Predictive Value of CHA2DS2-VASc Score for Contrast-induced Nephropathy After Elective Percutaneous Coronary Intervention in Patients With Coronary Heart Disease / 中国循环杂志

Objectives: To investigate the predictive value of CHA2DS2-VASc score for contrast induced nephropathy (CIN) after percutaneous coronary intervention in patients with coronary heart disease. Methods: A total of 356 patients undergoing elective percutaneous coronary intervention were enrolled in this study. The patients were divided into two groups according to the CHA2DS2-VASc score: CHA2DS2-VASc score ≥ 3 (n=153) and ≤ 2 (n=203). Baseline data, incidence of CIN and major adverse cardiovascular events were analyzed and compared between the two groups. The predictive effect of CHA2DS2-VASc score was analyzed with receiver operating characteristic curve (ROC) and logistic regression analysis. Results: Left ventricular ejection fraction was significantly lower, baseline serum creatinine value was significantly higher, coronary lesions were more complex, contrast agent dosage used was significantly larger and the incidence of CIN was significantly higher in patients of the CHA2DS2-VASc score ≥ 3 group than in patients of CHA2DS2-VASc score ≤ 2 group (all Pvalues<0.05). Multivariate logistic regression analysis showed that CHA2DS2-VASc score≥3 was an independent predictor of CIN (OR=2.152, 95% CI: 1.261-3.987, P=0.032). The area under the curve of ROC of CHA2DS2-VASc score ≥ 3 for predicting CIN was 0.749 (sensitivity 76.9%, specificity 73.0%). Conclusions: CHA2DS2-VASc score could predict the CIN after percutaneous coronary intervention in patients with coronary heart disease, which could help us identify the high-risk patients of CIN and take preventive measures to reduce the incidence of CIN post percutaneous coronary intervention.

Cardiac protection from myocardial ischemic postconditioning and remote postconditioning during myocardial ischemia/reperfusion injury in rabbits / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To observe whether there are some differences between myocardial postconditioning and remote postconditioning, and whether there is additional cardiac protection when they are used combined during myocardial ischemia/reperfusion injury in rabbits.</p><p><b>METHODS</b>Thirty healthy New Zealand rabbits which were randomly divided into 5 groups (n = 5): ischemic control group (CON), sham operation group (Sham), myocardial postconditioning group (MPostC), remote postconditioning group (RPostC), myocardial postconditioning plus remote postconditioning group (MPostC + RPostC). Acute myocardial infarction was induced by 45 minutes occlusion on left circumflex coronary artery (LCX) and 2 hours reperfusion in all anesthetized open-chest rabbits except the Sham, the coronary occlusion and reperfusion were determined by changes of ECG and cardiac color. Skeletal muscle ischemia model was induced by extrinsic iliac arteries occlusion and reperfusion with artery clamps. The condition that the extrinsic iliac arteries were occluded or reperfused could be tested by according to the distal arterial pulse. Plasma creatine kinase (CPK) activity and lactate dehydrogenase (LDH) activity were measured at baseline, the end of ischemia, after 1 hour and 2 hours of reperfusion respectively. The extent of myocardial infarction was assessed by triphenyltetrazolium (TTC) staining and measured by area ratio of AN/AAR.</p><p><b>RESULTS</b>Compared with the Con, myocardial infarct size was significantly reduced in MPostC and RpostC group (P < 0.05). But there was no significant difference between MPostC and RPostC group. Combined MPostC and RPostC markedly enhanced myocardial protection (P < 0.05). The trend of CPK and LDH release was similar to the trend of myocardial infarct size.</p><p><b>CONCLUSION</b>Both MPostC and RPostC induced cardiac protection. There was no significant difference between MPostC and RPostC. Combined MPostC and RPostC induced markedly additive effect on myocardial protection.</p>

Cardioprotective effects of limb ischemic postconditioning by different strength and time in rabbits / 中国应用生理学杂志

<p><b>OBJECTIVE</b>In this study, we try to find the better protocol of limb ischemia postconditioning by observing different protective effects of limb ischemic postconditioning (different strength and time windows in rabbits).</p><p><b>METHODS</b>42 healthy New Zealand rabbits were randomly divided into 7 groups (n = 6): Sham; Control (CON); Skeletal muscle postconditioning (SP); 6 min-delayed skeletal muscle postconditioning (6M-DSP); 1 min-delayed skeletal muscle postconditioning (1M-DSP); Strengthen skeletal muscle postconditioning (SSP); Weakened skeletal muscle postconditioning (WSP). Acute ischemia/reperfusion (I/R) model was induced by 45 minutes occlusion on left circumflex coronary artery (LCX) and 2 hours reperfusion in all anesthetized open-chest rabbits except the Sham. Limb ischemia was induced by external iliac arteries occlusion and reperfusion through artery clamps. The extent of myocardial infarction was assessed by triphenyltetrazolium (TTC) staining. Blood serum creatine kinase (CK) activity and lactate dehydrogenase (LDH) activity were measured at baseline,the end of ischemia, after 1 hour and 2 hours of reperfusion respectively.</p><p><b>RESULTS</b>Compared with the CON, the weight ratio and area ratio of myocardial infarction size were significantly decreased by 49.97% and 43.78% in SP, by 42.32% and 42.68% in 1M-DSP, by 48.36% and 48.86% in SSP (P < 0.05). But there was no significant difference between SP and 1M-DSP and SSP (P > 0.05). Otherwise, compared with the CON, myocardial infarct size was not significantly reduced in 6M-DSP or WSP (P > 0.05). The change of CK was similar to the trend of myocardial infarct size.</p><p><b>CONCLUSION</b>The limb ischemia strength of 5 mini/1 minR x 1 cycle could significantly reduce the myocardial ischemia/ reperfusion injury in rabbits, if it was achieved before myocardial reperfusion.</p>

Effects of rabbit limbs ischemia/ reperfusion on myocardial necrosis and apoptosis / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of rabbit limbs ischemia/reperfusion on myocardial necrosis and apoptosis in vivo.</p><p><b>METHODS</b>Thirty-six healthy new zealand rabbits were randomly divided into 3 groups: (1) Sham group; (2) I/R(Ischemia/reperfusion) group; (3) RPostC (remote postconditioning) group. The activity of blood serum creatine kinase (CK) and lactate dehydrogenase (LDH) were measured at baseline, the end of ischemia after 60 min and 120 min of reperfusion respectively. The extent of myocardial ischemia and the scope of myocardial infarction were assessed by evans blue and Triphenyl tetrazolium chloride (TTC). The myocardial cell's apoptosis at the area of myocardial ischemia was estimated by Tunel. Protein expression of caspase-3, Bcl-2 and Bax in myocardial ischemic area were analyzed with the method of immunohistochemistry.</p><p><b>RESULTS</b>Compared with I/R group, the myocardial infarct size and the CK activity were significantly reduced in RPostC group. The Tunel positive index of RPostC group in ischemic myocardium was significantly lower than that in I/R group (21.79% +/- 1.07% vs 35.81% +/- 1.10%, P < 0.05). Caspase-3 positive cells index was calculated with randomly selected five regions in each slide and then the positive cells in per hundred cells were calculated. The RPostC group of caspase-3 positive cells was significantly lower than that in I/ R group(25.03% +/- 1.16% as 39% +/- 2.43%, P < 0.05). Compared with the sham group, the Bax protein expression index and the Bcl-2 protein expression index of I/R group and RPostC group were increased. The Bax/Bcl-2 ratio of RPostC group decreased, while it was increased in I/R. Compared with the I/R group, the Bax protein expression and Bax/Bcl-2 ratio of RPostC group significantly reduced, but the expression index of Bcl-2 ratio was significantly increased, the differences were statistically significant.</p><p><b>CONCLUSION</b>Limbs ischemia/postconditioning could significantly reduce necrosis and apoptosis of ischemia/reperfusion myocardium. The mechanism of reducing the myocardial cell apoptosis may have relation to inhibiting the activation of pro-apoptotic gene caspase-3 and increased expression of Bcl-2.</p>

Impact of application time of aspirin and clopidogrel on platelet aggregation in patients with acute coronary syndrome / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the impact of various application time of aspirin and clopidogrel on the circadian rhythm changes of platelet aggregation in patients with acute coronary syndrome.</p><p><b>METHODS</b>Patients with acute coronary syndrome were divided into day-time (8:00) and night-time (20:00) medication group (n = 15 each). After plasma concentration reached steady state, platelet aggregation was assessed at 5 time points within 24 hours with a mobile four-channel whole blood impedance aggregometer. The platelet aggregation was induced by ADP and arachidonic acid. Thereafter, the two groups were exchanged and platelet aggregation was assessed in the same way post plasma steady state.</p><p><b>RESULTS</b>Arachidonic acid-induced platelet aggregation was the highest at 10:00 Am [(7.96 +/- 3.64) ohm] and the lowest at 0:00 [(6.12 +/- 3.29) ohm, P > 0.05] in day-time group. Platelet aggregation was the highest at 20:00 [(9.40 +/- 5.39) ohm] and the lowest at 10:00 [(5.46 +/- 3.93) ohm], P < 0.05). ADP-induced platelet aggregation was the highest at 10:00 and the lowest at 16:00 in day-time group (P > 0.05) and was the highest at 20:00 and the lowest at 10:00 in night-time group (P > 0.05). Platelet aggregation induced by two inducers was significantly higher at 10:00 in day-time group compared to values in night-time group (all P < 0.05).</p><p><b>CONCLUSION</b>Taking aspirin and clopidogrel at 20:00 was superior to taking the same medications at 8:00 for inhibiting peak platelet aggregation in the morning.</p>

Effects of pravastatin on the expression of endothelin induced by aldosterone in rat cardiac fibroblasts / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effects of pravastatin on endothelin(ET) expression induced by aldosterone in cultured neonatal rat cardiac fibroblasts.</p><p><b>METHODS</b>ET concentration in conditioned medium was measured by radioimmunoassay, intracellular ET-1 level was evaluated by flow cytometry, and the expression of preproendothelin-1 (ppET-1) was detected and quantified using reverse transcriptase-polymerase chain reaction (RT-PCR) method.</p><p><b>RESULTS</b>The cardiac fibroblasts, treated with aldosterone at 107 mol/L, significantly up-regulated ppET-1 mRNA expression, as well as ET-1 synthesis and release. Pravastatin (10(-5), 10(-4), 10(-3) mol/L) dose-dependently blocked these effects. In contrast, pravastatin-induced inhibitory effects were reversed in the presence of mevalonate.</p><p><b>CONCLUSION</b>Pravastatin down-regulated ppET-1 mRNA expression, as well as ET-1 synthesis and release induced by aldosterone in a process specifically related to mevalonate in cardiac fibroblasts.</p>

Single plane Simpson's method for measurement of right ventricular volume by X-ray ventriculography / 中华心血管病杂志

<p><b>OBJECTIVE</b>To study the validity of single plane Simpson's method with conventional X-ray ventriculography for estimation of right ventricular (RV) volume.</p><p><b>METHODS</b>Fifteen human RV casts were obtained from 15 subjects who died from non-cardiac causes within 24 hours after death. These casts were photographed respectively and their volumes were calculated by using the single plane Simpson's method based on a new half-circle model. The actual RV cast volumes were determined by water displacement method.</p><p><b>RESULTS</b>The actual RV volume was (64.23 +/- 24.51) ml and the calculated volume was (58.04 +/- 24.45) ml. The calculated RV volume underestimated the actual volume by (6.19 +/- 12.38) ml, but there was no significant difference between the actual and the calculated RV volume (P > 0.05). There was a significant correlation between the actual cast volume and the calculated volume (r = 0.983, P < 0.01). The regression equation was: RV actual volume = 1.074 x (RV calculated volume).</p><p><b>CONCLUSION</b>RV volume calculated by single plane Simpson's method with conventional X-ray ventriculography is accurate and deserves further study.</p>