Clinical study of inferior vena cava filter combined with catheter-directed thrombolysis in treating intermediate-risk pulmonary thromboembolism

To evaluate the clinical efficacy and safety of early inferior vena cava filter (IVCF) implantation combined with catheter-directed thrombolysis (CDT) in the management of intermediate-risk pulmonary thromboembolism (PTE). A total of 300 patients with acute intermediate-risk PTE, treated in Chongqing Seventh People's Hospital and the First Hospital Affiliated with Chongqing Medical College of Higher Education between January 10, 2023, and July 31, 2023, were included in the study. Participants were randomly assigned to either the control group (n=150) or the study group (n=150). The control group received anticoagulation therapy (ubcutaneous injection of low molecular weight heparin 100 IU/kg twice daily) +IVCF, while the study group received anticoagulation therapy +IVCF +CDT. The clinical outcomes and adverse events were compared between the two groups. Multiple linear regression analysis was performed to identify risk factors of thrombus clearance rates. During the treatment period, FIB levels in both groups exhibited a continuous decline (P<0.05), while D-D levels initially increased before decreasing (P<0.05). Meanwhile, the FIB and D-D levels in the study group were significantly lower than the control group (P<0.05). After 72 hours of treatment, the study group had lower HR, SBP, RR, and Miller score compared to the control group (P<0.05), while had higher SpO 2 (P<0.05). Blood gas analysis at 72 hours revealed significantly higher pH, PaCO 2 , and PaO 2 in the study group than in the control group (P<0.05). Besides, the study group had higher left ventricular ejection fraction (LVEF) and lower N-terminal pro B-type natriuretic peptide (NT-proBNP) than the control group (P<0.05). The study group exhibited significantly lower SPAP, right ventricular to left ventricular (RV/LV) ratio, and a significantly higher LVEF compared to the control group during treatment (P<0.05). A higher proportion of mild to moderate bleeding was observed in the study group compared to the control group (P<0.05), with no instances of severe or life-threatening bleeding. Additionally, multiple linear regression analysis (F=2007.89, R²=0.697) revealed that CAD, PESI score, D-D, SPAP, Miller score, and NT-proBNP were negatively correlated with thrombosis resolution (P<0.05), while SpO 2 and PaCO 2 showed a positive correlation (P<0.05). The combined use of IVCF and CDT can significantly improve hemodynamic abnormalities and effectively mitigate cardiac function of patients with PTE in the early stages, with acceptable safety.