Infective endocarditis in the setting of renal transplantation: Case report and review of the literature

Contemporary Outcomes and Predictors of Inpatient Mortality for Infective Endocarditis Occurring in Renal Transplant Recipients in the United States

Renal transplant (RT) recipients are susceptible to infections because of immunosuppression. The literature regarding the epidemiology and outcomes of infective endocarditis (IE) in RT recipients is limited. We analyzed the National Inpatient Sample in the United States to study IE in RT and identify risk factors for inpatient mortality and IE development in RT patients. All patients ≥18 years who had IE with and without RT between 2007 and 2019 were identified from the National Inpatient Sample. The demographics, co-morbidities, length of stay, hospital costs, and mortality of IE patients with RT were compared with IE patients without RT. Predictors of inpatient mortality for RT recipients with IE were analyzed. Between 2007 and 2019, there were 777,245 hospitalizations for IE, of which 3,782 had RT. The IE in RT cohort was younger than the general IE population and had higher proportions of males, non-White races, and Hispanic ethnicity, and higher burden of co-morbidities, but similar inpatient mortality rates. On multivariate analysis, Staphylococcal IE (adjusted odds ratio [aOR] 2.26, 95% confidence interval [CI] 1.2 to 4.3, p = 0.015), stroke (aOR 6.4, 95% CI 2.7 to 15.3, p <0.001), anemia (aOR 2.3, 95% CI 1.3 to 4.0, p = 0.004), and shock (aOR 6.3, 95% CI 3.3 to 11.9, p <0.001) were associated with greater inpatient mortality, whereas Streptococcal endocarditis (aOR 0.37, 95% CI 0.1 to 0.9, p = 0.038) was associated with lower inpatient mortality. In conclusion, RT patients with IE were younger and had more severe co-morbidities compared with IE patients without RT. Staphylococcal IE, presence of shock and stroke worsened the prognosis in these patients.

Corynebacterium striatum Endocarditis After Renal Transplantation Confirmed by Metagenomic Next-Generation Sequencing: Case Report and Literature Review

Background

Case Presentation

Conclusion

Infective endocarditis in solid organ transplant: a review

PURPOSE OF REVIEW

Infective endocarditis remains an uncommon disease with significant morbidity and mortality. In the last two decades, progress has been made describing the unique aspects of infective endocarditis in solid organ transplant (SOT) recipients.

RECENT FINDINGS

Incidence of infective endocarditis in SOT is higher when compared with the general population. End-stage organ dysfunction, diabetes mellitus, older age, and prior intravenous lines have been identified as risk factors predisposing to infective endocarditis in SOT. Staphylococci and enterococci represent the most frequently isolated pathogens, whereas fungi are rarely isolated. Median time from transplantation to diagnosis ranges from 33 to 66 months. Nosocomial acquisition and mural endocarditis are more common in SOT recipients with infective endocarditis. Procurement of organs from patients with infective endocarditis might be well tolerated so long as close monitoring and targeted antibiotics are given. Selected patients might benefit from heart transplantation as definitive or salvage therapy for infective endocarditis. Outcomes of infective endocarditis in SOT recipients compared with the general population might be similar; however, patient survival and graft function are reduced when recipients suffer from infective endocarditis.

SUMMARY

Infective endocarditis although rare can affect donors and recipients involved in the SOT process. Recognition of the unique characteristics in the presentation, prevention, medical, and surgical therapy of this disease is essential in order to minimize adverse outcomes.

In-hospital mortality and length of stay among patients with infective endocarditis and solid organ transplant: A study from National Inpatient Sample 2016-2019

Infective endocarditis (IE) is a rare but serious complication following a Solid Organ Transplant (SOT). Due to the lack of sufficient studies, we aimed to compare in-hospital mortality and length of stay (LOS) of patients primarily admitted for IE (index or principal hospitalization) with history of SOT, including the subgroup of heart or lung transplant (HLT), to those without a history of SOT (non-SOT) or HLT (non-HLT). We used the 2016–2019 National Inpatient Sample, the largest all-payer inpatient hospital data from Healthcare Cost and Utilization Project (HCUP), including patients 18 years or older with IE, as a principal diagnosis for hospitalization. From 2016 to 2019, there were 56,330 principal or index hospitalizations for IE. Among them, 0.6 % (n = 327) were SOT recipients, 0.1% (n = 68) were HLT recipients, and 41.4% were females. The mean age was 51.9 ± 19.2 years. Compared to non-SOT controls, SOT recipients were older (mean age 59.3 vs. 51.8 years; P = 0.002) and had higher Charlson-comorbidity-index (CCI) of 3 or more (87.7% vs. 33.2%; p < 0.001). SOT status was not statistically significant for a higher or lower odds of in-hospital mortality (adjusted odds ratio (aOR) 0.7; 95% confidence interval (CI): 0.2, 2.4; p = 0.60) or increased or decreased LOS (coefficient: -0.1, 95% CI: -0.4, 0.1; p = 0.23) among index IE hospitalizations after controlling for age, sex, race, hospital-region, hospital-teaching status, income, insurance status, and CCI. HLT status was also not associated with higher or lower odds of in-hospital mortality (aOR 1.4; 95% CI: 0.2, 13.1; p = 0.77) or increased or decreased LOS (coefficient: -0.1, 95% CI: -0.3, 0.5; p = 0.59). From 2016 to 2019, the rate of index IE hospitalization trends from 37.8 to 41.4 per 100,000 overall hospitalizations (p = 0.001). We found the rate of index IE hospitalizations increasing with time. Among index IE hospitalizations, SOT, including a subgroup of HLT recipients, have similar in-hospital mortality and LOS compared to non-SOT or non-HLT groups. We need a larger sample size to comment on outcomes of IE hospitalizations with the HLT subgroup.

Infective endocarditis and solid organ transplantation: Only worse outcomes during initial transplantation hospitalization

BACKGROUND

The epidemiology, and outcome of infective endocarditis (IE) among solid organ transplant (SOT) recipients is unknown.

METHODS

We used data from the 2013-2018 Nationwide Readmissions Database (NRD). IE- and SOT-associated hospitalizations were identified using diagnosis and procedure codes. Outcomes included inpatient mortality, length of stay, and inpatient costs. Adjusted analyses were performed using weighted regression models.

RESULTS

A total of 99,052 IE-associated hospitalizations, corresponding to a weighted national estimate of 193,164, were included for analysis. Of these, 794 (weighted n = 1,574) were associated with transplant history (SOT-IE). Mortality was not significantly different between SOT-IE and non-SOT-IE (17.2% vs. 15.8%, adjusted relative risk [aRR]: 0.86, 95% confidence interval [CI] [0.71, 1.03]), and fewer SOT-IE patients underwent valve repair or replacement than non-SOT-IE (12.5% vs. 16.2%, aRR 0.82, 95% CI [0.71, 0.95]). We then compared outcomes of patients diagnosed with IE during their index transplant hospitalization (index-SOT-IE) to patients without IE during their transplant hospitalization (index-SOT). Index-SOT-IE occurred most frequently among heart transplant recipients (45.1%), and was associated with greater mortality (27.1% vs. 2.3%, aRR 6.07, 95% CI [3.32, 11.11]).

CONCLUSION

Dual diagnosis of SOT and IE was associated with worse outcomes among SOT recipients during index hospitalization, but not overall among patients with IE.

High Mortality and Graft Loss after Infective Endocarditis in Kidney Transplant Recipients: A Case-Controlled Study from Two Centers

Kidney transplant recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation, and outcome. While infective endocarditis (IE) is among such complications in KTRs, the literature is scarce. We describe the presentation, epidemiology, and factors associated with IE in KTRs. We performed a retrospective case/control study which included patients from two centers. First episodes of definite or possible IE (Duke criteria) in adult KTRs from January 2010 to December 2018 were included, as well as two controls per case, and followed until 31 December 2019. Clinical, biological, and microbiological data and the outcome were collected. Survival was studied using the Kaplan-Meier method. Finally, we searched for factors associated with the onset of IE in KTRs by the comparison of cases and controls. Seventeen cases and 34 controls were included. IE was diagnosed after a mean delay of 78 months after KT, mostly on native valves of the left heart only. Pathogens of digestive origin were most frequently involved (six Enterococcus spp, three Streptococcus gallolyticus, and one Escherichia coli), followed by Staphylococci (three cases of S. aureus and S. epidermidis each). Among the risk factors evaluated, age, vascular nephropathy, and elevated calcineurin inhibitor through levels were significantly associated with the occurrence of IE in our study. Patient and death-censored graft survival were greatly diminished five years after IE, compared to controls being 50.3% vs. 80.6% (p < 0.003) and 29.7% vs. 87.5% (p < 0.002), respectively. IE in KTRs is a disease that carries significant risks both for the survival of the patient and the transplant.

Infective endocarditis by Klebsiella species: a systematic review

This study aimed to systematically analyze all cases of infective endocarditis (IE) by Klebsiella species in the literature. A systematic review of PubMed, Scopus and Cochrane library (through 27^th January 2021) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of IE by Klebsiella species was performed. In this review, a total of 66 studies were included, providing data for 67 patients. A prosthetic valve was present in 16.4%, while the most common causative pathogen was K. pneumoniae followed by K. oxytoca. The aortic valve was the most commonly infected intracardiac site, followed by the mitral valve. The diagnosis was based on transthoracic echocardiography in 46.2%, while the diagnosis was set at autopsy in 9.2% of included patients. Blood cultures were positive in 93.8%. Fever and sepsis were the most frequent clinical presentations, followed by embolic phenomena, paravalvular abscess, and heart failure. Cephalosporins, aminoglycosides, and carbapenems were the most frequently used antimicrobials. Surgical treatment along with antimicrobials was performed in 37.3% of included patients. Clinical cure was noted in 80.3%, while the overall mortality was 19.4%. Infection at the aortic valve was independently associated with mortality by IE. This systematic review gives a comprehensive description of IE by Klebsiella and provides information on epidemiology, clinical manifestations, therapeutic strategies and their outcomes.

FDG PET/CT for Detection of Infectious Complications Following Solid Organ Transplantation

Infectious complications after solid organ transplantation (SOT) are often more severe and remain a diagnostic challenge due to vague and atypical clinical presentations. Diagnostic performance of conventional diagnostic tools is frequently inadequate which may lead to delayed diagnosis with the risk of poorer outcomes. This literature review aimed to investigate the current evidence on the use of ¹⁸F-fluoro-deoxy-glucose (FDG) Positron Emission Tomography (PET)/computer tomography (CT) in infectious complications after SOT. Based on search in PubMed, Medline, and Cochrane databases, 13 articles and 46 case reports were included. For inclusion, articles were to include data on patients with infectious complications after SOT, and where FDG PET/CT was part of the work-up. Final searches were conducted on 02 September 2020. Overall, in the absence of initial diagnostic clues, FDG PET/CT should be considered as the imaging technique of choice as it may guide further investigations and eventually reveal the diagnosis in most of the patients. However, the available literature of the role of FDG PET/CT in SOT recipients with infectious complications is scarce and well-designed prospective studies including control groups are warranted to establish the role of FDG PET/C/ in SOT recipients. The main drawback of FDG PET/CT is the lack of ability to differentiate between cancer and infectious diseases which are both highly prevalent in this patient group. Accordingly, the main reasons for "false" results of FDG PET/CT is the misdiagnosis of cancer in benign inflammatory or infectious processes, information which nonetheless can be useful.

Endocarditis in kidney transplant recipients: a systematic review

Infective Endocarditis (IE) carries significant mortality. Bacteremia, which is a predisposing factor for IE, occurs more frequently in immunocompromised individuals. Interestingly, IE in kidney transplant recipients has not been adequately described. The aim of this study was to systematically review all published cases of IE in kidney transplant recipients and describe their epidemiology, microbiology, clinical characteristics, treatment and outcomes. A systematic review of PubMed (through 13^th December 2019) for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of IE in kidney transplant recipients was performed. A total of 60 studies, containing data of 117 patients, were included in the analysis. The most common causative pathogens were gram-positive microorganisms in 57.4%, gram-negative microorganisms in 14.8%, fungi in 20%, while in 18.9% of cases, IE was culture-negative. Aortic valve was the most commonly infected valve followed by mitral, tricuspid and the pulmonary valve. Diagnosis was set with a transthoracic ultrasound in half the cases, followed by transesophageal ultrasound and autopsy. Fever was present in most cases, while embolic phenomena were noted in two out of five cases. Aminoglycosides, cephalosporins and aminopenicillins were the most commonly used antimicrobials, and surgical management was performed in one out of three cases. Clinical cure was noted in 60.9%, while overall mortality was 45.3%. To conclude, this systematic review thoroughly describes IE in kidney transplant recipients and provides information on epidemiology, clinical presentation, treatment and outcomes. Moreover, it identifies the emerging role of Enterococci, gram-negatives and fungi in IE in this population.

Matched retrospective study of infective endocarditis among solid organ transplant recipients compared to non-transplant: Seven-year experience in a US Referral Center

BACKGROUND

Infective endocarditis (IE) is a rare complication following solid organ transplant (SOT); data on the clinical features and outcomes of IE in SOT recipients in the modern era are limited.

METHODS

We conducted a single-center retrospective cohort study of IE diagnosed from 1/2008-12/2014 in SOT recipients, who were matched by age and microorganism to cases of IE in non-SOT, to describe the clinical features and outcomes.

RESULTS

There were 14 cases of IE identified in SOT recipients matched to 56 non-SOT controls. Median time from transplant to IE was 1017 days (IQR 379-1830). Compared to non-SOT patients, SOT patients were more likely to be undergoing current hemodialysis (16% vs 36%) and to possess indwelling central venous catheters within the 30 days prior to diagnosis of IE (27% vs 50%). No SOT patients had documented drug use as a risk factor for IE whereas 6 (11%) non-SOT did. Enterococcus was the most common etiologic agent and was isolated in 50% of cases; only one fungal infection was identified, a mixed infection with Candida. Thirty-day mortality was 14% in SOT patients, significantly higher versus no deaths in non-SOT (P = .037).

CONCLUSIONS

The present study illustrates a change in epidemiology of IE in SOT patients characterized by IE that generally occurs more than one-year post-transplant, is due to bacterial infection rather than fungus, and appears to be health care associated. Multicenter studies are merited to explore transplant-specific risk factors for IE in the special population of SOT patients.