Prevalence of infective endocarditis in patients with Staphylococcus aureus bacteraemia: the value of screening with echocardiography.

AIMS: Staphylococcus aureus infective endocarditis (IE) is a critical medical condition associated with a high morbidity and mortality. In the present study, we prospectively evaluated the importance of screening with echocardiography in an unselected S. aureus bacteraemia (SAB) population. METHODS AND RESULTS: From 1 January 2009 to 31 August 2010, a total of 244 patients with SAB at six Danish hospitals underwent screening echocardiography. The inclusion rate was 73% of all eligible patients (n= 336), and 53 of the 244 included patients (22%; 95% CI: 17-27%) were diagnosed with definite IE. In patients with native heart valves the prevalence was 19% (95% CI: 14-25%) compared with 38% (95% CI: 20-55%) in patients with prosthetic heart valves and/or cardiac rhythm management devices (P= 0.02). No difference was found between Main Regional Hospitals and Tertiary Cardiac Hospitals, 20 vs. 23%, respectively (NS). The prevalence of IE in high-risk patients with one or more predisposing condition or clinical evidence of IE were significantly higher compared with low-risk patients with no additional risk factors (38 vs. 5%; P < 0.001). IE was associated with a higher 6 months mortality, 14(26%) vs. 28(15%) in SAB patients without IE, respectively (P < 0.05). CONCLUSION: SAB patients carry a high risk for development of IE, which is associated with a worse prognosis compared with uncomplicated SAB. The presenting symptoms and clinical findings associated with IE are often non-specific and echocardiography should always be considered as part of the initial evaluation of SAB patients.

Infective endocarditis: long-term reversibility of kidney function impairment. A 1-y post-discharge follow-up study.

The aim of this study was to quantify the long-term reversibility of kidney function decrease occurring during hospitalization and treatment for infective endocarditis (IE). A prospective observational cohort study was performed at a tertiary university hospital in Copenhagen from October 2002 through May 2008; 223 consecutive IE patients were included. Forty patients died in hospital and 38 within 1 y of discharge. Of the 145 patients called in for the 1-y follow-up, 111 accepted. Kidney function was assessed by estimated endogenous creatinine clearance (EECC). Statistical correlation between EECC at admission, discharge and follow-up, as well as correlations between gentamicin and EECC changes, were analyzed. In the 111 follow-up patients, the bacteriological aetiologies were: Streptococcus species (47.7%), Enterococcus (16.2%) and Staphylococcus aureus (11.7%). The mean EECC decrease from admission to discharge was 8.4% (95% confidence interval 1.6-15.2; p < 0.001). However this kidney function impairment was reversed at the 1-y follow-up. When divided into subgroups, a full kidney function restitution was seen in only 35.1% of patients with an EECC decrease of >22%. In conclusion, kidney function impairment occurring during hospitalization for IE is potentially reversible within the first y post-discharge.

Severity of gentamicin's nephrotoxic effect on patients with infective endocarditis: a prospective observational cohort study of 373 patients.

BACKGROUND: Gentamicin is often used to treat infective endocarditis (IE). Gentamicin is highly effective, but its applicability is reduced by its nephrotoxic effect. The aim of this study was to quantify the nephrotoxic effect of gentamicin and the association between the nephrotoxic effect and mortality in patients with IE. METHODS: A prospective observational cohort study was performed at 2 tertiary university hospitals in Copenhagen from October 2002 through October 2007; 373 consecutive patients with IE were included. A total of 287 (77%) of the patients received gentamicin treatment (median duration, 14 days); dosage was adjusted according to daily serum creatinine and trough serum gentamicin levels. Kidney function was determined by estimated endogenous creatinine clearance (EECC). Statistical correlation between gentamicin and EECC change was analyzed, and the association between mortality and nephrotoxicity was investigated. RESULTS: The primary bacteriological etiologies were as follows: Streptococcus species (37.1%), Staphylococcus aureus (18.2%), and Enterococcus species (16.1%). In the gentamicin group, the mean EECC change was an 8.6% decrease, but in the no-gentamicin group, the mean change was an increase of 2.3% (P = .05). The decrease in EECC was significantly correlated with the duration of gentamicin treatment: a 0.5% EECC decrease per day of gentamicin treatment (P = .002). The decrease in EECC during hospitalization was not related to postdischarge mortality. The mean duration of follow-up was 562 days. CONCLUSIONS: The nephrotoxic effect of gentamicin is directly related to treatment duration, with a decrease in EECC of 0.5% per day of gentamicin treatment. In patients treated with gentamicin, the in-hospital decrease in EECC was not related to postdischarge mortality. Consequently, this study does not support abolishment of gentamicin in treatment of IE.

Major cerebral events in Staphylococcus aureus infective endocarditis: is anticoagulant therapy safe?

OBJECTIVES: To study the impact of anticoagulation on major cerebral events in patients with left-sided Staphylococcus aureus infective endocarditis (IE). METHODS: A prospective cohort study; the use of anticoagulation and the relation to major cerebral events was evaluated separately at onset of admission and during hospitalization. RESULTS: Overall, 70 out of 175 patients (40%; 95% CI: 33-47%) experienced major cerebral events during the course of the disease, cerebral ischaemic stroke occured in 59 patients (34%; 95% CI: 27-41%), cerebral infection in 23 patients (14%; 95% CI: 9-19%), and cerebral haemorrhage in 5 patients (3%; 95% CI: 0.5-6%). Patients receiving anticoagulation were less likely to have experienced a major cerebral event at the time of admission (15%) compared with those without anticoagulation (37%, p = 0.009; adjusted OR: 0.27; 95% CI: 0.075-0.96; p = 0.04). In-hospital mortality was 23% (95% CI: 17-29%), and there was no significant difference between those with or without anticoagulation. CONCLUSIONS: We found no increased risk of cerebral haemorrhage in S. aureus IE patients receiving anticoagulation. Anticoagulation was associated with a reduced risk of cerebral events before initiation of antibiotics. Data support the continuance of anticoagulation in S. aureus IE patients when indicated.

One-year mortality in coagulase-negative Staphylococcus and Staphylococcus aureus infective endocarditis.

The aim of this study was to investigate in-hospital mortality and 12-month mortality in patients with coagulase-negative Staphylococcus (CoNS) compared to Staphylococcus aureus (S. aureus) infective endocarditis (IE). We used a prospective cohort study of 66 consecutive CoNS and 170 S. aureus IE patients, collected at 2 tertiary university hospitals in Copenhagen (Denmark) and at 1 tertiary university hospital in Gothenburg (Sweden). Median (range) C-reactive protein at admission was higher in patients with S. aureus IE (150 mg/l (1-521) vs 94 mg/l (6-303); p<0.001), which may suggest a more serous infection. CoNS was associated with prosthetic valve IE (49% vs 24%; p<0.001) and median diagnostic delay was longer in CoNS IE patients (20 d (0-232) vs 9 d (0-132); p<0.001). In-hospital mortality was equally high in both groups but 25% of the CoNS IE patients had died after 1 y compared to 39% of patients with S. aureus IE (p =0.05). In conclusion, CoNS IE was associated with a long diagnostic delay and high in-hospital mortality, whereas post-discharge prognosis was better in this group of patients compared to patients with IE due to S. aureus.

The impact of cardiac surgery in native valve infective endocarditis: can euroSCORE guide patient selection?

BACKGROUND: Decision making regarding surgical intervention in native valve endocarditis (NVE) is often complex and surgery is withheld in a number of patients either because medical treatment is considered the best treatment or because the risk of operation is considered too high. The objective of this study was to investigate the outcome of surgical treatment and to validate the ability of euroSCORE to predict operative mortality in NVE patients. METHODS: Prospective cohort study including 323 consecutive NVE patients. Patients were divided into 3 groups based on treatment strategy and indication/contraindication for surgery. The additive and logistic euroSCORE was calculated and the observed and predicted mortality was compared. RESULTS: Cardiac surgery was associated with a good prognosis, in-hospital and after 12months, compared to conservative treatment. After adjustment for confounders surgery was associated with a survival benefit (hazard ratio (HR) 0.45, 95% CI: 0.27-0.76%; p=0.003). When propensity score was used in regression adjustment, cardiac surgery was still associated with a better outcome after 12months (HR 0.41, 95% CI: 0.25-0.68; p<0.001). Observed mortality for patients receiving surgical treatment was 11% compared to a mean logistic euroSCORE mortality of 16% (NS). The discriminating ability of euroSCORE was good, area under the ROC curve 0.74 (95% CI: 0.64-0.84; p<0.001) logistic model and 0.75 (95% CI: 0.65-0.86; p<0.001) additive model. CONCLUSIONS: Cardiac surgery was associated with a good prognosis when indicated regardless of euroSCORE, and surgery should only be withheld after thorough consideration. EuroSCORE remains a valuable tool to identify high-risk IE patients when surgery is considered.

In infectious endocarditis patients mortality is highly related to kidney function at time of diagnosis: a prospective observational cohort study of 231 cases.

BACKGROUND: Infective endocarditis is a serious disease with a high mortality even with optimal treatment and care. A number of complicating conditions are known to be of importance for the outcome. But only few data are available in IE patients on the independent prognostic value of kidney function at the time of admittance. METHODS: In a prospective observational cohort study data from 235 consecutive IE patients were collected at 2 tertiary heart centres in Copenhagen. Kidney function was evaluated as Estimated Endogenous Creatinine Clearance (EECC) calculated at the time of admission. Patients were divided into 4 groups according to their EECC: 1) >90 ml/min, 2) 60-90 ml/min, 3) 30-60 ml/min and 4) <30 ml/min. Mortality statistical analysis was then applied. RESULTS: >Gender: 70.2% male, mean age: 61.3+/-SD 15.0. The most common pathogens were streptococcus species (32.9%) and Staphylococcus aureus (21.8%). Mean follow-up time was 453 days (SD 350). A total number of 76 patients died (32%), with an in-hospital mortality of 14%, and a post discharge mortality of 18%. In 64.9% EECC was decreased at time of admission, and a highly significant relationship between EECC and mortality was demonstrated, P<0.001. For every decrease of 10 ml/min in EECC we found an increase in Hazard Ratio for mortality of 23.1% (CI 13.2-33.8), P<0.001. CONCLUSION: Decreased kidney function is prevalent in patients with endocarditis. Calculated EECC at the time of admission is easily obtained in all IE patients and has a high and independent predictive prognostic value for mortality.