Beta-adrenergic blockers for perioperative cardiac risk reduction in people undergoing vascular surgery.

BACKGROUND: People undergoing major vascular surgery have an increased risk of postoperative cardiac complications. Beta-adrenergic blockers represent an important and established pharmacological intervention in the prevention of cardiac complications in people with coronary artery disease. It has been proposed that this class of drugs may reduce the risk of perioperative cardiac complications in people undergoing major non-cardiac vascular surgery. OBJECTIVES: To review the efficacy and safety of perioperative beta-adrenergic blockade in reducing cardiac or all-cause mortality, myocardial infarction, and other cardiovascular safety outcomes in people undergoing major non-cardiac vascular surgery. SEARCH METHODS: The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (January 2014) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2013, Issue 12). We searched trials databases and checked reference lists of relevant articles. SELECTION CRITERIA: We included prospective, randomised controlled trials of perioperative beta-adrenergic blockade of people over 18 years of age undergoing non-cardiac vascular surgery. DATA COLLECTION AND ANALYSIS: Two review authors independently performed study selection and data extraction. We resolved disagreements through discussion. We performed meta-analysis using a fixed-effect model with odds ratios (ORs) and 95% confidence intervals (CIs). MAIN RESULTS: We included two studies in this review, both of which were double-blind, randomised controlled trials comparing perioperative beta-adrenergic blockade (metoprolol) with placebo, on cardiovascular outcomes in people undergoing major non-cardiac vascular surgery. We included 599 participants receiving beta-adrenergic blockers (301 participants) or placebo (298 participants). The overall quality of studies was good. However, one study did not report random sequence generation or allocation concealment techniques, indicating possible selection bias, and the other study did not report outcome assessor blinding and was possibly underpowered. It should be noted that several of the outcomes were only reported in a single study and neither of the studies reported on vascular patency/graft occlusion, which reduces the quality of evidence to moderate. There was no evidence that perioperative beta-adrenergic blockade reduced all-cause mortality (OR 0.62, 95% CI 0.03 to 15.02), cardiovascular mortality (OR 0.34, 95% CI 0.01 to 8.32), non-fatal myocardial infarction (OR 0.83, 95% CI 0.46 to 1.49; P value = 0.53), arrhythmia (OR 0.70, 95% CI 0.26 to 1.88), heart failure (OR 1.71, 95% CI 0.40 to 7.23), stroke (OR 2.67, 95% CI 0.11 to 67.08), composite cardiovascular events (OR 0.87, 95% CI 0.55 to 1.39; P value = 0.57) or re-hospitalisation at 30 days (OR 0.86, 95% CI 0.48 to 1.52). However, there was strong evidence that beta-adrenergic blockers increased the odds of intra-operative bradycardia (OR 4.97, 95% CI 3.22 to 7.65; P value < 0.00001) and intra-operative hypotension (OR 1.84, 95% CI 1.31 to 2.59; P value = 0.0005). AUTHORS' CONCLUSIONS: This meta-analysis currently offers no clear evidence that perioperative beta-adrenergic blockade reduces postoperative cardiac morbidity and mortality in people undergoing major non-cardiac vascular surgery. There is evidence that intra-operative bradycardia and hypotension are more likely in people taking perioperative beta-adrenergic blockers, which should be weighed with any benefit.

Antiplatelet agents for preventing thrombosis after peripheral arterial bypass surgery.

BACKGROUND: Peripheral arterial disease (PAD) may cause occlusions (blockages) in the main arteries of lower limbs. One treatment option is bypass surgery using autologous (the patient's own tissue) vein graft or prosthetic (artificial) graft. A number of factors influence occlusion rates in these patients, including the material used. To prevent graft occlusion patients are usually treated with antiplatelet, antithrombotic drugs, or a combination of both. OBJECTIVES: To determine the effects of antiplatelet agents for the prevention of thrombosis in people with lower limb atherosclerosis who were undergoing femoropopliteal or femorodistal bypass grafting. Outcomes included the overall success of therapy (graft patency and limb salvage rates) and complications of treatment. SEARCH METHODS: For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched June 2014) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 5). We sought additional trials through screening the reference lists of relevant papers. SELECTION CRITERIA: Two review authors, RB and AL, independently reviewed studies found in the search and evaluated them based on the inclusion and exclusion criteria, resolving disagreements through discussion. DATA COLLECTION AND ANALYSIS: RB and AL independently extracted details of the selected studies for the update. We compared the treatment and control groups for important prognostic factors and differences described. If any data were unavailable, we sought further information from study authors. We synthesised data by comparing group results. We addressed unit of analysis issues by subgroup analysis. MAIN RESULTS: We include 16 studies with 5683 randomised participants. Nine different treatment groups were evaluated: aspirin (ASA) or aspirin and dipyridamole (ASA/DIP) versus placebo or nothing (six studies); ASA or ASA/DIP versus pentoxifylline (two studies); ASA/DIP versus indobufen (one study); ASA or ASA/DIP versus vitamin K antagonists (two studies); ASA/DIP versus low molecular weight heparin (one study); ticlopidine versus placebo (one study); ASA versus prostaglandin E1 (one study); ASA versus naftidrofuryl (one study); and clopidogrel and ASA versus ASA alone (one study). The treatment comparisons were evaluated separately, and, where possible, we performed subgroup analysis for venous grafts and prosthetic grafts and at different follow-up time points. The quality of evidence was low to moderate as many of the treatment comparisons had very few studies to contribute data, several of the included studies had unit of analysis issues, the treatment dosages varied between studies, and data for many outcomes important to this review were not given in any of the studies, or differed greatly between studies. Overall study quality was moderate, with the largest problem being that the majority of studies did not describe their methods of randomisation, allocation concealment or blinding of outcome assessors, leading to risk ratings of 'unclear'. The other main issue with study quality was studies not blinding participants or personnel.The treatment comparison with the most number of included studies, which allowed for robust conclusions, was that of aspirin (ASA) or ASA and dipyridamole (ASA/DIP) versus placebo or nothing, covered by six studies. For this treatment group, there was improved graft patency in the ASA or ASA/DIP treatment group, odds ratio (OR) 0.42 (95% confidence interval (CI) 0.22 to 0.83; P = 0.01; 952 participants). This effect was not seen for venous grafts alone at any of the time points, but was observed for all time points in prosthetic grafts, including the final time point of 12 months (OR 0.19, 95% CI 0.10 to 0.36; P < 0.00001; 222 participants). Only a single study evaluated secondary patency, for which there was no difference between treatment groups. For the comparison ASA or ASA/DIP versus placebo or nothing there was no difference for any of the side effects, including general, gastrointestinal, bleeding and wound/graft infection. Amputations, cardiovascular events and mortality were also similar between the treatment groups. The comparison of ASA or ASA/DIP versus vitamin K antagonists included two studies, one of which was very large, with over 2000 participants. There were no differences between treatment for primary graft patency at three, six, 12 or 24 months, and there was also no evidence of a difference for limb amputation, cardiovascular events or mortality. One large study (851 participants) evaluated clopidogrel and ASA versus ASA alone, and for all grafts there was no evidence of a difference of primary patency at 24 months. There was evidence of increased total bleeding in the clopidogrel and ASA group (OR 2.65, 95% CI 1.69 to 4.15) from an increase in mild (OR 2.34, 95% CI 1.37 to 4.00), and moderate bleeding (OR 4.13, 95% CI 1.37 to 12.45), but no difference in severe or fatal bleeding. There was no difference between the treatment groups for limb amputation or mortality. For the remaining treatment comparisons there is not currently enough evidence to draw any robust conclusions about the efficacy or safety of the treatment on graft patency after peripheral bypass. AUTHORS' CONCLUSIONS: Antiplatelet therapy with aspirin or with aspirin plus dipyridamole had a beneficial effect on primary patency of peripheral bypass grafts compared to placebo or no treatment. This effect was not evident when evaluating venous grafts alone, but antiplatelet therapy did have a beneficial effect on patency in those who had prosthetic grafts. There was no evidence of differences in side effects (including general, gastrointestinal, bleeding or infection), amputation, cardiovascular events or mortality between the treatment groups. However, the number of participants included in this analysis might be too small to detect a statistically significant effect for side effects, amputation, cardiovascular morbidity or mortality. We found no difference in primary graft patency when aspirin or aspirin with dipyridamole was compared to a vitamin K antagonist or when clopidogrel with aspirin was compared to aspirin alone. However, there was evidence of increase bleeding in the clopidogrel with aspirin group for the latter comparison. The remaining six treatment comparisons did not include enough data to draw any robust conclusions about their efficacy or safety at this time.

Cilostazol for intermittent claudication.

BACKGROUND: Peripheral arterial disease (PAD) affects between 4% and 12% of people aged 55 to 70 years, and 20% of people over 70 years. A common complaint is intermittent claudication, characterised by pain in the legs or buttocks that occurs with exercise and which subsides with rest. Compared with age-matched controls, people with intermittent claudication have a three- to six-fold increase in cardiovascular mortality. Symptoms of intermittent claudication, walking distance, and quality of life can be improved by risk factor modification, smoking cessation, and a structured exercise programme. Antiplatelet treatment is beneficial in patients with intermittent claudication for the reduction of vascular events but has not previously been shown to influence claudication distance. This is an update of a review first published in 2007. OBJECTIVES: To determine the effect of cilostazol (an antiplatelet treatment) on improving initial and absolute claudication distances, and in reducing mortality and vascular events in patients with stable intermittent claudication. SEARCH METHODS: For this update, the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched October 2013) and CENTRAL (2013, Issue 9). SELECTION CRITERIA: Double-blind, randomised controlled trials (RCTs) of cilostazol versus placebo, or versus other antiplatelet agents in patients with stable intermittent claudication. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials for selection and independently extracted data. Disagreements were resolved by discussion. We performed the meta-analysis as a fixed-effect model with weighted mean differences (WMDs) and 95% confidence intervals (CIs) for continuous data, and odds ratios (ORs) with 95% CIs for dichotomous data. MAIN RESULTS: We included fifteen double-blind, RCTs comparing cilostazol with placebo, or medications currently known to increase walking distance e.g. pentoxifylline. There were a total of 3718 randomised participants with treatment durations ranging from six to 26 weeks. All participants had intermittent claudication secondary to PAD. Comparisons included cilostazol twice daily, with dosages of 50 mg, 100 mg and 150 mg compared with placebo, and cilostazol 100 mg, twice daily, compared with pentoxifylline 400 mg, three times daily. The methodological quality of the trials was generally low, with the majority being at an unclear risk for selection bias, performance bias, detection bias and other bias. Attrition bias was generally low, but reporting bias was high or unclear in the majority of the studies. For eight studies data were compatible for comparison by meta-analysis, but data for seven studies were too heterogenous to be pooled. For the studies included in the meta-analysis, for initial claudication distance (ICD - the distance walked on a treadmill before the onset of calf pain) there was an improvement in the cilostazol group for the 100 mg and 50 mg twice daily, compared with placebo (WMD 31.41 metres, 95% CI 22.38 to 40.45 metres; P < 0.00001) and WMD 19.89 metres, 95% CI 9.44 to 30.34 metres; P = 0.0002), respectively. ICD was improved in the cilostazol group for the comparison of cilostazol 150 mg versus placebo and cilostazol 100 mg versus pentoxifylline, but only single studies were used for these analyses. Absolute claudication distance (ACD - the maximum distance walked on a treadmill) was significantly increased in participants taking cilostazol 100 mg and 50 mg twice daily, compared with placebo (WMD 43.12 metres, 95% CI 18.28 to 67.96 metres; P = 0.0007) and WMD 32.00 metres, 95% CI 14.17 to 49.83 metres; P = 0.0004), respectively. As with ICD, ACD was increased in participants taking cilostazol 150 mg versus placebo, but with only one study an association cannot be clearly determined. Two studies comparing cilostazol to pentoxifylline had opposing findings, resulting in an imprecise CI (WMD 13.42 metres (95% CI -43.51 to 70.35 metres; P = 0.64). Ankle brachial index (ABI) was lowered in the cilostazol 100 mg group compared with placebo (WMD 0.06, 95% CI 0.04 to 0.08; P < 0.00001). The single study evaluating ABI for the comparison of cilostazol versus pentoxifylline found no change in ABI.There was no association between treatment type and all-cause mortality for any of the treatment comparisons, but there were very few events, and therefore larger, adequately powered studies will be needed to assess if there is a relationship. Only one study evaluated individual cardiovascular events, and from this study there is no clear evidence of a difference between any of the treatment groups and risk of myocardial infarction or stroke. We evaluated adverse side effects, and in general cilostazol was associated with a higher odds of headache, diarrhoea, abnormal stool, dizziness and palpitations. We only reported quality of life measures descriptively as there was insufficient statistical detail within the studies to combine the results, although there was a possible indication in improvement of quality of life in the cilostazol treatment groups. AUTHORS' CONCLUSIONS: Cilostazol has been shown to be of benefit in improving walking distance in people with intermittent claudication secondary to PAD. Although there is an increase in adverse side effects, they are generally mild and treatable. There is currently insufficient data on whether taking cilostazol results in a reduction of all-cause mortality and cardiovascular events or an improvement in quality of life. Future research into the effect of cilostazol on intermittent claudication should carefully consider comparability, sample size and homogeneity when designing a study.

Association between severe hypoglycemia, adverse macrovascular events, and inflammation in the Edinburgh Type 2 Diabetes Study.

OBJECTIVE: To determine whether a history of severe hypoglycemia was associated with an increased risk of subsequent macrovascular events in people with type 2 diabetes and to explore possible mediation of this association by inflammation. RESEARCH DESIGN AND METHODS: A cohort of 1,066 adults aged 60-75 years with type 2 diabetes was evaluated prospectively. Baseline history of severe hypoglycemia and plasma levels of the inflammatory markers C-reactive protein, fibrinogen, interleukin-6, and tumor necrosis factor-α were recorded. Their association with incident macrovascular events after 4 years was explored. RESULTS: At baseline, 87 participants (8.2%) reported one or more episodes of severe hypoglycemia within the preceding year, and at follow-up 99 participants (9.3%) had suffered a new macrovascular event. Hypoglycemia was associated with increased odds of macrovascular events (odds ratio [OR] 2.11 [95% CI 1.06, 4.21], P = 0.035), including coronary heart events (OR 2.44 [95% CI 1.13, 5.26], P = 0.023), largely due to increased myocardial infarction (OR 4.02 [95% CI 1.54, 10.48], P = 0.004). Hypoglycemia was also associated with increased levels of inflammatory markers, including a general inflammation factor derived using principal-components analysis (P = 0.030, after adjustment for cardiometabolic risk factors). However, the significant association between hypoglycemia and macrovascular events persisted after adjustment for inflammatory markers. CONCLUSIONS: The odds of suffering a macrovascular event were higher in patients with type 2 diabetes who had a history of severe hypoglycemia. There was no evidence that a proinflammatory state had a major role in mediating this association.

Endovascular treatment for ruptured abdominal aortic aneurysm.

BACKGROUND: An abdominal aortic aneurysm (AAA) (pathological enlargement of the aorta) can develop in both men and women as they grow older. It is most commonly seen in men over the age of 65 years. Progressive aneurysm enlargement can lead to rupture and massive internal bleeding, a fatal event unless timely repair can be achieved. Despite improvements in perioperative care, mortality remains high (approximately 50%) after conventional open surgical repair. A newer minimally invasive technique, endovascular aneurysm repair (EVAR), has been shown to reduce early morbidity and mortality as compared to conventional open surgery for planned AAA repair. Emergency endovascular aneurysm repair (eEVAR) has been used successfully to treat ruptured abdominal aortic aneurysm (RAAA), proving that it is feasible in selected patients. However, it is not yet known if eEVAR will lead to significant improvements in outcomes for these patients or indeed if it can replace conventional open repair as the preferred treatment for this lethal condition. OBJECTIVES: To assess the advantages and disadvantages of emergency endovascular aneurysm repair (eEVAR) in comparison with conventional open surgical repair for the treatment of ruptured abdominal aortic aneurysm (RAAA). This will be determined by the effect on short-term mortality, major complication rates, aneurysm exclusion, and late complications when compared with the effects in patients who have had conventional open repair of RAAA. SEARCH METHODS: For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched February 2014) and CENTRAL (2014, Issue 2). Reference lists of relevant publications were also checked. SELECTION CRITERIA: Randomised controlled trials in which patients with a clinically or radiologically diagnosed RAAA were randomly allocated to eEVAR or conventional open surgical repair. DATA COLLECTION AND ANALYSIS: Studies identified for potential inclusion were independently assessed for eligibility by at least two review authors. Data extraction and quality assessment were also completed independently by two review authors. Disagreements were resolved through discussion. Meta-analysis was performed using fixed-effect models with odds ratios (ORs) and 95% confidence intervals (CIs) for dichotomous data and mean differences with 95% CIs for continuous data. MAIN RESULTS: Three randomised controlled trials were included in this review. A total of 761 patients with a clinical or radiological diagnosis of RAAA were randomised to receive either eEVAR or open surgical repair. Overall risk of bias was low but one study did not adequately report random sequence generation, putting it at risk of selection bias, two studies did not report on outcomes identified in their protocol, indicating reporting bias, and one study was underpowered. There was no clear evidence to support a difference between the two interventions on 30-day (or in-hospital) mortality, OR of 0.91 (95% CI 0.67 to 1.22; P = 0.52). The 30-day complications included myocardial infarction, stroke, composite cardiac complications, renal complications, severe bowel ischaemia, spinal cord ischaemia, re-operation, amputation, and respiratory failure. Individual complication outcomes were reported in only one or two studies and therefore no robust conclusion can currently be drawn. For complication outcomes that did include at least two studies in the meta-analysis there was no clear evidence to support a difference between eEVAR and open repair. Six-month outcomes were evaluated in only a single study, which included mortality and re-operation, with no clear evidence of a difference between the interventions and no overall association. Cost per patient was only evaluated in a single study and therefore no overall associations can currently be derived. AUTHORS' CONCLUSIONS: The conclusions of this review are currently limited by the paucity of data. From the data available there is no difference in the outcomes evaluated in this review between eEVAR and open repair, specifically 30-day mortality. Not enough information was provided for complications in order to make a well informed conclusion at this time. Long-term data are lacking for both survival and late complications. More high quality, randomised controlled trials comparing eEVAR and open repair for the treatment of RAAA are needed in order to better understand if one method is superior to the other, or if there is no difference between the methods on relevant outcomes.

Endovenous ablation (radiofrequency and laser) and foam sclerotherapy versus open surgery for great saphenous vein varices.

BACKGROUND: Minimally invasive techniques to treat great saphenous varicose veins include ultrasound-guided foam sclerotherapy (UGFS), radiofrequency ablation (RFA) and endovenous laser therapy (EVLT). Compared with flush saphenofemoral ligation with stripping, also referred to as open surgery or high ligation and stripping (HL/S), proposed benefits include fewer complications, quicker return to work, improved quality of life (QoL) scores, reduced need for general anaesthesia and equivalent recurrence rates. This is an update of a review first published in 2011. OBJECTIVES: To determine whether endovenous ablation (radiofrequency and laser) and foam sclerotherapy have any advantages or disadvantages in comparison with open surgical saphenofemoral ligation and stripping of great saphenous vein varices. SEARCH METHODS: For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched January 2014) and CENTRAL (2013, Issue 12). Clinical trials databases were also searched for details of ongoing or unpublished studies. SELECTION CRITERIA: All randomised controlled trials (RCTs) of UGFS, EVLT, RFA and HL/S were considered for inclusion. Primary outcomes were recurrent varicosities, recanalisation, neovascularisation, technical procedure failure, patient QoL scores and associated complications. DATA COLLECTION AND ANALYSIS: CN and RB independently reviewed, assessed and selected trials which met the inclusion criteria. CN and RB extracted data and used the Cochrane Collaboration's tool for assessing risk of bias. CN and RB contacted trial authors to clarify details as needed. MAIN RESULTS: For this update, eight additional studies were included making a total of 13 included studies with a combined total of 3081 randomised patients. Three studies compared UGFS with surgery, eight compared EVLT with surgery and five compared RFA with surgery (two studies had two or more comparisons with surgery). Study quality, evaluated through the six domains of risk of bias, was generally moderate for all included studies, however no study blinded participants, researchers and clinicians or outcome assessors. Also, nearly all included studies had other sources of bias. The overall quality of the evidence was moderate due to the variations in the reporting of results, which limited meaningful meta-analyses for the majority of proposed outcome measures. For the comparison UGFS versus surgery, the findings may have indicated no difference in the rate of recurrences in the surgical group when measured by clinicians, and no difference between the groups for symptomatic recurrence (odds ratio (OR) 1.74, 95% confidence interval (CI) 0.97 to 3.12; P = 0.06 and OR 1.28, 95% CI 0.66 to 2.49, respectively). Recanalisation and neovascularisation were only evaluated in a single study. Recanalisation at < 4 months had an OR of 0.66 (95% CI 0.20 to 2.12), recanalisation > 4 months an OR of 5.05 (95% CI 1.67 to 15.28) and for neovascularisation an OR of 0.05 (95% CI 0.00 to 0.94). There was no difference in the rate of technical failure between the two groups (OR 0.44, 95% CI 0.12 to 1.57). For EVLT versus surgery, there were no differences between the treatment groups for either clinician noted or symptomatic recurrence (OR 0.72, 95% CI 0.43 to 1.22; P = 0.22 and OR 0.87, 95% CI 0.47 to 1.62; P = 0.67, respectively). Both early and late recanalisation were no different between the two treatment groups (OR 1.05, 95% CI 0.09 to 12.77; P = 0.97 and OR 4.14, 95% CI 0.76 to 22.65; P = 0.10). Neovascularisation and technical failure were both statistically reduced in the laser treatment group (OR 0.05, 95% CI 0.01 to 0.22; P < 0.0001 and OR 0.29, 95% CI 0.14 to 0.60; P = 0.0009, respectively). Long-term (five-year) outcomes were evaluated in one study so no association could be derived,but it appeared that EVLT and surgery maintained similar findings. Comparing RFA versus surgery, there were no differences in clinician noted recurrence (OR 0.82, 95% CI 0.49 to 1.39; P = 0.47); symptomatic noted recurrence was only evaluated in a single study. There were also no differences between the treatment groups for recanalisation (early or late) (OR 0.68, 95% CI 0.01 to 81.18; P = 0.87 and OR 1.09, 95% CI 0.39 to 3.04; P = 0.87, respectively), neovascularisation (OR 0.31, 95% CI 0.06 to 1.65; P = 0.17) or technical failure (OR 0.82, 95% CI 0.07 to 10.10; P = 0.88).QoL scores, operative complications and pain were not amenable to meta-analysis, however quality of life generally increased similarly in all treatment groups and complications were generally low, especially major complications. Pain reporting varied greatly between the studies but in general pain was similar between the treatment groups. AUTHORS' CONCLUSIONS: Currently available clinical trial evidence suggests that UGFS, EVLT and RFA are at least as effective as surgery in the treatment of great saphenous varicose veins. Due to large incompatibilities between trials and different time point measurements for outcomes, the evidence is lacking in robustness. Further randomised trials are needed, which should aim to report and analyse results in a congruent manner to facilitate future meta-analysis.

Heparin for the prevention of venous thromboembolism in acutely ill medical patients (excluding stroke and myocardial infarction).

BACKGROUND: Venous thromboembolic disease has been extensively studied in surgical patients. The benefit of thromboprophylaxis is now generally accepted, but it is medical patients who make up the greater proportion of the hospital population. Medical patients differ from surgical patients with regard to their health and the pathogenesis of thromboembolism and the impact that preventative measures can have. The extensive experience from thromboprophylaxis studies in surgical patients is therefore not necessarily applicable to non-surgical patients. This is an update of a review first published in 2009. OBJECTIVES: To determine the effectiveness and safety of heparin (unfractionated heparin or low molecular weight heparin) thromboprophylaxis in acutely ill medical patients admitted to hospital, excluding those admitted to hospital with an acute myocardial infarction or stroke (ischaemic or haemorrhagic) or those requiring admission to an intensive care unit. SEARCH METHODS: For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched November 2013) and CENTRAL (2013, Issue 10). SELECTION CRITERIA: Randomised controlled trials comparing unfractionated heparin (UFH) or low molecular weight heparin (LMWH) with placebo or no treatment, or comparing UFH with LMWH. DATA COLLECTION AND ANALYSIS: One review author identified possible trials and a second review author confirmed their eligibility for inclusion in the review. Two review authors extracted the data. Disagreements were resolved by discussion. We performed the meta-analysis using a fixed-effect model with the results expressed as odds ratios (ORs) with 95% confidence intervals (CIs). MAIN RESULTS: Sixteen studies with a combined total of 34,369 participants with an acute medical illness were included in this review. We identified 10 studies comparing heparin with placebo or no treatment and six studies comparing LMWH to UFH. Just under half of the studies had an open-label design, putting them at a risk of performance bias. Descriptions of random sequence generation and allocation concealment were missing in most of the studies. Heparin reduced the odds of deep vein thrombosis (DVT) (OR 0.38; 95% CI 0.29 to 0.51; P < 0.00001). The estimated reductions in symptomatic non-fatal pulmonary embolism (PE) (OR 0.46; 95% CI 0.19 to 1.10; P = 0.08), fatal PE (OR 0.71; 95% CI 0.43 to 1.15; P = 0.16) and in combined non-fatal PE and fatal PE (OR 0.65; 95% CI 0.42 to 1.00; P = 0.05) associated with heparin were imprecise. Heparin resulted in an increase in major haemorrhage (OR 1.81; 95% CI 1.10 to 2.98; P = 0.02). There was no clear evidence that heparin had an effect on all-cause mortality and thrombocytopaenia. Compared with UFH, LMWH reduced the risk of DVT (OR 0.77; 95% CI 0.62 to 0.96; P = 0.02) and major bleeding (OR 0.43; 95% CI 0.22 to 0.83; P = 0.01). There was no clear evidence that the effects of LMWH and UFH differed for the PE outcomes, all-cause mortality and thrombocytopaenia. AUTHORS' CONCLUSIONS: The data from this review describe a reduction in the risk of DVT in patients presenting with an acute medical illness who receive heparin thromboprophylaxis. This needs to be balanced against an increase in the risk of bleeding associated with thromboprophylaxis. The analysis favoured LMWH compared with UFH, with a reduced risk of both DVT and bleeding.

The long noncoding RNA SChLAP1 promotes aggressive prostate cancer and antagonizes the SWI/SNF complex.

Prostate cancers remain indolent in the majority of individuals but behave aggressively in a minority. The molecular basis for this clinical heterogeneity remains incompletely understood. Here we characterize a long noncoding RNA termed SChLAP1 (second chromosome locus associated with prostate-1; also called LINC00913) that is overexpressed in a subset of prostate cancers. SChLAP1 levels independently predict poor outcomes, including metastasis and prostate cancer-specific mortality. In vitro and in vivo gain-of-function and loss-of-function experiments indicate that SChLAP1 is critical for cancer cell invasiveness and metastasis. Mechanistically, SChLAP1 antagonizes the genome-wide localization and regulatory functions of the SWI/SNF chromatin-modifying complex. These results suggest that SChLAP1 contributes to the development of lethal cancer at least in part by antagonizing the tumor-suppressive functions of the SWI/SNF complex.

GAS6 receptor status is associated with dormancy and bone metastatic tumor formation.

Disseminated tumor cells (DTCs) are believed to lie dormant in the marrow before they can be activated to form metastases. How DTCs become dormant in the marrow and how dormant DTCs escape dormancy remains unclear. Recent work has shown that prostate cancer (PCa) cell lines express the growth-arrest specific 6 (GAS6) receptors Axl, Tyro3, and Mer, and become growth arrested in response to GAS6. We therefore hypothesized that GAS6 signaling regulates the proliferative activity of DTCs in the marrow. To explore this possibility, in vivo studies were performed where it was observed that when Tyro3 expression levels exceed Axl expression, the PCa cells exhibit rapid growth. When when Axl levels predominate, PCa cells remain largely quiescent. These findings suggest that a balance between the expression of Axl and Tyro3 is associated with a molecular switch between a dormant and a proliferative phenotype in PCa metastases.

Micro-ring structures stabilize microdroplets to enable long term spheroid culture in 384 hanging drop array plates.

Using stereolithography, 20 different structural variations comprised of millimeter diameter holes surrounded by trenches, plateaus, or micro-ring structures were prepared and tested for their ability to stably hold arrays of microliter sized droplets within the structures over an extended period of time. The micro-ring structures were the most effective in stabilizing droplets against mechanical and chemical perturbations. After confirming the importance of micro-ring structures using rapid prototyping, we developed an injection molding tool for mass production of polystyrene 3D cell culture plates with an array of 384 such micro-ring surrounded through-hole structures. These newly designed and injection molded polystyrene 384 hanging drop array plates with micro-rings were stable and robust against mechanical perturbations as well as surface fouling-facilitated droplet spreading making them capable of long term cell spheroid culture of up to 22 days within the droplet array. This is a significant improvement over previously reported 384 hanging drop array plates which are susceptible to small mechanical shocks and could not reliably maintain hanging drops for longer than a few days. With enhanced droplet stability, the hanging drop array plates with micro-ring structures provide better platforms and open up new opportunities for high-throughput preparation of microscale 3D cell constructs for drug screening and cell analysis.