P-1711. Attributable and Contributable Mortalities of Culture-Positive Invasive Aspergillosis in Unselected Patients with Hematologic Malignancies at a Tertiary Care Cancer Center: No Room for Complacency
Abstract Background Invasive aspergillosis (IA) remains a common cause of both direct and contributable mortality in patients with hematologic malignancies (HM). Given the advances in antifungal management, it would be important to assess IA-attributable mortality (AM) and contributable mortality (CM), in addition to overall mortality (OM). Methods We retrospectively reviewed the records of 76 consecutive HM patients with proven/probable culture-positive IA (MSG/EORTC criteria) from 2015 to 2021. Death causality was adjudicated based on published criteria. AM was defined as death “due to” IA, while CM as death “due to” and “with” IA. OM encompassed death from any cause. Mortality rates and death causalities were evaluated at 2-, 4-, 6-, and 12-week intervals following IA diagnosis. A multivariate competing risk analysis was performed to identify independent risk factors for 6-week AM, with other death causalities as the competing event. To increase diagnostic accuracy, we excluded culture-negative, Aspergillus galactomannan (GM) positive cases, as GM can be produced by other hyalohyphomycetes. Results The median patient age was 60 years (61%). Lymphoma and multiple myeloma (L/MM) were the most common HM (40, 53%). The remaining patients had active leukemia. Twenty-nine patients (38%) had prior stem cell transplantation, and 10 (13%) had graft-versus-host disease. Aspergillus fumigatus was the most common species (47%). Six and 12-week mortality rates were 18.7% and 22.7% for AM, 42.7% and 49.3% for CM, and 45.3% and 53.3% for OM, respectively. Notably, 2-week OM was 27.6%. Lack of neutrophil recovery was the only independent risk factor for 6-week AM on multivariate analysis (OR=4.2, p=0.006). Conclusion Our findings reflect the modern reality of culture-documented IA, occurring mostly in HM patients with heavily pretreated L/MM not routinely receiving mold-active prophylaxis, and in those with active leukemia. In this real-life contemporary HM population, culture-positive IA was associated with high cumulative OM and CM. Understanding AM and CM rates could lead to more accurate sample size estimations in clinical mycology trials. Such trials should be pragmatic and assess antifungal failure at an earlier time point than the traditional 4-week mark post-diagnosis. Disclosures Dimitrios P. Kontoyiannis, MD, AbbVie, Inc: Advisory Board Participation|Astellas: Grant/Research Support|Basilea: Advisor/Consultant|Cidara, Inc: Advisory Board Participation|F2G, Inc: Advisor/Consultant|Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Knight, Inc: Honoraria|Pfizer: Advisor/Consultant|Scynexis: Advisor/Consultant|TTF Pharmaceuticals, Inc: Advisor/Consultant|US-Israel Binational Sci Foundation: Grant/Research Support
300. Clinical Manifestations and Risk Factors for Treatment Failure in Native Vertebral Osteomyelitis: A 25-Year Multicenter Mayo Clinic Experience
Abstract Background Native vertebral osteomyelitis (NVO) is a life-threatening spinal infection with considerable clinical burden. Although increasing literature has described its features and associated treatment failure, large-scale cohorts with long-term follow-up remain limited. Herein, we evaluated a large cohort of patients with NVO to characterize the clinical manifestations, management, and long-term outcomes, and to further explore factors associated with treatment failure.Table 1.Baseline characteristics of patients with native vertebral osteomyelitisTable 2.Treatment, failure rates, and mortality in patients with native vertebral osteomyelitis Methods We conducted a retrospective multicenter cohort study of adults (≥18 years) with NVO across Mayo Clinic sites between 1999 and 2024. Data on demographics, clinical manifestations, antimicrobial therapy, and surgical intervention were collected. Cumulative incidence of treatment failure was estimated as a function of follow-up accounting for the competing risk of death. Independent predictors of treatment failure were evaluated in a multivariable Cox regression model with time-dependent covariates.Table 3.Multivariable predictors of treatment failure in patients with native vertebral osteomyelitisFigure 1.Cumulative incidence of death and treatment failure following diagnosis of native vertebral osteomyelitis(A) Short-term (12-month) cumulative incidence of death and treatment failure (magnified view of the first year from panel B).(B) Long-term (up to 7 years) cumulative incidence of death (dotted orange line) and treatment failure (solid blue line). Results Among 1,255 patients included (median age 67 years; 66% male), lumbosacral involvement was most common (65%), with multilevel vertebral involvement ( >2 levels) in 21%. Epidural abscesses were present in 43%, paravertebral abscesses in 42%, and psoas abscesses in 20%. Pathogens were identified in 77%, most commonly S. aureus (50%; MSSA 37%, MRSA 13%), followed by Streptococcus species (22%), and Gram-negative bacilli (11%) (Table 1). The median total antibiotic duration was 59 days (IQR, 42–132). Surgical intervention was performed in 13% after a median of 2 days (IQR, 1-5). Treatment failure occurred in 162 patients during a median follow-up of 2.8 years (6-month and 5-year cumulative incidence were 11% and 14%, respectively), with the median time to failure of 3.1 months. Cumulative mortality was 12% at 6 months and 33% at 5 years (Table 2, Figure 1). Diabetes (HR 1.90, 95% CI 1.16–3.12), multilevel vertebral involvement (HR 1.75, 95% CI 1.22–2.51), and MRSA infection (HR 2.11, 95% CI 1.06–4.18) were independently associated with increased risk of treatment failure (Table 3). Conclusion This 25-year study highlights the persistent burden of treatment failure in NVO and associated risk factors, underscoring the importance of early recognition of high-risk features to optimize outcomes. Disclosures All Authors: No reported disclosures
299. Consequences of Delaying Surgical Intervention in Patients with Native Joint Septic Arthritis
Abstract Background Native joint septic arthritis (NJSA) is a serious musculoskeletal infection requiring timely surgical intervention to prevent long-term morbidity. Although current guidelines recommend early surgical debridement, supporting data, particularly on long-term outcomes, remain scarce. Given this, we evaluated the association between surgical timing and 1-year clinical outcomes using the Desirability of Outcome Ranking (DOOR) framework, applied for the first time in NJSA.Table 1.Desirability of Outcome Ranking (DOOR) ordinal scaleTable 2.Baseline demographic, clinical characteristics, and treatment outcomes Methods We conducted a retrospective multicenter cohort study of adults (≥18 years) with NJSA who underwent surgery across Mayo Clinic campuses between 2012 and 2021. Clinical outcomes at one year were assessed using a 9-level DOOR scale, incorporating survival, treatment failure (relapse, reinfection, readmission, or significant surgical events), and joint recovery (full vs qualified) (Table 1). Time to surgery from hospital admission was analyzed both as a continuous variable and as categories: < 1, 1–2, or ≥3 days.Table 3.Associations between duration and outcomesFigure 1.Association Between Time to Surgery and DOOR Scores in Native Joint Septic Arthritis.A) Distribution of Modified DOOR Scores by Surgical Timing. B) Modeled Probability of DOOR Scores by Time to Surgery. Results Among 268 patients (median age 62 years, 61% male), 30% underwent surgery < 1 day from admission, 47% within 1–2 days, and 24% at ≥3 days. At 1 year, 57% achieved full recovery without unfavorable events (DOOR score 1), while treatment failure occurred in 34% (Table 2). In unadjusted analyses, longer surgical delay was significantly associated with higher DOOR scores (per IQR increase [from 0 to 2 days], OR: 1.5; 95% CI: 1.0–2.1; p = 0.026) and with increased 1-year mortality (HR: 1.7; 95% CI: 1.1–2.6; p = 0.019) and treatment failure (HR: 1.5; 95% CI: 1.1–2.0; p = 0.007). Similar results were obtained when delay was used as a categorical 3-level variable, with the highest risk observed in patients undergoing surgery after ≥3 days. After adjusting for age and Charlson index, only the association between surgical delay and treatment failure remained statistically significant (HR: 1.5; 95% CI, 1.1–2.0; p=0.016) (Table 3, Figure 1). Conclusion Delayed surgical intervention for management of NJSA was independently associated with higher risk of treatment failure at 1 year. These findings reinforce current guideline recommendations for timely operative management and further underscore the potential of the DOOR framework to capture clinically meaningful, multidimensional outcomes in NJSA. Disclosures All Authors: No reported disclosures