The Value Of Myocardial Strain Parameters Of Cardiac Magnetic Resonance In Identifying Whether Hypertrophic Cardiomyopathy Patients Occur Ventricular Arrhythmias

ObjectiveTo assess myocardial strain in hypertrophic cardiomyopathy?HCM?by cardiac magnetic resonance tissue tracking?CMR-TT?,and to further explore the value of myocardial strain parameters in identifying whether HCM patients occur ventricular arrhythmias?VAs?.Materials and methodsWe retrospectively enrolled 93 patients with HCM diagnosed in our hospital from January 2013 to September 2019,including 38 HCM patients with VAs and 55 HCM patients without VAs,and 30 normal people were included as the control group.All cine and late gadolinium enhancement?LGE?images were imported into CVI⁴²post-processing software for analysis to obtain routine cardiac function parameters,left cardiac morphology parameters,left ventricular myocardial strain parameters and LGE percentage.Independent sample t-test or Wilcoxon signed-rank test were used to compare the differences between HCM patients and normal people,HCM with VAs and HCM without VAs.Univariate and multivariate logistic regression analysis were used to determine the risk factors of VAs in HCM.The diagnostic value of myocardial strain parameters and LGE percentage for HCM with VAS was obtained from the receiver operating characteristic?ROC?.The correlation between myocardial strain parameters and LGE percentage was analyzed by Spearman correlation test.ResultsCompared with control group,HCM patients had increased left ventricular ejection fraction?LVEF??P<0.001?,but their global radial strain?GRS?,global circumferential strain?GCS?,global longitudinal strain?GLS?,global radial strain of diastolic rate?GRSDr?,global circumferential strain of diastolic rate?GCSDr?and global longitudinal strain of diastolic rate?GLSDr?were significantly decreased?all P values<0.01?.Left ventricular mass index?LVMI?,left atrial anteroposterior diameter?LAD-AP?and left ventricular maximal wall thickness?LVMWT?in HCM patients were significantly increased?all P values<0.001?.Compared to HCM patients without VAs,HCM patients with VAs had lower LVEF?P<0.01?,but increased LAD-AP?P<0.01?,thicker LVMWT?P<0.01?,and more LGE percentage?P<0.001?.Multivariate logistic regression analysis showed that LGE percentage and GCS were independent risk factors of VAs in HCM patients.ROC analysis showed that HCM patients associated with VAs could be effectively identified when LGE percentage over 5.35%or GCS less than-14.73%.When combined with LGE percentage and GCS to diagnose HCM with VAs,the area under curve?AUC?was 0.87[95%CI?0.79,0.95?,P<0.001],which was better than the diagnostic performance of the two indicators alone?AUC was 0.81 and0.79 respectively?.Conclusion1.In the early stage of HCM,the routine left cardiac function is still in the normal range or even increased.Myocardial strain parameters explored based on CMR-TT could detect myocardial damage in HCM patients early.2.LGE percentage and GCS were both independent risk factors for VAs in HCM patients.The combination of the two indicators could improve the detection of VAs in HCM patients.3.For patients who are unable to undergo LGE scan due to some reasons such as renal failure,GCS is expected to become a new parameter to assess whether HCM patients occur VAs,which can provide some imaging evidence for clinical diagnosis and treatment and patient prognosis.