Contemporary epidemiology and outcomes in recurrent infective endocarditis

The Clinical Challenge of Prosthetic Valve Endocarditis: JACC Focus Seminar 3/4

During the past 6 decades, there have been numerous changes in prosthetic valve endocarditis (PVE), currently affecting an older population and increasing in incidence in patients with transcatheter-implanted valves. Significant microbiologic (molecular biology) and imaging diagnostic (fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography) advances have been incorporated into the 2023 Duke-International Society for Cardiovascular Infectious Diseases infective endocarditis diagnostic criteria, thus increasing the diagnostic sensitivity for PVE without sacrificing specificity in validation studies. PVE is a life-threatening disease requiring management by multidisciplinary endocarditis teams in cardiac centers to improve outcomes. Novel surgical options are now available, and an increasing set of patients may avoid surgical intervention despite indication. Selected patients may complete parenteral or oral antimicrobial treatment at home. Finally, patients with prosthetic valves implanted surgically or by the transcatheter approach are candidates for antibiotic prophylaxis before invasive dental procedures.

C-terminal deletion of RelA protein is suggested as a possible cause of infective endocarditis recurrence with Enterococcus faecium

Infective endocarditis (IE) caused by Enterococcus spp. represents the third most common cause of IE, with high rates of relapse compared with other bacteria. Interestingly, late relapses (>6 months) have only been described in Enterococcus faecalis, but here we describe the first reported IE relapse with Enterococcus faecium more than a year (17 months) after the initial endocarditis episode. Firstly, by multi locus sequence typing (MLST), we demonstrated that both isolates (EF646 and EF641) belong to the same sequence type (ST117). Considering that EF641 was able to overcome starvation and antibiotic treatment conditions surviving for a long period of time, we performed bioinformatic analysis in identifying potential genes involved in virulence and stringent response. Our results showed a 13-nucleotide duplication (positions 1638-1650) in the gene relA, resulting in a premature stop codon, with a loss of 167 amino acids from the C-terminal domains of the RelA enzyme. RelA mediates the stringent response in bacteria, modulating levels of the alarmone guanosine tetraphosphate (ppGpp). The relA mutant (EF641) was associated with lower growth capacity, the presence of small colony variants, and higher capacity to produce biofilms (compared with the strain EF646), but without differences in antimicrobial susceptibility patterns according to standard procedures during planktonic growth. Instead, EF641 demonstrated tolerance to high doses of teicoplanin when growing in a biofilm. We conclude that all these events would be closely related to the long-term survival of the E. faecium and the late relapse of the IE. These data represent the first clinical evidence of mutations in the stringent response (relA gene) related with E. faecium IE relapse.

Brain abscesses in infective endocarditis: contemporary profile and neuroradiological findings

BACKGROUND

Brain abscesses (BA) are severe lesions in the course of infective endocarditis (IE). We compare the bacteriological, clinical data, background, associated lesions, and outcome of IE patients with and without BAs, and assess the MRI characteristics of BAs.

METHODS

Retrospective study of 351 consecutive patients with definite IE (2005-2020) and at least one brain MRI. Patients with and without BAs were compared.

RESULTS

Twenty patients (5.7%) had BA (80% men; median age: 44.9 ± 11.5). They were younger (p = 0.035) and had a higher rate of predisposing factors (previous IE 20% vs 2.2%, p = 0.03), intravenous drug use [25% vs 2.2%; p < 0.0001]), underlying conditions (HIV infection, 20% vs 2.2%, p < 0.0001; alcohol abuse, 20% vs 2.2% p < 0.0001]; liver disease p = 0.04; hemodialysis, p = 0.001; type 2 diabetes, p = 0.001), bacterial meningitis (p = 0.0029), rare species involvement (35% vs 7%, p < 0.0006) and extra-cerebral abscesses (p = 0.0001) compared to patients without BA. Valve vegetations were larger in Group 1 (p = 0.046). Clinical presentation could suggest the diagnosis of BA in only 7/20 (35%) patients. MR identified 58 BAs (mean/patient 2.9; range 2-12): often multiple (80%), bilateral (55%) and ≤ 10 mm (72%). The presence of BA did not modify cardiac surgery indication and timing. Favorable outcome was observed in 85% of patients.

CONCLUSION

Rates of predisposing, underlying conditions, rare IE agents, meningitis and metastatic abscesses are significantly higher in BA-IE patients. As BAs can develop in asymptomatic IE patients, the impact of brain MRI on their management needs thoroughly to be further investigated.

Impact of the Duration of Postoperative Antibiotics on the Prognosis of Patients with Infective Endocarditis

Appropriate postoperative antibiotic treatment in patients with infective endocarditis (IE) reduces the risks of recurrence and mortality. However, concerns about adverse drug reactions arise due to prolonged antibiotic usage. Therefore, we compared the recurrence and mortality rates according to the duration of postoperative antibiotic therapy in patients with IE. From 2005 to 2017, we retrospectively reviewed 416 patients with IE treated at a tertiary hospital in South Korea; among these, 216 patients who underwent heart valve surgery and received appropriate antibiotics were enrolled. The patients were divided into two groups based on the duration of usage of postoperative antibiotic therapy; the duration of postoperative antibiotic therapy was more than two weeks in 156 patients (72.2%) and two weeks or less in 60 patients (27.8%). The primary endpoint was IE relapse. The secondary endpoints were 1-year IE recurrence, 1-year mortality, and postoperative complication rates. The median age was 53 (interquartile range: 38-62) years. The relapse rate of IE was 0.9% (2/216). There was no statistical difference in relapse (0.0% vs. 1.3%, p = 0.379), 1-year recurrence (1.7% vs. 1.3%, p = 0.829), or 1-year mortality (10.0% vs. 5.8%, p = 0.274) between patients with postoperative antibiotic administration of two weeks or less versus more than two weeks. The duration of postoperative antibiotic therapy did not affect the 1-year mortality rate (log-rank test, p = 0.393). In conclusion, there was no statistically significant difference in recurrence, mortality, or postoperative complications according to the duration of postoperative antibiotic therapy.

Clinical profile and outcome of recurrent infective endocarditis

AIMS

Purpose of this study is to compare the clinical course and outcome of patients with recurrent versus first-episode infective endocarditis (IE).

METHODS

Patients with recurrent and first-episode IE enrolled in the EUROpean ENDOcarditis (EURO-ENDO) registry including 156 centres were identified and compared using propensity score matching. Recurrent IE was classified as relapse when IE occurred ≤6 months after a previous episode or reinfection when IE occurred >6 months after the prior episode.

RESULTS

3106 patients were enrolled: 2839 (91.4%) patients with first-episode IE (mean age 59.4 (±18.1); 68.3% male) and 267 (8.6%) patients with recurrent IE (mean age 58.1 (±17.7); 74.9% male). Among patients with recurrent IE, 13.2% were intravenous drug users (IVDUs), 66.4% had a repaired or replaced valve with the tricuspid valve being more frequently involved compared with patients with first-episode IE (20.3% vs 14.1%; p=0.012). In patients with a first episode of IE, the aortic valve was more frequently involved (45.6% vs 39.5%; p=0.061). Recurrent relapse and reinfection were 20.6% and 79.4%, respectively. Staphylococcus aureus was the microorganism most frequently observed in both groups (p=0.207). There were no differences in in-hospital and post-hospitalisation mortality between recurrent and first-episode IE. In patients with recurrent IE, in-hospital mortality was higher in IVDU patients. Independent predictors of poorer in-hospital and 1-year outcome, including the occurrence of cardiogenic and septic shock, valvular disease severity and failure to undertake surgery when indicated, were similar for recurrent and first-episode IE.

CONCLUSIONS

In-hospital and 1-year mortality was similar in patients with recurrent and first-episode IE who shared similar predictors of poor outcome.

Anesthesia Considerations in Infective Endocarditis

The management of infective endocarditis is complex and inherently requires multidisciplinary cooperation. About half of all patients diagnosed with infective endocarditis will meet the criteria to undergo cardiac surgery, which regularly takes place in urgent or emergency settings. The pathophysiology and clinical presentation of infective endocarditis make it a unique disorder within cardiac surgery that warrants a thorough understanding of specific characteristics in the perioperative period. This includes, among others, echocardiography, coagulation, bleeding management, or treatment of organ dysfunction. In this narrative review article, the authors summarize the current knowledge on infective endocarditis relevant for the clinical anesthesiologist in perioperative management of respective patients. Furthermore, the authors advocate for the anesthesiologist to become a structural member of the endocarditis team.

Clinical outcomes of percutaneous debulking of tricuspid valve endocarditis in intravenous drug users

OBJECTIVES

A retrospective case series of a percutaneous approach to debulk tricuspid valve endocarditis (TVE) using an 8 French mechanical aspiration system in patients with a history of intravenous drug use (IVDU) was reported. IVDU associated TVE is increasing in the United States and is associated with high mortality despite early surgical debridement. Patients with advanced disease, shock, and respiratory failure may not be candidates for surgical debridement or replacement. These patients have recurrent events despite medical therapy METHODS: About 25 patients with IVDU associated TVE with persistent bacteremia confirmed by repeat blood cultures after 72 hr of sensitivity directed antibiotics and presence of pulmonary emboli confirmed by computed tomographic (CT) scan, who had undergone percutaneous aspiration were included. Patients were all deemed high risk for surgical debridement by a CT surgeon and evaluated by an infectious disease consultant. Procedures were performed under moderate sedation with intracardiac echo and a steerable guide with a CAT8 Penumbra aspiration catheter.

RESULTS

There were no intraprocedural deaths or complications. About 36% had septic shock on presentation. Survival of index hospitalization was 88%. Repeat blood cultures showed no growth on all surviving patients. Readmission rate was 4% (n = 1) at 1 month. About 40% (n = 2) patients with septic shock survived at 1 month compared with 100% survival (n = 20) in those without shock. Presence of septic shock was associated with reduced survival at 1 month (p < .01).

CONCLUSION

Percutaneous mechanical aspiration with an 8 Fr system is a feasible, minimally invasive alternative to surgical debulking. Mortality remains high in those presenting with septic shock. Further studies are needed to evaluate long-term outcomes.

Transcatheter Aortic Valve Replacement for Residual Lesion of the Aortic Valve Following "Healed" Infective Endocarditis

OBJECTIVES

This study aimed to evaluate the safety and mid-term efficacy of transcatheter aortic valve replacement (TAVR) in the setting of aortic valve (AV) infective endocarditis (IE) with residual lesion despite successful antibiotic treatment.

BACKGROUND

Patients with AV-IE presenting residual lesion despite successful antibiotic treatment are often rejected for cardiac surgery due to high-risk. The use of TAVR following IE is not recommended.

METHODS

This was a multicenter retrospective study across 10 centers, gathering baseline, in-hospital, and 1-year follow-up characteristics of patients with healed AV-IE treated with TAVR. Matched comparison according to sex, EuroSCORE, chronic kidney disease, left ventricular function, prosthesis type, and valve-in-valve procedure was performed with a cohort of patients free of prior IE treated with TAVR (46 pairs).

RESULTS

Among 2,920 patients treated with TAVR, 54 (1.8%) presented with prior AV-IE with residual valvular lesion and healed infection. They had a higher rate of multivalvular disease and greater surgical risk scores. A previous valvular prosthesis was more frequent than a native valve (50% vs. 7.5%; p < 0.001). The in-hospital and 1-year mortality rates were 5.6% and 11.1%, respectively, comparable to the control cohort. After matching, the 1-year III to IV aortic regurgitation rate was 27.9% (vs. 10%; p = 0.08) and was independently associated with higher mortality. There was only 1 case of IE relapse (1.8%); however, 18% of patients were complicated with sepsis, and 43% were readmitted due to heart failure.

CONCLUSIONS

TAVR is a safe therapeutic alternative for residual valvular lesion after successfully healed AV-IE. At 1-year follow-up, the risk of IE relapse was low and mortality rate did not differ from TAVR patients free of prior IE, but one-fourth presented with significant aortic regurgitation and >50% required re-admission.

Clinical Factors Associated with Reinfection versus Relapse in Infective Endocarditis: Prospective Cohort Study

We aimed to identify clinical factors associated with recurrent infective endocarditis (IE) episodes. The clinical characteristics of 2816 consecutive patients with definite IE (January 2008–2018) were compared according to the development of a second episode of IE. A total of 2152 out of 2282 (94.3%) patients, who were discharged alive and followed-up for at least the first year, presented a single episode of IE, whereas 130 patients (5.7%) presented a recurrence; 70 cases (53.8%) were due to other microorganisms (reinfection), and 60 cases (46.2%) were due to the same microorganism causing the first episode. Thirty-eight patients (29.2%), whose recurrence was due to the same microorganism, were diagnosed during the first 6 months of follow-up and were considered relapses. Relapses were associated with nosocomial endocarditis (OR: 2.67 (95% CI: 1.37–5.29)), enterococci (OR: 3.01 (95% CI: 1.51–6.01)), persistent bacteremia (OR: 2.37 (95% CI: 1.05–5.36)), and surgical treatment (OR: 0.23 (0.1–0.53)). On the other hand, episodes of reinfection were more common in patients with chronic liver disease (OR: 3.1 (95% CI: 1.65–5.83)) and prosthetic endocarditis (OR: 1.71 (95% CI: 1.04–2.82)). The clinical factors associated with reinfection and relapse in patients with IE appear to be different. A better understanding of these factors would allow the development of more effective therapeutic strategies.

Porphyromonas gingivalis disrupts vascular endothelial homeostasis in a TLR-NF-κB axis dependent manner

Cardiovascular disease is still the leading cause of mortality worldwide. Vascular endothelial dysfunction is viewed as the initial step of most cardiovascular diseases. Many studies have indicated that periodontal pathogens, especially Porphyromonas gingivalis, are closely correlated with vascular endothelial homeostasis, but the function of P. gingivalis and the underlying mechanisms are still elusive. To illuminate the effects and elucidate the mechanisms of P. gingivalis on endothelial structural integrity, we developed P. gingivalis infection models in vivo and in vitro. Endothelial cell proliferation, differentiation and apoptosis were detected. Here, we showed that P. gingivalis can impair endothelial integrity by inhibiting cell proliferation and inducing endothelial mesenchymal transformation and apoptosis of endothelial cells, which reduce the cell levels and cause the endothelium to lose its ability to repair itself. A mechanistic analysis showed that TLR antagonist or NF-κB signalling inhibitor can largely rescue the damaged integrity of the endothelium caused by P. gingivalis, suggesting that TLR-NF-κB signalling plays a vital role in vascular endothelial homeostasis destroyed by P. gingivalis. These results suggest a potential intervention method for the prevention and treatment of cardiovascular disease.

Short-course antibiotic regimen compared to conventional antibiotic treatment for gram-positive cocci infective endocarditis: randomized clinical trial (SATIE)

Background

Most serious complications of infective endocarditis (IE) appear in the so-called “critical phase” of the disease, which represents the first days after diagnosis. The majority of patients overcoming the acute phase has a favorable outcome, yet they remain hospitalized for a long period of time mainly to complete antibiotic therapy. The major hypothesis of this trial is that in patients with clinically stable IE and adequate response to antibiotic treatment, without signs of persistent infection, periannular complications or metastatic foci, a shorter antibiotic time period would be as efficient and safe as the classic 4 to 6 weeks antibiotic regimen.

Methods

Multicenter, prospective, randomized, controlled open-label, phase IV clinical trial with a non-inferiority design to evaluate the efficacy of a short course (2 weeks) of parenteral antibiotic therapy compared with conventional antibiotic therapy (4–6 weeks).

Sample: patients with IE caused by gram-positive cocci, having received at least 10 days of conventional antibiotic treatment, and at least 7 days after surgery when indicated, without clinical, analytical, microbiological or echocardiographic signs of persistent infection. Estimated sample size: 298 patients. Intervention: Control group: standard duration antibiotic therapy, (4 to 6 weeks) according to ESC guidelines recommendations. Experimental group: short-course antibiotic therapy for 2 weeks. The incidence of the primary composite endpoint of all-cause mortality, unplanned cardiac surgery, symptomatic embolisms and relapses within 6 months after the inclusion in the study will be prospectively registered and compared.

Conclusions

SATIE will investigate whether a two weeks short-course of intravenous antibiotics in patients with IE caused by gram-positive cocci, without signs of persistent infection, is not inferior in safety and efficacy to conventional antibiotic treatment (4–6 weeks).

Trial registration

ClinicalTrials.gov Identifier: NCT04222257 (January 7, 2020).

EudraCT 2019–003358-10.