| Part I Right Ventricular Function Assessed by Echocardiography in Type 2Diabetes Mellitus with Different Hb A1 c LevelsObjectives: Higher glycated hemoglobin A1c(Hb A1c)level was a significant risk factor for cardiovascular diseases and heart failure in type 2 diabetes mellitus(T2DM).Previous studies have reported that T2 DM was associated with impaired RV function.However,it is not clear whether T2 DM patients with increased Hb A1 c levels had more marked impaired RV function.We aimed to assess RV function by echocardiography in T2 DM with different Hb A1 c levels,and to explore whether Hb A1 c levels was independently associated with RV function.Methods: A total of 94 T2 DM patients 63 controls with normal glucose metabolism who underwent conventional and three-dimensional echocardiography at Wuhan Union hospital between December 2019 and December 2020 were studied.T2 DM patients were categorized into three subgroups according to Hb A1 c levels(group A: < 6.5%,group B:6.5% ～ 7.5%,group C: > 7.5%).Conventional RV function parameters included S’,RV fractional area change(RVFAC)and tricuspid annular plane systolic excursion(TAPSE)were measured.Non-invasive pulmonary vascular resistance(PVR)and pulmonary arterial systolic pressure(PASP)were estimated by echocardiography.RV free-wall longitudinal strain(RVFWLS)was acquired by two-dimensional speckle-tracking echocardiography and RV volumes,RV ejection fraction(RVEF)were derived from three-dimensional echocardiography.We performed multiple linear regression analyses adjusted for covariates were used to determine the association of Hb A1 c levels with RV structure and function.Results: 1)No statistical differences were found in gender,age,body mass index,heart rate between the three T2 DM subgroups and controls.(P > 0.05 for all).In the T2 DM subgroup analyses,groups with higher Hb A1 c levels had a higher SBP(P trend = 0.025),higher LDL(P trend = 0.035)and fasting blood glucose levels(P trend = 0.014),they were more prone to receive insulin treatments.While the duration of diabetes showed no significant trend from group A to group C(P trend = 0.493).2)Compared with controls,all the three T2 DM subgroups had a higher tricuspid E/e’ratio(P < 0.01 for all),lower RVFWLS and RVEF(P < 0.01 for all).No statistical differences were found in RVFAC,TAPSE and S’ between the three T2 DM subgroups and controls(P > 0.05 for all).Moreover,group B and C had increased PASP(P < 0.01 for both)and lower RVFWLS/PASP ratio(P < 0.01 for both)than controls.3)In T2 DM subgroup analyses,patients with higher Hb A1 c had increased tricuspid E/e’ ratio(P for trend = 0.002),significant lower RVFWLS(P trend < 0.001)and RVEF(P trend = 0.006).While conventional RV systolic function parameters(TAPSE,S’ and FAC)were similar among the three subgroups(P trend > 0.05 for all).In addition,T2 DM patients with higher Hb A1 c also had increased PASP and PVR,as well as a lower RVFWLS/PASP ratio.4)After adjustment for age,systolic blood pressure,estimated glomerular filtration rate,low-density lipoprotein,diabetes duration,use of insulin treatment,left ventricular mass index and mitral E/e’ ratio,the trend for significant higher E/e’ ratio(P trend = 0.013),lower RVFWLS(P trend < 0.001)and RVEF(P trend = 0.039)also persisted in patients with higher Hb A1 c levels,while the trends for conventional RV systolic function measures were not significant.In addition,there was an increasing trend in PASP from group A to group C,despite the trend analysis showing no statistically significant(P trend = 0.075).The trend for increased PVR and lower RVFWLS/PASP ratio(P trend < 0.001 for both)persisted in patients with higher Hb A1 c levels.Conclusions: RV diastolic and systolic function declined progressively across Hb A1 c levels in T2 DM.Poor glycemic control was associated with decreased RV diastolic and systolic function independent of known cardiovascular risk factors.Moreover,RVFWLS and RVEF allow more accurate reflection of the effects of hyperglycemia on RV systolic function than conventional RV function measures.Part II Prognostic Value of Right Ventricular Function Assessed by Echocardiography in Type 2 Diabetes MellitusObjectives: Type 2 diabetes mellitus(T2DM)was associated with cardiovascular outcomes,hospitalization and worse prognosis.Previous studies have reported that T2 DM was associated with impaired right ventricular(RV)function.RV dysfunction was considered as a robust predictor in various cardiovascular diseases.While the prognostic value of the right ventricular function in T2 DM patients was rare.This study aimed to assess the predictive value of RV function assessed by echocardiography for adverse events in adult T2 DM.Methods: This study enrolled 280 T2 DM individuals with normal left ventricular ejection fraction(LVEF)who were under routine echocardiographic examination at Wuhan Union hospital between December 2016 and December 2020.Conventional RV function parameters included tricuspid annular plane systolic excursion(TAPSE)and RV fractional area change(RVFAC)were measured.RV free-wall longitudinal strain(RVFWLS)was acquired from two-dimensional speckle-tracking echocardiography and RV ejection fraction(RVEF)was acquired from three-dimensional echocardiography.Patients were followed up for primary end point defined as cardiovascular event(CVE)events included coronary revascularization,myocardial infarction,heart failure requiring hospitalization,stroke,cardiac death.The clinical outcomes were followed up to December 31,2021.Results: 1)In our study,the mean age was 59 ± 9 years and the median duration of T2 DM was 8.0 years(inter quartile range: 3.0 ~ 12.0 years).During a median follow-up of 32.0 months(range: 6.0 ~ 71.2 months),a total of 39 patients reached the primary end point.The study population was divided into group without CVE(n = 241)and group with CVE(n = 39).2)Compared with group without CVE,patients with CVE were elder,they had higher Hb A1 c levels and higher proportions of hypertension and coronary artery disease.The T2 DM duration was similar between these two groups.3)Compared with group without CVE,patients with CVE had lower RVFWLS and increased mitral E/e’ratio.While the significant difference in LVEF,RVEF,RVFAC and TAPSE between these two groups was not found in this study.4)In univariate Cox analysis,TASPE、RVFAC and RVEF were not associated with CVE in T2 DM,while decreased RVFWLS was significant associated with a higher risk of CVE.After adjusting for age,history of coronary artery disease and Hb A1 c levels in multivariate analysis,mitral E/e’ratio(HR:1.078,95%CI:1.011 ~ 1.150,P = 0.023)and RVFWLS(HR:1.259,95%CI:1.146 ~ 1.384,P = 0.001)were independent predictors for CVE in T2 DM.Moreover,RVFWLS provided incremental prognostic information in addition to clinical data(age,history of coronary artery disease,Hb A1 c levels)and mitral E/e’ratio(Chi-square to improve: 24.90,P < 0.001).Receiver?operator characteristic curve analysis revealed that RVFWLS(AUC 0.786,P < 0.001)were strong predictors of CVE in T2 DM.Kaplan-Meier analysis showed that the risk of CVE was significant higher in T2 DM patients with RVFWLS >-19.8 % than those with RVFWLS ≤-19.8 %(Log-rank P < 0001).Conclusions: RVFWLS was an independent predictor for CVE in T2 DM with preserved LVEF.RVFWLS provides additional prognostic value to known clinical risk factors,Hb A1 c and LV diastolic function in T2 DM patients. |
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