Secondary Prevention and Extreme Cardiovascular Risk Evaluation (SEVERE-1), Focus on Prevalence and Associated Risk Factors: The Study Protocol

INTRODUCTION

Despite significant improvement in secondary CardioVascular (CV) preventive strategies, some acute and chronic coronary syndrome (ACS and CCS) patients will suffer recurrent events (also called "extreme CV risk"). Recently new biochemical markers, such as uric acid (UA), lipoprotein A [Lp(a)] and several markers of inflammation, have been described to be associated with CV events recurrence. The SEcondary preVention and Extreme cardiovascular Risk Evaluation (SEVERE-1) study will accurately characterize extreme CV risk patients enrolled in cardiac rehabilitation (CR) programs.

AIM

 Our aims will be to describe the prevalence of extreme CV risk and its association with newly described biochemical CV risk factors.

AIM

Our aims will be to describe the prevalence of extreme CV risk and its association with newly described biochemical CV risk factors.

METHODS

We will prospectively enrol 730 ACS/CCS patients at the beginning of a CR program. Extreme CV risk will be retrospectively defined as the presence of a previous (within 2 years) CV events in the patients' clinical history. UA, Lp(a) and inflammatory markers (interleukin-6 and -18, tumor necrosis factor alpha, C-reactive protein, calprotectin and osteoprotegerin) will be assessed in ACS/CCS patients with extreme CV risk and compared with those without extreme CV risk but also with two control groups: 1180 hypertensives and 765 healthy subjects. The association between these biomarkers and extreme CV risk will be assessed with a multivariable model and two scoring systems will be created for an accurate identification of extreme CV risk patients. The first one will use only clinical variables while the second one will introduce the biochemical markers. Finally, by exome sequencing we will both evaluate polygenic risk score ability to predict recurrent events and perform mendellian randomization analysis on CV biomarkers.

CONCLUSIONS

Our study proposal was granted by the European Union PNRR M6/C2 call. With this study we will give definitive data on extreme CV risk prevalence rising attention on this condition and leading cardiologist to do a better diagnosis and to carry out a more intensive treatment optimization that will finally leads to a reduction of future ACS recurrence. This will be even more important for cardiologists working in CR that is a very important place for CV risk definition and therapies refinement.

Serological response and breakthrough infection after COVID-19 vaccination in patients with cirrhosis and post-liver transplant

BACKGROUND

Vaccine hesitancy and lack of access remain major issues in disseminating COVID-19 vaccination to liver patients globally. Factors predicting poor response to vaccination and risk of breakthrough infection are important data to target booster vaccine programs. The primary aim of the current study was to measure humoral responses to 2 doses of COVID-19 vaccine. Secondary aims included the determination of factors predicting breakthrough infection.

METHODS

COVID-19 vaccination and Biomarkers in cirrhosis And post-Liver Transplantation is a prospective, multicenter, observational case-control study. Participants were recruited at 4-10 weeks following first and second vaccine doses in cirrhosis [n = 325; 94% messenger RNA (mRNA) and 6% viral vaccine], autoimmune liver disease (AILD) (n = 120; 77% mRNA and 23% viral vaccine), post-liver transplant (LT) (n = 146; 96% mRNA and 3% viral vaccine), and healthy controls (n = 51; 72% mRNA, 24% viral and 4% heterologous combination). Serological end points were measured, and data regarding breakthrough SARS-CoV-2 infection were collected.

RESULTS

After adjusting by age, sex, and time of sample collection, anti-Spike IgG levels were the lowest in post-LT patients compared to cirrhosis (p < 0.0001), AILD (p < 0.0001), and control (p = 0.002). Factors predicting reduced responses included older age, Child-Turcotte-Pugh B/C, and elevated IL-6 in cirrhosis; non-mRNA vaccine in AILD; and coronary artery disease, use of mycophenolate and dysregulated B-call activating factor, and lymphotoxin-α levels in LT. Incident infection occurred in 6.6%, 10.6%, 7.4%, and 15.6% of cirrhosis, AILD, post-LT, and control, respectively. The only independent factor predicting infection in cirrhosis was low albumin level.

CONCLUSIONS

LT patients present the lowest response to the SARS-CoV-2 vaccine. In cirrhosis, the reduced response is associated with older age, stage of liver disease and systemic inflammation, and breakthrough infection with low albumin level.

The Association between Dysnatraemia during Hospitalisation and Post-COVID-19 Mental Fatigue

COVID-19 may induce short- and long-term cognitive failures after recovery, but the underlying risk factors are still controversial. Here, we investigated whether (i) the odds of experiencing persistent cognitive failures differ based on the patients' disease course severity and sex at birth; and (ii) the patients' electrolytic profile in the acute stage represents a risk factor for persistent cognitive failures. We analysed data from 204 patients suffering from COVID-19 and hospitalised during the first pandemic wave. According to the 7-point WHO-OS scale, their disease course was classified as severe or mild. We investigated the presence of persistent cognitive failures collected after hospital discharge, while electrolyte profiles were collected during hospitalisation. The results showed that females who suffered from a mild course compared to a severe course of COVID-19 had a higher risk of presenting with persistent mental fatigue after recovery. Furthermore, in females who suffered from a mild course of COVID-19, persistent mental fatigue was related to electrolyte imbalance, in terms of both hypo- and hypernatremia, during hospitalisation in the acute phase. These findings have important implications for the clinical management of hospitalised COVID-19 patients. Attention should be paid to potential electrolyte imbalances, mainly in females suffering from mild COVID-19.

Role of epigenetics in the clinical evolution of COVID-19 disease. Epigenome-wide association study identifies markers of severe outcome

BACKGROUND

COVID-19 has a wide spectrum of clinical manifestations and given its impact on morbidity and mortality, there is an unmet medical need to discover endogenous cellular and molecular biomarkers that predict the expected clinical course of the disease. Recently, epigenetics and especially DNA methylation have been pointed out as a promising tool for outcome prediction in several diseases.

METHODS AND RESULTS

Using the Illumina Infinium Methylation EPIC BeadChip850K, we investigated genome-wide differences in DNA methylation in an Italian Cohort of patients with comorbidities and compared severe (n = 64) and mild (123) prognosis. Results showed that the epigenetic signature, already present at the time of Hospital admission, can significantly predict risk of severe outcomes. Further analyses provided evidence of an association between age acceleration and a severe prognosis after COVID-19 infection. The burden of Stochastic Epigenetic Mutation (SEMs) has been significantly increased in patients with poor prognosis. Results have been replicated in silico considering COVID-19 negative subjects and available previously published datasets.

CONCLUSIONS

Using original methylation data and taking advantage of already published datasets, we confirmed in the blood that epigenetics is actively involved in immune response after COVID-19 infection, allowing the identification of a specific signature able to discriminate the disease evolution. Furthermore, the study showed that epigenetic drift and age acceleration are associated with severe prognosis. All these findings prove that host epigenetics undergoes notable and specific rearrangements to respond to COVID-19 infection which can be used for a personalized, timely, and targeted management of COVID-19 patients during the first stages of hospitalization.

Obesity and Dysmetabolic Factors among Deceased COVID-19 Adults under 65 Years of Age in Italy: A Retrospective Case-Control Study

Background: Italy has witnessed high levels of COVID-19 deaths, mainly at the elderly age. We assessed the comorbidity and the biochemical profiles of consecutive patients ≤65 years of age to identify a potential risk profile for death. Methods: We retrospectively analyzed clinical data from consecutive hospitalized-for-COVID-19 patients ≤65 years, who were died (593 patients) or discharged (912 patients) during February–December 2020. Multivariate logistic regression identified the mortality risk factors. Results: Overweight (adjusted odds ratio (adjOR) 5.53, 95% CI 2.07–14.76), obesity (adjOR 8.58, CI 3.30–22.29), dyslipidemia (adjOR 10.02, 95% CI 1.06–94.22), heart disease (adjOR 17.68, 95% CI 3.80–82.18), cancer (adjOR 13.28, 95% CI 4.25–41.51) and male sex (adjOR 5.24, 95% CI 2.30–11.94) were associated with death risk in the youngest population. In the older population (46-65 years of age), the overweight and obesity were also associated with the death risk, however at a lower extent: the adjORs varyied from 1.49 to 2.36 for overweight patients and from 3.00 to 4.07 for obese patients. Diabetes was independently associated with death only in these older patients. Conclusion: Overweight, obesity and dyslipidemia had a pivotal role in increasing young individuals’ death risk. Their presence should be carefully evaluated for prevention and/or prompt management of SARS-CoV2 infection in such high-risk patients to avoid the worst outcomes.

Sex differences in electrolyte imbalances caused by SARS-CoV-2: A cross-sectional study

BACKGROUND

Since SARS-CoV-2 spread, evidence regarding sex differences in progression and prognosis of COVID-19 have emerged. Besides this, studies on patients' clinical characteristics have described electrolyte imbalances as one of the recurrent features of COVID-19.

METHODS

We performed a cross-sectional study on all patients admitted to the emergency department (ED) from 1 March to 31 May 2020 who had undergone a blood gas analysis and a nasopharyngeal swab test for SARS-CoV-2 by rtPCR. We defined positive patients as cases (n = 710) and negatives as controls (n = 619), for a total number of patients of 1.329. The study was approved by the local ethics committee Area 3 Milan. Data were automatically extracted from the hospital laboratory SQL-based repository in anonymised form. We considered as outcomes potassium (K⁺ ), sodium (Na⁺ ), chlorine (Cl^- ) and calcium (Ca⁺⁺ ) as continuous and as categorical variables, in their relation with age, sex and SARS-CoV-2 infection status.

RESULTS

We observed a higher prevalence of hypokalaemia among patients positive for SARS-CoV-2 (13.7% vs 6% of negative subjects). Positive patients had a higher probability to be admitted to the ED with hypokalaemia (OR 2.75, 95% CI 1.8-4.1, P < .0001) and women were twice as likely to be affected than men (OR 2.43, 95% CI 1.67-3.54, P < .001). Odds ratios for positive patients to manifest with an alteration in serum Na⁺ was (OR 1.6, 95% CI 1.17-2.35, P < .001) and serum chlorine (OR 1.6, 95% CI 1.03-2.69, P < .001). Notably, OR for positive patients to be hypocalcaemic was 7.2 (95% CI 4.8-10.6, P < .0001) with a low probability for women to be hypocalcaemic (OR 0.63, 95% CI 0.4-0.8, P = .005).

CONCLUSIONS

SARS-CoV-2 infection is associated with a higher prevalence of hypokalaemia, hypocalcaemia, hypochloraemia and sodium alterations. Hypokalaemia is more frequent among women and hypocalcaemia among men.

Inositol and Non-Alcoholic Fatty Liver Disease: A Systematic Review on Deficiencies and Supplementation

Liver lipid accumulation is a hallmark of non-alcoholic fatty liver disease (NAFLD), broadly associated with insulin resistance. Inositols (INS) are ubiquitous polyols implied in many physiological functions. They are produced endogenously, are present in many foods and in dietary supplements. Alterations in INS metabolism seems to play a role in diseases involving insulin resistance such as diabetes and polycystic ovary syndrome. Given its role in other metabolic syndromes, the hypothesis of an INS role as a supplement in NAFLD is intriguing. We performed a systematic review of the literature to find preclinical and clinical evidence of INS supplementation efficacy in NAFLD patients. We retrieved 10 studies on animal models assessing Myoinosiol or Pinitol deficiency or supplementation and one human randomized controlled trial (RCT). Overall, INS deficiency was associated with increased fatty liver in animals. Conversely, INS supplementation in animal models of fatty liver reduced hepatic triglycerides and cholesterol accumulation and maintained a normal ultrastructural liver histopathology. In the one included RCT, Pinitol supplementation obtained similar results. Pinitol significantly reduced liver fat, post-prandial triglycerides, AST levels, lipid peroxidation increasing glutathione peroxidase activity. These results, despite being limited, indicate the need for further evaluation of INS in NAFLD in larger clinical trials.

A hnRNP K⁻AR-Related Signature Reflects Progression toward Castration-Resistant Prostate Cancer

The major challenge in castration-resistant prostate cancer (CRPC) remains the ability to predict the clinical responses to improve patient selection for appropriate treatments. The finding that androgen deprivation therapy (ADT) induces alterations in the androgen receptor (AR) transcriptional program by AR coregulators activity in a context-dependent manner, offers the opportunity for identifying signatures discriminating different clinical states of prostate cancer (PCa) progression. Gel electrophoretic analyses combined with western blot showed that, in androgen-dependent PCa and CRPC in vitro models, the subcellular distribution of spliced and serine-phosphorylated heterogeneous nuclear ribonucleoprotein K (hnRNP K) isoforms can be associated with different AR activities. Using mass spectrometry and bioinformatic analyses, we showed that the protein sets of androgen-dependent (LNCaP) and ADT-resistant cell lines (PDB and MDB) co-immunoprecipitated with hnRNP K varied depending on the cell type, unravelling a dynamic relationship between hnRNP K and AR during PCa progression to CRPC. By comparing the interactome of LNCaP, PDB, and MDB cell lines, we identified 51 proteins differentially interacting with hnRNP K, among which KLK3, SORD, SPON2, IMPDH2, ACTN4, ATP1B1, HSPB1, and KHDRBS1 were associated with AR and differentially expressed in normal and tumor human prostate tissues. This hnRNP K–AR-related signature, associated with androgen sensitivity and PCa progression, may help clinicians to better manage patients with CRPC.

Recent Applications of the Sentinel Lymph Node Concept: Preliminary Experience in Prostate Cancer

Aims and Background

Following the widespread use of radioguided surgery (RGS) in melanoma and breast cancer, we applied this new surgical strategy to prostate cancer (PC). The aims of this study were 1) to evaluate the accuracy of RGS in the detection of prostatic sentinel lymph nodes (SLN), and 2) to verify if pelvic lymphadenectomy (LAD) is an accurate means to detect solitary micrometastases.

Study design

We investigated 48 patients with PC confirmed by transrectal biopsy who underwent radical prostatectomy and bilateral LAD. A dose of 99mTc-labeled nanocolloid particles was injected into the prostate after needle positioning by ultrasonography. Serial imaging was obtained with a gamma camera, identifying 1) the first radioactive lymph node (sentinel lymph node, SLN); 2) other radioactive lymph nodes, and 3) non-active lymph nodes.

Results

Forty-three SLNs were identified in 48 patients. Twenty SLNs were located at unusual sites with respect to the extent of conventional LAD. Five SLNs were positive for micrometastases and two of these were located outside the usual LAD area. No micrometastases were found in any of the remaining lymph nodes (active and non-active).

Conclusions

These preliminary results are in agreement with the few previous scientific contributions available on this topic and indicate that it is possible to reduce the extent and duration of surgery and necessary to reevaluate the conventional sites of lymphatic drainage.

Proteomic analysis uncovers common effects of IFN-γ and IL-27 on the HLA class I antigen presentation machinery in human cancer cells

IL-27, a member of the IL-12-family of cytokines, has shown anti-tumor activity in several pre-clinical models due to anti-proliferative, anti-angiogenic and immune-enhancing effects. On the other hand, IL-27 demonstrated immune regulatory activities and inhibition of auto-immunity in mouse models. Also, we reported that IL-27, similar to IFN-γ, induces the expression of IL-18BP, IDO and PD-L1 immune regulatory molecules in human cancer cells. Here, a proteomic analysis reveals that IL-27 and IFN-γ display a broad overlap of functions on human ovarian cancer cells. Indeed, among 990 proteins modulated by either cytokine treatment in SKOV3 cells, 814 showed a concordant modulation by both cytokines, while a smaller number (176) were differentially modulated. The most up-regulated proteins were common to both IFN-γ and IL-27. In addition, functional analysis of IL-27-regulated protein networks highlighted pathways of interferon signaling and regulation, antigen presentation, protection from natural killer cell-mediated cytotoxicity, regulation of protein polyubiquitination and proteasome, aminoacid catabolism and regulation of viral protein levels.

Importantly, we found that IL-27 induced HLA class I molecule expression in human cancer cells of different histotypes, including tumor cells showing very low expression. IL-27 failed only in a cancer cell line bearing a homozygous deletion in the B2M gene. Altogether, these data point out to a broad set of activities shared by IL-27 and IFN-γ, which are dependent on the common activation of the STAT1 pathway. These data add further explanation to the anti-tumor activity of IL-27 and also to its dual role in immune regulation.

Adaptive phenotype drives resistance to androgen deprivation therapy in prostate cancer

Background

Prostate cancer (PCa), the second most common cancer affecting men worldwide, shows a broad spectrum of biological and clinical behaviour representing the epiphenomenon of an extreme heterogeneity. Androgen deprivation therapy is the mainstay of treatment for advanced forms but after few years the majority of patients progress to castration-resistant prostate cancer (CRPC), a lethal form that poses considerable therapeutic challenges.

Methods

Western blotting, immunocytochemistry, invasion and reporter assays, and in vivo studies were performed to characterize androgen resistant sublines phenotype in comparison to the parental cell line LNCaP. RNA microarray, mass spectrometry, integrative transcriptomic and proteomic differential analysis coupled with GeneOntology and multivariate analyses were applied to identify deregulated genes and proteins involved in CRPC evolution.

Results

Treating the androgen-responsive LNCaP cell line for over a year with 10 μM bicalutamide both in the presence and absence of 0.1 nM 5-α-dihydrotestosterone (DHT) we obtained two cell sublines, designated PDB and MDB respectively, presenting several analogies with CRPC. Molecular and functional analyses of PDB and MDB, compared to the parental cell line, showed that both resistant cell lines were PSA low/negative with comparable levels of nuclear androgen receptor devoid of activity due to altered phosphorylation; cell growth and survival were dependent on AKT and p38MAPK activation and PARP-1 overexpression; their malignant phenotype increased both in vitro and in vivo. Performing bioinformatic analyses we highlighted biological processes related to environmental and stress adaptation supporting cell survival and growth. We identified 15 proteins that could direct androgen-resistance acquisition. Eleven out of these 15 proteins were closely related to biological processes involved in PCa progression.

Conclusions

Our models suggest that environmental factors and epigenetic modulation can activate processes of phenotypic adaptation driving drug-resistance. The identified key proteins of these adaptive phenotypes could be eligible targets for innovative therapies as well as molecules of prognostic and predictive value.

Electronic supplementary material

The online version of this article (10.1186/s12964-017-0206-x) contains supplementary material, which is available to authorized users.

Proteomic Analysis of Neuroblastoma-Derived Exosomes: New Insights into a Metastatic Signature

Neuroblastoma (NB) is the most common extracranial pediatric solid tumor. Around 70% of patients with metastatic disease at diagnosis present bone-marrow infiltration, which is considered a marker of poor outcome; however, the mechanism underlying this specific tropism has to be elucidated. Tumor-derived exosomes may support metastatic progression in several tumors by interacting with the microenvironment, and may serve as tumor biomarkers. The main objective of this study is to identify an exosomal signature associated with NB metastatic bone-marrow dissemination. Therefore, the proteomic cargo of exosomes isolated from NB cell lines derived from primary tumor and bone-marrow metastasis is characterized. The comparison among exosomal proteins show 15 proteins exclusively present in primary tumor-derived exosomes, mainly involved in neuronal development, and 6 proteins in metastasis-derived exosomes related to cancer progression. Significant proteins obtain with statistical analysis performed between the two groups, reveal that primary tumor exosomes contain a higher level of proteins involved in extra-cellular matrix (ECM) assembly and adhesion, as well as in neuronal development. Exosomes isolated from bone-marrow metastasis exhibit proteins involved in ameboidal cell migration and mitochondrial activity. This work suggests that proteomic profiling of NB-derived exosomes reflects the tumor stage and may be considered as potential tumor biomarker.

Zoledronic acid boosts γδ T-cell activity in children receiving αβ+ T and CD19+ cell-depleted grafts from an HLA-haplo-identical donor

We demonstrated that γδ T cells of patients given HLA-haploidentical HSCT after removal of αβ⁺ T cells and CD19⁺ B cells are endowed with the capacity of killing leukemia cells after ex vivo treatment with zoledronic acid (ZOL). Thus, we tested the hypothesis that infusion of ZOL in patients receiving this type of graft may enhance γδ T-cell cytotoxic activity against leukemia cells. ZOL was infused every 28 d in 43 patients; most were treated at least twice. γδ T cells before and after ZOL treatments were studied in 33 of these 43 patients, till at least 7 mo after HSCT by high-resolution mass spectrometry, flow-cytometry, and degranulation assay. An induction of Vδ2-cell differentiation, paralleled by increased cytotoxicity of both Vδ1 and Vδ2 cells against primary leukemia blasts was associated with ZOL treatment. Cytotoxic activity was further increased in Vδ2 cells, but not in Vδ1 lymphocytes in those patients given more than one treatment. Proteomic analysis of γδ T cells purified from patients showed upregulation of proteins involved in activation processes and immune response, paralleled by downregulation of proteins involved in proliferation. Moreover, a proteomic signature was identified for each ZOL treatment. Patients given three or more ZOL infusions had a better probability of survival in comparison to those given one or two treatments (86% vs. 54%, respectively, p = 0.008). Our data indicate that ZOL infusion in pediatric recipients of αβ T- and B-cell-depleted HLA-haploidentical HSCT promotes γδ T-cell differentiation and cytotoxicity and may influence the outcome of patients.

Human urinary exosome proteome unveils its aerobic respiratory ability

Exosomes are 40-100-nm vesicles released by most cell types after fusion of multivesicular endosomes with the plasma membrane. Exosomes, ubiquitary in body fluids including urines, contain proteins and RNA species specific of the tissue of origin. Exosomes from urine have been extensively studied as a promising reservoir for disease biomarkers. Here, we report the proteome analysis of urinary exosomes compared to urinoma, studied by Orbitrap mass spectrometry. A discovery approach was utilized on the sample. 3429 proteins were present, with minimal overlapping among exosome and urinoma. 959 proteins (28%) in exosome and 1478 proteins (43%) in urinoma were exclusively present in only one group. By cytoscape analysis, the biological process gene ontology was correlated to their probability (P ≤ 0.05) to be functional. This was never studied before and showed a significant clustering around metabolic functions, in particular to aerobic ATP production. Urinary exosomes carry out oxidative phosphorylation, being able to synthesize ATP and consume oxygen. A previously unsuspected function emerges for human urinary exosomes as bioactive vesicles that consume oxygen to aerobically synthesize ATP. Determination of normal human urine proteome can help generate the healthy urinary protein database for comparison, useful for various renal diseases.

BIOLOGICAL SIGNIFICANCE

The findings reported represent a significant advance in the understanding of the healthy human urinary proteome. The methodology utilized to analyze the collection of proteomic data allowed the assessment of the unique composition of urinary exosomes with respect to urinoma and to elucidate the presence in the former of molecular pathways previously unknown. The paper has the potential to impact its field of research, due to the biological relevance of the metabolic capacity of urinary exosomes, which may represent their important general feature.

Abstract 1149: Consistency between genomic and proteomic profiles reveals novel molecular mechanisms of fasting antitumor activity

Background/Aim

Fasting or Short term Starvation (STS) represents a novel therapeutic strategy which appears to: i) protect normal but not tumor cells against the chemotherapy-mediated cytotoxicity, ii) induce a potent chemosensitizing effect in a wide range of experimental tumor model, and iii) be feasible, safe and able to reduce common side effects induced by chemotherapy in cancer patients. In addition, fasting alone has been shown to retard in vitro and in vivo tumor growth. However, the molecular mechanisms coupling STS with antitumor activity remain only partially understood. Thus, aim of this study is to investigate the modulation of the genomic and proteomic profiles by fasting in cancer cells with particular attention to elements involved in cell growth and metabolism signaling pathways.

Methods

Tumor cell lines were cultured under control (glucose: 1 g/L + 10% fetal bovine serum) or starved (glucose: 0.5 g/L + 1% fetal bovine serum) conditions for 48 hours. The in vitro viability of STS was tested by Trypan Blue staining and Annexin V apoptosis assay. Tumor cell proliferation was evaluated by 5-bromo-2-deoxyuridine (BrdU) and Carboxyfluorescein Succinimidyl ester (CFSE) staining. Gene expression was tested by microarray analysis. Protein expression were studied by western blot and Label Free Quantitation (LFQ) on High Resolution/Mass Accuracy Liquid Chromatography Tandem Mass Spectrometry (HR/MA LC MS/MS). Proteomic data were evaluated by network analysis using Cytoscape.

Results

In vitro experiments showed that STS significantly reduced cell proliferation and promoted apoptosis. The latter effect was mediated by a fine regulation of genes and proteins involved in cell growth and metabolic signaling pathways. In particular, STS significantly reduced the expression of elements of PI3K/AKT pathway and glycolytic enzymes. This latter modulation likely occurred at the transcriptional level since the expression profiles of STS treated cells showed a clear down-regulation of the genes encoding these enzymes as compared to untreated controls. STS also down-regulated glutaminase both at the mRNA and protein level. In contrast, proteomic and genomic analyses of the expression of oxidative phosphorylation enzymes did not show a clear up-regulation effect by STS. Finally, preliminary data revealed that STS modulates genes and proteins involved in Jak/STAT, MAPK pathways and ubiquitin mediated proteolysis. Noteworthy, for 90% of genes down- or up-regulated by STS for which a protein was identified by HR/MA LC MS/MS, a corresponding mRNA level was modulated by STS with a similar trend.

Conclusions

Taken together, the genomic and proteomic profiles demonstrated that STS caused an anti-Warburg effect and downregulated proliferation and inflammatory pathways. These findings open a novel scenario in cancer treatment.

Citation Format: Lizzia Raffaghello, Giovanna Bianchi, Roberto Martella, Danilo Marimpietri, Andrea Petretto, Elvira Inglese, Adriana Amaro, Vito Pistoia, Ulrich Pfeffer, Valter Longo. Consistency between genomic and proteomic profiles reveals novel molecular mechanisms of fasting antitumor activity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1149. doi:10.1158/1538-7445.AM2015-1149

From hundreds to thousands: Widening the normal human Urinome

The limits on protein detection in urine are unknown. Improving the analytical approach to detection would increase the number of identified proteins and potentially strengthen their predictive potential in diseases.

Here, we present the data that resulted from a combination of analytical procedures for maximizing sensitivity and reproducibility of normal human urinary proteome analysis. These procedures are ultracentrifugation, vesicle separation, combinatorial peptide ligand libraries (CPLL) and solvent removal of pigments. Proteins were identified by an Orbitrap Velos Mass Spectrometry. 3429 proteins are characterized, 1724 of which are novel discoveries.

The data are related to Santucci et al. (in press) [1] and available both here and at ChorusProject.org under project name “From hundreds to thousands: widening the normal human Urinome”. The material supplied to Chorus Progect.org includes technical MS spectra data only.

Reproducibility and variability of global and regional dyssynchrony parameters derived from phase analysis of gated myocardial perfusion SPECT

AIM

The aim of the study was to assess the reproducibility (R) and variability of quantitative parameters derived from Cedars-Sinai QGS software for phase analysis of G-SPECT in 39 coronary artery disease (CAD) patients with or without severe heart-failure (HF).

METHODS

Phase standard deviation (s) and entropy (e) are global parameters that quantify dyssynchrony. Regional measures of dyssynchrony were also computed including differences between the lateral wall versus the septal wall (DmW) and differences between the averages of midventricular lateral versus midventricular septal segments (DmS).

RESULTS

Global parameters e and s and regional parameters DmW and DmS exhibit excellent values of R=0.92, 0.99, 0.99 and 0.96, respectively. In regional parameters DmW and DmS there is a significant variability in individual scoring assessed by a standard error of measurement of =9.17 and 21.7, respectively. The box plots of e in patients with or without HF do not show any significant superimposition, while the box plots of s and DmW show a partial overlap mainly due to the significant variability of s and DmW within patients with HF. Conversely the box plots of DmS in patients with or without HF show a significant overlap due to the great variability of DmS within patients with HF.

CONCLUSION

Regional parameters derived from phase analysis of G-SPECT studies are not useful in the individual assessment of dyssynchrony in CAD patients either due to large variability in individual scoring and to a large heterogeneity in HF patients. Global parameters (e and s) exhibit both an excellent reproducibility. Nonetheless, e seems to perform better than s in individual assessment of dyssynchrony due to a better separation between HF and non HF patients. Using the QGS software approach no manual intervention is necessary to ensure a good reproducibility of global parameters.

The effect of activity outside the field of view on image quality for a 3D LSO-based whole body PET/CT scanner

The purpose of this study was to quantify the influence of outside field of view (FOV) activity concentration (A(c)(,out)) on the noise equivalent count rate (NECR), scatter fraction (SF) and image quality of a 3D LSO whole-body PET/CT scanner. The contrast-to-noise ratio (CNR) was the figure of merit used to characterize the image quality of PET scans. A modified International Electrotechnical Commission (IEC) phantom was used to obtain SF and counting rates similar to those found in average patients. A scatter phantom was positioned at the end of the modified IEC phantom to simulate an activity that extends beyond the scanner. The modified IEC phantom was filled with (18)F (11 kBq mL(-1)) and the spherical targets, with internal diameter (ID) ranging from 10 to 37 mm, had a target-to-background ratio of 10. PET images were acquired with background activity concentrations into the FOV (A(c)(,bkg)) about 11, 9.2, 6.6, 5.2 and 3.5 kBq mL(-1). The emission scan duration (ESD) was set to 1, 2, 3 and 4 min. The tube inside the scatter phantom was filled with activities to provide A(c)(,out) in the whole scatter phantom of zero, half, unity, twofold and fourfold the one of the modified IEC phantom. Plots of CNR versus the various parameters are provided. Multiple linear regression was employed to study the effects of A(c)(,out) on CNR, adjusted for the presence of variables (sphere ID, A(c)(,bkg) and ESD) related to CNR. The presence of outside FOV activity at the same concentration as the one inside the FOV reduces peak NECR of 30%. The increase in SF is marginal (1.2%). CNR diminishes significantly with increasing outside FOV activity, in the range explored. ESD and A(c)(,out) have a similar weight in accounting for CNR variance. Thus, an experimental law that adjusts the scan duration to the outside FOV activity can be devised. Recovery of CNR loss due to an elevated A(c)(,out) activity seems feasible by modulating the ESD in individual bed positions according to A(c)(,out).

Threshold segmentation for PET target volume delineation in radiation treatment planning: the role of target-to-background ratio and target size

A multivariable approach was adopted to study the dependence of the percentage threshold [TH(%)] used to define the boundaries of 18F-FDG positive tissue on emission scan duration (ESD) and activity at the start of acquisition (Aacq) for different target sizes and target-to-background (T/B) ratios. An anthropomorphic model, at least for counting rate characteristics, was used to study this dependence in conditions resembling the ones that can be encountered in the clinical studies. An annular ring of water bags of 3 cm thickness was fitted over an International Electro-technical Commission (IEC) phantom in order to obtain counting rates similar to those found in average patients. The scatter fraction of the modified IEC phantom was similar to the mean scatter fraction measured on patients, with a similar scanner. A supplemental set of microhollow spheres was positioned inside the phantom. The NEMA NU 2-2001 scatter phantom was positioned at the end of the IEC phantom to approximate the clinical situation of having activity that extends beyond the scanner field of view. The phantoms were filled with a solution of water and 18F (12 kBq/mL) and the spheres with various T/B ratios of 22.5, 10.3, and 3.6. Sequential imaging was performed to acquire PET images with varying background activity concentrations of about 12, 9, 6.4, 5.3, and 3.1 kBq/mL. The ESD was set to 60, 120, 180, and 240 s/bed. Data were fitted using two distinct multiple linear regression models for sphere ID < or = 10 mm and sphere ID > 10 mm. The fittings of both models were good with an R2 of 0.86 in both cases. Neither ESD nor Aacq resulted as significant predictors of the TH(%). For sphere ID < or =10 mm the target size was the most significant predictor of the TH(%), followed by the T/B ratio, while for sphere ID > 10 mm the explanatory power of the target size and T/B ratio were reversed, the T/B ratio being now the most important predictor of the TH(%). Both the target size and T/B ratio play a major role in explaining the variance of the TH(%), throughout the whole range of target sizes and T/B ratios examined. Thus, algorithms aimed at automatic threshold segmentation should incorporate both variables with a relative weight which critically depends on target size.

High dose dipyridamole myocardial imaging: simultaneous sestamibi scintigraphy and two-dimensional echocardiography in the detection and evaluation of coronary artery disease. Italian Group of Nuclear Cardiology

BACKGROUND

Dipyridamole stress combined with echocardiography or perfusion scintigraphy can be used to detect coronary artery disease, but head-to-head comparative data are lacking. The aim of this study was to compare the relative accuracy of high-dose dipyridamole stress imaging (up to 0.84 mg/kg over 10 min) with two-dimensional echocardiography and sestamibi perfusion scintigraphy in detecting coronary artery disease.

METHODS

One-hundred and one patients with a history of chest pain and no previous myocardial infarction, were studied simultaneously using planar perfusion scintigraphy and echocardiography during a high-dose dipyridamole stress, at seven different institutions.

RESULTS

During coronary angiography, 21 patients had non-significant lesions, and 80 had significant lesions (> or = 50% diameter reduction): 37 had single-, 19 double- and 24 triple-vessel disease. Sensitivity for disease detection was 78% [95% confidence interval (CI) 67-86%] for echocardiography and 79% (CI 68-87%) for scintigraphy. The specificity was 76% (CI 67-84%) for echocardiography and 90% (CI 83-95%) for scintigraphy. The inter-center variation in accuracy ranged from 50 to 100% for echocardiography (coefficient of variation 19.7%) and from 71 to 100% for scintigraphy (coefficient of variation 15%). The angiographically assessed extent and severity of coronary artery disease, evaluated using the Duke score, was correlated to the extent and severity of perfusion defects with scintigraphy (r = 0.65, P < 0.0001) and regional wall motion abnormalities by echocardiography (r = 0.57, P < 0.0001).

CONCLUSIONS

Perfusion scintigraphy and echocardiography have similar accuracies for the non-invasive identification of angiographically assessed coronary artery disease during high-dose dipyridamole stress. Inter-center variability in diagnostic accuracy is higher for echocardiography than scintigraphy. Both methods allow a reasonably accurate estimation of extent and severity of disease, via a semiquantitative assessment of extent and severity of perfusion of functional defects.

[Intracardiac ectopic thyroid: a report of a clinical case with a long-term follow-up]

We describe the prolonged follow-up of a 64-year-old female patient, with an ectopic intracardiac thyroid gland. The mass was first detected 14 years ago, during a routine echocardiographic examination. The patient suffered from episodes of palpitation and cardiac auscultation revealed a systolic murmur. At cardiac surgery a right ventricular mass penetrating most of the interventricular septum was found. The mass was also prolapsing into the pulmonary infundibulum and could not be removed. On histopathology examination, the presence of a normal tissue was demonstrated. Two main clinical events characterized the prolonged follow-up: the gradual development of a massive tricuspid insufficiency, probably due to the strict anatomic relationship between the septal tricuspid papillary muscle and the mass itself; frequent supraventricular arrhythmias, partially refractory to different pharmacologic regimens, which could be ascribed to the chronic overload of the right atrium. The mass size has been stable over the years, and no thyroid hormone derangement was ever found.

[Dual-chamber DDD pacing in NYHA III-IV functional class dilated cardiomyopathy: short and middle-term evaluation]

Effectiveness of dual-chamber pacing in patients with dilated cardiomyopathy is still controversial. Our study was performed: to select the most favorable individual atrioventricular (AV) delay; to compare hemodynamic short-term effects in each patient after 2 periods of DDD pacing and sinus rhythm (AV spontaneous); to assess hemodynamic long-term (1 year) effects after DDD pacing at optimum AV delay. In 1996, 9 patients (7 men, 2 women; mean age 69 +/- 5 years) with dilated cardiomyopathy (5 idiopathic, 4 ischemic), NYHA functional class III-IV, ejection fraction < 30%, end-diastolic volume > 60 ml/m2, mitral regurgitation +2/+3, PR interval > or = 200 ms, were enrolled. All patients were implanted with DDD pacemakers and monitored for: ejection fraction and end-diastolic volume (measured by echocardiography and radionuclide angiography); clinical conditions; exercise tolerance and maximum oxygen consumption (by Weber exercise protocol); neurohormonal activity (plasma renin, aldosterone, atrial natriuretic factor). Data were recorded: before DDD implantation; after 2 randomized, single-blind periods of 3 months in VVI mode (at ventricular "sentinel" rate of 50 b/min) and in DDD mode with the optimum AV delay, corresponding for each patient to the minimum end-diastolic volume measured by radionuclide angiography and to the highest cardiac output recorded by echocardiography; after 6 months of DDD pacing with most favorable AV delay. Three more patients died 6 months after (between sixth and twelfth month of follow-up), due to refractory heart failure; 1 patient dropped out because his pacemaker was programmed in VVI mode at low rate, due to intolerance of DDD pacing. Among the other 4 patients no clinical and laboratory parameters were significantly different after 1 year of follow-up. In conclusion, DDD pacing in selected patients with dilated cardiomyopathy showed disappointing results, despite a strict and laboratory monitoring; DDD pacing could be of major benefit in larger populations, according to Doppler mitral flow pattern: those patients with a larger A-wave amplitude could be more sensitive to DDD pacing than those with evidence of poor atrial systole. Moreover, biatral and/or biventricular pacing could also play a significant role.

Detection of moderate and severe coronary artery stenosis with technetium-99m tetrofosmin myocardial single-photon emission tomography

The aim of this study was to determine the diagnostic accuracy of technetium-99m tetrofosmin myocardial imaging for the localization of coronary artery stenoses of different degrees of severity. Stress-rest single-photon emission tomography (SPET) was performed on separate days in 80 patients (64 males, 16 females; mean age 61 years; 43 patients with previous myocardial infarction; 18 patients with pharmacological stress), within 6 months of coronary angiography. Scintigraphic images were blindly and independently evaluated by three observers. Coronary stenosis was defined as a >50% narrowing in luminal diameter; severe stenosis was defined as a proximal stenosis of >75% or a peripheral stenosis of >90%. Coronary angiography revealed normal coronary arteries or insignificant coronary stenosis in 13 patients and significant coronary stenoses in 67 patients. The sensitivity and specificity of 99mTc-tetrofosmin SPET in respect of severely stenosed vessels were, respectively, 80% and 65% for the left anterior descending artery (LAD), 100% and 46% for the right coronary artery (RCA) and 58 and 78% for the left circumflex artery (LCx) territories. Considering all the significantly stenosed vessels, a significant decrease in sensitivity was observed for LAD territories (to 59%, P=0.05), and a nonsignificant decrease for RCA (88%) and LCx (47%) territories while specificity values remained essentially unchanged. No significant changes in sensitivity or specificity were observed when regions with previous myocardial infarction were excluded. In conclusion, the sensitivity of 99mTc-tetrofosmin SPET for the localization of individual stenosed vessels is only moderate when all significant stenoses are considered, but the ability of this technique to predict the location of severe coronary artery stenoses seems satisfactory, with the exception of the low specificity in respect of RCA territories.

Feasibility of a rapid method to evaluate platelet survival time

The purpose of this study was to evaluate the feasibility of a shorter method of performing platelet kinetic studies with respect to the conventional 8-9-day approach.

METHODS

We studied 41 patients (28 women, 13 men; mean age 52 yr) with primary idiopathic thombocytopenic purpura (ITP) (n = 20), secondary ITP (n = 9), HCV associated thrombocytopenia (n = 9), splenectomy (n = 1) and hairy-cell leukemia (n = 1). The patients were in a steady-state of platelet turnover. Initial platelet counts ranged from 19 to 302 x 10(9)/liter (mean value = 83). Platelet survival times (PST) were measured from the blood radioactivity disappearance curve of 111In-oxine-labeled autologus platelets following the recommendations of the International Committee for Standardization in Haematology: blood samples were taken at 30 min and 2 and 4 hr and thereafter daily for 7 days. PST was calculated by the weighted mean method and ranged from 18 to 219 hr (mean value = 98). PST was also calculated using only the data collected at 2, 48 and 96 hr. If the radioactivity in the blood at 96 hr exceeded 10% of the 2-hr value, the additional point at 168 hr was used.

RESULTS

By using this reduced dataset, we obtained a correlation of r = 0.97 with the PST obtained from the whole dataset. In 24 patients, the difference was between +/- 10 hr and exceeded 1 day in only 4.

CONCLUSION

About 94% of the data may be recovered with only three or four blood samples and the duration may be shortened to 4 days in a significant proportion of patients (48% of ITP patients). This approach offers the advantages of increased patient throughput, compliance and reduced examination costs.

Quantitative scintigraphic evaluation of total knee arthroplasties: a feasibility study

For the development and validation of a quantitative approach to the analysis of bone scans after total knee arthroplasty, 39 consecutive patients with 40 prostheses (6 males, 33 females; mean age, 70 years) were scheduled for clinical, radiographic, and scintigraphic examination ranging from 9 to 90 months after surgery. Twenty-seven total knee arthroplasties were considered to be asymptomatic and 13 symptomatic according to the clinical and radiographic findings. Significant differences were found for 99mTc-methylene diphosphonate uptake for femur and tibia and between symptomatic and asymptomatic patients. A reference range was determined for radionuclide uptake in the periprosthetic bone of the 27 asymptomatic total knee arthroplasties; this range was then used to identify loose total knee arthroplasties among the 13 symptomatic knees. With a clinical and radiographic followup performed 1 year after scintigraphy as a standard of comparison, a sensitivity of 88% (7/8) and a specificity of 100% (5/5) was demonstrated. These preliminary results suggest the feasibility of a quantitative approach to the scintigraphic evaluation of total knee arthroplasties after the first postsurgical year.

A laboratory and thrombokinetic study of HCV-associated thrombocytopenia: a direct role of HCV in bone marrow exhaustion?

OBJECTIVE

In order to investigate HCV associated thrombocytopenia, 6 patients suffering from this disease, in the absence of splenomegaly and other common causes of peripheral platelet destruction, underwent laboratory and scintigraphic tests.

RESULTS

Thrombokinetic studies revealed a significant, nearly linear, delayed splenic accumulation with normal or low-normal values for the average platelet life span, low-normal recovery, and depressed platelet production. Megakariopoiesis was normal or slightly increased. HCV infection of the megakariocytes was found in two patients. Autoantibodies and liver disease were also investigated.

CONCLUSIONS

A role of immunological mechanisms in HCV associated thrombocytopenia appears to be ruled out. The authors conclude that tests for HCV infection should be included in the evaluation of thrombocytopenia in adults and a possible direct involvement of HCV cannot be excluded.

Lung uptake of 201Tl in myocardial stress imaging: correlation with echocardiographic and scintigraphic variables of myocardial ischaemia

The lung uptake of thallium-201 (201Tl) in planar imaging was evaluated in 384 patients enrolled in the SIRT study (Italian Multicentre Study on Thallium Reinjection). All patients underwent treadmill exercise, and at peak exercise 74 MBq of 201TI were injected. The patients were then evaluated after reinjection of 201Tl under baseline conditions. The left ventricle was subdivided into 16 echocardiographic and 15 scintigraphic segments. The best correlates of visually scored 201Tl lung uptake, of the lung heart ratio and lung wash-out were checked. The independent variables entered in the stepwise multiple-regression analysis were: the echocardiographic wall motion index, the scintigraphic perfusion score index, and the number of segments that improved by at least 1 and 2 grades after redistribution and after reinjection. We concluded that the lung:heart ratio and, in particular, lung wash-out do not correlate more closely than the visual score with the variables taken into consideration. This suggests that visually scored lung uptake of 201Tl is still of value in nuclear cardiology practice. The scintigraphic variables associated with reinjection do not seem to offer any additional information with respect to redistribution variables. We also analysed the impact on 201Tl lung uptake of several other index variables. Student's t-test revealed that no single variable significantly alters lung uptake after stress testing.

Assessment of myocardial viability after thallium-201 reinjection or rest-redistribution imaging: a multicenter study. The Italian Group of Nuclear Cardiology

To establish the real nature of 201Tl defects in the assessment of myocardial viability (e.g., fixed versus reversible), 201Tl reinjection was evaluated in a multicenter trial involving 402 consecutive patients with ischemic heart disease and exercise 201Tl defects.

METHODS

Twelve hospitals, using the same type of gamma camera and computer software, adopted one of the two most widely used reinjection protocols. In 230 patients (Group A), reinjection was performed immediately after stress-redistribution planar imaging; in 172 patients (Group B), reinjection was performed on a separate day and followed by rest-redistribution imaging. The images were interpreted by three blinded observers in a core laboratory on a five-point qualitative scale; the reproducibility in visual scoring was excellent.

RESULTS

Groups A and B had a similar prevalence of myocardial segments with abnormal uptake at stress (39%, 40%), as well as with reversible (16%, 17%), partially reversible (21%, 19%) and irreversible (63%, 64%) defects at redistribution. After reinjection, 201Tl uptake improved in 27% and 36% of both partially reversible and irreversible defects in Groups A and B. No differences were found when comparing early and delayed reinjection imaging in Group B.

CONCLUSION

This study confirms the validity of 201Tl reinjection in a large, unselected population, but the discordance with stress/redistribution is less than has been previously reported for both 201Tl reinjection protocols, the prevalence of improved segments after reinjection was higher with the separate day approach.

The clinical value of prostate-specific antigen and bone scintigraphy in the staging of patients with newly diagnosed, pathologically proven prostate cancer

Recent reports suggest that radionuclide bone scan (BS) may not be necessary in the standard staging evaluation of patients with prostate cancer when serum prostate-specific antigen (PSA) levels are normal. To evaluate the ability of PSA to predict BS findings, we retrospectively reviewed the case records of 118 consecutive patients (median age 73 years, range 50-90 years) with newly diagnosed, untreated, pathologically proven prostate cancer who underwent BS and serum PSA sampling within a period of no more than 3 months. Fifty-four out of 118 BSs demonstrated metastatic bone disease. A PSA value of less than 10 ng/ml excluded bone metastasis; of 35 patients with a serum PSA level of 20 ng/ml or less, seven had a positive BS (negative predictive value of 80%). These findings provide additional confirmation of the value of low serum PSA concentrations in excluding the need for a staging BS, although the threshold for a high value of negative predictive accuracy is lower than previously reported.

Assessment of interferon cardiotoxicity with quantitative radionuclide angiocardiography

Three different types of cardiovascular sequelae attributed to interferon therapy have been reported: arrhythmia, ischaemic heart disease and cardiomyopathy. We evaluated the left ventricular ejection fraction (LVEF) during alpha interferon therapy (3 MU administered subcutaneously three times a week for 6 months) in 11 patients with chronic viral hepatitis. LVEF was within the normal range in all patients (mean value +/- SD 64.6 +/- 10.7%) before interferon was started, but decreased after 1 month of therapy (mean value +/- SD 59.7 +/- 8.3%) (P = 0.015). An LVEF reduction of more than 10% was observed in five of the 11 patients. Three months after therapy was stopped, nine of the 11 patients showed an LVEF close to the pre-treatment level (mean value +/- SD 62.1 +/- 8.3%). In our patients with chronic C hepatitis, low subcutaneous doses of interferon alpha often decreased the LVEF. It is not clear whether this finding is due to the direct effect of interferon on cardiac cells, or to the peripheral vascular effects of the drug. As LVEF reduction could be critical in patients with previously reduced myocardial contractility, our results further highlight the need for careful cardiac analysis before starting interferon therapy.

Maldistribution of regional myocardial perfusion at rest in patients with coronary artery disease and no previous myocardial infarction, evidenced by 99mTc-Sestamibi scintigraphy

Since myocardial 99mTc-Sestamibi uptake is closely related to coronary blood flow and the tracer does not redistribute, resting perfusion defects may be observed even in viable regions supplied by vessels with severe stenosis. The incidence and the clinical significance of 99mTc-Sestamibi uptake defects at rest were investigated in 60 men with suspected coronary artery disease and no previous myocardial infarction, in a multicenter study. Of 60 patients, 12 showed normal coronary arteries and 48 significant coronary artery disease (> 50% luminal narrowing). Based on the presence or absence of tracer uptake defects at resting planar scans, the patients were divided into Group 1 (27 patients) and Group 2 (33 patients), respectively. A greater incidence of coronary artery disease (100% versus 64%, p < 0.01) and of multivessel disease (70% versus 36%, p < 0.05) was observed in patients of Group 1. All patients underwent dipyridamole (up to 0.84 mg/kg in 10 min) 99mTc-Sestamibi scintigraphy, which more frequently induced transient 99mTc-Sestamibi uptake defects in Group 1 than in Group 2 (85% versus 42%, p < 0.001). A high incidence of resting 99mTc-Sestamibi uptake defects was observed in patients without previous myocardial infarction; this identified a subset of patients with a higher prevalence of coronary artery disease and multivessel involvement and with a greater impairment of the coronary reserve, as evidenced by a dipyridamole test.

A multicenter trial on interobserver and intraobserver reproducibility of segmental scoring of thallium-201 planar myocardial imaging before and after reinjection. Italian Group of Nuclear Cardiology

Inter- and intraobserver reproducibility (R) of segmental 201Tl scores after stress (ST), redistribution (RD) and reinjection (RI) planar imaging were evaluated.

METHODS

Images were examined from 396 patients with suspected coronary artery disease, demonstrated by means of post-ST imaging of at least one perfusion defect. To eliminate external sources of variability, the same gamma camera, acquisition protocol and computer software were used in this multicenter study. Thallium-201 images of the anterior, left anterior oblique and left lateral projections were obtained immediately, 4 hr after exercise and 30 min after the injection of additional 201Tl either on the same day or on a different day. The left ventricle was divided into 15 segments and evaluated by three independent observers, blinded to clinical data, according to a five-point scale.

RESULTS

The R score for ST, RD and RI images, expressed as an intraclass correlation coefficient, was 0.76, 0.74 and 0.72, respectively. After averaging multiple observer scores, R increased to 0.91, 0.90 and 0.89, respectively. Individual observer measurement of the R score was 0.48, 0.51 and 0.32 for ST-RD, ST-RI and RD-RI image pairs, respectively, and multiple observer scores showed R increases to 0.74, 0.76 and 0.58.

CONCLUSION

This qualitative scale reliably assesses the severity of 201Tl perfusion defects, particularly when multiple-observer scores are averaged. Individual observer change scores should be taken with great caution, especially in studies involving the visual evaluation of RD-RI image changes.

Residual coronary reserve despite decreased resting blood flow in patients with critical coronary lesions. A study by technetium-99m human albumin microsphere myocardial scintigraphy

BACKGROUND

Experimental data demonstrate the persistence of a transmural vasodilator reserve in the face of depressed resting myocardial perfusion. The present study was designed to determine whether resting myocardial hypoperfusion indicates exhausted coronary reserve (CR).

METHODS AND RESULTS

Fifteen patients with stable angina, isolated left anterior descending coronary artery (LAD) stenosis, and no previous myocardial infarction were evaluated by means of 99mTc human albumin microsphere scintigraphy. Regional myocardial perfusion and CR were assessed at baseline and after LAD papaverine (10-12 mg) by means of two microsphere injections in the left ventricle and compared with five normal subjects. Two 300-second scans were obtained with a mobile gamma camera positioned in the 70 degrees left anterior oblique projection; actual microsphere distribution after papaverine was obtained by image subtraction. The two arterial input functions (basal and papaverine) were measured from the first-pass time-activity curves and validated with the reference arterial sample technique. From the comparison of circumferential profile analysis between patients and normal subjects, nine patients (group 1A) showed perfusion defects at rest (reduction of percent radioactivity below 2 SD of normal subjects) in the LAD territory, and the other six (group 1B) showed homogeneous perfusion. CR (papaverine/resting perfusion) was 3.8 +/- 0.2 and 1.51 +/- 0.27 in normal subjects and in ischemic patients, respectively (p < 0.01). Despite resting hypoperfusion, group 1A showed a papaverine-recruitable CR similar to that of group 1B (1.57 +/- 0.33 and 1.43 +/- 0.16, respectively, p = NS).

CONCLUSIONS

In patients with stable angina pectoris, isolated LAD stenosis, and no previous myocardial infarction, microsphere scintigraphy disclosed a high incidence of resting perfusion defects; in those patients, a residual CR was observed despite decreased resting blood flow.

Thallium-201: what do we gain from new clinical protocols and acquisition procedures? The Italian Study on Thallium Reinjection/SIRT)

Nine medical centers, equipped with the same gamma camera and computer software, participated in this multicenter study on thallium-201 reinjection imaging. Preliminary findings for the first 143 patients with ischemic heart disease and perfusion defects at stress imaging are reported. Eighty-eight patients were reinjected at rest after conventional stress-redistribution imaging. Another 55 patients were reinjected at rest on a separate day. After segmental comparison of conventional redistribution versus stress imaging, differences > 1 in the segmental scores on a reduced 3 point scale identified 58 patients with irreversible or mainly irreversible defects (dominant scar pattern) and 85 patients with reversible or mainly reversible defects (dominant ischemic pattern). When reinjection was compared to stress images, 24 patients out of 58 with a dominant scar pattern at the conventional analysis were then assigned to the group with a dominant ischemic pattern. No clinical variables or exercise stress data were found to be significantly different in this patient subgroup. Only 4 out of 85 patients with a dominant ischemic pattern were reassigned to a dominant scar pattern after reinjection scoring. These preliminary results of the SIRT study confirm the consistent problem of scar overestimation by conventional stress-redistribution imaging and the clinical value of the thallium-201 reinjection procedure for differentiating viable from necrotic myocardium.

Accuracy and safety of technetium-99m hexakis 2-methoxy-2-isobutyl isonitrile (Sestamibi) myocardial scintigraphy with high dose dipyridamole test in patients with effort angina pectoris: a multicenter study. Italian Group of Nuclear Cardiology

Clinical and physiologic evidence indicates that maximal coronary vasodilation is not achieved in a large number of patients with use of the standard dose of dipyridamole (0.56 mg/kg body weight over 4 min). The feasibility, safety and accuracy of technetium-99m hexakis 2-methoxy-2-isobutyl isonitrile (Sestamibi) scintigraphy associated with intravenous high dose dipyridamole (0.56 mg/kg over 4 min followed 4 min later by an additional 0.28 mg/kg over 2 min) were evaluated in a multicenter study. Planar myocardial perfusion images were obtained at rest and after dipyridamole in 101 patients with effort chest pain and no prior myocardial infarction. High dose dipyridamole (62 patients) was used when typical chest pain or electrocardiographic (ECG) signs of ischemia, or both, did not occur during or after the standard dose (39 patients). With high dose dipyridamole, 34 patients had pain (18 patients) or ECG signs of ischemia (ST depression greater than or equal to 2 mm) (8 patients), or both (8 patients), whereas the other 28 patients had Sestamibi injection in the absence of symptoms or ECG changes. All patients underwent coronary angiography: 81 had significant coronary artery disease (greater than or equal to 50% reduction of lumen diameter) (affecting one vessel in 38, two vessels in 19 and three vessels in 24 patients) and 20 patients had normal coronary arteries. The overall sensitivity, specificity and predictive accuracy of Sestamibi scintigraphy were 81%, 90% and 83%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

European multi-centre comparison of thallium 201 and technetium 99m methoxyisobutylisonitrile in ischaemic heart disease

Fifty-six patients in Europe were entered into a multi-centre study to compare the accuracy of technetium 99m methoxyisobutylisonitrile (99mTc-MIBI) for the detection of coronary artery disease (CAD) with thallium 201 (201Tl) chloride perfusion scanning. The results showed a high degree of concordance between the two radiopharmaceuticals. Some 81% (678/840) of myocardial segments showed the same result (normal, infarct or ischaemia), and 80% (45/56) of patients had the same diagnosis. Overall detection of CAD in patients was 98% for 201T1 and 96% for 99mTc-MIBI. Detection of CAD in total arteries was 68% for both agents. In this study 99mTc-MIBI was as accurate as 201Tl for the detection of coronary artery stenoses.