Detection of coronary artery disease in patients with chest pain: A machine learning model based on magnetocardiography parameters.

BACKGROUD: Patients with chest pain and suspected of coronary artery disease(CAD) need further test to confirm the diagnosis. Magnetocardiography (MCG) is a non-invasive and emission-free technology which can detect and measure the weak magnetic fields created by the electrical activity of the heart. OBJECTIVE: This study aimed to investigate the usefulness of the 10 MCG parameters to detect CAD in patients with chest pain by means of a machine learning method of multilayer perceptron(MLP) neural network. METHODS: 209 patients who were suffering from chest pain and suspected of CAD were enrolled in this cross-sectional study. In all patients, 12-lead electrocardiography(ECG) and MCG test were performed before percutaneous coronary angiography(PCA). 10 MCG parameters were analyzed by MLP neural networks. RESULTS: 11 diagnostic models(M1 to M11) were established after MLP analysis. The accuracies ranged from 71.2% to 90.5%. Two models(M10 and M11) were further analyzed. The accuracy, sensitivity, specificity, PPV, NPV, PLR and NLR were 89.5%, 89.8%, 88.9%, 92.7%, 84.7%, 11.10 and 0.11, of M10, and were 90.0%, 91.4%, 87.7%, 92.1%, 86.6%, 7.43 and 0.10, of M11. CONCLUSIONS: By a method of MLP neural network, MCG is applicable in identifying CAD in patients with chest pain, which seems beneficial for detection of CAD.

Effectiveness of magnetocardiography to identify patients in need of coronary artery revascularization: a cross-sectional study.

BACKGROUND: Patients with angina-like symptoms need invasive or non-invasive angiography to determine whether revascularization is necessary. For patients in need of revascularization, undergoing coronary computed tomography angiography (CCTA) may delay the treatment of revascularization and increase exposure to contrast agents and radiation. The aim of this cross-sectional study was to accessed the effectiveness of magnetocardiography (MCG) to identify patients who should undergo coronary revascularization. METHODS: A total of 203 patients who were suffering from angina-like symptoms and underwent percutaneous coronary angiography (PCA) between July 27, 2015 and April 10, 2017 at the 8th Medical Center of Chinese PLA General Hospital, were enrolled in this cross-sectional study. In all patients, 12-lead electrocardiography (ECG) and MCG test were performed before PCA. For each subject. The value at every single sampling point was extracted from T wave of each MCG channel in time sequence. Pearson's correlation coefficients were calculated for each two T-waves. A binary logistic regression diagnosis model of these coefficients was established to identify patients in need of revascularization. RESULTS: Ten pairings of coefficients were entered into diagnostic regression model as covariates. The area under the receiver operating characteristic (ROC) curve (AUC) was 0.747 (95% CI: 0.680-0.815), and the asymptotic P value was less than 0.001. At the cut-off value of 0.55, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 72.9%, 65.9%, 74.8%, 63.6% and 69.9%, and the positive and negative post-test probabilities were 65.9% and 25.7%. The accuracy, sensitivity, specificity, PPV and NPV for 12-lead ECG were 67.0%, 62.7%, 63.5%, 70.5% and 55.1%, respectively. However, when those acute myocardial infarction (AMI) patients were ruled out from both groups, the MCG model had an accuracy of 68.2%, a sensitivity of 70.1%, a specificity of 66.3%, a PPV of 68.5% and an NPV of 67.9%. But, the accuracy, sensitivity, specificity, PPV and NPV for 12-lead ECG were 60.0%, 55.2%, 65.1%, 62.3% and 58.1%, respectively. CONCLUSIONS: Patients suffering from angina-like symptoms, with a logistic regression model value over 0.55, should be recommended for PCA.

Polydatin Attenuates H2O2-Induced Oxidative Stress via PKC Pathway.

Oxidative stress plays an important role in the pathogenesis of endothelial dysfunction, which is found to precede the development of diverse cardiovascular diseases (CVDs). The aim of this study was to observe the protective effects of PD against H2O2-induced oxidative stress injury (OSI) in human umbilical vein endothelial cells (HUVECs) and the possible mechanism of PD in OSI treatment. HUVECs were subjected to H2O2 in the absence or presence of PD. It turned out that PD improved cell viability and adhesive and migratory abilities, inhibited the release of lactate dehydrogenase (LDH) and reactive oxygen species (ROS), and elevated the content of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). TUNEL, fluorometric assays, and Western blotting showed that OSI upregulated the apoptosis ratio, the activity of caspase-3 and the level of proapoptotic protein Bax and decreased the level of antiapoptotic protein Bcl-2. However, PD treatment partially reversed these damage effects and Protein Kinase C (PKC) activation by thymeleatoxin (THX) in turn eliminated the antiapoptotic effect of PD. Furthermore, PD attenuated the H2O2-induced phosphorylation of PKCs α and δ and increased the phosphorylation of PKC ε. Our results indicated that PD might exert protective effects against OSI through various interactions with PKC pathway.

Earlier application of loading doses of aspirin and clopidogrel decreases rate of recurrent cardiovascular ischemic events for patients undergoing percutaneous coronary intervention.

BACKGROUND: Aspirin and clopidogrel resistance plays a significant role in the development of cardiovascular ischemic events for ninety patients undergoing percutaneous coronary intervention. Recent studies have indicated that increasing the dose of antiplatelet drugs maybe a potent method to improve the inhibition of platelet aggregation. METHODS: Thrombelastograph (TEG) determinations were used to evaluate the effect of antiplatelet therapy. According to the results, 90 patients were divided into three groups and given different doses of aspirin and clopidogrel. Thirty patients with both an inhibition rate of aspirin > 50% and an inhibition rate of clopidogrel > 50% were defined as the control group. Sixty patients with an inhibition rate for aspirin < 50% and an inhibition rate for clopidogrel < 50% were defined as the resistance group. Patients in resistance group were randomly assigned to be given a routine dose (100 mg aspirin plus 75 mg clopidogrel per day, which we called a resistance plus routine dose group, R + R) and a loading dose (200 mg aspirin and 150 mg clopidogrel per day, which we called resistance plus loading dose group, R + L) of antiplatelet therapy. A 12-month follow-up was observed to examine the change of inhibition rate of antiplatelet therapy and to estimate the relationship between inhibition rate and the occurrence of cardiovascular ischemic events. RESULTS: After 6 months of antiplatelet therapy, the inhibition rate of aspirin in the R + L group increased from (31.4 ± 3.7)% to (68.6 ± 7.1)%, which was significantly higher than that in R + R group, (51.9 ± 8.2)% (P < 0.01). The inhibition rate of clopidogrel in the R + L group increased from (22.1 ± 3.8)% to (60.2 ± 7.4)%, which was significantly higher than in the R + R group, (45.9 ± 4.3)% (P < 0.01). The occurrence rates of cardiovascular ischemic events, stent thrombosis, recurrent unstable angina and myocardial infarction in the R + R group were 20%, 36% and 17%, respectively. Occurrence was significantly increased compared with that in the control group, 3%, 10% and 1%, respectively (P < 0.01). In contrast, the occurrence rates in the R + L group (10%, 23% and 6%, respectively) were attenuated compared with those in the R + R group (P < 0.01), although still higher than in the control group (P < 0.01). CONCLUSIONS: Almost all of the cardiovascular ischemic events occurred in the first six months after percutaneous coronary intervention. According to the result of TEG determinations, earlier application of a loading dose of aspirin and clopidogrel can decrease the rate of recurrent cardiovascular ischemic events.

[Time-course changes of myogenic tone of mesenteric small artery in spontaneously hypertensive rat].

To investigate the time-course changes of myogenic tone in mesenteric small artery (MSA) of spontaneously hypertensive rat (SHR), thirty-two 7-week aged SHR rats were randomly divided into four groups (8, 16, 24, 32 weeks of age), and 32 sex- and age-matched Wistar-Kyoto (WKY) rats were assigned to control groups (CON). On the day of the study, segments of MSA were isolated and then cannulated to the two pipettes. Vascular diameters in response to the increased intraluminal pressure (from 0 mmHg to 150 mmHg, by 25 mmHg steps) of isolated MSA under no-flow conditions were recorded by a Pressure Myograph System both in physiologic salt solution (PSS) (active diameter, Da) and calcium-free PSS (passive diameter, Dp). The myogenic tone was calculated by (Dp - Da)/Dp × 100%. The tail artery pressure and vascular myogenic tone in SHR rats were significantly higher than those of the CON rats. Before 24 weeks, the vascular myogenic tone of MSA in SHR group increased monotonically, but at the end of 32 weeks, the vascular myogenic tone decreased in comparison with that in 24-week group, but was significantly higher than that in CON group. The tail artery pressure in SHR group slowly increased monotonically with increasing weeks of age, and the tail arterial pressure in 32-week group remained significantly higher than that in 24-week group. Vascular myogenic tone may participate in the whole process of hypertension. Early in the development of hypertension, because of the compensatory role of vascular tone, the vascular function has been partially compensated, thus guaranteeing adequate blood supply to organs. Late in the development of hypertension, because of the decompensation of myogenic tone, the vascular function is damaged, leading to the occurrence of severe vascular disease.

Clinical evaluation of a homemade enzyme-linked immunospot assay for the diagnosis of active tuberculosis in China.

The rapid diagnosis of smear-negative pulmonary tuberculosis (TB) and extrapulmonary TB is a significant problem in clinical practice. We evaluated the usefulness of a homemade enzyme-linked immunospot (ELISPOT) assay for the diagnosis of active TB in China. Seventy-eight healthy volunteers, 60 patients with active TB, and 32 patients with non-TB diseases were evaluated by tuberculin skin test (TST), an ELISPOT assay using a recombinant CFP-10/ESAT-6 fusion protein (rCFP-10/ESAT-6) as a stimulant, and T-SPOT-TB assay. The spot-forming cells (SFC) from 78 healthy subjects containing both PPD-positive and -negative persons was 3.7 ± 6.5. Among 31 diagnosed TB patients, the ELISPOT assay had a sensitivity of 67.7%, compared to a sensitivity of 77.4% for the T-SPOT-TB assay. The ELISPOT assay was more sensitive in smear-positive TB cases (76.9%) than in smear-negative TB cases (61.1%), while T-SPOT-TB had roughly similar sensitivities in smear-positive (76.9%) and smear-negative TB cases (77.8%). The specificity was 90.6% for ELISPOT and 78.1% for T-SPOT-TB among 32 subjects with non-TB diseases. The SFC of TB cases was significantly higher than that of non-TB disease cases, and the SFC of smear-positive TB cases was significantly higher than that of smear-negative TB cases (P < 0.01). We confirmed that the homemade ELISPOT assay appears more specific for the diagnosis of active TB than T-SPOT-TB. ELISPOT assay may be a useful method for the rapid diagnosis of active TB, especially for cases of smear-negative TB.

[Effects of bisoprolol on serum interleukin-6 and tumor necrosis factor-alpha level in patients with congestive heart failure].

AIM: To investigate the levels of the serum interleukin-6(IL-6)and tumor necrosis factor-alpha (TNF-alpha) in patients with congestive heart failure (CHF) and to evaluate the beneficial effects of beta-blockers on the above variables. METHODS: Studied 110 patients with CHF randomly treated with routine drugs (ACE Inhibitors, diuretics and vasodilator drugs, n=55) or additional beta-blocker bisoprolol (n=55). The levels of serum IL-6 and TNF-alpha in above patients with CHF at the different period of the course and in 50healthy humans were determined by radioimmunoassay. Simultaneously, the left ventricular ejective fraction (LVEF) of above patients were measured by nuclide ventricular imagery. RESULTS: Compared with control group, the levels of serum IL-6 and TNF-alpha in patients with CHF were significantly increased during the course. There was a significantly negative correlation between IL-6, TNF-alpha and LVEF at 12 weeks after the treatment, and there were significant differences of serum IL-6 and TNF-alpha level among NYHA II, III and IV in CHF patients. The level of serum IL-6 and TNF-alpha were decreased more significantly in the bisoprolol group than in the routine group (P<0.05 ) . CONCLUSION: Serum IL-6 and TNF-alpha level might play an important role in pathogenesis of CHF. Beta-blockers had suppress neurohumoral over activation in patients with CHF.