RISK OF FATAL PULMONARY-EMBOLISM IN PATIENTS WITH TREATED VENOUS THROMBOEMBOLISM

Context.-The most serious complication of deep vein thrombosis (DVT) o r nonfatal pulmonary embolism (PE) is fatal PE, However, reliable esti mates as to the risk of fatal PE in patients with treated DVT or PE ar e lacking. Objective.-To provide reliable estimates of the risk of fat al PE and the case-fatality rate of recurrent DVT or PE among patients presenting with symptomatic DVT or PE, during and following 3 months of anticoagulant therapy. Data Sources.-A MEDLINE literature search wa s performed to identify prospective studies in which patients with sym ptomatic DVT or PE were treated with 5 to 10 days of heparin and 3 mon ths of oral anticoagulants. We searched the years 1966 to September 19 97 using the search terms thrombophlebitis, diagnosis, drug therapy, a nd prognosis. Current Contents and bibliographies were also scanned. D ata Extraction.-Of 137 retrieved studies, 25 studies satisfied predete rmined methodologic criteria and were included in the analysis. Data S ynthesis.-Among patients presenting with DVT, the rate of fatal PE dur ing anticoagulant therapy was 0.4% (95% confidence interval [CI], 0.2% -0.6%); following anticoagulant therapy it was 0.3 per 100 patient-yea rs (95% CI, 0.1-0.8). The case-fatality rate of recurrent DVT or PE du ring anticoagulant therapy was 8.8% (95% CI, 5.0%-14.1%); following an ticoagulant therapy it was 5.1% (95% CI, 1.4%-12.5%), Among patients p resenting with PE, the rate of fatal PE during anticoagulant therapy w as 1.5% (95% CI, 0.9%-2.2%); following anticoagulant therapy it was 0 per 265 patient-years (95% CI, 0-3.6), The case-fatality rate of recur rent DVT or PE among patients presenting with PE was 26.4% (95% CI, 16 .7%-38.1%). Conclusion.-Among patients with symptomatic PE or DVT who are treated with anticoagulants for 3 months, fatal PE is rare during and following anticoagulant therapy. Patients presenting with PE are m ore likely to die of recurrent PE or DVT than are patients presenting with DVT.