Correlation Between Decreased Coronary Artery Compliance And Decreased Diastolic Function In Coronary Heart Disease

Background:Previous studies of left ventricular diastolic function(LVDF)have focused on the decrease in active and passive diastolic function due to ischemic factors but have not investigated if the decrease in compliance of the coronary arteries that bypass the surface of the heart and travel between the myocardium could cause a constricting effect on the ventricular wall like that caused by myocardial fibrosis.Objective:To investigate the effect of reduced compliance of the coronary arteries and their vascular network on left ventricular diastolic function in patients with coronary heart disease(CHD).Methods:The 581 patients selected were divided into four groups according to the degree of coronary artery stenosis.Group A patients were the control group.Group B patients had less than 50%coronary artery stenosis.Group C patients had a coronary stenosis between 50%and 75%.Group D patients had a coronary stenosis greater than 75%.According to the number of stents,there were 192 cases in the single-stent group and 126 cases in the multi-stent group;according to the site of stent implantation,the single-stent group was divided into 129 cases of LAD,29 cases of LCX and 34 cases of RCA;according to the length of the implanted stents,the single-stent group was divided into 93 cases in Group Ⅰ(stent length ≤ 24 mm),91 cases in Group Ⅱ(24 mm<stent length ≤ 36 mm)and 8 cases in Group Ⅲ(36 mm<stent length).length)in 8 cases.The diastolic function of the ventricle was reflected by the relaxation time constant T value,which is the time between peak dp/dt and end-diastolic pressure in the left ventricle.All patients came in for a repeat CAG 9 months—1 year after stenting to collect indicators reflecting cardiac volumes,size and left ventricular systolic and diastolic function.Results:Patients in the control group were selected and grouped at 10-year age intervals.Statistically significant T values were found for patients in different age groups,with an increase in T values for the corresponding diastolic function indexes as the age of the patients increased.A one-way ANOVA yielded statistically significant differences in Gensini scores between patients in groups B,C and D(p<0.001);a correlation analysis with T as the dependent variable for patients in group D showed a correlation between T and Gensini scores and C-dp/dtmax(Pearson R=0.696,-0.540,p<0.001).Pre-and post-PCI coronary CT,left ventricular pressure curves and coronary pressure curves showed a decrease in diastolic function in the short postoperative period;T values before and after stenting in LAD were found to be more variable than LCX and RCA according to the site of stenting and the number of stents implanted(p<0.001),and T values before stenting,immediately after stenting and 1 year after stenting in patients with LAD showed a greater change in T values in the immediate postoperative period.T values before stenting,immediately after stenting and 1 year after stenting in LAD patients showed deterioration in diastolic function in the immediate postoperative period,but not in LCX and RCA patients;by grouping stent length,a correlation was found between T and stent length in LAD patients(Pearson R=0.437,P<0.01),while the correlation between T and stent length in LCX and RCA patients was not statistically significant(LCX:Pearson R=0.206,P=0.283,RCA:Pearson R=0.246,P=0.160).After grouping T values in the LAD single stent,LAD double stent and LAD triple stent groups according to the upper limit of normal T values,ROC curves were plotted and the optimal cut-off value for stent length was determined to be 24.5 mm area under the curve 0.844,CI:0.747-0.942,p<0.001).Conclusions:The degree of coronary atherosclerosis,the length of stent implantation and the resulting decrease in coronary vascular network compliance were positively correlated with the degree of decrease in left ventricular diastolic function in patients with CHD,and stent implantation caused an immediate decrease in diastolic function in patients with PCI,but the improvement in diastolic function after 1 year was greater than the immediate decrease,suggesting that the coronary arteries that bypass the surface of the heart and travel between the myocardium The decrease in compliance creates a "binding effect" on the ventricular wall similar to that created by myocardial fibrosis.