Comparison of prognoses of Staphylococcus aureus left-sided prosthetic endocarditis and prosthetic endocarditis caused by other pathogens

Clinical characteristics and analysis of prognostic factors in methicillin-resistant Staphylococcus aureus endocarditis: A retrospective multicenter study in Japan

BACKGROUND

Infective endocarditis (IE) caused by MRSA (methicillin-resistant Staphylococcus aureus) is associated with a high mortality rate. This study aimed to elucidate the characteristics of patients with MRSA-IE in Japan and identify the factors associated with prognosis.

METHODS

This retrospective study included patients with a confirmed diagnosis of IE caused by MRSA, between January 2015 and April 2019.

RESULTS

A total of 65 patients from 19 centers were included, with a mean age of 67 years and 26 % were female. Fifty percent of the patients with IE were had nosocomial infections and 25 % had prosthetic valve involvement. The most common comorbidities were hemodialysis (20 %) and diabetes (20 %). Congestive heart failure was present in 86 % of patients (NYHA class I, II: 48 %; III, IV: 38 %). The 30-day and in-hospital mortality rates were 29 % and 46 %, respectively. Multi-organ failure was the primary cause of death, accounting for 43 % of all causes of death. Prognostic factors for in-hospital mortality were age, disseminated intravascular coagulation, daptomycin and/or linezolid as initial antibiotic therapy, and surgery. Surgical treatment was associated with a lower mortality rate (odds ratio [OR], 0.026; 95 % confidence interval [CI], 0.002-0.382; p = 0.008 for 30-day mortality and OR, 0.130; 95 % CI; 0.029-0.584; p = 0.008 for in-hospital mortality).

CONCLUSION

Mortality due to MRSA-IE remains high. Surgical treatment is a significant prognostic predictor of MRSA-IE.

Clinical features and prognosis of prosthetic valve endocarditis due to Staphylococcus aureus

PURPOSE

Staphylococcus aureus prosthetic valve endocarditis (SAPVE) is a serious infection with high mortality. The main objective of this study was to identify factors associated with in-hospital mortality.

METHODS

From January 2008 to December 2021, consecutive patients from a Spanish cohort of infective endocarditis with a definitive diagnosis of SAPVE were analyzed.

RESULTS

During the study period, 219 cases of definitive SAPVE were diagnosed, which accounted for 16.7% of a total of 1309 cases of definitive prosthetic valve endocarditis (PVE). Patients presented advanced age and marked comorbidity. There was a higher incidence of persistent bacteremia, septic shock, stroke, and acute kidney injury than in cases of PVE caused by other microorganisms. Methicillin resistance was not associated with differences in clinical presentation, echocardiographic findings, or mortality. Only 50.6% of the patients with surgical indications (88 patients) underwent surgery. Overall, in-hospital mortality was 47.9%. The variables associated with in-hospital mortality were age (OR:1.03, 95% CI: 1.00-1.05; p = 0.016), heart failure (OR:2.86, 95% CI: 1.53-5.32; p = 0.001), acute kidney injury (OR:2.42, 95%CI:1.28-4.58; p = 0.006), stroke (OR:3.53, 95%CI:1.79-6.96; p < 0.001) and surgery indicated but not performed (OR:2.01, 95%CI:1.06-3.8; p = 0.030). On the other hand, the performance of surgery per se in patients with SAPVE, regardless of whether there was a surgical indication according to the guidelines, was not associated with a reduction in in-hospital mortality.

CONCLUSIONS

SAPVE is characterized by high mortality, which is more marked in patients who present a surgical indication but do not undergo surgery.

Emerging and Re-Emerging Pathogens in Valvular Infective Endocarditis: A Review

Infective endocarditis (IE) is a microbial infection of the endocardial surface, most commonly affecting native and prosthetic valves of the heart. The epidemiology and etiology of the disease have evolved significantly over the last decades. With a growing elderly population, the incidence of degenerative valvopathies and the use of prosthetic heart valves have increased, becoming the most important predisposing risk factors. This change in the epidemiology has caused a shift in the underlying microbiology of the disease, with Staphylococci overtaking Streptococci as the main causative pathogens. Other rarer microbes, including Streptococcus agalactiae, Pseudomonas aeruginosa, Coxiella burnetti and Brucella, have also emerged or re-emerged. Valvular IE caused by these pathogens, especially Staphylococcus aureus, is often associated with a severe clinical course, leading to high rates of morbidity and mortality. Therefore, prompt diagnosis and management are crucial. Due to the high virulence of these pathogens and an increased incidence of antimicrobial resistances, surgical valve repair or replacement is often necessary. As the epidemiology and etiology of valvular IE continue to evolve, the diagnostic methods and therapies need to be progressively advanced to ensure satisfactory clinical outcomes.

Staphylococcus aureus endocarditis: Identifying prognostic factors using a method derived from morbidity and mortality conferences

Objectives

Lethality of Staphylococcus aureus (Sa) infective endocarditis (IE) is high and might be due to yet unidentified prognostic factors. The aim of this study was to search for new potential prognostic factors and assess their prognostic value in SaIE.

Materials and methods

We used a two-step exploratory approach. First, using a qualitative approach derived from mortality and morbidity conferences, we conducted a review of the medical records of 30 patients with SaIE (15 deceased and 15 survivors), randomly extracted from an IE cohort database (NCT03295045), to detect new factors of possible prognostic interest. Second, we collected quantitative data for these factors in the entire set of SaIE patients and used multivariate Cox models to estimate their prognostic value.

Results

A total of 134 patients with modified Duke definite SaIE were included, 64 of whom died during follow-up. Of the 56 candidate prognostic factors identified at the first step, 3 had a significant prognostic value in multivariate analysis: the prior use of non-steroidal anti-inflammatory drugs [aHR 3.60, 95% CI (1.59-8.15), p = 0.002]; the non-performance of valve surgery when indicated [aHR 1.85, 95% CI (1.01-3.39), p = 0.046]; and the decrease of vegetation size on antibiotic treatment [aHR 0.34, 95% CI (0.12-0.97), p = 0.044].

Conclusion

We identified three potential SaIE prognostic factors. These results, if externally validated, might eventually help improve the management of patients with SaIE.

Novel human in vitro vegetation simulation model for infective endocarditis

Infective endocarditis (IE) is a heart valve infection with high mortality rates. IE results from epithelial lesions, inducing sterile healing vegetations consisting of platelets, leucocytes, and fibrin that are susceptible for colonization by temporary bacteremia. Clinical testing of new treatments for IE is difficult and fast models sparse. The present study aimed at establishing an in vitro vegetation simulation IE model for fast screening of novel treatment strategies. A healing promoting platelet and leucocyte-rich fibrin patch was used to establish an IE organoid-like model by colonization with IE-associated bacterial isolates Staphylococcus aureus, Streptococcus spp (S. mitis group), and Enterococcus faecalis. The patch was subsequently exposed to tobramycin, ciprofloxacin, or penicillin. Bacterial colonization was evaluated by microscopy and quantitative bacteriology. We achieved stable bacterial colonization on the patch, comparable to clinical IE vegetations. Microscopy revealed uneven, biofilm-like colonization of the patch. The surface-associated bacteria displayed increased tolerance to antibiotics compared to planktonic bacteria. The present study succeeded in establishing an IE simulation model with the relevant pathogens S. aureus, S. mitis group, and E. faecalis. The findings indicate that the IE model mirrors the natural IE process and has the potential for fast screening of treatment candidates.

Predictors of mortality and adverse events in patients with infective endocarditis: a retrospective real world study in a surgical centre

Purpose

Mortality in infective endocarditis (IE) is still high, and the long term prognosis remains uncertain. This study aimed to identify predictors of long-term mortality for any cause, adverse event rate, relapse rate, valvular and ventricular dysfunction at follow-up, in a real-world surgical centre.

Methods

We retrospectively analyzed 363 consecutive episodes of IE (123 women, 34%) admitted to our department with a definite diagnosis of non-device-related IE. Median follow-up duration was 2.9 years. Primary endpoints were predictors of mortality, recurrent endocarditis, and major non-fatal adverse events (hospitalization for any cardiovascular cause, pace-maker implantation, new onset of atrial fibrillation, sternal dehiscence), and ventricular and valvular dysfunction at follow-up.

Results

Multivariate analysis independent predictors of mortality showed age (HR per unit 1.031, p < 0.003), drug abuse (HR 3.5, p < 0.002), EUROSCORE II (HR per unit 1.017, p < 0.0006) and double valve infection (HR 2.3, p < 0.001) to be independent predictors of mortality, while streptococcal infection remained associated with a better prognosis (HR 0.5, p < 0.04). Major non-fatal adverse events were associated with age (HR 1.4, p < 0.022). New episodes of infection were correlated with S aureus infection (HR 4.8, p < 0.001), right-sided endocarditis (HR 7.4, p < 0.001), spondylodiscitis (HR 6.8, p < 0.004) and intravenous drug abuse (HR 10.3, p < 0.001). After multivariate analysis, only drug abuse was an independent predictor of new episodes of endocarditis (HR 8.5, p < 0.001). Echocardiographic follow-up, available in 95 cases, showed a worsening of left ventricular systolic function (p < 0.007); severe valvular dysfunction at follow-up was reported only in 4 patients, all of them had mitral IE (p < 0.03).

Conclusions

The present study highlights some clinical, readily available factors that can be useful to stratify the prognosis of patients with IE.

Characteristics and Prognosis of Patients With Left-Sided Native Bivalvular Infective Endocarditis

BACKGROUND

Most cases of left-sided native valve infective endocarditis (IE) involve a single valve and little is known concerning IE that simultaneously affects the aortic and mitral valves.

METHODS

We aimed to determine the characteristics, identify the prognostic factors, and define the effect of early surgery for patients with left-sided native bivalvular IE. This analysis included 1340 consecutive patients who presented with definite acute left-sided native valve IE in a 2-centre cohort study.

RESULTS

A bivalvular involvement was present in 257 patients (19%). Patients with bivalvular IE had more embolic events (P = 0.044), congestive heart failure (P = 0.016), vegetations, and perivalvular complications (both P < 0.001) than those with monovalvular IE. Early surgery was more frequent for patients with bivalvular IE (P < 0.001). Thirty-day mortality was higher for patients with bivalvular IE than for those with monovalvular IE (24.5% vs 17.6%; P = 0.008), even after adjustment (odds ratio, 1.86 [95% confidence interval, 1.26-2.73]; P < 0.001). Estimated 10-year survival was 70% ± 1% for monovalvular IE and 59% ± 3% for bivalvular IE (P = 0.002). Bivalvular IE was still associated with mortality in multivariable Cox analysis, after adjustment for covariates including age, neurological events, congestive heart failure, Staphylococcus spp infection, perivalvular complications, and early surgery (hazard ratio, 1.70 [95% confidence interval, 1.31-2.11]; P < 0.001). Early surgery was associated with increased survival for patients with bivalvular IE (79% ± 4% vs 35% ± 6%; P < 0.001).

CONCLUSIONS

Bivalvular involvement is frequent in left-sided native valve IE, is associated with more embolic events and congestive heart failure than monovalvular IE, and patients are at a high risk of death. Early surgery is associated with improved survival and should be systematically discussed in the absence of contraindication.

Short- and Long-term Outcomes of Medically Treated Isolated Left-Sided Endocarditis: A Retrospective Study With 5-Year Longitudinal Follow-up

BACKGROUND

A retrospective study of medically treated isolated left-sided infective endocarditis (LSIE) patients identifying predictors of outcomes with nonoperative management was undertaken.

METHODS

Medical records of 135 Manitoban medically managed LSIE patients from January 2004 to December 2016 were reviewed. Five-year survival for 135 patients and hospitalization data till March 2016 for 65 patients were collected from the Manitoba Centre for Health Policy.

RESULTS

In-hospital mortality was 44%. Patients with surgical indications were more likely to die in-hospital than those without (53% vs 24%; P = 0.002). Survival at 1 and 5 years was 43% and 23%, respectively. All-cause readmission at 1 and 5 years was 64% and 84%, respectively. At 1 and 5 years, readmission from major adverse events (heart failure, stroke, endocarditis) was 25% and 47%, and from recurrent endocarditis was 17% and 26%, respectively. Severe valvular regurgitation was a risk factor for in-hospital mortality (odds ratio, 3.52; P = 0.022), poor long-term survival (hazard ratio [HR], 2.57; P < 0.001), and recurrent endocarditis (HR, 5.93; P < 0.001). Prosthetic valve endocarditis was a risk factor for poor long-term survival (HR, 2.11; P = 0.002). Streptococcus viridans group was associated with better rates of in-hospital mortality (odds ratio, 0.28; P = 0.018) and long-term survival (HR, 0.34; P < 0.001).

CONCLUSIONS

Nonoperative management of LSIE carries a poor prognosis but may have a role in select cases. Surgical management remains the mainstay for patients with clear surgical indications, including severe regurgitation and prosthetic valve endocarditis. Further prospective analyses are required to better delineate appropriate patient selection for nonsurgical management.

Infective endocarditis: innovations in the management of an old disease

The annual incidence of infective endocarditis (IE) is estimated to be between 15 and 80 cases per million persons in population-based studies. The incidence of IE is markedly increased in patients with valve prostheses (>4 per 1,000) or with prior IE (>10 per 1,000). The interaction between platelets, microorganisms and diseased valvular endothelium is the cause of vegetations and valvular or perivalvular tissue destruction. Owing to its complexity, the diagnosis of IE is facilitated by the use of the standardized Duke-Li classification, which combines two major criteria (microbiology and imaging) with five minor criteria. However, the sensitivity of the Duke-Li classification is suboptimal, particularly in prosthetic IE, and can be improved by the use of PET or radiolabelled leukocyte scintigraphy. Prolonged antibiotic therapy is mandatory. Indications for surgery during acute IE depend on the presence of haemodynamic, septic and embolic complications. The most urgent indications for surgery are related to heart failure. In the past decade, the prevention of IE has been reoriented, with indications for antibiotic prophylaxis now limited to patients at high risk of IE undergoing dental procedures. Guidelines now emphasize the importance of nonspecific oral and cutaneous hygiene in individual patients and during health-care procedures.

High-dose trimethoprim-sulfamethoxazole and clindamycin for Staphylococcus aureus endocarditis

OBJECTIVE

The mortality rate for Staphylococcus aureus endocarditis remains as high as 20-30% despite improvements in medical and surgical treatment. This study evaluated the efficiency and tolerance of a combination of intravenous trimethoprim-sulfamethoxazole and clindamycin (T&C) +/- rifampicin and gentamicin, with a rapid switch to oral administration of T&C.

METHODS

This before-after intervention study compared the outcomes of 170 control patients before introduction of the T&C protocol (2001-2011) with the outcomes of 171 patients in the T&C group (2012-2016). All patients diagnosed with S. aureus infective endocarditis and referred to the study centre between 2001 and 2016 were included. Between 2001 and 2011, the patients received a standardized antibiotic treatment: oxacillin or vancomycin for 6 weeks, plus gentamicin for 5 days. Since February 2012, the antibiotic protocol has included a high dose of T&C (intravenous, switched to oral administration on day 7). Rifampicin and gentamicin are also given in cases of cardiac abscess or persistent bacteraemia.

RESULTS

The two groups were slightly different. On intention-to-treat analysis, global mortality (19% vs 30%, P=0.024), in-hospital mortality (10% vs 18%, P=0.03) and 30-day mortality (7% vs 14%, P=0.05) were lower in the T&C group. The mean duration of hospital stay was significantly shorter in the T&C group (30 vs 39 days; P=0.005).

CONCLUSIONS

The management of S. aureus infective endocarditis using a rapid shift to oral administration of T&C reduced the length of hospital stay and the mortality rate.

Gentamicin may have no effect on mortality of staphylococcal prosthetic valve endocarditis

PURPOSE

To analyze the influence of adding gentamicin to a regimen consisting of β-lactam or vancomycin plus rifampicin on survival in patients suffering from Staphylococcal prosthetic valve endocarditis (SPVE).

METHODS

From January 2008 to September 2016, 334 patients with definite SPVE were attended in the participating hospitals. Ninety-four patients (28.1%) received treatment based on β-lactam or vancomycin plus rifampicin and were included in the study. Variables were analyzed which related to patient survival during admission, including having received treatment with gentamicin.

RESULTS

Seventy-seven (81.9%) were treated with cloxacillin (or vancomycin) plus rifampicin plus gentamicin, and 17 patients (18.1%) received the same regimen without gentamicin. The causative microorganism was Staphylococcus aureus in 40 cases (42.6%) and coagulase-negative staphylococci in 54 cases (57.4%). Overall, 40 patients (42.6%) died during hospital admission, 33 patients (42.9%) in the group receiving gentamicin and 7 patients in the group that did not (41.2%, P = 0.899). Worsening renal function was observed in 42 patients (54.5%) who received gentamicin and in 9 patients (52.9%) who did not (p = 0.904). Heart failure as a complication of endocarditis (OR: 4.58; CI 95%: 1.84-11.42) and not performing surgery when indicated (OR: 2.68; CI 95%: 1.03-6.94) increased mortality. Gentamicin administration remained unrelated to mortality (OR: 1.001; CI 95%: 0.29-3.38) in the multivariable analysis.

CONCLUSIONS

The addition of gentamicin to a regimen containing vancomycin or cloxacillin plus rifampicin in SPVE was not associated to better outcome.