Background To compare the clinical efficacy and safety of catheter-directed thrombolysis（CDT）with anticoagulation vs anticoagulation alone（AC）in patients with submassive pulmonary embolism（sPE）.
METHODS Included in this analysis were patients with submassive pulmonary embolism. Two researchers independently screened the literature, submitted the data and cross-checked them. In case of differences, the third researcher would assist to make the judgment. RevMan5.4 was used for Meta analysis. Odds ratio (OR) was used as outcome index for dichotomous variables, and weighted mean difference (WMD) was used as outcome index for continuous variables. Point valuation/95%CI was given for each indicator. With P > 0.05 and I2 < 0.5, the fixed effect model was used for Meta analysis. The primary outcomes were all-cause death at 30 days and 1 year. Secondary outcomes were total bleeding and major bleeding.
RESULTS A total of 7 articles and 874 patients were included in this study. 323 patients were in the CDT+AC group and 551 patients were in the AC group. 30 days and 1 year mortality were lower in the CDT+AC group compared to AC group [（OR：0.35，95%CI：0.14-0.88，P=0.03，I2=0%),（OR：0.36，95%CI：0.18-0.71，P=0.004，I2=0%）]. In subgroup analysis 30 days and 1 year mortality were lower in the USAT+AC group compared to AC group[（OR：0.28，95%CI：0.08-0.98，P=0.05，I2=0%),（OR：0.32，95%CI：0.11-0.95，P=0.04，I2=0%）]. The incidence of total bleeding was lower in AC group compared to CDT+AC/USAT+AC group. Major bleeding were similar between them.
Conclusion Results thus confirmed that CDT reduced 30-days and 1-year all-cause mortality in patients with sPE compared to anticoagulation alone (AC). Nonetheless, a higher risk of bleeding was associated with the CDT group.