Relationship Between Intermittent Claudication, Inflammation, Thrombosis, and Recurrent Cardiac Events Among Survivors of Myocardial Infarction

Risk Factors, Use of Revascularization, and Outcomes in Young Adults With ST-Elevation Myocardial Infarction

The incidence of acute myocardial infarction is increasing in younger age groups, with differences in treatment and outcomes based on gender. ST-elevation myocardial infarction (STEMI) in young adults, however, is incompletely understood as most of the current studies were performed in homogenous populations, did not focus on STEMI, and lack direct comparisons with older adults. We performed a retrospective observational study using the Statewide Planning And Research Cooperative System for all admissions in New York State with a principal diagnosis of STEMI from 2011 to 2018. There were 58,083 STEMIs with the majority being male (68.2%) and non-Hispanic White (64.8%), with an average age of 63.9 ± 13.9 years. Of these, 8,494 (14.6%) occurred in patients aged <50 years. The proportion of STEMIs in women increased with age, from 19.2% in the <50-year-old age group to 48.9% in the ≥70-year-old age group. Young adults with STEMI had greater prevalence of obesity, current tobacco use, other substance use, and major psychiatric disorders, were more likely to receive revascularization, and had lower 1-year mortality than older age groups. Revascularization was associated with at least a 3 times lower odds ratio of 1-year mortality in all age groups. In conclusion, young adults with STEMI had a unique set of risk factors and co-morbidities and were more likely to undergo revascularization than older age groups. In all age groups, female gender was associated with a higher burden of co-morbidities, decreased use of revascularization, and increased 1-year mortality.

Hypertension Management in Peripheral Artery Disease: A Mini Review

Lower extremity peripheral artery disease (PAD) affects over 230 million adults globally, with hypertension being one of the major risk factors for the development of PAD. Despite the high prevalence, patients with hypertension who have concomitant PAD are less likely to receive adequate therapy. Through this review, we present the current evidence underlying hypertension management in PAD, guideline-directed therapies, and areas pending further investigation. Multiple studies have shown that both high and relatively lower blood pressure levels are associated with worse health outcomes, including increased morbidity and mortality. Hence, guideline-directed recommendation involves cautious management of hypertensive patients with PAD while ensuring hypotension does not occur. Although any antihypertensive medication can be used to treat these patients, the 2017 American Heart Association/American College of Cardiology (AHA/ACC), 2017 European Society of Cardiology (ESC), and 2022 Canadian guidelines favor the use of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) as the initial choice. Importantly, data on blood pressure targets and treatment of hypertension in PAD are limited and largely stem from sub-group studies and post-hoc analysis. Large randomized trials in patients with PAD are required in the future to delineate hypertension management in this complex patient population.

Association of severity of coronary artery disease by SYNTAX score (SS) and lower extremity arterial disease by duplex ultrasound (DUS) study-an Indian perspective

Background

Coronary artery disease (CAD) and lower extremity artery disease (LEAD) often coexist. Ankle brachial index (ABI) has been shown to be an independent predictor of CAD. Studies have reported correlation of CAD and LEAD on the basis of ABI and also invasive angiography. But rigorous searching did not reveal any similar research where severity of LEAD was assessed by duplex ultrasound (DUS).

In this study, we assessed the association of severity and localisation of LEAD by DUS with SYNTAX score (SS).

Results

A total of 637 subjects above 45 years of age with coronary angiographic confirmation of CAD were studied in this single centre cross-sectional, descriptive and analytical research. High SS was significantly more common in subjects with LEAD (p = 0.04). In the femoro-popliteal segment, total occlusion of arteries was found in significantly more proportion of subjects with high SS. A progressive increase in mean SS was noted across the grades of arterial disease in the femoro-popliteal segment (p = 0.007). 85.2% of the LEAD was in the femoro-popliteal segment, while below-knee arterial disease was present in 98.5% of subjects with LEAD. Hypertension, smoking, history of CVE and presentation with ACS independently increased the risk of LEAD.

Conclusion

High prevalence of asymptomatic LEAD and association of high SS with LEAD as a whole as well as femoro-popliteal involvement suggests the need for a point of care DUS study (POCUS) since treatment varies with location and extent of disease which cannot be fathomed by ABI alone. Being the largest study on association of CAD and LEAD from Indian subcontinent till date and also the first study to use non-invasive tool as DUS for LEAD assessment while studying its association with CAD makes this a landmark experience.

The association between anxiety disorders and in-hospital outcomes in patients with myocardial infarction

BACKGROUND

Anxiety disorders are prevalent in patients with myocardial infarction (MI), but the effects of anxiety disorders on in-hospital outcomes within MI patients have not been well studied.

HYPOTHESIS

To examine the effects of concurrent anxiety disorders on in-hospital outcomes in MI patients.

METHODS

We conducted a retrospective cohort study in patients with a principal diagnosis of MI with and without anxiety disorders in the National Inpatient Sample 2016. A total of 129 305 primary hospitalizations for acute MI, 35 237 with ST-segment elevation myocardial infarction (STEMI), and 94 068 with non-ST elevation myocardial infarction (NSTEMI) were identified. Of these, 13 112 (10.1%) had anxiety (7.9% in STEMI and 11.0% in NSTEMI). We compared outcomes of anxiety and nonanxiety groups after propensity score matching for the patient and hospital demographics and relevant comorbidities.

RESULTS

After propensity score matching, the anxiety group had a lower incidence of in-hospital mortality (3.0% vs 4.4%, P < .001), cardiac arrest (2.1% vs 2.8%, P < .001), cardiogenic shock (4.9% vs 5.6%, P = .007), and ventricular arrhythmia (6.7% vs 7.9%, P < .001) than the nonanxiety group. In the NSTEMI subgroup, the anxiety group had significantly lower rates of in-hospital mortality (2.3% vs 3.5%, P < .001), cardiac arrest (1.1% vs 1.5%, P = .008), and cardiogenic shock (2.8% vs 3.5%, P = .008). In the STEMI subgroup, we found no differences in in-hospital outcomes (all P > .05) between the matched groups.

CONCLUSION

Although we found that anxiety was associated with better in-hospital outcomes, subgroup analysis revealed that this only applied to patients admitted for NSTEMI instead of STEMI.

Balance between angiogenic and anti-angiogenic isoforms of VEGF-A is associated with the complexity and severity of coronary artery disease

INTRODUCTION

Assessing the complexity of coronary artery disease (CAD) is clinically important. Vascular endothelial growth factor A (VEGF-A) is a powerful and the most important regulator of angiogenesis. It has been reported that the anti-angiogenic isoform of VEGF-A (VEGF-A₁₆₅b) inhibits angiogenesis. The purpose of this study was to evaluate the relationship between the complexities of CAD using the Syntax score (SS) and the levels of circulating total VEGF-A or VEGF-A₁₆₅b.

METHODS

A total of 268 patients who underwent percutaneous coronary intervention (PCI) were enrolled. Of these, 73 patients without acute coronary syndrome or previous revascularization were included in this study. These subjects were divided into two groups according to the SS. Circulating total VEGF-A and VEGF-A₁₆₅b levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

Circulating levels of total VEGF-A were significantly higher in the SS>22 (high SS) group than in the SS≤22 (low SS) group (p=0.018). Moreover, the ratio of VEGF-A₁₆₅b to total VEGF-A was significantly lower for the high SS group (p=0.004). The levels of total VEGF-A independently predicted high SS after adjusting for other significant variables among patients who underwent PCI (odds ratio, 1.004; 95% CI, 1.001 to 1.006; p=0.01).

CONCLUSIONS

These data indicated that high SS was associated with circulating levels of total VEGF-A and the ratio of VEGF-A₁₆₅b to total VEGF-A in patients with complex CAD.

Impact of betablockers on general and local outcome in patients hospitalized for lower extremity peripheral artery disease: The COPART Registry

Lower extremity peripheral artery disease (PAD) is one manifestation of atherosclerosis. Patients with PAD have an increased rate of mortality due to concurrent coronary artery disease and hypertension. Betablockers (BB) may, therefore, be prescribed, especially in case of heart failure. However, BB safety in PAD is controversial, because of presumed peripheral hemodynamic consequences of BB that could lead to worsening of symptoms in patients with PAD. In this context, we aimed to determine the impact of BB on all-cause and cardiovascular mortality and amputation rate at 1 year after hospitalization for PAD from the COPART Registry population. This is a prospective multicenter observational study collecting data from consecutive patients hospitalized for PAD in vascular medicine departments of 4 academic hospitals in France. Patients with, either claudication, critical limb ischemia or acute lower limb ischemia related to a documented PAD were included. We compared the outcomes of patients with BB versus those without BB in their prescription list at hospital discharge. The mean age of the study population was 70.9 years, predominantly composed of males (71%). Among the 1267 patients at admission, 28% were treated by BB for hypertension, prior myocardial infarction or heart failure. During their hospital stay, 40% underwent revascularization (including bypass surgery 29% and angioplasty 74%), 17% required an amputation, and 5% died. In a multivariate analysis, only prior myocardial infarction was found associated with BB prescription with an odds ratio (OR) of 3.11, P < 0.001. Conversely, chronic obstructive pulmonary disease or PAD with ulcer impeded BB prescription (OR: 0.57 and 0.64, P = 0.007; P = 0.001, respectively). One-year overall mortality of patients with BB did not differ from those without (23% vs. 23%, P = 0.95). The 1-year amputation rate did not differ either (4% vs. 6%, P = 0.14). Patients hospitalized for PAD with a BB in their prescription did not worsen their outcome at 1 year compared to patients without BB. Based on these safety data, prospective study could be conducted to assess the effect of BB on long-term mortality and amputation rate in patients with mild, moderate, and severe PAD.

Time-dependent effect of preinfarction angina pectoris and intermittent claudication on mortality following myocardial infarction: A Danish nationwide cohort study

BACKGROUND

As proxies for local and remote ischemic preconditioning, we examined whether preinfarction angina pectoris and intermittent claudication influenced mortality following myocardial infarction.

METHODS

Using medical registries, we conducted a nationwide population-based cohort study of all first-time myocardial infarction patients in Denmark during 2004-2012 (n=70,458). We computed all-cause and coronary mortality rate ratios (MRRs). We categorized time between angina/claudication presentation and subsequent myocardial infarction as 0-14, 15-30, 31-90, and > 90 days. We adjusted for age, sex, coronary intervention, comorbidities, and medication use.

RESULTS

Among all myocardial infarction patients, 18.4% had prior angina and 3.8% had prior intermittent claudication. Compared to patients without prior angina, the adjusted 30-day coronary MRR was 0.85 (95% confidence interval (CI): 0.80-0.92) for stable and 0.68 (95% CI: 0.58-0.79) for unstable angina patients. The mortality reduction increased when angina presented close to myocardial infarction and was higher for unstable than for stable angina. Thus, the 30-day coronary MRR was 0.72 (95% CI: 0.51-1.02) for stable angina and 0.35 (95% CI: 0.17-0.73) for unstable angina presenting within 14 days before MI. The results were robust for all-cause mortality and in numerous subgroups, including women, diabetics, patients treated with PCI, and patients treated with and without cardioprotective drugs. Preinfarction intermittent claudication was associated with higher short- and long-term mortality compared to patients without intermittent claudication.

CONCLUSIONS

Preinfarction angina reduced 30-day mortality, particularly when unstable angina closely preceded MI. Preinfarction intermittent claudication was associated with increased short- and long-term mortality.

Extrarenal atherosclerotic disease blunts renal recovery in patients with renovascular hypertension

BACKGROUND

Atherosclerotic renovascular disease (ARVD) is associated with high rates of coronary events and predicts mortality among patients with coronary artery disease (CAD). However, the impact of coronary atherosclerosis on renal outcomes after revascularization of ARVD is unclear. We hypothesized that CAD negatively impacts renal functional outcomes among patients with ARVD undergoing renal artery revascularization.

METHODS

Patients with ARVD who underwent echocardiography at Mayo Clinic, Rochester, Minnesota, USA between 2004 and 2012 were identified retrospectively and included if they had ejection fraction more than 50%. Renal and overall outcomes were compared among atherosclerotic renovascular disease patients with coronary artery disease (ARVD-C, n = 75) and without coronary artery disease (ARVD, n = 56), within 1 year from initial revascularization and included blood pressure control, renal function, and incident cardiovascular/cerebrovascular events.

RESULTS

Degree of renal artery stenosis was similar in both groups. ARVD-C had higher prevalence of diabetes, peripheral artery disease (PAD), and cerebrovascular disease, and lower baseline renal function. Risk of developing end-stage renal disease was higher in ARVD-C (11 vs. 2%, P = 0.05). Despite better control of blood pressure and cholesterol levels, renal function postrevascularization worsened in 15% of ARVD-C compared with 2% of ARVD (P = 0.01). Differences in clinical outcomes remained statistically significant after adjustment for covariables, including sex, baseline blood pressure, renal function, underlying diabetes, cholesterol levels, and medications. Similar differences in clinical outcomes were also associated with PAD and cerebrovascular disease.

CONCLUSION

CAD in patients with ARVD is a predictor of worse outcomes after renal revascularization, likely reflecting diffuse atherosclerotic disease. Further studies are needed to develop strategies to manage patients with vascular comorbidities and improve their outcomes.

Comparative Efficacy and Safety of Different Antiplatelet Agents for Prevention of Major Cardiovascular Events and Leg Amputations in Patients with Peripheral Arterial Disease: A Systematic Review and Network Meta-Analysis

There is a lack of consensus regarding which type of antiplatelet agent should be used in patients with peripheral arterial disease (PAD) and little is known on the advantages and disadvantages of dual antiplatelet therapy. We conducted a systematic review and network meta-analysis of available randomized controlled trials (RCT) comparing different antiplatelet drugs (Aspirin, Ticlopidine, Clopidogrel, Ticagrelor, Cilostazol, Picotamide and Vorapaxar as monotherapies or in combination with aspirin) in PAD patients (PROSPERO public database; CRD42014010299).We collated evidence from previous relevant meta-analyses and searched online databases. Primary efficacy endpoints were: (1) the composite rate of major adverse cardiovascular events (MACE; including vascular deaths, non-fatal myocardial infarction and non-fatal stroke), and (2) the rate of major leg amputations. The primary safety endpoint was the rate of severe bleeding events. Bayesian models were employed for multiple treatment comparisons and risk-stratified hierarchies of comparative efficacy were produced to aid medical decision making. Number-Needed-to-Treat (NNT) and Number-Needed-to-Harm (NNH) are reported in case of significant results. We analyzed 49 RCTs comprising 34,518 patients with 88,358 person-years of follow-up with placebo as reference treatment. Aspirin, Cilostazol, Vorapaxar and Picotamide were ineffective in reducing MACE. A significant MACE reduction was noted with Ticagrelor plus aspirin (RR: 0.67; 95%CrI: 0.46-0.96, NNT = 66), Clopidogrel (RR: 0.72; 95%CrI: 0.58-0.91, NNT = 80), Ticlopidine (RR: 0.75; 95%CrI: 0.58-0.96, NNT = 87), and Clopidogrel plus aspirin (RR: 0.78; 95%CrI: 0.61-0.99, NNT = 98). Dual antiplatelet therapy with Clopidogrel plus aspirin significantly reduced major amputations following leg revascularization (RR: 0.68; 95%CrI: 0.46-0.99 compared to aspirin, NNT = 94). The risk of severe bleeding was significantly higher with Ticlopidine (RR: 5.03; 95%CrI: 1.23-39.6, NNH = 25), Vorapaxar (RR: 1.80; 95%CrI: 1.22-2.69, NNH = 130), and Clopidogrel plus aspirin (RR: 1.48; 95%CrI: 1.05-2.10, NNH = 215). Clopidogrel monotherapy showed the most favourable benefit-harm profile (79% cumulative rank probability best and 77% cumulative rank probability safest). In conclusion, Clopidogrel should be the indicated antiplatelet agent in PAD patients. Dual antiplatelet therapy with aspirin and Clopidogrel can reduce the rate of major leg amputations following revascularization, but carries a slightly higher risk of severe bleeding.

Differential cellular effects of old and new oral anticoagulants: consequences to the genesis and progression of atherosclerosis

The main purpose of anticoagulants is to diminish fibrin formation, thereby decreasing the risk of venous or arterial thrombosis. Vitamin K antagonist have been used for many decades in order to achieve reduced thrombotic risk, despite major drawbacks of this class of drugs such as cumbersome dossing and monitoring of anticoagulant status. To overcome these drawbacks of VKA, new classes of anticoagulants have been developed including oral anticoagulants for direct inhibition of either thrombin or factor Xa, which can be administrated in a fixed dose without monitoring. Coagulation factors can activate cellular protease-activated receptors, thereby inducing cellular processes as inflammation, apoptosis, migration, and fibrosis. Therefore, inhibition of coagulation proteases not only attenuates fibrin formation, but may also influence pathophysiological processes like vascular calcification and atherosclerosis. Animal models revealed that VKA therapy induced both intima and media calcification and accelerated plaque vulnerability, whereas specific and direct inhibition of thrombin or factor Xa attenuated atherosclerosis. In this review we provide an overview of old and new oral anticoagulants, as well discuss potential pleiotropic effects with regard to calcification and atherosclerosis. Although translation from animal model to clinical patients seems difficult at first sight, effort should be made to fully understand the clinical implications of long-term oral anticoagulant therapy on vascular side effects.

An integrative review: application of self-efficacy instruments for walking in populations with peripheral arterial disease

OBJECTIVE

The study objective was to identify which self-efficacy measurement instruments are being used for walking in patients with peripheral arterial disease (PAD), the psychometrics of these instruments, and recommendations for use in research on patients with PAD.

BACKGROUND

PAD is a common problem for individuals with similar risk factors as cardiovascular disease (CVD). Experts recommend a supervised walking program with incremental increases in speed and distance as an initial treatment for patients with intermittent claudication. Because patients may experience pain while walking, there is a tendency to be nonadherent with exercise therapy, and many limit or avoid walking all together, resulting in a sedentary lifestyle. Self-efficacy plays a role in determining a person's confidence in his or her ability to participate in an exercise program. Data sources for this study were PubMed, Cumulative Index of Nursing and Allied Health Literature, PsycINFO, and the Cochrane database.

METHODS

The integrative review method described by Wittemore and Knafl was used for this review (Wittemore R, Knafl K. The integrative review: updated methodology. J Adv Nurs 2005;52:546-53.). Publications were retrieved electronically and reviewed for inclusion on the basis of studies that measured self-efficacy for walking in populations with PAD, peripheral vascular disease, and CVD. The analysis consisted of 9 publications.

RESULTS

Only 2 studies were specific to the population with PAD. The remaining studies addressed self-efficacy issues in CVD or congestive heart failure. The analysis identified 4 instruments based on Bandura's Social Cognitive Theory that were used to assess self-efficacy: (1) the Self-Efficacy Expectation Scale, (2) the Self-Efficacy for Managing Chronic Disease Scale, (3) the Performance-Based Efficacy Scale, and (4) the Barriers Self-Efficacy Scale. The Self-Efficacy Expectation Scale was most frequently used in these studies.

CONCLUSIONS

The use of the Self-Efficacy Expectation Scale instruments for walking in patients with PAD is limited because reliability and validity have been demonstrated in an older, mostly white population with CVD and congestive heart failure. Instruments that encompass the key constructs of self-efficacy, including physical, personal, and environmental aspects, would allow full evaluation with identification of potential explanations for success or failure for the chosen outcome. This should be taken into consideration in future studies when using instruments of self-efficacy.

High on-treatment platelet reactivity in peripheral endovascular procedures

The use of aspirin is considered the "gold standard" for the decrease of major adverse cardiovascular events in patients with atherosclerosis, including peripheral arterial disease (PAD), whereas a dual-antiplatelet regimen with aspirin and clopidogrel is usually indicated for such patients after angioplasty and stent deployment. However, a substantial number of subsequent adverse events still occur, even in patients who receive double-antiplatelet therapy. The "high on-treatment platelet reactivity" (HTPR) phenomenon has been lately recognized and plays a major role in the management of patients with PAD. Greater and more rapid inhibition of platelet aggregation has become the goal for new antiplatelet agents with the expectation of further improving outcomes for percutaneous intervention for PAD. The purpose of this review article is to highlight current evidence regarding the prevalence, aetiology, and clinical implications of HTPR in PAD as well as to discuss the possibilities of novel alternative antiplatelet regiments.

The impact of polyvascular disease on long-term outcome in percutaneous coronary intervention patients

BACKGROUND

Previous studies demonstrated the prognostic importance of concomitant polyvascular disease in patients with coronary artery disease (CAD). However, the significance of the number of diseased vascular territories and subclinical disease is unknown.

MATERIALS AND METHODS

The number of diseased vascular territories was evaluated in 2299 percutaneous coronary intervention (PCI) patients. Vascular disease was defined by documented atherosclerotic disease, either diagnosed in the medical history (clinical) or at the standardized cardiovascular screening (subclinical). The following territories were evaluated: cerebrovascular disease, peripheral arterial disease, abdominal aortic aneurysm and vascular renal disease. The outcome measures were all-cause mortality, cardiovascular mortality and a composite cardiovascular endpoint (myocardial infarction, stroke, cardiovascular mortality). Patients with monovascular disease (CAD) served as the reference category. Hazard ratios (HRs) were adjusted for baseline characteristics.

RESULTS

Mean follow-up was 7.3 years. The HRs (95% confidence interval) for patients with two diseased territories compared to monovascular disease were for all-cause mortality 1.60 (1.14-2.25), cardiovascular mortality 2.13 (1.29-3.50) and the combined cardiovascular endpoint 1.66 (1.20-2.31). Moreover, the HRs (95% confidence intervals) for patients with more than two diseased territories compared to monovascular disease were for all-cause mortality 3.81 (2.45-5.92), cardiovascular mortality 4.40 (2.32-8.35) and the combined cardiovascular endpoint 2.75 (1.69-4.47). The HRs of patients with subclinical disease were comparable to the HRs of patients with clinical disease.

CONCLUSIONS

In patients undergoing PCI, the presence of subclinical and clinical polyvascular disease is associated with an increased long-term mortality and morbidity. Moreover, the outcome is highly influenced by the number of diseased territories.

Relation between the ankle-brachial index and the complexity of coronary artery disease in older patients

Background

In the elderly, the ankle-brachial index (ABI) has greater than 90% sensitivity and specificity for peripheral artery disease identification. A well-known relation exists between peripheral artery disease and the number of diseased coronary vessels. Yet, other anatomical characteristics have important impacts on the type of treatment and prognosis.

Purpose

To determine the relation between ABI and the complexity of coronary artery disease, by different anatomical classifications.

Methods

This study was a prospective analysis of patients ≥65 years old who were undergoing elective coronary angiography for ischemic coronary disease. The ABI was calculated for each leg, as the ratio between the lowest ankle pressure and the highest brachial pressure. The analysis of coronary anatomy was performed by three interventional cardiologists; it included classification of each lesion with >50% diameter stenosis, according to the American Heart Association criteria, and calculation of the SYNTAX score.

Results

The study recruited 204 consecutive patients (median age: 72.5 years). Stable angina was present in 51% of patients. Although only 1% of patients reported peripheral artery disease, 45% exhibited an abnormal ABI. The number of lesions per patient, the number of patients with complex lesions, and the median SYNTAX scores were greater in the group with abnormal ABI. However, among 144 patients with obstructive coronary artery disease, despite abnormal ABI being able to identify a higher rate of patients with B2 or C type lesions (70.9% versus 53.8%; P=0.039), the mean SYNTAX scores (13 versus 9; P=0.14), and the proportion of patients with SYNTAX score >16 (34.2% versus 27.7%; P=0.47), were similar, irrespective of ABI.

Conclusion

In patients ≥65 years old the presence of peripheral artery disease could discriminate a group of patients with greater occurrence of B2 and C type lesions, but similar median SYNTAX score.

Prognostic usefulness of clinical and subclinical peripheral arterial disease in men with stable coronary heart disease

The prognostic value of symptomatic peripheral arterial disease (PAD) in patients with coronary heart disease (CHD) is well documented, but few reports differentiating between symptomatic and asymptomatic forms of PAD are available. We investigated the respective prognostic effect of clinical and subclinical PAD on long-term all-cause mortality in patients with stable CHD. We analyzed 710 patients with stable CHD referred for hospitalization for CHD evaluation and management. As a part of the study, they completed questionnaires on medical history, underwent a standardized clinical examination, including ankle-brachial index (ABI) measurement, and provided a fasting blood sample. Three groups of patients were individualized: no PAD (no history of PAD and ABI >0.9 but ≤1.4); subclinical PAD (no history of PAD but abnormal ABI [i.e., ≤0.9 or >1.4); and clinical PAD (history of claudication, peripheral arterial surgery, or amputation due to PAD). Clinical and subclinical PAD was present in 83 (11.7%) and 181 (25.5%) patients, respectively. After a median follow-up of 7.2 years, 130 patients died. On multivariate analysis adjusted for age, hypertension, diabetes, dyslipidemia, smoking, left ventricular ejection fraction, CHD duration, heart rate, history of stroke or transient ischemic attack, and coronary revascularization, previous clinical PAD (hazard ratio 2.11, 95% confidence interval 1.28 to 3.47) and subclinical PAD (hazard ratio 1.65, 95% confidence interval 1.11 to 2.44) were significantly associated with increased all-cause mortality. In conclusion, our study has demonstrated that the detection of subclinical PAD by ABI in patients with stable CHD provides additional information for long-term mortality risk evaluation.

The impact of blood coagulability on atherosclerosis and cardiovascular disease

Although the link between blood coagulation and atherogenesis has been long postulated, only recently, and through the extensive work on transgenic mice, crossbred on an atherogenic background, has the direction of this interaction become visible. In general, hypercoagulability in mice tends to increase atherosclerosis, whereas hypocoagulability reduces the atherosclerotic burden, depending on the mouse model used. The information on a direct relationship between coagulation and atherosclerosis in humans, however, is not that clear. Almost all coagulation proteins, including tissue factor, are found in atherosclerotic lesions in humans. In addition to producing local fibrin, a matrix for cell growth, serine proteases such as thrombin may be very important in cell signaling processes, acting through the activation of protease-activated receptors (PARs). Activation of PARs on vascular cells drives many complex processes involved in the development and progression of atherosclerosis, including inflammation, angiogenesis, and cell proliferation. Although current imaging techniques do not allow for a detailed analysis of atherosclerotic lesion phenotype, hypercoagulability, defined either by gene defects of coagulation proteins or elevated levels of circulating markers of activated coagulation, has been linked to atherosclerosis-related ischemic arterial disease. New, high-resolution imaging techniques and sensitive markers of activated coagulation are needed in order to study a causal contribution of hypercoagulability to the pathophysiology of atherosclerosis. Novel selective inhibitors of coagulation enzymes potentially have vascular effects, including inhibition of atherogenesis through attenuation of inflammatory pathways. Therefore, we propose that studying the long-term vascular side effects of this novel class of oral anticoagulants should become a clinical research priority.

β-Blockers in Patients With Intermittent Claudication and Arterial Hypertension

The use of β-receptor blockers in peripheral arterial disease is controversial for their impact on vasomotor tone. The β-blocker nebivolol possesses vasodilating, endothelium-dependent, NO-releasing properties that might be beneficial in peripheral arterial disease. The aim of the study was to evaluate the effects and tolerability of nebivolol in comparison with metoprolol in these patients. A total of 128 patients with intermittent claudication and essential hypertension were included and double-blind randomized to receive 5 mg of nebivolol (N=65) or 95 mg of metoprolol (N=63) once daily. End points were changes in ankle-brachial index, initial and absolute claudication distance, endothelial function assessed by flow-mediated dilatation of the brachial artery, blood pressure, and quality of life using the claudication scale questionnaire. End point analysis was possible in 109 patients (85.2%). After the 48-week treatment period, ankle-brachial index and absolute claudication distance improved significantly in both patient groups ( P <0.05 for both), with no difference across treatments. A significant increase of initial claudication distance was found in the nebivolol group. Adjusted mean change of initial claudication distance was 33.9% after nebivolol ( P =0.003) and 16.6% after metoprolol ( P =0.12) treatment. Quality of life was not influenced by either treatment, and there was no relevant change in flow-mediated dilatation in patients treated with nebivolol or metoprolol ( P =0.16). Both drugs were equally effective in lowering blood pressure. In conclusion, β-blocker therapy was well tolerated in patients with intermittent claudication and arterial hypertension during a treatment period of ≈1 year. In the direct comparison, there was no significant difference between nebivolol and metoprolol.

Effect of peripheral arterial disease on in-hospital outcomes after primary percutaneous coronary intervention for acute myocardial infarction

The presence of peripheral arterial disease (PAD) in patients with stable coronary artery disease is associated with an increased long-term risk of death, myocardial infarction, and stroke. However, the effect of PAD on short-term outcomes in patients with acute myocardial infarction is less well understood. A total of 9,015 consecutive patients with acute myocardial infarction from the New York State Coronary Angioplasty Reporting System database, all of whom had undergone primary percutaneous coronary intervention in 1998 and 1999, were analyzed. The diagnosis of PAD was determined by a history of aortoiliac, femoral-popliteal, or carotid disease. A logistic regression model was used to determine the relation between PAD and in-hospital death and major adverse cardiovascular events, which included a composite of death, recurrent myocardial infarction, stroke, acute vessel occlusion, stent thrombosis, emergency coronary artery bypass surgery, and vascular injury. PAD had been diagnosed in 529 (5.9%) of the 9,015 patients. Patients with PAD had greater rates of diabetes mellitus, hypertension, and chronic kidney disease and were significantly more likely to develop heart failure, cardiogenic shock, and hemodynamic instability. The incidence of major adverse cardiovascular events was significantly greater in patients with PAD than in patients without PAD (20.4% vs 7.0%, p <0.001). Similarly, the in-hospital mortality rate was significantly greater among the patients with PAD (13% vs 3.8%, p <0.001). After adjusting for the baseline and procedural characteristics, PAD remained an independent predictor of in-hospital mortality (odds ratio 2.2, 95% confidence interval 1.7 to 3.0, p <0.001). In conclusion, PAD was independently associated with a doubling of the in-hospital mortality risk among patients undergoing primary percutaneous coronary intervention for acute myocardial infarction.

Prognostic value of hypotensive blood pressure response during single-stage exercise test on long-term outcome in patients with known or suspected peripheral arterial disease

OBJECTIVE

A decline in systolic blood pressure during exercise is thought to be a sign of severe coronary artery disease. However, no studies have yet examined this effect in patients with known or suspected peripheral arterial disease. Therefore, we investigated the prognostic value of hypotensive blood pressure response after single-stage exercise test on long-term mortality, major adverse cerebrovascular and cardiac events (MACCE) and the effects of statin, beta-blocker and aspirin use in patients with known or suspected peripheral arterial disease.

METHODS

A total of 2022 patients were enrolled in an observational study with a mean follow-up of 5 years. Hypotensive blood pressure response, 4.6% of the total population, was defined as a drop in exercise systolic blood pressure below resting systolic blood pressure.

RESULTS

Our study showed that hypotensive blood pressure response was associated with an increased risk of all-cause mortality [hazard ratio (HR): 1.74, 95% confidence interval (CI): 1.10-2.73] and MACCE (HR: 1.85, 95% CI: 1.14-3.00), independent of other clinical variables. Additionally, after adjustments for clinical risk factors and propensity score, baseline statin use was associated with a reduced risk of all-cause mortality (HR: 0.60, 95% CI: 0.44-0.80). Besides, statin and aspirin use were both also associated with a reduced risk of MACCE (HR: 0.65, 95% CI: 0.47-0.89 and HR: 0.69, 95% CI: 0.53-0.88, respectively).

CONCLUSION

Hypotensive blood pressure response after single-stage treadmill exercise tests in patients with known or suspected peripheral arterial disease was associated with a higher risk for all-cause long-term mortality and MACCE, which might be reduced by statin and aspirin use.

Usefulness of hypertensive blood pressure response during a single-stage exercise test to predict long-term outcome in patients with peripheral arterial disease

The prognostic value of a hypertensive blood pressure (BP) response is still unclear. Therefore, the prognostic value of a hypertensive BP response in patients during single-stage exercise testing for peripheral arterial disease (PAD) on long-term mortality and major adverse cerebrovascular and cardiac events (MACCEs) was investigated. In addition, effects of statin, beta-blocker, and aspirin use in patients with known or suspected PAD were studied. A total of 2,109 patients were enrolled in an observational prospective study from 1993 to 2005. Hypertensive BP response was defined as an increase in systolic BP > or = 55 mm Hg (95(th) percentile within our population) after a single-stage treadmill exercise test. The outcome was obtained by using the civil registries, and a questionnaire about cardiac events was sent to all survivals. Hypertensive BP response was associated with increased risk of long-term mortality (hazard ratio [HR] 1.42, 95% confidence interval [CI] 1.12 to 1.80) and MACCEs (HR 1.47, 95% CI 1.09 to 1.97). After adjustments for clinical risk factors and propensity score, baseline statin use was associated with reduced risk of long-term mortality (HR 0.59, 95% CI 0.44 to 0.79), and statin, beta-blocker, and aspirin use were associated with reduced risk of MACCEs (HR 0.59, 95% CI 0.43 to 0.81; HR 0.75, 95% CI 0.60 to 0.95; HR 0.73, 95% CI, 0.57 to 0.92, respectively). In conclusion, hypertensive BP response at exercise in patients with known or suspected PAD is an important independent risk factor for all-cause long-term mortality and MACCEs, whereas statin, beta-blocker, and aspirin use were associated with an improved outcome.

Management of peripheral arterial disease patients: comparing the ACC/AHA and TASC-II guidelines

BACKGROUND

Peripheral arterial disease (PAD) is a common manifestation of systemic atherosclerosis associated with a high risk of morbidity and mortality from cardiovascular events. Despite this, PAD is often undiagnosed and, therefore, undertreated.

OBJECTIVE

The purpose of this review is to highlight and provide clinical insight into the similarities and differences between the available PAD treatment guidelines developed by the American College of Cardiology/American Heart Association (ACC/AHA) and the Trans-Atlantic Inter-Society Consensus II (TASC II) working group.

METHODS

Recommendations from the ACC/AHA 2005 Practice Guidelines for the Management of Patients with Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic) and TASC II Inter-Society Consensus for the Management of Peripheral Arterial users for personal Disease, initiated in 2004 and published in 2007, were compared. Supplemental information was obtained by searching the PubMed and MEDLINE databases using relevant terms. Unintentional bias may have been introduced into the manuscript by not performing a systematic review of the literature with pre-defined search terms.

FINDINGS AND CONCLUSIONS

While some variation exists in the content of the recommendations, both documents agree on the need for aggressive management of patients with PAD. In spite of these recommendations, there is a general lack of adherence to the current guidelines-a critical concern considering the high morbidity and mortality associated with the disease. However, the results of ongoing clinical trials may serve to increase awareness of the importance of aggressive management of PAD.

C-Reactive Protein Predicts Future Arterial and Cardiovascular Events in Patients With Symptomatic Peripheral Arterial Disease

High-sensitivity C-reactive protein is associated with increased risk of cardiovascular events. Consequently, the predictive value of this protein in patients with symptomatic peripheral arterial disease was examined. In all, 452 patients with symptomatic peripheral arterial disease had high-sensitivity C-reactive protein measured at baseline (mean follow-up = 2.1 ± 1.4 years). Events were defined as primary (death, amputation, or peripheral revascularization) or secondary (lower limb thrombosis, myocardial infarction, or stroke).The level of high-sensitivity C-reactive protein was significantly higher among those dying ( P = .04), those who needed amputation ( P = .01), and those developing an overall secondary endpoint ( P = .02). By receiver-operating characteristic curve analysis, the optimal cutoff point was constantly approximately 10 to 20 mg/L with a sensitivity and specificity of 56% to 63% and 54% to 56%, respectively. Baseline levels of high-sensitivity C-reactive protein are associated with future arterial events in symptomatic peripheral arterial disease patients but cannot stand alone as a predictive tool.

Effects of combined candesartan and ACE inhibitors on BNP, markers of inflammation and oxidative stress, and glucose regulation in patients with symptomatic heart failure

BACKGROUND

We assessed the effects of candesartan in addition to angiotensin-converting enzyme (ACE) inhibitors on N-terminal pro-type natriuretic peptide (Nt-proBNP), systemic markers of inflammation and oxidative stress as well as on glucose regulation in patients with heart failure (HF).

METHODS AND RESULTS

Eighty patients with HF ages 62.5 +/- 8.4 years presenting mostly with New York Heart Association class II symptoms (class II = 57.5%, III = 41.3%), and mean left ventricular ejection fraction 27.1 +/- 7.3% were recruited. The patients were randomized to receive candesartan titrated to 32 mg 1 per day versus placebo in double-blind fashion for 6 months. Nt-proBNP, markers of inflammation and oxidative stress, glucose, insulin, and fasting insulin resistance index were analyzed. Candesartan decreased Nt-proBNP (median value = 12.4% versus -20.4%; [candesartan] P = .05), and high-sensitivity C-reactive protein (hsCRP) (+5.32% versus -20.3% [candesartan]; P = 0.046), without significantly influencing serum interleukin-6, interleukin-18, adhesion molecules, or markers of oxidative stress. Blood glucose decreased in patients treated with candesartan with a significantly greater effect in patients with higher blood glucose levels (P < .01 for interaction).

CONCLUSIONS

The addition of candesartan to ACE inhibitor and beta-blocker decreases Nt-proBNP and hsCRP, but does not change the other markers of inflammation or oxidative stress in patients with heart failure. Dual angiotensin-II suppression also decreased blood glucose with a greater impact in patients with higher blood glucose level.

Mortality in peripheral arterial disease: a comparison of patients managed by vascular specialists and general practitioners

BACKGROUND

Peripheral arterial disease (PAD) is undertreated by general practitioners (GPs). However, the impact of the suboptimal clinical management is unknown.

OBJECTIVE

To assess the mortality rate of PAD patients in relation to the type of physician who provides their care (GP or vascular specialist).

DESIGN

Prospective study.

SETTING

Primary care practice and academic vascular laboratory.

PARTICIPANTS

GP patients (n = 60) were those of the Peripheral Arteriopathy and Cardiovascular Events study (PACE). Patients managed by specialists (n = 82) were consecutive subjects with established PAD who were referred to our vascular laboratory during the enrollment period of the PACE study.

MEASUREMENTS

All-cause and cardiovascular mortality.

RESULTS

After 32 months of follow-up, specialist management was associated with a lower rate of all-cause mortality (RR = 0.04; 95% CI 0.01-0.34; p = .003) and cardiovascular mortality (RR = 0.07; 95% CI 0.01-0.65; p = .020), after adjustment for patients' characteristics. Specialists were more likely to use antiplatelet agents (93% vs 73%, p < .001), statins (62% vs 25%, p < .001) and beta blockers (28% vs 3%, p < .001). Survival differences between specialists and GPs disappeared once the use of pharmacotherapies was added to the proportional hazard model. The fully adjusted model showed that the use of statins was significantly associated with a reduced risk of all-cause mortality (RR = 0.02; 95% CI 0.01-0.73, p = .034) and cardiovascular mortality (RR = 0.02; 95% CI 0.01-0.71, p = .033).

CONCLUSIONS

Specialist management of patients with symptomatic PAD resulted in better survival than generalist management. This effect appears to be mainly caused by the more frequent use of effective medicines by specialists.

Fibrin D-dimer fragments enhance inflammatory responses in macrophages: role in advancing atherosclerosis

1. Fibrin D-dimer is considered a consistent and independent marker of the risk of cardiovascular disease in population studies, as well as being related to atherosclerosis severity in patients. However, the role of fibrin D-dimer in macrophage-derived foam cell formation during atherogenesis remains unclear. 2. In the present study, using microarray techniques, we determined the effects of 100 ng/mL fibrin D-dimer fragments on macrophage cell function in atherosclerosis by investigating the expression levels of 128 genes related to the atherosclerotic pathophysiological processes. 3. The results showed that 27 genes were enhanced by D-dimer fragments to over twofold of control. These 27 genes belonged to six groups and included adhesion molecules, extracellular molecules, molecules related to lipid transport and metabolism, cell growth and proliferation molecules, transcription regulators and genes responsive to stress. We proceeded to determine the expression levels of five of these genes (intercellular adhesion molecule-1, matrix metalloproteinase-9, oxidized low-density lipoprotein receptor 1, vascular endothelial growth factor A and peroxisome proliferator-activated receptor alpha) using SYBR real-time polymerase chain reaction. The results confirmed gene upregulation, similar to the results obtained with the microarray, following treatment with D-dimer. 4. Therefore, the present study provides direct evidence regarding the pro-atherosclerotic role of D-dimer in macrophage function, which is mainly to enhance the inflammatory response during macrophage-derived foam cell formation.

Adipose tissue interleukin-18 mRNA and plasma interleukin-18: effect of obesity and exercise

OBJECTIVES

Obesity and a physically inactive lifestyle are associated with increased risk of developing insulin resistance. The hypothesis that obesity is associated with increased adipose tissue (AT) interleukin (IL)-18 mRNA expression and that AT IL-18 mRNA expression is related to insulin resistance was tested. Furthermore, we speculated that acute exercise and exercise training would regulate AT IL-18 mRNA expression.

RESEARCH METHODS AND PROCEDURES

Non-obese subjects with BMI < 30 kg/m(2) (women: n = 18; men; n = 11) and obese subjects with BMI >30 kg/m(2) (women: n = 6; men: n = 7) participated in the study. Blood samples and abdominal subcutaneous AT biopsies were obtained at rest, immediately after an acute exercise bout, and at 2 hours or 10 hours of recovery. After 8 weeks of exercise training of the obese group, sampling was repeated 48 hours after the last training session.

RESULTS

AT IL-18 mRNA content and plasma IL-18 concentration were higher (p < 0.05) in the obese group than in the non-obese group. AT IL-18 mRNA content and plasma IL-18 concentration was positively correlated (p < 0.05) with insulin resistance. While acute exercise did not affect IL-18 mRNA expression at the studied time-points, exercise training reduced AT IL-18 mRNA content by 20% in both sexes.

DISCUSSION

Because obesity and insulin resistance were associated with elevated AT IL-18 mRNA and plasma IL-18 levels, the training-induced lowering of AT IL-18 mRNA content may contribute to the beneficial effects of regular physical activity with improved insulin sensitivity.

Managing Risk Factors for Atherosclerosis in Critical Limb Ischaemia

OBJECTIVE

To review the best medical management of critical limb ischaemia (CLI).

METHODS

Published studies dealing with CLI and risk factors were searched for via PUBMED.

FINDINGS AND CONCLUSIONS

Patients with critical limb ischaemia (CLI) have a one and ten year mortality of approximately 20% and 75% respectively. Risk factors for the development of peripheral atherosclerosis are the same as for coronary and cerebrovascular atherosclerosis namely diabetes mellitus, hyperlipidaemia, arterial hypertension, and smoking. As there are few studies of risk factor for peripheral arterial occlusive disease (PAOD), treatment recommendations are often based on studies in patients with coronary or cerebrovascular atherosclerosis. While waiting for specific studies, CLI patients should be treated according to current guidelines for other atherosclerotic patients.

The Influence of Peripheral Arterial Disease on Outcomes

OBJECTIVES

We aimed to evaluate clinical outcomes among peripheral arterial disease (PAD) patients following percutaneous coronary intervention (PCI).

BACKGROUND

A significant proportion of patients with coronary artery disease undergoing PCI have concomitant PAD, which may be associated with worse outcomes.

METHODS

We performed a pooled analysis of 8 randomized PCI trials. We included multicenter PCI trials that compared antiplatelet therapies (EPIC, EPILOG, EPISTENT, RAPPORT, CAPTURE, IMPACT-II, TARGET, and CREDO) and had baseline PAD status recorded. Multivariable analyses were performed with stepwise logistic regression for 7- and 30-day outcomes and Cox regression for 6-month and 1-year events.

RESULTS

In our pooled analysis of 19,867 patients undergoing PCI, 1,602 (8.1%) were previously diagnosed with PAD. Patients with PAD had higher incidences of 7-day death (1.0% vs. 0.4%; p < 0.001) or myocardial infarction (MI) (6.8% vs. 5.6%; p = 0.047), 30-day death (1.7% vs. 0.7%; p < 0.001) or MI (7.4% vs. 6.1%; p = 0.05), 6-month death (4.2% vs. 1.5%; p < 0.001) or MI (9.1%, vs. 7.7%; p = 0.048), and 1-year death (5.0% vs. 2.1%; p < 0.001). There was a trend toward higher major bleeding risk with PAD (4.8% vs. 3.9%; p = 0.06). With multivariable analyses, PAD remains a significant predictor of mortality at 30 days (hazard ratio [HR] 1.67, 95% confidence interval [CI] 1.03 to 2.70; p = 0.039), 6 months (HR 1.76, 95% CI 1.31 to 2.37; p < 0.001), and 1 year (HR 1.46, 95% CI 1.08 to 1.96; p = 0.013).

CONCLUSIONS

The presence of PAD is associated with higher rates of post-PCI death and MI, and is an independent predictor of short- and long-term mortality.

Supporting a call to action for peripheral artery disease: Insights from two prospective clinical registries

BACKGROUND

Patients affected by peripheral arterial disease (PAD) incur a heightened risk of adverse cardiovascular events, including stroke, myocardial infarction, and vascular mortality. We examined risk factors, medications, and prognosis of outpatients with PAD enrolled in two national, prospective, practice-based Canadian registries that encompassed 484 physician practices: the Vascular Protection and Guideline Oriented Approach in Lipid Lowering registries.

METHODS

The 2 registries were combined to analyze 9810 patients with vascular disease, diabetes mellitus, or age 65 years or older plus at least 2 additional cardiovascular risk factors. Risk factors, medications, and major cardiovascular events were recorded at baseline and again at 6 months' follow-up.

RESULTS

Compared with patients without PAD (n = 8303), those with PAD (n = 1507) had substantially worse risk factor profiles and were more likely to have coexisting coronary or cerebrovascular disease. Both groups received high rates of treatment with evidence-based therapies, including antiplatelet drugs, statins, and angiotensin-converting enzyme inhibitors. Despite this, patients with PAD had a nearly twofold higher risk of major cardiovascular events at 6 months than non-PAD patients (7.3% vs 4.1%; P < .0001). After adjustment for multiple confounding factors, the presence of PAD at baseline continued to predict a heightened risk of adverse vascular sequelae (odds ratio, 1.54; 95% confidence interval, 1.18-2.01; P < .0001).

CONCLUSIONS

These data support a strong relationship between PAD and worsened vascular prognosis that is independent of both conventional vascular risk factors and concomitant cardiovascular disease. The presence of PAD should therefore provide a clear impetus for intensive risk factor modification and use of preventive medical therapy in affected patients.

Subclinical Inflammation and Prothrombotic State in Heart Transplant Recipients: Impact of Cyclosporin Microemulsion vs. Tacrolimus

BACKGROUND

Subclinical inflammation is related to adverse events in patients with coronary artery disease. In the present study, we determined the changes in hemostatic parameters and inflammatory markers in a large cohort of dyslipidemic cardiac transplant recipients compared with dyslipidemic healthy controls, and the effect of cyclosporin microemulsion (CsA) vs. tacrolimus immunoprophylaxis on these parameters.

METHODS

Stable cardiac transplant recipients (n=129) aged 56.7+/-10.1 years, 79+/-42 months postcardiac transplantation, and 26 mildly dyslipidemic healthy control subjects had serum measurements for lipids and lipoproteins, hemostatic parameters, and selected inflammatory markers. Transplant recipients were randomized to either continuation of CsA maintenance or conversion to tacrolimus immunoprophylaxis and were reassessed after six months.

RESULTS

CsA-maintained cardiac transplant recipients exhibited a significant elevation in Factor VIII, Von Willebrand factor, fibrinogen and PAI-I compared with healthy control subjects (all P<0.05). Similarly, cardiac transplant patients yielded a significantly elevated C-reactive protein (CRP) (4.11+/-6.25 [transplant group (TX)] vs. 2.09+/-2.21 mg/L [control group (CTL)]; P=0.0195), and homocysteine (19.2+/-8.8 [TX] vs. 9.70+/-2.45 microM [CTL]; P<0.001). VCAM, ICAM, E- and P-selectins were also significantly higher in transplant patients than in controls (all P<0.05). The conversion from CsA to tacrolimus resulted in a significant decrease in uric acid, total- and LDL-cholesterol, apolipoprotein B, creatinine, and homocysteine levels (all P<0.05).

CONCLUSIONS

Stable long-term CsA-maintained cardiac transplant patients exhibit a significant and general increase in hemostatic parameters and markers for subclinical inflammation. Tacrolimus conversion improved the patient lipid profile and decreased serum creatinine, uric acid, and homocysteine without any significant effect on the other markers.

Acute respiratory distress syndrome and pneumonia: a comprehensive review of clinical data

Acute respiratory distress syndrome (ARDS) and pneumonia are closely correlated in the critically ill patient. Whereas ARDS is often complicated by nosocomial pneumonia, pulmonary infection is also the most frequent single cause of ARDS. The prevalence of pneumonia during the course of ARDS seems to be particularly high, but whether persons with ARDS are more susceptible to pneumonia or simply have more risk factors remains unknown because of methodological limitations. Recent research suggests that host factors have a major bearing on the development of ARDS. To date, sepsis seems to be the principal link between pneumonia and ARDS. However, prospective observational data on this supposed sequence are not available. The individual role of specific pathogens for the development of ARDS is difficult to assess, because prospective studies are missing. Respiratory viruses have received particular attention, but this review suggests that infections with coronavirus and avian influenza virus (H5N1) are associated with a high incidence of ARDS.

Cardioprotective Medication Is Associated With Improved Survival in Patients With Peripheral Arterial Disease

OBJECTIVES

We sought to investigate the effect of cardiac medication on long-term mortality in patients with peripheral arterial disease (PAD).

BACKGROUND

Peripheral arterial disease is associated with increased cardiovascular morbidity and mortality. Treatment guidelines recommend aggressive management of risk factors and lifestyle modifications. However, the potential benefit of cardiac medication in patients with PAD remains ill defined.

METHODS

In this prospective observational cohort study, 2,420 consecutive patients (age, 64 +/- 11 years, 72% men) with PAD (ankle-brachial index < or =0.90) were screened for clinical risk factors and cardiac medication. Follow-up end point was death from any cause. Propensity scores for statins, beta-blockers, aspirin, angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers, diuretics, nitrates, coumarins, and digoxin were calculated. Cox regression models were used to analyze the relation between cardiac medication and long-term mortality.

RESULTS

Medical history included diabetes mellitus in 436 patients (18%), hypercholesterolemia in 581 (24%), smoking in 837 (35%), hypertension in 1,162 (48%), coronary artery disease in 1,065 (44%), and a history of heart failure in 214 (9%). Mean ankle-brachial index was 0.58 (+/-0.18). During a median follow-up of eight years, 1,067 patients (44%) died. After adjustment for risk factors and propensity scores, statins (hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.36 to 0.58), beta-blockers (HR 0.68, 95% CI 0.58 to 0.80), aspirins (HR 0.72, 95% CI 0.61 to 0.84), and ACE inhibitors (HR 0.80, 95% CI 0.69 to 0.94) were significantly associated with a reduced risk of long-term mortality.

CONCLUSIONS

On the basis of this observational longitudinal study, statins, beta-blockers, aspirins, and ACE inhibitors are associated with a reduction in long-term mortality in patients with PAD.

Hypercoagulability markers in young asymptomatic heterozygous carriers of factor V Leiden (G1691A) or prothrombin (G20210A) variant

BACKGROUND

Mutations in factor V (factor V Leiden-G1691A) and prothrombin (G20210A) genes are important risk factors for thrombophilia due to their high incidence in patients with thromboembolic events, especially among the young. However, it is not clear if levels of hypercoagulability markers are significantly altered in asymptomatic young carriers of factor V Leiden or prothrombin G20210A.

METHODS

Hemostatic status of 32 asymptomatic young individuals carrying these mutations and of 18 normal control individuals was investigated through the determination of plasma thrombomodulin (TM), prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT) and D-dimer.

RESULTS

No significant differences were observed in these hemostatic markers when comparing groups of individuals carrying mutations and the control group.

CONCLUSION

Analysis of these results leads to the conclusion that the presence of these mutations, in the absence of acquired risk factors, does not constantly predispose these young carriers to a state of hypercoagulability.

Antiatherogenic effects of dietary plant sterols are associated with inhibition of proinflammatory cytokine production in Apo E-KO mice

Dietary phytosterols significantly reduce atherosclerosis in apo E-deficient mice. Because atherosclerosis is a chronic inflammatory disease, we investigated whether the antiatherogenic effects of phytosterols are associated with reductions in proinflammatory cytokine production as well as the effect of this diet on global immunocompetence. Apolipoprotein (apo) E-deficient mice were fed a cholesterol-supplemented diet in the presence or absence of 2% dietary phytosterols for 14 wk and then immunized with ovalbumin. The relations between plasma lipid concentrations, atherosclerotic lesions, and cytokine production and proinflammatory stimuli or foreign antigens were characterized. Phytosterol-enriched diets were strongly associated with reduced plasma cholesterol concentrations and atherosclerosis in conjunction with higher anti-inflammatory [interleukin (IL)-10] and lower proinflammatory cytokine [IL-6, tumor necrosis factor (TNF)-alpha] production. In contrast, development of cytokine and chemokine responses to ovalbumin was as strong as or even improved in the phytosterol-treated mice relative to controls. The antiatherogenic effects of dietary phytosterols in apo E-knockout mice were associated with beneficial alterations in both lipoprotein metabolism and inflammatory pathways. Decreased capacity to mount proinflammatory cytokine and chemokine responses to inflammatory stimuli did not interfere with the global immunocompetence of such mice. Thus, the desirable suppression of proinflammatory cytokine production that was associated with inhibition of atherogenesis did not impair the capacity to mount responses to foreign antigens.

Blood coagulation and the risk of atherothrombosis: a complex relationship

The principles of Virchov's triad appear to be operational in atherothrombosis or arterial thrombosis: local flow changes and particularly vacular wall damage are the main pathophysiological elements. Furthermore, alterations in arterial blood composition are also involved although the specific role and importance of blood coagulation is an ongoing matter of debate. In this review we provide support for the hypothesis that activated blood coagulation is an essential determinant of the risk of atherothrombotic complications. We distinguish two phases in atherosclerosis: In the first phase, atherosclerosis develops under influence of "classical" risk factors, i.e. both genetic and acquired forces. While fibrinogen/fibrin molecules participate in early plaque lesions, increased activity of systemic coagulation is of no major influence on the risk of arterial thrombosis, except in rare cases where a number of specific procoagulant forces collide. Despite the presence of tissue factor – factor VII complex it is unlikely that all fibrin in the atherosclerotic plaque is the direct result from local clotting activity. The dominant effect of coagulation in this phase is anticoagulant, i.e. thrombin enhances protein C activation through its binding to endothelial thrombomodulin.

The second phase is characterized by advancing atherosclerosis, with greater impact of inflammation as indicated by an elevated level of plasma C-reactive protein, the result of increased production influenced by interleukin-6. Inflammation overwhelms protective anticoagulant forces, which in itself may have become less efficient due to down regulation of thrombomodulin and endothelial cell protein C receptor (EPCR) expression. In this phase, the inflammatory drive leads to recurrent induction of tissue factor and assembly of catalytic complexes on aggregated cells and on microparticles, maintaining a certain level of thrombin production and fibrin formation. In advanced atherosclerosis systemic and vascular wall driven coagulation becomes more important and elevated levels of D-dimer fragments should be interpreted as markers of this hypercoagulability.