Post-exercise heart rate recovery relates to exercise capacity and prognosis in ST- elevation myocardial infarction treated with primary PCI / 中国介入心脏病学杂志

Objective To investigate the relation of post-exercise heart rate recovery(HRR)with exercise capacity, and the predictive value on long-term prognosis in patients of ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). Methods A total of 260 patients were investigated from July 2011 to December 2014. All the patients were conducted cardiopulmonary exercise testing(CPET)within 30 days after STEMI, and heart rate recovery at 1 minute (HRR1)were calculated. The correlation between HRR with exercise tolerance was analysed. The median followup duration was 55 months(42,72), and the cardiovascular endpoint events were collected. Results The mean HRR1 was 26.0±12.2 beats in the whole study population who completed CPET.(1)HRR1 was positively correlated to peak oxygen uptake(VO2peak)(r=0.129, P<0.001).Multiple linear regression analysis demonstrated that VO2peak was independently positively associated with HRR1. (2) Cardiovascular endpoint events occurred in 60 cases (23.1%). Single factor screening through Cox regression model showed that decreased HRR1 (HRR1 ≤ 12 beats)(P=0.010)significantly correlated with the cardiovascular endpoint events. After adjusted by multiple factors, the risk of cardiovascular endpoint events in the group of decreased HRR(HRR1 ≤ 12 beats)was 2.671 times as the group of HRR1>12 beats. Conclusions Decreased HRR1 is associated with lower exercise tolerance, and it shows signifi cant prognostic values in increasing cardiovascular endpoint events in STEMI patients treated with primary PCI.

Hepatocyte growth factor did not enhance the effects of bone marrow-derived mesenchymal stem cells transplantation on cardiac repair in a porcine acute myocardial infarction model / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the impact of combined therapy with transplanting bone marrow-derived mesenchymal stem cells (BM-MSCs) via noninfarct-relative artery and hepatocyte growth factor (HGF) in a porcine myocardial infarction (MI) model.</p><p><b>METHODS</b>BM-MSCs were obtained from pig bone marrow, expanded in vitro with a purity of > 50%. MI was induced by ligating the distal left anterior descending artery in pigs. Eighteen animals received BM-MSCs cells (5 x 10(6)/ml, n = 6), BM-MSCs cells (5 x 10(6)/ml) plus HGF (4 x 10(9) pfu, n = 6) or equal volume culture medium (IMDM) via non-infarct-related artery at four weeks after MI. Gated myocardial perfusion imaging and coronary angiography were performed before and four weeks after transplantations. Histological examination was also performed 4 weeks after transplantation.</p><p><b>RESULTS</b>LVEF measured by gated myocardial perfusion imaging was similar among groups before transplantation and significantly increased in BM-MSCs (45 +/- 3 vs. 34 +/- 2%, P < 0.05) or BM-MSCs + HGF (46 +/- 6 vs. 34 +/- 3%, P < 0.05) treated animals while remained unchanged in IMDM (30 +/- 3 vs. 32 +/- 2%) treated animals 4 weeks post transplantation. Similarly, capillary density was also significantly higher and myocardial perfusion defect scores significantly decreased in BM-MSCs or BM-MSCs + HGF treated hearts than that in IMDM treated hearts. However, all these changes were similar between BM-MSCs and BM-MSCs + HGF groups. Rentrop score was similar before and 4 weeks after transplantation among various groups.</p><p><b>CONCLUSION</b>HGF in combination with BM-MSCs transplantation did not enhance the cardiac repair effects of BM-MSCs transplantation alone and BM-MSCs transplantation did not improve collateral circulation in this model.</p>

Effects of LbGp on the intracellular free calcium concentration of cardiomyocytes induced by hypoxia and KCl / 中国中药杂志

<p><b>OBJECTIVE</b>Hypoxia/KCl injury model in the cultured neonatal rat cardiomyocytes (CMs) was established to investigate the protective effect of Lycium barbanun Glycopeptide (LbGp) on calcium overload.</p><p><b>METHOD</b>Cultured neonatal rat CMs were divided into three groups, namely normal control, hypoxia groups and LbGp-treated group. CMs in LbGp-treated group and hypxia group were cultured in an incubator ventilated with 95% N2 and 5% CO2 with or without LbGP. CMs viability under hypoxia was measured by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide colorimetry (MTT). The intracellular free calcium concentration in cardiomyocytes was measured by laser confocal microscope with Fura-3/AM as a calcium indicator. The protective effects of LbGp on the CMs treated by KCl (60 mmol x L(-1)) was observed.</p><p><b>RESULT</b>As compared with normal controls, the degree of MTT metabolism was significantly reduced (P < 0.01) in hypoxic group and slightly reduced in LbGp (P < 0.05). Hypoxia-induced enhancement of intracellular calcium ([Ca2+]i) was attenuated by LbGp significantly (P < 0.01). Moreover, KCl-induced enhancement of [Ca2+]i was also reduced by LbGp at the doses of 25, 50, 100 microg x mL(-1) in a concentration-dependent manner.</p><p><b>CONCLUSION</b>The result suggested that LbGp is able to increase the survival ratio and inhibit the enhancement of the intracellular free calcium concentration in cardiomyocytes induced by hypoxia and high potassium. One of the mechanisms is that LbGp acts on L-type calcium channels.</p>