Evaluation Of Right Ventricular Myocardial Strain Using Cardiac Magnetic Resonance In Coronary Artery Chronic Total Occlusion Patients: A Polit Study

Part 1Assessing Right Ventricular Functions using Cardiac Magnetic Resonance Myocardial Strain in Coronary Artery Chronic Total Occlusion Patients:a Pilot StudyObjective To investigate the quantitative analysis of right ventricle(RV)function in patients with coronary artery chronic total occlusion(CTO)by cardiac magnetic resonance(CMR)myocardial strain(MS)and explore the relationship between RV quantitative indexes and left ventricular ejection fraction(LVEF)as well as left ventricular late gadolinium enhanced(LGE).Materials and methods From January 2015 to December 2018,69 patients(50 male,19 female,mean age62.03±10.66 years old)diagnosed with one or more branch of coronary artery as complete discontinuation of true lumen antegrade coronary blood flow(TIMI flow 0)for a duration more than three months by coronary angiography,all of them underwent enhanced CMR scanning in the first affiliated hospital of dalian medical university.We also enrolled 33 normal volunteers(20 male,13 female,mean age 60.21±7.13 years old)whose gender and age were matched with CTO group.All the subjects were performed on 1.5T MR.All the cardiac parameters were measured by CVI 42 software(cvi42 v5.10,Circle Cardiovascular Imaging,Alberta,Canada),including RV global systolic radial strain(GRS),global systolic radial strain rate(GSRSR),global diastolic radial strain rate(GDRSR),global circumferential strain,(GCS),global systolic circumferential strain rate(GSCSR),global diastolic circumferential strain rate(GDCSR),global longitudinal peak strain(GLS),global systolic longitudinal strain rate(GSLSR),global diastolic longitudinal strain rate(GDLSR)and other left and right ventricular structural and functional parameters.SPSS 22.0 software was used for date analysis.The intra-and inter-group consistency analysis of RV MS measurement were conducted by ICC test.The differences of RV parameters between the CTO group and the normal control group were compared.Independent sample T test was used for normal distribution,while Mann-Whitney U test was used for those non-normal distribution.ANOVA analysis was used to analyze the differences among LVEF?50% group,LVEF< 50% group and normal control group.Pearson correlation analysis was used to analyze the correlation between RV MS parameters and LVEF as well as LGE volumes in CTO patients.P<0.05 was considered statistical significant.Results1.According to the consistency analysis of RV MS parameters in CTO patients,the ICC value for RV MS parameters were all above 0.75 except for the inter-group ICC value of GSLSR(0.672),of which GRS,GCS and GLS had a excellent intra-and inter-group ICC value more than 0.89.2.RV GRS,GCS,GLS,GSRSR,GDRSR,GDCSR and GDLSR all had a significant positive correlation with RVEF(r=0.404,0.370,0.284,0.239,0.439,0.420,0.279 respectively,P < 0.05).3.In terms of RV structural and functional parameters,RVEDV,RVESV,RVSV,RVCO,RVEF and RVM had no significant statistical difference between the CTO group and the normal control group(all P>0.05)except for HR.In terms of RV MS parameters,there was no statistical difference between GRS and GCS,but GLS of CTO group was significantly higher than that of normal control group(-21.23±4.63% vs-15.15±4.23%,P=0.000),and GSRSR,GSCSR,GSLSR,GDRSR,GDCSR and GDLSR also significantly increased in CTO group(all P < 0.01).4.There was no significant difference in RV structural and functional parameters amomg LVEF?50% group,LVEF<50% group and normal control group in CTO patients.For RV MS parameters,there were some significant differences among the three groups except GRS and GCS.When LVEF?50%,GLS,GSRSR,GSCSR,GDRSR and GDCSR were significantly higher than the normal control group(all P<0.05),when LVEF<50%,only GLS and GSLSR were higher than the normal control group.5.For 52 CTO patients with LGE(+),LV LGE volume had no significant correlation with RV structural,functional and MS parameters.Conclusion CMR RV MS can quantitatively analyze the RV myocardial deformation in CTO patients.MS can detect the structural and functional changes of RV earlier than the morphological changes.Regardless of LVEF,CTO patients have compensatory increases in the longitudinal direction of RV MS in the normal range of RVEF.Part 2Assessing Right Ventricular Myocardial Strain after Treatmentusing Cardiac Magnetic Resonance in Coronary Artery Chronic Total Occlusion Patients: a Polit StudyObjective To investigate the quantitative analysis of right ventricular(RV)function in patients with coronary artery chronic total occlusion(CTO)with follow-up after clinical treatment by cardiac magnetic resonance(CMR)myocardial strain(MS).Materials and methods From January 2015 to August 2019,13 male patients(mean age 61.62±11.62 years old)diagnosed with one or more branch of coronary artery as complete discontinuation of true lumen antegrade coronary blood flow(TIMI flow 0)for a duration more than three months by coronary angiography,all of them underwent enhanced CMR scanning before and after treatment in the first affiliated hospital of dalian medical university.10 cases accepted the percutaneous coronary intervention(PCI)stenting,3 cases accepted the conservative medication treatment.CMR reexamination time ranged from 259 to 1168 days(mean time 500.08±228.34 days).All the cardiac parameters were measured by CVI 42 software(cvi42 v5.10,Circle Cardiovascular Imaging,Alberta,Canada)including RV GRS,GSRSR,GDRSR,GCS,GSCSR,GDCSR,GLS,GSLSR,GDLSR and other left and right ventricular structural and functional parameters,including 1eft and right ventricular end-diastolic volume(LVEDV,RVEDV),1eft and right ventricular end-sistolic volume(LVESV,RVESV),1eft and right ventricular stroke volume(LVSV,RVSV),1eft and right ventricular ejection fraction(LVEF,RVEF),1eft and right ventricular cardiac output(LVCO,RVCO),heart rate(HR),1eft and right ventricular mass(LVM,RVM).SPSS 22.0 software was used for date analysis.The differences of LV,RV parameters were compared before and after reexamination.Independent sample T test was used for normal distribution,while Mann-Whitney U test was used for those non-normal distribution.P <0.05 was considered statistical significant.Results1.In terms of LV structural and functional parameters,there was no significant statistical difference in LVEF,LVEDV and LVESV before and after treatment in CTO patients(all P > 0.05).2.In terms of RV parameters,RVEDV and RVESV increased significantly after reexamination(144.52±25.14 vs 118.46±28.08 m L,P=0.02;71.51±14.59 vs55.62±15.93 m L,P=0.014),but RVEF,RV strain and strain rate all had no significant statistical differences.Conclusion After an average of 500.08±228.34 days,CTO patients followed up by CMR show stable RVEF and MS as well as increased RVEDV and RVESV after treatment.