Analysis Of Clinical Features And Prognosis Of Patients With Different Types Of Hypertrophic Cardiomyopathy

Background and Aims : Hypertrophic cardiomyopathy(HCM)is an inherited myocardial disease characterized by thickening of the left ventricle or right ventricle wall that cannot be explained by secondary causes.Asymmetric septal hypertrophic cardiomyopathy(ASHCM)is more common,while apical hypertrophic cardiomyopathy(AHCM)is relatively rare.The myocardial thickening site of AHCM mainly involves the left ventricular apex,which is usually non-obstructive HCM,and its variable manifestations and clinical characteristics often make it misdiagnosed or missed.At present,there are few comparative studies on AHCM and ASHCM at home and abroad,and the differences between them are still controversial.The article aims to summarize and analyze the clinical characteristics and long-term prognosis of patients with different types of hypertrophic cardiomyopathy.Methods:We collected and summarized the hospitalization data of patients with HCM in Gulou Hospital Affiliated to Medical College of Nanjing University from January 2010 to March 2019,then divided them into AHCM(170 cases)and ASHCM(238 cases)group according to the anatomical classification,and recorded prognosis by regular follow-up of telephone or outpatient,and divided them into SCD(11 cases)and non-SCD(334 cases)group according to the occurrence of sudden cardiac death(SCD)during the follow-up,then did a retrospective analysis by SPSS.Result:A total of 408 patients were enrolled,including 259 males(63.50%),whose age of diagnosis was(58.90±13.79)years old.Compared with the AHCM group,there were more female patients,longer hospitalization days,lower systolic blood pressure at first diagnosis,higher SCD score and prognostic index,and more patients with family genetic history of HCM and family history of SCD in the ASHCM group;in terms of previous history,there were fewer patients with angina pectoris in the ASHCM group;in terms of clinical manifestations,there were fewer asymptomatic patients,more patients with palpitation symptoms and heart auscultation with HCM murmur;in terms of conventional electrocardiogram,there were fewer ST-T changes,fewer high left ventricular voltage,fewer ST segment downshift,fewer T wave inversion,more highgrade atrioventricular block,more pathological Q wave and non-sustained ventricular tachycardia(NSVT)in the ASHCM group;in terms of laboratory examination,there were higher levels of troponin T,white blood cell count,urea nitrogen and C-reactive protein,and lower levels of hemoglobin in the ASHCM group;in terms of echocardiography,there were higher levels of left atrium diameter(LAD),interventricular septun thickness diastolic(IVSTd),left ventricular posterior wall thickness diastolic(LVPWTd),A peak of mitral orifice flow(A),aortic diameter(Ao),the ratio of E peak of mitral orifice flow(E)to E? peak of mitral annulus(E/E?),and higher percentage of left ventricular outflow tract obstruction(LVOTO)and moderate mitral regurgitation,while lower levels of left ventricular end diastolic dimension(LVDd),the ratio of E peak to A peak in mitral flow(E/A),left ventricular ejection fraction(LVEF),and lower percentage of mild mitral regurgitation in the ASHCM group;in terms of treatment methods,there were lower percentage of medical treatment and nitrate drugs,higher percentage of surgical treatment and diuretics in the ASHCM group;in terms of surgical treatment,there were higher percentage of undergoing chemical ablation,surgical ventricular septal myocardial resection,and pacemaker implantation in the ASHCM group;the differences between the above two groups were statistically significant(all P<0.05).All patients were followed up by clinic or telephone from make a definite diagnosis to October 2019,63 patients were lost to follow-up,and the follow-up period of the remaining patients was(39.10±21.55) months.Compared with the AHCM group,patients in the ASHCM group had a higher proportion of readmission with aggravated symptoms,decompensation of heart failure and SCD,and the differences between the two groups were statistically significant(all P<0.05),while the differences in other clinical characteristics and prognosis between the two groups were not statistically significant(P>0.05).Compared with the non-SCD group,patients in the SCD group had a higher proportion of patients with ASHCM,family genetic history of HCM,family history of SCD,history of unexplained syncope,history of heart failure,heart auscultation with HCM murmur,asthma symptoms,NSVT,LVOTO,mildly elevated pulmonary systolic pressure and diuretic treatment,while patients in the SCD group had lower levels of free triiodothyronine(FT3).During the follow-up,patients in the SCD group had a higher proportion of readmission with aggravated symptoms,decompensation of heart failure and malignant arrhythmia.The differences between the above two groups were statistically significant(all P<0.05).Multivariate COX regression analysis showed that the family history of SCD(HR=11.795,95% CI: 1.616~86.095,P=0.015)and NSVT(HR=10.049,95% CI: 1.178~85.692,P=0.035)were independent risk factors of SCD.Kaplan-Meier survival analysis showed that in terms of follow-up endpoint event SCD,patients with ASHCM,history of unexplained syncope,history of heart failure,family genetic history of HCM,family history of SCD,NSVT,asthma symptoms,heart auscultation with HCM murmur,wall thickness?3cm,mildly elevated pulmonary systolic pressure,LVOTO,readmission with aggravated symptoms and decompensation of heart failure of followup period had lower survival rate and worse prognosis(all P <0.05).Conclusions:There are statistical differences in clinical characteristics and prognosis between patients with AHCM and ASHCM,and so were patients with non-SCD and SCD.Compared with patients with ASHCM,the prognosis of patients with AHCM was relatively good,and the family history of SCD and NSVT were independent risk factors for SCD in patients with HCM.