Percutaneous Mechanical Aspiration Shows Promise for Right-Sided Infective Endocarditis: Insights from the CLEAR-IE Registry

Percutaneous Mechanical Aspiration (PMA) shows promise for patients with right-sided infective endocarditis (RSIE) who do not respond to medical treatment. Data from the CLEAR-IE study indicate PMA's potential to clear infections and reduce mortality.

The increase in RSIE cases is attributed to rising numbers of people using injectable drugs and those with implantable cardiovascular devices or indwelling catheters. Current treatments have limitations—antimicrobials are often ineffective, and surgery carries high morbidity and mortality risks.

Devices originally designed for pulmonary embolism are now being used to aspirate vegetation, reducing infection sources similarly to draining pus or abscesses. The goal in RSIE is to debulk vegetation and improve microbial efficacy.

The CLEAR-IE registry provided real-world data on PMA's safety and efficacy, laying groundwork for a possible randomized controlled trial. PMA has shown unique benefits for patients, especially those with a history of IV drug use who may struggle with follow-up care.

The treatment strategy includes aspirating infection sources, rehabilitating the underlying addiction, and postponing surgery until the risk of reinfection is reduced. This multistep approach aims to improve long-term outcomes.

For the CLEAR-IE analysis, researchers evaluated 256 patients who underwent right-sided PMA at 19 U.S. centers. Most infections were bacterial, commonly Staphylococcus aureus, and the median vegetation size was 24 mm.

Procedural success was high, with 89.4% achieving a significant reduction in vegetation size. The primary efficacy outcome of culture clearance was reached in 92.4% of cases, while the primary safety outcome occurred in 18% of patients.

Among predictors for culture clearance were bacterial infections, absence of residual vegetation, and an immunocompetent state. Importantly, culture clearance was tied to a lower in-hospital mortality risk.

Safety predictors included baseline hypoxia, shock, and shorter durations on effective antibiotics. Hypoxia emerged as the strongest predictor of worse safety outcomes.

By six weeks post-treatment, some patients had left against medical advice or were lost to follow-up, with 7.6% experiencing recurrence, 8% hospitalized for heart failure, and 2.7% with a new pulmonary embolus.

The registry suggests that PMA provides high rates of procedural success and clinical efficacy for select RSIE patients who are refractory to medical therapy. Adverse events remained a consideration, largely driven by the severity of underlying endocarditis.

Guidelines currently differ, with European guidelines giving PMA a class IIb recommendation. Although further studies are needed, the CLEAR-IE registry offers foundational data, potentially paving the way for a randomized trial.