Meta-Analysis Comparing Catheter-Directed Thrombolysis Versus Systemic Anticoagulation Alone for Submassive Pulmonary Embolism.

Ismayl M, Machanahalli Balakrishna A, Aboeata A, Gupta T, Young MN, Altin SE, Aronow HD, Goldsweig AM.

Am J Cardiol. 2022 Sep 1;178:154-162. doi: 10.1016/j.amjcard.2022.06.004. Epub 2022 Jun 29. PMID: 35778309.

Aim of Study

Assess evidence for mortality benefit of catheter directed thrombolysis (CDT) vs systemic anticoagulation in submassive pulmonary embolism (sPE)

Design

Meta-analysis

Methodology

11 observational studies and 1 RCT included in meta-analysis

1871 patients who received CDT vs 7918 who received systemic anticoagulation

Primary Outcome

All-cause 30-day, 90-day and 1-year mortality

Secondary Outcomes

Major and minor bleeding, blood transfusion, RV recovery and hospital length of stay

Results

Majority of patients included were over 50 years old

Reasonably well matched between each intervention group in terms of gender and comorbidities

CDT compared to systemic anticoagulation was associated with statistically significant reduction in:

• In-hospital mortality (RR 0.41, p<0.001)
• 30-day mortality (RR 0.37, p = 0.004)
• 90-day mortality (RR 0.36, p = 0.004)

Tendency towards lower 1-year mortality, though not statistically significant (RR 0.56, p = 0.07)

• Same for RV recovery (RR 1.34, p = 0.07)

No statistically significant differences between the two groups in major or minor bleeding, blood transfusion and hospital length of stay

Analysis

Strengths:

• Representative and reasonably well-matched patient groups
• Large sample size with multiple studies included

Limitations:

• Majority of the studies included are observational leading to selection bias and unmeasured bias
• No standardisation of ‘systemic anticoagulation’ or patient setting in this arm
• Any limitations of the included original studies
• USCDT and CDT included with no subgroup analysis

Conclusions

Previous single studies and one previous meta-analysis failed to show such convincing mortality benefit of CDT

This large study has more power to highlight what may be a small magnitude difference in outcomes

Supports the expanding evidence for CDT as first line therapy for sPE

Should we be pushing for this in this patient population from our tertiary centres based on these results?

 

Discussion from Journal Club Meeting (?Change of Practice)

• Selection bias in terms of tertiary centres accepting patients for CDT
• Lack of standardisation within intervention groups limits interpretation
• Useful study for our discussions with tertiary centres
• Cost analysis would be helpful – CDT more costly as an intervention but ?long term population health cost benefit (better RV recovery, pHTN + RVF in the long term?)

Summary by Dr S Brockbank. Journal Club Meeting 1 June 2023.