M. Rizwan Sohail

Clinical Manifestations and Management of Left Ventricular Assist Device–Associated Infections

BACKGROUND Infection is a serious complication of left ventricular assist device (LVAD) therapy. Published data regarding LVAD-associated infections (LVADIs) are limited by single-center experiences and use of nonstandardized definitions. METHODS We retrospectively reviewed 247 patients who underwent continuous-flow LVAD implantation from January 2005 to December 2011 at Mayo Clinic campuses in Minnesota, Arizona, and Florida. LVADIs were defined using the International Society for Heart and Lung Transplantation criteria. RESULTS We identified 101 episodes of LVADI in 78 patients (32%) from this cohort. Mean age (± standard deviation [SD]) was 57±15 years. The majority (94%) underwent Heartmate II implantation, with 62% LVADs placed as destination therapy. The most common type of LVADIs were driveline infections (47%), followed by bloodstream infections (24% VAD related, and 22% non-VAD related). The most common causative pathogens included gram-positive cocci (45%), predominantly staphylococci, and nosocomial gram-negative bacilli (27%). Almost half (42%) of the patients were managed by chronic suppressive antimicrobial therapy. While 14% of the patients had intraoperative debridement, only 3 underwent complete LVAD removal. The average duration (±SD) of LVAD support was 1.5±1.0 years. At year 2 of follow-up, the cumulative incidence of all-cause mortality was estimated to be 43%. CONCLUSION Clinical manifestations of LVADI vary on the basis of the type of infection and the causative pathogen. Mortality remained high despite combined medical and surgical intervention and chronic suppressive antimicrobial therapy. Based on clinical experiences, a management algorithm for LVADI is proposed to assist in the decision-making process.

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.

Current concepts in the diagnosis and management of left ventricular assist device infections

Left ventricular assist devices (LVAD) are increasingly being used both as a bridge to transplantation and for long-term myocardial surrogate destination therapy in patients with end-stage heart failure. Primarily owing to the presence of a driveline that connects the device to an external battery through an open skin incision, the rates of LVAD-related infections (LVADRIs) are high, ranging from 30 to 50%. LVADRIs can be broadly classified into driveline infection, pump pocket infection, bloodstream infection and endocarditis/pump or cannula infection. Diagnostic evaluation and management of these complicated infections can be quite challenging for clinicians involved in the care of these patients. Here, the authors summarize the current epidemiology, microbiology, diagnostic approach and management strategies for each type of LVADRI. The authors also review current concepts regarding antibiotic prophylaxis for LVAD implantation. Finally, the authors highlight the gaps in the knowledge of LVADRI and provide directions for future studies.

Adjuvant steroid therapy in community‐acquired pneumonia: A systematic review and meta‐analysis

BACKGROUND Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality among adults. Although steroids appear to be beneficial in animal models of CAP, clinical trial data in humans are either equivocal or conflicting. PURPOSE Our purpose was to perform a systematic review and meta-analysis of studies examining the impact of steroid therapy on clinical outcomes among adults admitted with CAP. DATA SOURCES AND STUDY SELECTION We identified randomized controlled trials (RCTs) through a systematic search of published literature up to July 2011. DATA EXTRACTION We estimated relative risks (RR) and weighted mean differences, pooled from each study using a random effects model. DATA SYNTHESIS Eight RCTs, comprising 1119 patients, met our selection criteria. Overall quality of the studies was moderate. Adjunctive steroid therapy had no effect on hospital mortality or length of stay in the intensive care unit, but reduced the overall length of hospital stay (RR: -1.21 days [95% confidence interval (CI): -2.12 to -0.29]). Less robust data also demonstrated reduced incidence of delayed shock (RR: 0.12 [95% CI: 0.03 to 0.41]) and reduced persistence of chest x-ray abnormalities (RR: 0.13 [95% CI: 0.06 to 0.27]). A priori subgroup and sensitivity analyses did not alter these findings. CONCLUSIONS Moderate-quality evidence suggests that adjunctive steroid therapy for adults hospitalized with CAP reduced the length of hospital stay but did not alter mortality.

Influence of vegetation size on the clinical presentation and outcome of lead-associated endocarditis: Results from the MEDIC registry

OBJECTIVES The purpose of this study was to determine whether the clinical presentation of lead-associated endocarditis (LAE) is related to the size of lead vegetations and how size is related to bacteriology and clinical outcomes. BACKGROUND Cardiac implantable electronic device (CIED) infection may present as either local pocket infection or bloodstream infection with or without LAE. LAE is associated with significant morbidity and mortality. METHODS The clinical presentation and course of LAE were evaluated by the MEDIC (Multicenter Electrophysiologic Device Cohort) registry, an international registry enrolling patients with CIED infection. Consecutive LAE patients enrolled in the MEDIC registry between January 1, 2009 and December 31, 2012 were analyzed. The clinical features and outcomes of 2 groups of patients were compared based on the size of the lead vegetation detected by echocardiography (> or <1 cm in diameter). RESULTS There were 129 patients with LAE enrolled into the MEDIC registry. Of these, 61 patients had a vegetation <1 cm in diameter (Group I) whereas 68 patients had a vegetation ≥1 cm in diameter (Group II). Patients in Group I more often presented with signs of local pocket infection, whereas Group II patients presented with clinical evidence of systemic infection. Staphylococcus aureus was the organism most often responsible for LAE, whereas infection with coagulase-negative staphylococci was associated with larger vegetations. Outcomes were improved among those who underwent complete device removal. However, major complications were associated with an open surgical approach for device removal. CONCLUSIONS The clinical presentation of LAE is influenced by the size of the lead vegetation. Prompt recognition and management of LAE depends on obtaining blood cultures and echocardiography, including transesophageal echocardiography, in CIED patients who present with either signs of local pocket or systemic infection.

Clinical Presentation, Risk Factors, and Outcomes of Hematogenous Prosthetic Joint Infection in Patients with Staphylococcus aureus Bacteremia

BACKGROUND Staphylococcus aureus bacteremia is a life-threatening condition that may lead to metastatic infection, including prosthetic joint infection. METHODS To assess clinical factors associated with hematogenous prosthetic joint infection, we retrospectively reviewed all patients with a joint arthroplasty in place at the time of a first episode of S. aureus bacteremia over a 5-year period at our institution. Patients with postsurgical prosthetic joint infection without hematogenous prosthetic joint infection were excluded. RESULTS There were 85 patients (143 arthroplasties) with either no prosthetic joint infection (n = 50; 58.8%) or hematogenous prosthetic joint infection in at least one arthroplasty (n = 35; 41.2%). The odds of hematogenous prosthetic joint infection was significantly increased among patients with community-acquired S. aureus bacteremia (odds ratio [OR] 18.07; 95% confidence interval [CI] 2.64-infinity; P = .001), as compared with nosocomial S. aureus bacteremia, in which there were no patients with hematogenous prosthetic joint infection. After adjusting for S. aureus bacteremia classification, the presence of ≥3 joint arthroplasties in place was associated with a nearly ninefold increased odds of hematogenous prosthetic joint infection as compared with those with 1-2 joint arthroplasties in place (OR 8.55; 95% CI 1.44-95.71; P = .012). All but one joint with prosthetic joint infection demonstrated at least one clinical feature suggestive of infection. There were 4 additional S. aureus prosthetic joint infections diagnosed during a median of 3.4 years of follow-up post hospitalization for S. aureus bacteremia. CONCLUSION Prosthetic joint infection is frequent in patients with existing arthroplasties and concomitant S. aureus bacteremia, particularly with community-acquired S. aureus bacteremia and multiple prostheses. In contrast, occult S. aureus prosthetic joint infection without clinical features suggestive of prosthetic joint infection at the time of S. aureus bacteremia is rare.

Outcomes and Complications of Lead Removal: Can We Establish a Risk Stratification Schema for a Collaborative and Effective Approach?

Removal of an entire cardiovascular implantable electronic device is associated with morbidity and mortality. We sought to establish a risk classification scheme according to the outcomes of transvenous lead removal in a single center, with the goal of using that scheme to guide electrophysiology lab versus operating room extraction.

Gastrointestinal mucormycosis in immunocompromised hosts.

Invasive mucormycosis is a rare fungal infection in immunocompromised hosts, but it carries a high mortality rate. Primary gastrointestinal disease is the least frequent form of presentation. Early diagnosis and treatment are critical in the management; however, symptoms are typically non‐specific in gastrointestinal disease, leading to delayed therapy. To describe the clinical presentation, diagnosis, treatment and outcomes of gastrointestinal mucormycosis in immunocompromised hosts, we reviewed all cases of primary gastrointestinal mucormycosis in immunocompromised hosts reported in English literature as well as in our Institution from January 1st 1991 to December 31st 2013 for a total of 31 patients. About 52% of patients underwent solid organ transplant (SOT), while the rest had an underlying haematologic malignancy. Abdominal pain was the most common presenting symptom, followed by gastrointestinal bleeding and fever. Gastric disease was more common in SOT, whereas those with haematologic malignancy presented with intestinal disease (P = 0.002). Although gastrointestinal mucormycosis remains an uncommon condition in immunocompromised hosts, it carries significant morbidity and mortality, particularly in cases with intestinal involvement. A high index of suspicion is of utmost importance to institute early and appropriate therapy and improve outcomes.

Incidence, Treatment Intensity, and Incremental Annual Expenditures for Patients Experiencing a Cardiac Implantable Electronic Device Infection: Evidence From a Large US Payer Database 1-Year Post Implantation

Background— Because of the increasing use of cardiac implantable electronic devices (CIEDs), it is important to estimate the incidence and annual healthcare expenditures associated with CIED infections. Methods and Results— Patients with a record of an initial or replacement (full implant or generator only) CIED implant during the calendar years 2009 to 2012 in MarketScan Commercial Claims and Medicare Supplemental database were identified. CIED infections were classified into 4 categories: (1) infection not managed by inpatient admission nor implant removal, (2) infection managed by inpatient admission but no implant removal, (3) infection managed by an implant removal either in an inpatient or in an outpatient setting, and (4) infection with severe sepsis and managed in an inpatient setting with implant removal. Using separate models for initial and replacement cohorts, annualized incidence of infection and incremental annual expenditures by treatment intensity were estimated. Cumulative incidence of infection at 1 year post implant was 1.18% for initial CIED implants and 2.37% for replacement. Median time to infection was 35 days for initial and 23 days for replacement. Incremental healthcare expenditures by treatment intensity categories for initial implant patients at 1 year were

Carbapenem-resistant Enterobacteriaceae and endoscopy: An evolving threat

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