Role of heart fatty acid binding protein in early detection of non ST-elevation myocardial infarct and its comparison with other cardiac markers.

OBJECTIVE: To determine the role of heart fatty acid-binding protein in early detection of non-ST-elevation myocardial infarction and its comparison with two other cardiac markers. METHODS: The cross-sectional study was conducted at Abbasi Shaheed Hospital, Karachi, from June 2012 to June 2014, and comprised patients presenting at the emergency department within two hours of chest pain and who were subsequently referred to the cardiology department with a provisional diagnosis of either unstable angina or non-ST-elevation myocardial infarction. Relevant history was taken on a specific proforma and electrocardiogram as well as routine investigations were done in the emergency department. Blood samples from the subjects were tested for the diagnosis of myocardial infarction through detection of heart fatty acid-binding protein, Troponin-I and Creatine kinase-myocardial band. Sensitivity and specificity of the three markers were calculated keeping coronary angiography as the gold standard. Data was analysed using SPSS 17. RESULTS: Out of 250 patients, 153(61.2%) were males. The overall mean age was 54.45±13.92 years. Sensitivity and specificity of heart fatty acid-binding protein were 80.6% and 78.5% (p<0.05), for Troponin-I, 37.7% and 75% (p>0.05), and for Creatine Kinase-myocardial band, 29.5% and 67.8% (p>0.05). CONCLUSIONS: Heart fatty acid-binding protein was found to be a good diagnostic tool for the detection of non-ST-elevation myocardial infarction.

Cardiovascular adverse events associated with immune checkpoint inhibitors: A retrospective multicenter cohort study.

BACKGROUND: Over the past decade, immune checkpoint inhibitors (ICIs) have significantly transformed cancer treatment. However, ICIs inevitably may cause a spectrum of immune-related adverse events, among which cardiovascular toxicity, particularly myocarditis, while infrequent, has garnered increasing attention due to its high fatality rate. METHODS: We conducted a multicenter retrospective study to characterize ICI-associated cardiovascular adverse events. Logistic regression was performed to explore the risk factors for the development of myocarditis and severe myocarditis. Receiver operating characteristic curves were conducted to assess the diagnostic abilities of cardiac biomarkers to distinguish different cardiovascular toxicities, and the performance and calibration were evaluated using Hosmer-Lemeshow test. RESULTS: Forty-four patients were identified, including thirty-five myocarditis, five heart failure, three arrhythmias, and one myocardial infarction. Compared with other patients, myocarditis patients had higher cardiac troponin-I (cTnI) levels (p < 0.001), higher creatine kinase levels (p = 0.003), higher creatine kinase isoenzyme-MB (CK-MB) levels (p = 0.013), and shorter time to the incidence of adverse cardiovascular events (p = 0.022) after ICI treatment. Twenty-one patients (60%) were classified as severe myocarditis, and they presented higher cardiac troponin I (cTnI) levels (p = 0.013), higher N-terminal pro-B-type natriuretic peptide levels (p = 0.031), higher creatine kinase levels (p = 0.018), higher CK-MB levels (p = 0.026), and higher neutrophil to lymphocyte ratio (NLR) levels (p = 0.016) compared to non-severe myocarditis patients after ICI treatment. Multivariate logistic regression showed that CK-MB (adjusted odds ratio [OR]: 1.775, 95% confidence interval [CI]: 1.055-2.984, p = 0.031) was the independent risk factor of the development of ICI-associated myocarditis, and cTnI (adjusted OR: 1.021, 95% CI: 1.002-1.039, p = 0.03) and NLR (adjusted OR: 1.890, 95% CI: 1.026-3.483, p = 0.041) were the independent risk factors of ICI-associated severe myocarditis. The receiver operating characteristic curve showed an area under curve of 0.785 (95% CI: 0.642 to 0.928, p = 0.013) for CK-MB, 0.765 (95% CI: 0.601 to 0.929, p = 0.013) for cTnI, and 0.773 for NLR (95% CI: 0.597 to 0.948, p = 0.016). CONCLUSIONS: Elevated CK-MB after ICI treatment is the independent risk factor for the incidence of ICI-associated myocarditis, and elevated cTnI and NLR after ICI treatment are the independent risk factors for the development of ICI-associated severe myocarditis. CK-MB, cTnI, and NLR demonstrated a promising predictive utility for the identification of ICI-associated myocarditis and severe myocarditis.

Elevated Myoglobin in Patients With Primary Aldosteronism: A Cross-Sectional Study.

Objectives: Primary aldosteronism (PA) is characterized by the autonomous excessive production of aldosterone in the adrenal cortex. Aldosterone is associated with damages to heart muscle and skeletal muscle. The purpose of this study was to evaluate serum levels of muscle injury markers and their associated factors in patients with primary aldosteronism. Methods: We retrospectively enrolled subjects with PA and essential hypertension (EH) who had completed testing for serum high sensitivity troponin T (hs-TnT), creatine kinase isoenzyme MB (CK-MB) and myoglobin from the database of the Chongqing Primary Aldosteronism Study (CONPASS). Univariate and multivariate linear regression analyses were performed to analyze the influencing factors of myocardial injury markers. Results: In total, 278 patients with PA and 445 patients with EH were enrolled in this study. Compared with EH patients, serum concentrations of hs-TnT [7.0 (4.0-12.0) vs. 6.0 (3.0-11.0) ng/L; p=0.005] and myoglobin [24.2 (21.0-38.1) vs. 21.8 (21.0-31.9) µg/L; p=0.023] were significantly higher among PA patients, while no significant difference of CK-MB was found between two groups [1.4 (1.0-2.0) vs. 1.3 (0.9-1.9) µg/L; p=0.154]. Univariate linear regression analysis showed that myoglobin was negatively correlated with serum potassium (ß=-0.31; p<0.01) and positively correlated with plasma aldosterone concentration (ß=0.40; p<0.01) in the PA group, while no significant correlation was found between hs-TnT and biochemical parameters. After adjusting for multiple confounders, myoglobin was negatively correlated with serum potassium (ß=-0.15; p<0.05) and positively correlated with plasma aldosterone concentration (ß=0.34; p<0.01) in the PA group. Conclusions: The serum level of myoglobin was significantly increased in PA patients, and myoglobin was independently correlated with plasma aldosterone concentration.

A novel scoring system to estimate chemotherapy-induced myocardial toxicity: Risk assessment prior to non-anthracycline chemotherapy regimens.

BACKGROUND: Myocardial toxicity is a common side effect of chemotherapy and is associated with adverse outcomes in cancer patients. Sufficient prediction of chemotherapy-induced myocardiotoxicity (CIMC) is desirable. Therefore, we sought to develop a feasible scoring system to predict CIMC in cancer patients undergoing non-anthracycline chemotherapy. METHODS: We determined a scoring system, the "Cardiotoxicitiy Score" (the CardTox-Score), by multivariable regression of the parameters considered relevant to the development of CIMC, based on previously published data and current guidelines. Variables of the risk model consist of clinical (age, presence of cardiovascular risk conditionsconditions), blood tests (NT-proBNP), and echocardiographic parameters (left ventricular (LV) ejection fraction, LV strain analysis). The CardTox-Score was examined in an internal validation cohort by use of ROC and regression analysis. RESULTS: We prospectively investigated 225 patients (58.21 ± 6.3 years, 52.8% female) who received non-anthracycline myocardiotoxic anticancer agent as a derivation cohort. All patients underwent echocardiography before, during and after anticancer therapy. The mean follow-up duration was 25 ± 4 months. We found the CardTox-Score (>6 points) to be a strong independent predictor (AUC: 0.983, OR: 6.38, 95% CI: 1.6 2.8, p < 0.001) for the development of CIMC with high sensitivity (100%) and specificity (84.2%) in the validation cohort (n = 30, 59.2 ± 6.5 years, 57% female). Moreover, the CardTox-Score appropriately predicted all-cause mortality with high specificity (93.7%) and sensitivity (92.9%) as well (OR: 4.85, AUC: 0.978, p = 0.01). CONCLUSION: The CardTox-Score offers a promising, feasible, and easy-to-handle scoring system for predicting CIMC in cancer patients undergoing non-anthracycline regimes, independent from the type of cancer.

Protocatechuic aldehyde protects cardiomycoytes against ischemic injury via regulation of nuclear pyruvate kinase M2.

Rescuing cells from stress damage emerges a potential therapeutic strategy to combat myocardial infarction. Protocatechuic aldehyde (PCA) is a major phenolic acid in Chinese herb Danshen (Salvia miltiorrhiza root). This study investigated whether PCA regulated nuclear pyruvate kinase isoform M2 (PKM2) function to protect cardiomyocytes. In rats subjected to isoprenaline, PCA attenuated heart injury and protected cardiomyocytes from apoptosis. Through DARTS and CETSA assays, we identified that PCA bound and promoted PKM2 nuclear translocation in cardiomyocytes exposed to oxygen/glucose deprivation (OGD). In the nucleus, PCA increased the binding of PKM2 to ß-catenin via preserving PKM2 acetylation, and the complex, in cooperation with T-cell factor 4 (TCF4), was required for transcriptional induction of genes encoding anti-apoptotic proteins, contributing to rescuing cardiomyocyte survival. In addition, PCA ameliorated mitochondrial dysfunction and prevented mitochondrial apoptosis dependent on PKM2. Consistently, PCA increased the binding of PKM2 to ß-catenin, improved heart contractive function, normalized heart structure and attenuated oxidative damage in mice subjected to artery ligation, but the protective effects were lost in Pkm2-deficient heart. Together, we showed that PCA regulated nuclear PKM2 function to rescue cardiomyocyte survival via ß-catenin/TCF4 signaling cascade, suggesting the potential of pharmacological intervention of PKM2 shuttle to protect the heart.

A statistical approach to evaluate the performance of cardiac biomarkers in predicting death due to acute myocardial infarction: time-dependent ROC curve

Background/aim: Myoglobin, cardiac troponin T, B-type natriuretic peptide (BNP), and creatine kinase isoenzyme MB (CK-MB) are frequently used biomarkers for evaluating risk of patients admitted to an emergency department with chest pain. Recently, time- dependent receiver operating characteristic (ROC) analysis has been used to evaluate the predictive power of biomarkers where disease status can change over time. We aimed to determine the best set of biomarkers that estimate cardiac death during follow-up time. We also obtained optimal cut-off values of these biomarkers, which differentiates between patients with and without risk of death. A web tool was developed to estimate time intervals in risk. Materials and methods: A total of 410 patients admitted to the emergency department with chest pain and shortness of breath were included. Cox regression analysis was used to determine an optimal set of biomarkers that can be used for estimating cardiac death and to combine the significant biomarkers. Time-dependent ROC analysis was performed for evaluating performances of significant biomarkers and a combined biomarker during 240 h. The bootstrap method was used to compare statistical significance and the Youden index was used to determine optimal cut-off values. Results : Myoglobin and BNP were significant by multivariate Cox regression analysis. Areas under the time-dependent ROC curves of myoglobin and BNP were about 0.80 during 240 h, and that of the combined biomarker (myoglobin + BNP) increased to 0.90 during the first 180 h. Conclusion: Although myoglobin is not clinically specific to a cardiac event, in our study both myoglobin and BNP were found to be statistically significant for estimating cardiac death. Using this combined biomarker may increase the power of prediction. Our web tool can be useful for evaluating the risk status of new patients and helping clinicians in making decisions.

[Development and application of CK-MB specific monoclonal antibodies].

The aim of this study is to develop creatine kinase isoenzyme MB (CK-MB) specific monoclonal antibodies (mAb), and characterize the monoclonal antibody and further development of quantitative detection assay for CK-MB. The BALB/c mice were immunized with purchased CK-MB antigen, then monoclonal antibodies were prepared according to conventional hybridoma technique and screened by indirect and capture ELISA method. To identify the epitopes and evaluate the classification, purchased creatine kinase isoenzyme MB (CK-MM/BB/MB) antigen was used to identify the epitopes, with immunoblotting and synthetic CK-MM and CK-BB in different linear epitope. A double antibody sandwich ELISA was applied to screen the mAb pairs for CK-MB detection, and the quantitative detection assay for CK-MB was developed. We used 74 cases of clinical specimens for comparison of our assay with Roche's CK-MB assay. We successfully developed 22 strains of hybridoms against CK-MB, these mAbs can be divided into linear, partial conformational CK-MB, CK-MM or CK-BB cross monoclonal antibody and CK-MB specific reaction with partial conformational monoclonal antibody, and CK-MB quantitative detection assay was developed by using partial conformational monoclonal antibody. The correlation coefficient factor r of our reagent and Roche's was 0.930 9. This study established a screening method for CK-MB partial conformational specific monoclonal antibody, and these monoclonal antibodies were analyzed and an established quantitative detection assay was developed. The new assay had a high concordance with Roche's.