Effects Of The Ascending Aorta Dilatation On Arterial Pulsatile Pressure Load And Left Ventricular Afterload In The Hypertensive Elderly

Objective:To determine the effects of ascending aorta dilatation on arterial pulsatile pressure load and left ventricular afterload in elderly hypertensive patients.Methods:A retrospective analysis was conducted on the data of elderly hypertensive patients who admitted the Geriatrics Department of the First Affiliated Hospital of China Medical University from November 2013 to September 2020.The patients were divided into the group with normal aorta and the group with aortic dilatation according to whether the ascending aorta was dilated,and the clinical characteristics were compared between the two groups.The two groups were further divided into four groups according to the status of ascending aortic diameter and pulse pressure(PP)status.Multiple logistic regression was used to analyze the risk of left ventricular hypertrophy(LVH)in the groups with normal aorta and lower PP,normal aorta and higher PP,aortic dilatation and lower PP,and aortic dilatation and higher PP.The relationship between ascending aortic diameter,PP,and left ventricular mass index(LVMI)was explored by using the mediating effect analysis.Results:A total of 1556 patients,74.3%male,aged 60-99 years,with a mean age of 74.89±9.85 years,were included in this study.Compared with the normal aorta group,the aortic dilatation group had a lower proportion of males and smokers,a lower prevalence of diabetes mellitus,more likely with a higher body mass index(BMI),a greater interventricular septal thickness(IVST),left ventricular posterior wall thickness(LVPWT),LVMI,end-diastolic volume(EDV),end-systolic volume(ESV),and stroke volume(SV),a larger aortic annular diameter and Valsalva sinus diameter,and a higher proportion of calcium channel blockers were applied(P<0.05).Age,gender,BMI,history of smoking and drinking,left atrial internal diameter,IVST,left ventricular interior diameter,LVPWT,LVMI,EDV,ESV,SV,E/e’,aortic annulus diameter,Valsalva sinus diameter,aortic sinotubular junction diameter,heart rate,systolic blood pressure,diastolic blood pressure,mean arterial pressure,PP,prevalence of diabetes mellitus,proportion of beta-blocker,angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and lipidlowering drugs application,were significantly different among four groups(P<0.05).There was statistical significance of total arterial compliance(TAC),systemic vascular resistance,effective arterial elastance(Ea)and end-systolic left ventricular elastance(Ees)among the four groups(P<0.05).Regardless of the status of PP,Ea and Ees in the aortic dilatation group were lower than those in the normal aorta group,while TAC was higher than that in the normal aorta group(P<0.05).At all age groups,LVMI increased in succession in the four groups,i.e.,the group with the normal aorta and lower PP,with the normal aorta and higher PP,with aortic dilatation and lower PP,and with aortic dilatation and higher PP(Ptrend<0.01).The prevalence of LVH in this study population was 10.2%,and the prevalence of LVH increased sequentially in the four groups.Compared to the group with the normal aorta and lower PP,individuals with aortic dilatation had a significantly increased multivariable-adjusted risk of LV hypertrophy,and higher PP further exacerbated this risk[OR for aortic dilatation with lower PP:1.75(95%CI 1.013.04),OR for aortic dilatation with higher PP:3.42(95%CI 2.03-5.77)].Ascending aortic diameter was negatively correlated with PP,and ascending aortic diameter,PP and LVMI were positively correlated(β=-0.132,0.274,0.131,P<0.001).In the relation between PP and LVMI(β=0.095,P<0.001),-41.3%of the total effect was attributable to mediation by aortic diameter(P<0.001).Conclusion:In elderly patients with hypertension,ascending aorta dilatation could reduce the influence of arterial pulsatile load on LV afterload.