Faculty Bibliography

OBJECTIVES: Renal dysfunction is associated with increased risk of cardiovascular disease and is an independent predictor of stroke and systemic embolism. Nonvalvular atrial fibrillation (NVAF) patients with renal dysfunction may face a particularly high risk of thromboembolism and bleeding. The current retrospective cohort study was designed to assess the impact of renal function on ischemic stroke and major bleeding rates in NVAF patients in the real-world setting (outside a clinical trial). METHODS: Medical claims and Electronic Health Records were retrieved retrospectively from Optum's Integrated Claims-Clinical de-identified dataset from May 2011 to August 2014. Patients with NVAF treated with warfarin (2468) or rivaroxaban (1290) were selected. Each treatment cohort was stratified by baseline estimated creatinine clearance (eCrCl) levels. Confounding adjustments were made using inverse probability of treatment weights (IPTWs). Incidence rates and hazard ratios of ischemic stroke and major bleeding events were calculated for both cohorts. RESULTS: Overall, patients treated with rivaroxaban had an ischemic stroke incidence rate of 1.9 per 100 person-years (PY) while patients treated with warfarin had a rate of 4.2 per 100 PY (HR = 0.41 [0.21-0.80], p = .009). Rivaroxaban patients with an eCrCl below 50 mL/min (N = 229) had an ischemic stroke rate of 0.8 per 100 PY, while the rate for the warfarin cohort (N = 647) was 6.0 per 100 PY (HR = 0.09 [0.01-0.72], p = .02). For the other renal function levels (i.e. eCrCl 50-80 and >/=80 mL/min) HRs indicated no statistically significant differences in ischemic stroke risks. Bleeding events did not differ significantly between cohorts stratified by renal function. CONCLUSIONS: Ischemic stroke rates were significantly lower in the overall NVAF population for rivaroxaban vs. warfarin users, including patients with eCrCl below 50 mL/min. For all renal function groups, major bleeding risks were not statistically different between treatment groups.

PURPOSE: The EINSTEIN-Extension trial showed that an extended rivaroxaban treatment significantly reduced the risk for venous thromboembolic (VTE) recurrence. The present study assessed the risk for VTE recurrence and major bleeding associated with extended rivaroxaban treatment in a clinical practice setting among patients with VTE. METHODS: A retrospective study was conducted using claims data from February 2011 to April 2015. It included adult patients who initiated rivaroxaban therapy within 7 days after their first VTE and who continuously used rivaroxaban for at least 3 months (index date: end of initial 3-month treatment). Categorized into discontinued and continued cohorts, patients were followed up from the index date until the end of continuous treatment (continued cohort) or end of data or reinitiation of oral anticoagulant therapy (discontinued cohort). Using inverse probability of treatment weights controlling for confounders, adjusted Kaplan-Meier rates of recurrent VTE and major bleeding events were compared. FINDINGS: The analysis showed that, compared with the discontinued cohort (n = 1,536), the continued cohort (n = 5,933) had a significantly lower VTE recurrence rate after an additional 3 months (0.70% vs 1.70%), 6 months (1.41% vs 2.34%), 9 months (1.82% vs 3.01%), and 12 months (1.97% vs 3.01%) of treatment (all, p < 0.05). The difference in the cumulative event rates for major bleeding was not statistically significant. Similar results were obtained in an analysis among patients with VTE receiving rivaroxaban for >/=6 months. IMPLICATIONS: Our results suggest that, in clinical practice settings, patients with VTE who continued rivaroxaban therapy after the initial 3- or 6-month treatment period had a significantly lower risk for VTE recurrence without a statistically significant increased risk for major bleeding.

Danish nationwide registries were used to investigate temporal trends in initiation of rivaroxaban or apixaban or dabigatran versus vitamin K antagonists (VKA) in patients with venous thromboembolism (VTE). Patients treated with one of the NOACs (rivaroxaban, dabigatran, apixaban) or VKA were identified between February 2012 and September 2016. A total of 19,578 patients were included of which 10,844 (55.4%) were treated with VKA and 8,734 (44.6%) were treated with NOACs (rivaroxaban 7,572, apixaban 1,066, and dabigatran 96). Temporal trends showed a decrease in the initiation of VKA (p-value for decreasing trend, p < 0001) and an increase in the initiation of rivaroxaban and apixaban (p-value for increasing trend, p < 0001). By September 2016, 12%, 70%, 16%, and 2% of patients with VTE were initiated on VKA, rivaroxaban, apixaban, and dabigatran. Patients with previous VTE, chronic kidney disease, liver disease, cancer, and thrombophilia were more likely to be initiated on VKA compared with one of the NOACs. In conclusion the initiation of rivaroxaban and apixaban is increasing significantly over time in patients with VTE. Patients with previous VTE, chronic kidney disease, liver disease, cancer, and thrombophilia were more likely to be initiated on VKA compared with rivaroxaban or apixaban.

Background: Acute myocardial infarction (AMI) is a significant cardiovascular complication following non-cardiac surgery. We evaluated national trends in perioperative AMI, management, and outcomes using a large administrative database of United States hospital admissions. Methods: Patients who underwent non-cardiac surgery from 2005 to 2013 were identified using the National Inpatient Sample. Perioperative AMI was evaluated over time. Propensity score matching was used to compile cohorts of patients with perioperative AMI matched on their baseline characteristics who were managed invasively (defined as cardiac catheterization, percutaneous coronary intervention [PCI], or coronary artery bypass graft surgery [CABG]) versus conservatively. The primary outcome was in-hospital all-cause mortality. Results: Among 9,566,277 hospitalizations for major non-cardiac surgery, perioperative AMI occurred in 84,093 (0.88%). Over time, the rate of perioperative AMI per 100,000 surgeries declined by 170 (95% CI 158 - 181), from 898 in 2005 to 729 in 2013 (p for trend <0.0001). Perioperative AMI occurred most frequently in patients undergoing vascular (2.0%), transplant (1.6%), and thoracic (1.5%) surgery. In-hospital mortality was higher in patients with perioperative AMI than those without AMI (18.0% vs. 1.5%, p<0.0001; adjusted OR 5.76, 95% CI 5.65 - 5.88). Mortality associated with perioperative AMI declined over time (adjusted OR 0.86, 95% CI 0.84 - 0.88). In a propensity-matched cohort of 34,650 patients with perioperative AMI, invasive management was associated with lower mortality than conservative management (8.9% vs. 18.1%, p<0.001; OR 0.44, 95% CI 0.41-0.47). Conclusion: Perioperative AMI occurs in 0.9% of patients undergoing major non-cardiac surgery and is strongly associated with in-hospital mortality. Invasive management of such patients may mitigate some of this excess risk

Platelets play a critical role in atherogenesis and thrombosis-mediated myocardial ischemia, processes that are accelerated in diabetes. Whether hyperglycemia promotes platelet production and whether enhanced platelet production contributes to enhanced atherothrombosis remains unknown. Here we found that in response to hyperglycemia, neutrophil-derived S100 calcium-binding proteins A8/A9 (S100A8/A9) interact with the receptor for advanced glycation end products (RAGE) on hepatic Kupffer cells, resulting in increased production of IL-6, a pleiotropic cytokine that is implicated in inflammatory thrombocytosis. IL-6 acts on hepatocytes to enhance the production of thrombopoietin, which in turn interacts with its cognate receptor c-MPL on megakaryocytes and bone marrow progenitor cells to promote their expansion and proliferation, resulting in reticulated thrombocytosis. Lowering blood glucose using a sodium-glucose cotransporter 2 inhibitor (dapagliflozin), depleting neutrophils or Kupffer cells, or inhibiting S100A8/A9 binding to RAGE (using paquinimod), all reduced diabetes-induced thrombocytosis. Inhibiting S100A8/A9 also decreased atherogenesis in diabetic mice. Finally, we found that patients with type 2 diabetes have reticulated thrombocytosis that correlates with glycated hemoglobin as well as increased plasma S100A8/A9 levels. These studies provide insights into the mechanisms that regulate platelet production and may aid in the development of strategies to improve on current antiplatelet therapies and to reduce cardiovascular disease risk in diabetes.

OBJECTIVE: Although fruit and vegetable (F&V) consumption is associated with lower risk of coronary heart disease and stroke, its association with peripheral artery disease (PAD) is less certain. We, thus, sought to characterize F&V intake and investigate the association between F&V consumption and presence of PAD in a large community sample. APPROACH AND RESULTS: Self-referred participants at >20 000 US sites who completed medical and lifestyle questionnaires were evaluated by screening ankle brachial indices for PAD (ankle brachial index /=3 servings of F&V was reported by 29.2%. Increasing age, female sex, white race, never smoking, being currently married, physical activity, increasing income, and frequent consumption of fish, nuts, and red meat were positively associated with daily consumption of F&V. After multivariable adjustment, there was a stepwise inverse association between F&V intake and PAD. Participants reporting daily intake of >/=3 servings of F&V had 18% lower odds of PAD than those reporting less than monthly consumption. In unadjusted and multivariable-adjusted models, the inverse association with F&V became stronger as ankle brachial index decreased. When stratified by smoking status, the association was present only among those subjects who currently or formerly smoked tobacco. CONCLUSIONS: Our study demonstrates an inverse association of F&V consumption with prevalent PAD and overall low F&V consumption. These observations suggest the need to further efforts to increase F&V consumption and for more rigorous evaluation of the role of F&V in PAD prevention. VISUAL OVERVIEW: An online visual overview is available for this article.

BACKGROUND: Immune activation persists despite suppressive antiretroviral therapy (ART) in human immunodeficiency virus (HIV) infection and predicts non-Acquired Immune Deficiency Syndrome (AIDS) comorbidities including cardiovascular disease. Activated platelets play a key role in atherothrombosis and inflammation, and platelets are hyperactivated in chronic HIV infection. Aspirin is a potent inhibitor of platelet activation through the cyclooxygenase-1 (COX-1) pathway. We hypothesized that platelet activation contributes to immune activation and that aspirin would reduce immune activation and improve endothelial function in ART-suppressed HIV-infected individuals. METHODS: In this prospective, double-blind, randomized, placebo-controlled 3-arm trial of 121 HIV-infected participants on suppressive ART for >48 weeks, we evaluated the effects of 12 weeks of daily aspirin 100 mg, aspirin 300 mg, or placebo on soluble and cellular immune activation markers, flow-mediated dilation (FMD) of the brachial artery, and serum thromboxane B2, a direct readout of platelet COX-1 inhibition. RESULTS: The 300-mg and 100-mg aspirin arms did not differ from placebo in effects on soluble CD14, interleukin (IL)-6, soluble CD163, D-dimer, T-cell or monocyte activation, or the other immunologic endpoints measured. Endothelial function, as measured by FMD, also was not significantly changed when comparing the 300-mg and 100-mg aspirin arms to placebo. CONCLUSIONS: Aspirin treatment for 12 weeks does not have a major impact on soluble CD14, IL-6, soluble CD163, D-dimer, T-cell or monocyte activation, or FMD, suggesting that inhibition of COX-1-mediated platelet activation does not significantly improve HIV-related immune activation and endothelial dysfunction. Although future studies are needed to further identify the causes and consequences of platelet activation in ART-treated HIV infection, interventions other than COX-1 inhibition will need to be explored to directly reduce immune activation in treated HIV infection.

Von Willebrand disease (VWD) is an inherited bleeding disorder that often manifests clinically with hemorrhage after invasive procedures. We investigated the association between a diagnosis of VWD and bleeding and thrombotic outcomes following major non-cardiac surgery in a large national database from the United States. Patients age >/=45 years requiring major non-cardiac surgery were identified from Healthcare Cost and Utilization Project's National Inpatient Sample data. Von Willebrand disease, perioperative major adverse cardiovascular events (MACE), thrombotic events, and hemorrhage were defined by ICD9 diagnosis codes. From 2004 to 2013, a total of 10,581,621 hospitalizations for major non-cardiac surgery met study inclusion criteria and VWD was identified in 3765 (0.036%). In adjusted analyses, patients with VWD were significantly more likely to develop post-operative hemorrhage than patients without VWD (5.5 vs. 1.9%, p < 0.001; adjusted OR 3.49, 95% CI 3.03-4.03), but had similar odds of perioperative MACE and thrombotic events. Thus, a diagnosis of VWD was associated with increased risks of bleeding with non-cardiac surgery, without a corresponding reduction in perioperative thrombosis in comparison to patients without VWD. Perioperative management of patients with hereditary bleeding disorders and mitigation of thrombotic risks requires further study.

BACKGROUND: Little is known about patterns of medication use and lifestyle counseling in patients with peripheral artery disease (PAD) in the United States. OBJECTIVES: The authors sought to evaluate trends in both medical therapy and lifestyle counseling for PAD patients in the United States from 2005 through 2012. METHODS: Data from 1,982 outpatient visits among patients with PAD were obtained from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey, a nationally representative assessment of office-based and hospital outpatient department practice. Trends in the proportion of visits with medication use (antiplatelet therapy, statins, angiotensin-converting enzyme inhibitors [ACEIs] or angiotensin receptor blockers [ARBs], and cilostazol) and lifestyle counseling (exercise or diet counseling and smoking cessation) were evaluated. RESULTS: Over the 8-year period, the average annual number of ambulatory visits in the United States for PAD was 3,883,665. Across all visits, mean age was 69.2 years, 51.8% were female, and 56.6% were non-Hispanic white. Comorbid coronary artery disease (CAD) was present in 24.3% of visits. Medication use for cardiovascular prevention and symptoms of claudication was low: any antiplatelet therapy in 35.7% (standard error [SE]: 2.7%), statin in 33.1% (SE: 2.4%), ACEI/ARB in 28.4% (SE: 2.0%), and cilostazol in 4.7% (SE: 1.0%) of visits. Exercise or diet counseling was used in 22% (SE: 2.3%) of visits. Among current smokers with PAD, smoking cessation counseling or medication was used in 35.8% (SE: 4.6%) of visits. There was no significant change in medication use or lifestyle counseling over time. Compared with visits for patients with PAD alone, comorbid PAD and CAD were more likely to be prescribed antiplatelet therapy (odds ratio [OR]: 2.6; 95% confidence interval [CI]: 1.8 to 3.9), statins (OR: 2.6; 95% CI: 1.8 to 3.9), ACEI/ARB (OR: 2.6; 95% CI: 1.8 to 3.9), and smoking cessation counseling (OR: 4.4; 95% CI: 2.0 to 9.6). CONCLUSIONS: The use of guideline-recommended therapies in patients with PAD was much lower than expected, which highlights an opportunity to improve the quality of care in these high-risk patients.

OBJECTIVE: Low to moderate inorganic arsenic (iAs) exposure is independently associated with cardiovascular disease (CVD), particularly for patients with diabetes mellitus (DM). The mechanism of increased CVD risk from iAs exposure in DM has not been adequately characterized. We evaluated whether increasing concentrations of glucose enhance the effects of iAs on platelet and megakaryocyte activity, key steps in atherothrombosis. METHODS: Healthy donor whole blood was prepared in a standard fashion and incubated with sodium arsenite in a range from 0 to 10 microM. iAs-induced platelet activation was assessed by platelet receptor CD62P (P-selectin) expression and monocyte-platelet and leukocyte-platelet aggregation (MPA and LPA, respectively) in the presence of increasing sodium arsenite and glucose concentrations. Megakaryocyte (Meg-01) cell adhesion and gene expression was assessed after incubation with or without iAs and increasing concentrations of D-glucose. RESULTS: Platelet activity markers increased significantly with 10 vs. 0 microM iAs (P < 0.05 for all) and with higher D-glucose concentrations. Platelet activity increased significantly following co incubation of 1 and 5 microM iAs concentrations with hyperglycemic D-glucose (P < 0.01 for both) but not after incubation with euglycemic D-glucose. Megakaryocyte adhesion was more pronounced after co incubation with iAs and hyperglycemic than euglycemic D-glucose, while gene expression increased significantly to iAs only after co incubation with hyperglycemic D-glucose. CONCLUSION: We demonstrate that glucose concentrations common in DM potentiate the effect of inorganic arsenic exposure on markers of platelet and megakaryocyte activity. Our results support recent observational cohort data that DM enhances the vasculotoxic effects of arsenic exposure, and suggest that activation of the platelet-megakaryocyte hemostatic axis is a pathway through which inorganic arsenic confers atherothrombotic risk, particularly for patients with DM.