Assessment Of Left Atrial Function In Hypertensive Patients By Cardiac Magnetic Resonance Feature Tracking

Objective:Cardiovascular Magnetic Resonance Feature Tracking（CMR-FT）was used to measure left atrial strain and strain rate in patients with essential hypertension of different left ventricular configurations,To investigate the clinical value of CMR-FT in evaluating left atrial dysfunction inhypertensive patients.Methods:In this study,we retrospectively analyzed 90 patients with essential hypertension which were diagnosed in our hospital from January 2018 to October 2022,And 35 patients who underwent cardiac magnetic resonance health examination were selected as the control group.All patients underwent cardiac magnetic resonance imaging by Siemens Skyra 3.0T MR Routine cardiac function parameters,including LVEF,LVMI,EDVI,ESVI,and CO,were calculated in all subjects using the Siemens Syngovia image workstation cardiac function module.According to left ventricular myocardial mass index（LVMI）,45 hypertensive patients were further divided into hypertension with myocardial hypertrophy group（LVH group）,and45 were divided into hypertension normal configuration group（LVN group）.Software CVI42 was used to calculate left atrial strain and volume parameters in all subjects,Including parameters of left atrial storage function（left atrial total ejection fraction[LATEF],total strain[εs],peak positive strain rate[SRs]）,left atrial catheter function（passive ejection fraction LAPEF],passive strain[εe],peak early negative strain rate[SRe]）and left atrial pump function（active ejection fraction[LAAEF],activestrain[εa],late peaknegativestrain rate[SRa]）.Independent samplet-test,chi-square test,or one-way analysis of variance was used to compare the general clinical data,myocardial strain and atrioventricular volume parameters between the groups.Linear regression analysis was used to analyze the relationship between left atrial strain parameters and influencing factors.The differential diagnostic value of left atrial myocardial strain parameters for hypertensive patients and healthy controls was determined by receiver operating characteristic（ROC）curve analysis.Results:Multiple myocardial strain values were reduced in hypertensive patients compared to healthy controls.(εs[%]:28.4±5.8 vs 31.2±6.2 vs 39.6±6.0,εa[%]:15.5±3.5 vs 16.5±4.0vs 17.2±2.7,εe[%]:12.9±4.7 vs 14.7±5.0 vs 22.6±5.1,SRs[s^-1]:1.25±0.3 vs 1.40±0.31vs 1.77±0.33,SRe[s^-1]:-1.36±0.53 vs-1.60±0.51 vs-2.59±0.51,SRa[s^-1]:-1.41±0.45 vs-1.51±0.40 vs-1.73±0.36).εs,SRs,and SRevalues showed anincreasing trend between LVH,LVN,and healthy controls,the comparisons between each two groups were statistically significant（P<0.01 for all）;εe and SRa were decreased in hypertensive patients compared with the control group,but there was no significant difference in the mean values between LVH and LVN.Compared with the control group,there was no significant difference inεa values in the LVN group,only SRawas decreased,whileεa and SRaweredecreased inthe LVH group.LAVmax and LAVmin values showed a decreasing trend among LVH,LVN,and control groups,but there was a small gap inthe above parameters between the control and LVN groups;LAVpre showed a gradually shrinking trend among the three groups,the differences were statistically significant（LAVmax[ml]68.1±20.4 vs 56.0±17.2 vs 50.6±10.5,LAVmin[ml]32.8±11.8 vs 25.2±9.2 vs 20.1±4.7,LAVpre[ml]52.9±16.7 vs 42.6±13.7 vs 33.7±8.4）.LATEF increased in turn between the three groups,which showed a significant statistical difference（LATEF[%]:52.3±6.8 vs 55.1±6.6 vs 60.2±5.0）;Compared with controls,all hypertensive patients had reduced LAPEF values,but LAPEF was not statistically different between LVH and LVN subgroups（LAPEF[%]:22.6±6.6 vs 24.0±6.9 vs 33.9±6.5）;There was no significantly difference in LAAEF among the there groups（LAAEF[%]:38.4±7.2vs40.94±7.1 vs 39.6±6.3）.LVMI in LVH group was significantly higher than that in control group and LVN group,but there was no significant difference between LVN group and control group;In addition,EDVI and SVI in LVN group were lower than those in normal control group and LVH group,but there was no significant difference between LVH and normal control group.Univariate linear regression of left atrial strain parameters revealed that LVMI and age maybe factors associated with left atrial strain,Adjusted multivariatelinear regression analysis showed thatεs,SRs,and SRe values were independently associated with left ventricular myocardial mass index（β=-0.067,-0.005,0.020,R²=0.078,P<0.05 for all）,εa values were independently associated with age（β=0.061,R²=0.037,P<0.05）,SRe values were linearly related to age（β=0.060,R²=0.281,P=0.001）.The results of ROC curve analysis showed that the optimal cutoff values of SRe for differentiating HTN from healthy people,LVN patients from healthy people were-1.93 and-2.32,respectively,the AUC values were0.928 and 0.915,respectively.The intra-observer and inter-observer correlation coefficients showed that various strain parameters of the left atrium werestable and reproducible.Conclusion:Quantitative analysis of left atrial strain by CMR-FT can comprehensively assess specific changes inleft atrial function inhypertensive patients with high accuracy and reproducibility.Hypertensive patients may already have varying degrees of impaired left atrial storage function and conduit function before left ventricularmorphogenetic remodeling,Impaired pump function,which plays a major compensatory role,occurs at a higher stage of cardiac remodeling.In addition,The left atrial strain parameter SRe has certain clinical value in the differential diagnosis between hypertensive patients with healthy people,and early stage hypertensive patients with healthy people.