Randolph Guzman

Antithrombotic Therapy in Peripheral Artery Disease

BACKGROUNDnThis guideline focuses on antithrombotic drug therapies for primary and secondary prevention of cardiovascular disease as well as for the relief of lower-extremity symptoms and critical ischemia in persons with peripheral arterial disease (PAD).nnnMETHODSnThe methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.nnnRESULTSnThe most important of our 20 recommendations are as follows. In patients aged ≥ 50 years with asymptomatic PAD or asymptomatic carotid stenosis, we suggest aspirin (75-100 mg/d) over no therapy (Grade 2B) for the primary prevention of cardiovascular events. For secondary prevention of cardiovascular disease in patients with symptomatic PAD (including patients before and after peripheral arterial bypass surgery or percutaneous transluminal angioplasty), we recommend long-term aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 1A). We recommend against the use of warfarin plus aspirin in patients with symptomatic PAD (Grade 1B). For patients undergoing peripheral artery percutaneous transluminal angioplasty with stenting, we suggest single rather than dual antiplatelet therapy (Grade 2C). For patients with refractory claudication despite exercise therapy and smoking cessation, we suggest addition of cilostazol (100 mg bid) to aspirin (75-100 mg/d) or clopidogrel (75 mg/d) (Grade 2C). In patients with critical limb ischemia and rest pain unable to undergo revascularization, we suggest the use of prostanoids (Grade 2C). In patients with acute limb ischemia due to acute thrombosis or embolism, we recommend surgery over peripheral arterial thrombolysis (Grade 1B).nnnCONCLUSIONSnRecommendations continue to favor single antiplatelet therapy for primary and secondary prevention of cardiovascular events in most patients with asymptomatic PAD, symptomatic PAD, and asymptomatic carotid stenosis. Additional therapies for relief of limb symptoms should be considered only after exercise therapy, smoking cessation, and evaluation for peripheral artery revascularization.

Potent Antihypertensive Action of Dietary Flaxseed in Hypertensive Patients

Flaxseed contains &ohgr;-3 fatty acids, lignans, and fiber that together may provide benefits to patients with cardiovascular disease. Animal work identified that patients with peripheral artery disease may particularly benefit from dietary supplementation with flaxseed. Hypertension is commonly associated with peripheral artery disease. The purpose of the study was to examine the effects of daily ingestion of flaxseed on systolic (SBP) and diastolic blood pressure (DBP) in peripheral artery disease patients. In this prospective, double-blinded, placebo-controlled, randomized trial, patients (110 in total) ingested a variety of foods that contained 30 g of milled flaxseed or placebo each day over 6 months. Plasma levels of the &ohgr;-3 fatty acid &agr;-linolenic acid and enterolignans increased 2- to 50-fold in the flaxseed-fed group but did not increase significantly in the placebo group. Patient body weights were not significantly different between the 2 groups at any time. SBP was ≈10 mm Hg lower, and DBP was ≈7 mm Hg lower in the flaxseed group compared with placebo after 6 months. Patients who entered the trial with a SBP ≥140 mm Hg at baseline obtained a significant reduction of 15 mm Hg in SBP and 7 mm Hg in DBP from flaxseed ingestion. The antihypertensive effect was achieved selectively in hypertensive patients. Circulating &agr;-linolenic acid levels correlated with SBP and DBP, and lignan levels correlated with changes in DBP. In summary, flaxseed induced one of the most potent antihypertensive effects achieved by a dietary intervention.

Dietary Flaxseed Independently Lowers Circulating Cholesterol and Lowers It beyond the Effects of Cholesterol-Lowering Medications Alone in Patients with Peripheral Artery Disease

BACKGROUNDnDietary flaxseed lowers cholesterol in healthy subjects with mild biomarkers of cardiovascular disease (CVD).nnnOBJECTIVEnThe aim was to investigate the effects of dietary flaxseed on plasma cholesterol in a patient population with clinically significant CVD and in those administered cholesterol-lowering medications (CLMs), primarily statins.nnnMETHODSnThis double-blind, randomized, placebo-controlled trial examined the effects of a diet supplemented for 12 mo with foods that contained either 30 g of milled flaxseed [milled flaxseed treatment (FX) group; n = 58] or 30 g of whole wheat [placebo (PL) group; n = 52] in a patient population with peripheral artery disease (PAD). Plasma lipids were measured at 0, 1, 6, and 12 mo.nnnRESULTSnDietary flaxseed in PAD patients resulted in a 15% reduction in circulating LDL cholesterol as early as 1 mo into the trial (P = 0.05). The concentration in the FX group (2.1 ± 0.10 mmol/L) tended to be less than in the PL group (2.5 ± 0.2 mmol/L) at 6 mo (P = 0.12), but not at 12 mo (P = 0.33). Total cholesterol also tended to be lower in the FX group than in the PL group at 1 mo (11%, P = 0.05) and 6 mo (11%, P = 0.07), but not at 12 mo (P = 0.24). In a subgroup of patients taking flaxseed and CLM (n = 36), LDL-cholesterol concentrations were lowered by 8.5% ± 3.0% compared with baseline after 12 mo. This differed from the PL + CLM subgroup (n = 26), which increased by 3.0% ± 4.4% (P = 0.030) to a final concentration of 2.2 ± 0.1 mmol/L.nnnCONCLUSIONSnMilled flaxseed lowers total and LDL cholesterol in patients with PAD and has additional LDL-cholesterol-lowering capabilities when used in conjunction with CLMs. This trial was registered at clinicaltrials.gov as NCT00781950.

Daily non-soy legume consumption reverses vascular impairment due to peripheral artery disease.

OBJECTIVEnPeripheral artery disease (PAD) results from a decrease in blood flow to the limbs due to the presence of atherosclerotic plaque. It has been reported that isoflavones isolated from soybeans reduce arterial stiffness, a component of atherosclerotic disease. This study examined the effect of consuming whole legumes (non-soy) on arterial function in humans with PAD.nnnMETHODSnTwenty-six individuals with PAD consumed ½ cup/day cooked legumes (beans, peas, lentils, chickpeas) daily for 8 weeks. Measurements of circulating factors and vascular function at baseline and study conclusion were compared.nnnRESULTSnNo changes in were detected relative to baseline values for most parameters. Total and LDL-cholesterol were reduced by 5.0% and 8.7%, respectively. The ankle-brachial index (ABI) showed a 5.5% increase. Changes in ABI and LDL-cholesterol did not correlate. Serum markers of endothelial dysfunction and inflammation were unchanged, but short-chain acylcarnitine concentrations were significantly decreased.nnnCONCLUSIONSnA legume-rich diet can elicit major improvements in arterial function and serum cholesterol in the absence of changes in either body mass or blood pressure, although the improvements in vascular function and serum lipids were unrelated. Although the positive results obtained with this dietary intervention were not explained by biomarkers of endothelial function and inflammation, altered acylcarnitine levels indicate an improvement in skeletal muscle metabolism due to enhanced tissue perfusion.

Dietary Flaxseed Reduces Central Aortic Blood Pressure Without Cardiac Involvement but Through Changes in Plasma Oxylipins.

In the year-long FlaxPAD clinical trial (Flaxseed for Peripheral Artery Disease), dietary flaxseed generated a powerful reduction in brachial systolic and diastolic blood pressure in patients with peripheral artery disease. Oxylipins were implicated as potential mechanistic mediators. However, the ability of flaxseed to impact central aortic hypertension, arterial stiffness, or cardiac performance was not investigated. Additionally, the relationship between central blood pressure (cBP) and oxylipins was not elucidated. Therefore, radial tonometry and pulse wave analysis were used to measure cBP and cardiac function in the FlaxPAD population (n=62). Plasma oxylipins were analyzed with high-performance liquid chromatography mass spectrometry. In patients with high blood pressure at baseline, the average decrease in central systolic and diastolic blood pressures versus placebo was 10 and 6 mmu2009Hg, respectively. Flaxseed did not significantly impact augmentation index or other cardiac function indices. Alternatively, the data support several specific oxylipins as potential mediators in the antihypertensive properties of flaxseed. For example, every 1 nmol/L increase in plasma 16-hydroxyeicosatetraenoic acid increased the odds of higher central systolic and diastolic blood pressures by 12- and 9-fold, respectively. Every 1 nmol/L increase in plasma thromboxane B2 and 5,6-dihydroxyeicosatrienoic acid increased the odds of higher cBP by 33- and 9-fold, respectively. Flaxseed induced a decrease in many oxylipins, which corresponded with a reduced risk of elevated cBP. These data extend the antihypertensive properties of flaxseed to cBP without cardiac involvement but rather through oxylipins. This study provides further support for oxylipins as therapeutic targets in hypertension. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00781950.

Carotid endarterectomy results in the early years of practice

BACKGROUNDnNewly qualified surgeons, as well as their referring physicians, are understandably anxious when dangerous surgery is contemplated. Carotid endarterectomy (CEA), which requires a low morbidity/mortality rate to be successful, is especially problematic in this realm. There is a paucity of literature indicating the results that can be expected when a less-experienced surgeon is asked to perform this procedure. As the volume of CEA surgery is expected to decrease in the future with improvements in endovascular techniques, there will be fewer highly experienced CEA surgeons around.nnnMETHODSnWe studied the first consecutive, prospectively recorded 100 CEAs performed by each of two newly qualified surgeons (200 total) between January 1993 and May 1998. Standard technique was used and all cases were done under general anesthesia. The only difference in technique was the more liberal use of shunting and protamine by one individual.nnnRESULTSnThere were no significant differences in the patient demographics between the two surgeons. Seventy-five percent of the cases harbored symptomatic stenoses. An overall combined stroke/mortality rate of 5.5% was observed. The rate in those operated on for symptomatic stenosis (n = 150) was 6% while it was 4% for those with asymptomatic pathology. There were no significant differences in outcome between the two surgeons. The average stroke/mortality rate in the first 50 cases for each surgeon was 7%, as opposed to 4% for the second 50 cases.nnnCONCLUSIONSnThese data indicate that less-experienced individuals can perform this procedure with good results.

Female Sex Does Not Influence 30-Day Stroke and Mortality Rates after Carotid Endarterectomy

BACKGROUNDnSex-based differences in outcomes for the treatment of carotid arterial disease remains a controversial topic. The main objective of this study was to determine if gender differences influence 30-day stroke and mortality rates after carotid endarterectomy (CEA) in a large series of patients.nnnMETHODSnThis is a retrospective study of all patients undergoing endarterectomy performed by a single surgeon between January 1, 1993 and December 15, 2010. The analysis included data from 1,046 CEAs (683 men and 363 women).nnnRESULTSnThere were no differences found in 30-day stroke, death, or combined stroke and death rates between women and men. The 30-day stroke rate was 1.6% for women and 1.8% for men (P = 0.98), with no significant differences between asymptomatic patients (1.7% for women vs. 1.2% for men; P = 0.70) or symptomatic patients (1.6% for women vs. 2.1% for men; P = 0.74). The 30-day mortality rate was 0.8% for women and 0.9% for men (P = 0.85) with no significant differences between asymptomatic patients (0.8% for women vs. 1.2% for men; P = 0.77) and symptomatic patients (0.8% for women vs. 0.7% for men; Pxa0= 0.84). There was a similar low risk for the combined outcome of stroke and death (1.9% for women vs. 2.2% for men; P = 0.92), with no differences between asymptomatic patients (1.7% for women vs. 1.6% for men; P = 0.89) or symptomatic patients (2.1% for women vs. 2.5% for men; P = 0.84).nnnCONCLUSIONSnFemale sex does not influence 30-day stroke and mortality rates after CEA, regardless of preoperative symptom status.

Vascular prostheses for open surgery

Abstract: The chapter discusses the advantages and limitations of arterial prostheses (or vascular grafts) in terms of their biocompatibility, biofunctionality and biostability. Criteria for biomaterials selection and prosthesis design that have enabled patients to recover more rapidly without any device-related complications are reviewed, and developments are considered that may lead to future improvements in healing and clinical outcomes for the next generation of vascular prostheses.

The Effects of Dietary Flaxseed on Cardiac Arrhythmias and Claudication in Patients with Peripheral Arterial Disease

Patients with peripheral artery disease (PAD) are at increased risk for cardiovascular events, and higher susceptibility for cardiac arrhythmias may be involved. The objectives of this double-blinded randomized controlled FLAX-PAD trial were to determine whether daily consumption of a diet supplemented with 30 g of milled flaxseed (or placebo) over 1 year by PAD patients has effects on the prevalence of cardiac arrhythmias and exercise capacity. Cardiac arrhythmias were assessed on a cardiac stress test and at rest. At baseline, the PAD patients had a high incidence of cardiac arrhythmias (48% in the flaxseed group and 32% in the placebo group). After 1 year, the presence of cardiac arrhythmias in the flaxseed group decreased by 2% and increased by 12% in the placebo group (P > 0.05). Electrocardiographic variables (P, PR, QRS, QT, and QTc) did not change in either group during the trial. Patients from both groups improved initial and absolute claudication distances but the intergroup difference was also not statistically significant. In summary, the prevalence of cardiac arrhythmias and physical capacity trended in a positive direction for patients ingesting flaxseed but either a larger sample size or a longer intervention with flaxseed may be required to show statistically significant differences.

Randomized controlled trial to evaluate the effect of canola oil on blood vessel function in peripheral arterial disease: rationale and design of the Canola-PAD Study

License. The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited. Information on how to request permission may be found at: http://www.dovepress.com/permissions.php Open Access Journal of Clinical Trials 2014:6 117–125 Open Access Journal of Clinical Trials Dovepress