Ischemic mitral regurgitation (IMR) is a common complication after myocardial infarction (MI), following more frequently an inferior MI (38%) rather than anterior ones (10%). Moreover, the management of mild to moderate IMR at the time of coronary artery bypass graft surgery (CABG) is controversial, and its impact on clinical outcomes is still unclear.
In addition to medical therapy and surgical or interventional revascularization strategies, intramyocardial stem cell therapy has become a new therapeutic option for patients with end-stage ischemic heart disease.Moreover, it has been shown that in the chronic post-infarction setting, autologous skeletal myoblast transplantation attenuates mild to moderate chronic ischemic MR, which is otherwise progressive, by decreasing tethering distance over which the leaflets are stretched and improving ejection fraction and wall motion score, thereby enhancing valve coaptation.These promising preclinical results led to several clinical trials evaluating possible benefits of stem cell transplantation in humans. Since apical or posterior displacement of the papillary muscle (PM) in inferior MI results in perturbation of the MV complex and tethering of the MV leaflets, using stem cell therapy would be a practical alternative in mitral regurgitation.
Given the limitations of existing methods for repairing ischemic MR in patients, we are on this supposition that direct intra papillary muscle injection of bone marrow stem cells (BMSCs) in ischemic posteromedial PM in up to moderate IMR in addition to CABG would improve the functional parameters of such patients.
30 patients from Dr.Ghavidel surgery service who meet the inclusion criteria at Rajaee heart center are included in this Phase II clinical trial. All patients are first time candidates for cardiac surgery. They will be randomized into two equal groups with Random number table method of randomization
Treatment: All patients will undergo conventional multivessel CABG (complete revascularization).We will inject 10 times (each0.2 ml per single injection and each 0.5 to 1 X MNC cells per single injection) targeting the infarction border zone. A swab is used to occlude the injection channel for several seconds to minimize reflux of cell suspension. Immediately after the cell injection, de-airing and atrial grafts are done and all proximal grafts will be finalized and the aortic clamp was removed, and the operation was completed as usual.
Control group: All patients will undergo conventional multivessel CABG (complete revascularization)