A Prospective, Randomized Controlled Trial of Intravascular Ultrasound-Guided versus Digital Subtraction Angiography-Guided Mechanical Thrombectomy in Acute Intermediate-Risk and High-Risk Pulmonary Embolism.

PURPOSE: This study aimed to compare the efficacy and safety of intravascular ultrasound (IVUS)-guided mechanical thrombectomy with those of conventional digital subtraction angiography (DSA)-guided mechanical thrombectomy in patients with intermediate- to high-risk acute pulmonary embolism. MATERIALS AND METHODS: This is a prospective, 1:1 block-randomized, controlled, open-label, blinded-endpoint (PROBE design), multi-center, superiority trial (Protocol Version 1.0, dated February 1, 2025). Eligible patients aged 18-75 years, diagnosed with intermediate-high-risk acute pulmonary embolism, with right ventricular/left ventricular diameter ratio (RV/LV) ≥ 0.9 on computed tomography pulmonary angiography (CTPA) will be included. The exclusion criteria included unsuitable vascular anatomy for the thrombectomy device; chronic pulmonary hypertension; left bundle branch block; chronic left heart failure (LVEF ≤ 30%); renal dysfunction (serum creatinine > 1.8 mg/dL or > 159 μmol/L); coagulopathy; contrast media hypersensitivity. The intervention group will undergo IVUS-guided mechanical thrombectomy using the Tendvia System (Shanghai Tendvia Medical Devices Co., Ltd.) under the guidance of a Philips IVUS system. The control group will undergo conventional DSA-guided mechanical thrombectomy using the same Tendvia System. The primary efficacy endpoint is the reduction in the RV/LV ratio from baseline to 48 h post-procedure. The primary safety endpoint is a composite of major adverse events (MAEs) within 48 h, including procedure-related mortality, major bleeding, and clinical deterioration requiring escalation of care.