TOPLINE: 

Culture-negative infective endocarditis (IE) accounted for about 1 in 13 cases of IE. Patients with this condition presented less often with fever or sepsis and more often with embolic complications, underwent extensive diagnostic imaging, and had similar survival outcomes compared to patients with culture‑positive IE.

METHODOLOGY:

• Researchers analyzed data from a Danish retrospective registry to compare culture‑negative and culture‑positive IE and describe contemporary patterns of diagnosis and treatment.
• They included 2875 adults hospitalized with first-time left-sided IE between January 2016 and December 2021.
• IE was defined as culture‑negative when no bacterial pathogen was identified from blood cultures, valve tissue culture, or polymerase chain reaction. A multidisciplinary team validated the diagnoses, and PET‑CT was used when indicated.
• Researchers evaluated medical history, IE-specific features, diagnostic and treatment practices, and outcomes such as in‑hospital mortality; 1-year all‑cause mortality; and a composite of new or recurrent IE, embolic events, and unplanned valve surgery.

TAKEAWAY:

• Overall, 7.4% of patients had culture‑negative IE; their median age was 72 years, and 38.7% were women.
• At hospital admission, patients with culture-negative IE vs culture-positive IE less often had fever (44.3% vs 61.7%) and sepsis (7.1% vs 24.6%) but more often had embolic events (25.9% vs 10.8%) and valvular insufficiency (11.3% vs 7.4%; P < .05 for all).
• Patients with culture-negative IE had a smaller median size of vegetation (8 mm vs 10 mm; P = .04). Rates of infection of the prosthetic valve and valve surgery were similar between groups.
• PET-CT was performed in about two thirds of patients in both groups. Rates of in-hospital mortality and 1-year mortality after discharge did not differ between groups.

IN PRACTICE:

“At presentation, patients with CNIE [culture-negative IE] were less likely to have fever or sepsis but more likely to exhibit advanced disease manifestations, including heart failure and valvular dysfunction. The former presentation likely reflects, at least in part, the administration of empirical antibiotic therapy before establishment of the IE diagnosis, whereas the latter presentation may indicate a diagnostic delay in CNIE, with cardiac symptoms ultimately prompting recognition of the disease,” the researchers of the study wrote.

SOURCE:

The study was led by Jeppe K. Petersen, MD, of University Hospital Copenhagen in Copenhagen, Denmark. It was published online on April 1 in JACC.

LIMITATIONS:

The study was observational; thus, selection bias and unmeasured confounding may have affected the results. The registry did not record data on prehospital antibiotics or whether serologic tests were conducted. Detailed data on surgery and pathology were missing.

DISCLOSURES:

The authors did not list a specific funding source for this study. Three authors reported receiving independent research grants from the Novo Nordisk Foundation. Two authors reported receiving speaker fees from multiple multinational pharmaceutical companies, and one of them also reported receiving speaker fees from a medical technology firm. 

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.