Morphologic characteristics of central pulmonary thromboemboli predict thrombolytic efficacy in massive pulmonary embolism

Objective

On hospital admission, the morphology of the central pulmonary artery thromboemboli is an independent predictor of 30-day mortality in patients with massive pulmonary embolism (MPE). This may be due to different susceptibility of thromboemboli to thrombolysis. The aim of this study was to assess the efficancy of thrombolysis in patients with MPE and morphologically different thromboemboli.

Design

A prospective observational study.

Setting

An 11-bed closed medical ICU at a 860-bed community general hospital.

Patients

Twelve consecutive patients with shock or hypotension due to MPE and central pulmonary thromboemboli detected by transesophageal echocardiography who were treated with thrombolysis between January 2000 and April 2002.

Procedures

Patients were divided into two groups according to the characteristics of detected central pulmonary thromboemboli: Group 1, thrombi with one or more long, mobile parts; and Group 2, immobile thrombi. Urokinase infusion was terminated when mixed venous oxygen saturation was stabilized above 60% for 15 min.

Results

At 2 hours the total pulmonary vascular resistance index was reduced more in Group 1 compared with Group 2 (27 ± 12 to 14 ± 6 mmHg/[l/min/m²] [-52%] vs 27 ± 8 to 23 ± 10 mmHg/[l/min/m²] [-15%], respectively; P = 0.04). In Group 1 thrombolysis was terminated earlier compared with Group 2 (89 ± 40 min vs 210 ± 62 min, respectively; P = 0.0024). The cumulative dose of urokinase used in Group 1 was lower compared with Group 2 (1.7 ± 0.3 MIU vs 2.7 ± 0.5 MIU, respectively; P = 0.023).

Conclusion

Thrombolysis is more efficient in patients with mobile central thromboemboli detected by transesophageal echocardiography during MPE.