Endocarditis Increases in Covid Times Among People with Substance Use Disorders

The incidence rate of endocarditis—a rare but often fatal inflammation of the heart valves—among patients with cocaine use disorder or opioid use disorder increased from 2011 to 2022, with the steepest increase occurring from 2021 to 2022, a new study reports. 

Study findings, published in Molecular Psychiatry, contribute to expanding evidence of endocarditis as a significant and growing health concern for people who inject drugs, a risk exacerbated during the Covid-19 pandemic. The study, led by NIDA, was funded by multiple NIH institutes and centers.

Among patients with either substance use disorder, those who were clinically diagnosed with Covid-19 faced a higher risk of a new endocarditis diagnosis as well as hospitalization following this diagnosis than those who did not have Covid-19. Over the full 12-year period, the rate of endocarditis was three to eight times greater in patients with opioid and cocaine use disorder.

The findings also showed that Black and Hispanic people faced a lower risk of Covid-19-associated endocarditis than non-Hispanic white people. The authors noted this is consistent with higher prevalence of injection drug use in non-Hispanic white populations. 

One in 10 hospitalizations for endocarditis is associated with injection drug use, and these numbers continue to rise. Use of unsterile injection equipment dramatically increases risk of infection in people who use drugs. 

NIDA Director Dr. Nora Volkow and a team of scientists at Case Western Reserve University analyzed electronic health record data of more than 109 million unique patients collected from January 2011 through August 2022. Patient data were derived from 77 hospitals nationwide, covering diverse geographic locations, age groups, racial and ethnic groups, income levels and insurance types. 

A clinical diagnosis of Covid-19 more than doubled the risk for new diagnosis of endocarditis in patients with either cocaine or opioid use disorder. Among these patients, the risk of hospitalization within 180 days following diagnosis of endocarditis was about 68% in patients with Covid-19, compared to 59% in those without. 

“As the scientific understanding of long Covid develops, we can now include endocarditis as one long-term effect on key organ systems for people who inject drugs,” said Dr. Rong Xu of Case Western University and co-corresponding author of this study. “It’s critical that we continue to monitor long-term, broad impacts of Covid-19 on people who use drugs.”