肥厚型心肌病患者心肌纤维化范围的相关因素分析

目的探讨肥厚型心肌病患者心肌纤维化范围的相关因素。方法该研究为横断面分析性研究,入选2016年1月至2020年5月在云南省第一人民医院住院的肥厚型心肌病患者。通过病案管理系统收集入选患者的一般临床资料。入选者均行心脏磁共振(CMR)检查,以CMR钆对比剂延迟强化(LGE)识别是否存在心肌纤维化及其部位,应用视觉分析法计算LGE范围(LGE%)。根据是否存在LGE分为LGE阳性组和LGE阴性组,进一步根据左心室舒张末期最大室壁厚度(LVMWT)将LGE阳性组患者分为轻度肥厚组、中度肥厚组和重度肥厚组。入选患者均测定外周血N末端B型利钠肽原(NT-proBNP)和心肌肌钙蛋白I(cTnI)水平。结果该研究共入选患者48例,年龄(46.4±14.3)岁,其中男性42例(87.5%)。CMR检查示LGE阳性患者34例(LGE阳性组)占70.8%,阴性者14例(LGE阴性组)。与LGE阴性组比较,LGE阳性组患者较为年轻(P=0.038),纽约心脏协会心功能Ⅲ/Ⅳ级者占比较高(P=0.00)。与LGE阴性组比较,LGE阳性组患者LVMWT较厚(P=0.008),左心室质量指数(LVMI)较大(P=0.001),左心室舒张末期容积(LVEDV)较大(P=0.043),左心室射血分数(LVEF)和心脏指数(CI)均较低(P均<0.05)。LGE阳性组患者血NT-proBNP和cTnI水平均明显高于LGE阴性组[分别为2760.5(1503.4,3783.6)ng/L比861.3(552.2,1092.8)ng/L,P=0.002;0.970(0.448,1.684)μg/L比0.147(0.033,0.251)μg/L,P=0.041]。LGE阳性组患者心肌轻度肥厚者15例(轻度肥厚组)、中度肥厚者10例(中度肥厚组)、重度肥厚者9例(重度肥厚组),3个亚组间LGE%以及NT-proBNP和cTNI均随着心肌肥厚程度增加而增加(P均<0.05)。LGE%与年龄呈负相关性(r=-0.618,P=0.011),与NT-proBNP、cTnI水平呈正相关(分别为,r=0.271,P=0.010;r=0.111,P=0.013),与LVEDV、LVMWT及LVMI均呈正相关(分别为,r=0.438,P=0.09;r=0.735,P=0.001;r=0.532,P=0.034)。结论肥厚型心肌病患者心肌纤维化范围与年龄呈负相关,与血NT-proBNP、cTnI水平以及LVEDV、LVMWT、LVMI均呈正相关。

Analysis on related factors of myocardial fibrosis in patients with hypertrophic cardiomyopathy

Objective To investigate the related factors of myocardial fibrosis in patients with hypertrophic cardiomyopathy.Methods Patients with hypertrophic cardiomyopathy,hospitalized in the First People's Hospital of Yunnan Province from January 2016 to May 2020,were included in this cross-sectional study.Patients were divided into delayed enhancement positive group(fibrosis group)and non-delayed enhancement group(non-fibrosis group).According to the maximum left ventricular end diastolic wall thickness(LVMWT),patients in the fibrosis group was further divided into mild hypertrophy group,moderate hypertrophy group and severe hypertrophy group.The baseline clinical data of patients were collected by medical record management system.All enrolled patients underwent cardiac magnetic resonance imaging(CMR).The presence and location of myocardial fibrosis were identified by CMR gadolinium contrast delayed enhancement(LGE).The range of LGE(LGE%)was calculated by visual analysis.The levels of N-terminal pro-B-type natriuretic peptide(NT-proBNP)and cardiac troponin I(cTnI)in peripheral blood were measured.Results A total of 48 patients(age(46.4±14.3)years,42(87.5%)males)were enrolled.There were 34 LGE positive cases(fibrosis group)and 14 LGE negative cases(non-fibrosis group).Compared with non-fibrosis group,patients in fibrosis group were younger(P=0.038)and prevalence of NYHA gradeⅢ/Ⅳwas higher(P=0.00).Compared with non-fibrosis group,patients in fibrosis group had thicker LVMWT(P=0.008),higher left ventricular mass index(LVMI)(P=0.001),higher left ventricular end diastolic volume(LVEDV)(P=0.043),lower left ventricular ejection fraction(LVEF)and cardiac index(CI)(all P<0.05).The levels of NT-proBNP and cTnI were significantly higher in fibrosis group than in non-fibrosis group(2760.5(1503.4,3783.6)ng/L vs.861.3(552.2,1092.8)ng/L,P=0.002;0.970(0.448,1.684)μg/L vs.0.147(0.033,0.251)μg/L,P=0.041).In fibrosis group,there were 15 cases of mild hypertrophy(mild hypertrophy group),10 cases of moderate hypertrophy(moderate hypertrophy group),and 9 cases of severe hypertrophy(severe hypertrophy group).The LGE%and NT-proBNP and cTnI increased in proportion with increasing myocardial hypertrophy(P<0.05).LGE%was negatively correlated with age(r=-0.618,P=0.011),and positively correlated with NT-proBNP and cTnI levels(r=0.271,P=0.010;r=0.111,P=0.013,respectively),and positively correlated with LVEDV,LVMWT and LVMI(r=0.438,P=0.09;r=0.735,P=0.001;r=0.532,P=0.034,respectively).Conclusions In patients with hypertrophic cardiomyopathy,the extent of myocardial fibrosis increases with the increase of myocardial hypertrophy.Myocardial fibrosis is negatively correlated with age,and positively correlated with NT-proBNP and cTnI,as well as LVEDV,LVMWT and LVMI in this patient cohort.