Opioid drop drives decline in drug-related heart infection hospitalizations

A new national study found that hospitalizations for serious heart infections associated with drug use are declining after years of increases, driven largely by a decrease in opioid-associated cases.

Published today in Clinical Infectious Diseases, the study analyzed national hospitalization data from 2016 through 2022 to identify trends in drug use-associated infective endocarditis. Researchers identified more than 118,000 hospitalizations nationwide during the seven-year period. Hospitalizations peaked at approximately 18,700 in 2020, during the COVID-19 pandemic, before declining by 18% to about 15,300 in 2022.

Infective endocarditis is a potentially life-threatening infection that occurs when bacteria or other germs enter the bloodstream and infect the inner lining or valves of the heart. The infection, which can occur when people inject drugs, can cause permanent heart damage, require lengthy hospital stays or lead to death.

Our goal was to provide an updated national picture of these serious infections, which often affect younger adults in their 30s. With opioid injection historically accounting for a large share of these infections, we wanted to understand whether greater availability to addiction treatments and harm reduction services, along with changes in how people use drugs, may have influenced hospitalization trends nationwide."

Paul Christine, MD, PhD, paper's first author, assistant professor of medicine, University of Colorado Anschutz

Potential reasons behind the decline

The researchers hypothesized several possible factors contributing to the decline. One possible explanation is expanded access to addiction treatment and harm reduction services for opioid use, such as access to sterile syringes and education about safer drug use practices, as well as greater efforts to connect people with opioid use disorder to medications that can help them enter recovery.

Another possible explanation is a shift from injecting drugs to smoking them. Because injecting drugs can introduce bacteria into the bloodstream, fewer people injecting may be helping reduce the risk of developing these serious infections.

Stimulants outnumbered opioid cases in parts of the country

The researchers also pointed out another key finding: while opioid-associated hospitalizations are declining, stimulants such as methamphetamine and cocaine are accounting for a growing share of these serious infections, particularly in the Western part of the United States.

• The researchers estimated a 59% probability of stimulant-involved infective endocarditis in the Pacific region, compared to 34% in New England.
• Nationwide, in 2016, approximately 37% of drug use associated endocarditis hospitalizations involved stimulants, either alone or in combination with opioids. By 2022, that proportion had increased to nearly 47%.

"I believe the problem isn't simply that stimulants are becoming more prominent. It's that the healthcare system currently has fewer effective tools to treat stimulant use disorder than opioid use disorder," said Christine.

He explained that while significant attention and resources have been rightly devoted to treating opioid use disorder, comparatively fewer efforts have focused on engaging and treating people who use stimulants. Additionally, unlike opioid use disorder, which has several effective medication options, there are currently no FDA-approved medications specifically for stimulant use disorder.

Christine and his colleagues want to next explore more effective hospital-based interventions for patients who use stimulants, with a focus on helping them access addiction treatment and connect with ongoing care after discharge.

They also want to investigate next whether similar declines are occurring in other serious infections associated with drug use, including skin, soft tissue and bone infections.