Quantitative Evaluation Of Left Atrial Function In Hypertension Patients With HFpEF By Cardiovascular Magnetic Resonance Tissue Tracking

ObjectiveCardiovascular magnetic resonance-tissue tracking（CMR-TT）was used to quantitatively analyze the left atrial（LA）strain and strain rate strain and strain rate in hypertensive patients with heart failure with preserved ejection fraction（HFp EF）,which objective was to investigate the clinical application value of CMR-TT in evaluating left atrial function in hypertensive patients with HFp EF.Material and MethodA retrospective analysis was conducted on 54 patients who were admitted to our hospital from August 2018 to September 2021,including 24 patients with clinically confirmed hypertension with HFp EF（HTN-HFp EF）and 30 patients with isolated hypertension（without HFp EF）.Another 30 healthy volunteers were collected named the control group.All subjects underwent CMR on a 3.0T magnetic resonance device,using standard breath-holding steady-state free precession for film imaging.The LA related parameters were obtained by cardiovascular post-processing software CVI42,including strain,volume and functional parameters.The LA strain parameters include total strainεs,passive strainεe,active strainεa.The strain rate parameters of LA include positive strain rate peak SRs,negative strain rate peak SRe in early diastole,and negative strain rate peak SRa in late diastole.Left atrial volume parameters include left atrial minimum volume LAVmin,left atrial maximum volume LAVmax and left atrial volume index LAVI.Left atrial function parameters include left atrial total ejection fraction LATEF,LA passive emptying fraction LAPEF and LA active emptying fraction LAAEF.All patients and control group received serological brain natriuretic peptide（BNP）detection and recorded the results.ANOVA or Kruskal Wallis test with related post-hoc test was used to compare the parameters between the three groups.Binary logistic regression was used to determine the risk factors for HFp EF.ROC curve analysis was performed to evaluate the diagnostic efficacy of HFp EF,cut-off value and diagnostic efficacy of HFp EF were obtained as well.Spearman correlation was used to analyze the correlation between LA strain and BNP parameters.Result（1）Analysis of LA strain parameters:In the HTN-HFp EF group,HTN group and control group,the mean levels ofεs、εe、SRs and SRe increased successively,and the differences were statistically significant（all P<0.05）in three groups.The mean level ofεa and SRa in HTN-HFp EF group was lower than that in HTN group and control group,and there were statistically differences respectively（both P<0.05）.There was no significant difference inεa and SRa between the HTN group and control group.Theεs（%）of the three groups were 17.70（14.65,19.70）,25.35（21.80,27.25）and39.28±7.57.εe（%）:7.83±2.86,11.49±2.64 and 24.29±6.26.εa（%）:9.08±3.19,13.49±4.30,14.99±3.90.SRs(S^-1):-0.60（-0.90,-0.50）,-1.11±0.37 and-2.20（-1.90,-2.48）.SRe(S^-1):-0.60（-0.90,-0.50）,-1.11±0.37 and-2.20（-1.90,-2.48）.SRa(S^-1):-1.10±0.47,-1.67±0.56 and-1.95（-1.48,-2.23）.（2）Analysis of LA volume parameters:In the HTN-HFp EF group,HTN group and control group,the average level of LAVmin decreased successively,and the difference was statistically significant（all P<0.05）when compared in pairs.LAVmin（ml）in each group were 36.67（30.73,48.83）,26.91（20.69,30.98）and 15.62（13.22,17.56）respectively.The average level of LAVmax in the HTN-HFp EF group and HTN group was higher than that in the control group,and the difference between the two groups was statistically significant（P<0.05）,but there was no statistical difference between the HTN-HFp EF group and the HTN group.LAVmax（ml）of the three groups were 72.11（63.89,90.93）,61.24（52.02,80.94）and 48.62（42.99,55.51）respectively.There were statistically significant differences in LAVI between the HTN-HFp EF group and the HTN group,and between the HTN-HFp EF group and the control group（P<0.05）,but there were no statistically significant differences between the HTN group and the control group.LAVI were 41.73（35.88,53.67）,35.45（29.42,41.84）and29.43（26.13,35.15）respectively in three groups.（3）Analysis of LA emptying fraction parameters:LATEF and LAPEF increased successively in HTN-HFp EF group,HTN group and control group,and the differences were statistically significant（P<0.05）.LATEF（%）in the three groups was 47.59±8.91,57.88±6.03 and 67.46±4.59 respectively.LAPEF（%）were 20.65±7.29,29.03±5.36 and 41.47±5.64 respectively.LAAEF（%）were 26.99（21.54,32.68）,28.71（24.28,33.88）and 24.81（22.26,29.75）respectively in three groups.（4）Logistic regression demonstrated thatεs was an independent risk factor for HFp EF（odds ratio:2.37,P<0.05）,the optimal cut-off value ofεs in the diagnosis of HFp EF by ROC curve was 19.55%,the sensitivity and specificity of HFp EF were 96.7%and 75%respectively.There was a good correlation between LA strain myocardial parameters（εs,εe,εa,SRs,SRe,SRa）and BNP（correlation coefficients r were-0.844,-0.752,-0.539,-0.652,-0.756,-0.545 respectively）.ConclusionCMR-TT can be used to assess changes in LA function sensitively by quantitative measurement of LA strain.The LA reservoir function（εs）,conduit function（εe）and pump function（εa）were significantly impaired in HTN-HFp EF patients.LA strain parametersεs has potential value in the diagnosis of HFp EF.