Outcomes of Reoperative Valve Replacement in Patients with Prosthetic Valve Endocarditis: A 20-Year Experience

Four decades of experience of prosthetic valve endocarditis reflect a high variety of diverse pathogens

Prosthetic valve endocarditis (PVE) remains a serious condition with a high mortality rate. Precise identification of the PVE-associated pathogen/s and their virulence is essential for successful therapy, and patient survival. The commonly described PVE-associated pathogens are staphylococci, streptococci and enterococci, with Staphylococcus aureus being the most frequently diagnosed species. Furthermore, multi-drug resistance pathogens are increasing in prevalence, and continue to pose new challenges mandating a personalized approach. Blood cultures in combination with echocardiography are the most common methods to diagnose PVE, often being the only indication, it exists. In many cases, the diagnostic strategy recommended in the clinical guidelines does not identify the precise microbial agent and to frequently, false negative blood cultures are reported. Despite the fact that blood culture findings are not always a good indicator of the actual PVE agent in the valve tissue, only a minority of re-operated prostheses are subjected to microbiological diagnostic evaluation. In this review, we focus on the diversity and the complete spectrum of PVE-associated bacterial, fungal and viral pathogens in blood, and prosthetic heart valve, their possible virulence potential, and their challenges in making a microbial diagnosis. We are curious to understand if the unacceptable high mortality of PVE is associated with the high number of negative microbial findings in connection with a possible PVE. Herein, we discuss the possibilities and limits of the diagnostic methods conventionally used and make recommendations for enhanced pathogen identification. We also show possible virulence factors of the most common PVE-associated pathogens and their clinical effects. Based on blood culture, molecular biological diagnostics, and specific valve examination, better derivations for the antibiotic therapy as well as possible preventive intervention can be established in the future.

Epidemiological investigation and physician awareness regarding the diagnosis and management of Q fever in South Korea, 2011 to 2017

BACKGROUND

In South Korea, the number of Q fever cases has rapidly increased since 2015. Therefore, this study aimed to characterize the epidemiological and clinical features of Q fever in South Korea between 2011 and 2017.

METHODS/PRINCIPAL FINDINGS

We analyzed the epidemiological investigations and reviewed the medical records from all hospitals that had reported at least one case of Q fever from 2011 to 2017. We also conducted an online survey to investigate physicians' awareness regarding how to appropriately diagnose and manage Q fever. The nationwide incidence rate of Q fever was annually 0.07 cases per 100,000 persons. However, there has been a sharp increase in its incidence, reaching up to 0.19 cases per 100,000 persons in 2017. Q fever sporadically occurred across the country, with the highest incidences in Chungbuk (0.53 cases per 100,000 persons per year) and Chungnam (0.27 cases per 100,000 persons per year) areas. Patients with acute Q fever primarily presented with mild illnesses such as hepatitis (64.5%) and isolated febrile illness (24.0%), whereas those with chronic Q fever were likely to undergo surgery (41.2%) and had a high mortality rate (23.5%). Follow-up for 6 months after acute Q fever was performed by 24.0% of the physician respondents, and only 22.3% of them reported that clinical and serological evaluations were required after acute Q fever diagnosis.

CONCLUSIONS

Q fever is becoming an endemic disease in the midwestern area of South Korea. Given the clinical severity and mortality of chronic Q fever, physicians should be made aware of appropriate diagnosis and management strategies for Q fever.

Contemporary Trends and Outcomes of Prosthetic Valve Infective Endocarditis in the United States: Insights from the Nationwide Inpatient Sample

BACKGROUND

Prosthetic valve endocarditis (PVE) carries high mortality and morbidity as compared to native valve endocarditis (NVE). Contemporary data on PVE are lacking, we aimed to study contemporary trends, outcomes, and burden of PVE using nationally representative data.

METHODS

We used the National Inpatient Sample from 2000 to 2017 to identify patients admitted with PVE using ICD-9-CM and ICD-10 codes. Risk-adjusted rates were calculated using an Analysis of Covariance (ANCOVA) with the Generalized Linear Model (GLM). Trends were assessed with linear regression and Pearson's Chi-square when appropriate. Binomial logistic regression was used to assess predictors of in-hospital mortality.

RESULTS

We identified 43,602 hospitalizations for PVE. PVE hospitalizations increased from 1803 in 2000 to 3450 in 2017. Risk-adjusted mortality decreased from 10.7% in 2002 to 7.3% in 2017 (P<0.01). Logistic regression analysis on mortality showed increase association with age (OR, 1.021, 95%CI [1.017-1.024], p<0.01), Hispanics (OR, 1.493, 95%CI [1.296-1.719], p<0.01) and patients with drug abuse(OR, 1.233, 95%CI [1.05-1.449], p=0.01). Co-morbid conditions like congestive heart failure (OR, 1.511, 95%CI [1.366-1.673], p<0.01), renal failure (OR, 1.572, 95%CI [1.427-1.732], p<0.01) and weight loss (OR, 1.425, 95%CI [1.093-1.419], p<0.01) were also associated with higher mortality.

CONCLUSIONS

Over the years the adjusted in-hospital mortality in PVE has trended down but the average cost of stay has increased despite decrease in length of stay.

Ethical Dilemma: Should Continuous Intravenous Drug Use Affect Appropriate Management in Prosthetic Valve Endocarditis?

Drug use is a major challenge that negatively impacts many aspects of health. The issue of drug use is growing with every passing day. Efforts to mitigate its use are countered by even more people succumbing to the intravenous drug use due to their relatively easy availability and patients' poor insight into their medical condition. Infective endocarditis (IE) is a condition with high mortality and morbidity. It requires prolonged treatment with antibiotics, and, under some special circumstances, surgical management is also necessitated. Intravenous drug users who get valve replacement after index IE episode may continue to use drugs despite our utmost efforts to prevent it. They can subsequently develop prosthetic valve endocarditis (PVE), which is one of the indications for surgical valve replacement, hence requiring a redo surgery. However, their irregular behavior can create reservations while considering a repeat valvular surgery and delay the appropriate treatment. This can increase morbidity and mortality from PVE in intravenous drug users with otherwise no or few comorbidities.

Higher incidence of perivalvular abscess determines perioperative clinical outcome in patients undergoing surgery for prosthetic valve endocarditis

Background

Cardiac surgery for prosthetic valve endocarditis (PVE) is associated with substantial mortality. We aimed to analyze 30-day and 1-year outcome in patients undergoing surgery for PVE and sought to identify preoperative risk factors for mortality with special regard to perivalvular infection.

Methods

We retrospectively analyzed data of 418 patients undergoing valve surgery for infective endocarditis between January 2009 and July 2018. After 1:1 propensity matching 158 patients (79 PVE/79 NVE) were analyzed with regard to postoperative 30-day and 1-year outcomes. Univariate and multivariable analyses were performed to identify potential risk factors for mortality.

Results

315 patients (75.4%) underwent surgery for NVE and 103 (24.6%) for PVE. After propensity matching groups were comparable with regard to preoperative characteristics, clinical presentation and microbiological findings, except a higher incidence of perivalvular infection in patients with PVE (51.9%) compared to NVE (26.6%) (p = 0.001), longer cardiopulmonary bypass (166 [76–130] vs. 97 [71–125] min; p < 0.001) and crossclamp time (95 [71–125] vs. 68 [55–85] min; p < 0.001). Matched patients with PVE showed a 4-fold increased 30-day mortality (20.3%) in comparison with NVE patients (5.1%) (p = 0.004) and 2-fold increased 1-year mortality (PVE 29.1% vs. NVE 13.9%; p = 0.020). Multivariable analysis revealed perivalvular abscess, sepsis, preoperative AKI and PVE as independent risk factors for mortality. Patients with perivalvular abscess had a significantly higher 30-day mortality (17.7%) compared to patients without perivalvular abscess (8.0%) (p = 0.003) and a higher rate of perioperative complications (need for postoperative pacemaker implantation, postoperative cerebrovascular events, postoperative AKI). However, perivalvular abscess did not influence 1-year mortality (20.9% vs. 22.3%; p = 0.806), or long-term complications such as readmission rate or relapse of IE.

Conclusions

Patients undergoing surgery for PVE had a significantly higher 30-day and 1-year mortality compared to NVE. After propensity-matching 30-day mortality was still 4-fold increased in PVE compared to NVE.

Patients with perivalvular abscess showed a significantly higher 30-day mortality and perioperative complications, whereas perivalvular abscess seems to have no relevant impact on 1-year mortality, the rate of readmission or relapse of IE.

Surgical results for prosthetic versus native valve endocarditis: A multicenter analysis

OBJECTIVES

Prosthetic valve endocarditis is associated with worse outcomes compared with native valve endocarditis. Our aim was to evaluate the impact of native valve endocarditis versus prosthetic valve endocarditis on postoperative outcomes and long-term survival and to identify preoperative risk factors in a large cohort of 4300 patients with infective endocarditis.

METHODS

This retrospective cohort study was conducted in 5 German Cardiac Surgery Centers: the Clinical Multicenter Project of Analysis of Infective Endocarditis in Germany. Data of 4300 patients undergoing valve surgery for native valve endocarditis and prosthetic valve endocarditis were retrospectively analyzed. Univariable and multivariable analyses were used for risk stratification, Kaplan-Meier analysis for long-term survival. In addition, we performed Cox proportional hazards regression with multivariable adjustment.

RESULTS

Between 1994 and 2016, 3143 patients (73.1%) underwent surgery for native valve endocarditis and 1157 patients (26.9%) underwent surgery for prosthetic valve endocarditis. Patients with prosthetic valve endocarditis were older (69 [60-75] vs 63 [52-72] years; P < .001) and had more comorbidities, such as hypertension (55% vs 46%; P < .001), diabetes (28% vs 25%; P = .020), coronary artery disease (32% vs 23%; P < .001), and preoperative acute kidney injury (41% vs 32%; P < .001). Kaplan-Meier analysis revealed significantly decreased long-term survival of patients undergoing surgery for prosthetic valve endocarditis compared with native valve endocarditis (P < .001). However, after multivariable adjustment, there was no significant difference in long-term survival between patients undergoing cardiac surgery with prosthetic valve endocarditis compared with native valve endocarditis.

CONCLUSIONS

After adjusting for preoperative comorbidities, long-term survival for prosthetic valve endocarditis and native valve endocarditis is comparable. Thus, our large cohort study provides evidence that prosthetic valve endocarditis alone should not be a contraindication for redo operations.