Thrombus Obliteration by Rapid Percutaneous Endovenous Intervention in Deep Venous Occlusion - TORPEDO

Description:

The current trial sought to study whether percutaneous endovenous intervention (PEVI) in addition to anticoagulation would be associated with superior outcomes in patients with acute symptomatic lower extremity deep venous thromboses (DVTs), as compared with anticoagulation alone.

Hypothesis:

PEVI in addition to anticoagulation would be superior to anticoagulation alone in patients with acute symptomatic lower extremity DVTs.

Study Design

  • Randomized
  • Parallel

Patient Populations:

  • Acute symptomatic proximal DVT

    Number of enrollees: 183
    Duration of follow-up: 30 months
    Mean patient age: 61 years
    Percentage female: 48%

Primary Endpoints:

  • Development of PTS
  • Recurrent venous thromboembolic disease

Secondary Endpoints:

  • Skin induration
  • Leg edema
  • Hospital length of stay
  • Subjective perception of improvement
  • Bleeding

Drug/Procedures Used:

Patients in the anticoagulation arm received unfractionated heparin (UFH) 80 U/kg as a bolus, followed by 18 U/kg/hr, to maintain an activated partial thromboplastin time (aPTT) of 1.5-2 x normal. Enoxaparin at a dose of 1 mg/kg subcutaneously twice daily could also be used in lieu of UFH. All patients received Coumadin as well. In general, a parenteral regimen was instituted for 5 days, with an overlap of 24 hours with Coumadin. All patients also received compression stockings at 30-40 mm Hg.

Patients in the PEVI arm received all the measures above, except that parenteral therapy for a full 5 days was not necessary. They were taken for PEVI within 24 hours. A popliteal approach was favored. PEVI consisted of a number of measures such as AngioJet, Trellis, balloon venoplasty, stenting, manual aspiration, and catheter-directed thrombolysis. All PEVI patients also received inferior vena cava (IVC) filters.

Concomitant Medications:

Patients in the PEVI arm received aspirin 81-325 mg.

Principal Findings:

A total of 183 patients were randomized, 91 to PEVI and 92 to control, of which 8 crossed over to the PEVI arm. Baseline characteristics were fairly similar between the two arms. About 35% of the patients had concomitant cardiovascular disease. About 13% of the patients had undergone surgery or trauma in the past 3 months, 6% were on estrogen therapy, 15% had current or history of cancer, 4% had known prothrombotic state, and 17% had prior venous thromboembolic disease (VTE). Concomitant pulmonary embolism (PE) was noted in 22% of the patients, and 23% had DVT at another site as well.

The primary endpoint of post-thrombotic syndrome (PTS) was lower in the PEVI arm, as compared with the anticoagulation arm (6.8% vs. 29.6%, p < 0.001), mostly due to a reduction in mild PTS (4.5% vs. 18.5%, p = 0.007). Total VTE was also lower in the PEVI arm (4.5% vs. 16%, p = 0.02). Recurrent DVT (4.5% vs. 11.1%, p = 0.15) and nonfatal PE (0% vs. 3.7%, p = 0.11) were similar between the two arms. Secondary endpoints such as hospital stay (2.7 vs. 5.8 days, p < 0.001), and change in skin induration (10 mm vs. 3 mm, p < 0.001) were also better in the PEVI arm.

Interpretation:

The results of this small trial indicate that PEVI using a number of measures such as AngioJet, Trellis, and stenting, in addition to anticoagulation, is associated with a reduction in PTS and recurrent VTE in patients with acute symptomatic lower extremity DVT. A number of caveats exist. The definition of PTS was nonstandardized, and the maximal improvement was in the mild PTS category.

Further, all patients receiving PEVI also received IVC filters. Thus, although recurrent VTEs were lower in the PEVI arm, it is unclear how IVC filters influenced this outcome. Still, this is one of the first endovenous interventional trials. The results of the ongoing ATTRACT trial comparing catheter-directed thrombolysis to anticoagulation in this patient population are awaited.

References:

Presented by Dr. Mohsen Sharifi at the Transcatheter Cardiovascular Therapeutics Meeting (TCT 2010), Washington, DC, September 24, 2010.

Keywords: Vena Cava, Inferior, Follow-Up Studies, Vena Cava Filters, Stockings, Compression, Enoxaparin, Pulmonary Embolism, Partial Thromboplastin Time, Estrogens, Heparin, Postthrombotic Syndrome, Venous Thrombosis, Length of Stay


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