Executive Summary: State-of-the-Art Review: Fostering Collaborative Teamwork-A Comprehensive Approach to Vascular Graft Infection Following Arterial Reconstructive Surgery.

Vascular graft infection (VGI) is one of the most serious complications following arterial reconstructive surgery. VGI has received increasing attention over the past decade, but many questions remain regarding its diagnosis and management. In this review, we describe our approach to VGI through multidisciplinary collaboration and discuss decision-making for challenging presentations. This document will concentrate on VGI that impacts both aneurysms and pseudoaneurysms excluding the ascending thoracic aorta.

Fostering Collaborative Teamwork-A Comprehensive Approach to Vascular Graft Infection Following Arterial Reconstructive Surgery.

Vascular graft infection (VGI) is one of the most serious complications following arterial reconstructive surgery. VGI has received increasing attention over the past decade, but many questions remain regarding its diagnosis and management. In this review, we describe our approach to VGI through multidisciplinary collaboration and discuss decision making for challenging presentations. This review will concentrate on VGI that impacts both aneurysms and pseudoaneurysms excluding the ascending thoracic aorta.

Percutaneous mechanical aspiration in patients with right-sided infective endocarditis: An analysis of the national inpatient sample database-2016-2020.

BACKGROUND: Given the challenges of conventional therapies in managing right-sided infective endocarditis (RSIE), percutaneous mechanical aspiration (PMA) of vegetations has emerged as a novel treatment option. Data on trends, characteristics, and outcomes of PMA, however, have largely been limited to case reports and case series. AIMS: The aim of the current investigation was to provide a descriptive analysis of PMA in the United States and to profile the frequency of PMA with a temporal analysis and the patient cohort. METHODS: The International Classification of Diseases, 10th Revision codes were used to identify patients with RSIE in the national (nationwide) inpatient sample (NIS) database between 2016 and 2020. The clinical characteristics and temporal trends of RSIE hospitalizations in patients who underwent PMA was profiled. RESULTS: An estimated 117,955 RSIE-related hospital admissions in the United States over the 5-year study period were estimated and 1675 of them included PMA. Remarkably, the rate of PMA for RSIE increased 4.7-fold from 2016 (0.56%) to 2020 (2.62%). Patients identified with RSIE who had undergone PMA were young (medial age 36.5 years) and had few comorbid conditions (median Charlson Comorbidity Index, 0.6). Of note, 36.1% of patients had a history of hepatitis C infection, while only 9.9% of patients had a cardiovascular implantable electronic device. Staphylococcus aureus was the predominant (61.8%) pathogen. Concomitant transvenous lead extraction and cardiac valve surgery during the PMA hospitalization were performed in 18.2% and 8.4% of admissions, respectively. The median hospital stay was 19.0 days, with 6.0% in-hospital mortality. CONCLUSIONS: The marked increase in the number of PMA procedures in the United States suggests that this novel treatment option has been embraced as a useful tool in select cases of RSIE. More work is needed to better define indications for the procedure and its efficacy and safety.

Prevention of Viridans Group Streptococcal Infective Endocarditis: A Scientific Statement From the American Heart Association.

BACKGROUND: In 2007, the American Heart Association published updated evidence-based guidelines on the recommended use of antibiotic prophylaxis to prevent viridans group streptococcal (VGS) infective endocarditis (IE) in cardiac patients undergoing invasive procedures. The 2007 guidelines significantly scaled back the underlying conditions for which antibiotic prophylaxis was recommended, leaving only 4 categories thought to confer the highest risk of adverse outcome. The purpose of this update is to examine interval evidence of the acceptance and impact of the 2007 recommendations on VGS IE and, if needed, to make revisions based on this evidence. METHODS AND RESULTS: A writing group was formed consisting of experts in prevention and treatment of infective endocarditis including members of the American Dental Association, the Infectious Diseases Society of America, and the American Academy of Pediatrics, in addition to the American Heart Association. MEDLINE database searches were done for English language articles on compliance with the recommendations in the 2007 guidelines and the frequency of and morbidity or mortality from VGS IE after publication of the 2007 guidelines. Overall, there was good general awareness of the 2007 guidelines but variable compliance with recommendations. There was no convincing evidence that VGS IE frequency, morbidity, or mortality has increased since 2007. CONCLUSIONS: On the basis of a review of the available evidence, there are no recommended changes to the 2007 VGS IE prevention guidelines. We continue to recommend VGS IE prophylaxis only for categories of patients at highest risk for adverse outcome while emphasizing the critical role of good oral health and regular access to dental care for all. Randomized controlled studies to determine whether antibiotic prophylaxis is effective against VGS IE are needed to further refine recommendations.

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.

Repeat transesophageal echocardiography in infective endocarditis: An analysis of contemporary utilization.

BACKGROUND: Current guidelines from the American Heart Association (AHA) recommend repeating transesophageal echocardiography (TEE) in three to five days if there is high suspicion of IE despite an initial TEE that was negative. This recommendation, however, is based on limited published data. OBJECTIVES: This investigation attempts to identify specific factors that prompted repeat TEE and evaluate the yield of IE-related findings demonstrated by repeat TEE as compared to initial or prior TEE. METHODS: A retrospective cohort who had at least one repeat TEE during an index hospitalization or initial course of antimicrobial therapy for IE between January 2014 and September 2018. We assessed the impact of repeat TEE on IE diagnosis and patient management and included a comparative analysis of patients with initial TEE only. RESULTS: Overall, 59 (44.7%) of 132 IE patients underwent repeat TEE. In a comparative analysis that involved patients who had undergone an initial TEE only versus those who had repeat TEE, male gender (P = .029) and presence of a prosthetic valve or annuloplasty ring (P = .017) were significantly associated with repeat TEE. Importantly, 8 (17.4%) of repeat TEE were critical for IE diagnosis, 8 (17.4%) impacted antimicrobial management, and 11 (23.9%) supported cardiovascular surgical intervention. CONCLUSIONS: From a population-based cohort of incident IE cases, repeat TEE was more frequently (44.7%) done in patients with suspect or proven IE and associated complications than anticipated. Repeat TEE remains pivotal in a contemporary practice that involves critical aspects of IE diagnosis and management.

Diagnostic evaluation and management of culture-negative cardiovascular implantable electronic device infections.

BACKGROUND: Culture-negative (CN) cardiovascular implantable electronic device (CIED) infections represent a significant management challenge for clinicians with no specific guidelines addressing this subgroup of patients. The aim of the current investigation is to report our institutional experience of CN CIED infections and propose a systematic approach to diagnostic evaluation and management of these complicated cases based on our observations. METHODS: We retrospectively screened all CIED infection cases at Mayo Clinic from 2005 through 2017. Using standardized criteria to define significant microbial growth, all patients with positive blood or pocket/device cultures were excluded. RESULTS: A total of 835 cases of CIED infection were screened, and of these, 47 (6%) met CN-CIED infection criteria. Majority of patients (77%) in this cohort had received antimicrobial therapy prior to device cultures with a median duration of 8 days. The most common presentation was device pocket infection (81%). All patients underwent device removal. Route of antibiotics was switched from oral to parenteral and spectrum of activity expanded from initial therapy in 23% of patients despite negative cultures. Majority of patients (80%) were dismissed on parenteral therapy. Adverse events attributed to intravenous antibiotic therapy were documented in 63% of the cases. No recurrence was reported and 6-month survival was 94.8%. CONCLUSIONS: Pocket and device cultures in suspected CIED infections may be negative due to preextraction oral antibiotics. However, frequently these patients are managed with broad-spectrum parenteral therapy postextraction.

Outcomes in Patients With Cardiovascular Implantable Electronic Device Infection Managed With Chronic Antibiotic Suppression.

BACKGROUND.: Most cardiovascular implantable electronic device (CIED) recipients are elderly, have multiple comorbid conditions, and are at increased risk of CIED infection (CIEDI). Current guidelines recommend complete device removal in patients with CIEDI to prevent relapse and mortality. However, comorbidities or other factors may preclude device removal, thus prompting a nonsurgical approach that includes chronic antibiotic suppression (CAS). There are limited data on outcomes of patients receiving CAS for CIEDI. METHODS.: We retrospectively screened 660 CIEDI cases from 2005 to 2015 using electronic health records and a CIEDI institutional database and identified 48 patients prescribed CAS. Primary outcomes were infection relapse and survival. RESULTS.: The median age was 78 years, and 73% (35/48) were male. The median Charlson comorbidity index was 4. Common pathogens were coagulase-negative staphylococci (21%, 10/48) and methicillin-sensitive Staphylococcus aureus (19%, 9/48). At 1 month after hospitalization, 25% (12/48) of patients had died, of whom only 1 initiated CAS; 67% (8/12) of these had staphylococcal infections. Of the 37 patients who initiated CAS, the most common antimicrobials were trimethoprim-sulfamethoxazole, penicillin, and amoxicillin (22%, 8/37 each). Estimated median overall survival was 1.43 years (95% confidence interval, 0.27-2.14), with 18% (6/33 survivors) developing relapse within 1 year. Of the 6 patients who relapsed, 2 (33%) subsequently underwent CIED extraction. CONCLUSION.: CAS is reasonable in select patients who are not candidates for complete device removal for attempted cure of CIEDI. Nevertheless, 1-month mortality in our sample of CAS-eligible patients was high and reflective of high rates of comorbid conditions.

Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Scientific Statement for Healthcare Professionals From the American Heart Association.

BACKGROUND: Infective endocarditis is a potentially lethal disease that has undergone major changes in both host and pathogen. The epidemiology of infective endocarditis has become more complex with today's myriad healthcare-associated factors that predispose to infection. Moreover, changes in pathogen prevalence, in particular a more common staphylococcal origin, have affected outcomes, which have not improved despite medical and surgical advances. METHODS AND RESULTS: This statement updates the 2005 iteration, both of which were developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It includes an evidence-based system for diagnostic and treatment recommendations used by the American College of Cardiology and the American Heart Association for treatment recommendations. CONCLUSIONS: Infective endocarditis is a complex disease, and patients with this disease generally require management by a team of physicians and allied health providers with a variety of areas of expertise. The recommendations provided in this document are intended to assist in the management of this uncommon but potentially deadly infection. The clinical variability and complexity in infective endocarditis, however, dictate that these recommendations be used to support and not supplant decisions in individual patient management.

Cardiovascular Implantable Electronic Device Infections due to Propionibacterium Species.

INTRODUCTION: Propionibacterium species are part of the normal skin flora and often considered contaminants when identified in cultures. However, they can cause life-threatening infections, including prosthetic cardiovascular device infections. Clinical presentation and management of cardiovascular implantable electronic device (CIED) infection due to Propionibacterium species has not been well described. METHODS: Retrospective review of all cases of CIED infection due to Propionibacterium species admitted to Mayo Clinic between January 1, 1990 and December 31, 2014. Patient charts were reviewed for clinical, microbiological, and imaging data. Descriptive analysis was performed. RESULTS: We identified 14 patients with CIED infection due to Propionibacterium species, accounting for 2.3% of all CIED infections. Patients were predominantly male (n = 12, 86%). The median age at admission was 58.5 years (range 22-83). Twelve patients had implantable cardioverter defibrillators (ICDs) and two had permanent pacemaker systems. Twelve patients had generator pocket infection (86%). Two patients met clinical criteria for CIED-related infective endocarditis. Median time between last device manipulation and infection was 9 months (range 1-98). All patients were treated with complete device removal and antibiotic therapy. Six-month follow-up data were available for 10 patients (71%), with no relapses documented. CONCLUSION: CIED infections due to Propionibacterium species accounted for 2.3% of all device infections over a 25-year period. The most common infectious syndrome was generator pocket infection with delayed onset. There was an unanticipated predominance of ICDs in this cohort. Cure was achieved in all cases with complete device removal and antibiotic therapy.

Predicting Risk of Endocarditis Using a Clinical Tool (PREDICT): Scoring System to Guide Use of Echocardiography in the Management of Staphylococcus aureus Bacteremia.

BACKGROUND: Infective endocarditis (IE) is a serious complication of Staphylococcus aureus bacteremia (SAB). There is limited clinical evidence to guide use of echocardiography in the management of SAB cases. METHODS: Baseline and 12-week follow-up data of all adults hospitalized at our institution with SAB from 2006 to 2011 were reviewed. Clinical predictors of IE were identified using multivariable logistic regression analysis. RESULTS: Of the 757 patients screened, 678 individuals with SAB (24% community acquired, 56% healthcare associated, and 20% nosocomial) met study criteria. Eighty-five patients (13%) were diagnosed with definite IE within the 12 weeks of initial presentation based on modified Duke criteria. The proportion of patients with IE was 22% (36/166) in community-acquired SAB, 11% (40/378) in community-onset healthcare-associated SAB, and 7% (9/136) in nosocomial SAB. Community-acquired SAB, presence of cardiac device, and prolonged bacteremia (≥ 72 hours) were identified as independent predictors of IE in multivariable analysis. Two scoring systems, day 1 (SAB diagnosis day) and day 5 (when day 3 culture results are known), were derived based on the presence of these risk factors, weighted in magnitude by the corresponding regression coefficients. A score of ≥ 4 for day 1 model had a specificity of 96% and sensitivity of 21%, whereas a score of <2 for day 5 model had a sensitivity of 98.8% and negative predictive value of 98.5%. CONCLUSIONS: We propose 2 novel scoring systems to guide use of echocardiography in SAB cases. Larger prospective studies are needed to validate the classification performance of these scoring systems.

Association of Mitral Valve Prolapse With Infective Endocarditis Due to Viridans Group Streptococci.

Although patients with certain cardiac valve abnormalities have increased risk of infective endocarditis (IE), it is unknown whether these abnormalities are associated with specific pathogens in IE cases. We report a strong association between mitral valve prolapse and viridans group streptococcal IE in a population-based cohort from Olmsted County, Minnesota.

Temporal trends in infective endocarditis epidemiology from 2007 to 2013 in Olmsted County, MN.

BACKGROUND: The aim of this study is to determine if there have been contemporary shifts in infective endocarditis (IE) epidemiology in our local population; an analysis of cases from 2007 to 2013 was conducted. METHODS: This is a population-based review of all adults (≥18 years) residing in Olmsted County, MN, with definite or possible IE using the Rochester Epidemiology Project from January 1, 2007, to December 31, 2013. RESULTS: We identified 51 cases of IE in Olmsted County, MN, between 2007 and 2013. Median age of IE cases was 68.8 years (interquartile range 55.6-76.5), and 41% were females. Age- and sex-adjusted incidence of IE was 7.4 (95% CI 5.3-9.4) cases per 100,000 person-years. From a multivariable Poisson regression model, incidence of IE did not change significantly during the study period (P = .222) but was significantly higher in males and those of older age (P < .001). The annual incidences (per 100,000 person-years) were 2.5 for Staphylococcus aureus, 1.1 for viridans group streptococci, 1.6 for Enterococcus species, and 0.8 for coagulase-negative staphylococci. Only 19.6% (10/51) of Olmsted County patients underwent valve surgery between 2007 and 2013 as compared with 44.4% (197/444) of non-Olmsted County patients treated at Mayo Clinic Rochester. CONCLUSION: In this population-based study, no significant change in the overall incidence of IE in Olmsted County, MN, between 2007 and 2013 was seen, and it was similar to that seen between 1970 and 2006. Male gender and older age were associated with increased IE risk. With a lesser extent of cases attributable to viridans group streptococcal IE compared with previous years, S aureus was the predominant pathogen in IE cases during 2007 to 2013. The relatively low valve surgery rate was disparate from that reported from large, tertiary care centers (including our own) with non-population-based cohorts, which are subject to referral bias and can influence the expected characterization of IE.

Desulfovibrio legallii prosthetic shoulder joint infection and review of antimicrobial susceptibility and clinical characteristics of Desulfovibrio infections.

We describe a case of shoulder hemiarthroplasty infection with Desulfovibrio legallii. Antimicrobial susceptibilities of 36 Desulfovibrio isolates are presented. Metronidazole and carbapenems exhibited reliable activity, although piperacillin-tazobactam did not. Eleven previous cases of Desulfovibrio infection are reviewed; most arose from a gastrointestinal tract-related source.

Clinical presentation and outcomes of cardiovascular implantable electronic device infections in hemodialysis patients.

BACKGROUND: Infection is a serious complication of cardiovascular implantable electronic device (CIED) implantation. Kidney failure is as an independent risk factor for CIED infection and associated mortality. The presence of multiple comorbid conditions may contribute to varied clinical presentations and poor outcomes in hemodialysis (HD)-dependent patients with cardiac device infection. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: CIED infections in HD patients (n=17) and non-HD patients (n=398) at Mayo Clinic in Rochester, MN, between 1991 and 2008. OUTCOMES: Surgical management and death. MEASUREMENTS: Clinical presentations, microbial organisms. RESULTS: Of 415 patients admitted with CIED infection, 17 (4%) were receiving maintenance HD therapy. Among those on HD therapy, mean age was 72±15 (SD) years, 59% were women, and 53% had a central venous catheter for dialysis access. All 17 patients receiving HD therapy presented with CIED-associated bloodstream infection and 41% of these had infected vegetations on CIED leads or cardiac valves. A majority (82%) were managed with complete device removal and almost half (43%) received a replacement device when bloodstream infection cleared. Device infection was associated with significant short-term mortality in HD patients and 90-day survival was only 76% in this group of patients. LIMITATIONS: Smaller sample size, majority white cohort, observational study. CONCLUSIONS: CIED infection in patients receiving HD usually is associated with bloodstream infection and frequently is complicated with device-related endocarditis. Despite complete device removal in the majority of HD patients with infection, mortality remains high.

Incidence of infective endocarditis caused by viridans group streptococci before and after publication of the 2007 American Heart Association's endocarditis prevention guidelines.

BACKGROUND: The American Heart Association published updated guidelines for infective endocarditis (IE) prevention in 2007 that markedly restricted the use of antibiotic prophylaxis in certain at-risk patients undergoing dental and other invasive procedures. The incidence of IE caused by viridans group streptococci (VGS) in the United States after publication of the 2007 American Heart Association guidelines has not been reported. METHODS AND RESULTS: We performed a population-based review of all definite or possible cases of VGS-IE using the Rochester Epidemiology Project of Olmsted County, Minnesota. Patient demographics and microbiological data were collected for all VGS-IE cases diagnosed from January 1, 1999, through December 31, 2010. We also examined the Nationwide Inpatient Sample hospital discharge database to determine the number of VGS-IE cases included between 1999 and 2009. We identified 22 cases with VGS-IE in Olmsted County over the 12-year study period. Rates of incidence (per 100 000 person-years) during time intervals of 1999-2002, 2003-2006, and 2007-2010 were 3.19 (95% confidence interval, 1.20-5.17), 2.48 (95% confidence interval, 0.85-4.10), and 0.77 (95% confidence interval, 0.00-1.64), respectively (P=0.061 from Poisson regression). The number of hospital discharges with a VGS-IE diagnosis in the Nationwide Inpatient Sample database during 1999-2002, 2003-2006, and 2007-2009 ranged between 15 318 to 15 938, 16 214 to 17 433, and 14 728 to 15 479, respectively. CONCLUSIONS: On the basis of data complete through 2010, there has been no perceivable increase in the incidence of VGS-IE in Olmsted County, Minnesota, since the publication of the 2007 American Heart Association endocarditis prevention guidelines.

Periodontal disease and atherosclerotic vascular disease: does the evidence support an independent association?: a scientific statement from the American Heart Association.

A link between oral health and cardiovascular disease has been proposed for more than a century. Recently, concern about possible links between periodontal disease (PD) and atherosclerotic vascular disease (ASVD) has intensified and is driving an active field of investigation into possible association and causality. The 2 disorders share several common risk factors, including cigarette smoking, age, and diabetes mellitus. Patients and providers are increasingly presented with claims that PD treatment strategies offer ASVD protection; these claims are often endorsed by professional and industrial stakeholders. The focus of this review is to assess whether available data support an independent association between ASVD and PD and whether PD treatment might modify ASVD risks or outcomes. It also presents mechanistic details of both PD and ASVD relevant to this topic. The correlation of PD with ASVD outcomes and surrogate markers is discussed, as well as the correlation of response to PD therapy with ASVD event rates. Methodological issues that complicate studies of this association are outlined, with an emphasis on the terms and metrics that would be applicable in future studies. Observational studies to date support an association between PD and ASVD independent of known confounders. They do not, however, support a causative relationship. Although periodontal interventions result in a reduction in systemic inflammation and endothelial dysfunction in short-term studies, there is no evidence that they prevent ASVD or modify its outcomes.

Diagnosis and management of prosthetic joint infection: clinical practice guidelines by the Infectious Diseases Society of America.

These guidelines are intended for use by infectious disease specialists, orthopedists, and other healthcare professionals who care for patients with prosthetic joint infection (PJI). They include evidence-based and opinion-based recommendations for the diagnosis and management of patients with PJI treated with debridement and retention of the prosthesis, resection arthroplasty with or without subsequent staged reimplantation, 1-stage reimplantation, and amputation.

Executive summary: diagnosis and management of prosthetic joint infection: clinical practice guidelines by the Infectious Diseases Society of America.

These guidelines are intended for use by infectious disease specialists, orthopedists, and other healthcare professionals who care for patients with prosthetic joint infection (PJI). They include evidence-based and opinion-based recommendations for the diagnosis and management of patients with PJI treated with debridement and retention of the prosthesis, resection arthroplasty with or without subsequent staged reimplantation, 1-stage reimplantation, and amputation.

Impact of prior aspirin therapy on clinical manifestations of cardiovascular implantable electronic device infections.

AIMS: Cardiovascular implantable electronic device (CIED) infection may present as pocket infection or as infective endocarditis (CIED-IE) with vegetation on device leads or heart valves. As aspirin has both anti-inflammatory properties and interferes with platelet aggregation, we hypothesized that ongoing anti-platelet therapy with aspirin may impact clinical and echocardiographic manifestations of CIED infection. METHODS AND RESULTS: We retrospectively reviewed 415 cases of CIED infection admitted to Mayo Clinic Rochester from 1991 to 2008. Information regarding aspirin use was available in 392 (94.5%) cases and 178 (45%) had received aspirin therapy prior to clinical onset of CIED infection. Although there were no significant differences in pathogen distribution between patients who had received prior aspirin therapy as compared with those who did not, patients on aspirin therapy were less likely to report chills (25% vs. 35%, P = 0.04), sweats (9% vs.18%, P = 0.01), or have peripheral leukocytosis on admission (33% vs. 46%, P = 0.005). Overall, 82 (21%) of 392 patients met the clinical criteria for CIED-IE. Patients on prior aspirin therapy were significantly less likely to have vegetations on CIED leads or heart valves than those who had not received it (15% vs. 26%, P = 0.01). However, despite the lower frequency of CIED-IE in the aspirin group, there was no significant difference (P = 0.97) in the overall survival between the two groups. CONCLUSION: Aspirin therapy prior to onset of CIED infection was associated with a lower likelihood of vegetation formation on CIED leads or heart valves and associated systemic manifestations of infection.