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The evolution of simulated robots with three different architectures is studied. We compared a non-modular feed forward network, a hardwired modular and a duplication-based modular motor control network. We conclude that both modular architectures outperform the non-modular architecture, both in terms of rate of adaptation as well as the level of adaptation achieved. The main difference between the hardwired and duplication-based modular architectures is that in the latter the modules reached a much higher degree of functional specialization of their motor control units with regard to high level behavioral functions. The hardwired architectures reach the same level of performance, but have a more distributed assignment of functional tasks to the motor control units. We conclude that the mechanism through which functional specialization is achieved is similar to the mechanism proposed for the evolution of duplicated genes. It is found that the duplication of multifunctional modules first leads to a change in the regulation of the module, leading to a differentiation of the functional context in which the module is used. Then the module adapts to the new functional context. After this second step the system is locked into a functionally specialized state. We suggest that functional specialization may be an evolutionary absorption state.

Purpose: To evaluate right ventricular (RV) uptake measured by quantitative [ 99m Tc]Tc-DPD SPECT/CT to investigate its role in predicting and evaluating prognosis and therapeutic outcomes in patients with transthyretin amyloid cardiomyopathy (ATTR-CA)., Methods: Patients with ATTR-CA were consecutively enrolled for quantitative [ 99m Tc]Tc-DPD SPECT/CT. Ventricular amyloid burden was quantified by SUV max and TBR. Differences in RV uptake (focal or diffuse) and associations with clinical characteristics and CMR data were evaluated. The primary endpoint was major adverse cardiac events (MACEs), including all-cause deaths, heart failure hospitalizations, complete atrioventricular block, sustained ventricular tachycardia, and atrial fibrillation/flutter. Prognostic associations were evaluated using Cox regression and Kaplan-Meier survival analysis. A secondary endpoint involved a longitudinal SPECT/CT analysis during Tafamidis therapy., Results: The study included 76 patients, all showing both RV and LV uptake on SPECT imaging. Compared with patients with focal RV uptake, patients with diffuse RV uptake had higher serum troponin T levels (P < 0.05), septal thickness (P < 0.01), and external cardiac circulation volume (ECV) (P < 0.05). RV uptake was correlated with septal thickness, ECV, LV uptake, NT-proBNP and troponin-T (all P < 0.05). Among 53 patients, high LV and RV uptake significantly predicted MACEs (P < 0.001), with a median follow-up time of 16 months. A subgroup of 20 patients showed significant reductions in LV and RV uptake after Tafamidis treatment (P < 0.001)., Conclusion: Increasing RV amyloid burden quantified by SPECT/CT is associated with advanced disease stage and predicts MACEs, serving as valuable markers for prognosis and treatment monitoring in ATTR-CA., Competing Interests: Declarations. Ethics approval: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the Vienna General Hospital, Medical University of Vienna Institutional Review Board (EK1557/2020) for retrospective analysis. Competing interests: All other authors have no relationships relevant to the contents of this paper to disclose., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aims: Quantification of cardiac [99mTc]-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) uptake enhances diagnostic capabilities and may facilitate prognostic stratification in patients with transthyretin cardiac amyloidosis (ATTR-CA). This study aimed to evaluate the association of quantitative left ventricular (LV) DPD uptake with myocardial structure and function, and their implications on outcome in ATTR-CA., Methods and Results: Consecutive ATTR-CA patients (n=100) undergoing planar DPD scintigraphy with Perugini grade 2 or 3, alongside quantitative DPD SPECT/CT imaging and speckle-tracking echocardiography between 2019 and 2023, were included and divided into two cohorts based on median DPD retention index (low DPD uptake: ≤5.4, n=50; high DPD uptake: >5.4, n=50). The DPD retention index showed significant, albeit weak to modest, correlations with LV global longitudinal strain (LV-GLS: r=0.366,p<0.001), right ventricular free wall longitudinal strain (RV-FW-LS: r=0.316,p=0.002), LV diastolic function (E/e' average: r=0.304, p=0.013), NT-proBNP (r=0.332,p<0.001), troponin T (r=0.233,p=0.022), 6-minute walk distance (6MWD: r=-0.222,p=0.033) and National Amyloidosis Centre (NAC) stage (r=0.294,p=0.003). ATTR-CA patients in the high DPD uptake cohort demonstrated more advanced disease severity regarding longitudinal cardiac function (LV-GLS: p=0.012, RV-FW-LS: p=0.036), LV diastolic function (E/e' average: p=0.035), cardiac biomarkers (NT-proBNP: p=0.012, troponin T: p=0.044), exercise capacity (6MWD: p=0.035) and disease stage (NAC stage I: p=0.045, III: p=0.006), and experienced adverse outcomes compared to the low DPD uptake cohort [composite endpoint: all-cause death or heart failure hospitalization, HR: 2.873 (95%CI:1.439-5.737), p=0.003; DPD retention index: adjusted HR 1.221 (95%CI: 1.078-1.383), p=0.002]., Conclusion: In ATTR-CA, enhanced quantitative LV DPD uptake indicates advanced disease severity and is associated with adverse outcome. DPD quantification may facilitate prognostic stratification when diagnosing patients with ATTR-CA., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: The pathophysiological hallmark of wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is the deposition of amyloid within the myocardium., Objectives: This study aimed to investigate associations between quantitative cardiac 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) uptake and myocardial amyloid burden, cardiac function, cardiac biomarkers, and clinical status in ATTRwt-CM., Methods: Forty ATTRwt-CM patients underwent quantitative DPD single photon emission computed tomography/computed tomography to determine the standardized uptake value (SUV) retention index, cardiac magnetic resonance imaging to determine extracellular volume (ECV) and cardiac function (RV-LS), and assessment of cardiac biomarkers (N-terminal prohormone of brain natriuretic peptide [NT-proBNP], troponin T) and clinical status (6-minute walk distance [6MWD], National Amyloidosis Centre [NAC] stage). ATTRwt-CM patients were divided into 2 cohorts based on median SUV retention index (low uptake: <5.19 mg/dL, n = 20; high uptake: ≥5.19 mg/dL, n = 20). Linear regression models were used to assess associations of the SUV retention index with variables of interest and the Mann-Whitney U or chi-squared test to compare variables between groups., Results: ATTRwt-CM patients (n = 40) were elderly (78.0 years) and predominantly male (75.0%). Univariable linear regression analyses revealed associations of the SUV retention index with ECV (r = 0.669, β = 0.139, P  < 0.001), native T1 time (r = 0.432, β = 0.020, P  = 0.005), RV-LS (r = 0.445, β = 0.204, P  = 0.004), NT-proBNP (log 10 ) (r = 0.458, β = 2.842, P  = 0.003), troponin T (r = 0.422, β = 0.048, P  = 0.007), 6MWD (r = 0.385, β = -0.007, P  = 0.017), and NAC stage (r = 0.490, β = 1.785, P  = 0.001). Cohort comparison demonstrated differences in ECV ( P  = 0.001), native T1 time ( P  = 0.013), RV-LS ( P  = 0.003), NT-proBNP ( P  < 0.001), troponin T ( P  = 0.046), 6MWD ( P  = 0.002), and NAC stage (I: P  < 0.001, II: P  = 0.030, III: P  = 0.021)., Conclusions: In ATTRwt-CM, quantitative cardiac DPD uptake correlates with myocardial amyloid load, longitudinal cardiac function, cardiac biomarkers, exercise capacity, and disease stage, providing a valuable tool to quantify and monitor cardiac disease burden., Competing Interests: Dr Rettl has received speaker fees and congress support from Akcea Therapeutics, Alnylam Pharmaceuticals, and Pfizer Inc, as well as research grants from 10.13039/100004319Pfizer Inc. Dr Duca has received speaker fees and congress support from 10.13039/501100015086AOP Orphan Pharmaceuticals GmbH, 10.13039/100006400Alnylam Pharmaceuticals, 10.13039/100004326Bayer AG, 10.13039/100004336Novartis AG, 10.13039/100004319Pfizer Inc and, as well as research grants from the 10.13039/501100015797Austrian Society of Cardiology and 10.13039/100004319Pfizer Inc. Dr Beitzke has received speaker fees from GE Healthcare and Siemens. Dr Nitsche receives speaker fees and research grants from 10.13039/100004319Pfizer Inc. Dr Badr Eslam has received speaker fees from Merck Sharp & Dohme Ges.m.b.H., AOP Orphan Pharmaceuticals GmbH, and OrphaCare GmbH, as well as research grants from OrphaCare GmbH and Astra Zeneca GmbH. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2024 The Authors.)

Background: The diagnosis of cardiac amyloidosis can be established non-invasively by scintigraphy using bone-avid tracers, but visual assessment is subjective and can lead to misdiagnosis. We aimed to develop and validate an artificial intelligence (AI) system for standardised and reliable screening of cardiac amyloidosis-suggestive uptake and assess its prognostic value, using a multinational database of 99m Tc-scintigraphy data across multiple tracers and scanners., Methods: In this retrospective, international, multicentre, cross-tracer development and validation study, 16 241 patients with 19 401 scans were included from nine centres: one hospital in Austria (consecutive recruitment Jan 4, 2010, to Aug 19, 2020), five hospital sites in London, UK (consecutive recruitment Oct 1, 2014, to Sept 29, 2022), two centres in China (selected scans from Jan 1, 2021, to Oct 31, 2022), and one centre in Italy (selected scans from Jan 1, 2011, to May 23, 2023). The dataset included all patients referred to whole-body 99m Tc-scintigraphy with an anterior view and all 99m Tc-labelled tracers currently used to identify cardiac amyloidosis-suggestive uptake. Exclusion criteria were image acquisition at less than 2 h ( 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic acid, 99m Tc-hydroxymethylene diphosphonate, and 99m Tc-methylene diphosphonate) or less than 1 h ( 99m Tc-pyrophosphate) after tracer injection and if patients' imaging and clinical data could not be linked. Ground truth annotation was derived from centralised core-lab consensus reading of at least three independent experts (CN, TT-W, and JN). An AI system for detection of cardiac amyloidosis-associated high-grade cardiac tracer uptake was developed using data from one centre (Austria) and independently validated in the remaining centres. A multicase, multireader study and a medical algorithmic audit were conducted to assess clinician performance compared with AI and to evaluate and correct failure modes. The system's prognostic value in predicting mortality was tested in the consecutively recruited cohorts using cox proportional hazards models for each cohort individually and for the combined cohorts., Findings: The prevalence of cases positive for cardiac amyloidosis-suggestive uptake was 142 (2%) of 9176 patients in the Austrian, 125 (2%) of 6763 patients in the UK, 63 (62%) of 102 patients in the Chinese, and 103 (52%) of 200 patients in the Italian cohorts. In the Austrian cohort, cross-validation performance showed an area under the curve (AUC) of 1·000 (95% CI 1·000-1·000). Independent validation yielded AUCs of 0·997 (0·993-0·999) for the UK, 0·925 (0·871-0·971) for the Chinese, and 1·000 (0·999-1·000) for the Italian cohorts. In the multicase multireader study, five physicians disagreed in 22 (11%) of 200 cases (Fleiss' kappa 0·89), with a mean AUC of 0·946 (95% CI 0·924-0·967), which was inferior to AI (AUC 0·997 [0·991-1·000], p=0·0040). The medical algorithmic audit demonstrated the system's robustness across demographic factors, tracers, scanners, and centres. The AI's predictions were independently prognostic for overall mortality (adjusted hazard ratio 1·44 [95% CI 1·19-1·74], p<0·0001)., Interpretation: AI-based screening of cardiac amyloidosis-suggestive uptake in patients undergoing scintigraphy was reliable, eliminated inter-rater variability, and portended prognostic value, with potential implications for identification, referral, and management pathways., Funding: Pfizer., Competing Interests: Declaration of interests CN reports speaker fees or institutional research grants from Pfizer and advisory board honoraria from Prothena. TAT is co-founder and shareholder of Myocardium AI. RHD has received payment for consultancy work and owns shares in Myocardium AI. All other authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Aims: Novel ribonucleic acid interference (RNAi) therapeutics such as patisiran and inotersen have been shown to benefit neurologic disease course and quality of life in patients with hereditary transthyretin amyloidosis (ATTRv). We aimed to determine the impact of RNAi therapeutics on myocardial amyloid load using quantitative single photon emission computed tomography/computed tomography (SPECT/CT) imaging in patients with ATTRv-related cardiomyopathy (ATTRv-CM). We furthermore compared them with wild-type ATTR-CM (ATTRwt-CM) patients treated with tafamidis. Methods and results: ATTRv-CM patients underwent [ 99m Tc]-radiolabeled diphosphono-1,2-propanodicarboxylic acid ( 99m Tc-DPD) scintigraphy and quantitative SPECT/CT imaging before and after 12 months (IQR: 11.0-12.0) of treatment with RNAi therapeutics (patisiran: n  = 5, inotersen: n  = 4). RNAi treatment significantly reduced quantitative myocardial uptake as measured by standardised uptake value (SUV) retention index (baseline: 5.09 g/mL vs. follow-up: 3.19 g/mL, p  = .028) in ATTRv-CM patients without significant improvement in cardiac function. Tafamidis treatment resulted in a significant reduction in SUV retention index (4.96 g/mL vs. 3.27 g/mL, p  < .001) in ATTRwt-CM patients (historical control cohort: n  = 40) at follow-up [9.0 months (IQR: 7.0-10.0)] without beneficial impact on cardiac function. Conclusions: RNAi therapeutics significantly reduce quantitative myocardial uptake in ATTRv-CM patients, comparable to tafamidis treatment in ATTRwt-CM patients, without impact on cardiac function. Serial 99m Tc-DPD SPECT/CT imaging may be a valuable tool to quantify and monitor response to disease-specific therapies in both ATTRv-CM and ATTRwt-CM.

Background: Immune checkpoint inhibitors (ICI) are one of the most effective therapies in oncology, albeit associated with various immune-related adverse events also affecting the cardiovascular system., Methods: We aimed to investigate the effect of ICI on arterial 2-[ 18 F]FDG uptake by using 2-[ 18 F]FDG PET/CT imaging pre/post treatment in 47 patients with lung cancer. Maximum 2-[ 18 F]FDG standardized uptake values (SUVmax) and target-to-background ratios (TBRs) were calculated along six arterial segments. We classified the arterial PET lesions by pre-existing active inflammation (cut-off: TBRpre ≥ 1.6). 2-[ 18 F]FDG metabolic activity pre/post treatment was also quantified in bone marrow, spleen, and liver. Circulating blood biomarkers were additionally collected at baseline and after immunotherapy., Results: ICI treatment resulted in significantly increased arterial inflammatory activity, detected by increased TBRs, in all arterial PET lesions analyzed. In particular, a significant elevation of arterial 2-[ 18 F]FDG uptake was only recorded in PET lesions without pre-existing inflammation, in calcified as well as in non-calcified lesions. Furthermore, a significant increase in arterial 2-[ 18 F]FDG metabolic activity after immunotherapy was solely observed in patients not previously treated with chemotherapy or radiotherapy as well as in those without CV risk factors. No significant changes were recorded in either 2-[ 18 F]FDG uptake of bone marrow, spleen and liver after treatment, or the blood biomarkers., Conclusions: ICI induces vascular inflammation in lung cancer patients lacking pre-existing arterial inflammation.

Receptor tyrosine kinases, or RTKs, are one large family of cell surface receptors involved in signal transduction, which represent an integral part of the signaling pathways. They play a crucial role in most important cellular processes, starting with the cell cycle, proliferation and differentiation, as well as cell migration, metabolism and survival. The introduction of ImmunoPET evaluating the expression of RTKs by specific monoclonal antibodies (mAbs) or antibody fragments is regarded as a promising tool for imaging treatment efficacy and developing anticancer therapeutics. Our review focuses mainly on the current clinical research regarding ImmunoPET targeting RTKs, with particular interest in the epidermal growth factor family, or HER family, and vascular endothelial-derived growth factor/receptor.

In the last decade, monoclonal antibodies (mAbs) targeting CTLA-4, PD-1, or PD-L1 have been developed and immune checkpoint inhibitors (ICIs) have become the main approach in cancer immunotherapy. However, not all patients benefit from ICI therapy and some are at risk of developing treatment-induced side-effects. These aspects, in parallel with the imaging challenges related to response assessments during immunotherapy, have driven scientific research to the discovery of new predictive biomarkers to individualize patients who could benefit from ICIs. In this context, molecular imaging using PET (positron emission tomography), which allows for whole-body tumor visualization, may be a promising non-invasive method for the determination of patients' sensitivity to antibody drugs. Several PET tracers, diverse from 2-[ 18 F]FDG (or 2-Deoxy-2-[ 18 F]fluoroglucose), have been developed to image immune checkpoints (ICs) or key elements of the immune system, although most of them are still in preclinical phases. Herein, we present the current state of the ImmunoPET-targeting of IC proteins with mAbs and antibody fragments, with a main focus on the latest developments in clinical molecular imaging studies of solid tumors. Moreover, given the relevance of the immune system and of tumor-infiltrating lymphocytes in particular in the prediction of the benefit of ICIs, we dedicate a portion of this review to ImmunoPET-targeting T cells.

The prevalence of cardiac amyloidosis (CA) in the general population and associated prognostic implications remain poorly understood. We aimed to identify CA prevalence and outcomes in bone scintigraphy referrals. Methods: Consecutive all-comers undergoing 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic-acid ( 99m Tc-DPD) bone scintigraphy between 2010 and 2020 were included. Perugini grade 1 was defined as low-grade uptake and grade 2 or 3 as confirmed CA. All-cause mortality, cardiovascular death, and heart failure hospitalization (HHF) served as endpoints. Results: In total, 17,387 scans from 11,527 subjects (age, 61 ± 16 y; 63.0% women, 73.6% cancer) were analyzed. Prevalence of 99m Tc-DPD positivity was 3.3% ( n = 376/11,527; grade 1: 1.8%, grade 2 or 3: 1.5%), and was higher among cardiac than noncardiac referrals (18.2% vs. 1.7%). In individuals with more than 1 scan, progression from grade 1 to grade 2 or 3 was observed. Among patients with biopsy-proven CA, the portion of light-chain (AL)-CA was significantly higher in grade 1 than grade 2 or 3 (73.3% vs. 15.4%). After a median of 6 y, clinical event rates were: 29.4% mortality, 2.6% cardiovascular death, and 1.5% HHF, all independently predicted by positive 99m Tc-DPD. Overall, adverse outcomes were driven by confirmed CA (vs. grade 0, mortality: adjusted hazard ratio [AHR] 1.46 [95% CI 1.12-1.90]; cardiovascular death: AHR 2.34 [95% CI 1.49-3.68]; HHF: AHR 2.25 [95% CI 1.51-3.37]). One-year mortality was substantially higher in cancer than noncancer patients. Among noncancer patients, also grade 1 had worse outcomes than grade 0 (HHF/death: AHR 1.45 [95% CI 1.01-2.09]), presumably because of longer observation and higher prognostic impact of early infiltration. Conclusion: Positive 99m Tc-DPD was identified in a substantial number of consecutive 99m Tc-DPD referrals and associated with adverse outcomes., (© 2022 by the Society of Nuclear Medicine and Molecular Imaging.)

Cardiac amyloidosis (CA) is a heterogeneous group of diseases in which extracellular insoluble amyloid proteins are deposited in specific organs and tissues locally or systemically, thereby interfering with physiological function. Transthyretin protein (TTR) and light chain (AL) amyloidosis are the most common types of cardiac amyloidosis. Radionuclide bone scintigraphy has recently become the most common non-invasive test for the diagnosis of TTR-CA but is of limited value for the diagnosis of AL-CA. PET has proved promising for the diagnosis of CA and its applications are expected to expand in the future. This review summarizes the current bone scintigraphy and amyloid-targeting Positron emission tomography (PET) imaging, the binding imaging properties of radiotracers, and the values of diagnosis, prognosis, and monitoring therapy response in CA.

Background: Mitral regurgitation (MR) and cardiac amyloidosis (CA) both primarily affect older patients. Data on coexistence and prognostic implications of MR and CA are currently lacking., Objectives: This study sought to identify the prevalence, clinical characteristics, and outcomes of MR CA compared with lone MR., Methods: Consecutive patients undergoing transcatheter edge-to-edge repair (TEER) for MR at 2 sites were screened for concomitant CA using a multiparametric approach including core laboratory 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic acid bone scintigraphy and echocardiography and immunoglobulin light chain assessment. Transthyretin CA (ATTR) was diagnosed by 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic acid (Perugini grade 1: early infiltration; grades 2/3: clinical CA) and the absence of monoclonal protein, and light chain (AL) CA via tissue biopsy. All-cause mortality and hospitalization for heart failure (HHF) served as the endpoints., Results: A total of 120 patients (age 76.9 ± 8.1 years, 55.8% male) were recruited. Clinical CA was diagnosed in 14 patients (11.7%; 12 ATTR, 1 AL, and 1 combined ATTR/AL) and early amyloid infiltration in 9 patients (7.5%). Independent predictors of MR CA were increased posterior wall thickness and the presence of a left anterior fascicular block on electrocardiography. Procedural success and periprocedural complications of TEER were similar in MR CA and lone MR (P for all = NS). After a median of 1.7 years, 25.8% had experienced death and/or HHF. MR CA had worse outcomes compared with lone MR (HR: 2.2; 95% CI: 1.0-4.7; P = 0.034), driven by a 2.5-fold higher risk for HHF (HR: 2.5; 95% CI: 1.1-5.9), but comparable mortality (HR: 1.6; 95% CI: 0.4-6.1)., Conclusions: Dual pathology of MR CA is common in elderly patients with MR undergoing TEER and has worse postinterventional outcomes compared with lone MR., Competing Interests: Funding Support and Author Disclosures This study received financial support from Pfizer. The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2022 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)