Intracoronary delivery of bone marrow cells to the acutely infarcted myocardium. Optimization of the delivery technique.

OBJECTIVES: Intracoronary cell transplantation during catheter balloon inflations may be associated with adverse events. We studied the effectiveness of an alternative transplantation technique--intracoronary cell infusion. METHODS: Fourteen pigs, which had survived acute myocardial infarction, were randomized into 2 treatment groups and 2 controls. Three days after infarction, 12 pigs underwent allogeneic intracoronary mononuclear bone marrow cell transplantation using either the standard technique (short-term cell injections during repeat balloon inflations, technique A, n = 6) or continuous intracoronary cell infusion without balloon inflations (technique B, n = 6). Implanted cells were stained with fluorescent dye. After transplantation, the pigs were euthanized and myocardial samples were analyzed by fluorescent microscopy. RESULTS: The mean numbers of fluorescently labeled bone marrow cells in the infarction border zone, in the infarction mid-area and in the center of myocardial infarction were 84, 72 and 55 using technique A, and 29, 57 and 46 using technique B, respectively. The mean cell retention in the infarction border zone of 84 cells for technique A and 29 cells for technique B differed significantly (p = 0.034, two-tailed t test). CONCLUSION: The continuous intracoronary cell infusion technique is a less efficient cell delivery technique as compared with the standard technique using repeat intracoronary balloon inflations.

Retrospective analysis of coronary interventions in a single centre and comparison of specific differences between radial and femoral access.

Objectives: The aim of this study was to analyse the consequence of radial or femoral access during coronary interventions to radiation dose, fluorography time and a number of pseudoaneurysms following each type of intervention. Background: According to the results of many recent studies (RIVAL, RIFLE-STEACS, STEMI RADIAL), current guidelines favour radial over femoral access during coronary intervention for safety, especially in cases of acute coronary syndromes. However, several papers have referred to problems in the design of these studies and the management of antithrombotic therapy. The influence of access site on radiation dose and fluorography time is also still unclear. Methods: We retrospectively analysed 4522 patients who underwent coronary angiography in 2012 and 2016 in a single centre in the Czech Republic. We compared the access site with the average radiation dose and mean effective dose that each patient received in Gy/cm2 or mSv, respectively. We also compared average fluorography time in minutes and the incidence of pseudoaneurysms. Results: The radiation dose was a body mass index (BMI)-dependent parameter since each five points of body mass index increased radiation dose approximately by 23%. Use of femoral access resulted in lower fluorography time in all subgroups (p < .001) and decreased radiation dose in patients with coronary artery bypass grafts (CABGs) by 26% (p = .044). On the other hand, there has been 16 times lower frequency (p < .001) of post-catheterisation pseudoaneurysms after radial access than after femoral access. Conclusions: Both the radiation dose and fluorography time were lower after femoral access compared to radial access in patients with CABGs. On the other hand, radial access led to significantly fewer periprocedural pseudoaneurysms. Radial access therefore should be considered as the preferred access site during coronary intervention in patients with a high risk of pseudoaneurysm development, and femoral access should be considered for patients with a high risk of contrast-induced nephropathy.

Autologous transplantation of mononuclear bone marrow cells in patients with acute myocardial infarction: the effect of the dose of transplanted cells on myocardial function.

BACKGROUND: Despite the reports on successful treatment of acute myocardial infarction using autologous mononuclear bone marrow cell transplantation, many unresolved questions still remain. We studied the impact of the dose of transplanted cells on myocardial function and perfusion. METHODS: Sixty-six patients with a first acute myocardial infarction were randomized into 3 groups. Two groups were intracoronarily given mononuclear bone marrow cells in either higher (10(8) cells, higher cell dose [HD] group, n = 22) or lower (10(7) cells, lower cell dose [LD] group, n = 22) doses. Twenty-two patients without cell transplantation served as a control (C) group. RESULTS: At 3 months of follow-up, the baseline peak systolic velocities of longitudinal contraction of the infarcted wall of 5.2, 4.5, and 4.3 cm/s in C, LD, and HD groups increased by 0.0, 0.5 (P < .05 vs C group), and 0.9 cm/s (P < .05 vs LD group, P < .01 vs C group), respectively, as demonstrated by Doppler tissue imaging. Baseline left ventricular ejection fractions of 42%, 42%, and 41% in C, LD, and HD groups increased by 2%, 3%, and by 5% (P < .05 vs group C), respectively, as assessed by the gated technetium Tc 99m sestamibi single photon emission computed tomography. CONCLUSIONS: Mononuclear bone marrow cell transplantation improves regional myocardial function of the infarcted wall in a dose-dependent manner.

Serial echocardiographic assessment of the left ventricular function after direct PCI.

BACKGROUND: Acute myocardial infarction (AMI) causes remodelling of the left ventricle (LV). Restoration of patency of an infarct-related artery by percutaneous coronary interventions (PCI) may prevent or inhibit cardiac remodelling. AIM: To assess LV contractility and function by serial echocardiographic examinations. METHODS: The study group consisted of 61 patients (47 males, mean age 60+/-10 years) with acute MI treated with direct PCI. Echocardiography was performed 6-8 days after PCI, and 1, 6 and 12 months thereafter. RESULTS: LV ejection fraction increased significantly at the end of the first month in comparison with the baseline examination whereas EF values obtained after 6 months and after 1 year were not significantly different. Wall motion score index showed a significant improvement after one month, whereas it did not show any further improvement when measured after 6 or 12 months after AMI. The baseline LV end-diastolic diameter was 49+/-6 mm and did not change after one or 6 months, whereas it increased significantly 12 months after AMI. The baseline LV end-systolic diameter was 37+/-5 mm. At the one-month and six-month examinations it was similar to the baseline values but increased significantly to 38+/-6 mm after one year. CONCLUSIONS: These results confirm the beneficial effects of PCI-induced infarct-related artery patency on LV remodelling after AMI.

Experimental model of myocardial infarction: Histopathology and reperfusion damage revisited.

The goal of this pilot study was to create an experimental model of myocardial infarction (for subsequent evaluation of the effectiveness of an alternative way of stem cell application - intracoronary cell infusion in the management of acute myocardial infarction). Four experimental animals, female pigs weighing between 30 and 40 kg, were used in the initial phase of this study to create an experimental model of acute myocardial infarction. An experimental myocardial infarction was performed via occlusion of the interventricular arm of the left coronary artery for 90 min. The hearts were examined 1 h, 3 days, 5 days, and 7 days after the procedure. Macroscopically, red infarction characteristic of reperfusion was found. Microscopically, the healing process with granulation tissue production/collagen deposition was remarkably accelerated compared to literature data. Repair processes in reperfused experimental myocardial infarction and/or reperfused autopsy specimens should not be evaluated on the basis of literature data only. Large collections of extracellular calcium were present. This phenomenon is not well described in the literature and probably has the potential for significantly interfering with the repair process. The histopathology of reperfused acute myoardial infarction deserves to be studied in further investigations.

Three-, 6-, and 12-month results of autologous transplantation of mononuclear bone marrow cells in patients with acute myocardial infarction.

BACKGROUND: There are only few data on long-term effectiveness of the stem cell therapy. AIM: We studied the time course of global and regional left ventricular function in patients with acute myocardial infarction within 1 year after the autologous mononuclear bone marrow cell transplantation. METHODS: Sixty patients with a first acute myocardial infarction, who had been randomized into 3 groups, completed a 12-month protocol. Two groups were intracoronarily given bone marrow cells in either higher (10(8) cells, HD group, n=20) or lower (10(7) cells, LD group, n=20) doses. Twenty patients without cell transplantation served as a control (C) group. Doppler tissue imaging and the gated technetium-99m sestamibi single photon emission computed tomography were performed before cell transplantation and at 3, 6, and 12 months later. RESULTS: The baseline peak systolic velocities of longitudinal contraction of the infarcted wall (S(infarct)) of 5.2 cm/s, 4.6 cm/s, and 4.4 cm/s in C, LD, and HD groups increased by 0.0 cm/s, 0.3 cm/s (p=NS vs. C group), and by 0.7 cm/s (p<0.05 vs. C group), respectively, at 3 months. At 12 months, however, the corresponding changes from baseline values of 0.1 cm/s, 0.2 cm/s, and 0.6 cm/s did not differ significantly (all p=NS). In contrast, the post-transplant improvements in the left ventricular ejection fraction by 6%, 7%, and 7% at months 3, 6, and 12, respectively, were preserved in HD group patients during the whole 12-month follow-up and remained significantly better as compared to controls. CONCLUSIONS: In our study, the autologous mononuclear bone marrow cell transplantation provided sustained improvement in global left ventricular systolic function in patients with acute myocardial infarction. However, when evaluating regional systolic function of the infarcted wall, the short-term benefit was partially lost during the 12-month follow-up.