Percutaneous intramyocardial stem cell injection in patients with acute myocardial infarction: first-in-man study

Background: Clinical studies on intracoronary stem cell infusion in patients with acute myocardial infarction (AMI) have shown promising results for left ventricular ejection fraction (LVEF). However, preclinical studies have shown that intramyocardial cell injection is better than the intracoronary approach. Objective: To test safety and feasibility of intramyocardial cell injection and left ventricular electromechanical mapping (EMM) early after AMI. Design: On day 10.5 (5) (mean (SD)) after AMI and percutaneous coronary intervention with stent implantation (culprit lesion: 15 LAD, 3 circumflex and 2 right coronary arteries) 20 patients (mean (SD) 60.4 (11.4) years) received bone marrow derived mononuclear cells in the low-voltage area using EMM-guided percutaneous intramyocardial injection. EMM and coronary angiography were performed in 15 patients at 6-months' follow-up. Echocardiography, recording of laboratory data and clinical assessment (6-month and 12-month follow-up) were carried out in all 20 patients. Results: None of the patients showed periprocedural complications. Three patients received an implantable cardioverter-defibrillator for primary prevention of sudden cardiac death and 6 (30%) patients showed in-stent restenosis. One patient underwent bypass surgery owing to chronic stent occlusion after 6 months. 2.0 (0.6) x 10(8) cells, including 1.0 (0.3) x 10(6) CD45(dim)/CD34(hi) stem cells, were injected in each patient. EMM showed a mean (SD) improvement from a baseline unipolar voltage of 45.5 (14.3)% to 59.3 (19.8)% of normal voltage (p=0.002) and reduction of the low-voltage area from 28.7 (12.1)% to 20.3 (13.5)%; (p=0.016). During the 12-month followup, the left ventricular ejection fraction (LVEF) improved from 40.8 (6.9)% to 47.1 (10.6)%; (p=0.037). Conclusion: Left ventricular EMM and percutaneous intramyocardial cell injection in patients with AMI was shown to be a safe procedure. It is associated with improved LVEF and electromechanical parameters after 12-months' follow-up.