Air pollution and serious bleeding events in high-risk older adults.

IMPORTANCE: Despite biological plausibility, very few epidemiologic studies have investigated the risks of clinically significant bleeding events due to particulate air pollution. OBJECTIVE: To measure the independent and synergistic effects of PM2.5 exposure and anticoagulant use on serious bleeding events. DESIGN: Retrospective cohort study (2008-2016). SETTING: Nationwide Medicare population. PARTICIPANTS: A 50% random sample of Medicare Part D-eligible Fee-for-Service beneficiaries at high risk for cardiovascular and thromboembolic events. EXPOSURES: Fine particulate matter (PM2.5) and anticoagulant drugs (apixaban, dabigatran, edoxaban, rivaroxaban, or warfarin). MAIN OUTCOMES AND MEASURES: The outcomes were acute hospitalizations for gastrointestinal bleeding, intracranial bleeding, or epistaxis. Hazard ratios and 95% CIs for PM2.5 exposure were estimated by fitting inverse probability weighted marginal structural Cox proportional hazards models. The relative excess risk due to interaction was used to assess additive-scale interaction between PM2.5 exposure and anticoagulant use. RESULTS: The study cohort included 1.86 million high-risk older adults (mean age 77, 60% male, 87% White, 8% Black, 30% anticoagulant users, mean PM2.5 exposure 8.81 µg/m3). A 10 µg/m3 increase in PM2.5 was associated with a 48% (95% CI: 45%-52%), 58% (95% CI: 49%-68%) and 55% (95% CI: 37%-76%) increased risk of gastrointestinal bleeding, intracranial bleeding, and epistaxis, respectively. Significant additive interaction between PM2.5 exposure and anticoagulant use was observed for gastrointestinal and intracranial bleeding. CONCLUSIONS: Among older adults at high risk for cardiovascular and thromboembolic events, increasing PM2.5 exposure was significantly associated with increased risk of gastrointestinal bleeding, intracranial bleeding, and epistaxis. In addition, PM2.5 exposure and anticoagulant use may act together to increase risks of severe gastrointestinal and intracranial bleeding. Thus, clinicians may recommend that high-risk individuals limit their outdoor air pollution exposure during periods of increased PM2.5 concentrations. Our findings may inform environmental policies to protect the health of vulnerable populations.

Ambient heat exposure patterns and emergency department visits and hospitalizations among medicare beneficiaries 2008-2019.

OBJECTIVE: To assess the association between ambient heat and all-cause and cause-specific emergency department (ED) visits and acute hospitalizations among Medicare beneficiaries in the conterminous United States. DESIGN: Retrospective cohort study. SETTING: Conterminous US from 2008 and 2019. PARTICIPANTS: 2% random sample of all Medicare fee-for-service beneficiaries eligible for Parts A, B, and D. MAIN OUTCOME MEASURES: All-cause and cause-specific (cardiovascular, renal, and heat-related) ED visits and unplanned hospitalizations were identified using primary ICD-9 or ICD-10 diagnosis codes. We measured the association between ambient temperature - defined as daily mean temperature percentile of summer (June through September) - and the outcomes. Hazard ratios and their associated 95% confidence intervals were estimated using multivariable Cox proportional hazards regression, adjusting for individual level demographics, comorbidities, healthcare utilization factors and zip-code level social factors. RESULTS: Among 809,636 Medicare beneficiaries (58% female, 81% non-Hispanic White, 24% <65), older beneficiaries (aged ≥65) exposed to >95th percentile temperature had a 64% elevated adjusted risk of heat-related ED visits (HR [95% CI], 1.64 [1.46,1.85]) and a 4% higher risk of all-cause acute hospitalization (1.04 [1.01,1.06]) relative to <25th temperature percentile. Younger beneficiaries (aged <65) showed increased risk of heat-related ED visits (2.69 [2.23,3.23]) and all-cause ED visits (1.03 [1.01,1.05]). The associations with heat related events were stronger in males and individuals dually eligible for Medicare and Medicaid. No significant differences were observed by climatic region. We observed no significant relationship between temperature percentile and risk of CV-related ED visits or renal-related ED visits. CONCLUSIONS: Among Medicare beneficiaries from 2008 to 2019, exposure to daily mean temperature ≥ 95th percentile was associated with increased risk of heat-related ED visits, with stronger associations seen among beneficiaries <65, males, and patients with low socioeconomic position. Further longitudinal studies are needed to understand the impact of heat duration, intensity, and frequency on cause-specific hospitalization outcomes.

National Trends in Anticoagulation Therapy for COVID-19 Hospitalized Adults in the United States: Analyses of the National COVID Cohort Collaborative.

BACKGROUND: Anticoagulation (AC) utilization patterns and their predictors among hospitalized coronavirus disease 2019 (COVID-19) patients have not been well described. METHODS: Using the National COVID Cohort Collaborative, we conducted a retrospective cohort study (2020-2022) to assess AC use patterns and identify factors associated with therapeutic AC employing modified Poisson regression. RESULTS: Among 162 842 hospitalized COVID-19 patients, 64% received AC and 24% received therapeutic AC. Therapeutic AC use declined from 32% in 2020 to 12% in 2022, especially after December 2021. Therapeutic AC predictors included age (relative risk [RR], 1.02; 95% confidence interval [CI], 1.02-1.02 per year), male (RR, 1.29; 95% CI, 1.27-1.32), non-Hispanic black (RR, 1.16; 95% CI, 1.13-1.18), obesity (RR, 1.48; 95% CI, 1.43-1.52), increased length of stay (RR, 1.01; 95% CI, 1.01-1.01 per day), and invasive ventilation (RR, 1.64; 95% CI, 1.59-1.69). Vaccination (RR, 0.88; 95% CI, 84-.92) and higher Charlson Comorbidity Index (CCI) (RR, 0.98; 95% CI, .97-.98) were associated with lower therapeutic AC. CONCLUSIONS: Overall, two-thirds of hospitalized COVID-19 patients received any AC and a quarter received therapeutic dosing. Therapeutic AC declined after introduction of the Omicron variant. Predictors of therapeutic AC included demographics, obesity, length of stay, invasive ventilation, CCI, and vaccination, suggesting AC decisions driven by clinical factors including COVID-19 severity, bleeding risks, and comorbidities.

Air Pollution and Cardiovascular and Thromboembolic Events in Older Adults With High-Risk Conditions.

Little epidemiologic research has focused on pollution-related risks in medically vulnerable or marginalized groups. Using a nationwide 50% random sample of 2008-2016 Medicare Part D-eligible fee-for-service participants in the United States, we identified a cohort with high-risk conditions for cardiovascular and thromboembolic events (CTEs) and linked individuals with seasonal average zip-code-level concentrations of fine particulate matter (particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5)). We assessed the relationship between seasonal PM2.5 exposure and hospitalization for each of 7 CTE-related causes using history-adjusted marginal structural models with adjustment for individual demographic and neighborhood socioeconomic variables, as well as baseline comorbidity, health behaviors, and health-service measures. We examined effect modification across geographically and demographically defined subgroups. The cohort included 1,934,453 individuals with high-risk conditions (mean age = 77 years; 60% female, 87% White). A 1-µg/m3 increase in PM2.5 exposure was significantly associated with increased risk of 6 out of 7 types of CTE hospitalization. Strong increases were observed for transient ischemic attack (hazard ratio (HR) = 1.039, 95% confidence interval (CI): 1.034, 1.044), venous thromboembolism (HR = 1.031, 95% CI: 1.027, 1.035), and heart failure (HR = 1.019, 95% CI: 1.017, 1.020). Asian Americans were found to be particularly susceptible to thromboembolic effects of PM2.5 (venous thromboembolism: HR = 1.063, 95% CI: 1.021, 1.106), while Native Americans were most vulnerable to cerebrovascular effects (transient ischemic attack: HR = 1.093, 95% CI: 1.030, 1.161).

Hypertension, diabetes, and corresponding annual clinical testing utilization: Comparison between Asian Indians and other races/ethnicities.

Asian Indians are at increased risk of developing cardiometabolic diseases. We sought to determine differences between Asian Indians and other races/ethnicities in hypertension and diabetes prevalence and associated annual blood pressure (BP) and fasting blood glucose (FBG) testing. A total of 257,652 adults ≥18 years from the 2011-2018 U.S. National Health Interview Surveys (NHIS) were included. BP and FBG testing in the past 12 months was defined dichotomously (yes/not yes). Racial/ethnic groups included non-Hispanic White (NHW), non-Hispanic Black (NHB), Asian Indian, Other Asians, and Hispanic/Multiracial. We used logistic regression, adjusting for covariates and the survey design. Analyses were completed from 08/2020-06/2021. Asian Indians (N = 3049) had 21% and 99% higher odds of hypertension and diabetes, respectively, than NHWs (aOR [95% CI]; hypertension: 1.21[1.04,1.40], diabetes: 1.99[1.64,2.41]). Accordingly, Asian Indians without diabetes had significantly higher odds of FBG screening than NHWs (Asian Indian: 1.41[1.25,1.59], NHB: 0.99 [0.95,1.04], Other Asian: 1.07[0.98, 1.18], Hispanic: 1.13[1.07,1.20]). Asian Indians without hypertension had a 14% insignificant increase in BP testing compared to NHWs (1.14[0.97,1.33]). Predictors of testing in Asian Indians included older age, doctor's visit, graduate-level education, insurance coverage, and history of hypertension or diabetes. NHBs with diabetes and Hispanics with hypertension had lower odds of FBG testing (0.75[0.66,0.84]) and BP testing (0.85[0.79,0.92]), respectively, than NHWs. Asian Indians have higher odds of diabetes and hypertension than NHWs and higher, but relatively lower, odds of FBG and BP testing. Increasing routine BP and FBG testing in Asian Indians in younger adults may allow for earlier detection of high-risk individuals.

Important considerations when assessing the effect of essential fatty acids on cognitive performance.

Over the past decade, there have been many studies determining the effect of dietary ω-3 and ω-6 fatty acids intake on cognitive performance; however, they have largely been inconsistent in their conclusions. In this letter, we provide context to the article by Dong et al., titled "Association of dietary ω-3 and ω-6 fatty acids intake with cognitive performance in older adults: National Health and nutrition examination Survey (NHANES) 2011-2014" and provide methodological considerations with regards to covariate measurement and inclusion that can be generalized to future cross-sectional studies. In particular, delineating 1) the type and source of fatty acid, in context of an individual's overall dietary patterns, 2) sociobehavioral risk factors and physical & mental comorbidities, 3) and daily cognitive activity are important to adequately control for covariates.

Increased serum selenium levels are associated with reduced risk of advanced liver fibrosis and all-cause mortality in NAFLD patients: National Health and Nutrition Examination Survey (NHANES) III.

INTRODUCTION AND OBJECTIVES: Selenium supplementation has been shown to have therapeutic value in chronic liver disease. We aimed to investigate the association between serum selenium, severity of liver fibrosis, and mortality in patients with Nonalcoholic Fatty Liver Disease (NAFLD). PATIENTS OR MATERIAL AND METHODS: A total of 33,944 patients were identified from the Third National Health and Nutrition Examination Survey. NAFLD was diagnosed by hepatic ultrasound after the exclusion of other forms of liver diseases. The severity of liver fibrosis was determined by NAFLD Fibrosis Score >0.676. Multivariate logistic regression analysis was used to investigate the relationship between serum selenium level and liver fibrosis. Association between serum selenium and all-cause mortality in NAFLD patients was also evaluated. RESULTS: Multivariate logistic regression analysis demonstrated odds ratio of advanced liver fibrosis (NFS > 0.676) was significantly reduced with increasing serum selenium levels; OR 0.55, [95% CI 0.32-0.94] in the highest selenium quartile. On stratification analysis, the following populations had a significantly reduced risk of advanced liver fibrosis: non-Hispanic white = OR 0.41 [0.24,0.68]; female = OR 0.32 [0.15-0.66] and age >47 = OR 0.47 [0.28-0.79]. The relationship was significant regardless of BMI as noted by BMI ≤ 30 Kg/m2= OR 0.42 [0.19-0.91] and BMI > 30 Kg/m2=OR 0.52 [0.28-0.97]. Hazard ratio for all-cause mortality was HR 0.72 [0.56-0.95]. CONCLUSIONS: The risk of advanced liver fibrosis is inversely associated with serum selenium levels, particularly in older patients, Caucasians, and females. All-cause mortality decreased with increased selenium levels. Selenium may play a role in the prevention of liver fibrosis in NAFLD.

Blood lead level is associated with advanced liver fibrosis in patients with non-alcoholic fatty liver disease: A nationwide survey (NHANES 2011-2016).

INTRODUCTION AND OBJECTIVES: Non-Alcoholic Fatty Liver Disease (NAFLD) is linked to obesity and metabolic syndrome, but increasing evidence also implicates environmental toxins. In this study, we aim to show that in elevated blood Lead levels in NAFLD patients result in worsening liver fibrosis. MATERIALS AND METHODS: 30,172 patients from NHANES 2011-2016 met inclusion criteria. 2499 patients ages 20-74 were identified with NAFLD as determined by the Fatty Liver Index score, and 425 with advanced liver fibrosis were identified using the NAFLD Fibrosis Score. Simple linear regression, Student's T-test, and Rao-Scott Chi-Square test was used for continuous and categorical variables. Multivariate regression analysis was used to adjust for confounders to determine odds of Advanced Fibrosis. RESULTS: Increased serum Lead level was independently associated with increased risk of Advanced Fibrosis (OR 5.93, 95% CI 2.88-12.24) in the highest Lead quartile (Q4). In subgroup analysis stratified by BMI, a significant association between advanced liver fibrosis and blood Lead levels was consistently present, Q4 (OR 5.78, 95% CI 0.97-33.63) and Q4 (OR 6.04, 95% CI 2.92-12.48) in BMI <30 and >30, respectively. Increased Lead exposure was also evident in patients who were older, less educated, male, and drank alcohol and smoked tobacco. CONCLUSIONS: Our findings show that advanced liver fibrosis is up to six times more likely in NAFLD patients with increased Lead exposure.

Inverse association between total bilirubin and type 2 diabetes in U.S. South Asian males but not females.

AIMS: United States South Asians constitute a fast-growing ethnic group with high prevalence of type 2 diabetes (T2D) despite lower mean BMI and other traditional risk factors compared to other races/ethnicities. Bilirubin has gained attention as a potential antioxidant, cardio-protective marker. Hence we sought to determine whether total bilirubin was associated with prevalent and incident T2D in U.S. South Asians. METHODS: We conducted a cross-sectional and prospective analysis of the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study. Total bilirubin was categorized into gender-specific quartiles (Men: <0.6, 0.6, 0.7-0.8, >0.8; Women: <0.5, 0.5, 0.6, >0.6 mg/dl). We estimated odds of type 2 diabetes as well as other cardiovascular (CV) risk factors using multivariable logistic regression. RESULTS: Among a total 1,149 participants (48% female, mean [SD] age of 57 [9] years), 38% had metabolic syndrome and 24% had T2D. Men and women in the lowest bilirubin quartile had 0.55% and 0.17% higher HbA1c than the highest quartile. Men, but not women, in the lowest bilirubin quartile had higher odds of T2D compared to the highest quartile (aOR [95% CI]; Men: 3.00 [1.72,5.23], Women: 1.15 [0.57,2.31]). There was no association between bilirubin and other CV risk factors. CONCLUSION: Total bilirubin was inversely associated with T2D in SA men but not women. Longitudinal studies are needed to understand temporality of association.

Is it time to consider a "time-out" before primary prevention implantable cardioverter-defibrillator in currently or recently hospitalized older patients with heart failure?

BACKGROUND: Trajectories of mortality after primary implantable cardioverter-defibrillator (ICD) placement for older patients with heart failure during or soon after acute hospitalization have not been assessed. OBJECTIVE: The purpose of this study was to compare trajectories of mortality after primary ICD placement during or soon after acute cardiac or noncardiac hospitalization. METHODS: We identified older patients with heart failure undergoing primary ICD placement using 20% Medicare data (2008-2018). Placement settings were as follows: (1) "current-H"-during current hospitalization, (2) "recent-H"-within 90 days of hospitalization, or (3) "chronic stable." Hospitalization was categorized as cardiac vs noncardiac. Interval mortality rates and hazard ratios (HRs) using Cox regression were estimated at 0-30, 31-90, and 91-365 days after ICD placement. RESULTS: Of the 61,710 patients (mean age 76 years; 35% female; 85% white), 19%, 25%, and 56% had ICDs in "current-H," "recent-H," and "chronic stable" settings. Mortality rates (per 100 person-years) were highest during 0-30 days, with 38 (34-42) and 22 (19-24) for "current-H" and "recent-H," which declined to 21 (20-22) and 16 (15-17) during 91-365 days, respectively. Compared to "chronic stable," HRs were highest during 0-30 days post-ICD placement (5.5 [4.5-6.8] for "current-H" and 3.4 [2.8-4.2] for "recent-H") and decreased during 91-365 days ("current-H": 2.0 [1.8-2.1] for "current-H" and 1.6 [1.5-1.7] for "recent-H"). HR pattens were similar for cardiac and noncardiac hospitalizations. CONCLUSION: Primary ICD placement during or soon after hospitalization for any reason was associated with worse mortality with diminishing risks after 90 days. Hospitalization likely identifies a sicker population in whom early mortality with or without ICD may be higher. Our results support careful consideration regarding ICD placement during the 90 days after hospitalization.

Ambient Heat and Risk of Serious Hypoglycemia in Older Adults With Diabetes Using Insulin in the U.S. and Taiwan: A Cross-National Case-Crossover Study.

OBJECTIVE: To measure the association between ambient heat and hypoglycemia-related emergency department visit or hospitalization in insulin users. RESEARCH DESIGN AND METHODS: We identified cases of serious hypoglycemia among adults using insulin aged ≥65 in the U.S. (via Medicare Part A/B/D-eligible beneficiaries) and Taiwan (via National Health Insurance Database) from June to September, 2016-2019. We then estimated odds of hypoglycemia by heat index (HI) percentile categories using conditional logistic regression with a time-stratified case-crossover design. RESULTS: Among ∼2 million insulin users in the U.S. (32,461 hypoglycemia case subjects), odds ratios of hypoglycemia for HI >99th, 95-98th, 85-94th, and 75-84th percentiles compared with the 25-74th percentile were 1.38 (95% CI, 1.28-1.48), 1.14 (1.08-1.20), 1.12 (1.08-1.17), and 1.09 (1.04-1.13) respectively. Overall patterns of associations were similar for insulin users in the Taiwan sample (∼283,000 insulin users, 10,162 hypoglycemia case subjects). CONCLUSIONS: In two national samples of older insulin users, higher ambient temperature was associated with increased hypoglycemia risk.

Body mass index and all-cause mortality in a 21st century U.S. population: A National Health Interview Survey analysis.

INTRODUCTION: Much of the data on BMI-mortality associations stem from 20th century U.S. cohorts. The purpose of this study was to determine the association between BMI and mortality in a contemporary, nationally representative, 21st century, U.S. adult population. METHODS: This was a retrospective cohort study of U.S. adults from the 1999-2018 National Health Interview Study (NHIS), linked to the National Death Index (NDI) through December 31st, 2019. BMI was calculated using self-reported height & weight and categorized into 9 groups. We estimated risk of all-cause mortality using multivariable Cox proportional hazards regression, adjusting for covariates, accounting for the survey design, and performing subgroup analyses to reduce analytic bias. RESULTS: The study sample included 554,332 adults (mean age 46 years [SD 15], 50% female, 69% non-Hispanic White). Over a median follow-up of 9 years (IQR 5-14) and maximum follow-up of 20 years, there were 75,807 deaths. The risk of all-cause mortality was similar across a wide range of BMI categories: compared to BMI of 22.5-24.9 kg/m2, the adjusted HR was 0.95 [95% CI 0.92, 0.98] for BMI of 25.0-27.4 and 0.93 [0.90, 0.96] for BMI of 27.5-29.9. These results persisted after restriction to healthy never-smokers and exclusion of subjects who died within the first two years of follow-up. A 21-108% increased mortality risk was seen for BMI ≥30. Older adults showed no significant increase in mortality between BMI of 22.5 and 34.9, while in younger adults this lack of increase was limited to the BMI range of 22.5 to 27.4. CONCLUSION: The risk of all-cause mortality was elevated by 21-108% among participants with BMI ≥30. BMI may not necessarily increase mortality independently of other risk factors in adults, especially older adults, with overweight BMI. Further studies incorporating weight history, body composition, and morbidity outcomes are needed to fully characterize BMI-mortality associations.

Retrospective cohort study investigating synergism of air pollution and corticosteroid exposure in promoting cardiovascular and thromboembolic events in older adults.

OBJECTIVE: To evaluate the synergistic effects created by fine particulate matter (PM2.5) and corticosteroid use on hospitalisation and mortality in older adults at high risk for cardiovascular thromboembolic events (CTEs). DESIGN AND SETTING: A retrospective cohort study using a US nationwide administrative healthcare claims database. PARTICIPANTS: A 50% random sample of participants with high-risk conditions for CTE from the 2008-2016 Medicare Fee-for-Service population. EXPOSURES: Corticosteroid therapy and seasonal-average PM2.5. MAIN OUTCOME MEASURES: Incidences of myocardial infarction or acute coronary syndrome (MI/ACS), ischaemic stroke or transient ischaemic attack, heart failure (HF), venous thromboembolism, atrial fibrillation and all-cause mortality. We assessed additive interactions between PM2.5 and corticosteroids using estimates of the relative excess risk due to interaction (RERI) obtained using marginal structural models for causal inference. RESULTS: Among the 1 936 786 individuals in the high CTE risk cohort (mean age 76.8, 40.0% male, 87.4% white), the mean PM2.5 exposure level was 8.3±2.4 µg/m3 and 37.7% had at least one prescription for a systemic corticosteroid during follow-up. For all outcomes, we observed increases in risk associated with corticosteroid use and with increasing PM2.5 exposure. PM2.5 demonstrated a non-linear relationship with some outcomes. We also observed evidence of an interaction existing between corticosteroid use and PM2.5 for some CTEs. For an increase in PM2.5 from 8 µg/m3 to 12 µg/m3 (a policy-relevant change), the RERI of corticosteroid use and PM2.5 was significant for HF (15.6%, 95% CI 4.0%, 27.3%). Increasing PM2.5 from 5 µg/m3 to 10 µg/m3 yielded significant RERIs for incidences of HF (32.4; 95% CI 14.9%, 49.9%) and MI/ACSs (29.8%; 95% CI 5.5%, 54.0%). CONCLUSION: PM2.5 and systemic corticosteroid use were independently associated with increases in CTE hospitalisations. We also found evidence of significant additive interactions between the two exposures for HF and MI/ACSs suggesting synergy between these two exposures.

Influence of social deprivation index on in-hospital outcomes of COVID-19.

While it is known that social deprivation index (SDI) plays an important role on risk for acquiring Coronavirus Disease 2019 (COVID-19), the impact of SDI on in-hospital outcomes such as intubation and mortality are less well-characterized. We analyzed electronic health record data of adults hospitalized with confirmed COVID-19 between March 1, 2020 and February 8, 2021 from the INSIGHT Clinical Research Network (CRN). To compute the SDI (exposure variable), we linked clinical data using patient's residential zip-code with social data at zip-code tabulation area. SDI is a composite of seven socioeconomic characteristics determinants at the zip-code level. For this analysis, we categorized SDI into quintiles. The two outcomes of interest were in-hospital intubation and mortality. For each outcome, we examined logistic regression and random forests to determine incremental value of SDI in predicting outcomes. We studied 30,016 included COVID-19 patients. In a logistic regression model for intubation, a model including demographics, comorbidity, and vitals had an Area under the receiver operating characteristic curve (AUROC) = 0.73 (95% CI 0.70-0.75); the addition of SDI did not improve prediction [AUROC = 0.73 (95% CI 0.71-0.75)]. In a logistic regression model for in-hospital mortality, demographics, comorbidity, and vitals had an AUROC = 0.80 (95% CI 0.79-0.82); the addition of SDI in Model 2 did not improve prediction [AUROC = 0.81 (95% CI 0.79-0.82)]. Random forests revealed similar findings. SDI did not provide incremental improvement in predicting in-hospital intubation or mortality. SDI plays an important role on who acquires COVID-19 and its severity; but once hospitalized, SDI appears less important.

Racial differences in setting of implantable cardioverter-defibrillator placement in older adults with heart failure and association with disparate post-implant outcomes.

Background: Implantable cardioverter-defibrillator (ICD) placement in heart failure (HF) patients during or early after (≤90 days) unplanned cardiovascular hospitalizations has been associated with poor outcomes. Racial and ethnic differences in this "peri-hospitalization" ICD placement have not been well described. Methods: Using a 20% random sample of Medicare beneficiaries, we identified older (≥66 years) patients with HF who underwent ICD placement for primary prevention from 2008 to 2018. We investigated racial and ethnic differences in frequency of peri-hospitalization ICD placement using modified Poisson regression. We utilized Kaplan-Meier analyses and Cox regression to investigate the association of peri-hospitalization ICD placement with differences in all-cause mortality and hospitalization (HF, cardiovascular and all-cause) within and between race and ethnicity groups for up to 5-year follow-up. Results: Among the 61,710 beneficiaries receiving ICDs (35% female, 82% White, 10% Black, 6% Hispanic), 44% were implanted peri-hospitalization. Black [adjusted rate ratio (RR) 95% Confidence Interval (95% CI): 1.16 (1.12, 1.20)] and Hispanic [RR (95% CI): 1.10 (1.06, 1.14)] beneficiaries were more likely than White beneficiaries to have ICD placement peri-hospitalization. Peri-hospitalization ICD placement was associated with an at least 1.5× increased risk of death, 1.5× increased risk of re-hospitalization and 1.7× increased risk of HF hospitalization during 3-year follow-up in fully adjusted models. Although beneficiaries with peri-hospitalization placement had the highest mortality and readmission rates 1- and 3-year post-implant (log-rank p < 0.0001), the magnitude of the associated risk did not differ significantly by race and ethnicity (p = NS for interaction). Conclusions: ICD implantation occurring during the peri-hospitalization period was associated with worse prognosis and occurred at higher rates among Black and Hispanic compared to White Medicare beneficiaries with HF during the period under study. The risk associated with peri-hospitalization ICD placement did not differ by race and ethnicity. Future paradigms aimed at enhancing real-world effectiveness of ICD therapy and addressing disparate outcomes should consider timing and setting of ICD placement in HFrEF patients who otherwise meet guideline eligibility.