Infective endocarditis increases tenfold in North Carolina

Endocarditis is an infection of one or more heart valves. Usually, this condition is seen in older patients as these valves age and become weaker. Yet, bacteria introduced into the body through injection drug use can also cause endocarditis, a phenomenon doctors around the state are seeing in startling rates.

"Drug-associated infective endocarditis is markedly increasing across North Carolina," said Asher Schranz, M.D., the study's author and a fellow in the UNC Division of Infectious Diseases. "It causes severe illness, and treatment is expensive. This condition has been somewhat overlooked, but it is a huge problem that needs appropriate attention."

Schranz presented the study's findings at IDWeek in San Francisco in October.

In collaboration with colleagues at Duke University and the N.C. Division of Public Health, Schranz studied state data on endocarditis hospitalizations from 2007 to 2017. They found a tenfold increase in the number of hospitalizations due to drug-associated infective endocarditis, with the most significant spike in the past four years. As recently as five years ago, less than 10 heart valve replacement surgeries were done to treat drug-associated endocarditis. Now, 109 surgeries are done annually in North Carolina to treat drug-associated endocarditis, and overwhelmingly occur in young persons. The median age of persons undergoing surgery for this condition is 33.

And these surgeries come with an expensive price tag. The median hospital charge for the entire hospitalization with valve replacement surgery $251,000. More than 280 drug-associated endocarditis valve replacement surgeries were performed in North Carolina over the past 10 years, totaling about $78 million.

"We found that 73 percent of patients with drug-associated infective endocarditis were uninsured or on Medicaid," Schranz said. "This means the cost of the surgery and hospitalization are absorbed by patients, individual hospitals, and government budgets, which finance Medicaid."

The increase in the number of hospitalizations and surgeries for drug-associated infective endocarditis as well as the burden the high cost of treatment has on hospitals and Medicaid are the key takeaways from Schranz and his colleagues' research. They would like future studies to focus on the long-term outcomes of valve replacement surgery, including reinfection, repeat surgeries and drug overdose. The team would also like to explore ways to enhance delivery of addiction care services to patients while they are in the hospital and after discharge.