3.0T Magnetic Resonance Myocardial Perfusion Imaging For Quantitative Evaluation On Coronary Microvascular Dysfunction In Hypertrophic Cardiomyopathy

Objective: To evaluate the coronary microvascular dysfunction in patients with hypertrophic cardiomyopathy(HCM)by MR first-pass perfusion and late gadolinium enhancement.Materials and methods: Retrospectively analyzed 47 patients with HCM(HCM group)and 21 healthy volunteers(control group)from the second affiliated hospital of Nanchang University.HCM group and control group underwent cardiac magnetic resonance(CMR)at rest,including short axial cine,first-pass myocardial perfusion and late gadolinium enhancement scanning.Left ventricular end-diastolic wall thickness(EDTH),end-systolic thickness(ESTH),time to peak(tpeak),maximal upslope of time-intensity curve(slopemax),peak signal intensity(SIpeak),myocardial thickening,and late myocardial gadolinium enhancement(LGE)were assessed for each myocardial segment.The percentage of left ventricular wall thickening was computed from EDTH and ESTH.Control group were set as A/a group.HCM group were divided into LGE segments group(B group)and non-LGE segments group(C group),hypertrophic segments group(b group)and non-hypertrophic segments group(c group).C group were divided into mild,moderate and severe LGE segments subgroup(C1 group,C2 group,C3 group).c group were divided into mild,moderate and severe hypertrophic segments subgroup(c1 group,c2 group,c3 group).The EDTH,myocardial thickening,SIpeak,Slopemax and tpeak in multiple groups were compared by Kruskal-Wallis test.A Spearman correlation test was used to determine the relationships between perfusion parameter,EDTH and LGE.Results: Compared to control group(A group),tpeak increased and Slopemax,SIpeak decreased in non-LGE segments group(B group)and LGE segments group(C group)(p<0.01),while tpeak increased more significantly in C group.The Slopemax and SIpeak has no statistically significant difference between B group and C group(p>0.05).tpeak and SIpeak statistically significantly increased and myocardial thickening statistically significantly decreased with increasing degrees of myocardial LGE(p<0.01).The Slopemax has no statistically significant difference between them(p>0.05).Compared to control group(a group),tpeak increased and Slopemax,SIpeak decreased in non-hypertrophic segments group(b group)and hypertrophic segments group(group)(p<0.01),while tpeak increased more significantly in c group(p=0.023).The Slopemax and SIpeak has no statistically significant difference between b group and c group(p>0.05).tpeak and SIpeak increased and Slopemax decreased with increasing degrees of myocardial hypertrophy,but there was no statistically significant difference between them(p>0.05).EDTH and the degree of LGE were positively correlated with tpeak(r=0.199,p=0.000 and r=0.279,p=0.031,respectively).EDTH were positively correlated with the degree of LGE(r=0.277,p=0.000).EDTH and the degree of LGE and tpeak were negatively correlated with the degree of myocardial thickening(r=-0.669,p=0.000;r=-0.308,p=0.000;r=-0.154,p=0.000,respectively).Conclusion: 3.0T magnetic resonance myocardial perfusion imaging can quantitative evaluate the local coronary microvascular dysfunction in hypertrophic cardiomyopathy.It can show microvascular dysfunction accurately and reliably in non-LGE segments and non-hypertrophic segments.The degree of abnormal perfusion were positively correlated with EDTH and the degree of LGE.Cardiac magnetic resonance can provide basis for risk stratification,therapy planning and treatment of HCM patients.