Recurrence ofpulmonary embolism during anticoagulant treatment: aprospective study

Therisk ofearly recurrenceofpulmonary embolism inpatients with venous throm- boembolic disease treated byanticoagulants isnotwell established. Todetermine therisk linked to contemporary proximal deep venousthrombosis, aprospective study was organised togive clinical andscintigraphic surveillance to50patients withangiographically proved pulmonary embolism plusphlebographically proved proximal deepveinthrombosis during thefirst 15daysofanti- coagulant treatment. Perfusion lung scanswereperformed initially andon days3,7,and15.Only twopatients hada recurrenceofpulmonary embolism during this period; bothepisodes were revealed bynew symptoms,andone recurrencewas fatal. Thesystematic performance ofangio- graphy infour patients found tohave new scintigraphic defects ledtothethediagnosis of"spurious scintigraphic recurrence" inthree ofthem. Itisconcluded that (a)adjusted anticoagulant treatment showed an effectiveness of96%forpreventing early recurrenceofpulmonary embolism inthis groupofsupposed highrisk patients, and(b)inpatients withrecentpulmonary embolism new defects on systematic perfusion lungscansarenotspecific indicators ofrecurrent pulmonary embolism.