Screening over 100 000 patients in 39 general practices in the Netherlands for anticoagulation underprescription in atrial fibrillation: a descriptive, cross-sectional study.

OBJECTIVES: To investigate the underprescription of oral anticoagulation (OAC) in individual atrial fibrillation (AF) patients in primary care. SETTING: Screening of patient records in 39 participating general practitioners (GPs) across the Netherlands. PARTICIPANTS: We screened 101 207 patient records identifying 2375 non-valvular AF patients. METHODS: Using electronic patient files, we were able to screen the entire GP population for AF, CHA2DS2-VASc stroke risk scores, and the use of guidelines recommended OAC prescription. In case of a deviation from guidelines recommended OAC prescription, we checked the electronic patient file for any documented reason. Additionally, 6 weeks following the screening, we asked all GPs to provide information on any actions taken for the underprescribed patients. RESULTS: We found a mean CHA2DS2-VASc score of 3.2. OAC prescription consisted of direct OAC in 1342/1984 (68%) and vitamin K-antagonists in the remainder of patients. OAC underprescription was present in 93/944 (9.9%) females and 101/1374 (9.7%) in males, respectively. In 111/146 (76.0%) of the underprescribed AF patients, no reason to withhold OAC was reported. Reported reasons to withhold OAC were patient refusal (n=10), cardiologist advice (n=7) and high risk of bleeding (n=7). Data regarding actions following the identification of OAC underprescription were available for 92/194 (47%) of the OAC underprescribed cases. After consultation OAC was initiated in 9/92 (10%) only. CONCLUSIONS: In this large Dutch study among GPs, we observed 9.8% underprescription of OAC in AF patients. In 76% of the AF patients lacking a prescription for OAC, no documentation for deviating from the guidelines was found. Only in a minority of cases detection of OAC underprescription lead to OAC initiation.

The relationship of a Prothrombin G20210A mutation or a factor V Leiden mutation and on-aspirin platelet (re-)activity.

INTRODUCTION: The interplay between platelets and pro-thrombotic factors may have been under-investigated in the identification of aspirin users at high risk for cardiovascular event reoccurrences. There is growing evidence that a Prothrombin G20210A (FII) or a Factor V Leiden (FVL) mutation might increase platelet activity. Subsequently, this study assessed on-aspirin platelet (re-)activity in non-pregnant participants with a FII - or a FVL mutation in comparison with non-pregnant data derived from controls. METHODS: This study was conducted with data derived from the follow-up FRUIT-RCT. This is a unique cohort namely, participants without a history of cardiovascular disease or thrombotic events, but who are a carrier of a pro-thrombotic mutation. All participants were instructed to ingest aspirin once daily for 10 days. Platelet (re-)activity was measured by the PFA Closure Time (PFA-CT), the VerifyNow (VN-ARU), and serum Thromboxane B2 (sTxB2) levels. RESULTS: In total, eight participants with a FII-, 15 with a FVL mutation, and 21 controls were included. The FII mutation carriers demonstrated significantly higher on-aspirin platelet (re)-activity (PFA-CT, -92 sec.; VN-ARU, +37 ARU) vs. controls. The FVL carriers demonstrated similar on-aspirin platelet (re-)activity vs. controls. The sTxB 2 levels were similar in either of the carrier groups vs. controls. CONCLUSION: We feel these data are suggestive of increased on-aspirin platelet (re-)activity, as measured by the PFA-200 and the VerifyNow, in non-pregnant carriers of a FII-mutation, but not in carriers of FVL-mutation. Interestingly, this increased on-aspirin platelet (re-)activity is present in spite of low sTxB2 levels.

Resistance of aspirin during and after pregnancy: A longitudinal cohort study.

OBJECTIVES: The objective of this study is to investigate possible changes in aspirin resistance during and after pregnancy over time. STUDY DESIGN: A longitudinal cohort study in obstetric high risk women with an indication for aspirin usage during pregnancy to prevent placenta mediated pregnancy complications. MAIN OUTCOME MEASURES: Aspirin resistance measured in the first, second and third trimester of pregnancy and at least three months postpartum by four complementary test: PFA-200, VerifyNow®, Chronolog light transmission aggregometry (Chronolog LTA) and serum thromboxane B2 (TxB2) level measurements. Correlation between the devices was investigated. RESULTS: In total, 23 pregnant women participated in the present study. Aspirin resistance according to the PFA-200, VerifyNow®, Chronolog LTA and serum TxB2, was 30.4%, 17.4%, 26.1% and 23.8% respectively. Resistance by any device was 69.6%. Aspirin resistance measured by the VerifyNow®, Chronolog LTA, serum TxB2 and aspirin resistance by any device during pregnancy was demonstrated more frequently than aspirin resistance after pregnancy. Correlation between the different devices was weak. CONCLUSION: Aspirin resistance was found in a considerable part of the participants. Considerable variation between participants, within participants over time and between the different devices was found. Prevalence of aspirin resistance during pregnancy differs from after pregnancy. More research on aspirin resistance and clinical obstetric outcome is needed.

Short-term LPS induces aortic valve thickening in ApoE*3Leiden mice.

BACKGROUND: Recently, it was shown that 12 weeks of lipopolysaccharide (LPS) administration to nonatherosclerotic mice induced thickening of the aortic heart valve (AV). Whether such effects may also occur even earlier is unknown. As most patients with AV stenosis also have atherosclerosis, we studied the short-term effect of LPS on the AVs in an atherosclerotic mouse model. METHODS: ApoE*3Leiden mice, on an atherogenic diet, were injected intraperitoneally with either LPS or phosphate buffered saline (PBS), and sacrificed 2 or 15 days later. AVs were assessed for size, fibrosis, glycosaminoglycans (GAGs), lipids, calcium deposits, iron deposits and inflammatory cells. RESULTS: LPS injection caused an increase in maximal leaflet thickness at 2 days (128.4 µm) compared to PBS-injected mice (67.8 µm; P = 0.007), whereas at 15 days this was not significantly different. LPS injection did not significantly affect average AV thickness on day 2 (37.8 µm), but did significantly increase average AV thickness at day 15 (41.6 µm; P = 0.038) compared to PBS-injected mice (31.7 and 32.3 µm respectively). LPS injection did not affect AV fibrosis, GAGs and lipid content. Furthermore, no calcium deposits were found. Iron deposits, indicative for valve haemorrhage, were observed in one AV of the PBS-injected group (a day 2 mouse; 9.1%) and in five AVs of the LPS-injected group (both day 2- and 15 mice; 29.4%). No significant differences in inflammatory cell infiltration were observed upon LPS injection. CONCLUSION: Short-term LPS apparently has the potential to increase AV thickening and haemorrhage. These results suggest that systemic inflammation can acutely compromise AV structure.

LPS-Induced Systemic Inflammation Does Not Alter Atherosclerotic Plaque Area or Inflammation in APOE3*LEIDEN Mice in the Early Phase Up to 15 Days.

BACKGROUND AND AIMS: Observational studies show a peak incidence in cardiovascular events during and early after clinical conditions associated with substantial systemic inflammation, such as pneumonia. The acuteness of this increased risk suggests rapid plaque destabilization and associated intraplaque inflammation. We evaluated whether lipopolysaccharides (LPS)-evoked acute systemic inflammation would induce such detrimental vascular changes in murine aortas with manifest atherosclerotic lesions. METHODS AND RESULTS: ApoE3*Leiden mice were fed a high cholesterol diet for 20 weeks to establish atherosclerosis. Thereafter, mice received a single intraperitoneal injection with LPS to induce systemic inflammation, or saline for control. Mice were sacrificed 2 or 15 days post-LPS injection (n = 17) or post-saline injection (n = 13). Serum amyloid A, a sensitive marker of systemic inflammation, increased 250-fold in LPS-treated mice. Aortic root plaques were assessed for total plaque area, plaque severity, and inflammatory cell content. No significant differences in total surface area of atherosclerotic plaque were found between control and LPS groups sacrificed after 2 days (resp. 0.409 ±â€Š0.228 × 10 µm vs. 0.285 ±â€Š0.169 × 10 µm) (P = 0.31), and 15 days (resp. 0.950 ±â€Š0.938 × 10 µm vs. 0.612 ±â€Š0.413 × 10 µm) (P = 0.80). Furthermore, plaque type and number of lesions were unaltered and intraplaque density of macrophages and lymphocytes were comparable in both the groups. CONCLUSIONS: Intraperitoneal LPS injection in ApoE3*Leiden mice triggers a profound systemic inflammatory response, but does not increase atherosclerotic plaque area or inflammatory cell density. This model of LPS-induced inflammation in atherosclerosis-prone mice argues against intraplaque alterations as an explanation for acute inflammation-induced cardiovascular event risk.

Mast cells are increased in the media of coronary lesions in patients with myocardial infarction and may favor atherosclerotic plaque instability.

OBJECTIVES: Mast cells (MCs) may play an important role in plaque destabilization and atherosclerotic coronary complications. Here, we have studied the presence of MCs in the intima and media of unstable and stable coronary lesions at different time points after myocardial infarction (MI). METHODS: Coronary arteries were obtained at autopsy from patients with acute MI (up to 5 days old; n=27) and with chronic MI (5-14 days old; n=18), as well as sections from controls without cardiac disease (n=10). Herein, tryptase-positive MCs were quantified in the intima and media of both unstable and stable atherosclerotic plaques in infarct-related and non-infarct-related coronary arteries. RESULTS: In the media of both acute and chronic MI patients, the number of MCs was significantly higher than in controls. This was also found when evaluating unstable and stable plaques separately. In patients with chronic MI, the number of MCs in unstable lesions was significantly higher than in stable lesions. This coincided with a significant increase in the relative number of unstable plaques in patients with chronic MI compared with control and acute MI. No differences in MC density were found between infarct-related and non-infarct-related coronary arteries in patients with MI. CONCLUSION: The presence of MCs in the media of both stable and unstable atherosclerotic coronary lesions after MI suggests that MCs may be involved in the onset of MI and, on the other hand, that MI triggers intra-plaque infiltration of MCs especially in unstable plaques, possibly increasing the risk of re-infarction.

Inflammatory cell content of coronary thrombi is dependent on thrombus age in patients with ST-elevation myocardial infarction.

BACKGROUND: ST-elevation myocardial infarction (STEMI) is typically caused by an occlusive coronary thrombus. The process of intracoronary thrombus formation is poorly understood. It is known that inflammatory cells play a role in the formation and resolution of venous thrombi, however their role in coronary thrombosis is not clear. We therefore analyzed inflammatory cells in thrombi derived from patients with STEMI in relation to histologically classified thrombus age. METHODS: Thrombus aspirates of 113 patients treated with primary percutaneous coronary intervention were prospectively collected and classified (fresh, lytic, or organized) based on hematoxylin and eosin staining. The density of inflammatory cells neutrophils (MPO), monocytes/macrophages (CD68), lymphocytes (CD45), and the platelet area (CD31), were visualized using immunohistochemistry. Patients' history, medication, and laboratory data were registered. RESULTS: Fresh thrombi (76.1%) were the most abundant as compared to lytic (16.8%) and organized (7.1%) thrombi. Neutrophils were significantly less present in organized (169cells/mm2) compared to fresh (327 cells/mm2) and lytic thrombi (311 cells/mm2). Monocytes/macrophages were significantly more present in lytic (471 cells/mm2) than in fresh (312 cells/mm2) thrombi. We additionally found that thrombi from patients aged <50 years as compared to >50 years old contained significantly more neutrophils and monocytes/macrophages irrespective of thrombus age. Furthermore platelet area was smaller in patients on aspirin again irrespective of thrombus age. No gender differences were found. CONCLUSIONS: The composition of inflammatory cells differs with thrombus age in thrombosuction material of STEMI patients that in part depends on patient age and medication.

Post-pregnancy aspirin resistance appears not to be related with recurrent hypertensive disorders of pregnancy.

OBJECTIVE: The FRUIT-RCT concluded that low-molecular-weight heparin added to aspirin compared to treatment with aspirin alone is beneficial in the prevention of early-onset hypertensive disorders of pregnancy (HD) in women with inheritable thrombophilia and prior HD and/or a small-for-gestational age (SGA) infant leading to delivery before 34 weeks gestation. The aim of this study is to answer the question whether aspirin resistance is associated with recurrent HD. STUDY DESIGN: Women with and without recurrent HD matched for age, study arm, and chronic hypertension were invited for this follow-up study 6-16 years after they participated in the FRUIT-RCT. Aspirin resistance was tested after 10days of aspirin intake using three complementary tests: PFA-200, VerifyNow® and serum thromboxane B2 (TXB2). An independent t-test, Mann-Whitney U test, Fisher's Exact test and Chi2 test were used for the statistical analyses. RESULTS: Thirteen of 24 women with recurrent HD and 16 of 24 women without recurrent HD participated. The prevalence of laboratory aspirin resistance was 34.5% according to the PFA-200, 3.4% according to the VerifyNow® and 24.1% according to TXB2. The prevalence of aspirin resistance by any test was 51.7%. Aspirin resistance per individual test did not differ between women with and without recurrent HD. Aspirin resistance measured by any test occurred more frequently in women without recurrent HD (p<0.01), irrespective of low-molecular-weight heparin. CONCLUSIONS: No relation could be demonstrated between recurrent HD and aspirin resistance per test, measured up to 16 years after pregnancy. On the contrary, complementary aspirin resistance measurements were encountered more frequently in women without recurrent HD.

Orthopedic surgery increases atherosclerotic lesions and necrotic core area in ApoE-/- mice.

BACKGROUND AND AIMS: Observational studies show a peak incidence of cardiovascular events after major surgery. For example, the risk of myocardial infarction increases 25-fold early after hip replacement. The acuteness of this increased risk suggests abrupt enhancement in plaque vulnerability, which may be related to intra-plaque inflammation, thinner fibrous cap and/or necrotic core expansion. We hypothesized that acute systemic inflammation following major orthopedic surgery induces such changes. METHODS: ApoE-/- mice were fed a western diet for 10 weeks. Thereafter, half the mice underwent mid-shaft femur osteotomy followed by realignment with an intramedullary K-wire, to mimic major orthopedic surgery. Mice were sacrificed 5 or 15 days post-surgery (n = 22) or post-saline injection (n = 13). Serum amyloid A (SAA) was measured as a marker of systemic inflammation. Paraffin embedded slides of the aortic root were stained to measure total plaque area and to quantify fibrosis, calcification, necrotic core, and inflammatory cells. RESULTS: Surgery mice showed a pronounced elevation of serum amyloid A (SAA) and developed increased plaque and necrotic core area already at 5 days, which reached significance at 15 days (p = 0.019; p = 0.004 for plaque and necrotic core, respectively). Macrophage and lymphocyte density significantly decreased in the surgery group compared to the control group at 15 days (p = 0.037; p = 0.024, respectively). The density of neutrophils and mast cells remained unchanged. CONCLUSIONS: Major orthopedic surgery in ApoE-/- mice triggers a systemic inflammatory response. Atherosclerotic plaque area is enlarged after surgery mainly due to an increase of the necrotic core. The role of intra-plaque inflammation in this response to surgical injury remains to be fully elucidated.

Prevention of age-induced N(ε)-(carboxymethyl)lysine accumulation in the microvasculature.

OBJECTIVE: N(ε)-(carboxymethyl)lysine (CML) is one of the major advanced glycation end products in both diabetics and nondiabetics. CML depositions in the microvasculature have recently been linked to the aetiology of acute myocardial infarction and cognitive impairment in Alzheimer's disease, possibly related to local enhancement of inflammation and oxidative processes. We hypothesized that CML deposition in the microvasculature of the heart and brain is age-induced and that it could be inhibited by a diet intervention with docosahexaenoic acid (DHA), an omega-3 fatty acid known for its anti-inflammatory and antioxidative actions. MATERIALS AND METHODS: ApoE(-/-) mice (n = 50) were fed a Western diet and were sacrificed after 40, 70 and 90 weeks. Part of these mice (n = 20) were fed a Western diet enriched with DHA from 40 weeks on. CML in cardiac and cerebral microvessels was quantified using immunohistochemistry. RESULTS: Cardiac microvascular depositions of CML significantly increased with an immunohistochemical score of 11·85 [5·92-14·60] at 40 weeks, to 33·17 [17·60-47·15] at 70 weeks (P = 0·005). At the same time points, cerebral microvascular CML increased from 6·45; [4·78-7·30] to 12·99; [9·85-20·122] (P = 0·003). DHA decreased CML in the intramyocardial vasculature at both 70 and 90 weeks, significant at 70 weeks [33·17; (17·60-47·15) vs. 14·73; (4·44-28·16) P = 0·037]. No such effects were found in the brain. CONCLUSIONS: Accumulation of N(ε)-(carboxymethyl)lysine in the cerebral and cardiac microvasculature is age-induced and is prevented by DHA in the intramyocardial vessels of ApoE(-/-) mice.