Little Impact of Antiplatelet Agents on Venous Thromboembolism after Hip Fracture Surgery

Since the late 1980s, low dose aspirin has been used to prevent stroke and ischemic heart disease. However, prophylactic effect of antiplatelets against venous thromboembolism (VTE), in patients who undergo hip fracture surgery (HFS) is controversial. Our purpose was to determine the incidence of symptomatic VTE after HFS and to evaluate whether antiplatelets reduce the development of symptomatic VTE following HFS. We retrospectively reviewed 858 HFS in 824 consecutive patients which were performed from May 2003 to April 2010 at an East Asian institute. We compared the incidence of symptomatic VTE in antiplatelet users and non-users using multivariate logistic regression analyses. Overall incidences of symptomatic pulmonary embolism including fatal pulmonary embolism, and symptomatic deep vein thrombosis in this study were 2.4% (21/858), and 3.5% (30/858), respectively. The incidence of symptomatic VTE was 4.8% (12/250) in antiplatelet users and 4.3% (26/608) in non-users (P = 0.718). It is suggested that antiplatelet agents are not effective in prevention of symptomatic VTE after HFS

Renal artery stenosis-when to screen, what to stent?

Renal artery stensosis (RAS) continues to be a problem for clinicians, with no clear consensus on how to investigate and assess the clinical significance of stenotic lesions and manage the findings. RAS caused by fibromuscular dysplasia is probably commoner than previously appreciated, should be actively looked for in younger hypertensive patients and can be managed successfully with angioplasty. Atheromatous RAS is associated with increased incidence of cardiovascular events and increased cardiovascular mortality, and is likely to be seen with increasing frequency. Evidence from large clinical trials has led clinicians away from recommending interventional revascularisation towards aggressive medical management. There is now interest in looking more closely at patient selection for intervention, with focus on intervening only in patients with the highest-risk presentations such as flash pulmonary oedema, rapidly declining renal function and severe resistant hypertension. The potential benefits in terms of improving hard cardiovascular outcomes may outweigh the risks of intervention in this group, and further research is needed

Clopidogrel-induced Spontaneous Spinal Epidural Hematoma

The hemorrhagic side effects associated with the use of clopidogrel are within the acceptable range and occur mainly at skin or gastrointestinal sites. We report a case of spontaneous spinal epidural hematoma (SSEH) in a 60-yr-old woman who was treated with clopidogrel for frequent transient ischemic attacks. To our knowledge, this is the second reported case of clopidogrel-induced SSEH. The patient's symptoms and past history of clopidogrel use suggested the diagnosis and made the procedure proceed quickly to operate SSEH 9 hr after the onset of paraplegia. The outcome was excellent. Therefore, with the popularity of antiplatelet prescription, physicians should keep in mind and urgently treat this unusual but critical side effect

Peripheral arterial disease: A high risk – but neglected – disease population

Peripheral arterial disease (PAD) is a common, progressive manifestation of atherothrombotic vascular disease, which should be managed no different to cardiac disease. Indeed, there is growing evidence that PAD patients are a high risk group, although still relatively under-detected and under treated. This is despite the fact that PAD patients are an increased mortality rate comparable to those with pre-existing or established cardiovascular disease [myocardial infarction, stroke]. With a holistic approach to atherothrombotic vascular disease, our management of PAD can only get better

Adapting a Markov Monte Carlo simulation model for forecasting the number of Coronary Artery Revascularisation Procedures in an era of rapidly changing technology and policy

<p>Abstract</p> <p>Background</p> <p>Treatments for coronary heart disease (CHD) have evolved rapidly over the last 15 years with considerable change in the number and effectiveness of both medical and surgical treatments. This period has seen the rapid development and uptake of statin drugs and coronary artery revascularization procedures (CARPs) that include Coronary Artery Bypass Graft procedures (CABGs) and Percutaneous Coronary Interventions (PCIs). It is difficult in an era of such rapid change to accurately forecast requirements for treatment services such as CARPs. In a previous paper we have described and outlined the use of a Markov Monte Carlo simulation model for analyzing and predicting the requirements for CARPs for the population of Western Australia (Mannan et al, 2007). In this paper, we expand on the use of this model for forecasting CARPs in Western Australia with a focus on the lack of adequate performance of the (standard) model for forecasting CARPs in a period during the mid 1990s when there were considerable changes to CARP technology and implementation policy and an exploration and demonstration of how the standard model may be adapted to achieve better performance.</p> <p>Methods</p> <p>Selected key CARP event model probabilities are modified based on information relating to changes in the effectiveness of CARPs from clinical trial evidence and an awareness of trends in policy and practice of CARPs. These modified model probabilities and the ones obtained by standard methods are used as inputs in our Markov simulation model.</p> <p>Results</p> <p>The projected numbers of CARPs in the population of Western Australia over 1995–99 only improve marginally when modifications to model probabilities are made to incorporate an increase in effectiveness of PCI procedures. However, the projected numbers improve substantially when, in addition, further modifications are incorporated that relate to the increased probability of a PCI procedure and the reduced probability of a CABG procedure stemming from changed CARP preference following the introduction of PCI operations involving stents.</p> <p>Conclusion</p> <p>There is often knowledge and sometimes quantitative evidence of the expected impacts of changes in surgical practice and procedure effectiveness and these may be used to improve forecasts of future requirements for CARPs in a population.</p

Why are eligible patients not prescribed aspirin in primary care? A qualitative study indicating measures for improvement

BACKGROUND: Despite evidence-based guidelines, aspirin prescribing for the secondary prevention of stroke is sub-optimal. Little is known about why general practitioners do not prescribe aspirin to indicated patients. We sought to identify and describe factors that lead general practitioners (GPs) not to prescribe aspirin to eligible stroke patients. This was the first stage of a study exploring the need for and means of improving levels of appropriate aspirin prescribing. METHOD: Qualitative interviews with 15 GPs in the West Midlands. RESULTS: Initially, many GPs did not regard their prescribing as difficult or sub-optimal. However on reflection, they gave several reasons that lead to them not prescribing aspirin for eligible patients or being uncertain. These include: difficulties in applying generic guidelines to individuals presenting in consultations, patient resistance to taking aspirin, the prioritisation of other issues in a time constrained consultation and problems in reviewing the medication of existing stroke patients. CONCLUSION: In order to improve levels of appropriate aspirin prescribing, the nature and presentation risk information available to GPs and patients must be improved. GPs need support in assessing the risks and benefits of prescribing for patients with combinations of complicating risk factors, while means of facilitating improved GP-patient dialogue are required to help address patient uncertainty. A decision analysis based support system is one option. Decision analysis could synthesise current evidence and identify risk data for a range of patient profiles commonly presenting in primary care. These data could then be incorporated into a user-friendly computerised decision support system to help facilitate improved GP-patient communication. Measures of optimum prescribing based upon aggregated prescribing data must be interpreted with caution. It is not possible to assess whether low levels of prescribing reflect appropriate or inappropriate use of aspirin in specific patients where concordance between the GP and the patient is practised

An outreach intervention to implement evidence based practice in residential care: a randomized controlled trial [ISRCTN67855475]

BACKGROUND: The aim of this project was to assess whether outreach visits would improve the implementation of evidence based clinical practice in the area of falls reduction and stroke prevention in a residential care setting. METHODS: Twenty facilities took part in a randomized controlled trial with a seven month follow-up period. Two outreach visits were delivered by a pharmacist. At the first a summary of the relevant evidence was provided and at the second detailed audit information was provided about fall rates, psychotropic drug prescribing and stroke risk reduction practices (BP monitoring, aspirin and warfarin use) for the facility relevant to the physician. The effect of the interventions was determined via pre- and post-intervention case note audit. Outcomes included change in percentage patients at risk of falling who fell in a three month period prior to follow-up and changes in use of psychotropic medications. Chi-square tests, independent samples t-test, and logistic regression were used in the analysis. RESULTS: Data were available from case notes at baseline (n = 897) and seven months follow-up (n = 902), 452 residential care staff were surveyed and 121 physicians were involved with 61 receiving outreach visits. Pre-and post-intervention data were available for 715 participants. There were no differences between the intervention and control groups for the three month fall rate. We were unable to detect statistically significant differences between groups for the psychotropic drug use of the patients before or after the intervention. The exception was significantly greater use of "as required" antipsychotics in the intervention group compared with the control group after the pharmacy intervention (RR = 4.95; 95%CI 1.69–14.50). There was no statistically significant difference between groups for the numbers of patients "at risk of stroke" on aspirin at follow-up. CONCLUSIONS: While the strategy was well received by the physicians involved, there was no change in prescribing patterns. Patient care in residential settings is complex and involves contributions from the patient's physician, family and residential care staff. The project highlights challenges of delivering evidence based care in a setting in which there is a paucity of well controlled trial evidence but where significant health outcomes can be attained

Increased blood product use among coronary artery bypass patients prescribed preoperative aspirin and clopidogrel

BACKGROUND: The administration of antiplatelet drugs before coronary artery bypass graft surgery (CABG) is associated with an increased risk of major hemorrhage and related surgical reexploration. Little is known about the relative effect of combined clopidogrel and aspirin on blood product use around the time of CABG. We evaluated the associated risk between the combined use of aspirin and clopidogrel and the transfusion of blood products perioperatively. METHODS: We retrospectively studied a cohort of 659 individuals who underwent a first CABG, without concomitant valvular or aortic surgery, at a single large Canadian cardiac surgical centre between January 2000 and April 2002. The four study exposure groups were those prescribed aspirin (n = 105), clopidogrel (n = 11), the combination of both (n = 46), or neither drug (n = 497), within 7 days prior to CABG. The primary study outcome was the excessive transfusion of blood products during CABG and up to the second post-operative day, defined as ≥ 2 units of packed red blood cells (PRBC), ≥ 2 units of fresh frozen plasma, ≥ 5 units of cryoprecipitate or ≥ 5 units of platelets. Secondary outcomes included the mean number of transfused units of each type of blood product. RESULTS: A greater mean number of units of PRBC were transfused among those who received clopidogrel alone (2.9) or in combination with aspirin (2.4), compared to those on aspirin alone (1.9) or neither antiplatelet drug (1.4) (P = 0.001). A similar trend was seen for the respective mean number of transfused units of platelets (3.6, 3.7, 1.3 and 1.0; P < 0.001) and fresh frozen plasma (2.5, 3.1, 2.3, 1.6; P = 0.01). Compared to non-users, the associated risk of excessive blood product transfusion was highest among recipients of aspirin and clopidogrel together (adjusted OR 2.2, 95% CI 1.1–4.3). No significant association was seen among lone users of aspirin (adjusted OR 1.0, 95% CI 0.6–1.6) or clopidogrel (adjusted OR 0.7, 95% CI 0.2–2.5), compared to non-users. CONCLUSIONS: While combined use of aspirin and clopidogrel shortly before CABG surgery may increase the associated risk of excess transfusion of blood products perioperatively, several study limitations prevent any confident conclusions from being drawn. Beyond challenging these findings, future research might focus on the value of both intraoperative monitoring of platelet function, and the effectiveness of antifibrinolytic agents, at reducing the risk of postoperative bleeding