Scan to Thrombectomy: Hub-and-Spoke Network for Interventional Pulmonary Embolism Care

Document Type

Conference Proceeding

Publication Date

10-2024

Publication Title

Chest

Abstract

PURPOSE: Percutaneous mechanical thrombectomy (PMT) is a potential treatment option for pulmonary embolism (PE); the efficacy, safety, and treatment algorithms for this procedure are in the early stages of being explored in the literature. During PMT, a vascular proceduralist aspirates clot burden from the pulmonary arteries, with the goal of reducing strain on the RV (right ventricle), which the FLARE study (Tu, 2019) showed in a single-arm, prospective fashion as measured by RV to left ventricle (LV) ratio at 48 hours. PMT is not currently reflected in guidelines as first-line treatment for most patients and is not available at many smaller/ community hospitals. In these hospitals, if PE with RV strain is diagnosed, then via hub-and-spoke model, transfer to a tertiary center may be arranged to consider PMT. The alternative would be a silo model, where community hospitals develop PMT programs, avoiding inter-hospital transfer time lag, but incurring costs of equipment, training, and maintaining call schedule. "Door-to-balloon" times for myocardial infarction are well established, but there is relatively little written about whether an analogous performance metric timeline ought to exist with the interventional treatment of PE. One pilot study (Kendall, 2018) utilized a STEMI-team for PE patients achieving scan-to-treatment of 7.8 hours. The aim of our study is to provide real-world retrospective data about "scan-tothrombectomy" time comparing hub-originated cases to spoke-originated within a regional hub-and-spoke network. METHODS: We queried the electronic medical record during a two-year period starting October 2020, obtaining data for patients who underwent PMT. We identified 229 encounters, sub-divided into two cohorts: 144 cases hub-originated, 85 cases spoke-originated. We recorded when the CT scan was obtained and when PMT began, calculating the time elapsed. We obtained demographic and clinical data about these patients, and performed statistical comparisons between cohorts based on their location of origin and their sPESI (simplified pulmonary embolism severity index) score. Future analysis with same data set will also seek to adjust for RV:LV ratio. RESULTS: The cohorts were well balanced with respect to age, gender, BMI, and sPESI, the typical patient overall was age 62 with BMI 33 and sPESI of 2 with most having positive troponins. Overall median scan-to-thrombectomy time was 4.4 hours, with hub cases significantly shorter at 3.5 hours, spoke cases 7.0 hours; with difference of 3.5 hours remaining significant adjusting for sPESI (95% CI 2.1-4.6). Independent of location, cases with sPESI score of 4 or greater were initiated the fastest with a median of 3.2 hours. 16 total patients died within 30 days (9 out of 144 at hub, and 7 out of 85 from spoke), 10 within 48 hours. 16 cases met criteria for high risk, with 11 surviving. CONCLUSIONS: Outside hospital (spoke) originated cases had double the scan-to-thrombectomy time compared to tertiary center (hub) originated cases (7.0 hours compared to 3.5 hours). CLINICAL IMPLICATIONS: Design of care networks and future PE guidelines may need to account for the availability and proximity of PMT-capable facilities. Both the choice of reperfusion and the timeliness of the intervention should be evaluated based on patient-centered clinical outcomes.

Volume

166

Issue

4 Suppl

First Page

A5730

Comments

Chest 2024 Annual Meeting, October 6-9, 2024, Boston, MA

DOI

10.1016/j.chest.2024.06.3405

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