Cardiac device & LVAD infections
Left ventricular assist devices (LVADs) and cardiac implantable electronic devices (pacemakers, ICDs) are life-sustaining, but infection — most often by staphylococci (Staphylococcus aureus and biofilm-forming Staphylococcus epidermidis) at the driveline exit site, pump pocket, leads, or outflow graft — is among the most common and lethal complications, affecting roughly 15-30% of LVAD recipients within two years. These biofilm-entrenched infections resist antibiotics and frequently cannot be cured short of device exchange or heart transplantation, options limited by surgical risk and donor scarcity. Lytic bacteriophages are attractive here because their activity is independent of antibiotic-resistance status, they actively penetrate and disrupt staphylococcal biofilm, they self-amplify at the infection focus, and they can be matched strain-by-strain to the patient's own isolate. This makes phages a rational salvage or adjunctive option for destination-therapy patients who are not transplant candidates.
How phages act here
Mechanism
Therapeutic phages are obligately lytic viruses selected against the patient's specific staphylococcal isolate, so a cocktail or "autophage" is host-range-matched (e.g., phages active against an individual's S. aureus or S. epidermidis driveline clone), which broadens coverage and suppresses resistant escape mutants. Unlike most antibiotics, phages express depolymerases and endolysins that degrade the exopolysaccharide matrix and lyse cells embedded in biofilm on driveline tubing and pump surfaces; ex vivo work on explanted LVAD driveline material shows phages reaching biofilm bacteria that antibiotics poorly penetrate. Phage-antibiotic combinations can be synergistic — the strongest in vitro/ex vivo staphylococcal signal pairs phage with rifampicin, an anti-biofilm agent — though synergy is strain- and sequence-dependent and not universal (one S. aureus study found no added benefit and even antagonism when phage preceded antibiotic). Engineered angles under discussion include CRISPR-Cas removal of integrase genes from otherwise-promising temperate staphylococcal phages to lock them into a purely lytic, lysogeny-free state for safe clinical use.
Where it stands
Current evidence
As of 2026 the evidence is early-stage: single-patient case reports, small retrospective case series, and in vitro/ex vivo proof-of-concept work, with no completed randomized trial for this indication. The landmark case (Aslam et al., J Heart Lung Transplant 2019, UC San Diego/IPATH) reported adjunctive local phage therapy plus antibiotics for an S. aureus LVAD infection, and a companion Microbiome 2021 paper tracked the microbiome through that staphylococcal device treatment. A 2022 case (Rojas et al., Antibiotics) treated an S. aureus LVAD outflow-graft/intrathoracic infection with a local phage cocktail (SniPha 360) delivered in a viscous galenic alongside surgical wound management. The most rigorous staphylococcal device data are ex vivo: Pitton et al. (Open Forum Infect Dis 2025) isolated patient-derived phages from 45 LVAD patients and showed phage vB_SepS_BE22 plus rifampicin gave a ~1.9-log biofilm reduction on explanted driveline material against S. epidermidis. Importantly, Molendijk et al. (J Clin Microbiol 2025) found phages added no benefit over antibiotic monotherapy against an S. aureus driveline isolate and could worsen growth if mistimed — a key cautionary signal. Programs (notably UCSD IPATH and European phage centers) treat these cases under compassionate-use/expanded-access frameworks rather than approved protocols.
Evidence confidence: low
The data
Key studies & trials
- Aslam S, Pretorius V, Lehman SM, Morales S, Schooley RT. Novel bacteriophage therapy for treatment of left ventricular assist device infection. J Heart Lung Transplant. 2019;38(4):475-477. ↗
- Pitton M, Valente LG, Oberhaensli S, Gözel B, Jakob SM, Sendi P, Fürholz M, Cameron DR, Que YA. Targeting Chronic Biofilm Infections With Patient-derived Phages: An In Vitro and Ex Vivo Proof-of-concept Study in Patients With Left Ventricular Assist Devices. Open Forum Infect Dis. 2025;12(4):ofaf158. ↗
- Molendijk MM, Verkaik NJ, de Vogel CP, et al. In vitro activity of antibiotic monotherapy and combination therapy with bacteriophages against Staphylococcus aureus LVAD-driveline infections. J Clin Microbiol. 2025;63(11):e0027225. ↗
- Rojas LJ, et al. Bacteriophage-Enriched Galenic for Intrapericardial Ventricular Assist Device Infection. Antibiotics (Basel). 2022;11(5):602. ↗
Who is working on it
Programs & centers
The possibility
If center-based phage banks and rapid host-matching mature, a surgeon could one day debride an infected driveline, swab the patient's own staphylococcal clone, and within days irrigate the pocket with a custom lytic cocktail in a slow-release gel — turning an inevitable pump exchange into a device-sparing rescue. Pairing such cocktails with rifampicin, and CRISPR-engineering temperate skin phages into clean lytic agents, could give destination-therapy patients who can never receive a transplant a genuine path to cure rather than lifelong suppression. The realistic near-term win is a personalized adjuvant that buys time and biofilm control, not a stand-alone replacement for surgery and antibiotics.