Arrhythmias And Left Ventricular Remodeling In Patients With Hypertrophic Obstructive Cardiomyopathy

Part One:The Predictive Value of Epicardial Adipose Tissue for Atrial Fibrillation in Patients with Hypertrophic Obstructive CardiomyopathyObjectives:Atrial fibrillation(AF)is the most common arrhythmia,and it potentially increase the risk of embolic stroke and aggravate heart failure(HF)in patients with hypertrophic cardiomyopathy(HCM).Recent studies demonstrated that epicardial adipose tissue(EAT)was closely associated with AF in general populations.However,the relationship between epicardial adipose tissue volume(EATV)and the presence of AF in patients with HCM remains unclear.We sought to evaluate whether EATV measured by cardiac magnetic resonance(CMR)was related with AF and determine the predictive value of EATV for identifying AF in patients with HOCM.Methods:A total of 93 consecutive patients with hypertrophic obstructive cardiomyopathy(HOCM)were enrolled in our study.There were 18 HOCM patients with a history of AF and 75 HOCM patients without it.Clinical evaluations for all participants were performed,including collection of demographic characteristics and medical history,12-lead electrocardiography,24-h Holter monitoring,echocardiography,blood tests,and CMR imaging.EATV and left atrial volume(LAV)were determined by E-3D medical model software and indexed to body surface area.Results:The mean epicardial adipose tissue volume index(EATVI)of participants was 132.0±33.7 mL/m2.HOCM patients with AF had significantly greater EATVI(156.4±29.0 mL/m2vs.126.1±32.2 mL/m2,P<0.001),left atrial volume index(LAVI,91.3±30.9 mL/m2 vs.66.2±21.3 mL/m2,P<0.001)and left ventricular end-systole volume index(LVESVI,31.6±8.5 mL/m2 vs.25.99±10.6 mL/m2,P=0.039),and lower left ventricular ejection fraction(LVEF,59.5±8.6%vs.66.4±8.4,P=0.002).In multivariable logistic regression analysis,EATVI,LAVI,and LVEF remained independent determinants of AF occurrence(odds ratio(OR)=1.023,95%confidence interval(CI),1.003-1.043,P=0.023;OR=1.043,95%CI,1.012-1.075,P=0.006;and OR=0.887,95%CI,0.818-0.962,P=0.004,respectively).Furthermore,receiver operating characteristic(ROC)curve analysis demonstrated that integration of EATVI,LAVI and LVEF provided better discriminatory performance for incident AF in HOCM with a high sensitivity of 94.4%and a specificity of 69.3%(AUC=0.864,95%CI,0.771-0.958,P<0.001).Conclusions:EATVI is an independent predictor of the presence of AF,and integration of EATVI,LVEF and LAVI determined by CMR provide greater discriminatory performance for identifying AF in patients with HOCM.It may be reasonable and beneficial for HOCM patients underwent CMR imaging evaluation to quantify EAT volume and estimate the risk of incident AF.Part Two:The Relationship between Cardiac Troponin I and Non-sustained Ventricular Tachycardia in Patients with Hypertrophic Obstructive CardiomyopathyObjectives:As highly sensitive and specific markers of myocardial damage,cardiac troponins were demonstrated to correlate with clinical parameters of patients with hypertrophic cardiomyopathy(HCM).However,the relationship between cardiac troponins and presence of non-sustained ventricular tachycardia(NSVT)in HCM remains unclear.The aim of our study was to explore the association between serum cardiac troponin I(cTNI)and presence of NSVT in patients with hypertrophic obstructive cardiomyopathy(HOCM).Methods:A total of consecutive 309 patients with HOCM were enrolled in our study.All participants underwent clinical evaluations,including collections of demographic characteristics and medical history,blood tests,12-lead electrocardiography,24-h Holter monitoring,echocardiography,and cardiac magnetic resonance imaging.Results:There were 53(17.2%)patients with NSVT and 256 patients without it in our present study.Compared to patients without NSVT,serum cTNI(P<0.001)and plasma N-terminal pro-B-type natriuretic peptide(NT-proBNP,P=0.042)were significantly higher in patients with NSVT.Moreover,log cTNI and log NT-proBNP were positively correlated with left atrial diameter,maximum wall thickness(MWT),left ventricular volume index and left ventricular mass index.In multivariable logistic analysis,log cTNI(odds ratio(OR)=2.408,95%confidence interval(CI),1.108-5.325,P=0.027),left ventricular end-diastole diameter(LVEDD,OR=0.922,95%CI,0.856-0.994,P=0.034),MWT(OR=1.131,95%CI,1.035-1.235,P=0.006)and left ventricular end-systole volume index(LVESVI,OR=1.060,95%CI,1.025-1.096,P=0.001)were independent determinants of NSVT occurrence after adjustment for potential cofounders.Conclusions:Our results demonstrated serum cTNI level was elevated in patients with NSVT.And it was independently associated with NSVT in patients with HOCM.It may be reasonable for HOCM patients with elevated serum cTNI to extend the time of Holter monitoring.Part Three:Sex-related differences in the impact of primary hypertension on left ventricular remodeling in patients with hypertrophic obstructive cardiomyopathyObjectives:The clinical condition of hypertrophic obstructive cardiomyopathy(HOCM)and concomitant primary hypertension is growing more and more prevalent and it brings about a challenging diagnostic and therapeutic dilemma.However,whether primary hypertension has an impact on HOCM,and whether sex-related differences exist in this impact,remains unclear.Methods:A total of consecutive 453 HOCM patients(age 48.7±12.8 years,252(55.6%)males)were recruited in this study.There were 150 patients(33.1%,81 males and 69 females)with a history of controlled primary hypertension.Collections of demographic characteristics and medical history,12-lead electrocardiography,24-h Holter monitoring,echocardiography,blood tests and cardiac magnetic resonance(CMR)imaging were performed in all patients.Left ventricular remodeling index(LVRI)were determined by CMR.LORI>1.3 g/mL was defined as pathological left ventricular(LU)remodeling.Results:Men had significantly greater LVRI(1.40±0.54 g/mL vs.1.15±0.38 g/mL,P<0.001),and LVRI>1.3 g/mL(P=0.002),compared with women.The incidence of syncope and 5-year sudden cardiac death risk score were significantly lower in HOCM with hypertension than those without hypertension.LVRI(P=0.003)and LVRI>1.3 g/mL(P=0.007)were significantly smaller in males with hypertension,but not in females with hypertension.However,log cardiac troponin I(cTNI)and log N-terminal pro-B-type natriuretic peptide(NT-proBNP)was positively correlated with LVRI in men and women.In multivariable logistic analysis,hypertension(OR=0.172,95%confidence interval(CI),0.056-0.528,P=0.002)remained an independent determinant of pathological LV remodeling in males,whereas not in females.Conclusions:There were significant sex differences in the impact of primary hypertension on LV remodeling in patients with HOCM.Controlled primary hypertension may contribute to improving LV remodeling in male patients with HOCM,but not in females.