Triglycerides and vascular risk: insights from epidemiological data and interventional studies

The role of elevated triglyceride (TG) levels in the pathogenesis of atherosclerosis is controversial. Some studies suggest that TG might play a direct role in the development of vascular disease. Elevated TG levels are also associated with other vascular risk factors and may therefore represent an indirect marker of a high risk state. Another issue is that laboratory measurements of TG levels frequently show a substantial variability. Accumulating epidemiological data show that there is an independent association of TG levels with vascular risk. Some interventional studies also suggested that lowering TG levels might prevent vascular events. It appears that TG might be more important as therapeutic targets against a background of optimal low density lipoprotein cholesterol (LDL-C) levels. In this context, statins that are more effective in reducing TG levels, fibrates that can safely be combined with statins or fixed fibrate and statin combinations, as well as new, better tolerated nicotinic acid formulations might prove to be particularly beneficial.

Lipid lowering agents and the endothelium: an update after 4 years

Endothelial dysfunction represents an important step in the pathogenesis of atherosclerosis. All vascular risk factors can induce endothelial dysfunction, which in turn results in the loss of the protective effects of the endothelium culminating in the development of atherosclerosis. Dyslipidemia is a major vascular risk factor and is associated with endothelial dysfunction. Several studies showed that lipid-lowering agents exert beneficial effects on endothelial function in different populations at increased vascular risk, including patients without dyslipidemia. Therefore, other actions besides lipid-profile modification appear to be implicated in this benefit. However, it is unclear whether the improvement in endothelial function independently contributes to the vascular risk reduction during lipid-lowering treatment (e.g. with statins). It is also unclear whether the assessment of endothelial function would help identify patients who require more aggressive lipid-lowering treatment.

Arterial stiffness and peripheral arterial disease in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is associated with increased cardiovascular risk. We aimed to evaluate arterial stiffness and the ankle brachial index (ABI), two markers of subclinical cardiovascular disease, in SLE. We studied 55 patients with SLE (12.7% males, age 53.3 ± 15.3 years) and 61 age- and gender-matched controls. Arterial stiffness was evaluated by measuring pulse wave velocity (PWV), augmentation index (AIx) and central systolic, diastolic, pulse and mean blood pressure (BP). Peripheral arterial disease was defined as ABI ≤ 0.90. Regarding markers of arterial stiffness, patients with SLE had lower PWV and AIx than controls (p < 0.01 and p < 0.05, respectively). However, after adjusting for differences in cardiovascular risk factors between patients with SLE and controls, PWV and AIx did not differ between the two groups. Central systolic, diastolic, pulse and mean BP also did not differ between the two groups. In patients with SLE, PWV correlated independently with systolic BP (B = 0.05, p < 0.001) and waist/hip ratio (B = 6.72, p < 0.05). Regarding ABI, the lowest ABI was lower in patients with SLE than in controls (p < 0.005). However, after adjusting for differences in cardiovascular risk factors between patients with SLE and controls, the lowest ABI did not differ between the two groups. The prevalence of PAD also did not differ between patients with SLE and controls (10.0 and 5.4%, respectively; p = NS). Markers of arterial stiffness and the ABI do not appear to differ between patients with SLE and age- and gender-matched controls. However, given the small sample size, larger studies are needed to clarify whether SLE promotes arterial stiffness and PAD.

Lipid-lowering agents in the management of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in developed countries and is associated not only with increased risk for liver disease-related complications but also with higher cardiovascular morbidity. Accordingly, lipid-lowering agents are frequently considered in these patients to reduce cardiovascular risk. However, there have been concerns regarding the safety of these agents in patients with chronic liver diseases. In the present review, we discuss the safety of lipid-lowering agents in patients with NAFLD as well as their effects on both cardiovascular and liver disease in this population. Accumulating data suggest that statins are safe in patients with NAFLD and that they reduce the increased cardiovascular morbidity of this population. However, it is still unclear whether statins are also useful as a treatment for NAFLD per se, since there are very limited and conflicting data on their effects on liver histology. There is also very scarce evidence regarding the safety and efficacy of other lipid-lowering agents in patients with NAFLD. Randomized controlled studies are needed to evaluate the role of lipid-lowering agents and particularly statins for the prevention of both cardiovascular and liver disease-related complications in this high-risk population.

Impaired antioxidative activity of high-density lipoprotein is associated with more severe acute ischemic stroke

BACKGROUND/AIMS

High-density lipoprotein (HDL) has important anti-atherogenic functions, including antioxidant effects. However, it is unclear whether the antioxidative activity of HDL is associated with the severity and outcome of acute ischemic stroke. We aimed to evaluate this association.

METHODS

We prospectively studied 199 consecutive patients admitted with acute ischemic stroke and followed them up until discharge. We measured HDL antioxidant capacity, HDL-associated paraoxonase-1 (PON1) activity and HDL-associated myeloperoxidase (MPO) levels. Severe stroke was defined as National Institutes of Health Stroke Scale (NIHSS) at admission ≥5. Dependency was defined as modified Rankin scale at discharge between 2 and 5.

RESULTS

Patients with severe stroke had lower HDL antioxidant capacity, higher MPO levels and higher MPO/PON1 ratio. Independent risk factors for severe stroke were female gender (RR 2.80, 95% CI 1.37-5.70, p = 0.005), glucose levels (RR 1.01, 95% CI 1.0-1.02, p < 0.01) and HDL antioxidant capacity (RR 1.03, 95% CI 1.01-1.06, p < 0.05). Patients who were dependent at discharge had lower HDL antioxidant capacity, higher MPO levels and higher MPO/PON1 ratio. Independent predictors of dependency at discharge were lack of lipid-lowering treatment (RR 6.86, 95% CI 1.83-25.67, p < 0.005) and NIHSS (RR 1.56, 95% CI 1.29-1.88, p < 0.0001). The HDL antioxidant capacity did not differ between patients who died during hospitalization and those who were discharged. The only independent predictor of in-hospital mortality was NIHSS (RR 1.16, 95% CI 1.06-1.27, p < 0.005).

CONCLUSIONS

Impaired antioxidative activity of HDL is associated with more severe acute ischemic stroke and might also predict a worse functional outcome in these patients.

The role of statins for the primary and secondary prevention of coronary heart disease in women

Coronary heart disease (CHD) is the leading cause of death in the developed world in both men and women. Elevated low-density lipoprotein cholesterol (LDL-C) levels are strong and independent vascular risk factors in both genders. Statins effectively decrease LDL-C levels, reduce vascular morbidity and mortality and are an essential component of CHD preventive strategies. However, women are less likely to be prescribed statins than men in both primary and secondary prevention settings. It was argued that there is no conclusive evidence showing that statins are beneficial for the prevention of vascular disease in women, particularly in those without established CHD. This review summarizes the evidence regarding the effects of statins in the prevention of CHD in women. Accumulating data suggest that statins are equally effective in both men and women. The lack of significant effects in some studies appears to be primarily due to the under-representation of women and the ensuing lack of statistical power. Current guidelines for the prevention of vascular disease also recommend a similar management of dyslipidemia in both men and women. Therefore, statin treatment should be implemented with the same criteria and with the same goals in both genders.

Sex-specific differences in cardiovascular risk factors and blood pressure control in hypertensive patients

Cardiovascular disease (CVD) and cardiovascular risk factors are frequently undertreated in women. However, it is unclear whether the prevalence of additional cardiovascular risk factors and the total cardiovascular risk differ between hypertensive men and women. There are also limited data regarding rates of blood pressure control in the two sexes outside the United States. The authors aimed to compare the cardiovascular risk profile between sexes. A total of 1810 hypertensive patients (40.4% men, age 56.5±13.5 years) attending the hypertension outpatient clinic of our department were studied. Men were more frequently smokers than women and were more heavy smokers than the latter. Serum high-density lipoprotein cholesterol levels were lower and serum triglyceride levels were higher in men. On the other hand, abdominal obesity and chronic kidney disease were more prevalent in women. The estimated cardiovascular risk was higher in men than in women but the prevalence of established CVD did not differ between the sexes. The percentage of patients with controlled hypertension and the number of antihypertensive medications were similar in men and women. In conclusion, hypertensive men have more adverse cardiovascular risk factor profile and greater estimated cardiovascular risk than women. However, the prevalence of established CVD does not differ between sexes. These findings further reinforce current guidelines that recommend that management of hypertension and of other cardiovascular risk factors should be as aggressive in women as in men in order to prevent cardiovascular events.

Colesevelam: a new and improved bile acid sequestrant?

Treatment with statins represents an essential component both of primary and secondary cardiovascular prevention strategies. However, a proportion of patients cannot reach low-density lipoprotein cholesterol (LDL-C) targets with the highest tolerable dose of a potent statin or is intolerant to statins. Several treatment options are available for these patients. Colesevelam is a relatively new bile acid sequestrant that decreases serum LDL-C levels. Moreover, colesevelam improves glycemic control and seems to be well-tolerated, at least in short-term studies. Therefore, colesevelam seems to be a useful tool for the management of high-risk patients who cannot achieve LDL-C targets with monotherapy with a potent statin.

Secondary Hypertension: Novel Insights

It is estimated that 5-10% of hypertensive patients have secondary hypertension. The main causes of secondary hypertension are parenchymal renal disease, primary aldosteronism and renovascular hypertension. The identification of these patients is important because it enables the etiological management of the underlying disease and in some cases leads to blood pressure control without antihypertensive medications. On the other hand, diagnostic evaluation for secondary hypertension often includes complex and expensive tests and should be performed only in patients with a strong clinical suspicion for its presence. If preliminary screening tests suggest the presence of secondary hypertension, these patients should be referred to specialized centers for further diagnostic evaluation and comprehensive management.

Comparative effects of more versus less aggressive treatment with statins on the long-term outcome of patients with acute ischemic stroke

BACKGROUND AND AIMS

There are no studies that compared the effects of different intensities of statin treatment on the long-term outcome of patients with recent ischemic stroke. We aimed to evaluate these effects.

METHODS

We prospectively studied 436 consecutive patients who were discharged after acute ischemic stroke (39.2% males, age 78.6 ± 6.7 years). Statin treatment was categorized in equipotent doses of atorvastatin. One year after discharge, the functional status was assessed with the modified Rankin scale (mRS). Adverse outcome was defined as mRS between 2 and 6. The occurrence of ischemic stroke, myocardial infarction and death was recorded.

RESULT

Adverse outcome rates were lower in patients treated with atorvastatin 20 mg/day or more potent doses of statins than in patients treated with atorvastatin 10 mg/day (63.5, 38.2 and 48.2%, respectively; p = 0.004). In binary logistic regression analysis, independent predictors of adverse outcome were the mRS at discharge (relative risk (RR) 2.33, 95% confidence interval (CI) 1.77-3.07, p < 0.001) whereas more aggressive treatment with statins independently predicted favorable outcome (atorvastatin 20 vs. 10 mg/day, RR 0.30, 95% CI 0.11-0.87, p = 0.026; atorvastatin 40 mg/day or more potent dose of statins vs. atorvastatin 10 mg/day, RR 1.66, 95% CI 0.62-4.44, p = NS). The incidence of cardiovascular events and all-cause mortality showed a trend for being lower in patients treated with atorvastatin 40-80 mg/day or rosuvastatin 10-40 mg/day than in those treated with less potent doses of statins.

CONCLUSION

More aggressive statin treatment improves the long-term functional outcome of patients with acute ischemic stroke more than less aggressive treatment.

Prior treatment with dipeptidyl peptidase 4 inhibitors is associated with better functional outcome and lower in-hospital mortality in patients with type 2 diabetes mellitus admitted with acute ischaemic stroke

It is unclear whether prior antidiabetic treatment affects stroke severity and outcome. To evaluate this association, we prospectively studied all patients who were admitted in our Department with acute ischaemic stroke (n = 378, mean age = 78.8 ± 6.5 years). The severity of stroke was assessed at admission with the National Institutes of Health Stroke Scale. The outcome was assessed with the modified Rankin Scale at discharge and with in-hospital mortality. A total of 123 patients had type 2 diabetes mellitus. At admission, there was a trend for lower National Institutes of Health Stroke Scale in patients treated with dipeptidyl peptidase 4 inhibitors compared with patients treated with other antidiabetic agents (6.1 ± 7.5 vs 10.0 ± 9.2, respectively; p = 0.079). At discharge, patients treated with dipeptidyl peptidase 4 inhibitors had lower modified Rankin Scale than patients treated with other antidiabetic agents (2.1 ± 1.9 vs 3.2 ± 2.1, respectively; p < 0.05). Patients treated with dipeptidyl peptidase 4 inhibitors also had lower in-hospital mortality than patients treated with other antidiabetic agents (0.0% vs 15.1%, respectively; p < 0.05). In conclusion, prior treatment with dipeptidyl peptidase 4 inhibitors in patients with acute ischaemic stroke appears to be associated with better functional outcome and lower mortality risk.

Management of statin-intolerant high-risk patients

Statins are an essential part of the management of patients at high vascular risk and are generally well-tolerated. However, statin intolerance will be observed more frequently as more stringent low density lipoprotein cholesterol (LDL-C) targets are pursued in an ever increasing number of patients. We review the management options for high-risk patients intolerant to statin treatment. Potential strategies include switching to a different statin, reducing the frequency of statin administration, substituting statins with other LDL-C-lowering agents (e.g. ezetimibe, colesevelam or nicotinic acid) and combining low-dose statin treatment with other lipid-modifying drugs. A limited number of studies specifically assessed statin-intolerant patients and most were small and of short duration. It is therefore difficult to make evidence-based recommendations for the management of this population. In addition, all treatment options have limitations in terms of safety and/or efficacy.

Increased augmentation index is paradoxically associated with lower in-hospital mortality in patients with acute ischemic stroke

OBJECTIVE

To evaluate the association between arterial stiffness and stroke severity and in-hospital outcome in patients admitted with acute ischemic stroke.

METHODS

We prospectively studied 415 consecutive patients who were admitted with acute ischemic stroke (39.5% males, age 78.8 ± 6.6 years). On the third day of hospitalization, the following markers of arterial stiffness were recorded: central systolic blood pressure (cSBP), diastolic BP (cDBP), mean pressure (cMP), pulse pressure (cPP), augmentation index (AIx) and pulse wave velocity (PWV). The severity of stroke was assessed on admission with the National Institutes of Health Stroke Scale (NIHSS) score. The outcome was evaluated with rates of dependency at discharge (modified Rankin scale score between 2 and 5) and in-hospital mortality.

RESULTS

None of the markers of arterial stiffness showed significant correlation with the NIHSS score on admission. However, there was a trend for an inverse correlation with AIx (r = -0.142, p = 0.064) and for a positive correlation with PWV (r = 0.235, p = 0.054). None of the markers of arterial stiffness differed between patients who were dependent at discharge and those who were independent. Patients who died during hospitalization had higher cDBP and cMP but lower cPP and AIx than patients who were discharged. In binary logistic regression analysis, independent predictors of in-hospital mortality were NIHSS score on admission (relative risk (RR) 1.16, 95% confidence interval (CI) 1.08-1.25, p < 0.001), presence of atrial fibrillation (RR 6.41, 95% CI 1.37-29.93, p = 0.018) and AIx (RR 0.94, 95% CI 0.89-0.99, p = 0.030).

CONCLUSIONS

Increased AIx appears to be associated with lower in-hospital mortality rates in elderly patients with acute ischemic stroke. Other markers of arterial stiffness do not appear to be associated with short-term outcome in this population.

Dyslipidemia induced by drugs used for the prevention and treatment of vascular diseases

Dyslipidemia is a major vascular risk factor. Interestingly, several agents used for the prevention and treatment of vascular diseases have an adverse effect on the lipid profile. In addition, agents belonging to the same class (e.g. beta blockers) can have significantly different actions on lipid levels. We summarize the effects of drugs used for the prevention and treatment of vascular diseases on the lipid profile. These effects should be considered when selecting a specific agent, particularly in high-risk patients.

Omega-3 fatty acids: how can they be used in secondary prevention?

Omega-3 fatty acids (FAs) are divided into long-chain fatty acids (eicosapentaenoic acid and docosahexaenoic acid ), which are found in fatty fish, and intermediate-chain FAs (alpha-linolenic acid), which are found in vegetable oils. Omega-3 FAs favorably modulate a variety of vascular risk factors and also exert antiarrhythmic effects. Epidemiologic data suggest that increased consumption of marine omega-3 FAs is associated with reduced coronary heart disease (CHD) mortality. Randomized controlled studies also show that supplementation with EPA and DHA reduces CHD risk, primarily in the secondary prevention setting. Data are more limited on the efficacy of marine omega-3 FAs for the primary prevention of CHD and on the role of alpha-linolenic acid. Increased intake of EPA and DHA represents a valuable tool for vascular disease prevention and should be recommended in all patients with CHD.

Established and emerging vascular risk factors and the development of aortic stenosis: an opportunity for prevention?

BACKGROUND

Aortic stenosis (AS) is the commonest valvular heart disease in the developed world. It is becoming increasingly accepted that the pathogenesis of AS and of its preceding abnormalities, aortic valve sclerosis (AVS) and aortic valve calcification (AVC), shares many characteristics with the atherosclerotic process.

OBJECTIVE

To assess the contribution of established and emerging vascular risk factors in the development of AS and to evaluate the potential of pharmacological intervention to modify the natural history of AS.

METHODS

We reviewed the epidemiological data that link AS and atherosclerosis and studies of vasculoprotective agents in patients with AS.

RESULTS/CONCLUSIONS

AS, AVS and AVC share many common risk factors with atherosclerosis and are possible markers of preclinical vascular disease. Statins appear to delay the progression of AS. However, more studies are needed before introducing such pharmacologic treatment for AS. The future may point towards targeted prevention of AS.

Predictive value of the ankle brachial index in patients with acute ischemic stroke

Background: Peripheral arterial disease (PAD) is frequently present in patients with acute ischemic stroke. However, there are limited data regarding the association between ankle brachial index (ABI) ≤ 0.90 (which is diagnostic of PAD) or > 1.40 (suggesting calcified arteries) and the severity of stroke and in-hospital outcome in this population. We aimed to evaluate these associations in patients with acute ischemic stroke. Patients and methods: We prospectively studied 342 consecutive patients admitted for acute ischemic stroke (37.4 % males, mean age 78.8 ± 6.4 years). The severity of stroke was assessed with the National Institutes of Health Stroke Scale (NIHSS)and the modified Rankin scale (mRS) at admission. The outcome was assessed with the mRS and dependency (mRS 2 - 5) at discharge and in-hospital mortality. Results: An ABI ≤ 0.90 was present in 24.6 % of the patients whereas 68.1 % had ABI 0.91 - 1.40 and 7.3 % had ABI > 1.40. At admission, the NIHSS score did not differ between the 3 groups (10.4 ± 10.6, 8.3 ± 9.3 and 9.3 ± 9.4, respectively). The mRS score was also comparable in the 3 groups (3.6 ± 1.7, 3.1 ± 1.8 and 3.5 ± 2.3, respectively). At discharge, the mRS score did not differ between the 3 groups (2.9 ± 2.2, 2.3 ± 2.1 and 2.7 ± 2.5, respectively) and dependency rates were also comparable (59.5, 47.6 and 53.3 %, respectively). In-hospital mortality was almost two-times higher in patients with ABI ≤ 0.90 than in patients with ABI 0.91 - 1.40 or > 1.40 but this difference was not significant (10.9, 6.6 and 6.3 %, respectively). Conclusions: An ABI ≤ 0.90 or > 1.40 does not appear to be associated with more severe stroke or worse in-hospital outcome in patients with acute ischemic stroke.

Obesity and Outcome of Assisted Reproduction in Patients With Polycystic Ovary Syndrome

Assisted reproduction, including in vitro fertilization and intracytoplasmic sperm injection, is increasingly being used for the management of infertility in patients with polycystic ovary syndrome (PCOS). However, there are limited data regarding the association between obesity and the outcome of assisted reproduction in this specific population as well as on the effects of weight loss. The aim of the present review is to summarize the existing evidence on the association between obesity and the outcome of assisted reproduction in patients with PCOS. Accumulating data suggest that obesity is associated with lower pregnancy and live birth rates in patients with PCOS who are undergoing assisted reproduction therapy. However, it remains unclear whether weight loss improves the outcome of this therapy. Notably, recent guidelines state that the health benefits of postponing pregnancy to achieve weight loss must be balanced against the risk of declining fertility with advancing age. Therefore, if weight loss is not achieved within a reasonable time period, assisted reproduction therapy should be offered in adequately selected patients with PCOS, regardless of the presence of obesity.

Effects of lipid-lowering agents on inflammation, haemostasis and blood pressure

In addition to the modification of the lipid profile, most lipid-lowering agents appear to modulate other atherogenic pathways. We summarize the effects of lipid-lowering agents on inflammation, hemostasis and blood pressure. We also discuss the potential contribution of these actions on cardiovascular disease prevention. Most lipid-lowering agents appear to exert anti-inflammatory, antithrombotic and antihypertensive effects. These pleiotropic actions appear to contribute to the reduction in cardiovascular events and deep venous thrombosis during statin treatment. Regarding other lipid-lowering agents, it is unclear whether their effects on inflammation, thrombosis or blood pressure play a role in their antiatherogenic potential.

Adequacy of preadmission oral anticoagulation with vitamin K antagonists and ischemic stroke severity and outcome in patients with atrial fibrillation

It is unclear whether vitamin K antagonists affect stroke severity and outcome in patients with atrial fibrillation (AF). We aimed to evaluate this association. We prospectively studied 539 consecutive patients admitted with acute ischemic stroke (41.2 % males, age 78.9 ± 6.6 years). The severity of stroke was assessed at admission with the National Institutes of Health Stroke Scale (NIHSS). The outcome was assessed with dependency rates at discharge (modified Rankin scale 2-5) and with in-hospital mortality. 177 patients had a history of AF. The median NIHSS at admission did not differ between patients on acenocoumarol with INR 2.0-3.0, on acenocoumarol with INR < 2.0, on single antiplatelet treatment, on dual antiplatelet treatment, or on no treatment [4 (range 0-26), 13 (0-39), 8 (0-33), 3 (2-23) and 7 (0-33), respectively; p = 0.433]. Dependency rates were lower in patients on acenocoumarol with INR 2.0-3.0 or on dual antiplatelet treatment than in those on acenocoumarol with INR < 2.0, single antiplatelet treatment, or no treatment (20.0, 22.2, 61.5, 58.7 and 68.0 %, respectively; p = 0.024). Independent predictors of dependency were age, NIHSS at admission and history of ischemic stroke. In-hospital mortality did not differ between patients on acenocoumarol with INR 2.0-3.0, on acenocoumarol with INR < 2.0, on single antiplatelet treatment, on dual antiplatelet treatment, or on no treatment (7.7, 18.2, 16.1, 16.7 and 22.2 %, respectively; p = 0.822). In conclusion, optimally anticoagulated patients with AF have more favorable functional outcome after stroke and a trend for less severe stroke whereas patients with subtherapeutic anticoagulation have similar stroke severity and outcome with those on no treatment.