Infective Endocarditis Involving Implanted Cardiac Electronic Devices: JACC Focus Seminar 1/4.

Cardiac implantable electronic device-related infective endocarditis (CIED-IE) encompasses a range of clinical syndromes, including valvular, device lead, and bloodstream infections. However, accurately diagnosing CIED-IE remains challenging owing in part to diverse clinical presentations, lack of standardized definition, and variations in guideline recommendations. Furthermore, current diagnostic modalities, such as transesophageal echocardiography and [18F]-fluorodeoxyglucose positron emission tomography-computed tomography have limited sensitivity and specificity, further contributing to diagnostic uncertainty. This can potentially result in complications and unnecessary costs associated with inappropriate device extraction. Six hypothetical clinical cases that exemplify the diverse manifestations of CIED-IE are addressed herein. Through these cases, we highlight the importance of optimizing diagnostic accuracy and stewardship, understanding different pathogen-specific risks for bloodstream infections, guiding appropriate device extraction, and preventing CIED-IE, all while addressing key knowledge gaps. This review both informs clinicians and underscores crucial areas for future investigation, thereby shedding light on this complex and challenging syndrome.

Update on Cardiovascular Implantable Electronic Device Infections and Their Prevention, Diagnosis, and Management: A Scientific Statement From the American Heart Association: Endorsed by the International Society for Cardiovascular Infectious Diseases.

The American Heart Association sponsored the first iteration of a scientific statement that addressed all aspects of cardiovascular implantable electronic device infection in 2010. Major advances in the prevention, diagnosis, and management of these infections have occurred since then, necessitating a scientific statement update. An 11-member writing group was identified and included recognized experts in cardiology and infectious diseases, with a career focus on cardiovascular infections. The group initially met in October 2022 to develop a scientific statement that was drafted with front-line clinicians in mind and focused on providing updated clinical information to enhance outcomes of patients with cardiovascular implantable electronic device infection. The current scientific statement highlights recent advances in prevention, diagnosis, and management, and how they may be incorporated in the complex care of patients with cardiovascular implantable electronic device infection.

Nondental Invasive Procedures and Risk of Infective Endocarditis: Time for a Revisit: A Science Advisory From the American Heart Association.

There have been no published prospective randomized clinical trials that have: (1) established an association between invasive dental and nondental invasive procedures and risk of infective endocarditis; or (2) defined the efficacy and safety of antibiotic prophylaxis administered in the setting of invasive procedures in the prevention of infective endocarditis in high-risk patients. Moreover, previous observational studies that examined the association of nondental invasive procedures with the risk of infective endocarditis have been limited by inadequate sample size. They have typically focused on a few potential at-risk surgical and nonsurgical invasive procedures. However, recent investigations from Sweden and England that used nationwide databases and demonstrated an association between nondental invasive procedures, and the subsequent development of infective endocarditis (in particular, in high-risk patients with infective endocarditis) prompted the development of the current science advisory.

Routine Donor and Recipient Screening for Mycoplasma hominis and Ureaplasma Species in Lung Transplant Recipients.

Background: Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum may cause post-transplant infections in lung transplant recipients. We evaluated routine pretransplant screening for these Mollicutes. Methods: We retrospectively reviewed records of lung transplant recipients at our tri-site institution from 01/01/2015 to 11/15/2019. M. hominis and/or Ureaplasma polymerase chain reaction (PCR) was performed on pretransplant recipient urine specimens and donor bronchial swabs at the time of transplantation. Development of Mollicute infection and hyperammonemia syndrome (HS) was recorded. Results: A total of 268 patients underwent lung transplantation during the study period, of whom 105 were screened with at least 1 Mollicute PCR. Twelve (11%) screened positive; 10 donors, 1 recipient, and 1 both. Among positive donors, 3 were positive for M. hominis, 5 for U. urealyticum, and 4 for U. parvum. Preemptive therapy included doxycycline, levofloxacin, and/or azithromycin administered for 1-12 weeks. Despite therapy, 1 case of M. hominis mediastinitis and 1 case of HS associated with Ureaplasma infection occurred, both donor-derived. Of those screened before transplant, cases with positive screening were more likely (P < 0.05) to develop Mollicute infection despite treatment (2/12, 17%) than those who screened negative (1/93, 1%). Conclusions: Pretransplant recipient urine screening had a low yield and was not correlated with post-transplant Mollicute infection, likely because most M. hominis and U. parvum/urealyticum infections in lung transplant recipients are donor-derived. Routine donor bronchus swab PCR for M. hominis, U. urealyticum, and U. parvum followed by preemptive therapy did not obviously impact the overall incidence of Mollicute infection or HS in this cohort.

Management of Infective Endocarditis in People Who Inject Drugs: A Scientific Statement From the American Heart Association.

BACKGROUND: The American Heart Association has sponsored both guidelines and scientific statements that address the diagnosis, management, and prevention of infective endocarditis. As a result of the unprecedented and increasing incidence of infective endocarditis cases among people who inject drugs, the American Heart Association sponsored this original scientific statement. It provides a more in-depth focus on the management of infective endocarditis among this unique population than what has been provided in prior American Heart Association infective endocarditis-related documents. METHODS: A writing group was named and consisted of recognized experts in the fields of infectious diseases, cardiology, addiction medicine, and cardiovascular surgery in October 2021. A literature search was conducted in Embase on November 19, 2021, and multiple terms were used, with 1345 English-language articles identified after removal of duplicates. CONCLUSIONS: Management of infective endocarditis in people who inject drugs is complex and requires a unique approach in all aspects of care. Clinicians must appreciate that it requires involvement of a variety of specialists and that consultation by addiction-trained clinicians is as important as that of more traditional members of the endocarditis team to improve infective endocarditis outcomes. Preventive measures are critical in people who inject drugs and are cured of an initial bout of infective endocarditis because they remain at extremely high risk for subsequent bouts of infective endocarditis, regardless of whether injection drug use is continued.

Metagenomic shotgun sequencing of blood to identify bacteria and viruses in leukemic febrile neutropenia.

Despite diagnostic advances in microbiology, the etiology of neutropenic fever remains elusive in most cases. In this study, we evaluated the utility of a metagenomic shotgun sequencing based assay for detection of bacteria and viruses in blood samples of patients with febrile neutropenia. We prospectively enrolled 20 acute leukemia patients and obtained blood from these patients at three time points: 1) anytime from onset of neutropenia until before development of neutropenic fever, 2) within 24 hours of onset of neutropenic fever, 3) 5-7 days after onset of neutropenic fever. Blood samples underwent sample preparation, sequencing and analysis using the iDTECT® Dx Blood v1® platform (PathoQuest, Paris, France). Clinically relevant viruses or bacteria were detected in three cases each by metagenomic shotgun sequencing and blood cultures, albeit with no concordance between the two. Further optimization of sample preparation methods and sequencing platforms is needed before widespread adoption of this technology into clinical practice.

COVID-19 Pathogenesis and Clinical Manifestations.

In this review, we summarize the current knowledge about the virology, the host-pathogen interactions and pathogenesis of coronavirus disease 2019 in humans. We also describe the various clinical presentations of the disease including respiratory system and extrapulmonary manifestations.

Increased rates of blood culture contamination during the coronavirus disease 2019 pandemic.

We observed a higher rate of blood-culture contamination during the COVID-19 pandemic at our institution compared to a prepandemic period. Given the potential implications of blood contamination in antibiotic and diagnostic test utilization as well as added cost, it is imperative to continue efforts to minimize these episodes during the pandemic.

Transient Hepatitis B Surface Antigenemia Following Immunization with Heplisav-B.

OBJECTIVE: To delineate the rate and duration of transient hepatitis B surface antigenemia following Heplisav-B vaccination. PATIENTS AND METHODS: We retrospectively reviewed the medical records of all adult patients who received Heplisav-B vaccination at our institution from January 1, 2019, through March 31, 2020, and who had hepatitis B surface antigen (HBsAg) testing within 30 days following immunization. Patients with laboratory evidence of prior hepatitis B virus infection or immunization were excluded. RESULTS: A total of 39 of 1933 patients were tested for HBsAg within 30 days after completing the Heplisav-B vaccination series; of these 39, only 6 (15.4 %) had a positive HBsAg result. Compared with the patients with negative HBsAg results, those with a positive HBsAg result had a significantly lower body mass index (24.8 kg/m2 [interquartile range (IQR), 23 to 26.4 kg/m2] vs 28.6 kg/m2 [IQR, 26.4 to 30.6 kg/m2]; P=.01) and higher prevalence of chronic kidney disease (2 of 6 [33.3%] vs 2 of 33 [6%]; P=.04). The timing of HBsAg testing after completing the vaccination series in the HBsAg-positive group was significantly earlier compared with that of the HBsAg-negative group (2 days [IQR, 0.43 to 2.25 days) vs 12 days [IQR, 10 to 15 days]; P=.0008). Active hepatitis B infection was excluded in all 6 patients. In the HBsAg-positive group, the median time from the date of Heplisav-B administration to a negative HBsAg test result was 17 days (IQR, 8 to 36 days). CONCLUSION: As with all conventional hepatitis B vaccines, transient hepatitis B surface antigenemia can be observed with Heplisav-B vaccine, particularly in those with chronic kidney disease and low body mass index.

Bacterial Brain Abscess: An Outline for Diagnosis and Management.

Despite advances in the diagnosis and management of brain abscess, significant associated morbidity and mortality remain high. We retrospectively reviewed adults who presented with pyogenic brain abscess from January 1, 2009, through June 30, 2020. Overall, 247 patients were identified. The median age was 59 years, and 33.6% had a history of head and neck surgery or traumatic brain injury. Diagnostic brain magnetic resonance imaging (MRI) was performed in the bulk (93.1%) of patients. A total of 205 patients (83%) were managed with medical and surgical treatment. The most common definitive antibiotic regimen was monotherapy (48.2%). The median duration of antimicrobial therapy was 42 days. Compared with those who received combined therapy, patients with medical therapy alone had a higher mortality rate (21.4% vs 6%; P =. 003) with more neurologic sequelae (31% vs 27.1%; P = .5). Most patients with brain abscesses are older with multiple underlying comorbidities, and one-third had antecedent head and neck surgery. A prompt combined surgical and medical approach with prolonged antimicrobial therapy may cure the infection with avoidance of permanent residual neurologic deficits.

Detection of Pathogenic Bacteria From Septic Patients Using 16S Ribosomal RNA Gene-Targeted Metagenomic Sequencing.

BACKGROUND: Conventional blood cultures were compared to plasma cell-free DNA-based 16S ribosomal RNA (rRNA) gene polymerase chain reaction (PCR)/next-generation sequencing (NGS) for detection and identification of potential pathogens in patients with sepsis. METHODS: Plasma was prospectively collected from 60 adult patients with sepsis presenting to the Mayo Clinic (Minnesota) Emergency Department from March through August 2019. Results of routine clinical blood cultures were compared to those of 16S rRNA gene NGS. RESULTS: Nineteen (32%) subjects had positive blood cultures, of which 13 yielded gram-negative bacilli, 5 gram-positive cocci, and 1 both gram-negative bacilli and gram-positive cocci. 16S rRNA gene NGS findings were concordant in 11. For the remaining 8, 16S rRNA gene NGS results yielded discordant detections (n = 5) or were negative (n = 3). Interestingly, Clostridium species were additionally detected by 16S rRNA gene NGS in 3 of the 6 subjects with gastrointestinal sources of gram-negative bacteremia and none of the 3 subjects with urinary sources of gram-negative bacteremia. In the 41 remaining subjects, 16S rRNA gene NGS detected at least 1 potentially pathogenic organism in 17. In 15, the detected microorganism clinically correlated with the patient's syndrome. In 17 subjects with a clinically defined infectious syndrome, neither test was positive; in the remaining 7 subjects, a noninfectious cause of clinical presentation was identified. CONCLUSIONS: 16S rRNA gene NGS may be useful for detecting bacteria in plasma of septic patients. In some cases of gram-negative sepsis, it may be possible to pinpoint a gastrointestinal or urinary source of sepsis based on the profile of bacteria detected in plasma.

Antibiotic-Eluting Envelopes to Prevent Cardiac-Implantable Electronic Device Infection: Past, Present, and Future.

OBJECTIVE: Cardiac-implantable electronic device (CIED) infections are associated with significant morbidity and mortality. In this review, we describe the risk factors and pathogenesis of CIED infections and review the rationale and the evidence for the use of antibiotic-eluting envelopes (ABEs) in patients at increased risk for CIED infections. FINDINGS: The majority of CIED infections are caused by staphylococci that involve generator pocket and occur due to contamination of the device or the pocket tissues at the time of implantation. Clinical trials have shown that extending the duration of post-operative systemic antibacterial therapy is not beneficial in reducing CIED infection rate. However, ABEs that reduce device migration after implantation and provide sustained local delivery of prophylactic antibiotics at the pocket site, may provide benefit in reducing infection. Currently, there are two types of commercially available CIED envelope devices in the United States. The first ABE device (TYRX™, Medtronic Inc., Monmouth Junction, NJ) is composed of a synthetic absorbable mesh envelope that elutes minocycline and rifampin and has been shown to reduce CIED pocket infections in a large multi-center randomized clinical trial. The second ABE device (CanGaroo-G™, Aziyo Biologics, Silver Spring, MD) is composed of decellularized extracellular matrix (ECM) and was originally designed to stabilize the device within the pocket, limiting risk for migration or erosion, and providing a substrate for tissue ingrowth in a preclinical study. This device has shown promising results in a preclinical study with local delivery of gentamicin. Compared with artificial materials, such as synthetic surgical mesh, biologic ECM has been shown to foster greater tissue integration and vascular ingrowth, a reduced inflammatory response, and more rapid clearance of bacteria. CONCLUSIONS AND RELEVANCE: ABE devices provide sustained local delivery of antibiotics at the generator pocket site and appear beneficial in reducing CIED pocket infections. Given the continued increase in the use of CIED therapy and resultant infectious complications, innovative approaches to infection prevention are critical.

Lawsonella clevelandensis: an emerging cause of vascular graft infection.

Lawsonella clevelandensis, an emerging pathogen, was first described in 2016, and has been implicated in abdominal, breast and spinal abscesses in a limited number of cases. Being a fastidious organism, it is primarily identified with molecular methods. With the incorporation of broad-range PCR testing in clinical diagnostics, L. clevelandensis has been increasingly reported in the literature. We describe a case of a 65-year-old man who presented with bilateral psoas abscesses secondary to aorto-bi-iliac vascular graft infection with L. clevelandensis identified using 16S rRNA/PCR sequencing. The patient underwent surgical resection and replacement of infected graft, followed by 6 weeks of intravenous antibiotic therapy and then chronic suppression with doxycycline and cefadroxil. He was infection-free at last follow-up.

D-index as a marker of bloodstream infections in patients with allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Neutropenia is a risk factor for development of infections; however, the direct effect of neutropenia on development of bloodstream infection (BSI) is not known. D-index, which is area between the neutrophil time curve and a neutrophil count of 0.5 × 109 /L, incorporates the combined effect of severity and duration of neutropenia. We aimed to evaluate whether D-index can be used as a marker for BSI in patients with allogeneic stem cell transplantation. METHOD: We conducted a retrospective cohort study of patients undergoing allogeneic stem cell transplantation between January 1, 2005, and September 30, 2015. The primary outcome measure was the development of BSI within 30 days of transplantation. RESULTS: A total of 714 patients were included in the study of whom 101 developed BSI. Patients with BSI had a significantly higher median D-index value compared with patients who did not have BSI (4990 vs. 3570, P < .001). As a marker, the performance of the D-index was similar to that of the duration of profound neutropenia (P = .18) and significantly better than the total duration of neutropenia (P = .001). CONCLUSION: The D-index performed better than the total duration of neutropenia as a marker for BSI in patients with allogeneic stem cell transplantation. There was no difference between D-index and, a more easily calculable indicator, duration of profound neutropenia.

Management of Bloodstream Infections in Left Ventricular Assist Device Recipients: To Suppress, or Not to Suppress?

BACKGROUND: Ascertaining involvement of left ventricular assist device (LVAD) in a patient presenting with bloodstream infection (BSI) can be challenging, frequently leading to use of chronic antimicrobial suppressive (CAS) therapy. We aimed to assess the efficacy of CAS therapy to prevent relapse of BSI from LVAD and non-LVAD sources. METHODS: We retrospectively screened adults receiving LVAD support from 2010 through 2018, to identify cases of BSI. Bloodstream infection events were classified into LVAD-related, LVAD-associated, and non-LVAD BSIs. RESULTS: A total of 121 episodes of BSI were identified in 80 patients. Of these, 35 cases in the LVAD-related, 14 in the LVAD-associated, and 46 in the non-LVAD BSI groups completed the recommended initial course of therapy and were evaluated for CAS therapy. Chronic antimicrobial suppressive therapy was prescribed in most of the LVAD-related BSI cases (32 of 35, 91.4%) and 12 (37.5%) experienced relapse. Chronic antimicrobial suppressive therapy was not prescribed in a majority of non-LVAD BSI cases (33, 58.9%), and most (31, 93.9%) did not experience relapse. Chronic antimicrobial suppressive therapy was prescribed in 9 of 14 (64.2%) cases of LVAD-associated BSI and none experienced relapse. Of the 5 cases in this group that were managed without CAS, 2 had relapse. CONCLUSIONS: Patients presenting with LVAD-related BSI are at high risk of relapse. Consequently, CAS therapy may be a reasonable approach in the management of these cases. In contrast, routine use of CAS therapy may be unnecessary for non-LVAD BSIs.

Discriminative Ability and Reliability of Transesophageal Echocardiography in Characterizing Cases of Cardiac Device Lead Vegetations Versus Noninfectious Echodensities.

BACKGROUND: Approximately one-third of cases of cardiovascular implantable electronic device (CIED) infection present as CIED lead infection. The precise transesophageal echocardiographic (TEE) definition and characterization of "vegetation" associated with CIED lead infection remain unclear. METHODS: We identified a sample of 25 consecutive cases of CIED lead infection managed at our institution between January 2010 and December 2017. Cases of CIED lead infection were classified using standardized definitions. Similarly, a sample of 25 noninfected patients who underwent TEE that showed a defined lead echodensity during the study period was included as a control group. TEEs were reviewed by 2 independent echocardiologists who were blinded to all linked patient demographic, clinical, and microbiological information. Reported echocardiographic variables of the infected vs noninfected cases were compared, and the overall diagnostic performance was analyzed. RESULTS: Descriptions of lead echodensities were variable and there were no significant differences in median echodensity diameter or mobility between infected vs noninfected groups. Among infected cases, blinded echocardiogram reports by either reviewer correctly made a prediction of infection in 6 of 25 (24%). Interechocardiologist agreement was 68%. Sensitivity of blinded TEEs ranged from 31.5% to 37.5%. CONCLUSIONS: Infectious vs noninfectious lead echodensities could not be reliably distinguished on the basis of size, mobility, and general shape descriptors obtained from a retrospective blinded TEE examination without knowledge of clinical and microbiological parameters. Therefore, a reanalysis of criteria used to support a diagnosis of CIED lead infection may be warranted.

Invasive Pulmonary Aspergillosis in Patients with SARS-CoV-2 Infection: A Systematic Review of the Literature.

In this systematic review, we investigate the epidemiology, pathogenesis, risk factors, clinical manifestations, diagnosis and treatment of COVID-19-associated pulmonary aspergillosis (CAPA). We identified 85 cases from 22 studies. The frequency of CAPA is currently unknown but ranges between <5% to >30% in different case series; the possibility of colonization rather than invasive disease is the most important confounder. The vast majority of patients with CAPA did not have any of the classic host risk factors, such as immunosuppression from organ transplant or neutropenia, although a significant proportion (46%) had received corticosteroids. Age, pulmonary comorbidities and male sex were associated with higher mortality. Patients treated with voriconazole had numerically lower case-fatality rate. Clinical vigilance for CAPA is advisable in critically ill patients with COVID-19 who are not improving, even those who do not meet classic host criteria for invasive mycoses, especially if they are receiving corticosteroids. A thorough, multi-faceted diagnostic work-up and early initiation of a mold-active triazole may be lifesaving. Further research studies using standardized, uniform definitions of invasive disease and colonization are urgently needed.

Management and Outcome of Left Ventricular Assist Device Infections in Patients Undergoing Cardiac Transplantation.

BACKGROUND: Postoperative management of patients undergoing cardiac transplantation with an infected left ventricular assist device (LVAD) is unclear. METHODS: We retrospectively screened all adults with an LVAD who underwent cardiac transplantation at our institution from 2010 through 2018. We selected all cases of LVAD-specific and LVAD-related infections who were receiving antimicrobial therapy as initial treatment course or chronic suppression at the time of cardiac transplantation. Non-LVAD infections, superficial driveline-infection, or concurrent use of right ventricular assist device or extracorporeal membrane oxygenation device were excluded. RESULTS: A total of 54 cases met study criteria with 18 of 54 (33.6%) classified as LVAD- specific or related infections and 36 of 54 (66.6%) as noninfected. cases of lvad infection had a higher median charlson comorbidity Index score at the time of transplantation compared with noninfected cases (P = .005). Of the 18 cases of infection, 13 of 18 (72.2%) were classified as LVAD-specific and 5 of 18 (27.8%) were classified as LVAD-related. Nine of 13 (69.2%) cases had proven LVAD-specific infections. Antimicrobial therapy was extended posttransplant to treat preceding LVAD-specific infection in all 9 cases (9 of 13, 69.2%) with a median duration of 14 days (interquartile range, 14-28). After LVAD removal, antimicrobial treatment was not continued for preceding LVAD-related infections. CONCLUSIONS: Patients with an LVAD-specific infection were treated with 2 weeks of pathogen-directed therapy postheart transplant without any relapses. For those without LVAD-specific infection or uncomplicated LVAD-related bacteremia who had completed antimicrobial therapy pretransplant, antibiotics were discontinued after standard perioperative prophylaxis and no relapses were observed.

Treatment Considerations for COVID-19: A Critical Review of the Evidence (or Lack Thereof).

The novel severe acute respiratory syndrome coronavirus 2 is causing a worldwide pandemic that may lead to a highly morbid and potentially fatal coronavirus disease 2019 (COVID-19). There is currently no drug that has been proven as an effective therapy for COVID-19. Several candidate drugs are being considered and evaluated for treatment. This includes clinically available drugs, such as chloroquine, hydroxychloroquine, and lopinavir/ritonavir, which are being repurposed for the treatment of COVID-19. Novel experimental therapies, such as remdesivir and favipiravir, are also actively being investigated for antiviral efficacy. Clinically available and investigational immunomodulators, such as the interleukin 6 inhibitors tocilizumab and sarilumab and the anti-granulocyte-macrophage colony-stimulating factor lenzilumab, are being tested for their anticipated effect in counteracting the pro-inflammatory cytokine environment that characterizes severe and critical COVID-19. This review article examines the evidence behind the potential use of these leading drug candidates for the treatment of COVID-19. The authors conclude, based on this review, that there is still no high-quality evidence to support any of these proposed drug therapies. The authors, therefore, encourage the enrollment of eligible patients to multiple ongoing clinical trials that assess the efficacy and safety of these candidate therapies. Until the results of controlled trials are available, none of the suggested therapeutics is clinically proven as an effective therapy for COVID-19.