Prospective registry of PTE patients who underwent FlowTriever, with 6 months of follow-up.
The clinical relevance of interventional treatment in pulmonary thromboembolism (PTE) is often discussed, and no clinical studies have demonstrated a decrease in “hard” outcomes such as mortality.
However, in recent years the use of catheter-directed therapies has increased, either through its main indication, which is for patients with absolute or relative contraindications for thrombolytics, or in patients who, despite anticoagulant therapy, do not show improvement.
Toma et al. conducted the FLASH registry (FlowTriever All-Comer Registry for Patient Safety and Hemodynamics) to evaluate the safety and efficacy of the FlowTriever system in real-life patients. It is a prospective, multicenter registry that included patients older than 18 years with intermediate-risk or high-risk PTE who underwent thrombectomy. Patients who were not candidates for anticoagulant therapy or with a life expectancy of less than 30 days were excluded.
The primary endpoint (PEP) was a composite of major adverse events (MACE) within 48 hours, procedure-related death, major bleeding, and procedural complications. Secondary endpoints were individual analysis of each element in the primary endpoint, access-related complications, or serious device-related adverse events. Secondary effectiveness endpoints were changes in post-procedure hemodynamic parameters.
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The study included 799 patients. Their mean age was 61.2 years and 54% of subjects were male; 7.9% were at high risk and 92.1% at intermediate risk (83.2% were at intermediate-high risk). About 65% had concomitant deep vein thrombosis (DVT) and 32.1% had an absolute contraindication to receive thrombolytics.
The average thrombectomy time was 43 minutes. Some other type of post-FlowTriever therapy (mostly catheter-based thrombolytics) was needed by 2.4% of subjects, with a postintervention ECMO requirement in 0.4% of cases.
No deaths occurred during the procedure for the studied cohort. The rate for all-cause mortality (not attributed to the procedure) was 0.3% at the 48-hour follow-up and 0.8% at 30 days. The MACE rate was 1.4%, mostly bleeding-related.
There was a decrease in mean pulmonary artery pressure (mPAP) from 32.6 ± 9.0 to 24.6 ± 8.9 mmHg (-7.6 mmHg on average, [-23.0%], p < 0. 0001), a significant increase in the proportion of patients with normal mPAP after thrombectomy (p < 0.0001), and an increase in the cardiac index from 1.64 ± 0.26 to 1.93 ± 0.58 L/min/m2 (0.29 L/min/m2 mean change [18.9%]; p < 0.0001). In turn, pulmonary vascular resistance decreased from 6.65 ± 3.21 to 4.99 ± 2.76 mmHg-min/L (-1.67 mmHg-min/L, mean change [-20.1%]; p < 0.0001).
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When analyzing the severe pulmonary hypertension subgroup (PAPs ≥70), which accounted for 12.7% of the included cohort, there was a decrease of 18.1 mmHg on average (-22.4%; p < 0.0001). Clinically, dyspnea improved (-1.7 points in mMRC score on average [-61.2%]; p < 0.0001) and the proportion of patients without oxygen requirement increased from 10.5% to 71.2% at 48 h (p < 0.0001).
When regression was performed, the variables associated with a greater reduction in PAPm were DVT and the presence of bilateral or saddle PTE (p = 0.027 and p = 0.010).
Conclusions
This is the largest prospective registry on interventional treatment with thrombectomy in PTE, with almost 800 patients enrolled. It showed a favorable safety profile (major adverse effects in 1.8% of cases), an effect that was also evident in patients with severe PHT (greater benefit).
Dr. Omar Tupayachi.
Member of the editorial board of SOLACI.org.
Original Title: Acute outcomes for the full US cohort of the FLASH mechanical thrombectomy registry in pulmonary embolism.
Reference: Toma C, Jaber WA, Weinberg MD, et al. Acute outcomes for the full US cohort of the FLASH mechanical thrombectomy registry in pulmonary embolism [published online ahead of print, 2022 Sep 18]. EuroIntervention. 2022;18(14):1201-1212. doi:10.4244/EIJ-D-22-00732.
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