What question did this study set out to answer?

This trial aims to evaluate the safety and effectiveness of enVast-assisted mechanical thrombectomy in STEMI patients with large thrombus burden undergoing primary PCI.

April 17, 2026Open Access

The use of mechanical thrombectomy in patients with STEMI and large thrombus burden: design and rationale of the NATURE trial.

Key Result

enVast-assisted mechanical thrombectomy will be evaluated in the NATURE trial to assess its safety and efficacy in reducing infarct size among STEMI patients with large thrombus burden.

Key Points

This trial aims to evaluate the safety and effectiveness of enVast-assisted mechanical thrombectomy in STEMI patients with large thrombus burden undergoing primary PCI.
Prospective, multicenter, two-arm randomized clinical trial.
Patients are randomly assigned to experimental arm (enVast-assisted mechanical thrombectomy) or control arm (standard care).
Randomization stratified by site, time from symptom onset, and use of parenteral antiplatelet agents.
Scheduled follow-up occurs at 30, 150, and 365 days post-randomization.
Primary endpoint: infarct size assessed via CK-MB activity.
Expected decrease in AUC for CK-MB activity by 30% with enVast-assisted thrombectomy.
Study will involve 148 STEMI patients with complete primary endpoint assessments.
A central core-lab will analyze ECG, coronary angiography, cardiac MRI, and echocardiography results.

Structured PICO

Does enVast-assisted mechanical thrombectomy reduce infarct size in STEMI patients with large thrombus burden undergoing primary PCI?

Population

148 STEMI patients with large thrombus burden (LTB) undergoing primary percutaneous coronary intervention (PCI)

Intervention

enVast-assisted mechanical thrombectomy followed by conventional PCI

Comparator

Standard of care (conventional PCI)

Outcome

Infarct size assessed by the area under the curve for creatin kinase myocardial band (CK-MB) activitysurrogate

The NATURE trial will determine if enVast-assisted mechanical thrombectomy reduces infarct size compared to standard PCI in STEMI patients with large thrombus burden.

Main Result

Absolute Event Rate: 0% vs 0%

Abstract

The optimal management of patients with ST-segment elevation myocardial infarction (STEMI) with large thrombus burden (LTB) undergoing primary percutaneous coronary intervention (PCI) remains unsettled. The NATURE (clinicaltrials.gov, NCT04969471) study is a prospective, multicenter, two-arm randomized clinical trial designed to assess the safety and effectiveness of the enVast stent retriever as an adjunctive reperfusion strategy in STEMI patients with LTB undergoing primary PCI. Eligible patients consenting for trial participation are randomly allocated (1:1) to enVast-assisted mechanical thrombectomy followed by conventional PCI (experimental arm) versus standard of care (control arm). Randomization is stratified by site, time from symptom onset (≤ 3 versus >3 h) and intended use of parenteral antiplatelet agents (i.e. glycoprotein IIb/IIIa inhibitors or cangrelor). Scheduled follow-up visits take place at 30 (±7) days, 150 (±60) days, and 365 (±30) days post-randomization. The primary endpoint is the infarct size assessed by the area under the curve for creatin kinase myocardial band (CK-MB) activity. Clinical events will be adjudicated by an independent Clinical Events Committee. A central core-lab will analyse 12‑lead ECG, coronary angiography examinations, cardiac magnetic resonance imaging and echocardiography examinations. A sample size of 148 (74 per arm) STEMI patients with complete primary endpoint assessment will provide a 90% power with a two-sided 5% significance level to detect a decrease in the AUC for CK-MB by 30%. The NATURE trial is the first randomized clinical trial aimed at investigating if enVast-assisted mechanical thrombectomy as adjunctive reperfusion strategy is safe and may reduce infarct size in STEMI patients with LTB undergoing primary PCI. TRIAL REGISTRATION: ClinicalTrials.gov number, NCT04969471.