BACKGROUND: High on-treatment platelet reactivity (HTPR) has been suggested as a risk factor for patients with ischemic vascular disease. We explored a predictive model of platelet reactivity to clopidogrel and the relationship with clinical outcomes. METHODS: A total of 441 patients were included. Platelet reactivity was measured by light transmittance aggregometry after receiving dual antiplatelet therapy. HTPR was defined by the consensus cutoff of maximal platelet aggregation >46% by light transmittance aggregometry. CYP2C19 loss-of-function polymorphisms were identified by DNA microarray analysis. The data were compared by binary logistic regression to find the risk factors. The primary endpoint was major adverse clinical events (MACEs), and patients were followed for a median time of 29 months. Survival curves were constructed with Kaplan-Meier estimates and compared by log-rank tests between the patients with HTPR and non-HTPR. RESULTS: The rate of HTPR was 17.2%. Logistic regression identified the following predictors of HTPR: age, therapy regimen, body mass index, diabetes history, CYP2C192, or CYP2C193 variant. The area under the curve of receiver operating characteristic for the HTPR predictive model was 0.793 (95% confidence interval: 0.738-0.848). Kaplan-Meier analysis showed that patients with HTPR had a higher incidence of MACE than those with non-HTPR (21.1% vs. 9.9%; χ = 7.572, P = 0.010). CONCLUSIONS Our results suggest that advanced age, higher body mass index, treatment with regular dual antiplatelet therapy, diabetes, and CYP2C192 or CYP2C193 carriers are significantly associated with HTPR to clopidogrel. The predictive model of HTPR has useful discrimination and good calibration and may predict long-term MACE.
Aged ; Blood Platelets ; drug effects ; Clopidogrel ; pharmacology ; therapeutic use ; Coronary Artery Disease ; metabolism ; prevention & control ; Cytochrome P-450 CYP2C19 ; metabolism ; Female ; Genotype ; Glycated Hemoglobin A ; metabolism ; Humans ; Kaplan-Meier Estimate ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Myocardial Ischemia ; metabolism ; prevention & control ; Regression Analysis

Dental surgery is very common, and it is important for our dental colleagues to understand the medical history and chronic medications of our co-managed patients. Antibiotic prophylaxis is currently recommended only for patients at high risk for infective endocarditis when undergoing high-risk dental procedures. Good dental hygiene can prevent more infective endocarditis than prophylactic antibiotic therapy, as transient bacteraemia is common in daily activities such as the brushing and flossing of teeth. Most dental surgeries can generally be performed on patients taking a daily dose of aspirin, but the dentist must be able to assess the risk-benefit ratio of employing local measures of haemostasis versus stopping the antiplatelet therapy. Patients on antiplatelet with recent coronary artery stenting should be referred to their primary cardiologist regarding the cessation of these agents before any surgery.
Angioplasty ; Antibiotic Prophylaxis ; methods ; Aspirin ; therapeutic use ; Dental Care for Chronically Ill ; methods ; Dentists ; Drug Interactions ; Endocarditis ; prevention & control ; Humans ; Hyperlipidemias ; complications ; Macrolides ; adverse effects ; Male ; Mitral Valve Prolapse ; complications ; Myocardial Ischemia ; complications ; Platelet Aggregation Inhibitors ; adverse effects ; Simvastatin ; adverse effects ; Streptococcal Infections ; prevention & control ; Tooth Extraction ; methods ; Viridans Streptococci ; metabolism

OBJECTIVETo assess the protective effect of exogenous hydrogen sulfide (H₂S) against myocardial injury after skeletal muscle ischemia/reperfusion (IR) in rats and explore the mechanism.

METHODSThirty-one Wistar rats were randomized into normal control (n=8), IR group (n=8, with a 4-h reperfusion following a 4-h ischemia of the bilateral hindlimbs induced using a tourniquet), NaHS group (n=8, with IR and intraperitoneal injection of 14 µmol/kg NaHS), and DL-propargylglycine (PPG) group (n=7, with IR and intraperitoneal injection of 50 mg/kg PPG). The plasma levels of CK-MB and the levels of MPO, TNF-α, MDA, T-SOD, and CuZn-SOD in the plasma and myocardial tissues were measured. The expression of TNF-α in the myocardium was examined using immunohistochemistry. RESULTS Skeletal muscle IR induced significantly increased plasma CK-MB level (P<0.05) and the levels of MPO, TNF-α, and MDA in the plasma and myocardium, and significantly decreased plasma and myocardial levels of T-SOD and CuZn-SOD (P<0.05). NaHS treatment significantly decreased plasma CK-MB level (P<0.05), reduced plasma and myocardial levels of MPO, TNF-α, and MDA, and increased plasma and myocardial T-SOD and CuZn-SOD in rats with IR (P<0.05), whereas PPG treatment did not produce any obvious responses (P>0.05). Immunohistochemistry showed an obviously reduced expression of TNF-α in the myocardium in rats with NaHS treatment compared with those in IR group.

CONCLUSIONH₂S treatment can alleviate myocardial injury induced by skeletal muscle IR in rats by inhibiting the inflammatory cytokines and oxidative stress.

Animals ; Creatine Kinase, MB Form ; metabolism ; Disease Models, Animal ; Hydrogen Sulfide ; pharmacology ; Ischemia ; metabolism ; Male ; Malondialdehyde ; metabolism ; Muscle, Skeletal ; blood supply ; metabolism ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Oxidative Stress ; Peroxidase ; metabolism ; Rats ; Rats, Wistar ; Superoxide Dismutase ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo study the protection effects and the mechanisms of Huoxue Anxin Recipe (HAR) on acute myocardial infarction (AMI) rats.

METHODSThe AMI Wistar rat model was prepared by ligating the left anterior descending coronary artery. By taking elantan long as the positive control drug, HAR was extracted from Chinese herbs by modern pharmacological methods and composed according to theories of Chinese medicine (CM). The medication time started from the day of modeling to the 21st day of the modeling. The heart function, the morphological changes of the heart, changes in the mRNA and protein levels of toll like receptor 4 nuclear factor kappa B tumor necrosis factor alpha (TLR4-NFkappaB-TNFalpha) pathway were observed.

RESULTSCompared with the sham-operation group, the ejection fraction (EF) and left ventricular fractional shortening (FS) significantly decreased (P < 0.01), the left ventricular intemal dimension end-diastolic (LVIDd) and left ventricular internal dimension end-systolic (LVIDs) significantly increased (P < 0.01), the mRNA and protein levels of TLR4-NFkappaB-TNFalpha channel significantly increased in the model group (P < 0.01). The infarction in the front wall of the left ventricle was obviously seen, accompanied with severe inflammatory cell infiltration and collagen deposition in model group. Compared with the model group, the EF and FS significantly increased, LVIDd and LVIDs significantly decreased in the positive control group, the high and low dose HAR groups (P < 0.05, P < 0.01). The infracted area of the front wall of the left ventricle was obviously contracted. The inflammatory cell infiltration and collagen deposition were obviously alleviated. In the high and low dose HAR groups, the mRNA and protein expression levels of TLR4-NFkappaB-TNFalpha significantly decreased (P < 0.05, P < 0.01), but no inhibition was found in the positive control group.

CONCLUSIONSHAR could significantly improve the morphological structures and functional abnormality induced by myocardial ischemia in AMI rats. Its effects was correlated with inhibiting TLR4-NFkappaB-TNFalpha pathway.

Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Male ; Myocardial Infarction ; drug therapy ; metabolism ; Myocardial Ischemia ; metabolism ; prevention & control ; NF-kappa B ; metabolism ; Rats ; Rats, Wistar ; Toll-Like Receptor 4 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo evaluate the anti-apoptotic effect of aldehyde dehydrogenase 2 (ALDH2) on myocardial ischemia/reperfusion (I/R) injury in diabetic rats.

METHODSNormal male SD rats were divided into normal, diabetes and ethanol (the agonist of ALDH2) + diabetes groups. In the latter two groups, diabetes was induced by an intraperitoneal injection of 55 mg/kg STZ. Four weeks after the modeling, myocardial I/R was mimicked ex vivo, and lactate dehydrogenase (LDH) content in the coronary flow was determined. The activities of caspase-3 and ALDH2 were evaluated, and the expressions of Bcl-2 and Bax mRNA in the left anterior myocardium were detected using RT-PCR.

RESULTSIn diabetic group, LDH release and caspase-3 activity were increased, while ALDH2 activity and Bcl-2/Bax mRNA expression were decreased as compared to those in normal control group. Compared with the diabetic group, ALDH2 agonist ethanol significantly reduced LDH release and caspase-3 activity, increased ALDH2 activity and Bcl-2/Bax mRNA expression.

CONCLUSIONIn diabetic rats, enhanced ALDH2 expression can offer mycardial protection possibly in relation to suppress cell apoptosis.

Aldehyde Dehydrogenase ; metabolism ; Aldehyde Dehydrogenase, Mitochondrial ; Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Diabetes Mellitus, Experimental ; complications ; enzymology ; Ethanol ; pharmacology ; Male ; Mitochondrial Proteins ; agonists ; metabolism ; Myocardial Ischemia ; enzymology ; etiology ; Myocardial Reperfusion Injury ; enzymology ; pathology ; prevention & control ; Myocardium ; enzymology ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo investigate whether the release of nitric oxide (NO) was involved in the cardioprotection of ethanol postconditioning in isolated rat hearts.

METHODSHearts isolated from male SD rats were subjected to 30 min of regional ischemia (occlusion of left anterior descending artery) followed by 120 min of reperfusion. Ethanol postconditioning was fulfilled through perfusion of 50 mmol/L ethanol for 15 min (at the end of cardiac ischemia for 5 min and at the beginning of reperfusion for 10 min). The rats were divided into five groups: normal, ischemia and reperfusion, ethanol postconditioning, ethanol postconditioning + L-nitro-arginine-methylester (L-NAME) and ethanol postconditioning + atractyloside. The ventricular hemodynamic parameters and lactate dehydrogenase (LDH) release during reperfusion were measured. The infarct size was measured by TTC staining method and NO content was measured by nitric acid reductase method. The expressions of Bcl-2 and Bax mRNA were detected by RT-PCR analysis.

RESULTSIn contrast to ischemia and reperfusion, ethanol postconditioning improved left ventricular developed pressure, rate pressure product during reperfusion, reduced LDH release and infarct size. NO content was decreased. The ratio of Bcl-2/Bax was increased. Administration of nitric oxide synthase inhibitor L-NAME or mitochondrial permeability transition pore opener atractyloside both attenuated the role of ethanol postconditioning, which inhibited the recovery of hemodynamic parameters, the decreases of LDH and infarct size. NO content was decreased further. The ratio of Bcl-2/Bax was decreased.

CONCLUSIONThe cardioprotection of ethanol postconditioning may be associated with reducing nitric oxide release, inhibiting the opening of mitochondrial permeability transition pore and decreasing the happening of apoptosis.

Animals ; Ethanol ; therapeutic use ; In Vitro Techniques ; Ischemic Postconditioning ; Male ; Mitochondria, Heart ; metabolism ; Myocardial Ischemia ; metabolism ; prevention & control ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Myocardium ; metabolism ; Nitric Oxide ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To determine the effect of Gingkgo biloba leaf extract (EGb761) induced delayed preconditioning on cytochrome c oxidase (CcO) expression during myocardial ischemia-reperfusion in rats. METHODS: Four groups (10 in each) of Sprague-Dawley male rats were studied. In the sham group, the rats received no treatment. Rats in the ischemia-reperfusion (IR) group were treated with NS (1.0 mL/kg intravenously) 24 h before ischemia. Rats in the M group were treated with EGb761 (100 mg/kg intravenously) 24 h before the ischemia. In the D group , EGb761-treated rats that received the 5-hydroxydecanoate (5-HD), an inhibitor of mitochondrial KATP channels 15 min before the ischemia. The IR, M, and D groups were subjected to ischemia by 30 min of coronary artery occlusion before 2 h of reperfusion. At the end of the reperfusion, myocardial infarct size was measured. CcO was measured by Western blot. The myocardial ultrastructure was observed under the electron microscope. RESULTS: The infarct size was significantly smaller in the M group [(23.78 ± 4.82)%] than in the I/R group [(37.87 ± 5.92)%] (P<0.05). The CcO protein expression in the myocardium was significantly higher in the M group than in the I/R group(P<0.05). Microscopic examination showed less myocardial damage in the M group than that in the I/R group. The infarct size, CcO protein expression, and myocardial damage had no significant difference between the D group and the I/R group (P>0.05). CONCLUSION EGb761 induced delayed preconditioning attenuates myocardial ischemia-reperfusion injury possibly through up-regulating CcO expression in rats.
Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Electron Transport Complex IV ; metabolism ; Ginkgo biloba ; chemistry ; Ischemic Postconditioning ; methods ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Ischemia ; physiopathology ; Myocardial Reperfusion Injury ; metabolism ; prevention & control ; Phytotherapy ; Plant Leaves ; chemistry ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the effect of hydrogen sulfide (H2S) on mitochondrial function in acute myocardial ischemia in rats.

METHODSAcute myocardial ischemia models were established by ligating the left anterior descending coronary artery (LADC) of rats. Fourty-eight male SD rats were randomly divided into 6 groups (n = 8): sham operation group, ischemia group, ischemia + sodium hydrosulfide (NaHS) low, middle and high dose groups and ischemia + DL-proparglycine(PPG) group. The ultrastructures of myocardial mitochondria were observed with electron microscope. The content of H2S in plasma and the activity of cystathionine-gamma-lyase (CSE) in myocardial tissue of rats were respectively detected. The swelling and activity of myocardial mitochondria were determined. The activities of ATPase, GSH-Px, SOD and the content of malondial-dehyde (MDA) in myocardial mitochondria of rats were also measured.

RESULTSCompared with those of the sham operation group, the content of H2S in plasma, the activity of CSE in myocardial tissue and the activity of myocardium mitochondria were significantly decreased. The activities of ATPase, SOD, GSH-Px in myocardial mitochondria were significantly decreased, The content of malondial dehyde(MDA) in myocardial mitochondria and the swelling of mitochondria were distinctly increased in the ischemia group (P < 0.01). Compared with those of the ischemia group, the content of H2S in plasma and the activity of CSE in myocardial tissue were increased, and the activities of mitochondria, ATPase, SOD, and GSH-Px in myocardial mitochondria were significantly increased in ischemia + NaHS low, middle and high-dose groups; the swelling of mitochondria and the content of MDA in myocardial mitochondria were significantly decreased in ischemia + NaHS middle and high-dose groups (P < 0.05 or P < 0.01). The administration of PPG could partially reduce the myocardial protection of hydrogen sulfide (P < 0.05 or P < 0.01).

CONCLUSIONIt could be concluded that the administration of hydrogen sulfide could enhance the activities of mitochondrial ATPase, SOD, GSH-Px, decrease the level of mitochondrial lipid peroxidation, and play a protective effect against acute myocardial ischemia.

Adenosine Triphosphatases ; metabolism ; Animals ; Glutathione Peroxidase ; metabolism ; Hydrogen Sulfide ; pharmacology ; Lipid Peroxidation ; drug effects ; Male ; Mitochondria, Heart ; drug effects ; metabolism ; physiology ; Myocardial Ischemia ; physiopathology ; prevention & control ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

OBJECTIVETo study the protective effect of Shenfu (Chinese traditional medicine) injections on myocardial ischemia/reperfusion (I/R) injury in rabbits.

METHODSThirty rabbits were divided into three groups (n = 10) randomly: control group, myocardial ischemia/ reperfusion group (MI/RI) and Shenfu injections extract group, three groups of rabbits were fed respectively with standard diet. After giving medicine 10 minutes, the myocardial ischemia/reperfusion injury animal model was established by ligaturing rabbits left ventricutar branch of coronary artery, and observing the changes of enzyme/hemodynamics during myocardial ischemia/reperfusion.

RESULTSIn model group myocardial function of shrink went down, the amount of malondialdehyde (MDA) was higher, the activity of superoxide dismutase (SOD), glutathine peroxidease (GSH-Px), Na(+) -K(+) -ATP and Ca(2+) -ATP were lower, lactic dehydrogenase (LDH) and creatine kinase(CK) were released compared with those in model group. Shenfu injections could recover left ventricular systolic pressure (LVSP) and +/- dp/dt(max), decrease left ventricular end-diastolic pressure(LVEDP), inhibit the increasing of MDA, LDH and CK, and increase the activaty of SOD, GSH-PX, Na(+) -K(+) -ATP and Ca(2+) -ATP.

CONCLUSIONShenfu injections can obviously protect myocardial ischemia/reperfusion injury.

Animals ; Calcium-Transporting ATPases ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Glutathione Peroxidase ; metabolism ; Hemodynamics ; drug effects ; Male ; Myocardial Ischemia ; physiopathology ; Myocardial Reperfusion Injury ; prevention & control ; Myocardium ; enzymology ; Rabbits ; Random Allocation ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Superoxide Dismutase ; metabolism

OBJECTIVETo investigate the effect of S-allyl-L-cysteine (SAC) on isolated rat heart subject to ischemia/reperfusion(I/R) injury and the mechanisms.

METHODSThe isolated perfused rat hearts on a Langendorff apparatus were subjected to global ischemia for 30 min and followed by 120 min of reperfusion. Hemodynamic index, the production of formazan and the level of lactate dehydrogenase (LDH) in the coronary effluent were determined. Superoxide dismutase (SOD) and reactive oxygen species (ROS) in myocardial homogenates were measured.

RESULTSCompared with I/R group, the hemodynamics were greatly improved, the production of formazan was increased, and LDH level in effluent was reduced in SAC group. SAC improved the SOD activity and significantly decreased the level of ROS. In addition, threonine (Thr) attenuated the protective effect of SAC significantly.

CONCLUSIONSAC has protective effect against myocardial ischemia/reperfusion injury on rats. The possible mechanism is that SAC be transported into the cell through alanine-serine-cysteine-transporter 1 (ASCT-1) improves SOD activity and reduces the level of ROS.

Animals ; Cysteine ; analogs & derivatives ; pharmacology ; In Vitro Techniques ; Male ; Myocardial Ischemia ; physiopathology ; Myocardial Reperfusion Injury ; physiopathology ; prevention & control ; Protective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism