SOLACI | Latin American Society of Interventional Cardiology

In recent times, pulmonary thromboembolism (PTE) has been the subject of growing research due to its persistent impact on morbidity and mortality. Acute PTE, if not properly treated or inadequately treated, can lead to a debilitating condition known as post-PTE syndrome, which has been documented in nearly 50% of survivors.

Tromboembolismo de pulmón agudo: cuando no todo es anticoagulación

The primary treatment strategy for these patients has been anticoagulation. However, in certain specific cases of intermediate-to-high-risk PTE, consideration should be given to more invasive approaches, as determined by interdisciplinary, prompt pulmonary embolism response teams (PERT). This same approach is applicable to high-risk patients who are not candidates for systemic thrombolysis (ST).

Given the limitations observed with anticoagulation alone or systemic thrombolysis, there has been a growing interest in catheter-directed thrombolysis therapy (CDT). Experts hope that it will provide similar efficacy in thrombus resolution but with an improved safety profile.

The available evidence is primarily based on observational studies and some single-arm or surrogate outcome randomized trials. In response to this situation, Zhang et al. conducted a network meta-analysis to compare the efficacy and safety of anticoagulation alone (AC), catheter-directed thrombolysis therapy (CDT), and systemic thrombolysis (ST) in patients with acute PTE.

This meta-analysis included 45 studies (17 randomized trials, 2 non-randomized prospective trials, and 26 retrospective observational trials) with a total of 81,705 patients. Of these, 19,976 were treated with AC, 9160 underwent CDT, and 52,119 received ST. There was an approximately equal proportion of men (48.6%) and women, with an average age ranging from 46.9 to 75.3 years. Most of the included patients had intermediate-risk PTE.

Efficacy was assessed through an analysis of all-cause mortality. Compared with AC alone, CDT was significantly associated with a lower risk of mortality (odds ratio [OR]: 0.55; 95% confidence interval [CI]: 0.39-0.80), but ST did not show such an association (OR: 1.14; 95% CI: 0.76-1.70). In the comparison between CDT and ST, the ST group had a higher risk of mortality (OR: 2.05; 95% CI: 1.46-2.89), although this result was accompanied by significant inconsistency (P≤0.036).

The safety profile was assessed through the analysis of severe bleeding events. Both CDT (OR: 1.84; 95% CI: 1.10-3.08) and ST (OR: 2.16; 95% CI: 1.10-3.08) were associated with a higher risk of bleeding compared with AC alone. As for intracranial bleeding, CDT was associated with a higher risk of this type of bleeding compared with AC (OR: 1.51; 95% CI: 0.75-3.04).

Conclusions

While study inclusion seems to be somewhat heterogeneous and inconsistent, this meta-analysis highlighted some key points to consider. Patients treated with CDT shower a significant reduction in all-cause mortality compared with those treated with AC, unlike ST. However, this benefit was tempered by a higher risk of bleeding, including a higher number of intracranial hemorrhages, which remained lower than with ST.

Dr. Omar Tupayachi.
Member of the Editorial Board of SOLACI.org.

Original Title: Efficacy and Safety of Anticoagulation, Catheter-Directed Thrombolysis, or Systemic Thrombolysis in Acute Pulmonary Embolism.

Reference: Zhang, Robert S et al. “Efficacy and Safety of Anticoagulation, Catheter-Directed Thrombolysis, or Systemic Thrombolysis in Acute Pulmonary Embolism.” JACC. Cardiovascular interventions, S1936-8798(23)01263-3. 27 Sep. 2023, doi:10.1016/j.jcin.2023.07.042.