Drug-Associated Infective Endocarditis On The Rise

— But opioid epidemic role uncertain from death certificate data studied

MedicalToday

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Drug abuse accounts for a growing proportion of infective endocarditis deaths, CDC death certificate data showed.

The number of infective endocarditis deaths among people who inject heroin or other drugs increased threefold from 1999 to 2016 -- double the 1.5-fold absolute increase in endocarditis deaths in the general population, according to Guilherme Oliveira, MD, of University Hospitals Cleveland Medical Center, and colleagues.

Injection drug users comprised 18.9% of infective endocarditis deaths in 2016, up from 9.4% in 1999 (P<0.001), Oliveira's group reported in a research letter published online in .

Among people who injected drugs and died from infective endocarditis, the demographics also shifted younger (from 12.4% to 37.4% under 35, P<0.001) and whiter (60.2% to 88.9%, P<0.001).

The study was based on death certificates from 1999-2016 included in the U.S. Centers for Disease Control and Prevention Multiple Cause-of-Death database. The researchers' search of ICD codes for intravenous drug abuse, psychoactive substance abuse, or acute hepatitis C yielded 55,212 infective endocarditis deaths in people ages 15 to 64 years.

"Taken together, our findings should prompt clinicians to be vigilant when treating people who inject drugs with fevers and to use a low threshold to initiate antibiotic therapy to mitigate further infective endocarditis fatalities," according to the investigators.

Yet the latter recommendation was questioned by Nabin Shrestha, MD, MPH, of Cleveland Clinic, who argued for blood cultures to be obtained before initiating antibiotics in people who inject drugs with fever.

"Doing so will increase the likelihood of making a correct diagnosis of infective endocarditis in such patients," he commented in an interview with . "Antibiotic therapy without a proper diagnosis may actually delay making a diagnosis of endocarditis."

This study contributes to the overall evidence that more and more people are dying of infectious endocarditis, commented Alysse Wurcel, MD, MS, of Tufts Medical Center in Boston, who noted similar trends in her own research. She was not involved in Oliveira's study.

She said that in her personal experience, she saw just one case of drug-associated infective endocarditis in 2008; whereas at her institution now, "any given day we're taking care of five."

Several policy issues are implicated in the growing problem, Wurcel told .

"Unlike some other complications of needle use, like HIV and [hepatitis] C, infective endocarditis is not tracked by any epidemiological surveillance system. There was no way to know this was going to happen until people experienced this and started coming in more and more," she said.

Furthermore, this infection requires 6 weeks of intravenous antibiotics, she added. "We can stabilize them in a week, maybe give them heart surgery. But where do they go after that?" Stigmatization of drug users means that rehabilitation centers and other facilities often won't take them, she said.

"I think the most important thing clinicians need to understand is that infective endocarditis is part of a much bigger problem. The bigger problem is drug addiction. For people who inject drugs with infective endocarditis, clinicians should consider addiction treatment to be as much part of the treatment as antibiotic therapy," according to Shrestha.

That said, Oliveira and collaborators cautioned that their retrospective study isn't enough to attribute the rise of infectious endocarditis deaths among drug users to the opioid crisis per se, suggesting that more virulent and resistant microorganisms may also have a role.

Other limitations to the study were that death certificates are not always accurate in describing cause of death, and that their dataset couldn't distinguish between true infective endocarditis deaths and those where the patient had the infection treated but subsequently died from overdose.

  • author['full_name']

    Nicole Lou is a reporter for , where she covers cardiology news and other developments in medicine.

Disclosures

Oliveira, Shrestha, and Wurcel disclosed no relevant conflicts of interest.

Primary Source

JAMA Cardiology

Njoroge LW, et al "Changes in the association of rising infective endocarditis with mortality in people who inject drugs" JAMA Cardiol 2018; DOI: 10.1001/jamacardio.2018.1602.