title: Thrombolysis vs heparin in the treatment of pulmonary embolism: a clinical outcome-based meta-analysis.
abstract: BACKGROUND
  In patients with acute pulmonary embolism, thrombolysis results in a more rapid resolution of pulmonary emboli than heparin treatment. Whether this advantage results in an improved clinical outcome is unclear. We sought to perform a clinical outcome-based meta-analysis of studies comparing thrombolytic and heparin treatment in patients with pulmonary embolism.
  
  
  METHODS
  Data concerning adverse outcome events (death, recurrent pulmonary embolism, and major bleeding events) were extracted from the identified randomized studies.
  
  
  RESULTS
  A total of 56 (23.2%) of 241 patients treated with thrombolytic agents in 9 randomized trials experienced an adverse outcome event compared with 57 (25.9%) of 220 patients treated with heparin (relative risk [RR], 0.9; 95% confidence interval [CI], 0.57-1.32). In the thrombolysis group, 11 patients (4.6%) died compared with 17 (7.7%) in the heparin group (RR, 0.59; 95% CI, 0.27-1.25). Thirty-one patients (12.9%) undergoing thrombolysis had a major bleeding episode compared with 19 patients (8.6%) treated with heparin (RR, 1.49; 95% CI, 0.85-2.81). Five fatal bleeding episodes (2.1%) occurred in the thrombolysis group and none in the heparin group. Six studies provided data on recurrent pulmonary embolism. A recurrence occurred in 14 (6.6%) of 214 patients treated with thrombolytic agents and in 22 (10.9%) of 201 patients treated with heparin (RR, 0.60; 95% CI, 0.29-1.15). Recurrence and/or death occurred in 25 (10.4%) of 241 and in 38 (17.3%) of 220 patients treated with thrombolytic agents and heparin, respectively (RR, 0.55; 95% CI, 0.33-0.96; P =.03).
  
  
  CONCLUSIONS
  In patients with pulmonary embolism, thrombolysis had a lower composite end point of death/recurrence than heparin treatment. Excessive bleeding is the trade-off for improved efficacy. A comparative clinical outcome trial of thrombolysis and heparin treatment is warranted in patients with pulmonary embolism and selected for high risk of death and/or recurrence and low risk of bleeding.
authors.affiliation: Sezione di Medicina Interna e Cardiovascolare, Dipartimento di Medicina Interna, Università degli Studi di Perugia, Via Enrico dal Pozzo, I-06123 Perugia, Italy. agnellig@unipg.it
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Agnelli
authors.forename: Cecilia
authors.initials: C
authors.lastname: Becattini
authors.forename: Timo
authors.initials: T
authors.lastname: Kirschstein
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D016001:Confidence Intervals; D005260:Female; D006493:Heparin / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D008297:Male; D016017:Odds Ratio; D011379:Prognosis; D011655:Pulmonary Embolism / Q000188:drug therapy* / Q000401:mortality*; D016032:Randomized Controlled Trials as Topic; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis; D015912:Thrombolytic Therapy / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D006493:Heparin