Evaluation Of The Effect Of PD-1 Inhibitors On Cardiac Function In Tumor Patients By Two-dimensional Speckle Tracking Imaging Combined With Real-time Three-dimensional Echocardiography

【Background】With the progress of cancer treatment and the increase in the number of long-term cancer survivors,cardiovascular complications associated with cancer treatment have increasingly become an important health problem.Immunotherapy represents a great leap forward in the treatment of cancer,of which PD-1 inhibitors are the most representative.Although few cases of autoimmune cardiotoxicity and myocarditis have been reported in clinical trials,with the more widespread use of PD-1 inhibitors in recent years,the number of cases of severe cardiotoxicity caused by immunotherapy has increased significantly.Therefore,early identification of cardiotoxicity is of great significance to improve the prognosis and quality of life of tumor patients.Echocardiography is the first choice to determine the degree of left ventricular dysfunction and monitor the changes of cardiac function over time,and it has been widely used to monitor cardiotoxicity.Left ventricular ejection fraction（LVEF）is the most commonly used cardiac function index to monitor cardiotoxicity,but it has been replaced by two-dimensional speckle tracking technique（2D-STI）because of its lack of sensitivity in monitoring early cardiac injury.It plays an important role in the evaluation of myocardial ischemia,ventricular wall motion asynchrony,cardiac dysfunction and other heart diseases,especially the two-dimensional strain parameter Left ventricular global longitudinal strain（LV GLS）.Real-time three-dimensional echocardiography（RT-3DE）is the latest development of cardiac echocardiography,which can directly evaluate the cardiac cavity without geometric assumptions,and prevent errors caused by section shortening,so as to measure cardiac function more accurately and repeatedly.The purpose of this study is to use two-dimensional speckle tracking technique combined with real-time three-dimensional echocardiography to monitor the changes of cardiac function in tumor patients before and after chemotherapy with PD-1 inhibitors.【Methods】A total of 52 patients with tumors treated with PD-1 inhibitors in our oncology department from April 2019 to December 2020 were examined by echocardiography before chemotherapy,after 2 cycles of chemotherapy,after 4 cycles of chemotherapy and within 24 hours after 6 cycles of chemotherapy.Left ventricular global longitudinal strain（LV GLS）and right ventricular global longitudinal strain（RV GLS）were obtained by 2D-STI.Left ventricular end-diastolic volume（3D-LVEDV）,left ventricular end-systolic volume（3D-LVESV）and left ventricular ejection fraction（3D-LVEF）were measured by RT-3DE.The left atrial volume index（LAVI）and right ventricular fractional area（FAC）was measured by two-dimensional echocardiography.Left ventricular end-diastolic volume（LVEDV）,left ventricular end-systolic volume（LVESV）and left ventricular ejection fraction（LVEF）were measured by Simpson method.Tricuspid annulus plane systolic excursion（TAPSE）was measured by M-mode echocardiography.Pulse Doppler measurement of the peak E-velocity of the mitral valve during early diastole and the peak A-velocity of the late diastole to calculate the E/A ratio.Tissue Doppler measurement of peak velocity of mitral annulus ventricular septal movement in early diastole e’,calculated E/e’.The results obtained were statistically analyzed.【Results】Compared with the baseline level,LVEF,3D-LVEF,e’,E/e’,RV GLS and TAPSE all showed significant difference from the end of the sixth cycle of chemotherapy（T₆）（P<0.05）.LVGLS,LVEDV,LVESV,3D-LVEDV and 3D-LVESV increased significantly from the end of the fourth cycle of chemotherapy（T₄）（P<0.05）.However,there was no significant difference in LAVI,E and E/A,which also reflected left ventricular diastolic function.There was no significant change in FAC reflecting the systolic function of the right ventricle（P>0.05）.There was a positive correlation between LV GLS and LVEF（simpson’s method）（r=0.726,P<0.01）,and between LV GLS and LVEF（3D）（r=0.753,P<0.01）.【Conclusion】Cardiotoxicity caused by PD-1 inhibitors can damage not only the left ventricle but also the right ventricle.GLS monitoring of cardiotoxicity of PD-1 inhibitors is more sensitive and accurate than conventional echocardiography,and can detect subclinical cardiac dysfunction earlier.PD-1 not only damages the left ventricular systolic function,but also damages the left ventricular diastolic function.