New Study Questions How Long Heart Infection Patients Need Antibiotics

Patients being treated for infective endocarditis (a bacterial infection of the inner lining of the heart, usually affecting the valves) have long been advised to complete up to six weeks of intravenous antibiotics. According to the New England Journal of Medicine, that recommendation is largely based on expert consensus rather than firm trial evidence.

The POET II trial has now examined what researchers call a response-tailored strategy — adjusting the length of antibiotic treatment based on how individual patients are responding, rather than applying a fixed duration to everyone. The journal published its findings alongside a short explanatory video summarising the results.

The research focuses specifically on left-sided endocarditis, which affects the mitral or aortic valves and carries a higher risk of serious complications than infection on the right side of the heart. It’s a condition that typically requires hospital admission and close monitoring throughout treatment.

The trial’s name carries significance: POET II follows an earlier Danish study — POET I — which found that switching stable patients from intravenous to oral antibiotics partway through treatment produced comparable outcomes. That earlier work shifted clinical thinking considerably. This second trial appears to take that question a step further, asking not just how antibiotics are delivered, but for how long.

No changes to NHS treatment guidelines have been announced. Patients currently receiving treatment for endocarditis should continue to follow the advice of their clinical team and not adjust their medication based on early research findings.

Anyone with concerns about heart symptoms or ongoing treatment should contact their GP or call NHS 111. In a medical emergency, call 999.