Lahr, Brian D.

Abstract Background The optimal duration of antibiotic therapy after debridement and implant retention (DAIR) for periprosthetic joint infections (PJIs) is debated. Furthermore, the best antibiotic regimens for staphylococcal PJI are also unclear. In this study, we evaluated the impact of antibiotic therapy duration on the risk of failure. We assessed the utility of rifampin-based regimens for staphylococcal PJI managed with DAIR. Methods We performed a retrospective cohort study of patients 18 years and older diagnosed with hip and knee PJI who underwent DAIR between January 1, 2008 and 31 December 31, 2018 at Mayo Clinic, USA. The outcome was failure of DAIR. For statistical analysis, joint-stratified Cox regression models adjusted for age, sinus tract, symptom duration, and primary/revision arthroplasty were performed. Results We examined 247 cases of PJI with a median follow-up of 4.4 years (interquartile range [IQR], 2.3–7) after DAIR. The estimated 5-year cumulative incidence of failure was 28.1% (n = 65). There was no association between the duration of intravenous (IV) antibiotics (median 42 days; IQR, 38–42) and treatment failure (P = .119). A shorter duration of subsequent oral antibiotic therapy was associated with a higher risk of failure (P = .005; eg, 90-day vs 1-year duration; hazard ratio [HR], 3.50; 95% confidence interval [CI], 1.48–8.25). For staphylococcal knee PJI, both the use and longer duration of a rifampin-based regimen were associated with a lower risk of failure (both P = .025). There was no significant association between fluoroquinolone (FQ) use and failure (HR, 0.62; 95% CI, .31–1.24; P = .172). Conclusions The duration of initial IV antibiotic therapy did not correlate with treatment failure in this cohort of patients. Rifampin use is recommended for staphylococcal knee PJI. There was no apparent benefit of FQ use in staphylococcal PJI.

Abstract OBJECTIVES This study analyzes the safety and outcomes of mitral valve repair for degenerative mitral valve regurgitation in patients 75 years of age or older. METHODS We retrospectively reviewed the clinical results of 343 patients aged ≥75 years who underwent mitral valve repair for degenerative mitral valve regurgitation as a primary indication between January 1998 and June 2017. RESULTS The median (interquartile range) age of the patients was 79.4 (76.9, 82.9) years, and 132 (38.5%) patients were women. Concomitant procedures were performed in 123 patients: tricuspid surgery in 68 (19.8%) and a maze procedure or pulmonary vein isolation in 55 (16.0%). Operative mortality was 1.2%. Operative complications included atrial fibrillation in 37.9%, prolonged ventilation in 7.0%, pacemaker implantation in 3.8, renal failure requiring dialysis in 1.5 and stroke in 3 (0.9%). The median follow-up was 7.4 years (interquartile range, 3.5–14.1 years). The cumulative incidence rates of mitral valve reoperation were 2.2%, 3.2% and 3.2% at 1, 5 and 10 years, respectively. Overall survival at 1, 5 and 10 years were 95%, 83% and 51%, respectively. Older age, smoking and over and underweight were associated with increased risk of mortality, while higher left ventricular ejection fraction and hypertension were associated with reduced risk. CONCLUSIONS Mitral valve repair in elderly patients can be accomplished with low operative mortality and complications. Mitral valve repair in the elderly remains the preferred treatment for degenerative mitral regurgitation.

Abstract Background Population-based studies of Staphylococcus aureus bacteremia (SAB) in the United States are limited. We provide a contemporary evaluation of SAB incidence in Olmsted County, Minnesota, from 2006 to 2020. Methods This was a retrospective population-based study of all adult patients with SAB residing in Olmsted County from 1 January 2006 through 31 December 2020. Initial episodes of SAB were identified using the microbiology laboratory databases at both Olmsted Medical Center and Mayo Clinic Rochester. Results Overall, 541 incident SAB cases were identified with a median age of 66.8 (interquartile range, 54.4–78.5) years, and 60.4% were male. Among these cases, 298 (56.2%) were due to methicillin-susceptible S aureus (MSSA) and 232 (43.8%) cases of methicillin-resistant S aureus (MRSA). The overall age- and sex-adjusted SAB incidence rate (IR) was 33.9 (95% confidence interval [CI], 31.0–36.8) cases/100 000 person-years (PY). Males had a higher age-adjusted IR of 46.0 (95% CI, 41.0–51.0) cases/100 000 PY compared to females (IR, 24.4 [95% CI, 21.1–27.7] cases/100 000 PY). Age- and sex-adjusted SAB IRs due to MSSA and MRSA were 18.7 and 14.6 cases/100 000 PY, respectively, and the percentage of incident SAB cases due to MRSA fluctuated across the study period. There was no apparent temporal trend in SAB incidence over the study period (P = .093). Conclusions Our investigation represents the only contemporary population-based study in the United States. Despite the impression that SAB incidence may have increased based on Centers for Disease Control and Prevention surveillance data, our finding of no change in SAB incidence was somewhat unanticipated.

Abstract OBJECTIVES The purpose of this study was to assess the safety and efficacy of direct cannulation of the ascending aorta in comparison with cannulating peripheral arteries. METHODS We retrospectively analysed type A dissection patients [n = 107; median (interquartile range [IQR]) age, 64 [53–73] years] from January 2008 to March 2018. The cohort was divided into 2 groups: direct ascending aorta cannulation (group A, n = 47; median [IQR] age, 69 [54–74] years; 34% female) and non-aortic cannulation (group B, n = 60; median [IQR] age, 62 [52–72] years; 20% female). Postoperative outcomes and long-term survival were compared. RESULTS Baseline characteristics were not significantly different between the 2 groups, except for higher creatinine in group B (median 0.9 vs 1.1, P = 0.028) and higher prevalence of dyslipidaemia in group A (58.7% vs 38.3%, P = 0.037). Overall early mortality was 12.1% (n = 13); 12.8% (n = 6) in group A and 11.7% (n = 7) in group B (P = 0.863). The incidence of stroke was 10.6% (n = 5) in group A and 6.7% (n = 4) in group B (P = 0.463). After adjusting for CPB and circulatory arrest times, there was no group difference in the length of ICU (P = 0.257) or hospital stay (P = 0.118), all-cause reoperation (P = 0.709), peak postoperative creatinine (P = 0.426) and lactate values (n = 60; P = 0.862). Overall survival at 1, 3 and 5 years was 84%, 78% and 73%, respectively, with no difference between the 2 groups after adjustment (P = 0.629). CONCLUSIONS Direct cannulation of the ascending aorta is a safe cannulation strategy for type A dissection repair, offering the opportunity for rapid arterial cannulation and antegrade perfusion.

Background: Cardiac rehabilitation (CR) improves functional capacity after heart valve surgery (HVS), but no survival benefit has yet been described. We hypothesized that attendance at CR after HVS would be associated with improved long-term survival. Methods: In 2013, we surveyed all patients (or a close family member if the patient was deceased) who had isolated HVS between 2006 through 2010 at the Mayo Clinic to assess if they attended CR after their HVS. We assessed survey reliability among local patients by comparing self-reported vs. medical-record verified CR attendance with the kappa statistic. We then performed a propensity-adjusted landmark mortality analysis through October 2014 for the association between CR attendance and long-term all-cause mortality conditional upon surviving the first year after HVS. Results: Survey response rate was 40% (573/1420), with responders more likely to be older, have longer hospitalizations, more aortic valve disease, but have better survival than non-responders. Among local patients, there was “substantial” agreement between reported attendance and medical-record verified CR attendance (agreement at 84%, kappa = 0.62.) A total of 547 patients (age 70 yrs., 62% male, 59% aortic valve surgery) with valid survey responses were included in the propensity analysis, of whom 296 (54.1%) attended CR. There were 100 deaths during a median follow-up of 5.4 years. For all patients, the propensity-adjusted model suggested no impact of CR on mortality (HR 1.03, 95% CI, 0.66 to 1.62). When stratified by procedure type, results suggested a potentially favorable, but non-significant, effect among patients with mitral valve surgery (HR 0.49, 95% CI 0.15 to 1.56), but not among patients with aortic valve surgery (HR 1.00, 95% CI 0.61 to 1.64.) Conclusions: Important improvements in functional capacity from CR have been previously reported after HVS, but, contrary to our hypothesis, we found that CR does not provide long-term survival benefits after HVS. These findings need additional confirmation to better clarify any mortality impact that may exist for CR following HVS, particularly among patients undergoing mitral valve surgery.

Abstract Background Debridement, antibiotics, and implant retention (DAIR) is appropriate for select acute postoperative and hematogenous periprosthetic joint infections (PJIs). However, the optimal duration of antimicrobial therapy in patients treated with DAIR has not been defined. Therefore, we aimed to identify the ideal duration of parenteral and oral antibiotics after DAIR. Methods We performed a retrospective study of patients >18 years of age with hip or knee PJI managed with DAIR between January 1, 2008, and December 31, 2018, at Mayo Clinic. PJI was defined using criteria adapted from the International Consensus Meeting on PJI. The outcome was defined as either PJI recurrence or unplanned reoperation due to infection. Joint-stratified Cox proportional hazards regression models with time-dependent covariates were used to assess nonlinear effects of antibiotic duration. Hazard ratios were computed based on prespecified time points for comparison, whereas p-values represented the overall effect across the entire range of durations. Results There were 247 unique episodes of PJI in 237 patients during the study period. Parenteral antibiotics were given in 99.2% of cases (n=245). This was followed by chronic oral antibiotic suppression in 92.2% (n=226) with a median duration of 2.2 years (1.0-4.1). DAIR failed in 65 cases over a median follow-up of 4.4 years, with a 5-year cumulative incidence of 28.1%. After adjustment for risk factors, there was no significant association between duration of parenteral antibiotics and treatment failure (p=0.203), with no difference between four versus six weeks (HR 1.11; 95% CI 0.71-1.75) (Figure 1). However, both use and longer duration of oral antibiotic therapy was associated with a lower risk of failure (p=0.006). To account for the possibility that this association was driven by results during early follow-up, conditional analyses at one- and two-year follow-up were performed. Both showed a significantly lower risk for a longer duration of antibiotics (Figure 2). Figure 1. Time-Dependent Analysis of Parenteral Antibiotic Duration Figure 2. Time-Dependent Analysis of Oral Antibiotic Suppression Duration Conclusion After DAIR, efficacy from four weeks of parenteral antibiotics was no different from six weeks when followed by chronic oral antibiotic suppression. Our results could not establish an optimal duration but suggested that continuing suppression portends a lower risk of failure of DAIR. Disclosures Elie Berbari, MD, Uptodate.com (Other Financial or Material Support, Honorary unrelated to this work) Matthew P. Abdel, MD, Stryker and AAOS Board of Directors (Board Member, Other Financial or Material Support, Royalties) Aaron J. Tande, MD, UpToDate.com (Other Financial or Material Support, Honoraria for medical writing)

Abstract Background Serial blood cultures are integral in managing Staphylococcus aureus bacteremia (SAB) as clinicians rely on the results to determine infectious complication risks and antibiotic duration. Current IDSA guidelines suggest a single set of negative blood cultures is adequate evidence of SAB clearance. Several studies, however, have identified the skip phenomenon (SP), which is the occurrence of intermittent negative blood cultures, and have recommended obtaining additional blood cultures to document bacterial clearance (Table 1). We therefore examined patients who manifested the SP to determine its clinical significance and to study this, associations were tested for SP in relation to various baseline factors as well as clinical outcomes. Methods We performed a retrospective, multicenter study of all patients with a positive blood culture for S. aureus from January 2019 to December 2019 using data collected from electronic health records and the clinical microbiology laboratory. Results A total of 602 patients with SAB were identified and 495 patients were included in the investigation (Figure 1). Overall, 25 (5.1%) patients had the SP. Significant differences between those who did and did not manifest the SP included higher rates of injection drug use, automatic implantable cardioverter defibrillator, and community onset of infection in the SP cohort (Table 2). Moreover, the median duration of SAB was longer (3.2 [2.3-5.4] vs 1.90 [1.2-2.9] days, p=0.002), and high-grade SAB, (88.0% vs 58.7%, p=0.004), complicated bacteremia (92.0% vs 67.9%, p=0.011) and IE diagnosis (28.0% vs 11.3%, p=0.013) were all more common in the SP group. In unadjusted outcome analyses, association of SP with hospital length of stay was not significant, although a higher risk of in-hospital mortality among SP patients approached statistical significance (p=0.055). Analysis of 435 hospital survivors revealed no significant differences in rates of 1-year mortality or 90-day relapse between the two groups (Table 3). Conclusion Findings of the current investigation demonstrates an increased risk of SAB complications in patients with the SP and support the notion that serial negative blood cultures are needed to document clearance of SAB. Disclosures Larry M. Baddour, MD, Boston Scientific (Individual(s) Involved: Self): Consultant; Botanix Pharmaceuticals (Individual(s) Involved: Self): Consultant; Roivant Sciences (Individual(s) Involved: Self): Consultant Muhammad R. Sohail, MD, Medtronic (Consultant)Philips (Consultant)

Abstract Background Invasive fungal infection (IFI) in heart transplant recipients is associated with poor outcomes. Estimated risk of 1‐year IFI in heart transplant recipients is 3.4–8.6% with risk factors inconsistently identified in previous studies. The role of antifungal prophylaxis is unclear. The transplant program at Mayo Clinic provides 6 months of universal azole prophylaxis for those heart transplant recipients in Arizona. We sought to define risk factors for 1‐year IFI and determine the effect of antifungal prophylaxis. Methods We conducted a retrospective cohort study of patients undergoing heart transplantation at Mayo Clinic from January 2000 to March 2019. We analyzed demographics, details of transplant hospitalization, antifungal prophylaxis, and fungal infection. Multivariable Cox analyses were performed to identify risk factors of 1‐year IFI and impact of IFI on posttransplant mortality. Results A total of 966 heart transplant recipients were identified with a median age of 56 years (IQR 47, 62). A total of 444 patients received antifungal prophylaxis. Over 1‐year follow‐up, 62 patients developed IFI with a cumulative incidence of 6.4%. In multivariable analysis, factors associated with IFI were renal replacement therapy (RRT) (HR 3.24, 95% CI 1.65–6.39), allograft rejection (HR 2.33, 95% CI 1.25–4.34), and antifungal prophylaxis (HR 0.32, 95% CI 0.11–0.96). RRT was also associated with invasive mold infection (HR 3.00, 95% CI 1.29–6.97). Conclusions RRT and allograft rejection after transplantation are associated with 1‐year IFI, and RRT is also associated with invasive mold infection. Antifungal prophylaxis appears to be protective and further study is needed in the heart transplant population.

Background: In 2007, the American Heart Association (AHA) infective endocarditis (IE) prevention guidelines recommended that antibiotic prophylaxis before invasive dental procedures for the “moderate risk” (MR) group, which represented the bulk of patients who were to receive prophylaxis before 2007, be eliminated. This decision was met with much concern among some healthcare providers and that concern persists today. We therefore evaluated dental office records in Olmsted County (OC), Minnesota to determine whether patients included in the MR group continue to receive antibiotic prophylaxis despite the 2007 AHA recommendations. Methods: Eligible patients include all adult (≥18 years) residents of OC, classified as having MR cardiac condition for IE (i.e. mitral valve prolapse [MVP], bicuspid aortic valve [BAV], hypertrophic obstructive cardiomyopathy [HOCM], acquired valvular dysfunction [AVD]), with at least one dental visit between January 1, 2005 and June 1, 2015. Eight dental offices located within OC were sampled to identify both dental procedures and whether antibiotic prophylaxis was administered according to AHA guidelines. Results: We identified 334 MR patients. Approximately 62% of MR patients received antibiotic prophylaxis prior to the change in AHA guidelines in 2007. There was a decrease to 7% post-2007 AHA guidelines (P<.001). The magnitude of decline was greater among visits for dental cleanings (from 63% to 6%), as compared to other invasive procedures (57% to 11%; P=0.003) (Figure 1). AVD was the most common cardiac condition (85%), followed by MVP (8%), and BAV (4%). Conclusion: Following publication of the 2007 AHA IE prevention guidelines, there was a rapid, 9-fold decrease in antibiotic prophylaxis in patients with MR cardiac conditions who underwent invasive dental procedures in OC. These data are also critical as we attempt to evaluate the impact, if any, of this practice on the incidence of IE due to viridans group streptococci.