Value Of MRI Multi-parameter In Diffuse Myocardial Fibrosis Of HCM And Its Correlation With Left Atrial Function

Objective:To explore whether left ventricular interstitial fibrosis is associate with left atrial enlargement and left atrial dysfunction in patients of hypertrophic cardiomyopathy（HCM）by cardiac magnetic resonance（CMR）.Methods:From October 2018 to September 2021,59 HCM（30 with left atrial enlargement,29 without left atrial enlargement）and 28 age-and gender-matched controls who underwent 3.0 T CMR examination were retrospectively enrolled.Imaging protocol included cine sequence,late gadolinium enhancement and T1mapping.Left ventricular variables including mass,volume,strain and fibrosis were measured and compared.Biplane area-length was performed,with parameters including maximal left atrial volume index(LAVI_max),just prior to left atrial contraction volume index(LAVI_pac),minimal left atrial volume index(LAVI_min),left atrial ejection fraction of reservoir(LAEF_reservoir),left atrial ejection fraction of conduit(LAEF_conduit),and left atrial ejection fraction of pump(LAEF_pump)derived.One-way analysis of variance with Bonferroni post hoc correction or Kruskal-Wallis was performed for continuous variables.Comparison of the continuous variables between the two groups was performed by independent t tests and Mann-Whitney U tests.Categorical variables were assessed using the Chi-square test or Fisher’s exact test.Pearson or Spearman was used for linear or monotonic nonlinear correlations.Results:The GCS、GLS、SLSR_peak、DLSR_peakof HCM with LAE group and HCM without LAE group were all reduced than control group（P<0.05）.The LVEDVI、LVESVI、LVCO and LVMI of HCM with LAE group were higher than HCM without LAE group and control group（P<0.05）.Correlation analysis showed that LVMI correlated positively with LAVI_max（r=0.780,P=0.000）and LAVI_min（r=0.816,P=0.000）,ECV correlated positively with LAVI_max（r=0.462,P=0.000）,LAVI_min（r=0.483,P=0.000）,left ventricular index interstitial volume correlated negatively with LAEF_reservoir（r=-0.669,P=0.000）,LAEF_conduit（r=-0.472,P=0.001）,LAEF_pump（r=-0.518,P=0.000）and left atrial expansion index（r=-0,626,P=0.000）.Conclusion:There is association between LVMI and fibrosis and left atrial enlargement and phases dysfunction.