ObjectiveTo improve and assess the method of establishing myocardial infarction model in New Zealand rabbits. MethodsA total of 60 New Zealand rabbits were randomly divided into two groups:the left anterior descending coronary artery was ligated in a LAD group (n=30); the left circumflex coronary artery was ligated in a LC group (n=30). Electrocardiogram (ECG), ultrasound cardiogram (UCG), hemodynamics and histology procedures were performed to detect the changes of cardiac structure and function after myocardial infarction induced by LAD and LC ligation. ResultsSuccess rate of the LC group was significantly higher than that in the LAD group (P < 0.01), but the survival rate in the LC group was slightly lower than the LAD group (P < 0.05); ECG within 24 h and 1 week after surgery showed that the average values of ST segment elevation in the LC group were significantly higher than that in the LAD group (P < 0.05); UCG and hemodynamics results showed cardiac function in the LAD group did not decrease significantly (P > 0.05). In contrast, cardiac function in the LC group were significantly decreased (P < 0.05). Histopathologic analysis showed that the area of myocardial infarction in the LC group was significantly larger than that in the LAD group (P < 0.01). ConclusionThe myocardial infarction induced by the left circumflex coronary artery ligation is more consistent than that induced by the left anterior descending coronary artery ligation, suggesting that the former is a more appropriate experimental model for evaluations.
Objective To investigate clinical outcomes and perioperative management of off-pump coronary artery bypass grafting （OPCAB） for patients following acute myocardial infarction （AMI）.?Methods?From January 2006 to March 2010， 239 consecutive patients underwent OPCAB on the 14-27 （20.55±3.91） d following AMI（AMI group）in Renji Hospital，School of Medicine of Shanghai Jiaotong University. Preoperative MB isoenzyme of creatine kinase（CK-MB） level was （15.82±6.24） U/L and cardiac troponin I（cTnI） was （0.07±0.04） ng/ml. Clinical data of 406 patients without myocardial infarction history who underwent OPCAB during the same period were also collected as the control group for comparison.?Results?The 30-day mortality of AMI group was 2.51% （6/239）. The causes of death were circulatory failure in 4 patients， ischemic necrosis of lower extremity caused by intra-aortic balloon pump （IABP） in 1 patient and pneumonia with septic shock in 1 patient. Dopamine usage in AMI group was significantly higher than that of the control group （61.51% vs. 37.44%， P=0.001）. Intraoperative or postoperative IABP implantation was more common in AMI group， but there was no statistical difference between the two groups（P＞0.05） . Postoperative drainage and blood transfusion in AMI group were significantly larger than those of the control group （385.18±93.22 ml vs. 316.41±70.05 ml， P=0.022；373.68±69.54 ml vs. 289.78±43.33 ml， P=0.005， respectively）. But there was no statistical difference in re-exploration rate between the two groups （P＞0.05）. There was no statistical difference in the incidence of postoperative new onset atrial fibrillation between the two groups （P＞0.05）. Incidence of acute kidneyinjury of AMI group was significantly higher than that of the control group （13.81% vs. 8.62%， P=0.038）. Postoperative 30-day mortality of AMI group was higher than that of the control group， but there was no statistical difference between the two groups （2.51% vs. 1.48%，P＞0.05）. There was no statistical difference in ICU stay time and postoperative hospital stay between the two groups （2.01±0.95 d vs. 1.78±0.98 d；10.33±4.16 d vs. 9.89±4.52 d， respectively， P＞0.05）. A total of 211 patients （88.28%）in AMI group were followed up for 2.89±1.02 years， and 28 patients （11.72%） were lost during follow-up. Twenty-five patients died during follow-up including 14 cardiac deaths. One-year survival rate was 97.63%， and five-year survival rate was 88.15%.?Conclusion?It’s comparatively safe to perform OPCAB for patients at 2-4 weeks following AMI when their CK-MB and cTnI levels have returned to normal range.
Objective To compare the diagnostic accuracy of different combination regimens of myocardial infarction markers in diagnosing acute myocardial infarction; and to estimate the effect of heart-type fatty acid-binding protein (H-FABP) in improving the diagnostic accuracy of the combinations. Methods Patients with acute onset of chest pain were included randomly. Serum concentrations of H-FABP and other biochemical markers for myocardial infarction (cTnI, Myo) were determined immediately, and then acute myocardial infarction (AMI) patients were defined according to the WHO criteria. ROC curves for three biochemical markers were established respectively, and the cutoff values of the three markers were determined accordingly. Three combination regimens of myocardial infarction markers for AMI diagnosis were designed: cTnI+Myo, cTnI+H-FABP, cTnI+H-FABP+Myo. Diagnostic accuracy of the three regimens were then calculated and compared. Results The AUCs for the three biochemical markers were AUCcTnI 0.938 (95%CI: 0.888-0.988), AUCMyo 0.743 (95%CI: 0.651-0.836), and AUCH-FABP 0.919 (95%CI: 0.873-0.964), respectively. AUCH-FABP was significantly larger than AUCMyo (Plt;0.01). The cutoff values of the three biochemical markers for diagnosing AMI were defined as CutoffcTnI 0.5 ng/mL, CutoffMyo 90 ng/mL, and CutoffH-FABP 5.7 ng/mL, respectively. The diagnostic accuracy of these markers and their combination regimens were calculated and presented as follows (cTnI, Myo, H-FABP, cTnI+Myo, cTnI+H-FABP, cTnI+Myo+H-FABP): sensitivity: 0.804, 0.674, 0.783, 0.957, 0.957 and 0.957; specificity: 0.966, 0.747, 0.954, 0.724, 0.92 and 0.724; diagnostic efficacy: 0.910, 0.722, 0.895, 0.805, 0.932 and 0.805, respectively. Compared with the combination of cTnI+H-FABP, the sensitivities of cTnI (Z=2.261, P=0.024), Myo (Z=3.497, Plt;0.001) and H-FABP (Z=2.478, P=0.013) were significantly lower; the specificities of Myo (Z=3.062, P=0.002), cTnI+Myo (Z=3.378, Plt;0.001) and cTnI+Myo+H-FABP (Z=3.378, Plt;0.001) were significantly lower; and the diagnostic efficacies of Myo (Z=4.528, Plt;0.001), cTnI+Myo (Z=3.064, P=0.002) and cTnI+Myo+H-FABP (Z=3.064, P=0.002) were significantly lower. Conclusion The combination regimen of cTnI+H-FABP which includes H-FABP as the sensitive marker seems to be more effective than the currently used combinations in diagnosing AMI in patients with acute onset of chest pain.
Abstract: Objective To investigate the effect of autologous bone marrow mesenchymal stem cells (MSCs) transplantation on cardiac function and their proliferation and differentiation in the post-infarct myocardium in rabbits. Methods Twenty New Zealand rabbits were randomly divided into two groups, the autologous bone marrow mesenchymal stem cells group (MSCs group,n=10) and control group (n=10). Myocardial infarct model was set up by ligation of the left anterior descending (LAD), two weeks after establishment of the infarct model,either 400μl of cell suspension (total cells 1×106) labled by 1,1’-dioctadecyl3,3,3’,3’-tetramethyl indocarbocyanine perchlorate (Dil) or a comparable volume of L-DMEM medium were autologously transplanted into several different points of the periphery of the scar respectively. To evaluate the heart function, echocardiography were performed before modeling,two weeks after modeling, 2 and 4 weeks after the cells transplantation for asurements of left ventricular end systolic diameter (LVESD) and left ventricular end diastolic diameter (LVEDD), tocalculate left ventricular eject fraction(LVEF) and left ventricular fractional shortening (LVFS). Meanwhile the myocardial contrast echocardiography (MCE) were performed for evaluating the blood perfusion of the post-infarct myocardium. Eight weeks after the transplantation, the animalswere undergoing euthanasia, specimens were acquired for pathology. Results Echocardiography indicated that:The LVEF and LVFS between two groups were fundamentally the same before modeling,two weeks after modeling respectively (0.72±0.08 vs. 0.71±0.04,0.56±0.11 vs. 0.55±0.09; 0.35±0.06 vs. 0.35±0.04, 0.24±0.08 vs. 0.23±0.03, Pgt;0.05), but those were improved significantly in group MSCs when compared with control group at two weeks and four weeks after the cells transplantation(0.71±0.05 vs. 0.60±0.05，0.72±0.07 vs. 0.62±0.08 and 0.34±0.03 vs. 0.29±0.01， 0.35±0.06 vs. 0.27±0.05 respectively,Plt;0.05). There were no differences in LVESD and LVEDD between two groups in any time points(Pgt;0.05). MCE showed the blood perfusion of the infarct myocardium were improved two and four weeks after the cell transplantation. Pathology indicated that Dil positive cells were survived in MSCs transplanted hearts, stained positively for αsarcomeric actin and desmin eight weeks after cell transplantation, HE slides indicated that the capillary density in all the cells transplanted hearts were much higher when compared with control group (38.6±7.6/mm2 vs. 21.4±3.9/mm2，Plt;0.05). ConclusionMSCs can differentiate into cardiomyocytes, improve myocardial perfusion and cardiac function when transplanted into ischemic myocardium.
Objective To identify clinical significance of high level cardiac troponin I （cTnI） in the early postoperative period of off-pump coronary artery bypass grafting （OPCAB） and its predictive value for early clinical outcomes. Methods A total of 240 patients undergoing isolated OPCAB in the Department of Cardiac Surgery of People’s Hospitalof Peking University during 2011 were recruited in the study. There were 164 males and 76 females with their age of 36-83（62.07±8.24） years. Serum cTnI levels in 4-6 hours and 12-18 hours after OPCAB were monitored. Influential factors and its predictive value for early clinical outcomes of OPCAB were analyzed. Binary logistic regression analysis，correlation analysis and receiver operating characteristic （ROC） curve were performed for statistic analysis. Results Serum cTnI level in 4-6 hours after OPCAB （TNI0） was 1.28±0.40 ng/ml，and serum cTnI level in 12-18 hours after OPCAB （TNI1） was 3.60±0.74 ng/ml. Binary logistic regression analysis revealed that graft number was significant influential factors of TNI0 （P=0.000） and TNI1 （P=0.010）. Serum cTnI level in 12-18 hours after OPCAB was significantly correlated with early clinicaloutcomes of OPCAB （P＜0.05），but the correlational relationship was not b （correlation coefficient＜0.5）. ROC curveanalysis showed that serum cTnI level in 12-18 h after OPCAB had higher predictive value for patient prognosis （P＜0.05）. Serum cTnI level higher than 1.49 ng/ml in 12-18 h after OPCAB had good predictive value for postoperative ECG changes，use of intra-aortic balloon pump （IABP） and in-hospital mortality. Conclusions Serum cTnI level increases in varying degrees in the early postoperative period of OPCAB. Together with ECG changes，serum cTnI level can be used for early diagnosis of perioperative myocardial infarction with significant predictive value for early clinical outcomes of OPCAB.
Objective To investigate the effects of granulocyto-colony stimulating factor (G-CSF) on the mobil ization of endothel ial progenitor cells (EPCs) in the rats with myocardial infarction (MI), to observe the density of neovascularization and the mRNA expressions of vascular endothel ial growth factor (VEGF) and its receptor (Flk-1) in the border area of MI. Methods Thirty-six adult male rats (weighing 250-280 g) were divided randomly into control group, MI group, and G-CSF group. In MI group and G-CSF group, the models of MI were establ ished by left anterior descenting coronary artery l igation and were treated with intraperitoneal injection of sal ine (0.3 mL/d) or G-CSF [30 μg/(kg•d)] for 5 days. In control group, after open chest operation, chest was closed without treatment. The level of EPCs was surveyed and the plasma concentrations of VEGF and C-reaction protein (CRP) were measured at 7 days. The mRNA expressions of VEGFand its receptor Flk-1 in the border area of infarct myocardium were determined through RT-PCR. Results Compared withcontrol group, the number of circulating white blood cell (WBC) and EPCs levels, and the serum concentrations of VEGF and CRP were all significantly increased in MI group and G-CSF group (P lt; 0.05); when compared with MI group, the number of circulating WBC and EPCs levels, and the serum concentrations of VEGF were increased and the concentration of CRP was decreased in G-CSF group (P lt; 0.05). Compared with control group, the mRNA expressions of VEGF and Flk-1, and the density of neovascularization in the border area of infarct myocardium were increased in MI group and G-CSF group, whereas those in G-CSF group were significantly augmented compared with MI group (P lt; 0.05). Conclusion In the rats with MI, G-CSF could promote EPCs mobil ization, increase the mRNA expressions of VEGF and Flk-1, and augment the density of neovascularization in the border area of infarct myocardium.
Objective To investigate the extent intravenously transplantation of mesenchymal stem cells (MSCs) mediated by magnetic targeting material arrive in the myocardial infarction region and its effects on the recovery of myocardial infarction. Methods Identify the phenotype of the fourth genet of ex vivo expanded MSCs, stain with DAPI after inducing with 10μmol/L 5-aza, then preserve the MSCs for transplantation. 28 SD rats were divided into three groups: group A (n=10), delivered MSCs combined with magnetic targeting material for 30 minutes to rats through tail vein,and kept on raising after placing magnets on the corresponding skin region to myocardial infarction area for 30min; group B (n=9), administration MSCs not conjuncted with magnetic targeting material through tail vein; group C (n=9), direct intramyocardial transplantation of MSCs. Two days after transplantation, evaluate the aggregation state of MSCs in the area of myocardial infarction; 30d later, estimate the functional and morphological changes in myocardial infarction region. Results We observed that each MSCs had 3-5 molecules of magnetic targeting material attached to its membrane under transmission electron microscope. The homing rates of MSCs respectively were group A 38%, group B 6%, group C 53%.The number of aggregating MSCs of group A and group C was apparently more than that of group B（Plt;0.01）. After transplantation, the contraction indices of left ventricle in group A and group C had significant improvement as compared with that of pretransplantation (LVEF 46%±6% vs. 38%±8%, 51%±5% vs. 35%±4%; LVFS 28%±6% vs. 20%±7%, 32%±4% vs. 20%±5%, Plt;0.05) and administrated cells stained with DAPI could be detected in infarction region under optical microscope. After transplantation, the contraction indices of left ventricle in group B hadn’t conspicuous improvement, and the transplanted cells labeled with DAPI could not be identified in infarction region under optical microscope (homing rate of MSCs 38%). There was no statistically difference of results between group A and group C, but in experiment process, there was a high mortality in group C. Conclusion The method that intravenously delivery of MSCs mediated by magnetic targeting material could accumulate much more MSCs in infarction region, reduce infarction size, and effectively improve the cardiac function after infarction.
Objective To discuss left ventricular reconstruction methods and effectivness in patients with left ventricular aneurysm after myocardial infarction. Methods Between June 2003 and August 2008, 23 patients with left ventricular aneurysm after myocardial infarction were treated. Of them, 13 were male and 10 were female with an average age of 61.2 years (range, 47-74 years). According to New York Heart Association (NYHA) criteria for cardiac function, there were 3 cases of grade I, 6 cases of grade II, 10 cases of grade III, and 4 cases of grade IV. The coronary arteriongraphy showed singlevesseldisease in 2 cases, double-vessel disease in 5 cases, triple-vessel disease in 16 cases. The locations of ventricular aneurysm were the apex cordis in 18 cases, antetheca and parieslateral is in 4 cases, and interior wall in 1 case. The left ventricular ejection fraction was 36.52%± 12.15%, and left ventricular diastol ic final diameter was (62.30 ± 6.52 ) mm. Nine patients received standard l inear repair, 6 patients received standard l inear repair after endocardial ring shrinkage, and 8 patients received patch suture after endocardial ring shinkage. Results Two cases died perioperatively, and re-thoracotomy was performed to stop bleeding in 1 case. Incisions healed by first intention in the other patients without early compl ication. Twentyone patients were followed up 7-48 months (median, 19 months). At 6 months after surgery, the left ventricular ejection fraction 46.52% ± 9.41% were significanly improved when compared with that at preoperation (t=2.240, P=0.023); the left ventricular diastol ic final diameter (52.23 ± 5.11) mm were significantly decreased when compared with that at preoperation (t=2.170, P=0.035). The cardiac function according to NYHA criteria was at grade I in 8 cases and at grade II in 13 cases. One patient died of cerebral hemorrhage at 18 months after operation and the activities of daily l iving recoverd in the others. Conclusion Individual theraputic methods are used according to patients’ different conditions for left ventricular aneurysm after myocardial infarction.
Objective To summarize the surgical experiences of ventricular septal rupture (VSR) after acute myocardial infarction (AMI) and investigate the time and methods of surgery. Methods From January 1999 to December 2008, 22 patients with VSR after AMI underwent surgical procedures. There were 17 male and 5 female with a age of 3978 years (mean age of 61.77 years). There were 18 cases with anterior VSR and 4 cases with posterior VSR, all of them combined with left ventricular aneurysm. Twentytwo cases underwent ventricular septal repair and aneurysm resection, 16 cases underwent coronary artery bypass grafting concomitantly with a graft of 2.11±1.57. Results There were 2 perioperative deaths (9.09%), 1 died of severe low cardiac output syndrome and 1 died of massive cerebral embolism. The other 20 cases were all cured and discharged. According to cardiac function classification from New York Heart Association（NYHA）, there were 4 cases in grade Ⅲ, 12 cases in grade Ⅱ and 4 cases in grade Ⅰ. Echocardiography showed that there were no VSR shunt and 2 cases with mild mitral valve regurgitation. Postoperative left ventricular enddiastolic diameter (LVEDD) reduced significantly compared with that before operation (50.27±5.33 mm vs. 57.94±6.79 mm, t=4.437, P=0.000). Sixteen cases were followed up, and the follow-up time was 3.24 months (13.9±6.5 months). Four cases were lost. There was no late death and cardiovascular event during following up. There were 11 cases in cardiac function classification (NYHA) grade Ⅱ and 5 in grade Ⅰ. Echocardiography showed that LVEDD reduced significantly (49.50±4.66 mm vs. 57.94±6.79 mm, t=5.041, P=0.000) and left ventricular ejection fraction (LVEF) increased significantly (55.08%±6.72% vs. 45.57%±11.31%, t=2.719, P=0.013)compared with those before operation. Conclusion VSR after AMI is one of the serious complications of AMI. Proper operation timing, perfect preoperative preparation, appropriate perioperative treatment, right surgical method and the avoidance of complications can effectively reduce the mortality and improve the prognosis.
Objective To investigate the clinical characteristics of acute myocardial infarction ( AMI) in elderly patients with acute exacerbation of chronic obstructive pulmonary disease ( AECOPD) .Methods Clinical data of 16 elderly patients with AECOPD and AMI from may 2007 to December 2009 were reviewed. Meanwhile, 128 elderly AECOPD patients without AMI were analyzed as control. Results Neither the AMI group nor the control group had typical precordial pain, conscious disturbance, andhypotension. Compared with the control group, the main symptoms of the AMI group were worsening of chest tightness and dyspnea( 16 /16 vs. 4/128, P lt;0. 01) ,most of which accompanying fever( 11/16 vs. 6/128, P lt;0. 05) and anorexia ( 10/16 vs. 23 /128, P lt; 0. 05) . The incidence of patches-like shadow on chest X-rayincreased ( 16 /16 vs. 62/128, P lt;0. 05) , PaO2 ( mm Hg) decreased ( 43. 72 ±3. 64 vs. 82. 26 ±11. 41, P lt;0. 001) , the red blood cell count ( ×1012 /L) increased ( 6. 43 ±0. 42 vs. 4. 11 ±1. 24, P lt; 0. 05) , the concentration of total cholesterol ( mmol /L) increased ( 6. 51 ±0. 84 vs. 3. 93 ±1. 14, P lt; 0. 05) , the needfor invasive mechanical ventilation increased ( 13/16 vs. 11 /128, P lt; 0. 05) , the days in hospital were prolonged ( 35 ±13 vs. 11 ±3, P lt; 0. 01) , the cost ( 1000 RMB) increased( 32 ±11 vs. 7. 6 ±2. 8, P lt;0. 01) , and the mortality also increased ( 2/16 vs. 3 /128, P lt;0. 01) . Conclusion AMI should be alerted in the case of sudden exacerbation of chest tightness and dyspnea in elderly patients with AECOPD.