A Scenario-Based Survey of Expert Echocardiography Recommendations for Patients With Staphylococcus aureus Bacteremia at Varying Risk for Endocarditis

Abstract

IMPORTANCE Echocardiography to detect infective endocarditis is regarded as a key quality indicator in the care of patients with Staphylococcus aureus bacteremia, but its application varies markedly between reported series. Understanding the reasons for this variation in practice is important to improve the use of this investigation.OBJECTIVE To identify expert clinicians' preferred echocardiography strategy for a variety of S aureus bacteremia scenarios in a hypothetical setting free from extrinsic constraints. DESIGN, SETTING, AND PARTICIPANTSAnonymous web-based survey study comprising 50 textbased scenarios describing patients with S aureus bacteremia and various combinations of risk factors for endocarditis. Other variables included patient age and the presence of an extracardiac focus of infection warranting prolonged treatment. The survey was emailed to participants between September 2018 and March 2019. Each respondent was asked to recommend 1 of 6 echocardiography strategies for up to 8 randomly selected scenarios. Respondents were primarily infectious diseases physicians, and more than half reported an annual caseload of more than 20 cases of S aureus bacteremia. MAIN OUTCOMES AND MEASURESThe proportion of respondents selecting each of the 6 echocardiography strategies was calculated alongside Wilson score confidence intervals. Modified Fleiss κ statistics were used to described interrespondent variability. Generalized estimating equations were used to assess the associations between respondent-and scenario-level variables and the recommendation of an echocardiography strategy with a low negative likelihood ratio for infective endocarditis (ie, a highly exclusionary strategy). RESULTSA total of 656 respondents from 24 countries provided 4837 echocardiography recommendations across the 50 scenarios. Echocardiography recommendations were associated with scenarios' burden of endocarditis risk (multivariate odds ratio per point of the VIRSTA score, 1.4; 95% CI, 1.4-1.5; P < .001). Poor interrespondent agreement was seen across all scenarios (modified Fleiss κ, 0.06; 95% CI, 0.05-0.07) but was most notable for scenarios with a lower risk of endocarditis (modified Fleiss κ, 0.04; 95% CI, 0.03-0.05). The presence of an extracardiac focus of infection was also associated with the choice of echocardiography strategy (odds ratio for highly exclusionary strategy, 0.51; 95% CI, 0.45-0.58). Respondent location in continental Europe was associated with recommendations in favor of a highly exclusionary strategy (odds ratio, 1.8; 95% CI, 1.3-2.5) compared with location in Australia or New Zealand. CONCLUSIONS AND RELEVANCEIn this study, expert clinicians demonstrated active stratification by risk of endocarditis when making echocardiography recommendations for hypothetical patients with S aureus bacteremia. Substantial disagreement existed as to whether patients at lower risk of (continued) Key Points Question Which echocardiography strategies do expert clinicians recommend for patients with Staphylococcus aureus bacter...

The Use of Clinical Prediction Rules without Echocardiographic Evaluation in Staphylococcus aureus bacteraemia may not be Enough to Exclude Infective Endocarditis and be Associated with Increased Mortality

“…Secondly, our predefined cut-off points are not prospectively validated. Nevertheless, both the IE risk percentages selected and the use of NLR have previously been proposed and accepted by several authors (8,24,26,27,32). Thirdly, we cannot exclude that the higher 30-day mortality found in patients with no echocardiogram is caused to uncontrolled confounding variables.…”

“…Despite this controversial results and limitations, some authors recommend forgoing echocardiographic evaluation (even TTE) in patients with no identifiable risk factor (22,23). Furthermore, a recent scenario-based survey showed that approximately 15-20% of experts would recommend not performing TTE in patients with negative VIRSTA score (24).…”

Unreliability of Clinical Prediction Rules to Exclude without Echocardiography Infective Endocarditis in Staphylococcus aureus Bacteremia

“…Second, our predefined cutoff points are not prospectively validated and are based on scarce evidence. Nevertheless, both the IE risk percentages selected and the use of NLR have previously been proposed and accepted by several authors [ 12 , 17 , 21 , 29 , 32 , 37 ]. Third, we cannot exclude that the higher 30-day mortality found in patients with no echocardiogram is caused to uncontrolled confounding variables.…”

“…Despite these controversial results and limitations, some authors recommend forgoing echocardiographic evaluation (even TTE) in patients with no identifiable risk factor [ 27 , 28 ]. Furthermore, a recent scenario-based survey showed that approximately 15–20% of experts would recommend not performing TTE in patients with negative VIRSTA score [ 29 ].…”

Redefining Staphylococcus aureus bacteremia: A structured approach guiding diagnostic and therapeutic management

“…Recent reports suggest that certain clinical factors are already used in this manner to justify ordering echocardiography 22 or other imaging 23 in patients with SAB. This use of risk stratification is not an absolute classification in SAB, but rather should be considered as supplemental data with which to assess the individual risk of a particular patient with SAB.…”