***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Introduction In large-animal acute myocardial infa rct ion ( AMI ) models , Wharton 's jelly ( umbilical cord matrix ) mesenchymal stem cells ( WJMSCs ) effectively promote angiogenesis and drive functional myocardial regeneration . Human data are lacking . Aim To evaluate the feasibility and safety of a novel myocardial regeneration strategy using human WJMSCs as a unique , allogenic but immuno-privileged , off-the-shelf cellular therapeutic agent . Material and methods The inclusion criterion was first , large ( LVEF ≤ 45 % , CK-MB > 100 U/l ) AMI with successful infa rct -related artery primary percutaneous coronary intervention reperfusion ( TIMI ≥ 2 ) . Ten consecutive patients ( age 32–65 years , peak hs-troponin T 17.3 ±9.1 ng/ml and peak CK-MB 533 ±89 U/l , sustained echo LVEF reduction to 37.6 ±2.6 % , cMRI LVEF 40.3 ±2.7 % and infa rct size 20.1 ±2.8 % ) were enrolled . Results 30 × 106 WJMSCs were administered ( LAD/Cx/RCA in 6/3/1 ) per protocol at ≈ 5–7 days using a cell delivery-dedicated , coronary-non-occlusive method . No clinical symptoms or ECG signs of myocardial ischemia occurred . There was no epicardial flow or myocardial perfusion impairment ( TIMI-3 in all ; cTFC 45 ±8 vs. 44 ±9 , p = 0.51 ) , and no patient showed hs-troponin T elevation ( 0.92 ±0.29 ≤ 24 h before vs. 0.89 ±0.28 ≤ 24 h after ; decrease , p = 0.04 ) . One subject experienced , 2 days after cell transfer , a transient temperature rise ( 38.9 ° C ) ; this was reactive to paracetamol with no sequel . No other adverse events and no significant arrhythmias ( ECG Holter ) occurred . Up to 12 months there was one new , non-index territory lethal AMI but no adverse events that might be attributable to WJMSC treatment . Conclusions This study demonstrated the feasibility and procedural safety of WJMSC use as off-the-shelf cellular therapy in human AMI and suggested further clinical safety of WJMSC cardiac transfer , providing a basis for r and omized placebo-controlled endpoint-powered evaluation Background The use of adult stem cells is limited by the quality and quantity of host stem cells . It has been demonstrated that Wharton ’s jelly – derived mesenchymal stem cells ( WJMSCs ) , a primitive stromal population , could integrate into ischemic cardiac tissues and significantly improve heart function . In this r and omized , controlled trial , our aim was to assess the safety and efficacy of intracoronary WJMSCs in patients with ST-elevation acute myocardial infa rct ion ( AMI ) . Methods In a multicenter trial , 116 patients with acute ST-elevation MI were r and omly assigned to receive an intracoronary infusion of WJMSCs or placebo into the infa rct artery at five to seven days after successful reperfusion therapy . The primary endpoint of safety : the incidence of adverse events ( AEs ) within 18 months , was monitored and quantified . The endpoint of efficacy : the absolute changes in myocardial viability and perfusion of the infa rct ed region from baseline to four months , global left ventricular ejection fraction ( LVEF ) from baseline to 18 months were measured using F-18-fluorodeoxyglucose positron emission computed tomography ( F-18-FDG-PET ) and 99mTc-sestamibi single-photon emission computed tomography ( 99mTc-SPECT ) , and two-dimensional echocardiography , respectively . Results During 18 months follow-up , AEs rates and laboratory tests including tumor , immune , and hematologic indexes were not different between the two groups . The absolute increase in the myocardial viability ( PET ) and perfusion within the infa rct ed territory ( SPECT ) was significantly greater in the WJMSC group [ 6.9 ± 0.6 % ( 95 % CI , 5.7 to 8.2 ) ] and [ 7.1 ± 0.8 % ( 95 % CI , 5.4 to 8.8 ) than in the placebo group [ 3.3 ± 0.7 % ( 95 % CI , 1.8 to 4.7 ) , P < 0.0001 ] and 3.9 ± 0.6(95 % CI , 2.8 to 5.0 ) , P = 0.002 ] at four months . The absolute increase in the LVEF at 18 months in the WJMSC group was significantly greater than that in the placebo group [ 7.8 ± 0.9 ( 6.0 to approximately 9.7 ) vs. 2.8 ± 1.2 ( 0.4 to approximately 5.1 ) , P = 0.001 ] . Concomitantly , the absolute decreases in LV end-systolic volumes and end-diastolic volumes at 18 months in the WJMSC group were significantly greater than those in the placebo group ( P = 0.0004 , P = 0.004 , respectively ) . Conclusions Intracoronary infusion of WJMSCs is safe and effective in patients with AMI , providing clinical ly relevant therapy within a favorable time window . This study encourages additional clinical trials to determine whether WJMSCs may serve as a novel alternative to BMSCs for cardiac stem cell-based therapy . Trial registration Clinical Trials NCT01291329 ( 02/05/2011 ) In experimental studies , mesenchymal stem cell ( MSC ) transplantation in acute myocardial infa rct ion ( AMI ) models has been associated with enhanced neovascularization and myogenesis . Clinical data however , are scarce . Therefore , the present study evaluates the safety and feasibility of intramyocardial MSC injection in nine patients , shortly after AMI during short-term and 5-year follow-up . Periprocedural safety analysis demonstrated one transient ischemic attack . No other adverse events related to MSC treatment were observed during 5-year follow-up . Clinical events were compared to a nonr and omized control group comprising 45 matched controls . A 5-year event-free survival after MSC-treatment was comparable to controls ( 89 vs. 91 % , P = 0.87 ) . Echocardiographic imaging for evaluation of left ventricular function demonstrated improvements up to 5 years after MSC treatment . These findings were not significantly different when compared to controls . The present safety and feasibility study suggest that intramyocardial injection of MSC in patients shortly after AMI is feasible and safe up to 5-year follow-up Recent studies suggest that the intracoronary administration of bone marrow (BM)-derived mesenchymal stem cells ( MSCs ) may improve left ventricular function in patients with acute myocardial infa rct ion ( AMI ) . However , there is still argumentative for the safety and efficacy of MSCs in the AMI setting . We thus performed a r and omized pilot study to investigate the safety and efficacy of MSCs in patients with AMI . Eighty patients with AMI after successful reperfusion therapy were r and omly assigned and received an intracoronary administration of autologous BM-derived MSCs into the infa rct related artery at 1 month . During follow-up period , 58 patients completed the trial . The primary endpoint was changes in left ventricular ejection fraction ( LVEF ) by single-photon emission computed tomography ( SPECT ) at 6 month . We also evaluated treatment-related adverse events . The absolute improvement in the LVEF by SPECT at 6 month was greater in the BM-derived MSCs group than in the control group ( 5.9%±8.5 % vs 1.6%±7.0 % ; P=0.037 ) . There was no treatment-related toxicity during intracoronary administration of MSCs . No significant adverse cardiovascular events occurred during follow-up . In conclusion , the intracoronary infusion of human BM-derived MSCs at 1 month is tolerable and safe with modest improvement in LVEF at 6-month follow-up by SPECT . ( Clinical Trials.gov registration number : NCT01392105 BACKGROUND The study assessed long-term safety and efficacy of intramyocardial injection of autologous bone-marrow derived mesenchymal stromal cells ( BMMSCs ) in patients with severe stable coronary artery disease ( CAD ) and refractory angina . METHODS Thirty-one patients with severe stable CAD and refractory angina were included . Patients had reversible myocardial ischemia and no further revascularization options .  Autologous BMMSCs were isolated , culture exp and ed and stimulated with vascular endothelial growth-factor to facilitate endothelial differentiation . BMMSCs were injected into an ischemic , viable region of the myocardium . Patients were followed for 3 years . RESULTS We found significant clinical improvements in exercise time ( p=0.0016 ) , angina class ( CCS ) ( p<0.0001 ) , weekly number of angina attacks ( p<0.0001 ) and use of nitroglycerine from ( p=0.0017 ) . In the Seattle Angina Question naire there were significant improvements in physical limitation score , angina stability score , angina frequency score and quality of life score ( all p<0.0001 ) . When comparing all hospital admissions from 3 years before to 3 years after treatment , we observed highly reduced admission rates for stable angina ( p<0.0001 ) , revascularization ( p=0.003 ) and overall cardiovascular disease ( p<0.0001 ) . No early or late side-effects of the treatment were observed . CONCLUSIONS The final 3-year follow-up data after intramyocardial injection of autologous BMMSCs , in patients with severe CAD and refractory angina , demonstrated sustained clinical effects , reduced hospital admissions for cardiovascular disease and excellent long-term safety . The results indicate that autotransplantation of BMMSCs to the heart does not only improve symptoms but also slows down disease progression Bone marrow stem cells are able to repair infa rct ed human myocardium following intracoronary transplantation via the infa rct -relative artery . However , traditional reperfusion strategies fail to open the artery in some patients , making effective delivery impossible . Our previous study demonstrated a safe and efficient approach to delivering bone marrow stem cells via a noninfa rct ed artery in an animal myocardial infa rct ion model . The objective of the present study was to evaluate the safety and feasibility of autologous bone marrow mesenchymal stem cell transplantation via such an approach in patients with acute myocardial infa rct ion ( AMI ) . Sixteen patients with anterior AMI who had successfully undergone percutaneous coronary intervention ( PCI ) were enrolled in this pilot , r and omized study . Three weeks after PCI , cultured bone marrow mesenchymal stem cells were injected into the myocardium via either the infa rct -relative artery ( left anterior descending branch artery , LAD ) or a noninfa rct -relative artery ( right coronary artery , RCA ) . The safety and feasibility of the cell infusion were evaluated during the procedure and during 6 months of follow-up . In addition , 2D echocardiography , technetium-99 m methoxyisobutylisonitrile ( 99mTc-MIBI ) and 18F-deoxyglucose single photon emission computed tomography were employed to examine cardiac function , myocardial perfusion , and viable cardiomyocytes , respectively , at day 4 after PCI and 6 months after the cell infusion . There were no arrhythmia and any other side-effects , including infections , allergic reactions or adverse clinical events , during , immediately after , or 6 months after cell transplantation . Cardiac function and myocardial perfusion had improved 6 months after PCI/bone marrow stem cells transplantation . Viable cardiomyocytes metabolism was detected in the infa rct ed areas in both groups after the cell infusion , as demonstrated by 18F-deoxyglucose . Intracoronary infusion of autologous bone marrow mesenchymal stem cells via a noninfa rct -relative artery appears safe and feasible in the treatment of patients with AMI BACKGROUND The infa rct size determines the long-term prognosis of patients with acute myocardial infa rct ion ( AMI ) . There is a growing interest in repairing scar area by transplanting bone marrow stem cells . However , effectiveness of intracoronary injection of bone marrow mesenchymal stem cells ( BMSCs ) in patients with AMI still remains unclear . METHODS Sixty-nine patients with AMI after percutaneous coronary intervention ( PCI )  were r and omly divided into intracoronary injection of BMSCs ( n = 34 ) and saline ( control group , n = 35 ) groups . Serial single positron emission computer tomography ( SPECT ) , cardiac echo and cardiac electromechanical mapping  were done at the design ed time intervals until six months after transplantation of BMSCs or 
    Output:
    
Results from our systematic review suggest that MSC therapy for ischemic heart disease appears to be safe .