RADIOIODINATION AND PHARMACOKINETICS OF BIVALENT ANALOG OF PRACTOLOL AS MYOCARDIAL IMAGING AGENT

Solid phase exchange radioiodination method was used to label the compound.Pharmacokinetics was studied in rats and the data were dealt with by computer. The results indicate that the compound would be a potential myocardial imaging agent.

Assessment of Effect of Shexiang Baoxin Pill for Labour Angina Pectoris Patients with Computerized Tomography Myocardial Imaging

Objective:To assess the effect of Shexiang Baoxin Pill（SXBXP）for labour angina pectoris.Methods:Effect of 66 patientstreated withconven tional treatment or conventional treatment plus SXBXP were observed and compared with^(99m) TC-MIBI singlepho tonemissi on computerized tomography（SPECT）target cardiograph to estimate is chemia my ocardial area.Results:The total effectiverate was much higher in patients treated with SXBXP than that in patients treated with conventional treatment only（87.8%vs.56%,P＜0.05）.The effective rate on ECG in the two group swas 70.7% and 52%respectively,with out significant statistical difference between them（P＞0.05）.While significant difference was observed in is chemiaarea of my ocardiali mage between the two groups after treatment,18.2±8.2%vs23.8±9.8%,P<0.05.Moreover,there currence of anginapect or is and cardiaceven twerealsolessin the SXBXPgroup.Conclusion:the SXBXP was effective for labourangina pectoris.

Quantitative Analysis of the Tomographic Technetium-99m MIBI (^(99m)Tc-MIBI) Myocardial Bullseye Display: Application to Diagnosis of Coronary Artery Disease

In this study, the 99mTc-MIBI myocardial bullseye display of 31 healthy persons and 34 patients with myocardial ischemia and 17 patients with myocardial infarction were analyzed quantitatively, and compared with the results of myocardial tomography analysis and qualitative bullseye analysis. The sensitivities of the three methods were 88.2%, 91.2 % and 94.1 % respectively (P>0.05),and the specificities were 93. 5%, 83, 9% and 83. 9% respectively (P<0.05).On the other hand, the quantitative analysis obviously outperformed the other two methods in the detection of ischemic segments of myocardium near infarction zone (P<0. 01). The quantitative analysis of 99mTc-MIBI myocardial bullseye (quantitative bullseye) was an objective, specific and sensitive method for diagnosis of coronary artery disease.

Predicting major adverse cardiovascular events after orthotopic liver transplantation using a supervised machine learning model:A cohort study

BACKGROUND Liver transplant(LT)patients have become older and sicker.The rate of post-LT major adverse cardiovascular events(MACE)has increased,and this in turn raises 30-d post-LT mortality.Noninvasive cardiac stress testing loses accuracy when applied to pre-LT cirrhotic patients.AIM To assess the feasibility and accuracy of a machine learning model used to predict post-LT MACE in a regional cohort.METHODS This retrospective cohort study involved 575 LT patients from a Southern Brazilian academic center.We developed a predictive model for post-LT MACE(defined as a composite outcome of stroke,new-onset heart failure,severe arrhythmia,and myocardial infarction)using the extreme gradient boosting(XGBoost)machine learning model.We addressed missing data(below 20%)for relevant variables using the k-nearest neighbor imputation method,calculating the mean from the ten nearest neighbors for each case.The modeling dataset included 83 features,encompassing patient and laboratory data,cirrhosis complications,and pre-LT cardiac assessments.Model performance was assessed using the area under the receiver operating characteristic curve(AUROC).We also employed Shapley additive explanations(SHAP)to interpret feature impacts.The dataset was split into training(75%)and testing(25%)sets.Calibration was evaluated using the Brier score.We followed Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis guidelines for reporting.Scikit-learn and SHAP in Python 3 were used for all analyses.The supplementary material includes code for model development and a user-friendly online MACE prediction calculator.RESULTS Of the 537 included patients,23(4.46%)developed in-hospital MACE,with a mean age at transplantation of 52.9 years.The majority,66.1%,were male.The XGBoost model achieved an impressive AUROC of 0.89 during the training stage.This model exhibited accuracy,precision,recall,and F1-score values of 0.84,0.85,0.80,and 0.79,respectively.Calibration,as assessed by the Brier score,indicated excellent model calibration with a score of 0.07.Furthermore,SHAP values highlighted the significance of certain variables in predicting postoperative MACE,with negative noninvasive cardiac stress testing,use of nonselective beta-blockers,direct bilirubin levels,blood type O,and dynamic alterations on myocardial perfusion scintigraphy being the most influential factors at the cohort-wide level.These results highlight the predictive capability of our XGBoost model in assessing the risk of post-LT MACE,making it a valuable tool for clinical practice.CONCLUSION Our study successfully assessed the feasibility and accuracy of the XGBoost machine learning model in predicting post-LT MACE,using both cardiovascular and hepatic variables.The model demonstrated impressive performance,aligning with literature findings,and exhibited excellent calibration.Notably,our cautious approach to prevent overfitting and data leakage suggests the stability of results when applied to prospective data,reinforcing the model’s value as a reliable tool for predicting post-LT MACE in clinical practice.

Use of gated myocardial perfusion imaging to assess clinical value of Xinmailong injection in chronic congestive heart failure

OBJECTIVE: This study used gated myocardial perfusion imaging(G-MPI) to assess the clinical value of Xinmailong injection in chronic congestive heart failure(CHF).METHODS: A total of 102 CHF patients were randomly divided into the control group(n=51) and the Xinmailong group(n=51). Patients in the control group were routinely treated. Patients in the Xinmailong group were additionally treated with Xinmailong injection in addition to routine treatment. Before and 3 months after treatment, G-MPI was used to determine changes in the left ventricular ejection fraction(LVEF), left ventricular end-diastolic volume(LVEDV) and left ventricular end-systolic volume(LVESV). Fourteen days after treatment, changes in plasma brain natriuretic peptide(BNP) levels were determined.RESULTS: Before treatment, there were no significant differences in LVEF, LVEDV, LVESV, and BNP levels between the two groups(all P>0.05). After treatment, LVEDV, LVESV, and BNP levels were significantly lower, and LVEF was significantly higher in the Xinmailong group than in the control group(all P<0.05).CONCLUSION: Additional use of Xinmailong injection in addition to routine treatment improves cardiac function of CHF patients. Because of the safety and effectiveness of Xinmailong injection, this therapy should be promoted.

Cardiac stress testing and coronary artery disease in liver transplantation candidates： Meta-analysis

dAIMTo evaluate the diagnostic value of dobutamine stress echocardiography （DSE） and myocardial perfusion sci-ntigraphy （MPS） in predicting coronary artery disease （CAD） in cirrhotic patients listed for liver transplanta-tion （LT）, using invasive coronary angiography （ICA） as gold-standard.METHODSRetrieval of studies was based on Medical Subject Headings and Health Sciences Descriptors, which were combined using Boolean operators. Searches were run on the electronic databases Scopus, Web of Science, EMBASE, MEDLINE （PubMed）, BIREME （Biblioteca Regional de Medicina）, LILACS （Latin American and Cari-bbean Health Sciences Literature）, Cochrane Library for Systematic Reviews and Opengray.eu. There was reference lists of the studies retrieved were searched manually.RESULTSThe search strategy retrieved 322 references for DSE and 90 for MPS. In the fnal analysis, 10 references for DSE and 10 for MPS were included. Pooled sensitivity was 28% and 61% for DSE and MPS and specificity was 82% and 74%, for diagnosis of CAD using ICA as gold-standard, respectively.CONCLUSIONDSE and MPS do not have adequate sensitivity for determination of whether CAD is present, despite having signifcant specifcity.

Significance of inferior wall ischemia in non-dominant right coronary artery anatomy

AIM To investigate the relationship of inferior wall ischemia on myocardial perfusion imaging in patients with nondominant right coronary artery anatomy.METHODS This was a retrospective observational analysis of consecutive patients who presented to the emergency department with primary complaint of chest pain.Only patients who underwent single photon emission computed tomography(SPECT)myocardial perfusion imaging(MPI)were included.Patients who showed a reversible defect on SPECT MPI and had coronary angiography during the same hospitalization was analyzed.Patients with prior history of coronary artery disease(CAD)including history of percutaneous coronary intervention and coronary artery bypass graft surgerys were excluded.True positive and false positive results were identified on the basis of hemodynamically significant CAD on coronary angiography,in the same territory as identified on SPECT MPI.Coronary artery dominance was determined on coronary angiography.Patients were divided into group 1 and group 2.Group1 included patients with non-dominant right coronary artery(RCA)(left dominant and codominant).Group2 included patients with dominant RCA anatomy.Demographics,baseline characteristics and positive predictive value(PPV)were analyzed for the two groups.RESULTS The mean age of the study cohort was 57.6 years.Sixtyone point seven percent of the patients were males.The prevalence of self-reported diabetes mellitus,hypertension and dyslipidemia was 36%,71.9%and 53.9%respectively.A comparison of baseline characteristics between the two groups showed that patients with a non-dominant RCA were more likely to be men.For inferior wall ischemia on SPECT MPI,patients in study group 2 had a significantly higher PPV,32/42(76.1%),compared to patients in group 1,in which only 3 out of the 29 patients(10.3%)had true positive results(P value<0.001 Z test).The difference remained statistically significant even when only patients with left dominant coronary system(without co-dominant)were compared to patients with right dominant system(32/40,76.1%in right dominant group,3/19,15.8%in left dominant group,P value<0.001 Z test).There was no significant difference in mean hospital stay,re-hospitalization,and in-hospital mortality between the two groups.CONCLUSION The positive predictive value of SPECT MPI for inferior wall ischemia is affected by coronary artery dominance.More studies are needed to explain this phenomenon.

Hige namine as a Potential Pharmacologic Stress Age nt in the Detection of Coro nary Artery Disease

Myocardial perfusion imaging(MPI) is valuable for the diagnosis,prognosis,and management of coronary artery disease(CAD).The most commonly used pharmacologic stress agents at present are vasodilators and adrenergic agents.However,these agents have contraindications and may cause adverse effects in some patients.Thus,other stress agents feasible for more patients are required.Higenamine(HG) is a β-adrenergic receptor agonist currently approved for clinical trials as a stress agent for myocardial infarction.It also has a promising value in MPI for the detection of CAD in preclinical and clinical studies.This review summarizes the application of HG on MPI,including its mechanism of action,stress protocol,efficacy,and safety.

Role of speckle tracking imaging in the assessment of myocardial regional ventricular function in experimental blunt cardiac injury

Purpose： To evaluate the usefulness and information collecting ability of speckle tracking imaging techniques in the assessment of myocardial regional ventricular contractility in a rabbit model with blunt cardiac injury. Methods： Fifteen healthy New Zealand rabbits weighing （2.70 ± 0.28） kg were anesthetized （3% pentobarbital sodium/i.v） and impacted using the BIM-II biological impact machine to induce myocardial contusion （MC）. Hemodynamic parameters, such as heart rate, systolic pressure, mean arterial pressure, diastolic pressure and central venous pressure, were determined before and after MC. Further, param- eters reflecting left ventricular functions, such as left ventricular end systolic pressure, left ventricular end diastolic pressure, isovolumic pressure （IP） and the maximal increasing/decreasing rate of left intraventricular pressure （±dp/dtmax）, were also determined before and after MC. Left ventricular functions were determined either by two dimensional transthoracic echocardiography or by speckle tracking imaging for segmental abnormal ventricular wall motions. Results： Heart rate, systolic pressure, diastolic pressure and mean arterial pressure decreased signifi- cantly but transiently, while central venous pressure markedly increased after MC. In contrast to significant changes in diastolic functions, there was no significant change in cardiac systolic functions after MC. The speckle tracking imaging demonstrated that strain values of different myocardial segment significantly decreased post impact, and that of the ventricular segment decreased from segment to segment. Conclusion： Speckle tracking imaging is useful and informative to assess myocardial regional dysfunctions post MC.

Myocardial perfusion imaging with a contrast agent at a low concentration in the diagnosis of myocardial infarction in the elderly

Objective To evaluate the clinical value of myocardial perfusion imaging with dual-source dual-energy CT and a contrast agent at a low concentration in the diagnosis of myocardial infarction in the elderly.Methods Onestop cardiac imaging with dual-source CT was conducted in 138 elderly patients diagnosed with myocardial infarction between October 2015 and May 2016.The

Pilot study of gated-PET / CT for evaluating myocardial blood-supply and myocardial metabolism in pigs

Background As for the patients with coronary arteriosclerosis, the presence of ischemic myocardial survival is significant for the treatment and prognosis. Gated 13N-NH3 and 18SF-FDG PET/CT imaging provides myocardial perfusion, metabolism and cardiac function which can valuate myocardial viability accurately and noninvasively. Methods Four pigs were subjected to bilateral internal mammary artery Y-bypass operation in operating room. The pigs under the anesthetized state were sent to PET center when the operation finished. Then 13N-NH3 gated-PET/CT and 18F-FDG gated-PET/CT were performed. Results The myocardial perfusion and myocardial metabolism is well-distributed of left ventricular wall. The motion of the wall was normal. The ejection function was greater than 50%. Conclusion Gated-PET/CT can be used for noninvasive evaluation of myocardial perfusion, myocardial metabolism and left ventricle function.