Safety of intramyocardial injection of autologous bone marrow cells to treat myocardial ischemia in pigs

OBJECTIVE: The purpose of this study is to determine the potential adverse consequences of intracardiac injections of bone marrow mononuclear cells (BMCs) to facilitate the revascularization of ischemic myocardium. BACKGROUND: Bone marrow mononuclear cells are used to treat heart failure, though there are few studies that evaluated the safety of BMC transplantation for chronic myocardial ischemia. METHODS: The pigs received coronary ameroid constrictors to induce chronic myocardial ischemia and left ventricular dysfunction. At 4 weeks, autologous BMCs were injected intramyocardially by Boston Scientific Stiletto catheter with low-dose (10(7) cells) or high-dose BMC (10(8)). Control animals received saline. Blood samples were collected for hematological and chemical indices, including cardiac enzyme levels at regular time intervals postinfarction. At 7 weeks, animals underwent electrophysiological study to evaluate the arrhythmic potential of transplanted BMC, followed by necropsy and histopathology. RESULTS: No mortalities were associated with intramyocardial delivery of BMC or saline. At Day 0, the total creatine phosphokinase (CPK) was in the normal range in all groups. All groups had significant elevations in CPK after ameroid placement, with no significant differences between groups. At 7 weeks, CPK in all groups had returned to pretreatment levels. Electrophysiological assessment revealed that one control animal had an inducible arrhythmia. No arrhythmias were induced in low- or high-dose BMC-treated pigs. There were no histopathological changes associated with BMC injection. CONCLUSION: This study showed, in a clinically relevant large-animal model, that catheter-based intramyocardial injection of autologous BMC into ischemic myocardium is safe.     

Multislice MR perfusion imaging and regional myocardial function analysis: complimentary findings in chronic myocardial ischemia

Purpose: The purpose of this study is to assess the reliability of multislice MR perfusion imaging in comparison to regional wall function and nuclear medicine and to test different qualitative and quantitative parameters for perfusion assessment. Material and methods: 15 patients with chronic myocardial ischemia underwent CINE and first-pass perfusion MR imaging. Functional myocardial imaging was performed using a segmented CINE FLASH sequence and systolic myocardial wall thickening was assessed after semiautomated segmentation. MR first-pass perfusion studies were performed using a multislice saturation recovery TurboFLASH sequence. Different parameters were calculated for assessment of hypoperfused segments and results of MR imaging compared to ^99mTc-SestaMIBI SPECT. Results: MR perfusion imaging showed a sensitivity of 72% and a specificity of 98%. In combination with MR CINE imaging and wall thickening analysis we calculated a sensitivity of 100% and a specificity of 93%. Qualitative and quantitative perfusion parameter analysis showed significant differences between normal and hypoperfused segments for the signal intensity increase (p < 0.001), the signal intensity upslope (p < 0.001) as well as for the myocardial mean transit time (p < 0.001). Conclusion: The combination of systolic wall thickening analysis and myocardial perfusion can markedly improve the sensitivity of MRI in depiction of LV myocardial perfusion abnormalities. For assessment of hypoperfusion, different quantitative and qualitative parameters can be calculated showing significant differences between normal state and hypoperfusion.     

Selective pressure-regulated retroinfusion of fibroblast growth factor-2 into the coronary vein enhances regional myocardial blood flow and function in pigs with chronic myocardial ischemia

OBJECTIVES: We sought to improve regional myocardial delivery and subsequent collateral perfusion induced by basic fibroblast growth factor-2 (FGF-2) using selective pressure-regulated retroinfusion of coronary veins for delivery. This hypothesis was tested in a newly developed pig model with percutaneous induction of chronic ischemia. BACKGROUND: Selective pressure-regulated retroinfusion of coronary veins is a catheter-based procedure that has been shown to provide effective regional delivery of drugs and gene vectors into ischemic myocardium. METHODS: A high-grade stenosis with subsequent progression to total occlusion within 28 days was induced by implanting a reduction stent graft into the left anterior descending artery (LAD). After seven days, a 30-min retroinfusion (anterior cardiac vein) was performed with (n = 7) or without (n = 7) 150 microg FGF-2 and compared with a 30-min antegrade infusion of 150 microg FGF-2 into the LAD (n = 7). Sonomicrometry to assess regional myocardial function at rest and during pacing, and microspheres to assess regional myocardial blood flow, were performed 28 days after implantation of the reduction stent. RESULTS: Retroinfusion of FGF-2 compared favorably with controls and with antegrade infusion of FGF-2 with regard to regional myocardial function at rest (18.5 +/- 4.1% vs. 5.7 +/- 2.9% vs. 7.9 +/- 1.8%, respectively, p < 0.05) and during pacing. Regional myocardial blood flow was also higher in the LAD territory after retroinfusion of FGF-2 (1.07 +/- 0.14 vs. 0.66 +/- 0.07 vs. 0.72 +/- 0.17 ml x min(-1) x g(-1), p < 0.05). CONCLUSIONS: Selective pressure-regulated retroinfusion increased tissue binding of FGF-2 and enhanced functionally relevant collateral perfusion compared with antegrade intracoronary delivery in pigs with chronic myocardial ischemia.     

陈旧性前壁心肌梗死患者自体骨髓单个核细胞移植后左室心肌灌注及收缩功能的变化

目的　评价经冠状动脉内自体骨髓单个核细胞移植对陈旧性心肌梗死患者心功能和心肌灌注的影响及其安全性。方法与结果　入选 10例陈旧性前壁心肌梗死患者 ,在冠状动脉造影和介入治疗后 ,经冠状动脉内灌注导管将自体骨髓单个核细胞缓慢注入前降支。随访 3个月后 ,左室射血分数由术前 4 5 3%± 9 8%升高至 5 4 5 %± 6 5 % (P =0 0 0 3) ;2 0 1 Tl心肌灌注显像 (SPECT)显示左心室心肌灌注明显改善 ,即刻和延迟心肌灌注评分分别由术前的 2 9 5± 5 8和 2 8 6± 6 3降低至 2 3 9±5 7和 2 3 0± 6 1(P均 <0 0 1) ,没有手术有关的并发症和恶性心律失常发生。结论　陈旧性前壁心肌梗死患者经冠状动脉内自体骨髓单个核细胞移植 ,可显著改善左室收缩功能和心肌灌注 ,并且具有良好的临床操作安全性。     

冠状动脉内自体骨髓单个核细胞移植治疗急性心肌梗死患者的疗效

目的:探讨急性心肌梗死患者自体骨髓单个核细胞经冠状动脉移植的安全性和对心功能的保护作用。方法:2003年3月以来,84例急性心肌梗死患者急诊静脉溶栓或急诊经皮冠状动脉成形术(PTCA)加支架治疗后2周内行择期冠状动脉造影或PTCA加支架治疗,其中50例抽取骨髓40ml,提取单个核细胞,经冠状动脉注入,另34例不做自体骨髓单个核细胞经冠状动脉移植,作为对照组。81例患者术前和术后6个月、2年均行多巴酚丁胺负荷试验(另3例未完成超声心动图随访观察)。结果:治疗组患者临床随访无明显不良反应,心功能明显改善,运动耐量增加。多巴酚丁胺负荷试验左室射血分数(LVEF)和室壁运动记分指数(WMSI)显著改善,峰值LVEF和WMSI与基础状态LVEF和WMSI的差值在治疗前后相比,与对照组相比均差异有统计学意义。结论:自体骨髓单个核细胞经冠状动脉移植治疗急性心肌梗死患者,经6个月～2年的临床观察无明显不良反应,具备安全性,多巴酚丁胺负荷试验显示出自体骨髓单个核细胞治疗对梗死后心功能有保护作用。     

冠状动脉内自体骨髓单个核细胞移植治疗急性心肌梗死患者的长期疗效观察

目的:探讨急性心肌梗死患者自体骨髓单个核细胞(BM-MNCs)经冠状动脉移植治疗对心功能的长期保护作用.方法:84例急性心肌梗死患者,急诊静脉溶栓或急诊介入治疗[经皮冠状动脉成形术(PTCA)加支架置入]后2周内行择期介入治疗.84例中50例作为细胞治疗组,抽取骨髓40 ml, 提取BM-MNCs,经冠状动脉注入;另34例作为对照组以同样方法注入20 ml的0.9%氯化钠溶液.所有患者均于发病1～2周(平均9.5 d)时(择期介入前)进行超声心动图检查和低剂量多巴酚丁胺超声心动图负荷试验,于发病6个月和1～5年时复查;并随访记录心血管事件发生率及病死率.结果:细胞治疗组患者5年临床随访心血管事件发生率及病死率均明显低于对照组,且心功能改善更加明显; 6个月复查时,2组患者左室射血分数(LVEF)和室壁运动记分指数(WMSI)、左室舒张末容积指数(EDVI)、左室收缩末容积指数(ESVI)、心排血指数(CI)、每搏量指数(SI)等心功能指标均较术前有明显改善(P<0.01),但细胞治疗组WMSI、LVEF、ESVI、CI等指标及负荷状态下WMSI(△WMSI)、LVEF(△LVEF)均较对照组改善得更明显(P<0.01);5年超声心动图复查时,细胞治疗组EDVI、CI及LVEF较术前明显改善(P<0.01),并明显优于对照组(P<0.01).结论:自体BM-MNCs治疗对梗死后心功能有长期保护作用.     

Intracoronary basic fibroblast growth factor enhances myocardial collateral perfusion in dogs

OBJECTIVE: In preparation for clinical trials of basic fibroblast growth factor (bFGF) to treat ischemic heart disease, we sought to identify a clinically feasible method of bFGF administration. BACKGROUND: Basic FGF has been shown to promote collateral development after experimentally induced coronary occlusion; however, methods of bFGF delivery that have been shown to be effective in previous investigations would not be practical for clinical use. METHODS: Four randomized, blinded, controlled investigations were conducted independently and sequentially in an established canine model. For all studies, dogs underwent operative placement of proximal left circumflex coronary artery ameroid constrictors. The four investigational regimens included: 1) bFGF by central venous bolus injection, 1,740 microg/day for one, two or seven days; 2) bFGF by intravenous infusion, 100 microg/kg body weight per day for seven days; 3) bFGF by pericardial instillation, 2,000 microg/day for 7 days; and 4) bFGF by intracoronary injection (Judkin's technique), 100 microg/kg per day for one or two days. Each substudy included a contemporaneous vehicle control group. Collateral perfusion (microspheres) was assessed during maximal coronary vasodilation during the first month after ameroid placement. RESULTS: Maximal collateral perfusion in dogs that received intracoronary bFGF for two days exceeded that of concurrent control dogs by 31% (p < 0.01). Perfusion was not increased in dogs that received single-dose intracoronary bFGF. Basic FGF administration by central venous bolus injection, intravenous infusion and pericardial injection failed to enhance collateral perfusion. CONCLUSIONS: Administration of bFGF by the intracoronary route, an intervention that is feasible in patients, augments collateral development in dogs. These data provide a rationale for clinical testing of intracoronary bFGF in ischemic heart disease.     

Hypocellularity and insufficient expression of angiogenic factors in implanted autologous bone marrow in patients with chronic critical limb ischemia

The aim of this study was to identify the clinical parameters of absolutely poor-prognosis patients with chronic critical limb ischemia (AP-CLI). Sixteen no-option CLI patients with arteriosclerosis obliterans: ASO (nine) and non-ASO patients (seven) treated with bone marrow-mononuclear cell implantation (BMI) were analyzed. There were three AP-CLI patients (all ASO). The mRNA expression of several angiogenic factors in the implanted cells was analyzed in comparison with normal donor bone marrow. To observe the response of bone marrow components to hypoxia, normal bone marrow cells were cultured for 24?h in 2.5% O₂, and mRNA expression of angiogenic factors were measured. AP-CLI patients exhibited extraordinary low bone marrow cellularity as well as the percentage of CD34-positive cells. Among angiogenic factors, only VEGF expression was maintained in response to HIF-1, while other factors such as HGF, Ang-1, PLGF, and SDF-1 decreased in the implanted bone marrow cells of the patients with CLI compared to normal bone marrow cells. HIF-1 and all of the five angiogenic factors increased in vitro in response to hypoxia. Thus it is highly likely that angiogenic factors except VEGF do not respond to chronic ischemia in bone marrow in vivo. An organ-protection system against tissue ischemia may be applied for acute hypoxia, but it may be insufficient for chronic ischemia.     

Feasibility and safety of regional myocardial hypothermia during myocardial ischemia and infarction in pigs

OBJECTIVE: Mild systemic hypothermia has been shown to be feasible and safe in patients during acute myocardial infarction (AMI). Regional myocardial hypothermia of the ischemic myocardium only may be more effective in myocardial salvage with fewer side effects compared with systemic hypothermia. The purpose of this study was to evaluate the feasibility and safety of regional myocardial hypothermia in pigs. METHODS: Open-chest pigs with (n=5) or without (n=4) myocardial infarction underwent left anterior descending coronary artery (LAD) ligation followed by intracoronary infusion of lactated Ringer's solution (at room temperature and at 15 degrees C between 20-35 ml/min for 3 min) via the central lumen of a specially designed balloon catheter at the time of reperfusion. Intramyocardial temperatures via thermocouples at the ischemic zone (LAD territory) and non-ischemic zone (circumflex territory) as well as systemic temperature were constantly recorded, as were the hemodynamics. Each pig acted as its control regarding the myocardial temperature response to both solutions. In addition, intracoronary versus intramyocardial temperatures were compared with thermocouples in both territories during infusion. RESULTS: There was no hemodynamic compromise or arrhythmia seen during the intracoronary infusion of either temperature solution. There was a linear relationship between the infusion solution temperature and infusion rate versus intramyocardial temperature response, with the cooled solution providing 2 degrees C lower temperature and faster infusion resulting in lower intramyocardial temperature. There was no change in the non-ischemic zone or systemic temperature. On average, 6-8 degrees C reduction in tissue temperature, potential target temperature range for hypothermic therapy, was achieved in all animals. In addition, intracoronary temperature in distal LAD measured by intracoronary thermocouples correlated with the intramyocardial temperature (2 degrees C lower temperature in the coronary artery). CONCLUSION: It is feasible and safe to achieve regional myocardial hypothermia by intracoronary infusion of cooled solution in pigs.     

Intramyocardial bone marrow cell transplantation and the progression of coronary atherosclerosis in patients with chronic myocardial ischemia

BACKGROUND: Cell therapy has been proposed as a novel treatment strategy for patients with ischemic heart disease. However, two recent studies suggested that cardiac cell transplantation might aggravate coronary atherosclerosis. The aim of the current study was to assess whether intramyocardial bone marrow cell transplantation in patients with chronic myocardial ischemia is associated with progression of coronary atherosclerosis. METHODS: In 30 patients with chronic ischemia, bone marrow was aspirated from the iliac crest. During mononuclear cell isolation, coronary angiography was performed. Thereafter, 94+/-18 x 10(6) cells were injected intramyocardially (NOGA system) in regions with ischemia on technetium-99m tetrofosmin SPECT. RESULTS: During the 12-month follow-up period, there was no clinical evidence of progression of atherosclerosis. CCS class improved from 3.4+/-0.5 to 2.4+/-0.8 at 3 months, 2.4+/-0.9 at 6 months and 2.5+/-0.9 at 12 months (P<0.01). MRI-determined left ventricular ejection fraction increased from 51+/-12% to 54+/-12% at 3 months (P<0.01) and the number of ischemic segments per patient on SPECT decreased from 5.2+/-2.6 to 2.1+/-2.2 at 3 months (P<0.01). Repeat coronary angiography at 4 months revealed that bone marrow cell transplantation did not decrease minimal luminal diameter (1.81+/-0.80 mm versus 1.79+/-0.82 mm, P = NS) or mean luminal diameter (2.48+/-0.85 mm versus 2.46+/-0.86 mm, P = NS). Similarly, the percentage diameter stenosis (32+/-19% versus 32+/-20%, P = NS) and the atheromatosis severity score (4.78+/-2.40 versus 4.80+/-2.40, P = NS) remained unchanged. CONCLUSION: Intramyocardial bone marrow cell transplantation in patients with chronic myocardial ischemia was not associated with significant progression of atherosclerosis.     

Intramyocardial bone marrow cell transplantation and the progression of coronary atherosclerosis in patients with chronic myocardial ischemia

Background: Cell therapy has been proposed as a novel treatment strategy for patients with ischemic heart disease. However, two recent studies suggested that cardiac cell transplantation might aggravate coronary atherosclerosis. The aim of the current study was to assess whether intramyocardial bone marrow cell transplantation in patients with chronic myocardial ischemia is associated with progression of coronary atherosclerosis. Methods: In 30 patients with chronic ischemia, bone marrow was aspirated from the iliac crest. During mononuclear cell isolation, coronary angiography was performed. Thereafter, 94±18x10⁶ cells were injected intramyocardially (NOGA system) in regions with ischemia on technetium‐99m tetrofosmin SPECT. Results: During the 12‐month follow‐up period, there was no clinical evidence of progression of atherosclerosis. CCS class improved from 3.4±0.5 to 2.4±0.8 at 3 months, 2.4±0.9 at 6 months and 2.5±0.9 at 12 months (P<0.01). MRI‐determined left ventricular ejection fraction increased from 51±12% to 54±12% at 3 months (P<0.01) and the number of ischemic segments per patient on SPECT decreased from 5.2±2.6 to 2.1±2.2 at 3 months (P<0.01). Repeat coronary angiography at 4 months revealed that bone marrow cell transplantation did not decrease minimal luminal diameter (1.81±0.80?mm versus 1.79±0.82?mm, P = NS) or mean luminal diameter (2.48±0.85?mm versus 2.46±0.86?mm, P = NS). Similarly, the percentage diameter stenosis (32±19% versus 32±20%, P = NS) and the atheromatosis severity score (4.78±2.40 versus 4.80±2.40, P = NS) remained unchanged. Conclusion: Intramyocardial bone marrow cell transplantation in patients with chronic myocardial ischemia was not associated with significant progression of atherosclerosis.     

Effect of regional myocardial perfusion abnormalities on regional myocardial early diastolic function in patients with hypertrophic cardiomyopathy

Summary Nonuniform hypertrophy of the left ventricle is an important factor in regional diastolic dysfunction in patients with hypertrophic cardiomyopathy (HCM). However, the effect of myocardial perfusion abnormalities on regional diastolic dysfunction has not been established in patients with HCM. We investigated the relationship between regional myocardial perfusion abnormalities and regional early diastolic function in 31 patients with HCM and 8 control patients. Short-axis images of the left ventricle recorded by cine magnetic resonance imaging were divided into ten blocks. The time-to-peak-wall-thickness-thinning rate (TPWR) and the wall thickness were measured in each block. Of the 310 blocks from the patients with HCM, 242 (78%) showed normal thallium-201 uptake (group 1), 40 (13%) showed slightly decreased uptake (group 2), and 28 (9%) showed markedly decreased uptake (group 3). There was no difference in the regional wall thickness among the three groups. The TPWR was longer in patients with HCM than in control patients. It was significantly longer in group 3 (190±45ms) than in group 1 (167±36ms) and group 2 (160±31ms). (P<0.01). The linear regression slope of the relationship between the TPWR and the regional wall thickness was significantly steeper in group 3 than in groups 1 and 2 (P<0.05). In conclusion, abnormalities in regional myocardial perfusion, in addition to regional hypertrophy, contributed to the regional early diastolic dysfunction in patients with HCM.