题目内容：
根据以下材料，回答题 StemCellTherapyMayHelpRepairtheHeart
AccordingtoscientistsintheUSA,stemcelltherapymayonedaybeabletorepairtheheartsofpeoplewithheartfailure．ResearchersatPittsburghUniversitySchoolofMedicineexamined20patientswhohadsevereheartfailureandweregoingtohavesurgery.
Theyinjectedstemcellsintothepartsoftheirheartsthatweredamaged．Theythencomparedtheirheartswiththoseofpeoplewhohadundergonesurgerywithouthavingthestemcellsinjectedintothem(theyhadalsosufferedfromsevereheartfailure)．Thepatientswhohadhadthestemcellsinjectedhadheartsthatwereabletopump(用泵抽运)morebloodthantheothers.
AccordingtoProfessorRobertKormos,oneoftheresearchers,theseresultscouldrevolutionizehearttreatment．Althoughpreviousstudieshadindicatedthattheremightbeabenefit,thisisthefirststudythathasactuallyprovedthatstemcelltherapycanhelpthefailingheartworkbetter.
Allthepatientsinthisstudyhadheartsthatcouldnotpumpbloodproperly．Thescientistsmeasuredtheirejectionfraction(射血分数)．Itisameasureofheartperformance;itmeasureshowmuchbloodisbeingpumpedoutbytheleftventricle(心室).
Healthypeople'sejectionfractionisabout55%．Thesepatientshadejectionfractionofunder35%．Theyallhadby-passsurgery(搭桥手术)performedonthem．Someofthepatientshadstemcellstakenfromtheirhipbonesandinjectedinto25-30sitesinthedamagedheartmuscle．Sixmonthslatertheirejectionfractionratewas46.1%whilethosewhojusthadsurgerybutnostemcellinjectionsaveraged37.2%．Nosideeffectswerereposed.
Heartfailureisacommonproblemallovertheworld．IntheU.K．aloneabout650,000peoplesufferfromheartfailureeveryyear．Asthenumberofpeoplesufferingfromheartfailureincreasesintheworldingeneral,thesefindingsareparticularlysignificant.
Currenttreatmentsrelievethesymptoms．Thisnewstemcelltherapyactuallyrepairsthedamagedmuscleintheheartandhasthepotentialofcuringthedisease.
The20patientshadstemcellinjectionsinsteadofsurgery. A．Right
B．Wrong
C．Notmentioned
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