Baddour, L.M.

Abstract Patent foramen ovale (PFO) has a prevalence of approximately 25%. Its association with pyogenic brain abscess (PBA) is unclear. We reviewed adults with PBA and known PFO status from 1 January 2009 through 31 December 2021 at Mayo Clinic. High PFO prevalence (40.5%) was seen. PBA patients with PFO had distinct abscess characteristics but unchanged 1-year, all-cause mortality.

Abstract Background Cardiac implantable electronic device infection (CIEDI) is a serious complication, occurring in approximately 1% of implantations. In addition to antimicrobial therapy, complete device extraction is considered essential for definitive cure. However, this may not always be feasible due to a variety of factors. In select cases, long-term chronic antibiotic suppression (CAS) has been used, yet clinical characteristics and outcomes of patients who received CAS have scarcely been reported. Methods A descriptive study analyzing all adult (age > 18) patients with definite CIEDI who received CAS between 2016 and 2023 across the Mayo Clinic Enterprise (Arizona, Florida, Minnesota, and Upper Midwest) was conducted. Patients with either ventricular assist devices or fungal infection were excluded. Results A total of 321 patients were diagnosed with definite CIEDI during the study period. A total of 37 (8.7%) patients received CAS due to device retention. The median age was 77.5 [IQR 70.5, 87.5] with 32.4% female. Permanent pacemakers were involved in most (64.9%) infections. Approximately one-third (32.4%) of patients had a prosthetic valve. The median time from initial device implantation to CIEDI was 10.6 years [IQR 4.8, 18.1]. CIED-related infective endocarditis was present in 70.3% of cases and 67.6% had lead involvement. The most commonly isolated organisms were Staphylococcus aureus (29.7%), coagulase-negative staphylococci (27%), Enterococcus faecalis (13.5%) and Streptococci (13.5%). Other pathogens or culture-negative cases comprised 16.3%. The primary reason for device retention and CAS was poor surgical candidacy. Doxycycline was the most commonly used agent for CAS, accounting for 37.8% of cases. The average length of suppression was 469.0 days [IQR158.0, 1264.0]. The rate of relapse was 8.1% with all occurring within 90 days of diagnosis. One year mortality was 27.0%. Conclusion CAS may be a feasible option for patients with device retention, although a small proportion experience CIEDI relapse. Unexpectedly, the pathogen distribution among CAS recipients differed from that seen in a general CIED infection population, highlighting selection bias and the distinct clinical characteristics of patients managed with CAS. Disclosures Larry M. Baddour, MD, UpToDate, Inc.: Royalty payments (authorship duties).

Abstract Background Methicillin-susceptible Staphylococcus aureus bacteremia (MS-SAB) is treated with antistaphylococcal penicillins (ASP) or cefazolin. Altered pharmacokinetics in the setting of hypoalbuminemia may reduce the likelihood of therapeutic success in patients receiving highly protein bound beta-lactams. ASPs and cefazolin are 94% and 80% protein bound, respectively. We assessed the impact of hypoalbuminemia (≤2.5 g/dL) on clinical outcomes in patients with MS-SAB treated with ASPs or cefazolin.Table 1:Unweighted and weighted analysis of full cohort by albumin statusTable 2:Weighted analysis of cefazolin and ASP cohorts by albumin status Methods This single center, retrospective study included adults (≥18 years) admitted with community-acquired MS-SAB between 1/1/2006 and 12/31/2019 who received ASPs or cefazolin and had a serum albumin obtained between the date of first culture positivity and 72 hours of definitive therapy. Exclusion criteria included receipt of ≥5 days of MSSA active empiric therapy prior to definitive, polymicrobial bacteremia, antibiotics for an indication other than MS-SAB, or central nervous system infection. The primary outcome was failure to clear blood cultures within 72 hours of definitive therapy initiation. Propensity score weighting was used to adjust for baseline differences between cohorts. Results 160 patients were included with 61 (38.1%) being hypoalbuminemic (Table 1). In the propensity score weighted analysis, the primary outcome occurred in 37% of patients with an albumin ≤2.5 g/dL vs. 10.2% with an albumin >2.5 g/dL (p< 0.001). This finding was consistent in both ASP and cefazolin subgroups (Table 2). Hospital length of stay was longer in hypoalbuminemic patients but did not represent a statistically significant difference in the weighted overall analysis (15.9 vs. 11.6 days, p=0.8). There was no difference in inpatient mortality in any of the cohorts analyzed. 90-day all-cause mortality was higher in hypoalbuminemic patients only in the cefazolin subgroup analysis (20.7% vs 4.9%, p=0.019). Conclusion The presence of hypoalbuminemia was associated with failure to clear blood cultures within 72 hours of definitive therapy initiation in patients with MS-SAB. While no significant difference in mortality was observed overall, the higher mortality in the cefazolin subgroup warrants further research on the impact of hypoalbuminemia on clinical outcomes in patients with MS-SAB. Disclosures Larry M. Baddour, MD, UpToDate, Inc.: Royalty payments (authorship duties).

Abstract INTRODUCTION: Surgical site infection (SSI) is a problematic cause of morbidity following breast/axillary surgery. The breast/axilla has a higher rate of SSI than expected for clean wounds. We evaluated risk factors associated with SSI after breast/axillary operations. Methods: A retrospective review of breast/axillary procedures from July 2004 to July 2006 was performed. SSI was defined using Centers for Disease Control and Prevention criteria, including cases with cellulitis as the only criterion of infection. Data collected included patient demographics, BMI, surgical procedure, ASA class, antibiotic use, drains, and prior radiation (RT). RESULTS: We identified 389 patients who underwent 678 procedures. Thirty-seven SSI (5.5% of procedures) were identified, of which 24 (65%) had only cellulitis. Median time from surgery to SSI diagnosis was 9 days (range 2-112), with 81% occurring in the first 30 days. Univariate analysis identified prior RT, BMI, type of procedure, operative time, use of drain, and postoperative seroma to be associated with SSI (all P<0.05). With multivariate analysis, procedure type remained significant overall (p=0.04). Specifically, mastectomy with sentinel lymph node biopsy (SLNB) and modified radical mastectomy remained significantly associated with higher risk of SSI, with hazard ratios (HR) of 6.3 and 13.5 fold respectively compared to SLNB alone. Seroma (HR 9.0, 95% CI 2.7-29.3), prior RT (HR 3.4, 1.2-9.9), and BMI >=30 (HR 3.1, 1.6-6.2) also remained significantly associated with SSI. CONCLUSION(S): SSI are more frequent after breast/axillary operations than other clean wounds and are associated with prior RT, obesity, more extensive and longer procedures, and postoperative seroma. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-14-10.

Abstract Abstract #3103 Introduction: Lymphedema is well-known in the arm but can also occur in the breast. Diagnosis is currently non-standardized and based on clinical impression. We sought to determine if skin thickness could serve as a useful measure in the diagnosis of breast lymphedema (BLE).
 Methods: Patients undergoing unilateral non-mastectomy procedures were enrolled on this prospective clinical study preoperatively and evaluated for signs and symptoms of lymphedema in the operated breast in the postoperative period. Patients with established BLE were also studied. BLE diagnosis was independent of ultrasound findings and was based on a graded physical exam targeting clinical signs of edema and erythema. Skin thickness was measured with ultrasound at the 6 o'clock position of both breasts. Differences in skin thickness were assessed by the ratio of skin thickness in the operated and contralateral breasts, with comparison of means by two-sample t-test. Receiver operating characteristic curves were constructed to estimate the area under the curve (AUC) and to determine optimal cutpoints.
 Results: Ninety-seven women were studied; 85 were enrolled preoperatively and 12 postoperatively after a diagnosis of BLE. Median length of follow-up overall was 8 months. Of the 97 women, 46 had BLE at one or more follow-up visit with median time to first diagnosis of 3 months. Mean measured skin thickness was 2.3 ± 0.5mm in unaffected breasts and 3.2 ± 1.0 mm in operated breasts. Women with BLE had significantly greater skin thickness in the operated breast compared to the contralateral breast, with a mean skin thickness ratio of 1.83 ± 0.57 in patients with BLE compared to 1.18 ± 0.40 among those without BLE (p<0.0001). Skin thickness ratio provided excellent discrimination for BLE, with an area under the curve (AUC) of 0.86. At a ratio of 1.32 or greater (32% greater skin thickness in operated versus contralateral breast), sensitivity and specificity for diagnosing BLE were 81% and 82% respectively. A single measure of skin thickness in the operated breast also correlated well with diagnosis of BLE, with skin thickness of 3.2 mm or greater demonstrating sensitivity of 78% and specificity of 82%, AUC 0.82.
 Conclusions: Breast lymphedema results in skin edema and increased skin thickness that can be quantified with ultrasound. Measuring breast skin thickness- either as a single reading or as a ratio to the unaffected breast- may be useful in the diagnosis of breast lymphedema. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3103.