AbstractHigher and lower hemoglobin concentrations are associated with coronary heart disease (CHD), but whether this risk is consistent across age, sex, and race is unclear. The Reasons for Geographic And Racial Differences in Stroke (REGARDS) study is an observational cohort study of 30 239 black, and white, adults aged 45 and older recruited 2003‐7. Participants were included if they had hemoglobin measures, were CHD‐free at baseline, and had all baseline variables. The primary outcome was incident CHD. Multivariable Cox proportional hazards models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for incident CHD by hemoglobin concentration. This was expressed as a continuous variable and divided into age‐, sex‐, and race‐specific quintiles. The 16 332 participants were included, contributing 114 362 person‐years of follow‐up and 915 incident CHD events. The mean age was 63 years, 35% were male, 41% were black, and the mean baseline hemoglobin was 13.6 g/dL (SD 1.4). A significant non‐linear association between hemoglobin and CHD was identified (P < .001). This association differed significantly by race (P = .025) but not by sex or age. In whites, the risk for incident CHD was higher in the lowest (HR 2.28, 95% CI 1.61, 3.33) and highest (HR 1.94, 95% CI 1.35, 2.79) hemoglobin quintiles relative to the third quintile. For blacks, only those in the lowest hemoglobin quintile had an increased risk for incident CHD events (HR 1.70, 95% CI 1.20, 2.41). Hemoglobin is an independent risk factor for CHD in whites and blacks but with different hemoglobin concentrations conferring different risks.
Anti–PD-L1 antibody direct activation of macrophages contributes to a radiation-induced abscopal response in glioblastoma
Abstract Background Most glioblastomas recur near prior radiation treatment sites. Future clinical success will require achieving and optimizing an “abscopal effect,” whereby unirradiated neoplastic cells outside treatment sites are recognized and attacked by the immune system. Radiation combined with anti–programmed cell death ligand 1 (PD-L1) demonstrated modest efficacy in phase II human glioblastoma clinical trials, but the mechanism and relevance of the abscopal effect during this response remain unknown. Methods We modified an immune-competent, genetically driven mouse glioma model (forced platelet derived growth factor [PDGF] expression + phosphatase and tensin homolog loss) where a portion of the tumor burden is irradiated (PDGF) and another unirradiated luciferase-expressing tumor (PDGF + luciferase) is used as a readout of the abscopal effect following systemic anti–PD-L1 immunotherapy. We assessed relevance of tumor neoepitope during the abscopal response by inducing expression of epidermal growth factor receptor variant III (EGFRvIII) (PDGF + EGFRvIII). Statistical tests were two-sided. Results Following radiation of one lesion, anti–PD-L1 immunotherapy enhanced the abscopal response to the unirradiated lesion. In PDGF-driven gliomas without tumor neoepitope (PDGF + luciferase, n = 8), the abscopal response occurred via anti–PD-L1 driven, extracellular signal-regulated kinase–mediated, bone marrow–derived macrophage phagocytosis of adjacent unirradiated tumor cells, with modest survival implications (median survival 41 days vs radiation alone 37.5 days, P = 0.03). In PDGF-driven gliomas with tumor neoepitope (PDGF + EGFRvIII, n = 8), anti–PD-L1 enhanced abscopal response was associated with macrophage and T-cell infiltration and increased survival benefit (median survival 36 days vs radiation alone 28 days, P = 0.001). Conclusion Our results indicate that anti–PD-L1 immunotherapy enhances a radiation- induced abscopal response via canonical T-cell activation and direct macrophage activation in glioblastoma.
Peripheral Blood Cytopenia and Subsequent Risk of Cardiovascular Disease and Mortality
INTRODUCTION: African-Americans (blacks) have higher risk of stroke and coronary heart disease (CHD) - collectively referred to here as cardiovascular disease (CVD), than Caucasian-Americans (whites). Though partly explained by traditional cardiovascular risk factors, half of the excess risk in blacks is not explained by known risk factors. Recent data suggest increased risk of CVD and mortality in individuals with clonal hematopoiesis, which often presents as cytopenia. Using peripheral blood cytopenia as a marker of clonal hematopoiesis, we examined the association between cytopenia and risk of CVD and mortality in blacks and whites. METHODS: The REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort study enrolled 30,239 US black and white adults between 2003 and 2007 (41% black). Socio-demographics and medical history were obtained by telephone interview, and laboratory studies (including complete blood count [CBC]) and physical exam from an in-home visit at baseline. Participants or their proxies were contacted every 6 months to ascertain CVD events, hospitalizations or deaths, and medical records were reviewed to confirm these events. Cytopenia was defined using thresholds in Table 1 as presence of 2 or more of the following: i) hemoglobin in age-, sex-, and race-specific lowest 5th percentile; ii) white cell count in race-specific lowest 5th percentile; iii) platelet count in lowest 5th percentile, and iv) macrocytosis (MCV >98fL). Participants with pre-baseline history of stroke (for analyses including stroke or CVD mortality) or CHD (for analyses including CHD or CVD mortality) and those with missing CBC were excluded. Cox proportional hazards models were used to calculate hazard ratios (HRs) of incident CVD and mortality associated with cytopenia. Models adjusted for socio-demographics (Model 1), Framingham stroke or CHD risk factors (Model 2), and estimated glomerular filtration rate and C-reactive protein (Model 3) were used. Differences in the association of cytopenia with outcomes by race were tested using cross-product interaction terms, using a p of <0.1 for interaction. RESULTS: The study included 19,544 participants who were followed for a median of ~9 years. There were 798 (4.3% of those at risk) incident stroke cases and 727 (4.3%) incident CHD cases; 1033 (5.3%) died of CVD, and 3933 (20.1%) died of all-causes. Cytopenia was present in 378 (1.9%) participants, ranging from 0.9% to 3.5% in blacks, 1.4 to 3.9% in whites, 1.6 to 3.9% in men, and 0.9 to 1.8% in women, with increasing prevalence by age. There was no association between cytopenia and stroke or CHD risk in any model. However, cytopenia was associated with increased risk of all-cause mortality (HR=1.73, 95%CI: 1.34-2.22), and CVD mortality (HR=1.56, 95% CI: 1.11-2.19) in the extended risk factor Model 3 and also in CVD risk factor adjusted model (Model 2), with little evidence of confounding (Table 2). While the race by cytopenia interaction term was not significant in any model for incident CHD or mortality, the interaction for cytopenia by race for stroke was statistically significant (p-interaction=0.08) in Model 2. The HR of stroke for cytopenia in blacks was 0.86 (95%CI: 0.46-1.61), and for whites was 1.96 (95%CI: 1.0-3.82). CONCLUSION: In this large biracial cohort, cytopenia was associated with increased all-cause and CVD mortality. Cytopenia was a race-specific risk factor for stroke affecting white Americans but not black Americans. With growing knowledge on the role of clonal hematopoiesis in CVD risk and mortality, further work is needed to determine if our phenotype of cytopenia is accurate in classifying clonal hematopoiesis and for determining the mortality risk. Given these findings, assessing clonal hematopoiesis and outcomes related to clonal hematopoiesis in diverse populations is critical to understanding the interactions between somatic mutations in hematopoietic cells and CVD/mortality risk. Disclosures Safford: Amgen: Research Funding.
Treatment of Upper Extremity Deep Vein Thrombosis with Apixaban and Rivaroxaban
Background: Randomized controlled trials leading to the approval of apixaban and rivaroxaban for venous thromboembolism (VTE) did not include patients with UE-DVT. Limited observational data has been published on outcomes in this setting and no direct comparison to traditional anticoagulation has been performed. Objective: Evaluate the safety and effectiveness of rivaroxaban and apixaban for the treatment of acute UE-DVT compared to low-molecular weight (LWMH) and warfarin. Methods: Consecutive patients with VTE were enrolled into the Mayo Clinic VTE Registry, between March 1, 2013 and July 22, 2019, were followed prospectively. Clinical, demographic and imaging data were collected at the time of study recruitment. Patients with a diagnosis of acute UE-DVT who received either rivaroxaban, apixaban, LMWH or warfarin within the first 14 days after diagnosis and who completed at least 3 months of anticoagulant therapy or had an outcome event in that period were included into the analysis. Recurrent VTE, major bleeding, clinical relevant non-major bleeding (CRNMB), and death were assessed at 3 months, in person whenever feasible, or by mailing a written questionnaire or a scripted phone interview. The study was approved by Mayo Clinic Institutional Review Board. Results: One hundred and thirty-four patients with acute UE-DVT were included. Forty-one were treated with apixaban, 32 with rivaroxaban, and 61 with LWMH and/or warfarin. The mean age was 58.3 years, mean BMI was 28.2, and 59% were male (Table 1). Patients treated with LMWH / warfarin were older (61.3 vs 55.8, p=0.04) and had a lower BMI (27.1 vs 29.0, p=0.0496). Twenty-six (19%) patients had catheter-associated UE-DVT, 93 (69.4%) had a diagnosis of malignancy, and 16 (11.9%) had concurrent pulmonary embolism, which were similar between groups. More patients on apixaban /rivaroxaban were receiving chemotherapy (53.4% vs 47.5%, p=0.04) and had recent surgery (13.7% vs 3.3%, p=0.04) compared to LMWH / warfarin. At 3 months of follow up, 1 recurrent VTE occurred in patients treated with LMWH /warfarin and none of those treated with apixaban /rivaroxaban (p=0.27). Major bleeding occurred in 2 patients treated with LMWH /warfarin and in none of those treated with apixaban /rivaroxaban (p=0.12). CRNMB occurred in 1 patient treated with LWMH /warfarin and 5 patients treated with apixaban / rivaroxaban (p=0.15). Two of the CRNMBs occurred with rivaroxaban and 3 occurred with apixaban. Death occurred in 5 patients treated with LMWH /warfarin and in none of the apixaban /rivaroxaban treated patients (p=0.01). Conclusion: This single institution prospective study adds to the limited experience with apixaban and rivaroxaban for acute UE-DVT. Treatment of UE-DVT with rivaroxaban and apixaban appears to be as safe and effective as LMWH/warfarin after 3 months of anticoagulation. Disclosures McBane: BMS: Research Funding.
Incidental Pulmonary Embolism. Analysis of Mayo Clinic Venous Thromboembolism Database
Background: Incidental pulmonary embolism (PE) is not infrequently found on CT scans with highest incidence reported in patients with cancer. It is unclear whether patients with symptomatic pulmonary embolism (iPE) have different clinical profile or outcomes compared to patients with symptomatic PE (sPE) and whether this is affected by the presence or type of malignancy. Objective: Compare baseline characteristics of patients diagnosed with iPE to patients with sPE with attention to cancer-specific risk factors as well as evaluate clinical outcomes. Methods: Consecutive patients enrolled in the Mayo Thrombophilia Clinic VTE Registry between March 1, 2013 and December 31st, 2018 with PE were followed prospectively. Outcomes of recurrent venous thromboembolism (VTE), major bleeding, clinically relevant non-major bleeding (CRNMB) and mortality data were collected every 3 months. Clinical outcomes were analyzed with specific focus on patients with cancer. Information was collected and managed using REDCap (Research Electronic Data Capture) and data analysis was performed using SAS software (SAS Institute Inc., Cary, North Carolina). Results: Out of a total of 1033 patients with PE in VTE registry, there were 655 patients with PE (284 with incidental and 363 symptomatic) who completed at least 3 months of anticoagulation and were started on treatment within 14 days of diagnosis. Apixaban was used in 220 (34 %), Rivaroxaban 175 (27 %), Enoxaparin 179 (27%), and Warfarin in 81 (12 %) patients. Overall cancer was present in 61% of patients and was more common in patients with iPE compared to sPE (80.2% vs 45.2%, p<0.001). Patients with iPE were less likely to have previous VTE (8.2% vs 25.5%, p< 0.0001) and tended to have lower BMI (mean 28.8 vs 31.4, p<0.0001) Characteristics of the subgroup of only cancer patients with PE are summarized in the Table. Of note, pancreatic and GI cancers were more common in patients with iPE. There were no differences in recurrent VTE, major bleeding and CRNMB in patients with iPE compared to sPE. This also held true for patients with underlying malignancies. Mortality rates were significantly higher in all patients with iPE even when adjusting for presence of malignancy (p=0.03). When adjusting for presence of metastatic malignancy though the difference was no longer present (p=0.33). Conclusion: Patients with iPE were more likely to have an underlying malignancy, potentially due to higher likelihood of undergoing staging imaging studies. Additionally, patients with iPE more often had metastatic disease which was associated with higher mortality. Recurrent VTE and bleeding outcomes were similar in patients with iPE and sPE, this was independent of the presence of underlying malignancy. Disclosures McBane: BMS: Research Funding.
Cancer-Associated Thrombosis and Bleeding Risk in Gastrointestinal Malignancies with Apixaban and Rivaroxaban Compared to Low Molecular Weight Heparin
Abstract Background: Randomized control trials (RCT) have examined the safety and efficacy of direct oral anticoagulants (DOACs) compared to dalteparin in patients with cancer-associated thrombosis (CAT). Increased major bleeding (MB) was seen with edoxaban and increased clinically relevant non-major bleeding (CRNMB) was seen with rivaroxaban and there has been specific concern about increased risk of bleeding among patients with gastrointestinal malignancies (GIM). Results from RCTs comparing apixaban to dalteparin in CAT are pending. Objective: Using the Mayo Clinic VTE registry, we examined the rates of MB, CRNMB, and overall bleeding (MB + CRNMB) in patients with GIM treated with anticoagulation for CAT. Methods: Consecutive patients treated for CAT were enrolled into Mayo Clinic VTE Registry between March 1, 2013 and July 27, 2018 and were followed prospectively for safety and efficacy. Clinical, demographic and imaging data were collected from each participant at the time of study recruitment. Cancer type, stage, and treatment with chemotherapy were recorded. Major and CRNMB events were evaluated at 3-month intervals. Clinical status was assessed by written questionnaire in subjects unable to return at 3 months. Unreturned questionnaires were followed up with a scripted phone interview. The study was approved by Mayo Clinic Institutional Review Board. Results: In the 535 subjects in the registry with CAT, the mean age (64.6 vs. 62.8 years), mean BMI (28.4 vs. 28.8), and percent female (46.4% vs 40.6%) were numerically similar between DOAC and LMWH treatment groups (Table 1). Metastatic disease was present in 53.6% and 60.2% and chemotherapy was being administered in 66.5% and 71.2% of DOAC and LMWH treated patients, respectively. Thrombocytopenia (<100x109/L) at initiation of anticoagulation was present in 6.8% of DOAC treated and 7.5% of LMWH treated patients. Among all cancer patients, 110 (21%) patients had a GIM, 58 (53%) were treated with LWMH and 52 (47%) were treated with a DOAC (42% rivaroxaban or 58% apixaban). In all CAT, the rate of MB was similar in DOAC versus LMWH treated patients (7.8 vs. 5.4 per 100 person-years; HR 1.48, 95% CI 0.72-3.05; Table 2). The rate of CRNMB however, was significantly increased in the DOAC patients compared to LMWH treated patients (6.18 vs. 0.44 per 100 person-years; HR 14.7, 95% CI 1.92, 112.26). In the sub-group of patients with GIM, the rate of MB was non-significantly higher in the DOAC versus LMWH treated patients (11.1 vs. 3.9 per 100 person-years; HR 2.90, 95% CI 0.57, 14.73). In contrast to the overall CAT group, the rate of CRNMB was similar in the DOAC compared to LMWH treated patients (2.10 vs. 1.92 per 100 person-years; HR 1.18, 95% CI 0.07, 20.21). In GIM patients, apixaban compared to rivaroxaban had a numerically higher, but non-significant, rate of major bleeding (23.98 vs. 3.50 per 100 person-years; HR 4.0, 95% CI 0.54-29.87). In the overall group of CAT, the risk of major bleeding was similar between apixaban and rivaroxaban (9.51 vs. 6.77 per 100 person-years). Conclusion: In our registry of subjects with CAT, we identified a significantly increased rate of CRNMB and overall bleeding, but not MB with the use of DOACs. In our data, GIM alone does not appear to account for the increased bleeding risk seen in CAT with DOACs, as we demonstrated no significant increase in major, CRNMB, or overall bleeding compared to LMWH. Direct comparison between apixaban and rivaroxaban was limited by sample size and number of events. Disclosures No relevant conflicts of interest to declare.
Extending venous thromboembolism secondary prevention with apixaban in cancer patients: The EVE trial
AbstractBackgroundCancer‐associated venous thromboembolism (VTE) carries a high rate of recurrence and death. Guidelines recommend continued anticoagulation therapy as long as active cancer persists. Apixaban 2.5 mg twice daily is the FDA‐approved dose for secondary prevention regardless of VTE causation. Whether this apixaban dose is appropriate for secondary VTE prevention in cancer patients is not clear. The rationale and design of this investigator initiated phase III, multicenter, randomized, double‐blind, trial assessing apixaban 2.5 mg vs 5 mg twice daily for 12 months for the secondary VTE prevention in cancer patients (n = 370) who have completed 6 months (but no more than 12 months) of anticoagulation is provided (NCT03080883).Methods/DesignThe primary study objective is to estimate differences in the combined rate of major plus clinically relevant non‐major bleeding for apixaban 2.5 mg vs 5 mg twice daily. Secondary efficacy outcome is to assess rates of venous or arterial thromboembolism. Participating centers are chosen from the Academic and Community Cancer Research United (ACCRU) consortium.ConclusionWe anticipate these trial results to provide evidence supporting low‐dose apixaban as a safe agent for secondary prevention of cancer‐associated VTE for patients who have already completed 6‐12 months of anticoagulation.
416 Esophageal Body Dysfunction in Patients With Esophagogastric Junction Outflow Obstruction: A Potential Flaw in the Chicago Classification
INTRODUCTION: High-resolution manometry using the Chicago Classification is standard in the evaluation of esophageal motility. When the relaxation of the esophagogastric junction is impaired and achalasia excluded, esophagogastric junction outflow obstruction (EGJ-OO) is diagnosed and the esophageal body is essentially ignored. We sought to characterize the function of the esophageal body in consecutive patients with EGJ-OO. METHODS: Retrospective review of the esophageal manometry findings in consecutive patients where there was computer recognition of EGJ-OO collected over a 2-month period. In each case, the esophageal body was reviewed manually and results reported independent of the suggested computer diagnosis. RESULTS: 116 patients underwent manometry over a 2-month period and 30 (26%) were identified as having EGJ-OO. The indications for testing included chronic cough (n = 5), GERD (n = 8), dysphagia (n = 9) and esophageal evaluation associated with severe lung disease or transplantation (n = 8). The mean IRP was 20.8 (range 16-33.6) and did not vary depending on indication ( P = 0.381). Computer interpretation was EGJ-OO in all patients without mention of the esophageal body. After review, 11 (37%) had an additional esophageal diagnosis. In effective esophageal motility (IEM) was the most prevalent among them (IEM-8, achalasia-2, jackhammer esophagus-1; P = 0.020). The frequency of an additional esophageal diagnosis was significantly different between GERD (0%) and dysphagia (66%; P = 0.004), but not between other groups (i.e. 40% in cough and 37.5% in transplant group). An esophageal body diagnosis was significantly more likely in patients with IRP > 25 (80%) compared with those with IRP < 25 (28%; P = 0.028). CONCLUSION: 1-EGJ-OO is common in patients referred for esophageal manometry. 2-An additional esophageal body diagnosis is common in those with EGJ-OO.3-Esophageal diagnoses are more common in patients with dysphagia and in those with a very high IRP. The body of the esophagus is important in cases of EGJ-OO and should be reported independent of the computer-generated interpretation of the Chicago Classification.
Comparison of apixaban to rivaroxaban and enoxaparin in acute cancer‐associated venous thromboembolism
Abstract To provide direct comparison between apixaban and rivaroxaban in patients with acute cancer‐associated venous thromboembolism (Ca‐VTE), consecutive patients treated with apixaban, rivaroxaban, or enoxaparin at Mayo Thrombophilia Clinic (March 1, 2013 to January 31, 2018)) were followed prospectively. The primary effectiveness outcome was venous thromboembolism (VTE) recurrence, and the secondary was mortality. The primary safety outcome was major bleeding, the secondary clinically relevant safety outcome was non‐major bleeding (CRNMB), and the third a composite of major and CRNMB. There were 750 patients treated for acute Ca‐VTE with apixaban (n = 224), rivaroxaban (n = 163), and enoxaparin (n = 363) within 14 days of diagnosis and for at least 3 months, or until study event. Recurrent VTE was diagnosed in 11 receiving apixaban, 7 receiving rivaroxaban (apixaban vs rivaroxaban hazard ratio (HR) 1.31, 95% confidence interval (95% CI) 0.51‐3.36) and 17 in the enoxaparin receiving group (apixaban vs enoxaparin HR 1.14, 95% CI: 0.54, 2.42 and rivaroxaban vs enoxaparin HR 0.85, 95% Cl: 0.36, 2.06). There were 82 deaths in apixaban, 74 rivaroxaban (apixaban vs rivaroxaban HR 1.67, 95% Cl: 1.20, 2.33) and 171 in enoxaparin group (rivaroxaban vs enoxaparin HR 0.73, 95% Cl: 0.56, 0.96). Major bleeding occurred in 11 apixaban, 12 rivaroxaban (apixaban vs rivaroxaban HR 0.73, 95% Cl: 0.32, 1.66) and 21 enoxaparin group (apixaban vs enoxaparin HR 0.89, 95% Cl: 0.43, 1.84 and rivaroxaban vs enoxaparin HR 1.23, 95% Cl: 0.61, 2.50). The CRNMB rate was higher in rivaroxaban compared to apixaban ( P = .03) and LMWH ( P = .01) groups. Recurrence of VTE and major bleeding were similar in apixaban, rivaroxaban, and enoxaparin groups. Rivaroxaban was associated with higher CRNMB but lower mortality compared to apixaban and enoxaparin.