Response to clopidogrel in patients undergoing lower extremity revascularization

OBJECTIVES

Clopidogrel is effective at decreasing cardiovascular events in patients with peripheral artery disease (PAD); however, its effect on limb outcomes are less known. This study investigated the variability in response to clopidogrel and its relationship with clinical limb outcomes.

METHODS

Three hundred subjects were enrolled in the Platelet Activity and Cardiovascular Events (PACE) study prior to lower extremity revascularization, of whom 104 were on clopidogrel. Light transmission platelet aggregation was measured in response to ADP 2 μ m immediately prior to revascularization. Patients were followed longitudinally for a median follow-up of 18 months. The primary endpoint was major adverse limb events (MALE) defined by major amputation or reoperation of the affected limb. Patients were stratified into groups according to percent ADP-induced aggregation. Poor response to clopidogrel was defined by >50% aggregation.

RESULTS

Overall, the median age was 70 (63, 76) and 35.6% were female. Twenty-nine (27.9%) patients experienced MALE during their follow-up. Median aggregation to ADP 2 μ m was 22.5% (Q1-Q3: 10%, 50%) and 27 subjects (26%) were clopidogrel poor responders. Baseline aggregation was higher in subjects who went on to develop a MALE than those without MALE (43% vs 20%, p = .017). Subjects with aggregation > median (22.5%) were more likely to experience MALE than aggregation < median (38.5% vs 17.3%, p = .029). After multivariable adjustment for age, sex, race/ethnicity, BMI, diabetes, coronary artery disease, and aspirin use, aggregation > median was associated with MALE (adjusted HR [aHR] 2.67, 95% CI 1.18-6.01, p = .018). When stratified by established cut-offs for responsiveness to clopidogrel (50% aggregation), poor responders were more likely to experience MALE than normal responders (44.4% vs 22.1%, aHR 2.18, 95% CI 1.00-4.78, p = .051).

CONCLUSIONS

Among patients undergoing lower extremity revascularization on clopidogrel, higher baseline percent aggregation is associated with increased risk for major adverse limb events.

Surgical resection of lumbar intradural metastatic renal cell carcinoma

A 60-year-old male with renal cell carcinoma (RCC) presented with back pain, weakness, and bowel and bladder urgency. MRI demonstrated a cauda equina tumor at L2. Following L1-3 laminectomies, intraoperative ultrasound localized the tumor. After dural opening, a vascular tumor was adherent to the cauda equina. Intraoperative nerve stimulation helped to identify the nerve rootlets. Tumor was removed in a piecemeal fashion. Tumor dissection caused periodic spasms in L1-3 distributions. A neuromonitoring checklist was used to recover motor evoked potential signals with elevated mean arterial pressures. Hemostasis was challenging with the vascular tumor. Intraoperative ultrasound confirmed tumor debulking. Pathology confirmed metastatic RCC.

QOL-17. UNDERSTANDING MULTIDISCIPLINARY PROVIDER PERSPECTIVES AND PREFERENCES FOR INCORPORATING EXERCISE INTO PRIMARY BRAIN TUMOR MANAGEMENT

BACKGROUND

Exercise has proven benefit in patients with cancer with most studies focused on patients with high functional and neurocognitive status. Patients with brain tumors, however, frequently have deficits in cognition, motor, balance, or other symptoms that are further exacerbated by surgery and adjuvant treatment. We sought to determine providers’ knowledge, attitudes, motivating factors and preferences for integrating exercise into the treatment of patients with brain tumors.

METHODS

We surveyed multidisciplinary providers in Neurosurgery, Radiation Oncology and Neuro-Oncology from a single, quaternary medical center. Questions assessed demographics, current practices, attitudes, knowledge, motivating factors and barriers for integrating exercise into treatment. Questions were extrapolated from existing published questionnaires and sent electronically.

RESULTS

Most providers (92%) reported that exercise was important for patients' lifestyle and 80% felt it should be integrated into the treatment of patients with primary brain tumors. Nighty-six percent felt that exercise improved quality of life, decreased fatigue (100%) and reduced treatment related side effects (92%) yet only 57% of providers initiated a conversation about exercise with patients. Top motivating factors for promoting exercise were perceived benefit to patients’ quality of life and disease outcomes. Barriers to provider/patient discussions about exercise included, lack of time or appropriate expertise to discuss exercise with patients, and concern that patients have competing priorities. Some providers (23%) were concerned about potential limitations/complications with patients exercising including inability to participate from side effects of treatment (38%), physical deficits (61%) and fatigue (42%).

CONCLUSION

Understanding barriers for providers to incorporate exercise into their patients’ treatment regimens is critical to strategizing best practices. Findings from this study help to expand our understanding of barriers and facilitators to incorporating exercise interventions into brain cancer treatment and will assist with the implementation of a structured exercise program to enhance physical health for our patients.

Statin therapy upregulates arachidonic acid status via enhanced endogenous synthesis in patients with plaque psoriasis

Circulating fatty acids (FA) may be important in the psoriatic pro-inflammatory phenotype. FADS1 converts linoleic acid (LA) to arachidonic acid (AA), a precursor to potent signaling molecules. HMG-CoA reductase inhibitors (statins) increase FADS1/2 expression in vitro. Psoriasis patients (42 ± 14 years/age, 47% male) were randomized to 40 mg of atorvastatin (n = 20) or nothing (n = 10) for two weeks and plasma FA measured pre and post treatment. After treatment, LDL-C was 44% lower in the statin compared to the no-treatment group. Statins increased FADS1/2 expression, and lowered LA 12% (33% - > 29%, p<0.001) and raised AA 14% (7.7% - > 9.0%, p<0.01) with no change in the no-treatment group. In psoriasis, statins enhance AA and decrease LA, consistent with the action of enhanced FADS expression in vivo. Therapies intended to blunt the effects of AA on platelet aggregation, such as aspirin or omega-3 fatty acids, may require dose adjustment when co-administered with atorvastatin. NCT: NCT03228017.

Competition in California’s Medi-Cal Managed Care Market Assessed by Herfindahl-Hirschman Index

Evaluating market competition is an important practice to assess how the forces and components at play in a select market interact. Healthcare markets are similar to any other market present in the world, where competition can be present or absent in the exchange of goods and services. Applying a standard measure of assessing market competition, the Herfindahl-Hirschman Index, to California’s Medi-Cal managed care marketplace, it is found that there is no competition present in all of California’s counties as defined by the common interpretation of the Herfindahl-Hirschman Index. A distinctive trend in markets is that when less competition is present, the cost of goods and services increases to reflect the principles of supply and demand. California Medi-Cal markets follow this trend of less competitive markets being associated with increased adult midpoint costs. These findings help further to elucidate California’s Medi-Cal marketplace on a county-by county level.

Platelets amplify endotheliopathy in COVID-19

Given the evidence for a hyperactive platelet phenotype in COVID-19, we investigated effector cell properties of COVID-19 platelets on endothelial cells (ECs). Integration of EC and platelet RNA sequencing revealed that platelet-released factors in COVID-19 promote an inflammatory hypercoagulable endotheliopathy. We identified S100A8 and S100A9 as transcripts enriched in COVID-19 platelets and were induced by megakaryocyte infection with SARS-CoV-2. Consistent with increased gene expression, the heterodimer protein product of S100A8/A9, myeloid-related protein (MRP) 8/14, was released to a greater extent by platelets from COVID-19 patients relative to controls. We demonstrate that platelet-derived MRP8/14 activates ECs, promotes an inflammatory hypercoagulable phenotype, and is a significant contributor to poor clinical outcomes in COVID-19 patients. Last, we present evidence that targeting platelet P2Y12 represents a promising candidate to reduce proinflammatory platelet-endothelial interactions. Together, these findings demonstrate a previously unappreciated role for platelets and their activation-induced endotheliopathy in COVID-19.

Abstract 109: Platelets Amplify Endotheliopathy In Covid-19

In addition to their pivotal role in thrombosis and hemostasis, platelets participate in inflammatory responses and endothelial cell activation - hallmarks in the pathogenesis of coronavirus disease 2019 (COVID-19). Given the evidence for a hyperactive platelet phenotype in COVID-19, we investigated effector cell properties of COVID-19 platelets on endothelial cells (ECs). To explore this interaction, ECs were treated with platelet releasate from patients with and without COVID-19, and EC mRNA sequencing performed. We demonstrate that platelet released factors in COVID-19 promote an inflammatory hypercoagulable endotheliopathy. Investigation of the COVID-19 platelet transcriptome identified pathways related to organelle/granule release, metabolism, and immune effector function in addition to upregulation of S100A8 and S100A9 mRNA. Incubation of primary megakaryocytes with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) also induced upregulation of S100A8 and S100A9 mRNA. Consistent with increased gene expression, the heterodimer protein product of S100A8 / A9 , myeloid-related protein (MRP)8/14, was released to a greater extent by platelets from COVID-19 patients relative to controls. We demonstrate that platelet-derived MRP8/14 activates microvascular endothelial cells, promotes an inflammatory hypercoagulable phenotype, and is a significant contributor to thromboinflammation and poor clinical outcomes in COVID-19 patients. Finally, we present evidence that therapeutic targeting of platelet P2Y 12 represents a promising candidate to reduce proinflammatory and prothrombotic platelet-endothelial interactions. Altogether, these findings demonstrate a previously unappreciated role for platelets and their activation-induced endotheliopathy in COVID-19.

Reshaping of the gastrointestinal microbiome alters atherosclerotic plaque inflammation resolution in mice

Since alterations in the intestinal microbiota may induce systemic inflammation and polarization of macrophages to the M1 state, the microbiome role in atherosclerosis, an M1-driven disease, requires evaluation. We aimed to determine if antibiotic (Abx) induced alterations to the intestinal microbiota interferes with atherosclerotic plaque inflammation resolution after lipid-lowering in mice. Hyperlipidemic Apoe^−/− mice were fed a western diet to develop aortic atherosclerosis with aortas then transplanted into normolipidemic wild-type (WT) mice to model clinically aggressive lipid management and promote atherosclerosis inflammation resolution. Gut microbial composition pre and post-transplant was altered via an enteral antibiotic or not. Post aortic transplant, after Abx treatment, while plaque size did not differ, compared to Apoe^−/− mice, Abx^– WT recipient mice had a 32% reduction in CD68-expressing cells (p = 0.02) vs. a non-significant 12% reduction in Abx⁺ WT mice. A trend toward an M1 plaque CD68-expresing cell phenotype was noted in Abx⁺ mice. By 16S rRNA sequence analysis, the Abx⁺ mice had reduced alpha diversity and increased Firmicutes/Bacteroidetes relative abundance ratio with a correlation between gut Firmicutes abundance and plaque CD68-expressing cell content (p < 0.05). These results indicate that in a murine atherosclerotic plaque inflammation resolution model, antibiotic-induced microbiome perturbation may blunt the effectiveness of lipid-lowering to reduce the content of plaque inflammatory CD68-expressing cells.

CCL20 in psoriasis: A potential biomarker of disease severity, inflammation, and impaired vascular health

BACKGROUND

Psoriasis is associated with increased cardiovascular risk that is not captured by traditional proinflammatory biomarkers.

OBJECTIVE

To investigate the relationship between Psoriasis Area and Severity Index, circulating proinflammatory biomarkers, and vascular health in psoriasis.

METHODS

In patients with psoriasis and in age and sex-matched controls, 273 proteins were analyzed with the Proseek Multiplex Cardiovascular disease reagents kit and Inflammatory reagents kit (Olink Bioscience), whereas vascular endothelial inflammation and health were measured via direct transcriptomic analysis of brachial vein endothelial cells.

RESULTS

In psoriasis, chemokine ligand 20 (CCL20), interleukin (IL) 6, and IL-17A were the top 3 circulating proinflammatory cytokines. Vascular endothelial inflammation correlated with CCL20 (r = 0.55; P < .001) and less so with IL-6 (r = 0.36; P = .04) and IL-17A (r = 0.29; P = .12). After adjustment for potential confounders, the association between CCL20 and vascular endothelial inflammation remained significant (β = 1.71; P = .02). In nested models, CCL20 added value (χ² = 79.22; P < .001) to a model already incorporating the Psoriasis Area and Severity Index, Framingham risk, high-sensitivity C-reactive protein, Il-17A, and IL-6 (χ² = 48.18; P < .001) in predicting vascular endothelial inflammation.

LIMITATIONS

Our study was observational and did not allow for causal inference in the relationship between CCL20 and cardiovascular risk.

CONCLUSION

We demonstrate that CCL20 expression has a strong association with vascular endothelial inflammation, reflects systemic inflammation, and may serve as a potential biomarker of impaired vascular health in psoriasis.

Characterization of PCSK9 in the Blood and Skin of Psoriasis

Mechanisms explaining the link between psoriasis, a proinflammatory condition, and cardiovascular disease are not fully known. PCSK9 is predominantly expressed in hepatocytes as a critical regulator of lipid metabolism, and clinical trials targeting PCSK9 reduce cardiovascular disease. Independent of its role in lipid metabolism, PCSK9 levels associate with endothelial dysfunction and predict cardiovascular events. We used two separate human psoriasis cohorts and the K14-Rac1V12^-/+ murine model of psoriasis to investigate PCSK9 and cardiovascular risk in psoriasis. In both psoriasis cohorts (n = 88 and n = 20), PCSK9 levels were 20% and 13% higher than in age-, sex-, and cholesterol-matched controls, respectively (P < 0.05 for each comparison) and correlated with PASI (r = 0.43, P < 0.05). Despite no difference in hepatocyte expression, K14-Rac1V12^-/+ mice demonstrated skin-specific PCSK9 staining, which was confirmed in human psoriatic lesional skin. In patients with psoriasis, PCSK9 levels correlated with impaired endothelial vascular health (e.g., early atherosclerosis, β = 4.5, P < 0.01) and log converted coronary artery calcium score (β = 0.30, P = 0.01), which remained significant after adjustment for Framingham risk, body mass index, and active biologic use. Taken together, these findings suggest, independent of cholesterol, an association between circulating PCSK9 and early as well as advanced stages of atherosclerosis in psoriasis.

Activated Platelets Induce Endothelial Cell Inflammatory Response in Psoriasis via COX-1

OBJECTIVE

Patients with psoriasis have impaired vascular health and increased cardiovascular disease (CVD). Platelets are key players in the pathogenesis of vascular dysfunction in cardiovascular disease and represent therapeutic targets in cardiovascular prevention. The object of this study was to define the platelet phenotype and effector cell properties on vascular health in psoriasis and evaluate whether aspirin modulates the platelet-induced phenotype. Approach and Results: Platelets from psoriasis patients (n=45) exhibited increased platelet activation (relative to age- and gender-matched controls, n=18), which correlated with psoriasis skin severity. Isolated platelets from psoriasis patients demonstrated a 2- to 3-fold (P<0.01) increased adhesion to human aortic endothelial cells and induced proinflammatory transcriptional changes, including upregulation of IL 8 (interleukin 8), IL1β, and Cox (cyclooxygenase)-2 Platelet RNA sequencing revealed an interferon signature and elevated expression of COX-1, which correlated with psoriasis disease severity (r=0.83, P=0.01). In a randomized trial of patients with psoriasis, 2 weeks of 81 mg low-dose aspirin, a COX-1 inhibitor, reduced serum thromboxane (Tx) B2 and reduced brachial vein endothelial proinflammatory transcript expression >70% compared with the no-treatment group (P<0.01). Improvement in brachial vein endothelial cell inflammation significantly correlated with change in serum TxB2 (r=0.48, P=0.02).

CONCLUSIONS

In patients with psoriasis, platelets are activated and induce endothelial cell inflammation. Low-dose aspirin improved endothelial cell health in psoriasis via platelet COX-1 inhibition. These data demonstrate a previously unappreciated role of platelets in psoriasis and endothelial cell inflammation and suggests that aspirin may be effective in improving vascular health in patients with psoriasis. Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03228017.

Penetrating wounds of the back and flank: analysis of 77 cases

To determine the factors that allow early recognition of injuries to the intrathoracic and intra-abdominal organs in patients with penetrating wounds to the lower thorax and abdomen with site of entrance located in the back or flanks, we retrospectively analyzed the cases of 77 such patients. There were 65 stab wounds (85%) and 12 gunshot wounds (15%). The injuries were confined to the abdomen in 46 (60%); 39 were stab wounds and seven were gunshot wounds. The wounds were confined to the chest in 24 patients (31%) and involved both the chest and abdomen in seven cases (9%). Of the 53 abdominal wounds, 21 necessitated celiotomy; in 20 of them, an intra-abdominal organ was found injured, and one patient died (1.9%). Of the 24 injuries confined to the chest, only one patient required emergency thoracotomy due to massive hemorrhage; all 24 patients survived. All of the seven thoracoabdominal injuries, two produced by gunshot and five by stabbing, necessitated celiotomy. Most patients with gunshot wounds to the back and flanks require celiotomy, but a selective therapy can be safely used in patients with stab wounds. The rate of negative exploratory celiotomy was less than 5%; the mortality was 1.3%.

Effect of urban versus rural residence and of maternal education on infant health in South Lebanon

A sample of 253 women from rural and urban areas of south Lebanon were visited for 18 months after delivery. Information was collected on patterns of reproduction, infant feeding, and use of the health services. The findings indicate that educated women and women living in urban areas were better off in terms of family formation patterns, immunisation, and well-baby care. The importance of educating women, particularly in rural areas, as a policy that can be varied to improve child health and growth is thus emphasised. The study also indicates, however, the special need for health education programmes directed to all mothers to emphasise proper breast-feeding patterns and the importance of preventive health care for infants. The findings also indicate the need for a more diversified system of delivering health care in which properly trained paramedical personnel take part, particularly in rural areas.