ABSTRACT
Background:
The optimal management strategy for intermediate-high risk pulmonary embolism (PE) remains uncertain, particularly regarding the use of catheter-based interventions versus conservative anticoagulation. This prospective study investigates whether hemostatic profiles can predict therapy success and support personalized treatment approaches.
Methods:
This ongoing study includes 100 patients with intermediate-high risk PE, treated with either ultrasound-assisted catheter-directed thrombolysis (USAT, n=25), large bore mechanical thrombectomy (LBMT, n=25), or anticoagulation alone with heparin (n=50). Hemostatic profiles are assessed using TEG6s and standard coagulation parameters. Primary outcome is RV/LV ratio change, secondary outcomes include bleeding events and mortality. Assessments occur at baseline, 24 hours after therapy initiation, and after 6 months.
Results:
As of November 2025, 90 patients have been enrolled (median age 68; 53.3% male). Using unsupervised cluster analysis of baseline TEG parameters two distinct phenotypes could be identified: one hypercoagulable and one hypocoagulable cluster. Hypercoagulabilty was characterized by shorter R-time (10.40 [8.40–17.10] vs 34.70 [15.70–58.00]; p<0.001), steeper alpha angle, (65.70 [54.00–72.40] vs 43.80 [38.00–57.80]; p<0.001) and Maximal Amplitude (60.30 [55.92–64.68] vs 44.80 [32.70–49.30]; p>0.001).
RV/LV ratio reduction at 24–72 hours was significantly greater in the USAT (n=21) and LBMT (n=28) groups compared to heparin (n= 40), (p = 0.006 and p = 0.001, respectively), with median changes of 0.42 (USAT), 0.34 (LBMT), and 0.14 (heparin). Overall, the hypercoagulable cluster tend to benefit more with greater RV/LV ratio reduction, without reaching statistical significance. Only in patients treated with Heparin, RV/LV ratio reduction was significantly greater in Cluster A (0.17 vs 0.06, p=0.012).
Bleeding events included one major (2.5%) in the heparin group, one minor (4.8%) in the USAT group, and five in the LBMT group (three minor [10.7%], two major [7.1%]). In-hospital mortality occurred in one patient in the USAT (4.8%) group, and in three patients (7.5%) in the heparin group. Overall mortality was 4.8% (USAT), 3.6% (LBMT), and 20% (heparin). Bailout therapy with USAT was used in one heparin and one LBMT patient.
Conclusion:
Preliminary data suggest that catheter-based therapies provide more rapid RV unloading than anticoagulation alone in intermediate-high risk PE. Two TEG-defined hemostatic phenotypes were identified, which may relate to treatment response. In the anticoagulation-only group, hypercoagulable patients showed a significantly greater reduction in RV/LV ratio than hypocoagulable patients. A nonsignificant trend toward greater benefit with catheter-based therapies was also observed in the hypercoagulable cluster. These findings are exploratory and require further exploration.
