Safety and efficacy of Computer Assisted Vacuum Thrombectomy

Clinical, Functional, and Quality of Life Outcomes after Computer Assisted Vacuum Thrombectomy for Pulmonary Embolism Interim Analysis of the STRIKE-PE Study

Clinical question

How safe and effective is Computer Assisted Vacuum Thrombectomy for treating Pulmonary Embolism?

Take away point

There is a significant reduction in pulmonary artery pressure and right ventricle to left ventricle ratios as well as improvement in 90-day functional and quality of life outcomes associated with the use of Computer Assisted Vacuum Thrombectomy.

Reference

Moriarty JM, Dohad SY, Schiro BJ, et al. Clinical, Functional, and Quality of Life Outcomes after Computer Assisted Vacuum Thrombectomy for Pulmonary Embolism: Interim Analysis of the STRIKE-PE Study. Journal of vascular and interventional radiology. Published online May 1, 2024. doi: https://doi.org/10.1016/j.jvir.2024.04.028

‌Study design

Prospective observational cohort study.

Funding Source

Industry sponsored; Penumbra.

Setting

International multi-institutional study across the USA and Europe.

Figure

Summary

The annual incidence of pulmonary embolism (PE) is increasing and there is significant associated morbidity for surviving patients in terms of decreased overall quality of life. Endovascular treatment strategies have promising clinical outcomes. But longer-term patient-reported outcomes and PE associated morbidity are lacking. The STRIKE-PE study is a muti-institutional prospective study evaluating the long-term safety and treatment outcomes after computer aided vacuum thrombectomy of PE. This article is the first interim analysis of the STRIKE-PE study and evaluates the safety and effectiveness of computer assisted vacuum thrombectomy (CAVT) for the first 150 patients through 90-day follow-up.

All 150 patients were treated with the Indigo Aspiration Mechanical thrombectomy system in combination with the automated computer assisted algorithm. The right ventricle to left ventricle (RV to LV) ratio and incidence of major adverse events within 48 hours were the primary endpoints of the study.
· The RV to LV ratio was assessed on computed tomography pulmonary angiograms.
· Major adverse events included device-related death, major bleeding, device associated pulmonary vascular or cardiac injury and clinical deterioration including prolonged end-organ hypoperfusion or cardiopulmonary resuscitation.

Quality of life and functional improvements were utilized as secondary endpoints.
· Functional outcomes were assessed using the Borg scale of dyspnea at rest and the New York Heart Association classification of heart failure.
· Quality of Life was assessed using the EQ-5D-5L questionnaire, the EQ visual analog scale and the Pulmonary Embolism Quality of Life questionnaire.

Overall, the authors found that the use of computer assisted vacuum thrombectomy was associated with a 16.3% reduction in pulmonary artery pressures, a 25.7% reduction in the RV to LV ratio. Four (2.7%) of the patients experienced major adverse events within 48 hours. Patients exhibited statistically significant improvements in their quality of life at 90 days after the procedure.

The authors discussed that their observed 25.7% reduction in RV to LV ratio was similar to other prospective single-arm clinical studies assessing endovascular approaches for the treatment of PE. The total device time in this study, 33.5 minutes, was lower, although the total procedure time was comparable to other aspiration thrombectomy studies. The reported major adverse events seen during the current study included major bleeding and device related clinical deterioration, which were similar to prior studies. Due to a relative paucity of data in literature, the authors were unable to compare the observed functional and quality of life improvements. However, the authors did emphasize that the FDA and the European Agency for the Evaluation of Medicinal Products both recommend monitoring patient-reported outcomes as effective endpoints in similar clinical trials. The limitations of the study included a lack of comparison with other procedural interventions and medical management with anticoagulation. In addition, as the functional and quality of life questionnaires are not specific to pulmonary embolism, concurrent treatment of other comorbid conditions may have confounded the data. Finally, there was potential bias as the RV to LV ratio was reported by the treating physicians and not through standardized core laboratory examination.

In conclusion, the authors reported that treating PE with computer assisted vacuum thrombectomy resulted in improved RV to LV ratios and pulmonary arterial pressures with an acceptable safety profile as well as improved functional and quality of life outcomes at 90-day follow-up.

Commentary

The authors reported the interim results from ongoing STRIKE-PE trial. The study was tailored to prospectively evaluate the safety and long-term outcomes of computer assisted vacuum thrombectomy with a large patient population from multiple institutions. The reported initial results demonstrated decreased right heart strain and improved 90-day functional and quality of life outcomes. There remained a paucity of data in literature examining the long-term patient outcomes after treatment of PE, which is of paramount importance for informing morbidity of surviving patients after PE treatment. The recognition of this importance by the FDA, and the inclusion of functional outcome assessment in this and other similar clinical trials represented progress in the field where long-term morbidity is regarded as important as the immediate clinical success. A potential area of improvement involves the development of PE-focused functional and quality of life measures, which can allow PE-specific assessment rather than a generalized morbidity questionnaire.

Approximately 3% of patients in this study experienced major adverse events associated with computer assisted vacuum thrombectomy, suggesting a strong safety profile. Also, the mitigation of blood loss can decrease the need for blood transfusion. Furthermore, the median ICU stay was 1 day and 38% of the patients did not require postprocedural ICU level of care. Finally, the total device time associated with computer assisted vacuum thrombectomy was less than similar mechanical thrombectomy devices though the total procedure time was comparable. This data can be leveraged by Interventional Radiology departments to acquire the necessary PE treatment equipment.

The STRIKE-PE trial is still ongoing, and it will be interesting to see the safety and immediate clinical outcomes of the entire patient population of 600 patients, as well as longer-term morbidity and functional outcomes. Future trials can also focus on comparing the efficacy of computer assisted vacuum thrombectomy with other methods of treatment. Overall, the initial interim results from the STRIKE-PE trial bolsters the use of computer assisted vacuum thrombectomy for PE with promising safety and effectiveness profile.

Post Author
Aniket Pandya, MD
ESIR Resident, PGY-4
University of Massachusetts Chan Medical School