A commercially available multiplex real-time PCR for detection of pathogens in cardiac valves from patients with infective endocarditis.

Infective endocarditis (IE) is a life-threatening condition, burdened by high mortality. Current guidelines recommend that, in case of negative culture result, tissues from excised heart valves or vegetations from patients with suspected IE should be referred for broad-range bacterial PCR and sequencing. In this proof-of-concept study, the diagnostic utility of the commercially available multiplex real-time PCR system SeptiFast (SF), performed on cardiac valves, was evaluated in a selected population of 20 patients with definite IE of known origin, in comparison with culture. A significant difference was found between SF and culture in the rate of pathogen detection (19 versus 3 respectively; chi-square 14.06; P=0.0002). SF sensitivity was 95%; specificity, 100%; positive predictive value (PPV), 100%; and negative predictive value (NPV), 83.3%. Culture sensitivity was 15%; specificity, 100%; PPV, 100%; and NPV, 22.7%. SF assay, performed on culture-negative excised heart valves, can be useful for the etiological diagnosis of IE.