Validation of VIRSTA and Predicting Risk of Endocarditis Using a Clinical Tool (PREDICT) Scores to Determine the Priority of Echocardiography in Patients With Staphylococcus aureus Bacteremia

Abstract

Introduction Infective endocarditis (IE) secondary to Staphylococcus aureus bacteremia (SAB) has high morbidity and mortality. The systematic use of echocardiography in SAB is controversial. We aimed to validate VIRSTA and PREDICT scores for predicting the risk of IE in Colombian patients with SAB and, consequently, to determine the need for echocardiography. Methodology Cohort of patients hospitalized with SAB in two high complexity institutions in Medellin, Colombia, between 2012-2018. The diagnosis of IE was established based on the modified Duke criteria. The VIRSTA and PREDICT scores were calculated from the clinical records, and their operational performance was calculated. Results The final analysis included 922 patients, 62 (6.7%) of whom were diagnosed with IE. The frequency of IE in patients with a negative VIRSTA scale was 0.44% (2/454). The frequency of IE in patients with a negative PREDICT scale on day 5 was 4.8% (30/622). The sensitivity and negative predictive value (NPV) of the VIRSTA scale was 96.7% and 99.5%, respectively. For the PREDICT scale on day 5, the sensitivity and NPV were 51.6% and 95.1%, respectively. The discrimination, given by the area under the ROC curve (AUC), was 0.86 for VIRSTA and 0.64 for PREDICT. Conclusions In patients with negative VIRSTA, screening echocardiography may be unnecessary due to the low frequency of IE. In PREDICT-negative patients, despite the low frequency of IE, it is not safe to omit echocardiography.

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

“…Its high negative predictive value was ratified in a validation study performed by the same group [ 33 ]. However, other authors have found that this score does not identify low-risk patients with sufficient accuracy [ 20 , 22 , 23 ]. These results are in line with ours.…”

“…The VIRSTA score [ 19 ] incorporates the largest number of variables as compared to the previous score. Consequently, some studies have shown a higher sensitivity [ 22 , 23 ]. Hence, a recent survey showed that 15–20% of experts would recommend not performing TTE, nor TEE, evaluation in patients identified as low-risk with this score.…”

“…It should be noted that most of the patients eventually diagnosed with IE that had been identified as low-risk by the VIRSTA score did not have any identifiable risk factors that would have raised IE suspicion. Ruling out IE in patients with negative VIRSTA and a negative TTE would allow to avoid TEE in approximately half of patients with SAB [ 19 , 22 , 23 ]. However, well-designed studies are needed to confirm the usefulness of this approach.…”

“…These scores can identify patients at low risk of IE in which TEE could be deferred. To date, the scarce validation studies available have yielded controversial results regarding their usefulness to exclude IE without TEE performance [ 21 , 22 , 23 ]. Moreover, all these studies have an important limitation: the low rate of echocardiography assessment, especially TEE, in groups classified as low-risk.…”

Update on Staphylococcus aureus bacteraemia

“…SAB is complex and there are many important aspects that we were not able to explore further at this time including a study with eosinophilia with daptomycin [40], use of oral stepdown therapy with clindamycin [41], improvement of diagnosis using fluorodeoxyglucose positron emission tomography/ computed tomography (FDG-PET/CT) [42,43], source control such as with removal of cardiac implantable electronic devices associated with decreased mortality [44], the importance of serial negative blood cultures [45 & ], and the significance of Staphylococcus aureus bacteriuria in patients with SAB [46 & ]. In addition, optimized use of clinical scoring systems to stratify patients for therapy or best utilize echocardiography resources is a major area of investigation that could merit its own review [47][48][49][50][51][52][53][54].…”