Prospective Validation of PREDICT and Its Impact on the Transesophageal Echocardiography Use in Management of Staphylococcus aureus Bacteremia

Abstract

Background Infective endocarditis (IE) is the most feared complication of Staphylococcus aureus bacteremia (SAB). Transesophageal echocardiogram (TEE) is generally recommended for all patients with SAB, however, supporting data for this are limited. We previously developed a scoring system, “PREDICT”, that quantifies the risk of IE and identifies patients who would benefit the most from undergoing TEE. The current prospective investigation aims to validate this score. Methods We prospectively screened all consecutive adults (≥18 years) hospitalized with SAB at three Mayo Clinic sites between January 2015 and March 2017. Results Of 220 patients screened, 199 with SAB met study criteria and were included in the investigation. Of them, 23 (11.6%) patients were diagnosed with definite IE within 12 weeks of initial presentation based on modified Duke’s criteria. Using the previously derived PREDICT model, the day 1 score of ≥4 had a sensitivity of 30.4% and a specificity of 93.8%, whereas day 5 score of ≤2 had a sensitivity and negative predictive value of 100%. Additional factors including surgery or invasive procedure in the past 30 days, prosthetic heart valve, and higher number of positive blood culture bottles in the first set of cultures were associated with increased risk of IE independent of the day 5 risk score. Conclusion We validated the previously developed PREDICT scoring tools for stratifying risk of IE, and the need for undergoing a TEE, among cases of SAB. We also identified other factors with predictive potential, although larger prospective studies are needed to further evaluate possible enhancements to the current scoring system.

Re: ‘Time to blood culture positivity in Staphylococcus aureus bacteraemia to determine risk of infective endocarditis’ by Kahn et al

“…In our PREDICT validation cohort, we also found that patients with SAB and IE had a significantly shorter TTP than did those with SAB and no evidence of IE with a median time of 11 hr (range 8e14 hr) compared with 15 hr (11.5e18 hr) in those without IE [13]. Sensitivity of TTP at 11, 12 and 13 hr for a diagnosis of IE was 65%, 65% and 74%, respectively, whereas specificity was 75.7%, 74% and 70%, respectively, with a negative predictive value of 94%, 94% and 95%, respectively.…”

Blood culture time to positivity in non-β-hemolytic streptococcal bacteremia as a predictor of infective endocarditis—a retrospective cohort study

“…3 Including osteomyelitis, spondylodiscitis, gastroinstestinal infection, urogenital infection, airway infection, and soft tissue infection. 4 From the time positive blood culture was drawn…”

“…3 Univariate statistical analyses were performed using the Mann-WhitneyU test or the Kruskal-Wallis test. 4 Statistical analysis performed via multivariate regression analysis. 5 S. mitis indicated as baseline NBHS group in statistical analysis…”

Short time to blood culture positivity in Enterococcus faecalis infective endocarditis

“…A short TTP has been associated with poor outcome in bacteremia with Staphylococcus aureus [4][5][6], Streptococcus pneumoniae [7], Pseudomonas aeruginosa [8], and nontyphoid Salmonella [9]. Moreover, a short TTP is associated with an endovascular source of infection, including infective endocarditis (IE), in bacteremia with S. aureus [5,10,11]. Recently, we suggested that TTP is useful to determine the need for echocardiography in S. aureus bacteremia [12].…”