Incidence of checkpoint inhibitor-associated inflammatory arthritis, immunomodulation and mortality in cancer patients on immunotherapy: a retrospective cohort study.

OBJECTIVES: Immune checkpoint inhibitor (ICI) associated inflammatory arthritis (ICI-IA) occurs in 4-6% of ICI-treated patients based on one observational study. We identified cases of ICI-IA using administrative claims to study its incidence and characteristics at the population level. METHODS: We used the Medicare 5% sample to identify patients initiating ICIs. Cancer patients were identified by having ≥ 2 ICD-9/10-CM diagnosis codes from an oncologist for lung cancer, melanoma, or renal/urothelial cancer. ICI-IA was defined as having two Medicare claims ≥ 30 days apart with combinations of ICD-9/10-CM diagnosis codes that favored specificity. ICI-IA was identified in patients with a musculoskeletal diagnosis after ICI initiation, who had i.) no inflammatory arthritis or inflammatory rheumatic disease before ICI initiation ever, and ii) no musculoskeletal complaint in the one year prior to ICI. We examined DMARD utilization and visits to rheumatology in patients with ICI-IA. Landmark analysis and a time varying Cox proportional hazards model for overall survival was constructed. RESULTS: The incidence of ICI-IA was 7.2 (6.1-8.4) per 100 patient years. Patients with ICI-IA were mean (SD) age 73.5(7.0) years, 48% women, 91% white. Median(IQR) time from ICI initiation to first ICI-IA diagnosis was 124(56, 252) days. Only 24(16%) received care from a rheumatologist, and 24(16%) were prescribed a DMARD (46% by a rheumatologist). The HR for mortality in patients with ICI-IA was 0.86 (95% CI 0.59-1.26, p= 0.45). CONCLUSIONS: The incidence of ICI-IA identified in claims data is similar to that reported in observational studies, however, few patients are treated with a DMARD or see a rheumatologist. There was no difference in overall survival between ICI-treated patients with and without ICI-IA.

Association Between Rheumatic Autoantibodies and Immune-Related Adverse Events.

BACKGROUND: Side effects of immune checkpoint inhibitors (ICIs), called immune-related adverse events (irAEs), closely resemble primary autoimmune or rheumatic diseases. We aimed to understand the clinical utility of rheumatic autoantibodies (rhAbs) for diagnosing irAEs. PATIENTS AND METHODS: Patients without pre-existing autoimmune disease (pAID) who had cancer treated with ICI(s) treatment from 1/1/2011 to 12/21/2020 and a rhAb checked were retrospectively identified. Logistic regression assessed associations between autoantibodies and irAEs, cancer outcome, and survival. Specificity, sensitivity, and positive/negative predictive values (PPV, NPV) were estimated for key rhAbs and ICI-arthritis. Kaplan-Meier analyzed objective response rate (ORR) and overall survival (OS). RESULTS: A total of 2662 patients were treated with≥1 ICIs. One hundred and thirty-five without pAID had ≥ 1 rhAb tested. Of which 70/135(52%) were female; median age at cancer diagnosis was 62 years with most common cancers: melanoma (23%) or non-small cell lung cancer (21%), 96/135 (75%) were anti-PD1/PDL1 treated. Eighty had a rhAb ordered before ICI, 96 after ICI, and 12 before and after. Eighty-two (61%) experienced an irAE, 33 (24%) with rheumatic-irAE. Pre-ICI RF showed significant association with rheumatic-irAEs (OR = 25, 95% CI, 1.52-410.86, P = .024). Pre- and post-ICI RF yielded high specificity for ICI-arthritis (93% and 78%), as did pre- and post-ICI CCP (100% and 91%). Pre-ICI RF carried 93% NPV and pre-ICI CCP had 89% PPV for ICI-arthritis. No variables were significantly correlated with ORR. Any-type irAE, rheumatic-irAE and ICI-arthritis were all associated with better OS (P = .000, P = .028, P = .019). CONCLUSIONS: Pre-ICI RF was associated with higher odds of rheumatic-irAEs. IrAEs had better OS; therefore, clinical contextualization for rhAbs is critical to prevent unnecessary withholding of lifesaving ICI for fear of irAEs.

Comparative safety and effectiveness of TNF inhibitors, IL6 inhibitors and methotrexate for the treatment of immune checkpoint inhibitor-associated arthritis.

OBJECTIVES: To compare the safety and effectiveness of biologic and conventional disease-modifying antirheumatic drugs (DMARDs) for immune checkpoint inhibitor-associated inflammatory arthritis (ICI-IA). METHODS: The retrospective multicentre observational study included patients with a diagnosis of ICI-IA treated with a tumour necrosis factor inhibitor (TNFi), interleukin-6 receptor inhibitor (IL6Ri) and/or methotrexate (MTX); patients with pre-existing autoimmune disease were excluded. The primary outcome was time to cancer progression from ICI initiation; the secondary outcome was time to arthritis control from DMARD initiation. Cox proportional hazard models were used to compare medication groups, adjusting for confounders. RESULTS: 147 patients were included (mean age 60.3 (SD 11.9) years, 66 (45%) women). ICI-IA treatment was TNFi in 33 (22%), IL6Ri 42 (29%) and MTX 72 (49%). After adjustment for time from ICI initiation to DMARD initiation, time to cancer progression was significantly shorter for TNFi compared with MTX (HR 3.27 (95% CI 1.21 to 8.84, p=0.019)) while the result for IL6Ri was HR 2.37 (95% CI 0.94 to 5.98, p=0.055). Time to arthritis control was faster for TNFi compared with MTX (HR 1.91 (95% CI 1.06 to 3.45, p=0.032)) while the result for IL6Ri was HR 1.66 (95% CI 0.93 to 2.97, p=0.089). A subset analysis in patients with melanoma gave similar results for both cancer progression and arthritis control. CONCLUSION: The treatment of ICI-IA with a biologic DMARD is associated with more rapid arthritis control than with MTX, but may be associated with a shorter time to cancer progression.

Healthcare disparities: patients' perspectives on barriers to joint replacement.

OBJECTIVE: Racial and ethnic disparities in arthroplasty utilization are evident, but the reasons are not known. We aimed to identify concerns that may contribute to barriers to arthroplasty from the patient's perspective. METHODS: We identified patients' concerns about arthroplasty by performing a mixed methods study. Themes identified during semi-structured interviews with Black and Hispanic patients with advanced symptomatic hip or knee arthritis were used to develop a questionnaire to quantify and prioritize their concerns. Multiple linear and logistic regression analyses were conducted to determine the association between race/ethnicity and the importance of each theme. Models were adjusted for sex, insurance, education, HOOS, JR/KOOS, JR, and discussion of joint replacement with a doctor. RESULTS: Interviews with eight participants reached saturation and provided five themes used to develop a survey answered by 738 (24%) participants; 75.5% White, 10.3% Black, 8.7% Hispanic, 3.9% Asian/Other. Responses were significantly different between groups (p < 0.05). Themes identified were "Trust in the surgeon" "Recovery", "Cost/Insurance", "Surgical outcome", and "Personal suitability/timing". Compared to Whites, Blacks were two-fold, Hispanics four-fold more likely to rate "Trust in the surgeon" as very/extremely important. Blacks were almost three times and Hispanics over six times more likely to rate "Recovery" as very/extremely important. CONCLUSION: We identified factors of importance to patients that may contribute to barriers to arthroplasty, with marked differences between Blacks, Hispanics, and Whites.

Black Patients are More Likely to Undergo Early Revision Total Knee Arthroplasty in a Matched Cohort Regardless of Surgeon Experience.

BACKGROUND: Black patients are at an increased risk of aseptic revision total knee arthroplasty (TKA) when compared to White patients. The goal of this study was to determine whether racial disparities in revision TKA risk are related to surgeon characteristics. METHODS: This was an observational cohort study. We used inpatient administrative data to identify Black patients who underwent unilateral primary TKA in New York State. There were 21,948 Black patients who were matched 1:1 to White patients on age, sex, ethnicity, and insurance type. The primary outcome was aseptic revision TKA within 2 years of primary TKA. We calculated annual surgeon TKA volume and identified surgeon characteristics such as training in North America, board certification, and years of experience. RESULTS: Black patients had a higher odds of aseptic revision TKA (odds ratio (OR) 1.32, 95% CI 1.12-1.54, P < .001) and were disproportionately cared for by low volume surgeons (≤12 TKA/year). The relationship between low volume surgeons and risk of aseptic revision was not statistically significant (OR 1.24, 95% CI 0.72-2.11, P = .436). The adjusted odds ratio (aOR) for aseptic revision TKA in Black versus White patients varied across surgeon/hospital TKA volume category pairs, with the greatest aOR when TKA were performed by the highest volume surgeons at the highest volume hospitals (aOR 2.8, 95% CI 0.98- 8.09, P = .055). CONCLUSION: Black patients were more likely to undergo aseptic TKA revision than matched White patients. This disparity was not explained by surgeon characteristics.

Autoantibodies in Patients With Immune-Related Adverse Events From Checkpoint Inhibitors: A Systematic Literature Review.

BACKGROUND: Immune-related adverse events (irAEs) from immune checkpoint inhibitors (ICIs) are sometimes associated with autoantibodies, but we do not know how frequently or whether these autoantibodies are present before ICI initiation. Our aim was to determine the positivity rate of autoantibodies in patients with organ-specific ICI-associated irAEs and determine their value as pretreatment biomarkers. METHODS: We searched for all English, peer-reviewed publications from MEDLINE, Embase, and Cochrane Library through February 20, 2020, and included any publication describing patients with irAEs and reporting results of any autoantibody investigation. Three reviewers independently extracted data, and 1 reviewer verified all data for accuracy and quality of reporting. RESULTS: We identified 515 publications. Most reports described endocrine, rheumatic, gastrointestinal/hepatic, and myositis/myasthenia/myocarditis irAEs. Autoantibodies were present in close to 50% of patients with ICI-associated endocrinopathies. Anti-BP180 was found in more than 50% of patients with skin irAEs. Antibodies were also common in patients with the triad of myositis/myasthenia/myocarditis including striational antibodies (49%), acetylcholine receptor antibodies (40%), and myositis-associated antibodies (27%). Only 11% of patients with arthritis had either rheumatoid factor or cyclic citrullinated peptide antibodies, and only 30% of patients with sicca had Sjögren antibodies. Autoantibodies were also relatively uncommon in patients with hepatitis (antinuclear antibody, 18%) and colitis (perinuclear antineutrophil cytoplasmic antibody, 19%). Some cohort studies analyzing pre-ICI seropositivity suggest there may be a role for autoantibodies as biomarkers of irAEs. CONCLUSIONS: Reported autoantibody positivity is high in irAEs involving the endocrine organs, skin, and muscle, but lower in irAEs affecting other organ systems. Autoantibody investigations in pre-ICI treatment patients have yielded mixed results regarding their utility as a biomarker of irAEs.

Checkpoint Inhibitor-Associated Arthritis: A Systematic Review of Case Reports and Case Series.

OBJECTIVE: We performed a systematic literature review to identify all reports of immune checkpoint inhibitor-associated inflammatory arthritis to describe it phenotypically and serologically. METHODS: PubMed, Embase, and Cochrane databases were searched for reports of musculoskeletal immune-related adverse events secondary to ICI treatment. Publications were included if they provided individual patient level data regarding the pattern of joint involvement. Descriptive statistics were used to summarize results. RESULTS: A total of 4339 articles were screened, of which 67 were included, encompassing 372 patients. The majority of patients had metastatic melanoma (57%), and they were treated with anti-PD1 or anti-PDL1 therapy (78%). Median time to onset of arthritis was 4 months (range, 1 day to 53 months). Forty-nine percent had polyarthritis, 17% oligoarthritis, 3% monoarthritis, 10% arthralgia, and 21% polymyalgia rheumatica. More than half of patients were described as having a "rheumatoid arthritis-like" presentation. Nine percent tested positive for rheumatoid factor or anti-cyclic citrullinated peptide antibodies. Seventy-four percent required corticosteroids, and 45% required additional medications. Sixty-three percent achieved arthritis control, and 32% were ultimately able to discontinue antirheumatic treatments. Immune checkpoint inhibitors were continued in 49%, transiently withheld in 11%, and permanently discontinued due to musculoskeletal immune-related adverse events in 13%. CONCLUSIONS: Half of reported immune checkpoint inhibitor-associated arthritis cases present with polyarthritis (often RA-like), but only 9% are seropositive. Polymyalgia rheumatica is also common. Most patients respond to steroids alone, but about half require additional medications. Further studies are needed to determine long-term musculoskeletal outcomes in these patients, and the impact of arthritis treatment on cancer survival.

Variables Associated With Perceived Risk of Contracting SARS-CoV-2 Infection During the COVID-19 Pandemic Among Patients With Systemic Rheumatic Diseases.

OBJECTIVE: The aim of this study was to assess patients' perceived risk of contracting SARS-CoV-2 at the peak of the pandemic in NYC in terms of their systemic rheumatic disease and medications. METHODS: With the approval of their rheumatologists, patients were interviewed by telephone and were asked about their perceived risk of contracting SARS-CoV-2 considering their rheumatic condition and whether medications increased this risk. Patients also completed surveys assessing beliefs about medication and multidimensions of physical/mental well-being. Information about current medications and rheumatologist-initiated changes in medications during the pandemic were reported by patients and verified from medical records. RESULTS: One hundred twelve patients (86% women; mean age, 50 years; 81% White, 15% Latino) with diverse diagnoses were enrolled. Fifty-four percent thought they were at "very much greater risk" of COVID-19 because of their rheumatic condition, and 57% thought medications "definitely" put them at greater risk. In multivariable analysis, the perception of "very much greater risk" was associated with greater belief that rheumatic disease medications were necessary, worse physical function, chronic pulmonary comorbidity, and more anxiety. In a separate model, the perception that medications "definitely" caused greater risk was associated with White race, not taking hydroxychloroquine, rheumatologists initiating change in medications, more anxiety, and taking biologics and corticosteroids. CONCLUSIONS: Patients' perceived increased risk of contracting SARS-CoV-2 was associated with beliefs about their rheumatic disease, medications, comorbidity, and anxiety. Clinicians should be aware of patients' perceptions and foster self-management practices that will alleviate anxiety, minimize exposure to the virus, and optimize systemic rheumatic disease outcomes.

Eosinophilic Fasciitis Following Checkpoint Inhibitor Therapy: Four Cases and a Review of Literature.

BACKGROUND: Checkpoint inhibitor therapy is widely known to cause a number of immune-related adverse events. One rare adverse effect that is emerging is eosinophilic fasciitis, a fibrosing disorder causing inflammatory infiltration of subcutaneous fascia. It is characterized clinically by edema and subsequent induration and tightening of the skin and subcutaneous tissues. The condition is rare, yet at our institutions we have seen four cases in the past 3 years. We describe our 4 cases and review 11 other cases reported in the literature. CASE PRESENTATION: We present four cases of eosinophilic fasciitis following treatment with programmed cell death protein 1 or programmed cell death-ligand 1 blockade. All patients had extremity involvement with characteristic skin changes ranging from peripheral edema to induration, tightening, and joint limitation. The patients had varying degrees of peripheral eosinophilia. In two of our patients, the diagnosis was made by full-thickness skin biopsy showing lymphocytic infiltration of the subcutaneous fascia, with CD4+ T cells predominating in one case and CD8+ T cells in the other. In the other two cases, the diagnosis was made on the basis of characteristic imaging findings in the context of clinical features consistent with the diagnosis. All four patients were treated with glucocorticoids with varying degrees of success; immunotherapy had to be discontinued in all four. Patients with advanced melanoma who experienced this adverse effect had either a partial response or a complete response to therapy. CONCLUSION: Eosinophilic fasciitis can occur as a result of checkpoint inhibitor therapy. Although a tissue diagnosis is the gold standard, imaging studies may facilitate the diagnosis in the presence of consistent clinical features, but a degree of suspicion is key to recognizing the condition early. Therapy requires a collaborative approach by oncology, rheumatology, and dermatology; physical therapy is an important adjunct in treatment. For advanced melanoma, it may be a good prognostic indicator. IMPLICATIONS FOR PRACTICE: It is important for clinicians to recognize that eosinophilic fasciitis is a potential immune-related adverse event (irAE) as a consequence of immune checkpoint inhibitor therapy. The presentation is quite stereotypical; the diagnosis can be made by imaging in the absence of a full-thickness skin biopsy. Early intervention is important to limit morbidity. This irAE may be a good prognostic sign among patients with melanoma.

Living in immigrant communities does not impact total knee arthroplasty outcomes: experience from a high-volume center in the United States.

BACKGROUND: Community characteristics such as poverty affect total knee arthroplasty (TKA) outcomes. However, it is unknown whether other community factors such as immigrant proportion (IP) also affect outcomes. Our objective was to determine the association of neighborhood IP on preoperative (pre-op) and 2-year postoperative (post-op) Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function after elective TKA. METHODS: Patients in a high volume institutional TKA registry between May 2007 and February 2011 were retrospectively analyzed. Demographics, pre-op and 2-year post-op WOMAC pain and function scores, and geocodable addresses were obtained. Patient-level variables were linked to US Census Bureau census tract data. The effect of patient and neighborhood-level factors on WOMAC scores were analyzed using linear mixed effects models. RESULTS: 3898 TKA patients were analyzed. Pre-op and 2-year post-op WOMAC pain and function scores were between 2.75-4.88 WOMAC points worse in neighborhoods with a high IP (≥ 40%) compared to low IP (< 10%). In multivariable analyses, these differences were not statistically significant. Women had worse pre-op and 2-year post-op WOMAC scores (all p ≤ 0.04), but this difference was not influenced by neighborhood IP (all pinteraction NS). CONCLUSIONS: Patients living in high (≥40%) IP neighborhoods do not have worse pre-op or 2-year post-op pain and function outcomes after TKA compared to those living in low (< 10%) IP neighborhoods. Although sex differences favoring males are notable, these differences are not associated with IP. High neighborhood IP do not appear to affect outcomes after TKA.

Increased Staphylococcus aureus Nasal Carriage Rates in Rheumatoid Arthritis Patients on Biologic Therapy.

BACKGROUND: Rheumatoid arthritis patients are at increased risk for periprosthetic joint infection after arthroplasty. The reason is multifactorial. Nasal colonization with Staphylococcus aureus is a modifiable risk factor; carriage rates in RA patients are unknown. The goal of this study is to determine the S aureus nasal carriage rates of RA patients on biologics, RA patients on traditional disease-modifying anti-rheumatic drugs (DMARDs), and osteoarthritis. METHODS: Consecutive patients with RA on biologics (±DMARDs), RA on non-biologic DMARDs, or OA were prospectively enrolled from April 2017 to May 2018. One hundred twenty-three patients were determined necessary per group to show a difference in carriage rates. Patients underwent a nasal swab and answered questions to identify additional risk factors. S aureus positive swabs were further categorized using spa typing. Logistic regression evaluated the association with S aureus colonization between the groups after controlling for known risk factors. RESULTS: RA patients on biologics, 70% of whom were on DMARDs, had statistically significant increase in S aureus colonization (37%) compared to RA on DMARDs alone (24%), or OA (20%) (P = .01 overall). After controlling for glucocorticoids, antibiotic use, recent hospitalization, and diabetes, RA on biologics had a significant increased risk of S aureus nasal colonization (Odds ratio 1.80, 95% confidence interval 1.00-3.22, P = .047). CONCLUSION: S aureus colonization risk was increased for RA on biologics compared to RA not on biologics and OA. Nasal S aureus carriage increases the risk of surgical site infection; this modifiable risk factor should be addressed prior to total joint arthroplasty for this higher risk patient group.

Effect of Low-Intensity vs Standard-Intensity Warfarin Prophylaxis on Venous Thromboembolism or Death Among Patients Undergoing Hip or Knee Arthroplasty: A Randomized Clinical Trial.

Importance: The optimal international normalized ratio (INR) to prevent venous thromboembolism (VTE) in warfarin-treated patients with recent arthroplasty is unknown. Objective: To determine the safety and efficacy of a target INR of 1.8 vs 2.5 for VTE prophylaxis after orthopedic surgery. Design, Setting, and Participants: The randomized Genetic Informatics Trial (GIFT) of Warfarin to Prevent Deep Vein Thrombosis enrolled 1650 patients aged 65 years or older initiating warfarin for elective hip or knee arthroplasty at 6 US medical centers. Enrollment began in April 2011 and follow-up concluded in October 2016. Interventions: In a 2 × 2 factorial design, participants were randomized to a target INR of 1.8 (n = 823) or 2.5 (n = 827) and to either genotype-guided or clinically guided warfarin dosing. For the first 11 days of therapy, open-label warfarin dosing was guided by a web application. Main Outcomes and Measures: The primary outcome was the composite of VTE (within 60 days) or death (within 30 days). Participants underwent screening duplex ultrasound postoperatively. The hypothesis was that an INR target of 1.8 would be noninferior to an INR target of 2.5, using a noninferiority margin of 3% for the absolute risk of VTE. Secondary end points were bleeding and INR values of 4 or more. Results: Among 1650 patients who were randomized (mean age, 72.1 years; 1049 women [63.6%]; 1502 white [91.0%]), 1597 (96.8%) received at least 1 dose of warfarin and were included in the primary analysis. The rate of the primary composite outcome of VTE or death was 5.1% (41 of 804) in the low-intensity-warfarin group (INR target, 1.8) vs 3.8% (30 of 793) in the standard-treatment-warfarin group (INR target, 2.5), for a difference of 1.3% (1-sided 95% CI, -∞ to 3.05%, P = .06 for noninferiority). Major bleeding occurred in 0.4% of patients in the low-intensity group and 0.9% of patients in the standard-intensity group, for a difference of -0.5% (95% CI, -1.6% to 0.4%). The INR values of 4 or more occurred in 4.5% of patients in the low-intensity group and 12.2% of the standard-intensity group, for a difference of -7.8% (95% CI, -10.5% to -5.1%). Conclusions and Relevance: Among older patients undergoing hip or knee arthroplasty and receiving warfarin prophylaxis, an international normalized ratio goal of 1.8 compared with 2.5 did not meet the criterion for noninferiority for risk of the composite outcome of VTE or death. However, the trial may have been underpowered to meet this criterion and further research may be warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT01006733.

Does my patient have a pulmonary embolism? The Wells vs. PISA 2 rule in orthopedic patients.

The diagnosis of venous thromboembolism is difficult in the postoperative setting because signs such as hypoxemia, leg pain, and swelling are so common. CTPA can also detect subsegmental PE (SSPE), of which the clinical significance has been widely debated. Clinical decision rules (CDR), such as the Wells and PISA 2, have been developed to identify symptomatic patients at low risk for PE who could forgo imaging. We performed this study in order to (1) compare the performance of the Wells and PISA 2 CDR in orthopedic patients; (2) compare CDR scores in patients with subsegmental PE (SSPE) versus larger clots; and (3) identify variables that improve performance of the Wells in orthopedic patients. This retrospective cohort study included all orthopedic surgery patients that underwent computerized tomographic pulmonary angiography at a single institution from 1/1/13 to 12/31/14 and had data to calculate both Wells and PISA 2 scores. CDR sensitivity, specificity and c-statistics were calculated. Multivariable logistic regression was used to identify variables that improved CDR performance. 402 patients were included in the study. The Wells rule (cutoff > 4) had sensitivity 74% and specificity 45%. PISA 2 (cutoff 0.6) had sensitivity 90% and specificity 11%. The Wells performed better than PISA 2: c-statistic 0.60 vs. 0.50; p = 0.007. The mean Wells score was 5.20 ± 1.68 for patients with SSPE and 5.41 ± 1.86 for patients with larger clots. Adding the variables prior smoking and varicose veins improved the performance of the Wells rule (c-statistic 0.66 vs. 0.60, p = 0.008). The Wells rule (cutoff > 4) performs better than PISA 2 in orthopedic patients. Neither can distinguish patients with SSPE from those with larger clots. Although adding past smoking and varicose veins to the Wells improves its performance, this requires validation in other populations.

Effect of Genotype-Guided Warfarin Dosing on Clinical Events and Anticoagulation Control Among Patients Undergoing Hip or Knee Arthroplasty: The GIFT Randomized Clinical Trial.

Importance: Warfarin use accounts for more medication-related emergency department visits among older patients than any other drug. Whether genotype-guided warfarin dosing can prevent these adverse events is unknown. Objective: To determine whether genotype-guided dosing improves the safety of warfarin initiation. Design, Setting, and Patients: The randomized clinical Genetic Informatics Trial (GIFT) of Warfarin to Prevent Deep Vein Thrombosis included patients aged 65 years or older initiating warfarin for elective hip or knee arthroplasty and was conducted at 6 US medical centers. Enrollment began in April 2011 and follow-up concluded in October 2016. Interventions: Patients were genotyped for the following polymorphisms: VKORC1-1639G>A, CYP2C9*2, CYP2C9*3, and CYP4F2 V433M. In a 2 × 2 factorial design, patients were randomized to genotype-guided (n = 831) or clinically guided (n = 819) warfarin dosing on days 1 through 11 of therapy and to a target international normalized ratio (INR) of either 1.8 or 2.5. The recommended doses of warfarin were open label, but the patients and clinicians were blinded to study group assignment. Main Outcomes and Measures: The primary end point was the composite of major bleeding, INR of 4 or greater, venous thromboembolism, or death. Patients underwent a screening lower-extremity duplex ultrasound approximately 1 month after arthroplasty. Results: Among 1650 randomized patients (mean age, 72.1 years [SD, 5.4 years]; 63.6% women; 91.0% white), 1597 (96.8%) received at least 1 dose of warfarin therapy and completed the trial (n = 808 in genotype-guided group vs n = 789 in clinically guided group). A total of 87 patients (10.8%) in the genotype-guided group vs 116 patients (14.7%) in the clinically guided warfarin dosing group met at least 1 of the end points (absolute difference, 3.9% [95% CI, 0.7%-7.2%], P = .02; relative rate [RR], 0.73 [95% CI, 0.56-0.95]). The numbers of individual events in the genotype-guided group vs the clinically guided group were 2 vs 8 for major bleeding (RR, 0.24; 95% CI, 0.05-1.15), 56 vs 77 for INR of 4 or greater (RR, 0.71; 95% CI, 0.51-0.99), 33 vs 38 for venous thromboembolism (RR, 0.85; 95% CI, 0.54-1.34), and there were no deaths. Conclusions and Relevance: Among patients undergoing elective hip or knee arthroplasty and treated with perioperative warfarin, genotype-guided warfarin dosing, compared with clinically guided dosing, reduced the combined risk of major bleeding, INR of 4 or greater, venous thromboembolism, or death. Further research is needed to determine the cost-effectiveness of personalized warfarin dosing. Trial Registration: clinicaltrials.gov Identifier: NCT01006733.

Disparities in TKA Outcomes: Census Tract Data Show Interactions Between Race and Poverty.

BACKGROUND: Race is an important predictor of TKA outcomes in the United States; however, analyses of race can be confounded by socioeconomic factors, which can result in difficulty determining the root cause of disparate outcomes after TKA. QUESTIONS/PURPOSES: We asked: (1) Are race and socioeconomic factors at the individual level associated with patient-reported pain and function 2 years after TKA? (2) What is the interaction between race and community poverty and patient-reported pain and function 2 years after TKA? METHODS: We identified all patients undergoing TKA enrolled in a hospital-based registry between 2007 and 2011 who provided 2-year outcomes and lived in New York, Connecticut, or New Jersey. Of patients approached to participate in the registry, more than 82% consented and provided baseline data, and of these patients, 72% provided 2-year data. Proportions of patients with complete followup at 2 years were lower among blacks (57%) than whites (74%), among patients with Medicaid insurance (51%) compared with patients without Medicaid insurance (72%), and among patients without a college education (67%) compared with those with a college education (71%). Our final study cohort consisted of 4035 patients, 3841 (95%) of whom were white and 194 (5%) of whom were black. Using geocoding, we linked individual-level registry data to US census tracts data through patient addresses. We constructed a multivariate linear mixed-effect model in multilevel frameworks to assess the interaction between race and census tract poverty on WOMAC pain and function scores 2 years after TKA. We defined a clinically important effect as 10 points on the WOMAC (which is scaled from 1 to 100 points, with higher scores being better). RESULTS: Race, education, patient expectations, and baseline WOMAC scores are all associated with 2-year WOMAC pain and function; however, the effect sizes were small, and below the threshold of clinical importance. Whites and blacks from census tracts with less than 10% poverty have similar levels of pain and function 2 years after TKA (WOMAC pain, 1.01 ± 1.59 points lower for blacks than for whites, p = 0.53; WOMAC function, 2.32 ± 1.56 lower for blacks than for whites, p = 0.14). WOMAC pain and function scores 2 years after TKA worsen with increasing levels of community poverty, but do so to a greater extent among blacks than whites. Disparities in pain and function between blacks and whites are evident only in the poorest communities; decreasing in a linear fashion as poverty increases. In census tracts with greater than 40% poverty, blacks score 6 ± 3 points lower (worse) than whites for WOMAC pain (p = 0.03) and 7 ± 3 points lower than whites for WOMAC function (p = 0.01). CONCLUSIONS: Blacks and whites living in communities with little poverty have similar patient-reported TKA outcomes, whereas in communities with high levels of poverty, there are important racial disparities. Efforts to improve TKA outcomes among blacks will need to address individual- and community-level socioeconomic factors. LEVEL OF EVIDENCE: Level III, therapeutic study.

Using new oral anticoagulants in patients undergoing major orthopedic surgery.

Four new oral anticoagulants (NOAC), apixaban, rivaroxaban, edoxaban, and dabigatran, are now available in the USA; however, only apixaban and rivaroxaban are FDA approved for the prevention of venous thromboembolism following orthopedic surgery. Apixaban, rivaroxaban, and edoxaban's anticoagulant activity can be measured using a chromogenic anti-factor Xa assay but there is no widely available means of measuring dabigatran blood levels. None of the NOAC has an antidote. Dabigatran is 80% renally excreted, and patients with atrial fibrillation taking dabigatran for stroke prevention should stop the drug 4-5 days prior to major orthopedic surgery. Apixaban, rivaroxaban, and edoxaban should be held for 48 h preoperatively in this setting.