Background: The optimal duration of anticoagulant therapy after a first unprovoked venous thromboembolism (VTE) is controversial due to tightly balanced risks and benefits of indefinite anticoagulation for secondary prevention of recurrence. A better assessment of the risk of recurrence after a first VTE event following discontinuation of anticoagulation is necessary to determine the optimal, individualized management strategy.
Aims: To assess the association between residual pulmonary vascular obstruction (RPVO) on planar lung scan and recurrent VTE at one year in patients with a first acute pulmonary embolism (PE) who discontinued anticoagulant therapy following an initial treatment of ≥ 3 months.
Methods: Study selection: Prospective cohort studies and randomised controlled trials in patients who experienced a first episode of objectively confirmed acute PE, completed at least 3 months of anticoagulant therapy and did not have any recurrence during this period.
Datasources: MEDLINE, EMBASE, and the Cochrane Central Registry of Controlled Trials.
Results: Four studies were identified, individual data obtained for all 809 patients. RPVO (i.e. obstruction>0%) was found in 407 patients (50.3%) after a median of 6.6 months of treatment. Recurrent VTE or death due to PE occurred in 114 patients (14.1%) for an annual risk of 6.4% (95% CI 4.7%-8.6%). Out of the 114 recurrences, 63 occurred within one year after discontinuation of anticoagulant therapy corresponding to a risk of 8.1% (6.4%,9.8%) at 1 year. Recurrent VTE occurred in 50 of 483 (10.4%, 95%CI 6.7%-15.7%) participants with RPVO < 5%, and in 64 of 326 (19.6%, 95%CI 13.5%-27.6%) participants with RPVO≥5%: hazard ratio 2.08 (95%CI 1.82-2.38).
Conclusion(s): In this individual participant data meta-analysis, RPVO is a significant predictor of the risk of recurrent events. However, the risk of recurrent events remains too high in patients without residual perfusion defect for it to be used as a stand alone test to decide on anticoagulation discontinuation.
The association between RPVO and the risk of recurrence
Abbreviations: n: number; IQR: Interquartile range, CI: Confidence interval; RPVO: residual pulmonary vascular obstruction
To cite this abstract in AMA style:
Robin P, Le Pennec R, Eddy M, Sikora L, Le Roux P, Carrier M, Couturaud F, Tromeur C, Planquette B, Sanchez O, Pesavento R, Rodger M, Kovacs M, Mallick R, Salaun P, Le Gal G. Residual pulmonary vascular obstruction and recurrence after acute pulmonary embolism: a systematic review and meta-analysis of individual participant data [abstract]. https://abstracts.isth.org/abstract/residual-pulmonary-vascular-obstruction-and-recurrence-after-acute-pulmonary-embolism-a-systematic-review-and-meta-analysis-of-individual-participant-data/. Accessed August 16, 2022.« Back to ISTH 2022 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/residual-pulmonary-vascular-obstruction-and-recurrence-after-acute-pulmonary-embolism-a-systematic-review-and-meta-analysis-of-individual-participant-data/