Prevalence and Mortality of Infective Endocarditis in Community-Acquired and Healthcare-Associated Staphylococcus aureus Bacteremia: A Danish Nationwide Registry-Based Cohort Study

Abstract

Background: Staphylococcus aureus bacteremia (SAB) can be community-acquired or healthcare-associated, and prior small studies have suggested that this mode of acquisition impacts the subsequent prevalence of infective endocarditis (IE) and patient outcomes.

Methods: First-time SAB was identified from 2010 to 2018 using Danish nationwide registries and categorized into community-acquired (no healthcare contact within 30 days) or healthcare-associated (SAB >48 hours of hospital admission, hospitalization within 30 days, or outpatient hemodialysis). Prevalence of IE (defined from hospital codes) was compared between groups using multivariable adjusted logistic regression analysis. One-year mortality of S aureus IE (SAIE) was compared between groups using multivariable adjusted Cox proportional hazard analysis.

Results: We identified 5549 patients with community-acquired SAB and 7491 with healthcare-associated SAB. The prevalence of IE was 12.1% for community-acquired and 6.6% for healthcare-associated SAB. Community-acquired SAB was associated with a higher odds of IE as compared with healthcare-associated SAB (odds ratio, 2.12 [95% confidence interval {CI}, 1.86-2.41]). No difference in mortality was observed with 0-40 days of follow-up for community-acquired SAIE as compared with healthcare-associated SAIE (HR, 1.07 [95% CI, .83-1.37]), while with 41-365 days of follow-up, community-acquired SAIE was associated with a lower mortality (HR, 0.71 [95% CI, .53-.95]).

Conclusions: Community-acquired SAB was associated with twice the odds for IE, as compared with healthcare-associated SAB. We identified no significant difference in short-term mortality between community-acquired and healthcare-associated SAIE. Beyond 40 days of survival, community-acquired SAIE was associated with a lower mortality.

Keywords: Staphylococcus aureus bacteremia; community-acquired; endocarditis; healthcare-associated; infective endocarditis.

Graphical Abstract

Figure 1.

A, Prevalence of infective endocarditis (IE) among patients with community-acquired and healthcare-associated Staphylococcus aureus bacteremia (SAB). B, Prevalence of IE stratified by sex.

Figure 2.

Prevalence of infective endocarditis (IE) among patients with community-acquired and healthcare-associated Staphylococcus aureus bacteremia (SAB), stratified by age group. Box-whiskers show 95% confidence intervals.

Figure 3.

Ninety-day (A) and 1-year (B) mortality for patients with Staphylococcus aureus infective endocarditis, stratified by mode of acquisition. Abbreviations: CA, community acquired; HA, healthcare associated; SAIE, Staphylococcus aureus infective endocarditis.