Apelin improves cardiac function mainly through peripheral vasodilation in a mouse model of dilated cardiomyopathy

There is growing evidence that apelin plays a role in the regulation of the cardiovascular system by increasing myocardial contractility and acting as a vasodilator. However, it remains unclear whether apelin improves cardiac contractility in a load-dependent or independent manner in pathological conditions. For this purpose we investigated the cardiovascular effects of apelin in α-actin transgenic mice (mActin-Tg mice), a model of cardiomyopathy. [Pyr¹]apelin-13 was administered by continuous infusion at 2 mg/kg/d for 3 weeks. Effects on cardiac function were determined by echocardiography and a Pressure-Volume (PV) analysis. mActin-Tg mice showed a dilated cardiomyopathy (DCM) phenotype similar to that encountered in patients expressing the same mutation. Compared to WT animals, mActin-Tg mice displayed cardiac systolic impairment [significant decrease in ejection fraction (EF), cardiac output (CO), and stroke volume (SV)] associated with cardiac ventricular dilation and diastolic dysfunction, characterized by an impairment in mitral flow velocity (E/A) and in deceleration time (DT). Load-independent myocardial contractility was strongly decreased in mActin-Tg mice while total peripheral vascular resistance (TPR) was significantly increased. As compared to vehicle-treated animals, a 3-week treatment with [Pyr¹]apelin-13 significantly improved EF%, SV, E/A, DT and corrected TPR, with no significant effect on load-independent indices of myocardial contractility, blood pressure and heart rate. In conclusion [Pyr¹]apelin-13 displayed no intrinsic contractile effect but improved cardiac function in dilated cardiomyopathy mainly by reducing peripheral vascular resistance, with no change in blood pressure.

Ablation of lysozyme M-positive cells prevents aircraft noise-induced vascular damage without improving cerebral side effects

Aircraft noise induces vascular and cerebral inflammation and oxidative stress causing hypertension and cardiovascular/cerebral dysfunction. With the present studies, we sought to determine the role of myeloid cells in the vascular vs. cerebral consequences of exposure to aircraft noise. Toxin-mediated ablation of lysozyme M+ (LysM+) myeloid cells was performed in LysMCreiDTR mice carrying a cre-inducible diphtheria toxin receptor. In the last 4d of toxin treatment, the animals were exposed to noise at maximum and mean sound pressure levels of 85 and 72 dB(A), respectively. Flow cytometry analysis revealed accumulation of CD45+, CD11b+, F4/80+, and Ly6G-Ly6C+ cells in the aortas of noise-exposed mice, which was prevented by LysM+ cell ablation in the periphery, whereas brain infiltrates were even exacerbated upon ablation. Aircraft noise-induced increases in blood pressure and endothelial dysfunction of the aorta and retinal/mesenteric arterioles were almost completely normalized by ablation. Correspondingly, reactive oxygen species in the aorta, heart, and retinal/mesenteric vessels were attenuated in ablated noise-exposed mice, while microglial activation and abundance in the brain was greatly increased. Expression of phagocytic NADPH oxidase (NOX-2) and vascular cell adhesion molecule-1 (VCAM-1) mRNA in the aorta was reduced, while NFκB signaling appeared to be activated in the brain upon ablation. In sum, we show dissociation of cerebral and peripheral inflammatory reactions in response to aircraft noise after LysM+ cell ablation, wherein peripheral myeloid inflammatory cells represent a dominant part of the pathomechanism for noise stress-induced cardiovascular effects and their central nervous counterparts, microglia, as key mediators in stress responses.

Rationale and design of ApoA-I Event Reducing in Ischemic Syndromes II (AEGIS-II): A phase 3, multicenter, double-blind, randomized, placebo-controlled, parallel-group study to investigate the efficacy and safety of CSL112 in subjects after acute myocardial infarction

Acute myocardial infarction (MI) patients remain at high risk for recurrent events. Cholesterol efflux, mediated by apolipoprotein A-I, removes excess cholesterol from atherosclerotic plaque and transports it to the liver for excretion. Impaired cholesterol efflux is associated with higher cardiovascular (CV) event rates among both patients with stable coronary artery disease and recent MI. CSL112, a novel intravenous formulation of apolipoprotein A-I (human) derived from human plasma, increases cholesterol efflux capacity. AEGIS-II is a phase 3, multicenter, double-blind, randomized, placebo-controlled, parallel-group trial investigating the efficacy and safety of CSL112 compared to placebo among high-risk acute MI participants. Eligibility criteria include age ≥ 18 years with type 1 (spontaneous) MI, evidence of multivessel stable coronary artery disease, and presence of diabetes requiring pharmacotherapy, or ≥2 of the following: age ≥ 65 years, prior MI, or peripheral artery disease. A target sample of 17,400 participants will be randomized 1:1 to receive 4 weekly infusions of CSL112 6 g or placebo, initiated prior to or on the day of discharge and within 5 days of first medical contact. The primary outcome is the time to first occurrence of the composite of CV death, MI, or stroke through 90 days. Key secondary outcomes include the total number of hospitalizations for coronary, cerebral, or peripheral ischemia through 90 days and time to first occurrence of the composite primary outcome through 180 and 365 days. AEGIS-II will be the first trial to formally test whether enhancing cholesterol efflux can reduce the rate of recurrent major adverse CV events.

Hydroxyurea Dose Escalation for Sickle Cell Anemia in Sub-Saharan Africa

BACKGROUND

Hydroxyurea has proven safety, feasibility, and efficacy in children with sickle cell anemia in sub-Saharan Africa, with studies showing a reduced incidence of vaso-occlusive events and reduced mortality. Dosing standards remain undetermined, however, and whether escalation to the maximum tolerated dose confers clinical benefits that outweigh treatment-related toxic effects is unknown.

METHODS

In a randomized, double-blind trial, we compared hydroxyurea at a fixed dose (approximately 20 mg per kilogram of body weight per day) with dose escalation (approximately 30 mg per kilogram per day). The primary outcome was a hemoglobin level of 9.0 g or more per deciliter or a fetal hemoglobin level of 20% or more after 24 months. Secondary outcomes included the incidences of malaria, vaso-occlusive crises, and serious adverse events.

RESULTS

Children received hydroxyurea at a fixed dose (94 children; mean [±SD] age, 4.6±1.0 years) or with dose escalation (93 children; mean age, 4.8±0.9 years); the mean doses were 19.2±1.8 mg per kilogram per day and 29.5±3.6 mg per kilogram per day, respectively. The data and safety monitoring board halted the trial when the numbers of clinical events were significantly lower among children receiving escalated dosing than among those receiving a fixed dose. At trial closure, 86% of the children in the dose-escalation group had reached the primary-outcome thresholds, as compared with 37% of the children in the fixed-dose group (P<0.001). Children in the dose-escalation group had fewer sickle cell-related adverse events (incidence rate ratio, 0.43; 95% confidence interval [CI], 0.34 to 0.54), vaso-occlusive pain crises (incidence rate ratio, 0.43; 95% CI, 0.34 to 0.56), cases of acute chest syndrome or pneumonia (incidence rate ratio, 0.27; 95% CI, 0.11 to 0.56), transfusions (incidence rate ratio, 0.30; 95% CI, 0.20 to 0.43), and hospitalizations (incidence rate ratio, 0.21; 95% CI, 0.13 to 0.34). Laboratory-confirmed dose-limiting toxic effects were similar in the two groups, and there were no cases of severe neutropenia or thrombocytopenia.

CONCLUSIONS

Among children with sickle cell anemia in sub-Saharan Africa, hydroxyurea with dose escalation had superior clinical efficacy to that of fixed-dose hydroxyurea, with equivalent safety. (Funded by the Doris Duke Charitable Foundation and the Cincinnati Children's Research Foundation; NOHARM MTD ClinicalTrials.gov number, NCT03128515.).

Novel treatment of severe radial artery spasm using "homemade sheathless technique": A case report

RATIONALE

Transradial access (TRA) is common for cardiac catheterization, but radial artery spasm (RAS) is suggested to be highlighted. Severe radical artery spasm could be solved by a relative novel approach called "sheathless technique," using a Tiger diagnostic catheter.

PATIENT CONCERNS

A 73-year-old woman presented to our institution with a recurrent feeling of discomfort in her chest. Her electrocardiogram showed ST segment depression. Her medical history indicated arterial hypertension, diabetes, and chronic renal failure. She was on hemodialysis for 5 years for the management of renal problems. Five stents were implanted from femoral access in another hospital via 2 percutaneous coronary interventions. The patient agreed to angiography this time and wanted a more comfortable solution.

DIAGNOSIS

Recurrent exertional angina was confirmed based on the chief complaint, electrocardiogram, and history.

INTERVENTIONS

After a successful radial artery puncture, a 6F arterial sheath pipe and a 5F Tiger diagnostic ductus could only advance slightly because of the RAS. Glonoin and verapamil functioned with the help of the radial sheath, and systemic nitroglycerin was applied later but had a negative outcome. Warm covers were positioned on the antebrachium, but no relief was reported.The "homemade sheathless technique" was applied. The 5F tube was held, and the 6F sheath was withdrawn. A blade was used to damage the sheath in reverse, and the excess sheath tube was removed.

OUTCOMES

The diagnostic catheter was successfully advanced to the ascending aorta, enabling left main and right coronary engagement and angiography. No significant coronary lesion was observed. The patient was discharged 3 days after angiography. Moreover, no complications were observed. A follow-up for 1 month after discharge also showed no complications.

LESSONS

Severe RAS causing failure of TRA is frequent in the transradial catheterization procedure. The sheathless technique may be useful in relieving spasm when other measures fail.

Anti-oxidative treatment with vitamin E improves peripheral vascular function in patients with diabetes mellitus and Haptoglobin 2-2 genotype: A double-blinded cross-over study

Vascular dysfunction in both conduit arteries and small vessels is a major contributor to the development of cardiovascular disease (CVD) in diabetes mellitus (DM). In diabetes there is a process of systemic chronic inflammation accompanied by high oxidative stress causing a subsequent decrease in vascular reactivity and negatively affect the metabolic processes responsible for functioning of the microvasculature. Vitamin E is classified as an antioxidant due to its ability to scavenge lipid radicals and terminate oxidative chain reactions. We conducted a double-blinded cross-over study with vitamin E versus placebo in individuals with type 2DM and the Hp2-2 genotype and assessed different aspects of peripheral vascular function in these patients. Twenty patients completed the study with 10 individuals in each study cohort. We were able to show significant improvement of indirect indices of vascular function following 8weeks of treatment with vitamin E. This improvement was consistent for weeks even after stopping the vitamin E treatment. We concluded that a pharmacogenomic rationale utilizing the Hp genotype might potentially provide cardiovascular benefit with vitamin E.

Predictors of Failure of Endovascular Therapy for Peripheral Arterial Disease

The objective of this study was to assess the usefulness of a comparison of clinical failure and restenosis rates of endovascular procedures at 1 year in patients with peripheral arterial disease. The resulting comparison is presented as “clinical failure/restenosis coordinate.” The authors screened 171 papers describing the outcome of lower extremity angioplasty or stent placement. In 20 of them, authors reported detailed outcomes of interest, including baseline demographic measurements, location of arterial occlusive lesions, a measure of restenosis (measured by ankle-brachial indices, ultrasonography, or angiography), and clinical outcomes (mortality, repeat percutaneous transluminal angioplasty, or amputation). An overview of these 20 angioplasty papers was performed. Besides the usual meta-analyses of each end point separately, data were also plotted as coordinates of clinical failure versus restenosis. The clinical failure-to-restenosis coordinate was calculated and reported for percutaneous transluminal angioplasty of the aortoiliac and femoropopliteal distributions. Clinically reported outcomes in the literature were used to calculate the clinical failure/restenosis coordinate. This value was significantly different for various locations of the angioplasty and various baseline angiographic characteristics. A numeric coordinate pair of clinical failure and restenosis is identifiable in patients undergoing endovascular treatment of peripheral arterial disease. The varying coordinates may be important in elucidating the incidence and mechanisms of clinical failure after endovascular treatment. The coordinate reported in this article is hypothesis-generating about mechanisms of endovascular treatment failure. This coordinate is important in determining the role of restenosis in the clinical failure of endovascular therapy of peripheral arterial disease.

Dyslipoproteinemia and Peripheral Arterial Occlusive Disease

Peripheral arterial occlusive disease (PAOD) is common in older age. PAOD is associated with an increased risk of vascular events (eg, myocardial infarction or stroke). Therefore, the prevention and treatment of PAOD is important, especially at a time when the elderly population is increasing. There is an association between lipid abnormalities and the risk of developing PAOD. However, it is not yet definitively established that early intervention with lipid-lowering drugs prevents the development of PAOD. There is evidence that vascular events in patients with PAOD can be significantly reduced by statins and that the symptoms associated with PAOD are improved by this treatment. There is an urgent need for appropriately designed lipid-lowering trials in patients with PAOD.

Hormone Replacement Therapy and Peripheral Vascular Disease in Women

Women have been shown to have a lower incidence of vascular disease when compared to men. However, the incidence of vascular disease increases as women progress through menopause and reaches an incidence similar to that of men later in life. Women with peripheral vascular disease often have a delay in diagnosis, a higher incidence of asymptomatic disease, and poorer outcome after interventions. The differences in outcome have been attributed to a number of factors such as anatomic and hormonal differences. It is thought that estrogen deficiency is at least partially responsible for the increased risk of developing vascular disease after menopause, and thus hormone replacement therapy has been considered as a method to prevent progression of vascular disease. Conclusions drawn from a number of recent studies have resulted in a divergent view of hormone replacement therapy (HRT). This article explores the risk of peripheral vascular disease in women and the current state of research on hormone replacement therapy. The aims of this review are to present current perspectives on gender differences in the pathogenesis and outcomes of peripheral arterial disease (PAD). The effect of estrogen on atherogenesis, the role it plays in modulating the vascular endothelium, and the current evidence of the effects of HRT on vascular pathology is discussed. The most recent HRT clinical trials and present evidence for the benefits and risks of postmenopausal hormone replacement therapy are summarized. The effect of these issues on treatment practices is explained and suggestions are made for future directions of HRT and PAD research.

A Multinational Trial of Prasugrel for Sickle Cell Vaso-Occlusive Events

BACKGROUND

Sickle cell anemia is an inherited blood disorder that is characterized by painful vaso-occlusive crises, for which there are few treatment options. Platelets mediate intercellular adhesion and thrombosis during vaso-occlusion in sickle cell anemia, which suggests a role for antiplatelet agents in modifying disease events.

METHODS

Children and adolescents 2 through 17 years of age with sickle cell anemia were randomly assigned to receive oral prasugrel or placebo for 9 to 24 months. The primary end point was the rate of vaso-occlusive crisis, a composite of painful crisis or acute chest syndrome. The secondary end points were the rate of sickle cell-related pain and the intensity of pain, which were assessed daily with the use of pain diaries.

RESULTS

A total of 341 patients underwent randomization at 51 sites in 13 countries across the Americas, Europe, Asia, and Africa. The rate of vaso-occlusive crisis events per person-year was 2.30 in the prasugrel group and 2.77 in the placebo group (rate ratio, 0.83; 95% confidence interval, 0.66 to 1.05; P=0.12). There were no significant differences between the groups in the secondary end points of diary-reported events. The safety end points, including the frequency of bleeding events requiring medical intervention, of hemorrhagic and nonhemorrhagic adverse events that occurred while patients were taking prasugrel or placebo, and of discontinuations due to prasugrel or placebo, did not differ significantly between the groups.

CONCLUSIONS

Among children and adolescents with sickle cell anemia, the rate of vaso-occlusive crisis was not significantly lower among those who received prasugrel than among those who received placebo. There were no significant between-group differences in the safety findings. (Funded by Daiichi Sankyo and Eli Lilly; ClinicalTrials.gov number, NCT01794000.).

Assessment of the clinical effects of cholesteryl ester transfer protein inhibition with evacetrapib in patients at high-risk for vascular outcomes: Rationale and design of the ACCELERATE trial

BACKGROUND

Potent pharmacologic inhibition of cholesteryl ester transferase protein by the investigational agent evacetrapib increases high-density lipoprotein cholesterol by 54% to 129%, reduces low-density lipoprotein cholesterol by 14% to 36%, and enhances cellular cholesterol efflux capacity. The ACCELERATE trial examines whether the addition of evacetrapib to standard medical therapy reduces the risk of cardiovascular (CV) morbidity and mortality in patients with high-risk vascular disease.

STUDY DESIGN

ACCELERATE is a phase 3, multicenter, randomized, double-blind, placebo-controlled trial. Patients qualified for enrollment if they have experienced an acute coronary syndrome within the prior 30 to 365 days, cerebrovascular accident, or transient ischemic attack; if they have peripheral vascular disease; or they have diabetes with coronary artery disease. A total of 12,092 patients were randomized to evacetrapib 130 mg or placebo daily in addition to standard medical therapy. The primary efficacy end point is time to first event of CV death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization. Treatment will continue until 1,670 patients reached the primary end point; at least 700 patients reach the key secondary efficacy end point of CV death, myocardial infarction, and stroke, and the last patient randomized has been followed up for at least 1.5 years.

CONCLUSIONS

ACCELERATE will establish whether the cholesteryl ester transfer protein inhibition by evacetrapib improves CV outcomes in patients with high-risk vascular disease.

Fingolimod-Associated Peripheral Vascular Adverse Effects

Fingolimod is the first oral disease-modifying drug approved for the treatment of multiple sclerosis. The drug is usually well tolerated, and common adverse effects include bradycardia, headache, influenza, diarrhea, back pain, increased liver enzyme levels, and cough. Fingolimod is thought to provide therapeutic benefit by preventing normal lymphocyte egress from lymphoid tissues, thus reducing the infiltration of autoaggressive lymphocytes into the central nervous system. However, because the drug acts on different sphingosine-1-phosphate receptors, it may induce several biological effects by influencing endothelial cell-cell adhesion, angiogenesis, vascular development, and cardiovascular function. We describe a patient with multiple sclerosis who, after 3 weeks of fingolimod administration, developed purplish blotches over the dorsal surface of the distal phalanges of the second and fifth digits and the middle phalanx of the fourth ray, itching, and edema on his left hand, without other evident clinical manifestations. When fingolimod therapy was discontinued, the clinical picture regressed within a few days but reappeared after a rechallenge test. Physicians should be aware of unexpected peripheral vascular adverse effects due to fingolimod use, and patients with vascular-based acropathies should be carefully screened and monitored when taking this drug.

Molecular and clinical characterization of glucokinase maturity-onset diabetes of the young (GCK-MODY) in Japanese patients

AIMS

To investigate the molecular and clinical characteristics of the largest series of Japanese patients with glucokinase maturity-onset diabetes of the young (GCK-MODY), and to find any features specific to Asian people.

METHODS

We enrolled 78 Japanese patients with GCK-MODY from 41 families (55 probands diagnosed at the age of 0-14 years and their 23 adult family members). Mutations were identified by direct sequencing or multiplex ligation-dependent probe amplification of all exons of the GCK gene. Detailed clinical and laboratory data were collected on the probands using questionnaires, which were sent to the treating physicians.　Data on current clinical status and HbA1c levels were also collected from adult patients.

RESULTS

A total of 35 different mutations were identified, of which seven were novel. Fasting blood glucose and HbA1c levels of the probands were ≤9.3 mmol/l and ≤56 mmol/mol (7.3%), respectively, and there was considerable variation in their BMI percentiles (0.4-96.2). In total, 25% of the probands had elevated homeostatic assessment of insulin resistance values, and 58.3% of these had evidence of concomitant Type 2 diabetes in their family. The HbA1c levels for adults were slightly higher, up to 61 mmol/mol (7.8%). The incidence of microvascular complications was low. Out of these 78 people with GCK-MODY and 40 additional family members with hyperglycaemia whose genetic status was unknown, only one had diabetic nephropathy.

CONCLUSIONS

The molecular and clinical features of GCK-MODY in Japanese people are similar to those of other ethnic populations; however, making a diagnosis of GCK-MODY was more challenging in patients with signs of insulin resistance.

Long-term outcomes of the Viabahn stent in the treatment of in-stent restenosis in the superficial femoral artery

There is no universally accepted method to treat in-stent restenosis (ISR) in the superficial femoral artery (SFA). It is hypothesized that using the Viabahn expandable polytetrafluoroethylene- covered stent to treat ISR may prevent tissue infiltration and intimal hyperplasia that leads to restenosis.

METHODS

We studied 22 patients (27 limbs) referred for treatment of severe ISR of the SFA. All patients were treated with the Viabahn stent implanted in the restenotic segments. We also analyzed several demographic, procedural, and laboratory parameters that could potentially be predictors of Viabahn restenosis.

RESULTS

Among patients treated, 63% had severe claudication and 37% had critical limb ischemia. Mean treated lesion length was 214.8 ± 87.2 mm, mean run-off score was 3.9 ± 2.8. Mean follow-up period was 21.8 ± 10.3 months. Ten patients (37%) developed Viabahn restenosis. The mean lesion length was 180.0 ± 107.9 mm in the restenosis group and 219.4 ± 78.9 mm in the no-restenosis group (P=.27). There was no significant difference between the two groups in the rest of demographic, procedural, and laboratory parameters. In 90%, restenosis occurred within the first 12 months and the remaining 10% occurred within 14 months. The mean time to restenosis was 6.2 ± 4.3 months. We observed no Viabahn ISR occurring after 14 month of follow-up.

CONCLUSION

The Viabahn stent can be used to treat ISR in the SFA, with favorable results of 63% primary patency at up to 3 years of follow-up. Analysis of multiple factors showed no association with restenosis occurrence. If the Viabahn remained patent for 14 months, the likelihood of restenosis was low.

Homocysteine lowering interventions for peripheral arterial disease and bypass grafts

BACKGROUND

Elevated plasma levels of the amino acid homocysteine (hyperhomocysteinaemia) are associated with narrowing or blocking of the arteries (atherosclerosis). Treatment to lower homocysteine levels has been shown to be both effective and cheap in healthy volunteers. However, the impact of reducing homocysteine levels on the progression of atherosclerosis and patency of the vessels after treatment for atherosclerosis is still unknown and forms the basis for this review. This is the second update of a review first published in 2002.

OBJECTIVES

To assess the effects of plasma homocysteine lowering therapy on the clinical progression of disease in people with peripheral arterial disease (PAD) and hyperhomocysteinaemia including, as a subset, those who have undergone surgical or radiological intervention.

SEARCH METHODS

For this update, the Cochrane Peripheral Vascular Disease Group Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched January 2013) and CENTRAL (2012, Issue 12). Trial databases were searched by the TSC (January 2013) for details of ongoing and unpublished studies. We also searched the reference lists of relevant articles.

SELECTION CRITERIA

Randomised trials in which participants with PAD and hyperhomocysteinaemia were allocated to either homocysteine lowering therapy or no treatment, including participants before and after surgical or radiological interventions.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the data. Information on adverse events was collected from the trials.

MAIN RESULTS

Two randomised trials with a total of 161 participants were included in this review. The studies did not report on mortality and rate of limb loss. One randomised trial with a total of 133 participants showed that there was a significant improvement in ankle brachial index (ABI) in participants who received folic acid compared with placebo (mean difference (MD) 0.07, 95% confidence interval (CI) 0.04 to 0.11, P < 0.001) and in participants who received 5-methyltetrahydrofolate (5-MTHF) versus placebo (MD 0.05, 95% CI 0.01 to 0.10, P = 0.009). A second trial with a total of 18 participants showed that there was no difference (P non-significant) in ABI in participants who received a multivitamin B supplement (mean ± SEM: 0.7 ± 01) compared with placebo (mean ± SEM: 0.8 ± 0.1). No major events were reported.

AUTHORS' CONCLUSIONS

Currently, no recommendation can be made regarding the value of treatment of hyperhomocysteinaemia in peripheral arterial disease. Further, well constructed trials are urgently required.

Patient knowledge of peripheral vascular disease in an outpatient setting: an Achilles heel?

Peripheral vascular disease (PVD) has numerous modifiable risk factors. This study aimed to establish patients' awareness of risk factors and causes of PVD and their understanding of mechanisms of secondary prevention. A prospective survey of awareness of PVD among patients attending a tertiary vascular clinic for management of peripheral vascular disease was undertaken. Institutional review board approval was granted. Statistical analysis was performed using SPSS version 18.0 software. There was a 100% response rate, with 97 participants (53 male). Seventeen patients (19%) reported an interval of greater than six months from the onset of symptoms to first seeking medical attention with their General Practitioner. Only 19 (20%) could correctly identify 3 or more risk factors for peripheral vascular disease. Patients have limited awareness of PVD and its consequences. Educational initiatives are needed to encourage patients to seek early medical attention and raise awareness of modifiable risk factors in the community.

Antiplatelet and anticoagulant drugs for prevention of restenosis/reocclusion following peripheral endovascular treatment

BACKGROUND

Peripheral arterial disease (PAD) is frequently treated by balloon angioplasty. Restenosis/reocclusion of the dilated segments occurs often, depending on length of occlusion, lower leg outflow, stage of disease and presence of cardiovascular risk factors. To prevent reocclusion, patients are treated with antithrombotic agents. This is an update of a review first published in 2005.

OBJECTIVES

To determine whether any antithrombotic drug is more effective in preventing restenosis or reocclusion after peripheral endovascular treatment, compared to another antithrombotic drug, no treatment, placebo or other vasoactive drugs.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched 14 February 2012) and CENTRAL (2012, Issue 1).

SELECTION CRITERIA

We selected randomised controlled trials (RCTs). Participants were patients with symptomatic PAD treated by endovascular revascularisation of the pelvic or femoropopliteal arteries. Interventions were anticoagulant, antiplatelet or other vasoactive drug therapy compared with no treatment, placebo or any other vasoactive drug. Clinical endpoints were reocclusion, restenosis, amputation, death, myocardial infarction, stroke, major bleeding and other side effects, such as minor bleeding, puncture site bleeding, gastrointestinal side effects and haematoma.

DATA COLLECTION AND ANALYSIS

We independently extracted and assessed details of the number of randomised patients, treatment, study design, patient characteristics and risk of bias. Analysis was based on intention-to-treat data. To examine the effects of outcomes such as reocclusion, restenosis, amputation and major bleeding, we computed odds ratios (OR) with 95% confidence intervals (CI) using a fixed-effect model.

MAIN RESULTS

Twenty-two trials with a total of 3529 patients are included (14 in the original review and a further eight in this update). For the majority of comparisons, only one trial was available so results were rarely combined in meta-analyses. Individual trials were generally small and risk of bias was often unclear due to limitations in reporting. Three trials reported on drug versus placebo/control; results were consistently available for a maximum follow-up of only six months. At six months post intervention, a statistically significant reduction in reocclusion was found for high-dose acetylsalicylic acid (ASA) combined with dipyridamole (DIP) (OR 0.40, 95% CI 0.19 to 0.84), but not for low-dose ASA combined with DIP (OR 0.69, 95% CI 0.44 to 1.10; P = 0.12) nor in major amputations for lipo-ecraprost (OR 0.89, 95% CI 0.44 to 1.80). The remaining trials compared different drugs; results were more consistently available for a longer period of 12 months. At 12 months post intervention, no statistically significant difference in reocclusion/restenosis was detected for any of the following comparisons: high-dose ASA versus low-dose ASA (OR 0.98, 95% CI 0.64 to 1.48; P = 0.91), ASA/DIP versus vitamin K antagonists (VKA) (OR 0.65, 95% CI 0.40 to 1.06; P = 0.08), clopidogrel and aspirin versus low molecular weight heparin (LMWH) plus warfarin (OR 0.31, 95% CI 0.06 to 1.68; P = 0.18), suloctidil versus VKA: reocclusion (OR 0.59, 95% CI 0.20 to 1.76; P = 0.34), restenosis (OR 1.87, 95% CI 0.66 to 5.31; P = 0.24) and ticlopidine versus VKA (OR 0.71, 95% CI 0.37 to 1.36; P = 0.30). Treatment with cilostazol resulted in statistically significantly fewer reocclusions than ticlopidine (OR 0.32, 95% CI 0.13 to 0.76; P = 0.01). Compared with aspirin alone, LMWH plus aspirin significantly decreased occlusion/restenosis (by up to 85%) in patients with critical limb ischaemia (OR 0.15, 95% CI 0.06 to 0.42; P = 0.0003) but not in patients with intermittent claudication (OR 1.73, 95% CI 0.97 to 3.08; P = 0.06) and batroxobin plus aspirin reduced restenosis in diabetic patients (OR 0.28, 95% CI 0.13 to 0.60). Data on bleeding and other potential gastrointestinal side effects were not consistently reported, although there was some evidence that high-dose ASA increased gastrointestinal side effects compared with low-dose ASA, that clopidogrel and aspirin resulted in fewer major bleeding episodes compared with LMWH plus warfarin, and that abciximab resulted in more severe bleeding episodes.

AUTHORS' CONCLUSIONS

There is limited evidence suggesting that restenosis/reocclusion at six months following peripheral endovascular treatment is reduced by use of antiplatelet drugs compared with placebo/control, but associated information on bleeding and gastrointestinal side effects is lacking. There is also some evidence of variation in effect according to different drugs with cilostazol reducing reocclusion/restenosis at 12 months compared with ticlopidine and both LMWH and batroxobin combined with aspirin appearing beneficial compared with aspirin alone. However, available trials are generally small and of variable quality and side effects of drugs are not consistently addressed. Further good quality, large-scale RCTs, stratified by severity of disease, are required.

The endothelin receptor antagonist bosentan improves peripheral endothelial function in patients with type 2 diabetes mellitus and microalbuminuria: a randomised trial

AIMS/HYPOTHESIS

Endothelial dysfunction is important in the development of vascular complications in diabetes. Patients with type 2 diabetes have increased production of the vasoconstrictor and pro-inflammatory peptide, endothelin-1. Short-term intra-arterial administration of endothelin antagonists improves endothelium-dependent vasodilatation in patients with type 2 diabetes. We tested the hypothesis that oral administration of the dual endothelin receptor antagonist, bosentan, improves peripheral endothelial function in patients with type 2 diabetes and microalbuminuria.

METHODS

This placebo-controlled and double-blind study was performed on 46 patients with type 2 diabetes and microalbuminuria (urine albumin/creatinine ratio >3 mg/mmol) at a medical university department. Patients were randomised to bosentan, 125 mg two times per day (n = 28), or placebo (n = 28) for 4 weeks. The computer-generated randomisation code was kept in sealed envelopes. Patients and people doing examinations or assessing outcomes were blinded. The primary endpoint was change in microvascular endothelium-dependent vasodilatation, based on change in digital reactive hyperaemia index. The secondary endpoint was change in brachial artery flow-mediated vasodilatation.

RESULTS

Reactive hyperaemia index increased from 1.73 ± 0.43 (mean ± SD) at baseline to 2.08 ± 0.59 at follow-up (p < 0.05) in the bosentan group (n = 22), but did not change in the placebo group (1.84 ± 0.49 to 1.87 ± 0.47; n = 24). The change in reactive hyperaemia index from baseline was greater in the bosentan group than in the placebo group (p < 0.05). Nitroglycerine-induced digital hyperaemia was not affected. Brachial artery flow-mediated vasodilatation and blood pressure did not change during treatment.

CONCLUSIONS/INTERPRETATION

Oral treatment of 4 weeks duration with the dual endothelin receptor antagonist, bosentan, improves peripheral endothelial function in patients with type 2 diabetes and microalbuminuria.

The ulcerated leg: when to revascularize

The role of peripheral arterial disease in ulcerated diabetic feet has long been underestimated. Progressive claudication, rest pain and the extent of irreversible tissue loss have frequently been indications for revascularization for neuroischaemic ulcers in diabetic patients. These typical ischaemic symptoms are warning signs that are less frequent in diabetic individuals with ischaemia than those without diabetes. Consequently, 30-50% of individuals with diabetes and foot ulcers already have gangrene at admission and are therefore often considered unsuitable for revascularization. Furthermore, the healing of a neuroischaemic ulcer is worsened by microvascular dysfunction, causing arteriovenous shunting, capillary ischaemia, leakage and venous pooling. Therefore, the threshold of revascularizing neuroischaemic ulcers should be lower than that of purely ischaemic ulcers. Comorbidity, ulcer characteristics and infection affect the decision as to when to intervene, as do the severity and extent of occlusive arterial lesions. The window of opportunity for vascular intervention in the neuroischaemic diabetic foot should not be missed, and the need for early vascular intervention as an integrated part of a strategy to achieve healing should be emphasized. Noninvasive vascular testing should be performed on all individuals with an ulcerated diabetic foot. The arterial tree should be imaged if noninvasive tests indicate ischaemia or when mild or questionable ischaemia is diagnosed and conservative treatment does not promote ulcer healing in 6 weeks. Revascularization should be performed whenever feasible to repair distal perfusion to achieve ulcer healing.

Diabetic foot and PAD: the endovascular approach

Diabetic foot ulceration (DFU) is recognized as one of the most serious complications of diabetes. Active revascularisation plays a crucial role in achieving ulcer healing. Non-surgical, minimally invasive, revascularisation options for DFU have expanded over the last decade and have become a prominent tool to prevent amputation. Endovascular treatment of arterial DFU lesions is mainly concentrated in the below-the-knee arteries. The outcome of both open surgery and endovascular treatment is broadly spoken the same for the endpoints ulcer healing and limb salvage and is between 78% and 85%. The choice between endovascular treatment and open surgery should always be the outcome of a team discussion. Local expertise plays an important role in these discussions. In many institutions, the endovascular approach has currently become the first choice treatment option. The revascularisation of below-the-knee vessels needs experienced hands, team discussion and the right set of devices. Centralisation in DFU centres is therefore probably the best guaranty for the best outcome.

Epidemiological evidence for new frequency weightings of hand-transmitted vibration

This paper provides an overview of the exposure-response relationship for the vascular component of the hand-arm vibration syndrome, called vibration-induced white finger (VWF). Over the past two decades, several epidemiological studies have shown a poor agreement between the risk for VWF observed in various occupational groups and that predicted by models included in annexes to International Standard ISO 5349 (ISO 5349:1986, ISO 5349-1:2001). Either overestimation or underestimation of the occurrence of VWF have been reported by investigators. It has been argued that the current ISO frequency-weighting curve for hand-transmitted vibration, which assumes that vibration-induced adverse health effects are inversely related to the frequency of vibration between 16 and 1250 Hz, may be unsuitable for the assessment of VWF. To investigate this issue, a prospective cohort study was carried out to explore the performance of four alternative frequency weightings for hand-transmitted vibration to predict the incidence of VWF in groups of forestry and stone workers. The findings of this study suggested that measures of vibration exposure which give relatively more weight to intermediate and high frequency vibration produced better predictions of the incidence of VWF than that obtained with the frequency weighting currently recommended in International Standard ISO 5349-1:2001.

Intensive statin therapy for Indians: Part-I. Benefits

The underlying disorder in the vast majority of cases of cardiovascular disease (CVD) is atherosclerosis, for which low-density lipoprotein cholesterol (LDL-C) is recognized as the first and foremost risk factor. HMG-CoA reductase inhibitors, popularly called statins, are highly effective and remarkably safe in reducing LDL-C and non-HDL-C levels. Evidence from clinical trials have demonstrated that statin therapy can reduce the risk of myocardial infarction (MI), stroke, death, and the need for coronary artery revascularization procedures (CARPs) by 25-50%, depending on the magnitude of LDL-C lowering achieved. Benefits are seen in men and women, young and old, and in people with and without diabetes or prior diagnosis of CVD. Clinical trials comparing standard statin therapy to intensive statin therapy have clearly demonstrated greater benefits in CVD risk reduction (including halting the progression and even reversing coronary atherosclerosis) without any corresponding increase in risk. Numerous outcome trials of intensive statin therapy using atorvastatin 80 mg/d have demonstrated the safety and the benefits of lowering LDL-C to very low levels. This led the USNCEP Guideline Committee to standardize 40 mg/dL as the optimum LDL-C level, above which the CVD risk begins to rise. Recent studies have shown intensive statin therapy can also lower CVD events even in low-risk individuals with LDL-C <110 mg/dL. Because of the heightened risk of CVD in Asian Indians, the LDL-C target is set at 30 mg/dL lower than that recommended by NCEP. Accordingly, the LDL-C goal is < 70 mg/dL for Indians who have CVD, diabetes, metabolic syndrome, or chronic kidney disease. Intensive statin therapy is often required in these populations as well as others who require a > or = 50% reduction in LDL-C. Broader acceptance of this lower LDL-C targets and its implementation could reduce the CVD burden in the Indian population by 50% in the next 25 years. Clinical trial data support an extremely favorable benefit-to-risk ratio of intensive statin therapy with some but not all statins. Atorvastatin 80 mg/d is 100 times safer than aspirin 81 mg/d and 10 times safer than diabetic medications. Intensive statin therapy is more effective and safe compared to intensive control of blood sugar or blood pressure in patients with diabetes.

[Prevention and treatment of extremity vascular ischemic disease]

Extremitovascular ischemic disease (peripheral arterial disease of extremities - PAD) is an important manifestation of systemic atherosclerosis and other arterial diseases of vascular system. The lower the anklebrachial pressure index, the greater the risk of serious cardiovascular events (e.g., acute myocardial infarction, stroke). Prevention and treatment ofextremitovascular disease is discussed in this article.

Brewing the right cocktail for radial intervention

Radial access angioplasty has increased in popularity worldwide due to its decrease of access site complications, early patient mobility, patient comfort and lower costs. In a minority of patients, radial artery occlusion and radial artery spasm occurs. Because of the dual blood supply to the hand, radial artery occlusion is not associated with major clinical sequelae but prevention is important. Radial artery spasm rarely leads to serious vascular complications but can cause patient discomfort and can result in prolonging or failure of the procedure. Pharmacological and non-pharmacological strategies have been evaluated to prevent radial artery occlusion and radial artery spasm. A number of pharmacological 'cocktails' have been successfully tested but there is currently no agreement on the optimal combination of agents. In order to evaluate the best strategy to prevent radial artery occlusion and radial artery spasm we reviewed the relevant studies to date. From these studies it is clear that a 'cocktail' of agents should be given before transradial coronary angiography or angioplasty. A combination of heparin, nitroglycerin and verapamil is associated with the best preventive outcome.

Transradial coronary angiography in children and adolescents

Radial arterial access for coronary angiography is widely used in adults. We aimed to determine its safety and feasibility in pediatric practice. Twelve children and adolescents post cardiac transplantation (13 procedures) were studied. The radial artery was cannulated with a 5-Fr sheath after subcutaneous injection of 2% lidocaine. A mixture of verapamil, heparin, and isosorbide dinitrate was administered to reduce spasm. Selective coronary angiograms were obtained using Judkin or Amplatz coronary catheters. Following the procedure, hemostasis was achieved with a TR Band. Median age was 16.7 years (range, 12.1-18.8 years), and median weight 55.2 kg (range, 39-81 kg). Seventy percent of cases were under local anesthetic. Radial access was successful in 85%. Severe arterial spasm led to abandonment in one and failure to complete the study adequately in two patients. No vascular complications occurred. On direct questioning all but one patient preferred the radial approach. We conclude that the radial approach to coronary angiography is safe and feasible in children and adolescents. Radial artery spasm can be a problem and difficult to reverse once it occurs, leading to procedure abandonment. However, the technique is successful in the majority of cases and provides an alternative approach to arterial access in this age group.

[Peripheral arterial disease: secondary prevention, medical therapy, revascularization]

Patients with peripheral arterial disease have a high risk of cardiovascular morbidity and mortality. Thus, antiplatelet drugs, antidiabetic, antihypertensive and antilipemic agents should be administered early on. Smoking cessation has to be encouraged and supported. In case of significant reduction of walking distance with impaired quality of life structured and supervised exercise training as well as vasoactive substances have to be offered. If technically feasible and critically discussed with the patient revascularization procedures of the aorto-iliac and the femoro-popliteal segment may be performed. In patients with critical limb ischemia, all options for vascularisation have to be utilized as the main goal is limb salvage. As medication, only prostanoids have to be considered.

Diabetic patients: epidemiology and global impact

Definition of the exact epidemiology and the global impact of diabetes is not easy, being strictly related to the availability of data in developing countries and to the use in the existing population-based investigations of common criteria for the diagnosis and definition of diabetes. According to the World Health Organization (WHO) the total number of people with diabetes was 171 million in 2000, and is projected to rise up to 366 million in 2030. The true prevalence of peripheral arterial disease (PAD) in people with diabetes has been difficult to determine, as most patients are asymptomatic, many do not report their symptoms, screening modalities have not been uniformly agreed upon, and pain perception may be blunted by the presence of peripheral neuropathy. Population-based studies, using a validated and reproducible test, have revealed a prevalence of PAD in people with diabetes to be up to 30%. Among people with diabetes, the annual incidence of developing a foot ulcer ranges from 1% to 4.1% and the prevalence ranges from 4% to 10%, which suggests that the lifetime incidence may be as high as 25%. Foot ulcer associated to PAD requires revascularization, although it is generally considered that the outcome in those people is inferior to that in non-diabetic patients. In summary, the increasing worldwide diabetes prevalence will inevitably result in increasing proportions of deaths from cardiovascular disease, as well as in increased prevalence and associated consequences of other complications of diabetes. As suggested by WHO, a concerted, global initiative is required to address the diabetes epidemic.

The prevention of progression of arterial disease and diabetes (POPADAD) trial: factorial randomised placebo controlled trial of aspirin and antioxidants in patients with diabetes and asymptomatic peripheral arterial disease

OBJECTIVE

To determine whether aspirin and antioxidant therapy, combined or alone, are more effective than placebo in reducing the development of cardiovascular events in patients with diabetes mellitus and asymptomatic peripheral arterial disease.

DESIGN

Multicentre, randomised, double blind, 2x2 factorial, placebo controlled trial.

SETTING

16 hospital centres in Scotland, supported by 188 primary care groups.

PARTICIPANTS

1276 adults aged 40 or more with type 1 or type 2 diabetes and an ankle brachial pressure index of 0.99 or less but no symptomatic cardiovascular disease.

INTERVENTIONS

Daily, 100 mg aspirin tablet plus antioxidant capsule (n=320), aspirin tablet plus placebo capsule (n=318), placebo tablet plus antioxidant capsule (n=320), or placebo tablet plus placebo capsule (n=318).

MAIN OUTCOME MEASURES

Two hierarchical composite primary end points of death from coronary heart disease or stroke, non-fatal myocardial infarction or stroke, or amputation above the ankle for critical limb ischaemia; and death from coronary heart disease or stroke.

RESULTS

No evidence was found of any interaction between aspirin and antioxidant. Overall, 116 of 638 primary events occurred in the aspirin groups compared with 117 of 638 in the no aspirin groups (18.2% v 18.3%): hazard ratio 0.98 (95% confidence interval 0.76 to 1.26). Forty three deaths from coronary heart disease or stroke occurred in the aspirin groups compared with 35 in the no aspirin groups (6.7% v 5.5%): 1.23 (0.79 to 1.93). Among the antioxidant groups 117 of 640 (18.3%) primary events occurred compared with 116 of 636 (18.2%) in the no antioxidant groups (1.03, 0.79 to 1.33). Forty two (6.6%) deaths from coronary heart disease or stroke occurred in the antioxidant groups compared with 36 (5.7%) in the no antioxidant groups (1.21, 0.78 to 1.89).

CONCLUSION

This trial does not provide evidence to support the use of aspirin or antioxidants in primary prevention of cardiovascular events and mortality in the population with diabetes studied.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN53295293.

Predisease biological markers: early diagnosis and prevention of arterial hypertension

This review examines 2 potentially important morbid changes that may precede the onset of hypertension-capillary rarefaction (CR) and large artery rigidity (LAR). The mechanisms responsible for CR, currently measured in the skin microcirculation, as well those responsible for LAR, have yet to be fully delineated. Nor has the duration been determined of the latent period between the occurrence of these lesions and the onset of blood pressure elevation. It has been known for 2 decades that, because of the kidney's relatively rigid capsule, alterations in the abundant postglomerular microcirculation network (which can accommodate circa 80% of total renal blood flow) can lead to endothelial plasma leakage. Even a small amount of plasma leakage can increase interstitial pressure and lead to capillary collapse and CR. Simultaneously, or at a later time, these alterations could have an impact on the reflection wave profile in the thoracic aorta and, via abnormal endothelial proliferation and other vascular effects, give rise to LAR. Nonpharmacologic and/or pharmacologic interventions have been shown to exert positive effects on CR and/or LAR. Recent studies have demonstrated the beneficial actions of a bradykinin B2-receptor antagonist (HOE140) in the spontaneously hypertensive rat, the classic rat model for essential hypertension. The fact that CR and LAR both precede blood pressure elevation could serve as a basis for designing strategies to prevent hypertension from occurring. Because modern tools capable of measuring CR and LAR noninvasively have been developed, it should soon be feasible to identify these 2 prehypertension markers in individual patients.

Cardiovascular risk factor management is poorer in diabetic patients with undiagnosed peripheral arterial disease than in those with known coronary heart disease or cerebrovascular disease. Results of a nationwide study in tertiary diabetes centres

AIMS

To assess whether patients with Type 2 diabetes mellitus and unrecognized peripheral arterial disease (PAD), detected by the ankle-brachial index (ABI), have poorer cardiovascular risk factor management (CVRFs) and receive fewer medications than patients previously diagnosed with coronary heart disease (CHD) or cerebrovascular disease (CVD).

METHODS

In 31 diabetes centres throughout Spain, 1303 patients with Type 2 diabetes mellitus were screened for PAD using the ABI. Patient history of CHD and CVD and treatment and control of CVRFs were recorded.

RESULTS

Forty-one patients had an ABI > 1.30 and were excluded, leaving 1262 patients (age 65.3 +/- 7.7 years) for the study. Of those screened, 790 patients had a normal ABI (ABI > 0.9) and no known history of CHD or CVD (no CHD/CVD/PAD group), 194 had unrecognized PAD (ABI < or = 0.9) with no known history of CHD or CVD (undiagnosed PAD group) and 278 had a known history of CHD and/or CVD (CHD/CVD group). The undiagnosed PAD group had higher low-density lipoprotein (LDL) cholesterol (2.9 +/- 0.83 vs. 2.4 +/- 0.84 mmol/l; P < 0.001) and systolic blood pressure (150 +/- 20 vs. 145 +/- 21 mmHg; P < 0.001) compared with the CHD/CVD group. They were less likely to take statins (56.9 vs. 71.6%; P < 0.001), anti-hypertensive agents (75.9 vs. 90.1%, P = 0.001), and anti-platelet agents (aspirin, 28.7 vs. 57.2%; P < 0.001; clopidogrel, 5.6 vs. 20.9%; P < 0.001) and more likely to smoke (21.0 vs. 9.2%; P < 0.001). Higher LDL in the undiagnosed PAD group was associated with the underutilization of statins.

CONCLUSIONS

Measurement of ABI detected a significant number of patients with PAD, who did not have CHD or CVD, but whose CVRFs were under treated and poorly controlled compared with subjects with CHD and/or CVD.

Intra-arterial vitamin C prevents endothelial dysfunction caused by ischemia-reperfusion

OBJECTIVE

Ischemia-reperfusion (IR) injury causes tissue injury and endothelial dysfunction. There is evidence that oxidative stress plays an important role.

METHODS

We tested if IR-induced endothelial dysfunction could be prevented by administration of the antioxidant vitamin C. Twenty-six healthy male subjects and eight male patients with peripheral arterial disease (PAD) were enrolled in this randomised placebo-controlled study. Forearm blood flow (FBF) measurements in response to the vasodilators acetylcholine (ACh; endothelium-dependent agonist) or nitroglycerin (NTG; endothelium-independent) were performed before and after forearm ischemia for 20 min. FBF responses were reassessed during reperfusion with intra-arterial co-administration of 24 mg/min vitamin C or placebo. In six volunteers responses to the NO-synthase inhibitor N-monomethyl-L-arginine (L-NMMA) were also assessed before and after ischemia with and without vitamin C.

RESULTS

ACh-induced vasodilation was blunted in subjects receiving placebo after reperfusion (p<0.05 versus baseline). Administration of vitamin C completely prevented impaired responsiveness. NTG-induced vasodilation was not affected by reperfusion or vitamin C. This finding was consistent in patients with PAD and impaired endothelial function, where local vitamin C infusion restored FBF reactivity to ACh before and after IR injury (p<0.05 versus baseline). Again, NTG-induced vasodilation was not affected. Blunted L-NMMA responses seen during reperfusion could be completely reversed by vitamin C.

CONCLUSIONS

Our data indicate that IR-induced vascular injury can be prevented by administration of antioxidants.