Introduction

Patients with acute pulmonary embolism (PE) are at risk for development of persistent right heart dysfunction or even chronic thromboembolic pulmonary hypertension (CETPH). Thrombus resolution is necessary to avoid these severe outcomes
There are numerous strategies to provide thrombus resolution including ultrasound-assisted catheter-directed thrombolysis (UACDT), which is a therapeutic option by the ESC 2019 guidelines. Regardless of the acute therapy regime, anticoagulation for at least 3 to 6 months is suggested as standard therapy for all patients with PE. 

Methods

Between October 2017 and August 2022, we analyzed all patients after UACDT due to intermediate-high or high-risk PE in an all-comers registry.
We implanted the UACDT-catheter within 24 h after admission. Over 15 hours, 11.5 mg alteplase were administered per catheter. Patients received unfractionated heparin for at least 48 hours periinterventional and were treated with other anticoagulants afterwards.
They were followed up at the earliest three months after discharge of the target hospitalization with UACDT. 

Results

We performed UACDT in 84 patients (52 % female, mean age 66 ± 17 years, BMI 30.7 ± 6.7 kg/m²).
Within 24 hours, sPAP decreased from 46 ± 15 mmHg pre-UACDT to 31 ± 8 mmHg post-UACDT, RV/LV ratio from 1.1 ± 0.1 initially to 0.9 ± 0.2 (both p < 0.05). Four patients died in hospital.
At discharge, 46 patients (58 %) still showed signs of right ventricular stress determined by transthoracic echocardiography.

Follow-up was available from 33 of these patients (72%). 49 % were females, mean age was 64 ± 16 years, BMI 29.3 ± 5,8 kg/m². Mean follow-up time was 180 ± 132 days. 15 patients had initially received apixaban, 11 edoxaban, 6 rivaroxaban and one received a vitamin k antagonist.
Mean RV/LV ratio decreased from 1.1 ± 0.2 to 0.8 ± 0.2 in comparison to pre-UACDT, sPAP from 42 ± 5 to 32 ± 10 mmHg (p < 0.05, both) mmHg, BNP and nt-proBNP also sank significantly. Mean walking distance was 419 ± 151 m. Blood gas analysis was normal in 97 %. One patient showed a mild hypoxemia not requiring continuous long-term oxygen therapy.

Of the initial 84 patients, 13 patients (16 %) still showed signs of right ventricular dysfunction at follow up.
sPAP was 40 ± 10 mmHg, RV/LV ratio 1.0 ± 0.3. Mean walking distance was 373 ± 104 m. Blood gas analysis was normal in all patients except one with afore mentioned mild hypoxemia not requiring continuous long-term oxygen therapy.

Of those patients with right ventricular stress at discharge, 28% still showed signs of right ventricular dysfunction at follow up. Six patients developed a CTEPH and were treated with riociguat.
Age, BMI, sPESI initial BNP, nt-proBNP or invasive PAP did not differ significantly between patients with or without persistent right heart dysfunction. Only initial troponin was significantly higher in patients who did not recover until the follow-up date (263 ± 240 vs. 184 ± 96 g/ml, p < 0.05)

Conclusion

The risk for development of persisting right heart dysfunction after intermediate-high or high-risk PE treated by UACDT in our collective was 16 %. 28 % of the patients who were discharged with signs of right heart stress did not recover until follow-up. High initial troponin may be used to detect patients at risk for development of persisting right heart dysfunction.