Researchers say a host of new risk factors are driving more hospital-acquired heart valve infections and that should compel healthcare providers to re-evaluate their strategies for reducing the threat to patients.
A recent analysis of more than 21,000 records of hospitalized patients in New Jersey from 1994 to 2015 found that beginning in 2004, there was a sharp rise in patients developing heart valve infections while being treated for other health conditions.
The results were published Monday in the American Journal of Cardiology. The study showed hospital-acquired heart valve infections have increased as the number of community-acquired heart valve infections have declined.
The study's lead author Dr. Abel Moreyra, professor of medicine at Rutgers University Robert Wood Johnson Medical School, said the increase in hospital-acquired heart valve infections seems to have begun around the same time as when the American Heart Association in 2007 changed its guidelines for preventing such infections. Previously, the AHA recommended all people at risk for heart valve infections take antibiotics for prevention. But 12 years ago, the organization called for limiting the use of antibiotics to only patients at high risk for infection.
But Moreyra said the AHA's current preventative guidelines don't reflect the shift in the risk factors for heart valve infections.
Over the past 20 years a combination of factors, including a rise in intravenous drug abuse, immuno-compromised patients, and people receiving medical device implants have all contributed to a significant proportion of infective endocarditis cases being acquired in healthcare settings and caused by staphylococcus microorganisms, which are harder and more expensive to treat.
Heart valve infection, also known as infective endocarditis, is caused by bacteria entering the bloodstream and moving into the heart lining, a heart valve or a blood vessel.
The AHA's guidelines were originally designed to help prevent heart valve infections caused by streptococcus bacteria in the mouth and called for taking penicillin. The AJC study along with other evidence has found most hospital-acquired heart valve infections are being caused by staphylococcus bacteria—which is very common in hospitals and can lead to heart failure or stroke in endocarditis patients.
Staphylococcus is harder to treat than streptococcal infections and requires more powerful antibiotics.
Dr. Ann Bolger, professor emeritus at the University of California-San Francisco School of Medicine, speaking on behalf of the AHA, said using preventative antibiotics for staphylococcal endocarditis could do patients harm and increase the risk of the bacteria becoming resistant, which would then put patients' at even greater risk.
"There's no way that you're going to be exposing patients to prophylactic doses of anti-staphylococcal meds before every single potential exposure in a hospital environment," Bolger said.
Efforts to prevent and control the spread of infective carditis have been complicated by the opioid epidemic, which experts say has been arguably the single greatest contributor to the increase in heart valve infections in recent years. A recent study published Sept. 18 in the Journal of the American Heart Association found the prevalence of drug abuse related to heart infections went from 8% in 2002 to 16% by 2016.
According to a 2017 study in the Journal of the American College of Cardiology, roughly 40,000 to 50,000 cases of infective endocarditis occur in the U.S. each year, costing hospitals on average $120,000 per patient to treat.
Bolger said current best practices for infection control and prevention were enough to prevent the spread of staphylococcus-related endocarditis in hospitals.
"The best practices in terms of avoidance and control is absolutely where our attentions need to be focused, Bolger said.
