Clinical utility of echocardiography for the diagnosis of native valve infective endocarditis in Staphylococcus aureus bacteremia

Abstract

Background The incidence of Staphylococcus aureus infective endocarditis (IE) is steadily rising due to advances in health care delivery. Routine echocardiography is essential in the management of Staphylococcus aureus bacteremia (SAB). The aim of this retrospective cohort study was to characterize the real‐world use of echocardiography in adult patients with SAB and native valve S aureus IE. Methods Using an academic hospital microbiological database, all cases of SAB in adults between 2010 and 2016 were identified. Demographic, echocardiographic, and clinical features were recorded. Results A total of 738 episodes of SAB were identified, of which 504 (68%) patients underwent transthoracic echocardiography (TTE) within 30 days. Of 73 patients with definite IE, 46 (63%) patients had definite IE diagnosed on the initial TTE. An additional 14 (19%) patients had definite IE diagnosed on repeat TTE, 6 (8%) on transesophageal echocardiography (TEE), and 7 (10%) were diagnosed without fulfilling Duke echocardiographic criteria. The yield of repeat TTE was comparable to that of TEE for identifying new vegetations not identified on the initial TTE (17% vs 21%, P = .78). Conclusions Most cases of IE in SAB were identified using TTE alone, with repeat TTE improving the diagnostic yield in the setting of clinical decompensation.

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.…”

“…A potential restriction when applying these scores is that both their development and validation studies have been performed in cohorts without universal echocardiographic assessment, and only a small proportion of patients have undergone TEE. Several authors have demonstrated that carrying out an echocardiogram in a larger proportion of patients implies a higher rate of IE diagnoses (20,21,31,32). It has even been proposed that performing an echocardiogram in these patients may be associated with lower mortality (33).…”

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

“…A potential restriction when applying these scores is that both their development and validation studies have been performed in cohorts without universal echocardiographic assessment, and only a small proportion of patients have undergone TEE. Several authors have demonstrated that carrying out an echocardiogram in a larger proportion of patients implies a higher rate of IE diagnoses [ 24 , 25 , 26 , 36 , 37 ]. It has even been proposed that performing an echocardiogram in these patients may be associated with lower mortality [ 38 ].…”

“…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.…”