Evaluation Of Left Ventricular Function After Percutaneous Coronary Intervention Of Chronic Coronary Occlusions By Two-dimensional Speckle Tracking Echocardiography

Objective: Using two-dimensional speckle tracking echocardiography(2D-STE)to evaluate the changes of global and regional left ventricular myocardial function after percutaneous coronary intervention(PCI)in patients with chronic total occlusion(CTO),and to explore the value of speckle tracking technology in evaluating the effect of CTO-PCI.Methods: According to the inclusion and exclusion criteria,a total of 56 patients with CTO lesions who were successfully treated with PCI at Zhongda Hospital from October 2018 to October 2019 were enrolled.Routine echocardiography and two-dimensional speckle ultrasound imaging were performed before,1 month,and 3 months after PCI revascularization to obtain conventional ultrasound parameters and myocardial strain parameters.Routine ultrasound parameters include left ventricular end-diastolic volume(LVEDV),left ventricular end-systolic volume(LVESV),left ventricular end-diastolic volume index(LVEDVi),left ventricular end-systolic volume index(LVESVi),left ventricular ejection fraction(LVEF),and wall motion score index(WMSI).Echo PAC workstation was used to analyze the global and regional strain of left ventricle.Global strain indicators include: apical four-chamber global longitudinal peak systolic strain(GLPS-4AC),apical long-axis global longitudinal peak systolic strain(GLPS-LAX),apical two-chamber global longitudinal peak systolic strain(GLPS-2AC)and average global longitudinal peak systolic strain(GLPS-Avg).Based on the myocardial segments supplied by the coronary arteries,the regional longitudinal peak systolic strain(RLPS)of LAD,LCX and RCA perfusion regions were calculated.Conventional ultrasound parameters,global longitudinal strain,and corresponding RLPS of coronary arteries at pre-PCI and post-PCI were calculated and compared respectively.Patients were divided into good collateral circulation group and poor collateral circulation group according to Rentrop method.The changes of global longitudinal strain and regional longitudinal strain of patients in each group before and after PCI were observed.The strain parameters between the two groups at different time were compared and the interaction between time and collateral group were analyzed.Results: At 1 month after PCI,LVEF,LVEDV,LVEDVi and WMSI were not statistically different from those before PCI.LVEF,LVESV,LVEDV,LVESVi,LVEDVi and WMSI at 3 months after PCI were significantly different from those before and 1 month after PCI(P<0.001),which was statistically significant.Comparing pre-PCI and post-PCI,and comparing different period of postPCI,both the absolute value of global strain and regional strain in coronary perfusion area were significantly increased(P < 0.05),and the difference was statistically significant.There were significant differences in GLPS-Avg and RLPS between the good collateral circulation group and the poor collateral circulation group before surgery,1 month after surgery,and 3 months after surgery(P<0.001).The pairwise comparisons at each measurement time point were statistically significant(P<0.001),and the absolute values of GLPS-Avg and RLPS of the two groups of patients after PCI were significantly increased.There was no statistically significant difference in GLPS-Avg between the two groups at each measurement time point(P>0.05).The absolute value of RLPS in the good collateral circulation group at 1 month and 3 months after surgery was significantly higher than that in the poor collateral circulation group(P<0.05).There is an interaction between the formation of collateral circulation and time(P<0.05).After revascularization treatment,the absolute value of GLPS-Avg and RLPS in the good collateral circulation group increased more with time than in the poor collateral circulation group.Conclusion: PCI can significantly improve the global and regional left ventricular function in patients with CTO lesions.Compared with conventional ultrasound measurement methods,two-dimensional speckle tracking echocardiography can more sensitively and comprehensively reflect the recovery of global and regional myocardial motion capacity.It provides a non-invasive and convenient method for the evaluation of curative effect and prognosis of CTO interventional therapy.