Outcomes with treatment interventions for clot-in-transit in patients with pulmonary embolism: a meta-analysis

Objectives: Clot-in-transit (CIT) in patients with pulmonary embolism (PE) has been associated with a high mortality rate and poor prognosis. The aim of this study was to evaluate the pooled efficacy of each of the 4 interventions (anticoagulation [AC] alone, systemic thrombolytic [ST] therapy, surgical thrombectomy, and catheter-based thrombectomy [CBT]) using mortality as the primary outcome.

Methods: A time limited search until March 28, 2024 was conducted using PubMed (National Institutes of Health) and EMBASE (Elsevier) databases.

Results: Thirteen studies (6 retrospective, 4 non-randomized prospective, and 3 pooled studies of case-reports) were included in the calculation of weighted proportion of mortality, including a total of 492 patients with CIT and PE with a mean age of 60.6 years; 50.1% were males. ST was the most frequently used treatment intervention (38.2%), followed by surgical thrombectomy (33.8%), AC alone (22.6%), and CBT (5.9%). The unweighted mortality was highest with AC alone 32.4% (36/111), followed by surgical thrombectomy 23.2% (38/164), CBT 20.7% (6/29), and ST 13.8% (26/188). The weighted mortality for AC alone was 35% (95% CI, 21% to 49%; 12 studies), surgical thrombectomy was 31% (95% CI, 16% to 47%; 12 studies), CBT was 20% (95% CI, 6% to 34%; 3 studies), and ST was 12% (95% CI, 5% to 19%; 12 studies).

Conclusions: In this meta-analysis of patients with CIT and PE, the highest mortality was observed with AC alone, followed by surgical thrombectomy, CBT, and ST therapy. However, there remains a need for randomized clinical trial data to determine the best treatment.