***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 
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    Input: Background — Intracoronary transfer of autologous bone marrow cells ( BMC s ) may enhance recovery of left ventricular ( LV ) function in patients after acute myocardial infa rct ion ( AMI ) . However , clinical studies addressing the effects of BMC s after AMI have covered only limited time frames ranging from 3 to 6 months . The critical question of whether BMC transfer can have a sustained impact on LV function remains unanswered . Methods and Results – After percutaneous coronary intervention with stent implantation ( PCI ) of the infa rct -related artery , 60 patients were r and omized 1:1 to a control group with optimal postinfa rct ion therapy and a BMC transfer group that also received an intracoronary BMC infusion 4.8±1.3 days after PCI . Cardiac MRI was performed 3.5±1.5 days , 6±1 months , and 18±6 months after PCI . BMC transfer was not associated with adverse clinical events . In the control group , mean global LV ejection fraction increased by 0.7 and 3.1 percentage points after 6 and 18 months , respectively . LV ejection fraction in the BMC transfer group increased by 6.7 and 5.9 percentage points . The difference in LVEF improvement between groups was significant after 6 months but not after 18 months ( P=0.27 ) . The speed of LV ejection fraction recovery over the course of 18 months was significantly higher in the BMC transfer group ( P=0.001 ) . Conclusions – In this study , a single dose of intracoronary BMC s did not provide long-term benefit on LV systolic function after AMI compared with a r and omized control group ; however , the study suggests an acceleration of LV ejection fraction recovery after AMI by BMC therapy A r and omized controlled study included 44 patients with acute myocardial infa rct ion . It was found that intracoronary injection of bone marrow mononuclear cells is safe , ensures fixation of the injected cells in the myocardium , reduces blood levels of IL-1β and TNF-α , increases the content insulin-like growth factor , and does not provoke malignant arrhythmias Bone marrow mononuclear cells ( BMC s ) from 20 patients with extensive reperfused myocardial infa rct ion ( MI ) were used to assess their myocardial regenerative capability “ in vitro ” and their effect on postinfa rct ion left ventricular ( LV ) remodeling . Human BMC s were labeled , seeded on top of cryoinjured mice heart slices , and cultured . BMC s showed tropism for and ability to graft into the damaged mouse cardiac tissue and , after 1 week , acquired a cardiomyocyte phenotype and expressed cardiac proteins , including connexin43 . In the clinical trial , autologous BMC s ( 78±41 × 106 per patient ) were intracoronarily transplanted 13.5±5.5 days after MI . There were no adverse effects on microvascular function or myocardial injury . No major cardiac events occurred up to 11±5 months . At 6 months , magnetic resonance showed a decrease in the end-systolic volume , improvement of regional and global LV function , and increased thickness of the infa rct ed wall , whereas coronary restenosis was only 15 % . No changes were found in a nonr and omized contemporary control group . Thus , BMC s are capable of nesting into the damaged myocardium and acquire a cardiac cell phenotype in vitro as well as safely benefiting ventricular remodeling in vivo . Large-scale r and omized trials are needed now to assess the clinical efficacy of this treatment BACKGROUND Previous studies have shown improvement in left ventricular function after intracoronary injection of autologous cells derived from bone marrow ( BMC ) in the acute phase of myocardial infa rct ion . We design ed a r and omized , controlled trial to further investigate the effects of this treatment . METHODS Patients with acute ST-elevation myocardial infa rct ion of the anterior wall treated with percutaneous coronary intervention  were r and omly assigned to the group that underwent intracoronary injection of autologous mononuclear BMC or to the control group , in which neither aspiration nor sham injection was performed . Left ventricular function was assessed with the use of electrocardiogram-gated single-photon-emission computed tomography ( SPECT ) and echocardiography at baseline and magnetic resonance imaging ( MRI ) 2 to 3 weeks after the infa rct ion . These procedures were repeated 6 months after the infa rct ion . End points were changes in the left ventricular ejection fraction ( LVEF ) , end-diastolic volume , and infa rct size . RESULTS Of the 50 patients assigned to treatment with mononuclear BMC  , 47 underwent intracoronary injection of the cells at a median of 6 days after myocardial infa rct ion . There were 50 patients in the control group . The mean ( + /-SD ) change in LVEF , measured with the use of SPECT , between baseline and 6 months after infa rct ion for all patients was 7.6+/-10.4 percentage points . The effect of BMC treatment on the change in LVEF was an increase of 0.6 percentage point ( 95 % confidence interval [ CI ] , -3.4 to 4.6 ; P=0.77 ) on SPECT , an increase of 0.6 percentage point ( 95 % CI , -2.6 to 3.8 ; P=0.70 ) on echocardiography , and a decrease of 3.0 percentage points ( 95 % CI , 0.1 to -6.1 ; P=0.054 ) on MRI . The two groups did not differ significantly in changes in left ventricular end-diastolic volume or infa rct size and had similar rates of adverse events . CONCLUSIONS With the methods used , we found no effects of intracoronary injection of autologous mononuclear BMC on global left ventricular function PURPOSE To investigate the effects and safety of autologous peripheral blood stem cell ( PBSCs ) transplantation by intracoronary infusion in patients with acute myocardial infa rct ion ( AMI ) . METHODS 70 patients with AMI were allocated to two groups , one was PBSCs transplantation group ( n=35 ) that received optimal post-infa rct ion medical treatment ( st and ard drug and coronary artery intervention therapy ) and intracoronary transplantation of PBSCs ; the other was control group ( n=35 ) that received optimum post-infa rct ion medical treatment ( st and ard drug and coronary artery intervention therapy ) . The PBSCs transplantation group received granulocyte colony-stimulating factor ( G-CSF : Filgrastim , 300 microg ) with the dose of 300 - 600 microg/day to mobilize the stem cell , and the duration of administration G-CSF was 5 days . On the sixth day , PBSCs were separated by Baxter CS 3000 blood cell separator into suspend liquid 57 ml . Then , the suspend liquid was transferred into the infa rct -related artery ( IRA ) by occluding the over-the-wire balloon and infusing artery through balloon center lumen . In the process of the mobilization , separation and intracoronary infusion of PBSCs , the complications have been investigated . Changes in left ventricular function were assessed at 6-month follow-up . RESULTS 35 cases had finished follow-up in the treated group , while 23 cases in control group . After 6 months , within the treated group , there was a significant improvement in global left ventricular function ejection fraction ( EF ) from a baseline of 50.0+/-8.2 % to 57.1+/-7.8 % ( P<0.0001 ) , wall motion score index ( WMSI ) from 1.219+/-0.190 to 1.101+/-0.118 ( P<0.0001 ) , left end-systolic volume ( ESV ) from 63.8+/-23.9 ml to 52.6+/-20.3 ml ( P=0.01 ) and left end-diastolic volume ( EDV ) from 134.2+/-36.7 ml to 119.2+/-30.3 ml ( P=0.07 ) ; in the control group , there was no significant improvement in EF , WISM , EDV and ESV ( P=0.490 , 0.259 , 0.117 , 0.395 ) . After 6-month follow-up , according to treatment group vs. control group , there was a significant improvement in EF from 57.1+/-7.8 to 52.6+/-5.7 ( P=0.041 ) and WISM from 1.101+/-0.118 to 1.184+/-0.138 ( P=0.034 ) . There were a total of 25 cases with complications during the mobilization , separating and infusion of PBSC . The incidence of complications relating to mobilization was 37.1 % ( 13/35 ) , relating to separating was 14.3 % ( 5/35 ) and relating to intracoronary infusion was 20.0 % ( 7/35 ) . No death was observed . CONCLUSION Autologous PBSCs transplantation by intracoronary infusion is feasible and safe , and it can improve left ventricular function in the 6-month follow-up BACKGROUND Despite the reports on successful treatment of acute myocardial infa rct ion 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 infa rct ion were r and omized 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 infa rct ed 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 99 m sestamibi single photon emission computed tomography . CONCLUSIONS Mononuclear bone marrow cell transplantation improves regional myocardial function of the infa rct ed wall in a dose-dependent manner Objective : To study whether emergent intracoronary autologous bone marrow cell transplantation ( BMT ) is applicable for the treatment of acute myocardial infa rct ion ( AMI ) . Methods : 20 patients admitted within 24 h after the onset of a first AMI were r and omly allocated to receive intracoronary autologous BMT ( n = 10 ) or bone marrow supernatant ( controls , n = 10 ) immediately after primary percutaneous coronary intervention .  Left ventricular ejection fraction ( LVEF ) , left ventricular end diastolic internal diameter ( LVDd ) and myocardial perfusion defect scores were examined respectively by echocardiography and single-photon emission computed tomography at one week and six months after AMI . Results : From one week to six months after AMI , LVEF was enhanced from mean 53.8 ( SD 9.2)% to 58.6 (9.9)% ( p < 0.05 ) in the BMT group but was unchanged in the control group ( 58.2 (7.5)% v 56.3 (3.5)% , p > 0.05 ) ; LVDd remained unchanged ( 52.5 ( 2.8 ) v 52.1 ( 3.2 ) mm , p > 0.05 ) in the BMT group but was significantly enlarged in the control group ( 50.4 ( 6.0 ) v 55.2 ( 7.1 ) mm , p < 0.05 ) . Additionally , myocardial perfusion defect scores decreased from 21 ( 11 ) to 13 ( 10 ) ( p < 0.01 ) in the BMT group but were unchanged in the control group ( 20 ( 14 ) v 17 ( 15 ) , p > 0.05 ) . Conclusion : Emergent intracoronary transplantation of bone marrow mononuclear cells after AMI is practicable , and it improved cardiac function , prevented myocardial remodelling and increased myocardial perfusion at six months ’ follow up BACKGROUND Coronary-stent implantation is frequently performed for treatment of acute myocardial infa rct ion . However , few studies have compared stent implantation with primary angioplasty alone . MET 
    Output:
    
Stem cell treatment for AMI still holds promise .
Clinical ly , these data suggest that improvement over conventional therapy can be achieved .