LUNG-SCAN EVALUATION OF THROMBOLYTIC THERAPY FOR PULMONARY-EMBOLISM

Data from three trials of thrombolytic therapy for pulmonary embolism (PE) were combined to assess the utility of perfusion lung scan defect scoring in predicting the response to thrombolytic therapy. Methods: Pre- and post-therapy lung scans and duration of symptoms were availab le for a total of 221 patients, 167 were treated with various thrombol ytic regimes and 54 were treated with heparin alone. Results: Improvem ent in the lung scan defect score was correlated with larger initial d efect score (r = 0.53), segmental appearance (r = 0.31) and shorter du ration of symptoms (r = 0.20). There was no significant residual corre lation between improvement and segmental appearance in a multiple regr ession analysis after accounting for initial defect score and duration of symptoms. Two lung scan scoring methods (segmental and anterior-po sterior method) provided similar results with low interobserver variab ility (r = 0.90 for both methods). Conclusion: This study indicates th at the baseline perfusion lung scan defect severity helps to predict t he response to thrombolytic therapy.