CHICAGO — The incidence of infective endocarditis has increased and prescriptions of antibiotic prophylaxis have declined in England since the introduction of the 2008 National Institute for Health and Care Excellence guidelines, according to data presented at the American Heart Association Scientific Sessions.
Before 2007, most guideline committees around the world recommended antibiotic prophylaxis for patients at moderate and high risk for infective endocarditis, Martin Thornhill, MBBS, BDS, PhD, MSc, from the University of Sheffield, U.K., said during a press conference.
“In 2007, the American Heart Association guidelines committee decided that antibiotic prophylaxis was only needed in patients at high risk, and most other countries followed in the lead given by the AHA,” Thornhill said. “However, in the United Kingdom, because of the lack of any evidence to support the efficacy of antibiotic prophylaxis, the National Institute for Health and Care Excellence [NICE] … which produces guidelines in the United Kingdom, recommended antibiotic prophylaxis should stop completely for all patients in March 2008.”
This provided the impetus for Thornhill and colleagues to test the impact of the antibiotic prophylaxis cessation on infective endocarditis, which has been associated with a mortality rate of 10% to 20%.
From March 2008 to March 2013, Thornhill reported that prescriptions per month of amoxicillin or clindamycin decreased from 10,900 to 1,307, a reduction of almost 90% (P<.001). During that period, the number of infective endocarditis cases increased above the projected historical trend by 0.11 cases per 10 million people per month (95% CI, 0.05-0.16; P<.0001), leading to an incidence higher than anticipated by approximately 35 cases per month (175 vs. 140), a 25% increase. Furthermore, there was also a significant rise in the number of cases of endocarditis in both the highest-risk and lower-risk groups.
“Despite the association that is clear between these events, however, we cannot draw the conclusion that there is a cause-and-effect relationship between the fall in antibiotic prophylaxis prescribing and the rise in infective endocarditis,” Thornhill said.
He added that NICE has issued a press release stating that the institute will immediately review its guidelines. – by Brian Ellis
For more information:
Thornhill M. LBCT.03: Treatment of Structural Heart Disease. Presented at: American Heart Association Scientific Sessions; Nov. 15-19, 2014; Chicago.
Dayer MJ. Lancet. 2014;doi:10.1016/s0140-6736(14)62007-9.
Disclosure: Thornhill reports no relevant financial disclosures.