Antibacterial Envelope to Prevent Cardiac Implantable Device Infection.

BACKGROUND: Infections after placement of cardiac implantable electronic devices (CIEDs) are associated with substantial morbidity and mortality. There is limited evidence on prophylactic strategies, other than the use of preoperative antibiotics, to prevent such infections. METHODS: We conducted a randomized, controlled clinical trial to assess the safety and efficacy of an absorbable, antibiotic-eluting envelope in reducing the incidence of infection associated with CIED implantations. Patients who were undergoing a CIED pocket revision, generator replacement, or system upgrade or an initial implantation of a cardiac resynchronization therapy defibrillator were randomly assigned, in a 1:1 ratio, to receive the envelope or not. Standard-of-care strategies to prevent infection were used in all patients. The primary end point was infection resulting in system extraction or revision, long-term antibiotic therapy with infection recurrence, or death, within 12 months after the CIED implantation procedure. The secondary end point for safety was procedure-related or system-related complications within 12 months. RESULTS: A total of 6983 patients underwent randomization: 3495 to the envelope group and 3488 to the control group. The primary end point occurred in 25 patients in the envelope group and 42 patients in the control group (12-month Kaplan-Meier estimated event rate, 0.7% and 1.2%, respectively; hazard ratio, 0.60; 95% confidence interval [CI], 0.36 to 0.98; P = 0.04). The safety end point occurred in 201 patients in the envelope group and 236 patients in the control group (12-month Kaplan-Meier estimated event rate, 6.0% and 6.9%, respectively; hazard ratio, 0.87; 95% CI, 0.72 to 1.06; P<0.001 for noninferiority). The mean (±SD) duration of follow-up was 20.7±8.5 months. Major CIED-related infections through the entire follow-up period occurred in 32 patients in the envelope group and 51 patients in the control group (hazard ratio, 0.63; 95% CI, 0.40 to 0.98). CONCLUSIONS: Adjunctive use of an antibacterial envelope resulted in a significantly lower incidence of major CIED infections than standard-of-care infection-prevention strategies alone, without a higher incidence of complications. (Funded by Medtronic; WRAP-IT ClinicalTrials.gov number, NCT02277990.).

Early Clinical Response as a Predictor of Late Treatment Success in Patients With Acute Bacterial Skin and Skin Structure Infections: Retrospective Analysis of 2 Randomized Controlled Trials.

In the treatment of acute bacterial skin and skin structure infections, pooled data from 2 clinical trials (N = 1333 patients) showed that programmatic and investigator-assessed early treatment success both had a high positive predictive value (94.3%-100.0%) for late clinical cure, including among hospitalized patients. The negative predictive value of programmatic early success was <20%. These exploratory findings require prospective real-world evaluation. CLINICAL TRIALS REGISTRATION: NCT01170221; NCT01421511.

Worldwide Randomized Antibiotic EnveloPe Infection PrevenTion Trial (WRAP-IT).

BACKGROUND: Cardiac implantable electronic device (CIED) infection is a major complication that is associated with significant morbidity and mortality. The aim of this study is to determine whether Medtronic TYRX absorbable envelope reduces the risk of CIED infection through 12 months of follow-up post procedure. METHODS: WRAP-IT is a randomized, prospective, multi center, international, single-blinded study. Up to 7,764 subjects who are undergoing CIED generator replacement, upgrade, or revision, or a de novo CRT-D implant, will be enrolled and randomized (1:1) to receive the TYRX envelope or not. The primary endpoint is major CIED infection throughout 12 months of follow up after the procedure. Data will be analyzed with an intention to treat approach. WRAP-IT will also assess the performance of Medtronic's lead monitoring algorithms in subjects whose CIED includes a transvenous right ventricular defibrillation system. CONCLUSIONS: WRAP-IT is a large randomized clinical trial that will assess the efficacy of TYRX absorbable envelope in reducing CIED infection, define its cost effectiveness, and will also provide a unique opportunity to better understand the pathophysiology and risk factors for CIED infection.

Safety, tolerability, and efficacy of GSK1322322 in the treatment of acute bacterial skin and skin structure infections.

GSK1322322 represents a new class of antibiotics that targets an essential bacterial enzyme required for protein maturation, peptide deformylase. This multicenter, randomized, phase IIa study compared the safety, tolerability, and efficacy of GSK1322322 at 1,500 mg twice daily (b.i.d.) with that of linezolid at 600 mg b.i.d. in patients suspected of having Gram-positive acute bacterial skin and skin structure infections (ABSSSIs). The primary endpoint was assessment of the safety of GSK1322322, and a key secondary endpoint was the number of subjects with a ≥20% decrease in lesion area from the baseline at 48 and 72 h after treatment initiation. GSK1322322 administration was associated with mild-to-moderate drug-related adverse events, most commonly, nausea, vomiting, diarrhea, and headache. Adverse events (86% versus 74%) and withdrawals (28% versus 11%) were more frequent in the GSK1322322-treated group. Treatment with GSK1322322 and linezolid was associated with ≥20% decreases from the baseline in the lesion area in 73% (36/49) and 92% (24/26) of the patients, respectively, at the 48-h assessment and in 96% (44/46) and 100% (25/25) of the patients, respectively, at the 72-h assessment. Reductions in exudate/pus, pain, and skin infection scores were comparable between the GSK1322322 and linezolid treatments. The clinical success rates within the intent-to-treat population and the per-protocol population that completed this study were 67 and 91%, respectively, in the GSK1322322-treated group and 89 and 100%, respectively, in the linezolid-treated group. These results will be used to guide dose selection in future studies with GSK1322322 to optimize its tolerability and efficacy in patients with ABSSSIs. (This study has been registered at ClinicalTrials.gov under registration no. NCT01209078 and at http://www.gsk-clinicalstudyregister.com [PDF113414].).

High-dose daptomycin therapy for left-sided infective endocarditis: a prospective study from the international collaboration on endocarditis.

The use of daptomycin in Gram-positive left-sided infective endocarditis (IE) has significantly increased. The purpose of this study was to assess the influence of high-dose daptomycin on the outcome of left-sided IE due to Gram-positive pathogens. This was a prospective cohort study based on 1,112 cases from the International Collaboration on Endocarditis (ICE)-Plus database and the ICE-Daptomycin Substudy database from 2008 to 2010. Among patients with left-sided IE due to Staphylococcus aureus, coagulase-negative staphylococci, and Enterococcus faecalis, we compared those treated with daptomycin (cohort A) to those treated with standard-of-care (SOC) antibiotics (cohort B). The primary outcome was in-hospital mortality. Time to clearance of bacteremia, 6-month mortality, and adverse events (AEs) ascribable to daptomycin were also assessed. There were 29 and 149 patients included in cohort A and cohort B, respectively. Baseline comorbidities did not differ between the two cohorts, except for a significantly higher prevalence of diabetes and previous episodes of IE among patients treated with daptomycin. The median daptomycin dose was 9.2 mg/kg of body weight/day. Two-thirds of the patients treated with daptomycin had failed a previous antibiotic regimen. In-hospital and 6-month mortalities were similar in the two cohorts. In cohort A, median time to clearance of methicillin-resistant S. aureus (MRSA) bacteremia was 1.0 day, irrespective of daptomycin dose, representing a significantly faster bacteremia clearance compared to SOC (1.0 versus 5.0 days; P < 0.01). Regimens with higher daptomycin doses were not associated with increased incidence of AEs. In conclusion, higher-dose daptomycin may be an effective and safe alternative to SOC in the treatment of left-sided IE due to common Gram-positive pathogens.

On the independence of data monitoring committee in adaptive design clinical trials.

In clinical trials, an independent data monitoring committee (DMC) is often established to perform both ongoing safety data monitoring and interim efficacy analysis. These evaluations are performed in a blinded fashion in order to avoid possible operational biases that may be introduced to the trial after the review of the data. The DMCs for clinical trials using adaptive design methods are also positioned to implement the adaptation decision according to the prospective adaptation algorithm. While the DMC plays an important role in maintaining the validity and integrity of the intended clinical trial, adaptive design clinical trials trigger a greater role and increased responsibility for the DMC. To assist the sponsor in establishing a DMC, the U.S. Food and Drug Administration (FDA) published a draft guidance entitled Establishment and Operation of Clinical Trial Data Monitoring Committees in 2006. In this article, the composition, role/responsibility, and function/activity of a DMC are described. Concerns of the additional responsibilities of the DMC for adaptive design clinical trials are addressed. Although the intention of the DMC is well-intentioned, controversial issues inevitably occur. These controversial issues include, but are not limited to, (1) the challenge of the independence of a DMC and (2) the issue regarding the direct communication between the DMC and the FDA. Discussion of controversial issues and practical issues are also provided.

Daptomycin compared to standard therapy for the treatment of native valve endocarditis.

INTRODUCTION: In a recent randomized trial of Staphylococcus aureus bacteremia and native valve endocarditis, daptomycin was found not inferior to standard therapy. We summarized findings in the subgroup of patients with endocarditis according to the Duke criteria. METHODS: Patients were randomly assigned to receive daptomycin 6 mg/kg/day or standard therapy (vancomycin 1g every 12h or antistaphylococcal penicillin 2g every 4h, both with gentamicin 1mg/kg every 8h for the first 4 days). The primary end point was success in the modified intent-to-treat population 6 weeks after the end of therapy. RESULTS: Fifty-three patients were included: 35 with right-sided endocarditis (RIE) and 18 with left-sided endocarditis (LIE). The success rates in patients with RIE were similar between daptomycin and the comparator (42% vs 44%). Patients with RIE with septic pulmonary infarcts responded similarly to treatment with daptomycin and standard therapy (60% vs 67%). In the LIE population, treatment success rates were poor in both arms (11% vs 22%). CONCLUSION: Daptomycin is an efficacious and well-tolerated alternative to standard therapy in the treatment of RIE. Patients with LIE had a poor outcome regardless of the treatment received. Daptomycin is also effective in treating endocarditis with septic pulmonary infarcts.

The World-wide Randomized Antibiotic Envelope Infection Prevention (WRAP-IT) trial: Long-term follow-up.

BACKGROUND: The World-wide Randomized Antibiotic Envelope Infection Prevention trial reported a 40% reduction in major cardiac implantable electronic device (CIED) infections within 12 months of the procedure with the use of an antibacterial-eluting envelope (TYRX Absorbable Antibacterial Envelope, Medtronic, Mounds View, MN). OBJECTIVE: The purpose of this report was to describe the longer-term (>12 months) envelope effects on infection reduction and complications. METHODS: All trial patients who underwent CIED replacement, upgrade, revision, or initial cardiac resynchronization therapy - defibrillator implantation received standard-of-care infection prophylaxis and were randomized in a 1:1 ratio to receive the envelope or not. CIED infection incidence and procedure and system-related complications were characterized through all follow-up (36 months) by using Cox proportional hazards regression modeling. RESULTS: In total, 6800 patients received their intended randomized treatment (3371 envelope; 3429 control; mean follow-up period 21.0 ± 8.3 months). Major CIED-related infections occurred in 32 envelope patients and 51 control patients (Kaplan-Meier [KM] estimate 1.3% vs 1.9%; hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.41-0.99; P = .046). Any CIED-related infection occurred in 57 envelope patients and 84 control patients (KM estimate 2.1% vs 2.8%; HR 0.69; 95% CI 0.49-0.97; P = .030). System- or procedure-related complications occurred in 235 envelope patients and 252 control patients (KM estimate 8.0% vs 8.2%; HR 0.95; 95% CI 0.79-1.13; P < .001 for noninferiority); the most common were lead dislodgment (1.1%), device lead damage (0.5%), and implant site hematoma (0.4%). Implant site pain occurred less frequently in the envelope group (0.1% vs 0.4%; P = .067). There were no (0.0%) reports of allergic reactions to the components of the envelope (mesh, polymer, or antibiotics). CONCLUSION: The effects of the TYRX envelope on the reduction of the risk of CIED infection are sustained beyond the first year postprocedure, without an increased risk of complications.

Comparison of the microbiological efficacy of tedizolid and linezolid in acute bacterial skin and skin structure infections: pooled data from phase 3 clinical trials.

We evaluated the microbiological efficacy of tedizolid compared with that of linezolid against common and emerging pathogens using pooled data from 2 phase 3 trials (NCT01170221 and NCT01421511) in patients with acute bacterial skin and skin structure infections. Patients received tedizolid 200 mg once daily for 6 days (n = 664) or linezolid 600 mg twice daily for 10 days (n = 669). Favorable microbiological outcome in both treatment groups, defined as eradication or presumed eradication at the end of treatment and at the posttherapy evaluation, exceeded 85% for most pathogens, including methicillin-resistant Staphylococcus aureus. Favorable microbiological response was observed for staphylococci and streptococci at tedizolid minimal inhibitory concentration values ≤0.5 mg/L and 0.25 mg/L, respectively. The studies demonstrated positive microbiological outcomes against common pathogens with a 6-day, once-daily regimen of tedizolid phosphate in patients with acute bacterial skin and skin structure infections.

Efficient transplacental IgG transfer in women infected with Zika virus during pregnancy.

Zika virus (ZIKV) is a newly-identified infectious cause of congenital disease. Transplacental transfer of maternal IgG to the fetus plays an important role in preventing many neonatal infections. However, antibody transfer may also have negative consequences, such as mediating enhancement of flavivirus infections in early life, or trafficking of virus immune complexes to the fetal compartment. ZIKV infection produces placental pathology which could lead to impaired IgG transfer efficiency as occurs in other maternal infections, such as HIV-1 and malaria. In this study, we asked whether ZIKV infection during pregnancy impairs transplacental transfer of IgG. We enrolled pregnant women with fever or rash in a prospective cohort in Vitoria, Brazil during the recent ZIKV epidemic. ZIKV and dengue virus (DENV)-specific IgG, ZIKV and DENV neutralizing antibodies, and routine vaccine antigen-specific IgG were measured in maternal samples collected around delivery and 20 paired cord blood samples. We concluded that 8 of these mothers were infected with ZIKV during pregnancy and 12 were ZIKV-uninfected. The magnitude of flavivirus-specific IgG, neutralizing antibody, and vaccine-elicited IgG were highly correlated between maternal plasma and infant cord blood in both ZIKV-infected and -uninfected mother-infant pairs. Moreover, there was no difference in the magnitude of plasma flavivirus-specific IgG levels between mothers and infants regardless of ZIKV infection status. Our data suggests that maternal ZIKV infection during pregnancy does not impair the efficiency of placental transfer of flavivirus-specific, functional, and vaccine-elicited IgG. These findings have implications for the neonatal outomes of maternal ZIKV infection and optimal administration of antibody-based ZIKV vaccines and therapeutics.

Genotypic characteristics of Staphylococcus aureus isolates from a multinational trial of complicated skin and skin structure infections.

The impact of bacterial genetic characteristics on the outcome of patients with Staphylococcus aureus infections is uncertain. This investigation evaluated potential associations between bacterial genotype and clinical outcome using isolates collected as part of an international phase 2 clinical trial (FAST II) evaluating telavancin for the treatment of complicated skin and skin structure infections (cSSSI). Ninety S. aureus isolates from microbiologically evaluable patients with cSSSI enrolled in the FAST II trial from 11 sites in the United States (56 isolates, or 62%) and 7 sites in South Africa (34 isolates, or 38%) were examined for staphylococcal cassette chromosome mec, agr, and the presence of 31 virulence genes and subjected to pulsed-field gel electrophoresis (PFGE). South African methicillin-susceptible S. aureus (MSSA) isolates were more likely to carry certain virulence genes, including sdrD (P = 0.01), sea (P < 0.01), and pvl (P = 0.01). All 44 (49%) methicillin-resistant S. aureus (MRSA) isolates were from the United States; 37 (84%) were strain USA 300 by PFGE. In the United States, MRSA isolates were more likely than MSSA isolates to carry genes for sdrC (P = 0.03), map/eap (P = 0.05), fnbB (P = 0.11), tst (P = 0.02), sea (P = 0.04), sed (P = 0.04), seg (P = 0.11), sej (P = 0.11), agr (P = 0.09), V8 (P = 0.06), sdrD, sdrE, eta, etb, and see (P < 0.01 for all). MRSA isolates were more often clonal than MSSA isolates by PFGE. Isolates from patients who were cured were significantly more likely to contain the pvl gene than isolates from patients that failed or had indeterminate outcomes (79/84 [94%] versus 3/6 [50%]; P = 0.01). S. aureus strains from different geographic regions have different distributions of virulence genes.

Safety of Delafloxacin: Focus on Adverse Events of Special Interest.

BACKGROUND: Fluoroquinolones have been widely used for a variety of Gram-positive and Gram-negative infections, and by 2002 they had become the most commonly prescribed class of antibiotics for adults in the United States. With widespread use, the class has become associated with a range of adverse events. Delafloxacin is a fluoroquinolone approved in the United States for the treatment of adults with acute bacterial skin and skin structure infections (ABSSSIs). Delafloxacin is differentiated from other fluoroquinolones due to structural differences and in its activity against methicillin-resistant Staphylococcus aureus, including quinolone-resistant strains. This paper reviews the safety profile of delafloxacin across clinical studies with an emphasis on the incidence of adverse events of special interest that are associated with fluoroquinolones. METHODS: Data from 2 completed phase III studies of delafloxacin for the treatment of ABSSSIs were pooled and are the primary focus of this paper. Additional support from the full safety analysis set (30 completed phase I to phase III clinical studies) is included where applicable. RESULTS: Fewer patients in the pooled delafloxacin group had AESIs than in the comparator group (7.0% vs 9.2%, respectively). Delafloxacin had a low rate of discontinuations due to treatment-related adverse events (<1%). Serious adverse events occurred at similar rates in patients treated with delafloxacin vs comparators. CONCLUSIONS: Serious adverse events occurred at similar rates in patients treated with delafloxacin vs nonquinolone comparators used to treat ABSSSIs. CLINICALTRIALSGOV IDENTIFIER: NCT01984684 and NCT01811732.

Clinical characteristics and outcome of aortic endocarditis with periannular abscess in the International Collaboration on Endocarditis Merged Database.

The aims of this study were to determine the clinical characteristics and outcome of patients who had definite infective endocarditis (IE) complicated by aortic ring abscess formation that was detected with transesophageal echocardiography (TEE) and to determine the prognostic significance of abscess formation in aortic valve IE. Patients who had aortic valve IE were selected from the International Collaboration on Endocarditis Merged Database (ICE-MD) if they underwent TEE. Among 311 patients who had definite aortic valve IE, 67 (22%) had periannular abscesses. They were more likely to have infection in the setting of a prosthetic valve (40% vs 19%, p <0.001) and coagulase-negative staphylococcal IE (18% vs 6%, p < 0.01) and less likely to have streptococcal IE than were patients who did not develop abscess (28% vs 46%, p = 0.01). Systemic embolization, central nervous system events, and heart failure did not differ between those who developed abscess and those who did not, but power was limited. Patients who had abscess were more likely to undergo surgery (84% vs 36%, p <0.001), and their in-hospital mortality rate was higher (19% vs 11%, p = 0.09). Multivariate analysis of prognostic factors of mortality in aortic IE identified age (odds ratio [OR] 1.6, 95% confidence interval [CI]1.2 to 2.1), Staphylococcus aureus (S. aureus) infection (OR 2.4, 95% CI 1.1 to 5.2), and heart failure (OR 2.9, 95% CI 1.4 to 6.1) as variables that were independently associated with increased risk of death. Periannular abscess formation showed a nonsignificant trend toward an increased risk of death (OR 1.9, 95% CI 0.9 to 3.8). Multivariate analysis of prognostic factors of mortality in complicated aortic IE with abscess formation identified S. aureus infection (OR 6.9, 95% CI 1.6 to 29.4) as independently associated with increased risk of death. In conclusion, in the current era of TEE and high use of surgical treatment, periannular abscess formation in aortic valve IE is not an independent risk factor for mortality. S. aureus infection is an independent prognostic factor for mortality in patients who have abscess formation.

Performance of recombinant K39 antigen in the diagnosis of Brazilian visceral leishmaniasis.

This study evaluated the performance of recombinant K39 (rK39) antigen in a immunochromatographic format (strip test) and a crude antigen enzyme-linked immunosorbent assay in the diagnosis of Brazilian visceral leishmaniasis (VL) in 128 consecutive patients with parasitologically proven infections (by microscopy and/or culture). For each patient, a medical history was obtained and a complete physical examination was performed. Controls included 10 healthy volunteers and 50 patients with other diseases: malaria (10), leprosy (9), Chagas' disease (10), tuberculosis (10), and cutaneous leishmaniasis (11). The sensitivities of the rK39 antigen strip test and the ELISA were 90% and 89%, respectively, while the specificities were 100% and 98%, respectively. Our study confirms the accuracy of the rK39 antigen strip test in the diagnosis of VL in a high prevalence population.

Benefits, challenges and obstacles of adaptive clinical trial designs.

In recent years, the use of adaptive design methods in pharmaceutical/clinical research and development has become popular due to its flexibility and efficiency for identifying potential signals of clinical benefit of the test treatment under investigation. The flexibility and efficiency, however, increase the risk of operational biases with resulting decrease in the accuracy and reliability for assessing the treatment effect of the test treatment under investigation. In its recent draft guidance, the United States Food and Drug Administration (FDA) expresses regulatory concern of controlling the overall type I error rate at a pre-specified level of significance for a clinical trial utilizing adaptive design. The FDA classifies adaptive designs into categories of well-understood and less well-understood designs. For those less well-understood adaptive designs such as adaptive dose finding designs and two-stage phase I/II (or phase II/III) seamless adaptive designs, statistical methods are not well established and hence should be used with caution. In practice, misuse of adaptive design methods in clinical trials is a concern to both clinical scientists and regulatory agencies. It is suggested that the escalating momentum for the use of adaptive design methods in clinical trials be slowed in order to allow time for development of appropriate statistical methodologies.

Tick-borne disease.

Tick-borne diseases in the United States include Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, tularemia, babesiosis, Colorado tick fever, and relapsing fever. It is important for family physicians to consider these illnesses when patients present with influenza-like symptoms. A petechial rash initially affecting the palms and soles of the feet is associated with Rocky Mountain spotted fever, whereas erythema migrans (annular macule with central clearing) is associated with Lyme disease. Various other rashes or skin lesions accompanied by fever and influenza-like illness also may signal the presence of a tick-borne disease. Early, accurate diagnosis allows treatment that may help prevent significant morbidity and possible mortality. Because 24 to 48 hours of attachment to the host are required for infection to occur, early removal can help prevent disease. Treatment with doxycycline or tetracycline is indicated for Rocky Mountain spotted fever, Lyme disease, ehrlichiosis, and relapsing fever. In patients with clinical findings suggestive of tick-borne disease, treatment should not be delayed for laboratory confirmation. If no symptoms follow exposure to tick bites, empiric treatment is not indicated. The same tick may harbor different infectious pathogens and transmit several with one bite. Advising patients about prevention of tick bites, especially in the summer months, may help prevent exposure to dangerous vector-borne diseases.