Pulmonary embolism: no clear role for thrombolysis with tPA.

Clinical bottom line (level 1b-)

  1. In patients with pulmonary embolism, there was no significant decrease in vessel occlusion as seen on angiogram before or after treatment using tissue plasminogen activator or placebo.
  2. There was no clear difference in bleeding.
The PIOPED Investigators : Chest 1990; 97 (3): 528-533
Expires October 2003

The study

Double-blinded concealed randomised trial with intention-to-treat
Setting: six tertiary referral centres, USA

13 patients (aged range 20 to 78 years, 69% male) symptoms of pulmonary embolism, confirmed by angiogram (occlusion of lobar artery or at least two segmental arteries.)

Excluded if
  • CPR within two weeks
  • uncontrolled shock
  • shock, major disability due to PE
  • uncontrolled hypertension
  • bleeding problem: eg. GI bleed in last six months, bleeding disorder
  • history of cerebrovascular accident
  • severe trauma in last two months, surgery in last ten days
  • renal or hepatic dysfunction
  • pregnant
  • psychologic or physical inability to participate
  • previous participation in PIOPED tPA trial


    • Control Group: (n = 4, 4 analysed): placebo +/- heparin
    Experimental Group: (n = 9, 9 analysed): heparin and tissue plasminogen activator at 40, 64 or 80 mg
    Patients had pulmonary angiogram before treatment and two hours later. Interpreted by blinded radiologist using scoring system.
    100% followed for 2 hours

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    bleed 2 hours 0
    (0.0%)    		 1
    (11.1%)    		 .%
    (% to %)    		 -11.1%
    (-31.6% to 9.42%)    		 -9
    (NNT = 11 to infinity;
    NNH = 3 to infinity)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    decrease in occlusion score: left lung 0.1
    ()     		-0.3
    ()     		NS
    ( to )
    decrease in occlusion score: right lung -2.5
    ()     		1.8
    ()     		NS
    ( to )

    Comments

    1. This is a very small study using secondary endpoints with short follow-up. It is not large enough to show any small benefit or harm from thrombolysis.

    Citation

    1. The PIOPED Investigators , : tissue plasminogen activator for the treatment of acute pulmonary embolism: a collaborative study by PIOPED investigators. Chest 1990; 97 (3): 528-533
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer:

    Clinical Question.
    Patient pulmonary embolism
    Intervention or Exposure tPA
    Comparison placebo
    Outcome vessel occlusion, bleeding