Management of Infective Endocarditis Among Injection Drug Users: A Statement From the AHA

The American Heart Association published a scientific statement in Circulation about the management of infective endocarditis (IE) among individuals who inject drugs.

Injection drug use is an established risk factor for IE. Despite the fact that IE is a life-threatening condition that affects an otherwise young and healthy population, there has been limited research focusing on its prevention and management among people who inject drugs. Current IE management guidelines do not address patients with underlying substance use disorders and no clinical trial data on antimicrobial therapy and surgical interventions among this patient population has been published.

In the United States (US), addiction treatment has long been detached from mainstream medical care. The statement authors stated that treating IE without addressing addiction and substance use disorders fails to consider the underlying cause of the illness. Clinicians should make every effort to address injection drug use by employing a nonjudgmental approach such that harm, complications, and poor outcomes may be avoided.

For people who inject drugs, hospitalization for medical or surgical complications can be a reachable moment. Validated screening tools should be integrated into admission protocols to help identify injection drug users. Clinicians should obtain a history of drug use and withdrawal as well as previous experience with addiction treatment.

The authors advocated for educating people who inject drugs on safer injection drug use to reduce risk for future infection. Safer use includes not licking needles or the injection site, using sterile water for drug preparation, only using sterile needles, cleaning skin with alcohol prior to injection, using lower-risk injection sites (hands, arms, feet, legs), to avoid using alone, and carrying naloxone.

For antimicrobial IE interventions, the statement concentrated on invasive staphylococcal infections, as 1 in 10 of staphylococcal IE infections in the US is attributed to injection drug use. The standard management approach for S. aureus-associated IE is 6 weeks of intravenous antibiotics. Although the authors recommend this therapeutic regimen for people who inject drugs, the authors recognized that this regimen is often not feasible for that patient population. In situations where a 6-week intravenous regimen is not reasonable, growing evidence suggests partial intravenous therapy followed by oral antibiotics may be an effective alternative strategy.

Potential treatment options include dicloxacillin plus rifampin or ciprofloxacin plus rifampin in the case of methicillin susceptibility; linezolid plus rifampin, trimethoprim-sulfamethoxazole, or doxycycline for methicillin resistance or penicillin allergy; and dalbavancin or oritavancin for patients with other contraindications.

Recurrent IE is common among people who inject drugs, such that 41.1% of people who inject drugs with IE receive a valve procedure. The indications for receiving a procedure in people who inject drugs are the same as patients with non-drug-related IE. However, the authors noted that the proportion of patients with right-sided IE is higher among people who inject drugs.

The statement authors wrote, “It is clear that more needs to be done to curb the ongoing epidemic of injection drug use and its infectious complications, including IE…Going forward, the writing group hopes that this scientific statement serves as a valuable tool for the frontline clinician to help close the gaps in the disparity of care for [people who inject drugs] with IE.”

Reference

Baddour LM, Weimer MB, Wurcel AG, et al. Management of infective endocarditis in people who inject drugs: a scientific statement from the American Heart Association. Circulation. Published online August 31, 2022. doi:10.1161/CIR.0000000000001090