Correlation And Clinical Significance Of Late Enhancement Rate Of MRI And Sudden Cardiac Death Caused By Hypertrophic Cardiomyopathy

BackgroundHypertrophic cardiomyopathy(HCM)is a common disease in non-ischemic cardiomyopathy.It is caused by a mutation in the gene encoding sarcomeric proteins controlling myocardial cells on the chromosome,and is an autosomal dominant genetic disease.HCM is a common disease of sudden cardiac death(SCD)in young people,especially athletes.For sudden cardiac death in patients with hypertrophic cardiomyopathy,the first-level effective preventive measure is to give an implantable cardioverter-defibrillator(ICD).Therefore,it is significant and challenging to conduct an SCD risk assessment of HCM patients and guide patients to perform primary prevention of ICD implantation.The 2014 European Society of Cardiology(ESC)guidelines proposed a new model to assess SCD risk to guide ICD treatment.According to the results of the new model,patients with hypertrophic cardiomyopathy can be divided into three groups: low-risk,intermediate-risk,and high-risk.ICD should be implanted in high-risk patients,ICD are not recommended for low-risk patients,and ICD can be considered in mid-risk patients,depending on the specific situation.In recent years,with the development of cardiac magnetic resonance imaging(CMRI)technology,the late gadolinium enhancement(LGE)technology of CMR can better observe myocardial fibrosis,it has become an alternative to the invasive examination of endocardial biopsy to observe the morphological and histological changes of the heart,myocardial fibrosis is one of the main manifestations of HCM pathology.Studies have shown that LGE is associated with an increased risk of SCD events in HCM patients.The quantification of LGE is the LGE rate(the volume is calculated from the sum of the areas of the left ventricular myocardium with delayed reinforcement in each section,and its percentage in the total left ventricular myocardium is calculated),when the LGE rate is greater than 15%,the risk of SCD will increase.Whether the LGE rate is consistent with the new SCD risk model,can it become a risk factor considered in clinical guidance for ICD.We designed and completed this study to explore the relationship between the LGE rate and the new SCD risk model in the real population of HCM,assess whether the LGE rate has added value in different risk groups,and explore the relationship between LGE and end-clinicalevents in HCM patients,SCD The relationship between the model and the clinical end event.Purpose1.To explore the correlation between the CMR-LGE rate of HCM and the new SCD risk prediction model;2.To explore the predictive value of CMR-LGE for clinical end-events in HCM patients;3.To explore the predictive value of SCD risk models for clinical end-events in HCM patients.MethodA total of 30 patients diagnosed with HCM who were admitted to the Huaihe Hospital of Henan University from October 2015 to June 2019 were collected.All patients were subjected to routine clinical evaluation,cardiac ultrasound and cardiac MRI.Use the new SCD risk model proposed by the 2014 ESC Guidelines for risk scoring,which is divided into three groups: low-risk,medium-risk,and high-risk,analyze whether the LGE rate is consistent with the SCD risk scoring model.Subjects were further followed up to explore the relationship between LGE and clinical end events,and the relationship between SCD risk score and clinical end events.Results1.Among the subjects,22 males(73.3%),20 patients(66.7%)were considered low risk,5(16.7%)were considered moderate risk,and 5(16.7%)were considered high risk.2.The LGE rate was positively correlated with the new SCD risk score model(r = 0.943,P<0.001),the LGE rates of the low-risk group,the medium-risk group and the high-risk group were significantly different(3(0,6.08)vs 16 10.25,18.25)vs 17.5(13.4,21.4),P <0.001).LGE rate brings more information to the SCD risk stratification of HCM;LGE may provide additional information for patients with moderate risk,allowing better discrimination to support ICD decision.3.The 5-year SCD scores of patients with LGE were significantly higher than those without LGE(SCD score: 4.49 ± 2.86 vs1.23 ± 0.48;P <0.001).One case of LGE in the low-risk group also showed a wide area;all patients in the medium-risk group and the high-risk group had LGE areas,and 65% of patients in the low-risk group also had LGE.4.30 patients lost 2 follow-ups during the follow-up.All follow-ups were followed up for an average follow-up time of 26.9±12.9(months).One patient in the high-risk group who received primary prevention implanted ICD did not develop SCD,and 2 of the remaining 4 rejected patients developed SCD.A total of 20 end-point events occurred in the follow-up subjects,and 18(90%)LGE(+)cases;in the end clinical events,the LGE(+)group was higher than the LGE(-),which was statistically significant(P<0.05).Compared with the low-risk group,the medium-risk group and the high-risk group,as the 5-year SCD risk stratification increased,the risk of clinical end-events was statistically significant compared with the 5-year SCD risk model(P <0.05).Conclusion1.CMR-LGE quantification is positively correlated with the 5-year SCD risk model of HCM patients(r = 0.943,P <0.001).2.CMR-LGE has predictive value for the occurrence of clinical end events in HCM patients.3.The new SCD risk model has potential predictive value for end-clinical events in HCM patients.