Clinical benefit from pharmacological elevation of high-density lipoprotein cholesterol: meta-regression analysis

Clinical, Demographic, and Biochemical Characteristics of Patients with Acute ST-Segment Elevation Myocardial Infarction: An Analysis of Acute Coronary Syndrome Registry Data of a Single Medical Center from 2005 to 2016

Background

ST-segment elevation myocardial infarction (STEMI) is one of the leading causes of morbidity and mortality in developed countries. Therefore, understanding the prevalence and trends of major risk factors may facilitate primary and secondary prevention of STEMI.

Methods

In the present study, 2446 consecutive patients with STEMI admitted to Far Eastern Memorial Hospital from 2005 to 2016 were enrolled. A comprehensive analysis of the prevalence, distribution, and trends over time of major risk factors as well as Framingham risk scores of all patients was performed.

Results

The most prevalent risk factors were male sex, hypertension (HTN), smoking, age, dyslipidemia, and diabetes mellitus. Furthermore, 95%-97% of the patients had at least one modifiable risk factor, and < 1% of the patients did not have any identifiable risk factors. The prevalence trends of smoking, HTN, dyslipidemia, and metabolic syndrome increased significantly from 2005 to 2016. Seasonal variation analysis revealed a 15% increase in STEMI cases between January and March compared with those between April and December. Isolated low high- density lipoprotein-cholesterol syndrome was the second most common type of dyslipidemia, with a prevalence rate of 16.6%. Moreover, only 56.8% of the male and 32% of the female patients were in the Framingham high-risk group.

Conclusions

A high prevalence rate and an increasing trend of modifiable risk factors resulted in a high number of STEMI cases at our hospital. Controlling modifiable risk factors and improving nontraditional risk factor detection could facilitate primary and secondary preventions for STEMI.

Administration of eicosapentaenoic acid may alter high-density lipoprotein heterogeneity in statin-treated patients with stable coronary artery disease: A 6-month randomized trial

BACKGROUND

Combined statin plus eicosapentaenoic acid (EPA) therapy might be a potentially effective treatment option to prevent coronary artery disease (CAD). The serum EPA/arachidonic acid (AA) ratio has been identified as a potential new risk marker for CAD. Few data exist whether administration of EPA could affect high-density lipoprotein (HDL) particle size. We hypothesized that the addition of EPA to ongoing statin therapy may result in altered HDL heterogeneity.

METHODS

We conducted this 6-month, single-center, prospective, randomized open-label clinical trial to investigate the effect of the additional administration of EPA on the HDL heterogeneity (HDL₂, HDL_3, and HDL₂/HDL₃ ratio) in stable CAD patients receiving treatment with statins. We assigned stable CAD patients already receiving statin therapy to the EPA group (1800mg/day: n=50) or the control group (n=50).

RESULTS

A significant decrease in the serum HDL₃ level (-4.7% vs. -0.5%, p=0.037), but not of the serum HDL₂ level, and a significant increase in the HDL₂/HDL₃ ratio (5.5% vs. -5.1%, p=0.032) were observed in the EPA group as compared to the control group. Multiple regression analysis with adjustments for coronary risk factors identified the achieved EPA/ AA ratio as an independent and significant predictor of an increase of the HDL₂/HDL₃ ratio (β=0.295, p=0.001). Furthermore, the change in the serum cholesterol ester transfer protein mass was positively correlated with the change in the EPA/AA ratio in the EPA group (r=0.286, p=0.044), but not in the control group (r=0.121, p=0.401).

CONCLUSION

Administration of EPA might decrease the serum HDL₃ level, resulting in an increase in the HDL₂/HDL₃ ratio. Furthermore, increased EPA/AA ratio by the addition of EPA to ongoing statin therapy might be an indicator of an increase in the HDL₂/HDL₃ ratio, thereby regulating HDL particle size.

CLINICAL TRIAL REGISTRATION

UMIN (http://www.umin.ac.jp/) Study ID: UMIN000010452.

Probabilistic Quantitative Assessment of Coronary Heart Disease Risk From Dietary Exposure to Industrially Produced Trans-Fatty Acids in Partially Hydrogenated Oils

We conducted a probabilistic evaluation of changes in coronary heart disease (CHD) risk and public health burdens from industrially produced trans-fatty acids (IP-TFAs) exposure from the uses of partially hydrogenated oils in food. Our analyses used four quantitative methods based on human studies considering the uncertainty associated with risk parameters for CHD and IP-TFA daily dietary exposure of 0.05% of energy. Method 1 used experimental controlled feeding trial data for changes in low-density lipoprotein cholesterol; Method 2 used changes in both low-density lipoprotein cholesterol and high-density lipoprotein cholesterol; Method 3 used changes in a combination of three emerging CHD risk factor biomarkers; and method 4 used prospective observational studies of CHD cases associated with long-term dietary exposure of trans-fatty acids. We estimated mean percent changes in CHD risk and annual CHD cases in U.S. adults, with lower and upper 95% uncertainty intervals. Our results show that consuming 0.05% of energy from IP-TFA, instead of cis-monounsaturated fatty acids, can cause annual mean increases in CHD cases of 814 (510–1151, method 1), 1502 (990–2043, method 2), or 6877 (3611–10 694, method 4) in U.S. adults. Results for method 3 were intermediate between those for methods 2 and 4. Sensitivity analyses using alternate risk parameters or an alternate exposure scenario resulted in minor changes in public health burden estimates. The results demonstrate that IP-TFA exposure as low as 0.05% of energy from partially hydrogenated oil uses in food can cause substantial public health burdens in the United States from increased CHD risk.

Effect of Niacin on Carotid Atherosclerosis in Patients at Low-Density Lipoprotein-Cholesterol Goal but High Lipoprotein (a) Level: a 2-Year Follow-Up Study

Objective

To examine the effect of niacin on the progression of carotid intima-media thickness (IMT) in patients with high level of lipoprotein (Lp) (a).

Methods

Patients at low-density lipoprotein-cholesterol goal but with Lp (a) >25 mg/dL and mean carotid IMT >0.75 mm were included. Eligible patients were randomized at a 1:2 ratio into one of two groups for 24 months: control or 1,500 mg extended release niacin. The primary study outcomes were the percentage changes in mean and maximal carotid IMT. The percentage change in lipid profiles including Lp (a) was analyzed as a secondary study outcome.

Results

Among 96 randomized patients, 31 completed the study (mean age: 65 years; male: 44%). At follow-up, the percentage change in mean carotid IMT was not significantly different between the two groups (−1.4%±15.5% and −1.1%±7.3% in the control and niacin groups, respectively, p=0.95). The percentage change in maximal carotid IMT was also similar in the two groups (0.7%±16.5% and −4.4%±11.6%, respectively, p=0.35). Elevation of high-density lipoprotein-cholesterol tended to be higher in the niacin group (p=0.07), and there was a significant difference in the percentage change in hemoglobin A1c between the two groups (−1.9%±2.2% and 3.3%±6.7%, respectively, p=0.02). Reduction of Lp (a) was greater in the niacin-treated group compared to placebo, but the difference was not statistically significant.

Conclusion

Treatment with niacin for two years did not inhibit the progression of carotid intima-media thickening in patients with high Lp (a) level. However, this study may have been underpowered to evaluate the primary study outcome.

Niacin for primary and secondary prevention of cardiovascular events

BACKGROUND

Nicotinic acid (niacin) is known to decrease LDL-cholesterol, and triglycerides, and increase HDL-cholesterol levels. The evidence of benefits with niacin monotherapy or add-on to statin-based therapy is controversial.

OBJECTIVES

To assess the effectiveness of niacin therapy versus placebo, administered as monotherapy or add-on to statin-based therapy in people with or at risk of cardiovascular disease (CVD) in terms of mortality, CVD events, and side effects.

SEARCH METHODS

Two reviewers independently and in duplicate screened records and potentially eligible full texts identified through electronic searches of CENTRAL, MEDLINE, Embase, Web of Science, two trial registries, and reference lists of relevant articles (latest search in August 2016).

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that either compared niacin monotherapy to placebo/usual care or niacin in combination with other component versus other component alone. We considered RCTs that administered niacin for at least six months, reported a clinical outcome, and included adults with or without established CVD.

DATA COLLECTION AND ANALYSIS

Two reviewers used pre-piloted forms to independently and in duplicate extract trials characteristics, risk of bias items, and outcomes data. Disagreements were resolved by consensus or third party arbitration. We conducted random-effects meta-analyses, sensitivity analyses based on risk of bias and different assumptions for missing data, and used meta-regression analyses to investigate potential relationships between treatment effects and duration of treatment, proportion of participants with established coronary heart disease and proportion of participants receiving background statin therapy. We used GRADE to assess the quality of evidence.

MAIN RESULTS

We included 23 RCTs that were published between 1968 and 2015 and included 39,195 participants in total. The mean age ranged from 33 to 71 years. The median duration of treatment was 11.5 months, and the median dose of niacin was 2 g/day. The proportion of participants with prior myocardial infarction ranged from 0% (4 trials) to 100% (2 trials, median proportion 48%); the proportion of participants taking statin ranged from 0% (4 trials) to 100% (12 trials, median proportion 100%).Using available cases, niacin did not reduce overall mortality (risk ratio (RR) 1.05, 95% confidence interval (CI) 0.97 to 1.12; participants = 35,543; studies = 12; I2 = 0%; high-quality evidence), cardiovascular mortality (RR 1.02, 95% CI 0.93 to 1.12; participants = 32,966; studies = 5; I2 = 0%; moderate-quality evidence), non-cardiovascular mortality (RR 1.12, 95% CI 0.98 to 1.28; participants = 32,966; studies = 5; I2 = 0%; high-quality evidence), the number of fatal or non-fatal myocardial infarctions (RR 0.93, 95% CI 0.87 to 1.00; participants = 34,829; studies = 9; I2 = 0%; moderate-quality evidence), nor the number of fatal or non-fatal strokes (RR 0.95, 95% CI 0.74 to 1.22; participants = 33,661; studies = 7; I2 = 42%; low-quality evidence). Participants randomised to niacin were more likely to discontinue treatment due to side effects than participants randomised to control group (RR 2.17, 95% CI 1.70 to 2.77; participants = 33,539; studies = 17; I2 = 77%; moderate-quality evidence). The results were robust to sensitivity analyses using different assumptions for missing data.

AUTHORS' CONCLUSIONS

Moderate- to high-quality evidence suggests that niacin does not reduce mortality, cardiovascular mortality, non-cardiovascular mortality, the number of fatal or non-fatal myocardial infarctions, nor the number of fatal or non-fatal strokes but is associated with side effects. Benefits from niacin therapy in the prevention of cardiovascular disease events are unlikely.

Re-evaluation of cholesteryl ester transfer protein function in atherosclerosis based upon genetics and pharmacological manipulation

PURPOSE OF REVIEW

To re-evaluate the functions of plasma cholesteryl ester transfer protein (CETP) in atherosclerosis based upon recent findings from human genetics and pharmacological CETP manipulation.

RECENT FINDINGS

CETP is involved in the transfer of cholesteryl ester from HDL to apolipoprotein B-containing lipoproteins, a key step of reverse cholesterol transport (RCT). CETP inhibitors have been developed to raise serum HDL-cholesterol (HDL-C) levels and reduce cardiovascular events. However, outcome studies of three CETP inhibitors (torcetrapib, dalcetrapib and evacetrapib) were prematurely terminated because of increased mortality or futility despite marked increases in HDL-cholesterol and decreases in LDL-cholesterol except for dalcetrapib. Patients with CETP deficiency show remarkable changes in HDL and LDL and are sometimes accompanied by atherosclerotic cardiovascular diseases. Recent prospective epidemiological studies demonstrated atheroprotective roles of CETP. CETP inhibition induces formation of small dense LDL and possibly dysfunctional HDL and downregulates hepatic scavenger receptor class B type I (SR-BI). Therefore, CETP inhibitors may interrupt LDL receptor and SR-BI-mediated cholesterol delivery back to the liver.

SUMMARY

For future drug development, the opposite strategy, namely enhancers of RCT via CETP and SR-BI activation as well as the inducers of apolipoprotein A-I or HDL production might be a better approach rather than delaying HDL metabolism by inhibiting a main stream of RCT in vivo.

Cholesteryl ester transfer protein (CETP) I405V polymorphism and cardiovascular disease in eastern European Caucasians - a cross-sectional study

Background

The cholesteryl ester transfer protein (CETP) polymorphism I405V has been suggested to be involved in longevity and susceptibility to cardiovascular diseases. An enhanced reverse cholesterol transport due to enhanced HDL levels has been hypothesized to be the underlying mechanism. However, clinical trials with HDL-enhancing drugs failed to show beneficial effects. Consequently, it has been postulated that genetic variations enhancing HDL levels are cardioprotective only if they also decrease LDL levels.

Methods

A cross-sectional study was conducted to genotype 1028 healthy blood donors and 1517 clinically well characterized elderly for CETP I405V.

Results

We could not find any association of this polymorphism with age for both, males or females, in any of these cohorts (P = 0.71 and P = 0.57, respectively, for males and P = 0.55 and P = 0.88, respectively, for females). In addition, no association with cardiovascular diseases could be observed in the elderly cohort (males OR = 1.12 and females OR = 0.88). In the same cohort, the CETP V405V genotype was associated with significantly enhanced HDL levels (P = 0.03), mostly owing to the female sex (P = 0.46 for males, P = 0.02 for females), whereas LDL and triglyceride levels were unchanged (P = 0.62 and P = 0.18, respectively).

Conclusion

Our data support the recent hypothesis that variations enhancing HDL levels without affecting LDL levels are not associated with the risk for cardiovascular diseases.

Lifestyle intervention enhances high-density lipoprotein function among patients with metabolic syndrome only at normal low-density lipoprotein cholesterol plasma levels

BACKGROUND

Metabolic syndrome (MetS) is associated with altered lipoprotein metabolism and impairment in the functionality of small, dense high-density lipoprotein (HDL) particles secondary to compositional alterations.

OBJECTIVE

The objective of this study was to investigate the capacity of a lifestyle program to improve the composition and antioxidative function (AOX) of small dense HDL3c in MetS.

METHODS

Patients with MetS (n = 33) not taking lipid-lowering drugs were recruited to follow a 12-week educational program to reduce caloric intake and to increase physical activity. HDL subfractions were preparatively isolated by isopycnic density-gradient ultracentrifugation. AOX of HDL3c was assessed as its capacity to inhibit low-density lipoprotein oxidation induced by an azoinitiator.

RESULTS

AOX of HDL3c was significantly improved (mean reduction in the propagation rate of low-density lipoprotein oxidation by HDL3c, -6.8%, P = .03) and systemic oxidative stress, assessed as plasma levels of 8-isoprostanes, tended to decrease in normocholesterolemic MetS patients (low-density lipoprotein cholesterol [LDL-C] < 130 mg/dL) but not in patients with elevated LDL-C levels and in the whole study population. In both the whole study population and the normocholesterolemic subgroup, lifestyle intervention resulted in a significant degree of normalization of HDL3c composition, (enrichment in apolipoprotein A-I and cholesteryl esters, depletion in triglycerides), which was more pronounced at LDL-C < 130 mg/dL.

CONCLUSION

In patients with MetS, a lifestyle program improves AOX of small, dense HDL in subjects with normal LDL-C levels. Correction of HDL composition, involving partial normalization of apoA-I content and core lipid composition, 2 central features of the lipid hydroperoxide-inactivating capacity of HDL, may account for this effect.