Presence of Severe Stenosis in Most Culprit Lesions of Patients with ST-segment Elevation Myocardial Infarction / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies revealed that culprit vessels of ST-segment elevation myocardial infarction (STEMI) were often related to mild or moderate stenosis. However, recent studies suggested that severe stenosis was primarily found in culprit lesions. The objective of this study was to analyze the stenosis severity of culprit lesions in STEMI patients and to clarify the paradoxical results.</p><p><b>METHODS</b>A total of 489 consecutive STEMI patients who underwent primary percutaneous coronary intervention were retrospectively studied from January 2012 to December 2014. The patients were divided into three groups based on stenosis severity using quantitative coronary analysis: Group A, 314 cases, stenosis ≥70%; Group B, 127 cases, stenosis 50-70%; and Group C, 48 cases, stenosis ≤50%. The clinical, demographic, and angiographic data of all groups were analyzed.</p><p><b>RESULTS</b>Patients in Group A exhibited a significantly higher prevalence of history of angina pectoris (95.9% vs. 62.5%, P< 0.001), multivessel disease (73.2% vs. 54.2%, P = 0.007), and lower cardiac ejection fraction (53.3 ± 8.6 vs. 56.8 ± 8.4, P= 0.009) than those in Group C. Multivariable analysis revealed that history of angina pectoris (odds ratio [OR]: 13.89, 95% confidence interval [CI]: 6.21-31.11) and multivessel disease (OR: 2.32, 95% CI: 1.25-4.31) were correlated with severe stenosis of the culprit lesion in Group A.</p><p><b>CONCLUSIONS</b>Most culprit lesions in STEMI patients were severe stenosis. These patients exhibited a higher prevalence of angina history and multivessel diseases.</p>

Effects of adenovirus-mediated gene transfer of ICOSIg fusion protein on experimental autoimmune myocarditis in Lewis rats / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the effects of adenovirus vector-mediated gene transfer of ICOSIg fusion protein on experimental autoimmune myocarditis (EAM) in Lewis rats.</p><p><b>METHODS</b>Expression vector containing ICOSIg (p-Adeno-ICOSIg) was constructed by fusion of human ICOS and IgGFc segment. Adenovirus vector was digested by PacI enzyme and transfected into HEK 293 cells. Adenovirus expressing ICOSIg was produced. EGFP was constructed into adenovirus vector and used as control. EAM was induced in Lewis rats by injection of porcine cardiac myosin. All immunized Lewis rats were divided into 4 groups. Group A (n = 15) and B (n = 15) received adenovirus containing ICOSIg on day 0 and day 14 respectively to study the effects of costimulatory molecules gene therapy on T cell activation and inflammation; group C (n = 10) and group D (n = 10) received adenovirus containing EGFP on day 0 and day 14 respectively as controls. Group E (n = 10) was normal controls that did not receive immunization. On day 28, all rats were killed after echocardiography examination. Histopathological examination was performed to observe myocardial inflammation. Protein levels of ICOS, ICOSL, B7-1 and B7-2 were detected by Western blot. INF-gamma, IL-2 and IL-4 mRNA were determined by realtime RT-PCR.</p><p><b>RESULTS</b>On day 28, cardiac function was significantly improved and myocardial inflammation significantly attenuated in group B compared to group A, C and D (all P < 0.05). B7-1 expression at protein level was significantly lower in group B than that of group C (P < 0.05). ICOS and ICOSL expressions at protein level were significantly decreased in both group A and B compared with group C and D (P < 0.05). IFN-gamma mRNA level significantly decreased and IL-4 mRNA significantly increased in group A and B compared to group C and D (P < 0.05).</p><p><b>CONCLUSIONS</b>Blockade of costimulatory pathway with gene therapy of ICOSIg alleviated autoimmune inflammatory damage and improved cardiac function in Lewis rats with EAM. Down-regulated costimulatory molecules in the myocardium and reduced inflammatory cytokine secretion might be responsible for the beneficial effects of ICOSIg in this model.</p>

Effects of NG-nitro-L-arginine methyl ester on hemodynamics and beta-adrenoreceptors mRNA in rats with heart failure after beta3-adrenergic receptors agonist injection / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the effects of different doses of N(G)-nitro-L-arginine methyl ester (L-NAME) on hemodynamics, cyclic guanosine monophosphate (cGMP) production and the level of beta-adrenergic receptors (beta-ARs) mRNA in a heart failure rat model after BRL-37344 (beta(3)-ARs agonist) injection. Meanwhile, to investigate the influence of beta(3)-ARs and L-NAME on signal transduction in failing heart.</p><p><b>METHODS</b>The rats were randomly divided into six groups, control group (group I), Iso (isoproterenol) group (group II), Iso + BRL group (group III), Iso + BRL + low dose of L-NAME group (5 mg/kg, group IV), Iso + BRL + moderate dose of L-NAME group (50 mg/kg, group V), Iso + BRL + high dose of L-NAME group (100 mg/kg, group VI). The hemodynamics [left ventricular end systolic pressure (LVESP), +/- dp/dt, left ventricular end diastolic pressure (LVEDP)], cardiac cGMP and the levels of beta(1)-, beta(2)-, and beta(3)-ARs mRNA were measured.</p><p><b>RESULTS</b>(1) LVESP, +/- dp/dt values in group II were significantly lower, and LVEDP was significantly higher than that in group I (except -dp/dt P < 0.05, the rest were P < 0.01). Comparing with group II, group III had lower -dp/dt value and LVESP, higher LVEDP (P < 0.05). The level of +dp/dt had a trend to be lower but lacked statistical significance between two groups. The value of +/- dp/dt got higher and LVEDP got lower along with higher dose of L-NAME, but a large dose of L-NAME had more deteriorated cardiac functions. (2) The cardiac cGMP in group I, II and III had a higher tendency (P < 0.01). The tendency of cardiac cGMP in group IV, V and VI was inversed with the dose of L-NAME. After a large dose of L-NAME was applied, cGMP returned to the same level as Group I. (3) Among groups I, II and III, the level of beta(1)-AR mRNA was the highest in group I and the lowest in group III (P < 0.01). The levels of beta(2)-AR mRNA were also tended to be lower among three groups but with no significance. While the level of beta(3)-AR mRNA was the highest in group III. The levels of beta-AR mRNA were all the same in group VI, V and VI.</p><p><b>CONCLUSIONS</b>The negative inotropic effect of beta(3)-ARs stimulation was mediated by activation of the NOS pathway. L-NAME blocked beta(3)-ARs agonist negative chronotropic effect on failing heart partly and improved hemodynamics, but a large dose of L-NAME had more deteriorated cardiac functions.</p>

Effects of Losartan on acute atrial electrical remodeling / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Atrial electrical remodeling (AER) contributes to the maintainance of atrial fibrillation (AF). This study was to compare the effects of Losartan with those of Diltiazem on tachycardia-induced acute AER in rabbits.</p><p><b>METHODS</b>Twenty-one rabbits paced with maximal atrial capture rate for 3 hours in the right atrium (RA) were randomly divided into saline group, Diltiazem group and Losartan group. After autonomic blockage, we measured atrial effective refractory period (AERP), AERP rate adapting feature, AERP dispersion and RA conduction time at basic cycle lengths (BCLs) of 200 ms and 150 ms at baseline, 0.5 hour, 1 hour, 2 and 3 hours after rapid atrial pacing.</p><p><b>RESULTS</b>In the saline group, there was a prompt decrease in AERP as a result of rapid atrial pacing, and AERP200 and AERP150 were shortened sharply within 0.5 hour of pacing (30.2 +/- 10.5 ms and 24.1 +/- 9.1 ms, respectively). The AERP did not change dramatically in the Diltiazem and Losartan groups. In the saline group, the value of (AERP200-AERP150)/50 ms in high RA was 0.17 +/- 0.08 at baseline and became significantly smaller at 0.5 hour (0.08 +/- 0.06), 1 hour (0.09 +/- 0.06), 2 hours (0.08 +/- 0.04) and 3 hours (0.09 +/- 0.05) (all P < 0.05), suggesting a reduction of rate adaptation of AERP. The value of (AERP200-AERP150)/50 ms in high RA did not change during the 3 hours of pacing in both Diltiazem and Losartan groups. In the saline group, AERP dispersion increased significantly at 2 and 3 hours (P < 0.05). However, Diltiazem could not prevent the increase of AERP dispersion at 3 hours (P < 0.05). During Losartan infusion, the AERP dispersion was no longer increased after rapid atrial pacing. There was no significant difference in RA conduction time among the three groups.</p><p><b>CONCLUSION</b>Like calcium antagonist Diltiazem, Losartan could prevent AERP shortening and preserve rate adaptation of AERP after rapid atrial pacing. Losartan is more effective than Diltiazem in inhibiting the increase of AERP dispersion.</p>