肥厚型心肌病微血管密度与左心室重构的关系

The Relation Between Microvascular Density and Left Ventricular Remodeling in Patients With Hypertrophic Cardiomyopathy

目的:旨在探讨肥厚型心肌病(HCM)微血管密度与左心室重构的关系。方法:对48例HCM患者室间隔标本通过免疫组织化学染色微血管。根据心脏磁共振成像测量左心室重构指数(LVRI)的结果,将患者分为重度重构组(LVRI≥1.3 g/ml,n=25)和轻度重构组(LVRI<1.3 g/ml,n=23),比较两组间微血管密度并分析其对左心室重构的影响;另在轻度室间隔肥厚(<30 mm,n=37)和重度室间隔肥厚(≥30 mm,n=11)患者中,以及高左心室心肌质量指数(LVMI)(男性LVMI≥134 g/m^(2),女性LVMI≥110 g/m^(2),n=15)和低LVMI(男性LVMI<134 g/m^(2),女性LVMI<110 g/m^(2),n=33)患者中,分别进行亚组分析。结果:重度重构组与轻度重构组相比,微血管密度[(398.7±121.3)个/mm^(2) vs.(592.0±239.7)个/mm^(2),P=0.001]、左心室射血分数(LVEF)[(62.3±10.2)%vs.(69.4±8.3)%,P=0.01]明显降低;LVRI[(1.7±0.3)g/ml vs.(1.0±0.1)g/ml,P<0.001]、LVMI[(136.2±36.8)g/m^(2) vs(.82.1±18.2)g/m^(2),P<0.001]、室间隔厚度[(28.5±4.3)mm vs.(22.1±4.3)mm,P<0.001]均明显增高。亚组分析发现,室间隔轻度肥厚患者微血管密度明显高于重度肥厚患者[(524.4±220.5)个/mm^(2) vs.(379.8±117.4)个/mm^(2),P=0.007];低LVMI患者微血管密度也高于高LVMI患者[(517.7±234.0)个/mm^(2) vs.(433.3±131.0)个/mm^(2),P=0.12],尽管差异无统计学意义。相关性分析发现,微血管密度与LVRI(r=-0.32,P=0.026)、LVMI(r=-0.31,P=0.03)及室间隔厚度(r=-0.42,P=0.003)均呈负相关。校正室间隔厚度和LVEF后,多因素Logistic回归分析显示,微血管密度下降(OR=0.990,P=0.03)和LVMI增加(OR=1.10,P=0.03)是HCM进展为重度左心室重构的独立危险因素。结论:发生重度左心室重构的HCM患者微血管密度明显降低、LVMI增加;微血管密度与LVRI、LVMI及室间隔厚度均呈负相关,提示LVMI增加和微血管密度稀疏可能是导致HCM进展为重度左心室重构的危险因素。

Objectives:The aim of present study was to investigate the impact of microvascular density(MVD)on left ventricular(LV)remodeling in patients with hypertrophic cardiomyopathy(HCM).Methods:Microvessels in LV septal wall specimens from 48 HCM patients were stained by immunohistochemical method.According to the results of left ventricular remodeling index(LVRI)measured by cardiovascular magnetic resonance(CMR),HCM patients were divided into severe LV remodeling group(LVRI≥1.3 g/ml,n=25)and mild LV remodeling group(LVRI<1.3 g/ml,n=23).Compared MVD between the 2 groups and analyzed the impact of MVD on LV remodeling.Subgroup analysis was also performed in patients with mild(<30 mm,n=37)and severe septal hypertrophy(≥30 mm,n=11)groups,high left ventricular end-diastolic mass index(LVMI)(LVMI≥134 g/m^(2) in males,LVMI≥110 g/m^(2) in females,n=15)and low LVMI(LVMI<134 g/m^(2) in males,LVMI<110 g/m^(2) in females,n=33)groups.Results:MVD([398.7±121.3]vessels/mm^(2) vs.[592.0±239.7]vessels/mm^(2),P=0.001)and LVEF([62.3±10.2]%vs.[69.4±8.3]%,P=0.01)were significantly lower in the severe LV remodeling group than in mild LV remodeling group.LVRI([1.7±0.3]g/ml vs.[1.0±0.1]g/ml,P<0.001),left ventricular end-diastolic mass index(LVMI)([136.2±36.8]g/m^(2) vs.[82.1±18.2]g/m^(2),P<0.001)and septal thickness([28.5±4.3]mm vs.[22.1±4.3]mm,P<0.001)were significantly higher in the severe LV remodeling group than in mild LV remodeling group.Subgroup analysis showed that MVD was significantly higher in patients with mild septal hypertrophy than that in patients with severe septal hypertrophy([524.4±220.5]vessels/mm^(2) vs.[379.8±117.4]vessels/mm^(2),P=0.007),and MVD was also higher in patients with mild LVMI than that in patients with severe LVMI([517.7±234.0]vessels/mm^(2) vs.[433.3±131.0]vessels/mm^(2),P=0.12).Pearson correlation analysis showed that MVD was negatively correlated with LVMI(r=-0.31,P=0.03),septal thickness(r=-0.42,P=0.003)and LVRI(r=-0.32,P=0.026).Multivariable logistic regression analysis showed that after adjusting for septal thickness and LVEF,reduced MVD(OR=0.990,P=0.03)and increased LVMI(OR=1.10,P=0.03)were independent determinants of severe LV remodeling in HCM patients.Conclusions:MVD is lower and LVMI is higher in HCM patients with severe LV remodeling,MVD is negatively correlated with LVMI,septal thickness and LVRI,our results suggest that reduced MVD and increased LVMI may contribute to severe LV remodeling in HCM patients.