Citations

Abstract Background Despite effective therapy for methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia with anti-staphylococcal penicillins (ASP; e.g., oxacillin, nafcillin) or cefazolin, persistent bacteremia is associated with poorer clinical outcomes and increased complications. Emerging strategies, such as combination therapy with an ASP or cefazolin and ertapenem, have demonstrated the potential to accelerate microbiologic clearance in persistent MSSA bacteremia. However, despite its increasing utilization in clinical practice, data on the effectiveness of this combination regimen remains limited. We sought to describe the clinical characteristics and outcomes of patients with MSSA bacteremia receiving combination therapy. Methods We performed a single-center, retrospective study of adult patients with MSSA bacteremia who received ASP or cefazolin and ertapenem combination therapy from 2019-2023. Time to blood culture clearance, in-hospital mortality, and 90-day relapse were examined. Results A total of 57 patients were included: median age of 65 years [IQR 53-73] with 75.4% male. MSSA bacteremia complicated by infective endocarditis and cardiac implantable electronic device infection occurred in 35.1% and 12.3%, respectively. The median length-of-stay was 16 days [IQR 12-28], and 57.9% required ICU admission. Forty (70.2%) patients underwent source control interventions such as valve replacement, device extraction or surgical debridement. The median duration of bacteremia prior to combination therapy initiation was 4 days [IQR 3-6]. Blood culture clearance occurred in a median of 1 day. The median duration of combination therapy was 4 days [IQR 3-6]. In-hospital mortality was 15.8%. None of the patients surviving the hospitalization experienced relapsed bacteremia within 90 days. Conclusion This study supports growing evidence that combination therapy may offer benefits in managing persistent MSSA bacteremia, specifically with regards to time to blood culture clearance. Further investigation is warranted to determine optimal timing of combination therapy and if known benefits of combination therapy translate into superior clinical outcomes as compared to monotherapy. Disclosures All Authors: No reported disclosures

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

Abstract Background Clostridium difficile infection (CDI) remains a significant public health concern in the United States, contributing to considerable morbidity and mortality, particularly among hospitalized and elderly populations. This study examines the temporal trends in CDI-related mortality across the United States over recent decades.Figure 1A:Mortality trends among gender; B: Race; C: US Census Region; D: Metropolitan areas. Mortality ratio (Gender): Female = 58.15% Male = 41.85% Mortality ratio (Race): Hispanic = 5.53% Whites = 83.92% Blacks = 8.12% Others = 2.22% Mortality ratio (US Census Region): Northeast = 22.18% Midwest = 24.36% South = 33.13% West = 20.33% Mortality ratio (Metropolitan): Metropolitan areas: 83.78% Non-metropolitan areas: 16.22%Figure 2A:Trends in mortality rates caused by Clostridium Difficile in United States from 1999-2020; and B: from 2021-2023. Top 90th percentile States (crude mortality rate per 100,000 population): Rhode Island: 6.55 Maine: 4.61 Ohio: 4.58 Vermont: 4.21 West Virginia: 4.18 Missouri: 4.11 Bottom 10th percentile States (crude mortality rate per 100,000 population): Georgia: 1.59 Mississippi: 1.49 Louisiana: 1.32 Utah: 1.26 Alaska: 0.96 Hawaii: 0.77 Methods In CDC WONDER analysis, we used total US residents of any age from all 50 states who died due to CDI spanning from the years 1999-2023. The dataset employed demographic attributes, place of death, state-level information, as well as classification into census regions, and the distinction between metropolitan and non-metropolitan localities. The ethnic/racial groups used in our study were classified as Hispanic, Black/African American, White, and others (including American Indian/Alaskan Native, Asian/Pacific Islander) individuals as indicated on the death certificates. US Census regions were categorized into Northeast, Midwest, South, and West based on the definitions provided by the Census Bureau.Figure 3:Place of death among individuals infection with clostridium difficile. Place of Death: Medical Facility - Inpatient: 71.22% Medical Facility - Outpatient or ER: 1.56% Medical Facility - Dead on Arrival: 0.06% Medical Facility - Status unknown: 0.03% Decedent's home: 5.52% Hospice facility: 4.64% Nursing home/long term care: 15.03% Other: 1.72% Place of death unknown: 0.22%Figure 4:Crude mortality rate among States. Crude mortality rate is represented per 100,000 population from the years 1999 to 2023. Results There were a total of 216,311 deaths associated with CDI over the study span. Out of them, 58.1% were females, 41.9% were males, 83.9% were White individuals, 8.12% were Black/African Americans, 5.53% were Hispanics, and 2.22% belonged to other racial groups. About 33% (one-thirds) of the deaths occured in South region followed by 24.4% in Midwest, 22.2% in Northeast and 20.3% in West region. According to NCHS rural-urban scheme classification, 83.8% deaths occured in metropolitan areas and the rest 16.2% in non-metropolitan areas. Conclusion National surveillance data indicate a marked increase in CDI-associated deaths during the early 2000s, largely driven by the emergence of hypervirulent strains and increased antibiotic resistance. However, recent years have shown a gradual decline in mortality rates, attributed to improved infection control practices, antimicrobial stewardship programs, and heightened public awareness. Despite these gains, disparities persist among racial, geographic, and age-specific subgroups, highlighting the need for targeted interventions. This underscores the evolving landscape of CDI mortality and the importance of sustained preventive strategies to further reduce the burden of this infection. Disclosures All Authors: No reported disclosures

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

Abstract Background Despite advancements in vaccination, mortality from Pneumococcal blood stream infections remains high (∼20%). Risk factors include host comorbidities (e.g., immunosuppression, kidney disease, alcohol use, smoking) and certain serotypes. While intensive care unit (ICU) admission and septic shock are associated with poor outcomes, predictors of severe disease remain underexplored. Characteristics of patients with ICU admission within 24 hours of invasive pneumococcal disease diagnosis Epidemiology, clinical characteristics, metastatic complications and management of invasive pneumococcal disease (IPD) Methods We conducted a retrospective review of hospitalized adults with Streptococcus pneumoniae bacteremia between 2013-2023. Clinical comorbidities, laboratory values, vaccination status, microbiologic data, and treatment strategies were collected. Descriptive statistics and univariate logistic regression were used to assess predictors of ICU admission using R Studio v4.4.3 Univariate logistic regression analysis for predictors of ICU admission within 24 hours of diagnosis of streptococcus pneumoniae blood stream infection Rates of streptococcus pneumoniae blood cultures over the years- seasonality trends Results A total of 185 patients were included; the majority were male (60%) with a median age of 64 years (Table 1). Immunocompromising conditions were present in 60%, and only 43% were up to date with pneumococcal vaccination. Metastatic infection was identified in 28% of cases, most commonly meningoencephalitis (74%), musculoskeletal involvement (28%), and endocarditis (12%). ICU admission within 24 hours of presentation was required in 55% of patients (Tables 2 and 3). Predictors of ICU admission included active smoking (OR 2.20), substance use within the past five years (OR 3.45), presence of metastatic foci (OR 2.39), and neurologic complications (OR 6.10). Up-to-date pneumococcal vaccination demonstrated a trend toward a protective effect. 30-day and 90-day mortality rates were 18.9% and 25.4%, respectively. Other predictors of 30-day mortality included smoking history, higher Charlson comorbidity index (CCI), hemodynamic shock at admission, and lab abnormalities such as hypoalbuminemia and elevated liver enzymes. Among the 69 isolates with available serotype data, serogroups 22 and 15 were most frequently identified. Conclusion Pneumococcal bloodstream infections are associated with substantial mortality, particularly among patients requiring ICU admission. Smoking, recent substance use, and the presence of metastatic complications were significantly associated with severe disease and ICU admission. Up-to-date pneumococcal vaccination demonstrated a protective effect. Disclosures All Authors: No reported disclosures

Abstract Background Parkinson's disease (PD) represents a growing global health challenge, with prevalence doubling from 2.5 million cases in 1990 to 6.1 million in 2016, and projections suggesting it will exceed 12 million by 2040. This exponential growth has been termed the "Parkinson's pandemic." China and the United States, which together account for nearly half of the global PD population, have developed markedly different approaches to end-of-life (EOL) care, shaped by their distinct healthcare systems and cultural contexts. Understanding these differences is crucial for developing effective global strategies. This systematic review and meta-analysis comprehensively compares advanced-stage PD care between these two nations to quantify disparities and inform evidence-based policy interventions. Methods We conducted a rigorous systematic review following PRISMA 2020 guidelines, searching six databases (PubMed, Embase, Scopus, Web of Science, CNKI, Wanfang) from January 2015 to October 2025. The timeframe was selected to capture contemporary care patterns following major healthcare reforms in both countries (Affordable Care Act implementation in the US; Healthy China 2030 initiative). Inclusion criteria encompassed peer-reviewed studies reporting on advanced PD (Hoehn-Yahr stage ≥ 3) with outcome measures including survival, quality of life (QoL), palliative care access, caregiver burden, rehabilitation utilization, or healthcare costs. The sample size threshold (n ≥ 100) balanced statistical power with inclusivity. Two independent reviewers screened 3,847 records with excellent agreement (Cohen's κ = 0.82–0.89). Quality assessment employed the Newcastle-Ottawa Scale (NOS ≥ 8 indicating high quality) and ROBINS-I for observational studies, with GRADE criteria determining evidence certainty. Meta-analyses utilized random-effects models with comprehensive heterogeneity assessment (I² statistics, meta-regression) and publication bias evaluation (Egger's test, trim-and-fill analysis). Sensitivity analyses included high-quality studies only and examined the influence of large database studies. Results Our analysis of 42 high-quality studies encompassing over 125,000 patients revealed profound and systematic cross-national disparities across multiple domains. In terms of care access, US patients demonstrated significantly higher hospice enrollment rates (28–35% vs. <1% in China, p < 0.001; HIGH certainty evidence) and greater access to specialized neuropalliative programs (15% of US centers vs. <1% in China). These differences translated into measurable quality of life disparities, with Chinese patients scoring 17.6 points worse on the PDQ-39 scale (95% CI 14.2–21.0; MODERATE certainty, I²=68%), a difference exceeding the minimal clinically important difference nearly four-fold. The burden on families showed equally striking patterns: Chinese families provided 94% of EOL care compared to 61% in the US, resulting in significantly higher caregiver depression rates (47% vs. 32%, OR = 1.89, 95% CI 1.45–2.47) and burden scores (Zarit difference: 10.2 points, 95% CI 7.8–12.6). Access to interventions revealed additional gaps, with only 9.2% of Chinese patients receiving physical therapy versus 14.4% in the US (OR = 0.61, 95% CI 0.49–0.76), and a 5.25-fold disparity in deep brain stimulation access (4.2% vs. 0.8%). Economic analysis demonstrated substantial out-of-pocket burden differences: Chinese families paid 58% of total costs ($4,200 annually) versus 12% for US families ($2,800). Meta-regression identified healthcare system characteristics as the primary driver of these disparities (R²=0.42, p < 0.001). Conclusions This comprehensive analysis reveals that systematic differences in healthcare infrastructure, insurance coverage, and cultural care models produce markedly divergent EOL experiences for PD patients in China versus the United States. These findings have immediate policy implications. For China, we recommend: (1) establishing pilot neuropalliative programs in tertiary centers with phased national expansion; (2) developing caregiver support infrastructure including respite care and training programs; (3) leveraging telemedicine platforms to address urban-rural disparities. For the United States, priorities include: (1) addressing racial disparities in rehabilitation access through culturally competent outreach; (2) expanding Medicare coverage for maintenance therapy; (3) earlier integration of neuropalliative care. Implementation science research is urgently needed to test culturally adapted interventions. As global PD prevalence accelerates, lessons from this bilateral comparison provide a framework for other nations confronting similar challenges in neurological care delivery.

Abstract Background Spinal cord injury causes motor, sensory, and autonomic impairments. Transcutaneous spinal cord stimulation (tSCS) has shown potential to improve autonomic regulation, particularly cardiovascular and bladder control. Heart rate variability (HRV) serves as a non-invasive marker of autonomic balance, reflecting modulation of cardiac sympathetic and parasympathetic activity. The purpose of this study was to evaluate the effect of combined tSCS and physical therapy (tSCS + PT) on HRV and autonomic function metrics in chronic spinal cord injury. Methods. Eight participants (2 with tetraplegia, 6 with paraplegia) received tSCS at 30 Hz targeting T11–L1 or C5–T1, depending on injury level. Each underwent two tSCS + PT sessions per week for 12 weeks, followed by a 4-week washout period. Autonomic assessments included the Autonomic Standard Evaluation Form (ASAF), Neurologic Bladder Symptoms Score (NBSS), blood pressure, heart rate, SpO2%, and core temperature. Electrocardiograms were recorded pre- and post-tSCS + PT at baseline, 12, and 16 weeks. Results. Baseline effects of tSCS + PT revealed increased time-domain HRV parameters, suggesting enhanced cardiac parasympathetic activation (PSA). After 12 weeks, these parameters decreased, suggesting reduced cardiac PSA and enhanced sympathetic activation (SA). Similar results were found with frequency-domain parameters. Time-and frequency-domain parameters tended to return toward baseline after the 4-week therapy suspension. Two commonly reported HRV parameters, SDNN and RMSSD, showed large effects (g = 1.64, CI 95% [0.30, 2.98], and g = 1.23, CI 95% [0.11, 2.42], respectively) at 12 weeks when comparing pre- vs. post-tSCS + PT. Moderate, subject-related differences across evaluations were found in ASAF and NBSS (p > 0.05). Physiological metrics across time points did not show statistically significant differences (p > 0.05). Physiological metrics across time points did not show statistically significant differences (p > 0.05). Conclusions Combined tSCS + PT elicited improvements in autonomic clinical measures, without statistically significant changes in time-domain or frequency-domain HRV parameters. Nonetheless, trends and size effect in SDNN and RMSSD suggested that tSCS + PT induced midterm SA and a transient PSA immediately post-tSCS + PT. The partial recovery of HRV after tSCS withdrawal indicates that the observed autonomic changes were therapy-related.

Abstract Background Anxiety disorders (ANX) affect 30–60% of individuals with bipolar disorder (BD), yet limited research has systematically examined clinical characteristics and treatment patterns in this comorbid population. This study investigated demographic, clinical, and pharmacotherapeutic differences between individuals with BD with and without comorbid ANX. Methods Cross-sectional data from 2,225 adults with BD enrolled in the Mayo Clinic Bipolar Disorder Biobank were analyzed. Participants were assessed for comorbid ANX, demographics, clinical characteristics, medication use, and treatment response using the Alda-A scale. Results Overall, 61% (n = 1,366) had comorbid ANX. Individuals with BD + ANX were younger (40.4 vs. 43.6 years, p < 0.001), more likely female (66.6% vs. 54.8%, p < 0.001), and exhibited higher rates of rapid cycling (64.2% vs. 45.2%, p < 0.001), suicide attempts (40.4% vs. 24.8%, p < 0.001), substance use disorders (63.5% vs. 54.8%, p < 0.001), and somatic comorbidities (MCIRS: 6.68 vs. 5.42, p < 0.001). Pharmacotherapeutically, BD + ANX individuals were less likely to receive lithium (37.1% vs. 47.8%, p = 0.005) and valproic acid (21.7% vs. 29.6%, p = 0.047), but more likely to receive antidepressants (53.8% vs. 39.5%, p < 0.001), benzodiazepines (39.9% vs. 26.6%, p < 0.001), and gabapentinoids (8.5% vs. 4.5%, p < 0.001). Notably, 17.3% of BD + ANX individuals received antidepressants without mood stabilizer coverage. Treatment response (Alda-A) scores were significantly lower in BD + ANX for lithium (4.91 vs. 6.05, p < 0.001), mood-stabilizing anticonvulsants (5.09 vs. 6.22, p < 0.001), and second-generation antipsychotics (4.67 vs. 5.73, p < 0.001). Similar patterns were observed in both BD-I and BD-II subtypes. Conclusions Individuals with BD + ANX represent a more severely affected subgroup with distinct prescribing patterns favoring antidepressants over mood stabilizers and attenuated mood stabilizers response. These findings highlight the need for anxiety-informed treatment algorithms recognizing anxiety comorbidity as a negative prognostic factor.

BACKGROUND High-flow nasal cannula (HFNC) therapy is widely used in infants hospitalized with moderate-to-severe bronchiolitis. Although bronchiolitis severity has been consistently associated with later asthma, it remains unclear whether HFNC contributes additional risk or instead represents a marker of severe illness. We examined the relationship between HFNC use during bronchiolitis hospitalization and the subsequent hazard of asthma diagnosis in early childhood. METHODS We conducted a retrospective cohort study of 4736 children aged younger than 2 years hospitalized with bronchiolitis from 2015 to 2023 across 2 tertiary children’s hospitals. Children were stratified by HFNC exposure. Cox proportional hazards models evaluated the association between HFNC use and subsequent asthma diagnosis. Secondary analyses assessed HFNC duration and frequency. RESULTS Forty-three percent of children received HFNC. Asthma was subsequently diagnosed in 37% of HFNC-treated children and 22% of non-HFNC children (P &lt; .001). After adjustment for demographic and clinical variables, HFNC use was associated with a 40% increased hazard of subsequent asthma diagnosis (hazard ratio, 1.40; 95% CI, 1.24–1.57; P &lt; .001). No dose-response pattern was observed by HFNC duration or frequency. CONCLUSION HFNC use was associated with an increased hazard of subsequent diagnosis of asthma in childhood, likely reflecting underlying disease severity rather than a treatment-related effect. Prospective studies are needed to differentiate severity-related risk from treatment-associated factors to optimize respiratory support strategies for infants with bronchiolitis.

Significance: Immune checkpoint inhibitors (ICIs) have transformed cancer therapy by reactivating antitumor immunity and improving outcomes across multiple malignancies. Yet, clinical observations and preclinical studies suggest that ICIs may increase long-term cardiovascular disease risk, including hypertension, atherosclerosis, and thrombosis. The underlying mechanisms remain incompletely defined, highlighting the need for focused investigation into the vascular consequences of immune activation. Recent Advances: ICI-induced immune activation disrupts vascular and immune homeostasis through persistent production of reactive oxygen species (ROS), mitochondrial dysfunction, and accumulation of cell-free DNA (cfDNA). Sustained T-cell activation enhances ROS generation, driving DNA damage and senescence in both endothelial and immune cells. ICIs may also promote endothelial-to-mesenchymal transition (EndoMT) through chronic oxidative and inflammatory signaling, contributing to fibrosis, vascular stiffness, and chronic inflammation. Transforming growth factor-beta, although immunosuppressive in many contexts, can drive profibrotic and EndoMT programs within the vasculature. Other cytokines and regulators, including interleukin-17 and regulator of calcineurin 1, have been implicated in vascular remodeling, atherosclerosis, and hypertension. Critical Issues: The relative roles of ROS, mitochondrial dysfunction, cfDNA-driven inflammation, and EndoMT in ICI-associated vascular senescence remain unclear. While inflammation-induced vascular damage is well-recognized, direct ICI-specific mechanisms require stronger evidence. How senescent endothelial and immune cells influence therapy resistance and remodeling of the tumor microenvironment also remains to be defined. Future Directions: Mitochondrial and cytosolic ROS sources—arising from electron leakage during oxidative phosphorylation and NADPH oxidases activity—shape immune signaling and sustain T-cell activation during checkpoint blockade. The DNA damage response kinases ataxia-telangiectasia mutated and ATM- and Rad3-related, activated by oxidative and replicative stress, engage p53-dependent senescence pathways in endothelial and immune cells. Future studies should evaluate biomarkers such as cfDNA and thrombospondin-1 and explore senescence-targeting or redox-modulating interventions that may alleviate cardiovascular toxicity without diminishing antitumor efficacy. This review outlines mechanistic pathways linking ICIs to vascular dysfunction and senescence, integrating preclinical data with emerging clinical insights. It distinguishes established processes from ICI-specific hypotheses and identifies key gaps requiring clinical validation. Antioxid. Redox Signal. 00, 000–000.