Predictors of long-term clinical outcome of patients with acute massive pulmonary embolism after thrombolytic therapy

Abstract

Objective: To assess the in-hospital clinical course and the long-term evolution of acute massive pulmonary embolism after thrombolytic therapy and to identify predictors of adverse clinical outcome.

Methods: A total of 260 patients hospitalized from January 1989 to October 1998 were retrospectively reviewed and followed up for 3.9 to 8.4 years. Baseline characteristics and variables pre- and post-thrombolysis were identified. Particular attention was paid to the clinical events, including death, recurrent thromboembolism, chronic thromboembolic pulmonary hypertension, and major bleeding attributable to the use of anticoagulants. Kaplan-Meier event-free survival curves were generated. Univariate analysis by means of the log-rank test was used to test each candidate variable for association with clinical outcome. Multivariate analysis with the Cox proportional hazard model was used to determine independent predictors of the long-term outcome.

Results: The in-hospital mortality rate was 8.5%, with 68.2% due to pulmonary embolism itself, and the follow-up mortality rate was 31.7%, with 29.2% due to recurrent embolism. Factors associated with an adverse outcome in univariate analysis were: (1) prior thromboembolic diseases; (2) duration of anticoagulant therapy < 6 months; (3) inferior vena caval filter placement; (4) acute right ventricular dysfunction/dilation detected echocardiographically after thrombolysis; (5) Doppler recording of pulmonary artery systolic pressure > 50 mmHg after thrombolysis; and (6) greater than 30% obstruction of pulmonary vasculature identified by pulmonary ventilation/perfusion scintigraphy before hospital discharge. Multivariate analysis identified three independent predictors of poor long-term outcome for patients with acute massive pulmonary embolism after thrombolysis; which were: (1) Doppler recording of pulmonary artery systolic pressure > 50 mmHg, with relative risk of 3.78 and a 95% confidence interval of 2.70 to 4.86; (2) echocardiographic evidence of right ventricular dysfunction/dilatation (relative risk: 2.18; 95% confidence interval: 1.48 to 2.88); and (3) greater than 30% obstruction of pulmonary vasculature documented by lung scan (relative risk: 1.99; 95% confidence interval: 1.25 to 2.70).

Conclusion: The study showed that Doppler echocardiographic assessments after thrombolytic therapy and ventilation/perfusion scintigraphy prior to hospital discharge are valuable to establishment of new baseline characteristics, which is informative for risk stratification and prognostication of the long-term outcome for patients with acute massive pulmonary embolism.