Enterococci as Emerging Pathogens in Infective Endocarditis and Cardiac Device Infections: Future Implications

Enterococci are emerging as important pathogens in an era of an aging population with high healthcare and antibiotic exposure, along with an increasing utilization of prosthetic valves, transcatheter aortic valve replacement (TAVR), and cardiac implantable electronic devices (CIEDs). Contemporary cohorts place enterococci among the three leading causes of infective endocarditis, with highest risk after TAVR, where enterococci account for 15% to 30% of cases in several registries. Enterococci cause a smaller proportion of CIED infections, but present late with lead or valve involvement. Enterococcus faecalis currently causes majority of enterococcal endocarditis. Its endovascular tropism, adhesion to damaged tissue and prosthetic surfaces, biofilm tolerance, and association with occult infective endocarditis during bacteremia make it the principal cardiac species of concern. Enterococcus faecium represents a distinct future threat. Hospital-adapted lineages combine prolonged intestinal colonization, environmental persistence, mobile resistance elements, ampicillin resistance, frequent vancomycin resistance, and biofilm capacity. Absolute burden may rise because the population-at risk-living with cardiac foreign devices is expanding. Future monitoring therefore requires linked, species-level surveillance that connects bacteremia, imaging, recurrence, resistance, and genomic data.