Indigo Aspiration Thrombectomy Improves Right Heart Failure Caused by Acute Massive or High-Risk Submassive Pulmonary Embolism

Background: Acute pulmonary embolism (PE), particularly massive and high-risk submassive PE, carries mortality rates exceeding 50% and 15%, respectively. Anticoagulation alone does not effectively reduce mortality. Thrombolytic therapy improves outcomes but poses a substantial bleeding risk. Indigo aspiration thrombectomy alleviates right ventricular pressure overload in acute massive or high-risk submassive PE; however, its effect on PE-related mortality is unknown. This study aimed to determine whether Indigo aspiration thrombectomy improved right heart function and reduced PE-related mortality. Methods: This retrospective cohort study included 46 patients diagnosed with acute massive or high-risk submassive PE who underwent Indigo aspiration thrombectomy between January 2020 and August 2025. The study was conducted in the intensive care unit at China Medical University Hospital, Taichung, Taiwan. Efficacy endpoints were right heart parameters; safety endpoints included major bleeding events and 90-day mortality. Kaplan–Meier survival curve analysis was also performed. Results: Indigo aspiration thrombectomy significantly improved right heart parameters. Pulmonary artery (PA) systolic and mean pressures decreased by 23% (from 57.2 to 44.3 mmHg, p = 0.001; from 35.0 to 26.8 mmHg, p < 0.001). PA pulsatility index increased by 50%, and the right ventricular to left ventricular diameter ratio decreased by 30%. For acute massive PE, the major bleeding rate was 31.3% and PE-related mortality was 25.0%. For acute high-risk submassive PE, the major bleeding and PE-related mortality rates were both 3.3%. Conclusions: Indigo aspiration thrombectomy considerably improves right heart failure and may reduce PE-related mortality in patients with acute massive or high-risk submassive PE.