By Jeffrey Zimmet, MD, PhD
Synopsis: In this registry of patients undergoing mechanical aspiration for right-sided infective endocarditis, technical success rates were high, with a modest but significant rate of procedural complications. Further research with randomized trials will be needed to better define proper patient selection.
Source: El Sabbagh A, Hibbert B, Bangalore S, et al. Outcomes of percutaneous mechanical aspiration in right-sided infective endocarditis: A multicenter registry. J Am Coll Cardiol. 2025;86(12):846-856.
Right-sided infective endocarditis (RSIE) has long been a challenging entity to treat, with data suggesting a shift in recent years driven both by younger patients with injection drug use and by older patients with cardiac implantable electronic devices. Although medical management relies on prolonged intravenous antibiotics, a significant subset of patients fails medical management as the result of large vegetations, persistent bacteremia, septic emboli, or heart failure. Many of these patients are ineligible for open surgery. For these high-risk patients, alternative approaches are necessary.
Since the approval of the AngioVac catheter by the U.S. Food and Drug Administration (FDA) in 2014, catheter-based percutaneous mechanical aspiration (PMA) has been used as a minimally invasive option for debulking right-sided vegetations, offering the possibility of infection source control in scenarios where standard therapy fails and surgery is precluded. The recently reported CLEAR-IE registry addresses the safety and outcomes of PMA in RSIE.
The CLEAR-IE registry captured the experience of 256 patients who underwent PMA for RSIE at 19 U.S. centers between 2014 and 2024. The median patient age was 43 years, with 43% women and just more than half reporting injection drug use. Half of the patients had acute pulmonary embolism at presentation, while more than one-quarter were classified as having shock. Tricuspid valve lesions predominated, with a median vegetation size of 2.4 cm, and baseline severe tricuspid regurgitation (TR) was seen in 31% of cases. Staphylococcus aureus was the most common pathogen (74%).
Entry criteria for the registry were broad, encompassing patients with persistent RSIE despite antibiotics, large vegetations, and those experiencing complications, such as embolism or heart failure. Operator experience was not specified, nor was the device employed, although the AngioVac system was used in 85% of cases.
Procedural success in the registry was defined as at least a 70% reduction in vegetation size or a final size of 1 cm or less, assessed by operator-selected echocardiographic modalities. The primary composite endpoint was in-hospital death, new pulmonary embolism (PE), or emergency cardiac surgery. Secondary endpoints tracked the individual components as well as new or worsened tricuspid regurgitation.
Of those treated, PMA was technically successful in 89% of cases, with residual vegetations averaging 0.7 cm, and almost 87% completed the procedure without direct procedural complications. Notably, 94% of patients were bacteremic at baseline and almost all saw clearance of blood cultures soon after PMA.
Despite these positive results, PMA was not without significant risk. The composite safety endpoint occurred in 18% of patients, broken down as 9.8% in-hospital mortality, 8.3% new PE, and 3.1% requiring emergency surgery. Additionally, among patients without severe TR at baseline, nearly 17% developed significant worsening of tricuspid valve function, a complication that did not correlate directly with other adverse outcomes but remains clinically meaningful.
Baseline severity also played a role in outcome prediction. Patients who were hypoxic or in shock at baseline were much more likely to reach the composite endpoint, and hypoxia remained a significant predictor of poorer outcome on multivariate analysis. This suggests that patient acuity — rather than procedural details alone — strongly influences the risk for serious adverse events.
The authors reported that CLEAR-IE shows PMA to be a technically viable and frequently effective way to debulk vegetations and control infection in RSIE. Rapid culture clearance particularly is notable given its association with lower in-hospital mortality. However, the considerable rate of serious adverse events compels restraint and highlights PMA as a tool that should be reserved for those at highest risk when alternatives are exhausted. The authors urge further randomized trials to clarify true clinical effect and proper patient selection.
Commentary
For U.S. cardiologists managing endocarditis, PMA broadens the scope of therapeutic options for refractory RSIE, enabling intervention in patients who previously faced limited alternatives. With acceptable technical success rates and high culture clearance in a sick population, PMA has the potential to shift outcomes in select cases. Although the registry’s results are positive overall, the risks of PMA demand careful consideration. Serious complications — including significant mortality, recurrent embolic events, and surgery — occurred in nearly one-fifth of patients, a figure that cannot be ignored given the underlying frailty in this population. Worsening TR is relevant, since it may portend poorer long-term outcomes. Moreover, the lack of granular exclusion criteria in the registry means that clinicians remain without validated predictors for who is most likely to benefit from PMA.
These findings highlight the tension between technological innovation and patient safety. The registry’s lack of refined inclusion criteria means clinicians must individualize decision-making, weighing procedural risks against the trajectory of complicated RSIE. Those with persistent infection, large vegetations, and ongoing embolic phenomena after exhaustion of standard therapy may warrant consideration, but the majority of RSIE patients should be treated conservatively with antibiotic therapy.
For the field to move forward, more data are needed — not just on procedural outcomes, but also on patient characteristics that best predict benefit and risk. Randomized controlled trials, with validated endpoints and subgroup analyses, will be crucial to defining PMA’s role. Until then, cardiologists should regard PMA as a promising but cautious adjunct, reserved for the highest-risk cases and implemented in collaboration with multidisciplinary teams.
Jeffrey Zimmet, MD, PhD, is Associate Professor of Medicine, University of California, San Francisco; Director, Cardiac Catheterization Laboratory, San Francisco VA Medical Center.
