Reducing Mortality in Patients With Right-Sided Infective Endocarditis

Aminoglycosides used in combination with β-lactam or vancomycin could reduce 30-day mortality in patients with right-sided infective endocarditis (RSIE), according to research published in BMC Infectious Disease.

RSIE morbidity and mortality are reportedly less severe than left-sided endocarditis and accounts for 5% to 10% of all endocarditis episodes. Studies on the prognostic factors and outcomes in RSIE are lacking, making it hard to provide optimal management. In this study, researchers explored outcome and associated prognostic factors in patients with RSIE requiring intensive care unit (ICU) admission.

Between 2002 and 2012 in Northern France, critically ill patients with RSIE in 10 ICUs in 8 hospitals were evaluated for prognostic factors and the relevance of therapeutic procedures proposed by international guidelines. Adult patients with right-sided, definitive, active, and severe infective endocarditis (IE) requiring ICU admission were included in the study. Active endocarditis was defined as requiring ICU patient admission before or within 30 days of antimicrobial treatment. Severity was associated with acute respiratory failure requiring mechanical ventilation, shock, Simplified Acute Physiology Score (SAPS II) ≥20, or Sequential Organ Failure Assessment (SOFA) ≥3. Patients with both right- and left-sided IE and patients with implantable cardiac electronic device (ICED) infection without tricuspid or right-sided pulmonary valve vegetation were excluded.

A total of 37 patients (mean age: 47.9±18.4; 54% men) met the inclusion criteria. Reason for ICU admission was: respiratory failure (n=12), cardiac failure (n=11), septic shock (n=9), renal failure (n=4), and other cause (n=1). Endocarditis was classified as community-acquired (n=19), hospital-acquired (n=14), and ICED-associated (n=4). Mean SAPS II, SOFA, and Charlson Comorbidity Index were 32.4±17.4, 6.3±4.4, and 3.1±3.4, respectively.

All patients received at least 1 antimicrobial agent within 48 hours of endocarditis diagnosis. Of the patients, 14 had vegetation sizes >20mm and 11 patients had severe tricuspid regurgitation. In addition, 14 patients underwent surgical procedures and 22 patients were administered aminoglycosides in combination with b-lactam or vancomycin. Main outcome measure was 30-day mortality following ICU admission. Patients were defined as one of two groups at 30 days following ICU admission: survivors or non-survivors.

Overall, the mortality of patients with RSIE needing ICU admission was high and dependent on the origin of the infection and preexisting comorbidities. The overall 30-day mortality rate after ICU admission was 21.6%. Prognosis was more favorable generally in young and otherwise healthy injecting drug users (IDUs) described as having minimal right-sided valve dysfunction, low risk for pulmonary embolism, and a good response to appropriate antibiotic therapy. Prognosis was more severe in non-IDUs, with a mortality rate of 27.6%.

Causative pathogens, size of vegetation, and severity of sepsis were not found to be prognostic factors. Multivariate analysis identified the use of aminoglycosides as the only prognostic factor associated with improved outcome (odds ratio, 0.1; P =.007). Staphylococcus aureus was reported as the main causative pathogen (n=26) and study results suggest that treatment with an initial antimicrobial therapy — aminoglycosides used in combination with b-lactam or vancomycin — reduced 30-day mortality. In addition, the removal of ICED associated with IE was an absolute necessity as patients who did not undergo ICED removal died.

Although data were collected retrospectively, the study investigators concluded that, “mortality of patients with RSIE needing ICU admission is high” and suggested that aminoglycosides could reduce 30-day mortality. 

Reference

Georges H, Leroy O, Airapetian N, et al; Hauts de France endocarditis study group. Outcome and prognostic factors of patients with right-sided infective endocarditis requiring intensive care unit admission. BMC Infect Dis. 2018;18:85.