The Significance Of Initial Ventricular Septal Depolarization,lymphatic Microvessels,and ABO Blood Type In Patients With Hypertrophic Cardiomyopathy

Part One:A study of the relationship between initial ventricular septal depolarization and outcome of percutaneous transluminal septal myocardial ablation in patients with hypertrophic obstructive cardiomyopathyObjectives:Percutaneous transluminal septal myocardial ablation(PTSMA)is one of the septal reduction therapies with satisfactory results not in all hypertrophic obstructive cardiomyopathy(HOCM)patients.Septal r-wave(initial r-wave in lead aVR)and septal q-wave(initial q-wave in leads V3-V6)on the surface electrocardiography are both signs of initial ventricular septal depolarization.Whether initial ventricular septal depolarization with predictive of good or worse response to PTSMA in HOCM patients has been unknownMethods:Among 546 consecutive patients evaluated in Fuwai Hospital(Beijing,China),we selected HOCM patients who underwent PTSMA.Composite endpoint was defined as surgical myectomy,death,pacemaker implantation,and NYHA classification Ⅲ/ⅣResults:84 patients were enrolled consecutively,and median follow-up time was 5(3-7)years after PTSMA.There were 2(2.4%)patient death,11(13.1%)patients with surgical myectomy,1(1.2%)patients with pacemaker implantation for complete heart block,and 31(36.9%)patients with NYHA classification Ⅲ/Ⅳ.Multivariable COX analysis identified initial q-wave(HR 3.661(1.801-7.439),p<0.001)and initial r-wave(HR 0.257(0.116-0.573),p=0.001)as independent predictors of the composite endpoint outcomes.Compared patients with septal q-wave and without septal r-wave,patients without or with both septal q-wave and septal r-wave were independently associated with decreased risk of composite endpoint(HR:0.273,95%CI:0.134-0.555,p<0.001 or HR:0.257,95%CI 0.116-0.573,p=0.001).Conclusions:The results suggest that the presence of initial ventricular septal depolarization in leads V3-V6 and aVR could predict longterm outcome after PTSMA.The patients with initial ventricular septal depolarization only in V3-V6 benefit less than other type of patients after PTSMA procedure.Part Two:A study of the relationship between lymphatic microvessels and myocardial fibrosis in patients with hypertrophic obstructive cardiomyopathyObjectives:Lymphatic microvessel density(LMVD)is closely associated with myocardial fibrosis in patients with myocardial infarction.The role of LMV in HOCM is unclear.We aim to investigate the relationship between LMVD and myocardial fibrosis in hypertrophic obstructive cardiomyopathy(HOCM)patients.Methods:We studied LMVD in ventricular septal(VS)samples from 52 individuals(42 was HOCM patients who underwent a transaortic extended septal myectomy,and 10 individuals from accidental death),and examined the relationships between the LMVD stained immunohistochemically with lymphatic vessel endothelial hyaluronan receptor(LYVE-1)antibodies,clinical characteristics,and collagen volume fraction(CVF).Results:Compared with group traffic death,LMVD was significantly increased in VS of HOCM patients(132.0±49.0 VS 57.8±48.8/mm2,p=0.000).HOCM patients with syncope had higher level of LMVD than without syncope(166.7(131.0-201.1)VS 116.4(80.7-152.1)/mm2,p=0.017).LMVD were positively correlated with Ln(CVF)(r=0.431,P=0.004).On multiple variables regression analysis,LMVD was independently associated with syncope(r=0.384,p=0.010)and Ln(CVF)(r=0.346,p=0.018).Conclusions:In HOCM patients,the LYVE-1 positive lymphatics might play an important role in VS fibrosis.Part Three:A study of the relationship between ABO blood type and clinical feature in patients with hypertrophic cardiomyopathy.Objectives:ABO blood type is associated with cardiovascular diseases.Several studies have suggested sex-related differences in both hypertrophic cardiomyopathy(HCM)clinical features and ABO blood type.However,few data are available regarding the relationship between ABO blood type and HCM clinical features.We aimed to analyze the relationship between ABO blood type and HCM clinical features,and the potential effects of sex on these relationships.Methods:A total of 549 patients with HCM were enrolled consecutively.Left ventricular outflow tract gradients at rest(LOVTG-R)were measured by echocardiography.Left ventricular end-diastolic dimension,interventricular septum,left ventricular ejection fraction(LVEF),left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),and left ventricular mass(LVM)were assessed using cardiovascular magnetic resonance imaging.Results:Compared with the non-B antigen group,patients with B antigen had significantly higher LOVTG-R and LVEF values,worse New York Heart Association(NYHA)classification,lower left ventricular volume index values,as well as no difference in LVM index values.After adjustments for sex,male patients with B antigen still had higher LOVTG-R values and frequency of NYHA classification III/IV as well as lower LVEDV and LVESV index values.These differences were not present in female patients.Additionally,patients with NYHA classification III/IV had lower LVEDV index values.Conclusions:In males,not females,patients with HCM with blood type B antigens exhibited worse cardiac functional capacity,higher LOVTG-R values,and lower left ventricular volume index values.These relationships are a potential indicator for clinical prevention.