Deep vein thrombosis: tPA led to clot lysis but caused complications

Clinical bottom line (level 1a)

  1. Patients with lower-limb deep vein thrombosis who received rt-PA and heparin compared with heparin alone were more likely to have clot lysis (NNT = 4 at days) but also more likely to have complications (NNH = 5 at days) .
Forster and Wells: Chest 221; 119 : 572-579
Expires May 2004

The study

Systematic review of all randomised controlled trials of
  • Patients: lower-limb deep vein thrombosis
  • Intervention: systemic rt-PA and rt-PA and heparin compared with v. heparin; or low-dose rt-PA; or local rt-PA
  • Outcome: thrombus lysis, major haemorrhage

Articles found in ?English only using Medline and Current Contents, 1966 to September 1999 (search terms: detailed in text ) and contacting authors of identified RCTs and relevant pharmaceutical companies. Bibliographies of retrieved articles were also checked.

Selection criteria: by 1 reviewer
Appraisal criteria: by 2 reviewers: using Jadad criteria
Articles excluded if:
  • upper limb DVT
  • Jadad score < 3
5 RCTs found
  • 3 compared rt-PA and heparin with heparin alone involving 169 patients
  • 1 compared systemic rt-PA with local rt-PA involving 151 patients
  • 1 compared 2 doses of rt-PA involving 32 patients

The evidence

Outcome Time to outcome CER OR
(95% CI)		 NNT
(95% CI)
> 50% clot lysis days 2/54
(3.7%)		 11.7
(2.61 to 52.5) 		4
(2 to 18)
adverse events days 2/61
(3.3%)		 9.95
(2.21 to 44.7) 		-5
(-27 to -2)

  • High dose rt-PA was not clearly more effective than low-dose rt-PA.
  • Local rt-PA was not clearly more effective or safer than systemic rt-PA.

Comments

  1. There were significant differences in enrollment criteria and drug administration between the studies.
  2. Clot lysis is not an outcome that matters to patients. No study reported longterm effects on death, recurrent venous thromboembolism or chronic venous insufficiency.

Citation

  1. Forster A, and Wells P: tissue plasminogen activator for the treatment of deep vein thrombosis of the lower extremity: a systematic review. Chest 221; 119 : 572-579
Search Terms:
Contributor: Chris Ball, May 2002
Reviewer:

Clinical Question.
Patient lower-limb DVT
Intervention or Exposure rt-PA, alteplase
Outcome clot lysis, complications