M2) and severe (M3)]. MBF data were compared for non-motion corrected (NC), motion-corrected-only (MC) and with adjustment of the attenuation map (MCAC). Percentage differences of MBF were calculated in the coronary territories and 17-segment polar plots. Polar plots of spill-over were also generated from the data., Results: Median differences of 23% were seen in the RCA and 18% for the LAD in the M3 category for MC vs NC images. Differences for MCAC vs MC images were considerably smaller and typically < 10%. Spill-over plots for MC and MCAC were notably more uniform compared with NC images., Conclusion: Motion correction for dynamic rubidium data is desirable for future MBF software updates. Adjustment of the PET attenuation map results in only marginal differences and therefore is unlikely to be an essential requirement. Assessing the uniformity of spill-over plots is a useful visual aid for verifying motion correction techniques., (© 2019. American Society of Nuclear Cardiology.)

Background: Quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) has shown diagnostic and prognostic values for the assessment of coronary artery disease (CAD). This study aimed to evaluate in patients a highly automatic Yale-MQ (myocardial blood flow quantification) software incorporated with a novel image segmentation approach for quantification of global and regional MBF and MFR from dynamic 82 Rb cardiac positron emission tomography (PET)., Methods: Global and regional MBFs and MFRs were quantified in 80 patients (18 normal and 62 CAD subjects) by two different observers using the Yale-MQ software. Lower limits of normal (LLN) values and intra- and inter-observer variabilities of MBFs and MFRs were calculated for the assessment of quantitative precision. The Yale-MQ was compared with a commercially available software (Corridor 4DM) being used as a reference., Results: The Yale-MQ method provided precise assessments of LLNs of MBF and MFR. The global and regional MBFs and MFR quantified via Yale-MQ were correlated strongly with those via Corridor4DM (R ≥ 0.867). The intra- and inter-observer variabilities of MBFs and MFRs quantified via Yale-MQ were small (≤ 7.7% for MBFs and ≤ 10.0% for MFRs) with excellent correlations (R ≥ 0.980 for MBFs and R ≥ 0.976 for MFRs)., Conclusions: The new Yale-MQ software associated with the automatic processing scheme provides a highly reproducible clinical tool for precise quantification of MBF and MFR in patients with reliable LLN values., (© 2020. American Society of Nuclear Cardiology.)

Background: We tested the repeatability of myocardial blood flow (MBF) quantified using 82 Rb with and without motion correction (MC) and with arterial input functions estimated from left ventricle (LV) and atrium (LA)., Methods: Twenty-one patients referred for clinical 82 Rb PET/CT underwent repeated rest scans in a single imaging session. Global MBF was quantified using three different assessments by two operators: (1) automatic processing without MC and LV arterial input function (AIF), (2) with MC and LV-AIF, and (3) with MC and LA-AIF. Inter-scan and inter-operator repeatability were tested using coefficient of variation (CV)., Results: MC with LV-AIF did not change MBF (no MC: 1.01 ± 0.30 mL/min/g vs MC with LV-AIF: 1.01 ± 0.29, P = 0.70), whereas MC with LA-AIF showed significantly lower MBF assessments (0.95 ± 0.28 mL/min/g, P = 0.0006). We report significant improvement for test-retest reproducibility for global MBF following MC (CV; No MC: 16.0, MC (LV-AIF): 9.2, MC (LA-AIF): 8.8). Good inter-operator repeatability was observed for LV-AIF (CV = 4.7) and LA-AIF (CV = 5.6) for global MBF assessments., Conclusions: MC significantly improved the test-retest repeatability between operators and between scans. MBF obtained after MC with LV-AIF were comparable, whereas MBFs after MC and LA-AIF were significantly reduced., (© 2019. American Society of Nuclear Cardiology.)

We aimed to identify predictors of late lumen enlargement (LLE) after drug-coated balloon (DCB) angioplasty for de novo coronary lesions. LLE, which is defined as an increase in the luminal diameter of the vessel from the immediate postprocedural measurement to follow-up measurements, is frequently observed after DCB angioplasty for de novo coronary artery disease. No predictors of LLE are known. This retrospective observational study analyzed 196 de novo coronary lesions in 182 patients who underwent both DCB angioplasty and follow-up angiography. Of the 196 lesions, 109 (56%) developed LLE during a mean follow-up period of 7.2 ± 2.5 months. As defined by American College of Cardiology (ACC)/American Heart Association (AHA) lesion types, lesions with LLE were significantly less severe than lesions without LLE (types A, B1, B2 and C 15%, 35%, 38% and 13% vs. 7%, 24%, 45% and 24%, respectively; p = 0.036), although no significant differences in clinical or other lesion background characteristics were observed between the groups. Among type C lesions, chronic total occlusion (CTO) was more frequently observed in lesions with LLE than in lesions without LLE (79% vs 43%, p = 0.036). Lesion severity predicts LLE after DCB angioplasty for de novo coronary artery disease. Among type C lesions, CTO is expected in lesions showing LLE, and preparations should therefore be made prior to DCB application. Further research is needed.

Background: Asynchrony has been reported to be a marker of ischemic-induced left ventricular dysfunction, the magnitude of which correlates with extent of epicardial coronary disease. We wished to determine whether normal-appearing arterial territories with mild degrees of asynchrony have lower 82 Rb PET absolute myocardial blood flow (MBF) and/or lower myocardial flow reserve (MFR)., Methods and Results: Data were examined retrospectively for 105 patients evaluated for known/suspected CAD who underwent rest/regadenoson-stress 82 Rb PET/CT and quantitative coronary angiography. Rest and stress absolute MBF and MFR were quantified from first-pass 82 Rb PET curves. Regional relative myocardial perfusion summed stress score (SSS), summed rest score (SRS), regional phase bandwidth (BW), and regional semi-quantitative asynchrony visual scores of (Asynch) were assessed. We found that in apparently normal arteries (SSS < 4, SRS < 4 and stenosis < 70%), those with abnormally low MFR < 2.0 compared to those with MFR ≥ 2.0 had larger phase BW (186 ± 79° vs 158 ± 67°, P = .02), and more visually apparent Asynch (5.7 ± 4.2 vs 3.9 ± 3.6, P = .02), which was associated with increasing stenosis values (ρ = 0.44, P < .0001)., Conclusion: A subgroup of coronary territories with normal relative perfusion and normal or non-obstructive coronary disease may have reduced MFR, which is signaled physiologically by a mild degree of left ventricular asynchrony.

The life expectancy of people infected with human immunodeficiency virus (HIV) is rising due to better access to combination anti-retroviral therapy (ART). Although ART has reduced acquired immune deficiency syndrome (AIDS) related mortality and morbidity, there has been an increase in non-AIDS defining illnesses such as diabetes mellitus, hypercholesterolemia and coronary artery disease (CAD). HIV is a disease marked by inflammation which has been associated with specific biological vascular processes increasing the risk of premature atherosclerosis. The combination of pre-existing risk factors, atherosclerosis, ART, opportunistic infections and coagulopathy contributes to rising CAD incidence. The prevalence of CAD has emerged as a major contributor of morbidity in these patients due to longer life expectancy. However, ART has been associated with lipodystrophy, dyslipidemia, insulin resistance, diabetes mellitus and CAD. These adverse effects, along with drug-drug interactions when ART is combined with cardiovascular drugs, result in significant challenges in the care of this group of patients. Exercise tolerance testing, echocardiography, myocardial perfusion imaging, coronary computed tomography angiography and magnetic resonance imaging help in the diagnosis of CAD and heart failure and help predict cardiovascular outcomes in a manner similar to non-infected individuals. This review will highlight the pathogenesis and factors that link HIV to CAD, presentation and treatment of HIV-patients presenting with CAD and review briefly the cardiac imaging modalities used to identify this entity and help prognosticate future outcomes.

Purpose: To define the diagnostic power of absolute myocardial blood flow (MBF) evaluation on dynamic CZT imaging in intermediate risk patients in comparison with invasive coronary angiography (ICA) and fractional flow reserve (FFR)., Methods: Twenty-three stable CAD patients underwent one-day dynamic rest-stress 99mTc-Sestamibi myocardial perfusion imaging by CZT camera. Stress and rest MBF values were calculated semi-automatically using a net retention model by Leppo. Coronary flow reserve (CFR) and flow difference (FD) [MBF stress - MBF rest] were also estimated. A total of 28 vessels were functionally quantified with FFR: 19 (68%) vessels with a stenosis ≥ 70% and 9 (32%) with < 70% stenotic lesions., Results: The mean global MBFs at rest and during stress were 0.36 (IQR 0.33-0.54) mL/min/g and 0.67 (IQR 0.55-0.81) mL/min/g, respectively, with an average CFR of 1.80 (IQR 1.35-2.24). Moderate correlations between stenosis severity and FFR (r = 0.45; P = .01), stress MBF (r = -0.46; P = .01) and FD (r = -0.37; P = .04) were detected. FFR abnormalities were best predicted by absolute stress MBF, CFR and FD with values of ≤ 0.54 mL/min/g (sensitivity 61.5%; specificity 93.3%), ≤ 1.48 (sensitivity 69.2%; specificity 93.3%) and ≤ 0.18 mL/min/g (sensitivity 69.2%; specificity 100%), respectively., Conclusions: The values of stress MBF, CFR and FD obtained through dynamic CZT acquisitions compare well with invasive FFR. The clinical use of dynamic acquisition of myocardial perfusion imaging by CZT may help cardiologist in the detection of hemodynamically significant CAD.

Introduction: The transradial approach is the standard for percutaneous coronary intervention (PCI). Moreover, to lead to the evolution of PCI, a new approach site was developed, namely the distal radial approach (dRA)., Anatomy and Vessel Diameter: The vessel diameter of the distal radial artery is smaller than that of the forearm radial artery; hence, use of 1 Fr size or a sheath with a thinner outer diameter is recommended. Ultrasound examination before the procedure provides useful information on this matter., Puncture: There are two approaches to puncture: proximal site puncture of the distal radial artery and distal site puncture. Based on anatomical characteristics, the puncture angle is large on the former and small on the latter. Although a learning curve for the dRA puncture is needed, the use of ultrasound facilitates the process., Hemostasis: Using a hemostatic device dedicated to the dRA simplifies observation after PCI. Hemostatic devices for the conventional radial approach or simple bandage with an elastic band can be useful. Usually, less hemostasis time is needed for the dRA compared with the conventional radial approach., Success Rate: Studies have shown high success rates of the dRA (approximately 88-99.5%)., Advantages and Disadvantages: Advantages of the dRA are patient comfort, short hemostasis time, less restraint for the patients after PCI, and easy observation at the ward. Disadvantages are the learning curve required for the puncture and the small diameter of the distal radial artery., Conclusion: The dRA is a new approach site for PCI. Further research is warranted for the selection of suitable patients to undergo PCI through the dRA.

Background: We have previously found that pioglitazone attenuates inflammation in the left main trunk of coronary artery (LMT), evaluated as target-to-background ratio (TBR) by 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with impaired glucose tolerance or type 2 diabetes., Objectives: We assessed which clinical variables could predict the change in TBR in the LMT after 4-month add-on therapy with oral hypoglycemic agents (OHAs)., Methods: A total of 38 type 2 diabetic patients with carotid atherosclerosis who had already received OHAs except for pioglitazone was enrolled. At baseline and 4 months after add-on therapy with pioglitazone or glimepiride, all patients underwent 75 g oral glucose tolerance test, blood chemistry analysis, and FDG-PET/CT., Results: Fasting plasma glucose, 30-, 60-, 90-, 120-minutes postload plasma glucose, HbA1c, and LMT-TBR values were significantly decreased by add-on therapy, whereas high-density lipoprotein-cholesterol and adiponectin levels were increased. Increased serum levels of pigment epithelium-derived factor (PEDF), a marker of insulin resistance and non-use of aspirin at baseline could predict the favorable response of LMT-TBR to add-on therapy. Moreover, Δ120-minutes postload plasma glucose and ΔPEDF were independent correlates of ΔLMT-TBR., Conclusions: Our present study suggests that 120-minutes postload plasma glucose and PEDF values may be markers and potential therapeutic targets of coronary artery inflammation in type 2 diabetic patients., Clinical Trial Registration: URL: http://clinicaltrials.gov . Unique identifier: NCT00722631. New markers for diabetes and CAD is on the horizon! Two-hour postload plasma glucose and pigment epithelium derived factor are markers of coronary artery inflammation in type 2 diabetic patients.

Objective: 82 Rb PET/CT rest/regadenoson-stress data enable quantification of left ventricular rest and stress function, perfusion, and asynchrony. Our study was conducted to determine which parameters best identify patients with multi-vessel disease (MVD) and individual stenosed arteries., Methods: PET/CT data were reviewed retrospectively for 105 patients referred for evaluation of CAD, who also underwent angiography. % arterial stenosis was determined quantitatively at a core laboratory. Severe stenosis was defined as ≥ 70%, and MVD as 2 or more stenosed arteries. Segmental MBF was calculated from first-pass data for arterial territories. Regional rest and stress systolic and diastolic asynchrony (Asynch) scores were determined from visual examination of phase polar maps., Results: 65 vessels had stenoses ≥ 70%. 15 patients had MVD. ROC area under curve (ROC AUC) for identifying patients with MVD was 83% for Asynch and 73% for MFR. ROC AUC for identifying individual arterial territories with stenoses ≥ 70% was 81% and 72% for Asynch and MFR., Conclusion: 82 Rb PET/CT accurately identified patients with MVD and individual stenosed territories, with regional asynchrony measurements contributing significantly to identify patients with CAD.

Competing Interests: DECLARATION OF COMPETING INTEREST The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kevin Cheng reports a relationship with British Heart Foundation that includes: funding grants. Ranil de Silva reports a relationship with British Heart Foundation that includes: funding grants. Ranil de Silva reports a relationship with Neovasc Inc that includes: consulting or advisory, funding grants, and speaking and lecture fees. Ranil de Silva reports a relationship with Shockwave Medical Inc that includes: consulting or advisory, funding grants, and speaking and lecture fees. Ranil de Silva reports a relationship with Abbott Vascular Inc that includes: consulting or advisory, funding grants, and speaking and lecture fees. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Coronary angiography (CAG) is the "gold standard" for diagnosing coronary artery disease (CAD). However, due to the limitation of current imaging methods, the CAG image has low resolution and poor contrast with a lot of artifacts and noise, which makes it difficult for blood vessels segmentation. In this paper, we propose a DBCU-Net for automatic segmentation of CAG images, which is an extension of U-Net, DenseNet with bi-directional ConvLSTM(BConvLSTM). The main contribution of our network is that instead of convolution in the feature extraction of U-Net, we incorporate dense connectivity and the bi-directional ConvLSTM to highlight salient features. We conduct our experiment on our private dataset, and achieve average Accuracy, Precision, Recall and F1-score for coronary artery segmentation of 0.985, 0.913, 0.847 and 0.879 respectively., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)