Clinical Study On The Efficacy And Safety Of Rivaroxaban In The Treatment Of Left Ventricular Thrombosis

Background:Left ventricular thrombus（LVT）is a serious clinical complication,which mainly occurs in patients with acute anterior myocardial infarction and left ventricular ejection fraction less than 40%.In recent years,with the widespread development of percutaneous coronary intervention and the widespread application of reversing ventricular remodeling,powerful antithrombotic drugs,the incidence of this complication has gradually decreased.The clinical harm of left ventricular thrombus mainly lies in the loss of cardiogenic thrombus,which runs along the direction of arterial blood flow and leads to embolism of peripheral arteries and important organs（spleen,kidney and brain）,with a high incidence of disability and death.Early detection of left ventricular thrombosis and antithrombotic therapy can reduce the incidence of embolic events in target organs.The mechanism of thrombosis is still unclear,and current studies have shown that it is closely related to Virchow’s classical theory.Therefore,anticoagulant therapy is the cornerstone of treatment of left ventricular thrombosis from beginning to end.Based on expert consensus,traditional anticoagulant warfarin occupies a dominant position.However,due to its narrow safety window,underdosage or overdosage is common,which leads to the coexistence of high embolism and high blood risk,and low bioavailability,which reduces patients’ treatment compliance and limits its clinical application.With the deepening of research,new oral anticoagulant drugs have come into being gradually,among which rivaroxaban is an oral inhibitor of factor Ⅹa,which plays an anticoagulant effect mainly by directly inhibiting the free and bound factor Ⅹa in the coagulation process,blocking thrombin generation and stopping coagulation waterfall reaction.It has the advantages of rapid onset,predictable efficacy,no need for routine monitoring of coagulation indicators and adjustment of drug dose,and has potential myocardial protection and anti-inflammatory properties,so it has gained popularity in clinical practice.However,due to the limited evidence on prevention and treatment of left ventricular thrombosis in the current guidelines,most of which are from early clinical studies,there are still controversies on how to diagnose left ventricular thrombosis early,prevent left ventricular thrombosis and the most appropriate antithrombotic treatment strategies.Therefore,it is of great guiding significance to study the clinical efficacy and safety of rivaroxaban in the treatment of left ventricular thrombosis.Objective:This study aimed to investigate the clinical efficacy and safety of rivaroxaban in the treatment of left ventricular thrombosis.Methods:1.A total of 312 patients diagnosed with left ventricular thrombosis during hospitalization in the Department of Cardiology,The First Hospital of Jilin University from January 1,2014 to June 30,2021 were enrolled.Clinical data of all patients were collected and divided into rivaroxaban group（n=209）and warfarin group（n=103）,according to the types of oral anticoagulants.All patients were continuously observed and followed up for 3 months,between the two groups,the basic clinical data,the time of left ventricular thrombus disappearance,the number of cases that disappeared,bleeding events,new thromboembolism events and all-cause death events of patients were recorded and compared during the follow-up period.2.A total of 209 left ventricular thrombosis patients in the above rivaroxaban group were divided into low-dose group（n=92）and medium-high dose group（n=117）,according to the different oral rivaroxaban doses.Patients in the low-dose group received rivaroxaban 2.5 mg twice a day or rivaroxaban 10 mg orally,once a day,while patients in the medium-high dose group received rivaroxaban 15 mg or 20 mg orally,once a day.Between the two groups,the basic clinical data,the time of left ventricular thrombus disappearance,the number of cases that disappeared,bleeding events,new thromboembolism events and all-cause death events of patients were recorded and compared during 3-month follow-up Results:1.There were no statistically significant differences between the rivaroxaban group and warfarin group in age,gender,smoking history,accompanying underlying diseases,left ventricular ejection fraction,left ventricular end-diastolic diameter,thrombosis,creatinine clearance rate and combined antiplatelet drugs（P > 0.05）.2.Comparison of clinical efficacy between the rivaroxaban group and warfarin group: the time of left ventricular thrombus disappearance in the rivaroxaban group was significantly lower than that in the warfarin group during the 3-month follow-up period[（65.35±13.07）d vs（70.79±11.29）d,P=0.004],and the difference was statistically significant.The rivaroxaban group had a higher rate of left ventricular thrombus disappearance during the 3-month follow-up period than the warfarin group（70.3% vs64.1%,P=0.264）,but the difference was not statistically significant.3.Comparison of safety between the rivaroxaban group and warfarin group:during 3-month follow-up,the incidence of thromboembolic events（3.3% vs 5.8%）,bleeding events（3.3% vs 6.8%）and all-cause mortality（1.0% vs 3.9%）in the rivaroxaban group were lower than those in the warfarin group,but the differences were not statistically significant（all P > 0.05）.4.There were no statistically significant differences between the rivaroxaban low-dose group and medium-high dose group in age,gender,smoking history,accompanying underlying diseases,left ventricular ejection fraction,left ventricular end-diastolic diameter,thrombosis,creatinine clearance rate and combined antiplatelet drugs（P > 0.05）.5.Comparison of clinical efficacy between the rivaroxaban low-dose group and medium-high dose group: compared with the low-dose group,the time of left ventricular thrombus disappearance in the medium-high dose group was significantly shorter during 3-month follow-up [（61.46±12.58）d vs（71.33±11.53）d,P < 0.001],and the difference was statistically significant.The rate of left ventricular thrombus disappearance in the medium-high dose group was significantly higher than that in the low-dose group during the 3-month follow-up period（76.1% vs 63.0%,P=0.041）,and the difference was statistically significant.6.Comparison of safety between the rivaroxaban low-dose group and mediumhigh dose group: during 3-month follow-up,there were no statistically significant differences in new thromboembolic events（4.3% vs 2.6%）,bleeding events（2.2% vs4.3%）and all-cause deaths（1.1% vs 0.9%）between the two groups（all P > 0.05）.Conclusion:1.Compared with warfarin,rivaroxaban does not increase the risk of thromboembolism,bleeding and all-cause death in patients of left ventricular thrombosis,and is safer and more effective for the treatment of left ventricular thrombosis.In addition,rivaroxaban has more advantages in the intensity and speed of left ventricular thrombus treatment,which is faster and stronger in inhibiting new thrombosis and promoting thrombolysis.2.Among the different dosage regiments of rivaroxaban,the regimen of rivaroxaban 15 mg or 20 mg orally（once per day）has good safety data,moreover,it can promote the dissolution of thrombus more quickly and more strongly,which is better for the treatment of left ventricular thrombosis.