Prediction of Cardiovascular Risk Using Framingham,ASSIGN and QRISK2: How Well Do They Predict Individual Rather than Population Risk?

Background

The objective of this study was to evaluate the performance of risk scores (Framingham, Assign and QRISK2) in predicting high cardiovascular disease (CVD) risk in individuals rather than populations.

Methods and findings

This study included 1.8 million persons without CVD and prior statin prescribing using the Clinical Practice Research Datalink. This contains electronic medical records of the general population registered with a UK general practice. Individual CVD risks were estimated using competing risk regression models. Individual differences in the 10-year CVD risks as predicted by risk scores and competing risk models were estimated; the population was divided into 20 subgroups based on predicted risk. CVD outcomes occurred in 69,870 persons. In the subgroup with lowest risks, risk predictions by QRISK2 were similar to individual risks predicted using our competing risk model (99.9% of people had differences of less than 2%); in the subgroup with highest risks, risk predictions varied greatly (only 13.3% of people had differences of less than 2%). Larger deviations between QRISK2 and our individual predicted risks occurred with calendar year, different ethnicities, diabetes mellitus and number of records for medical events in the electronic health records in the year before the index date. A QRISK2 estimate of low 10-year CVD risk (<15%) was confirmed by Framingham, ASSIGN and our individual predicted risks in 89.8% while an estimate of high 10-year CVD risk (≥20%) was confirmed in only 48.6% of people. The majority of cases occurred in people who had predicted 10-year CVD risk of less than 20%.

Conclusions

Application of existing CVD risk scores may result in considerable misclassification of high risk status. Current practice to use a constant threshold level for intervention for all patients, together with the use of different scoring methods, may inadvertently create an arbitrary classification of high CVD risk.     

Co-Morbidity,Ageing and Predicted Mortality in Antiretroviral Treated Australian Men: A Quantitative Analysis

Background

Life expectancy has increased in HIV-positive individuals receiving combination antiretroviral therapy (cART); however, they still experience increased mortality due to ageing-associated comorbidities compared with HIV-negative individuals.

Methods

A retrospective study of 314 Queensland HIV-infected males on cART was conducted. The negative impact of ageing was assessed by estimating the probability of 5-year mortality; comparisons were made between an HIV-specific predictive tool (VACS index) and the Australian Bureau of Statistics (ABS) life-tables to examine potential differences attributed to HIV. The negative impact of ageing was also assessed by the prevalence of comorbidities. Associations between comorbidity and estimates of predicted mortality by regression analysis were assessed.

Results

The mean predicted 5-year mortality rate was 6% using the VACS index compared with 2.1% using the ABS life-table (p<0.001). The proportion of patients at predicted high risk of mortality (>9%) using the VACS index or ABS life-table were 17% and 1.8% respectively. Comorbidities were also more prevalent in this cohort compared with rates of comorbidities in age-matched Australian men from the general population. Metabolic disease (38.2%) was the most prevalent comorbidity followed by renal (33.1%) and cardiovascular disease (23.9%). Multivariate analysis demonstrated that patients with a history of cardiovascular disease had a higher predicted risk of mortality (OR=1.69;95%CI:1.17-2.45) whereas ex-smokers had a lower predicted risk of mortality (OR=0.61;95%CI:0.41-0.92).

Conclusions

Using the VACS Index there is an increased predicted risk of mortality in cART-treated HIV infected Australian men compared with age-matched men using the ABS data. This increased predicted mortality risk is associated with cardiovascular disease and the number of comorbidities per subject; which suggests that the VACS Index may discriminate between high and low predicted mortality risks in this population. However, until the VACS Index is validated in Australia this data may suggest the VACS Index overestimates predicted mortality risk in this country.     

The sense and nonsense of direct-to-consumer genetic testing for cardiovascular disease

Expectations are high that increasing knowledge of the genetic basis of cardiovascular disease will eventually lead to personalised medicine—to preventive and therapeutic interventions that are targeted to at-risk individuals on the basis of their genetic profiles. Most cardiovascular diseases are caused by a complex interplay of many genetic variants interacting with many non-genetic risk factors such as diet, exercise, smoking and alcohol consumption. Since several years, genetic susceptibility testing for cardiovascular diseases is being offered via the internet directly to consumers. We discuss five reasons why these tests are not useful, namely: (1) the predictive ability is still limited; (2) the risk models used by the companies are based on assumptions that have not been verified; (3) the predicted risks keep changing when new variants are discovered and added to the test; (4) the tests do not consider non-genetic factors in the prediction of cardiovascular disease risk; and (5) the test results will not change recommendations of preventive interventions. Predictive genetic testing for multifactorial forms of cardiovascular disease clearly lacks benefits for the public. Prevention of disease should therefore remain focused on family history and on non-genetic risk factors as diet and physical activity that can have the strongest impact on disease risk, regardless of genetic susceptibility.     

Aggressive lipid management for cardiovascular prevention: evidence from clinical trials

Epidemiologic evidence shows that elevated serum cholesterol, specifically low-density lipoprotein cholesterol (LDL-C), increases the risk of coronary heart disease (CHD). Moreover, large-scale intervention trials demonstrate that treatment with HMG-CoA reductase inhibitors (statins), the most effective drug class for lowering LDL-C, significantly reduces the risk of CHD events. Unfortunately, only a moderate percentage of hypercholesterolemic patients are achieving LDL-C targets specified by the National Cholesterol Education Program (NCEP), in part because clinicians are not effectively titrating medications as needed to achieve LDL-C goals. Recent evidence suggests that more aggressive LDL-C lowering may provide greater clinical benefit, even in individuals with moderately elevated serum cholesterol levels. Furthermore, recent studies suggest that statins have cardioprotective effects in many high-risk individuals, including those with baseline LDL-C <100 mg/dl. High-density lipoprotein cholesterol (HDL-C) was recognized by the NCEP-Adult Treatment Panel II (ATP II) as a negative risk factor for CHD. The NCEP-ATP III guidelines have also reaffirmed the importance of HDL-C by increasing the low HDL-C designation from <35 to <40 mg/dl as a major risk factor for CHD. Similarly, triglyceride control will play a larger role in dyslipidemia management. As more clinicians effectively treat adverse lipid and lipoprotein cardiovascular risk factors, patients will likely benefit from reductions in cardiovascular events.     

Genetic analysis of breast cancer in the cancer and steroid hormone study.

The familial risk of breast cancer is investigated in a large population-based, case-control study conducted by the Centers for Disease Control. The data set is based on 4,730 histologically confirmed breast cancer cases aged 20 to 54 years and on 4,688 controls who were frequency matched to cases on the basis of both geographic region and 5-year categories of age, and it includes family histories, obtained through interviews of cases and controls, of breast cancer in mothers and sisters. Segregation analysis and goodness-of-fit tests of genetic models provide evidence for the existence of a rare autosomal dominant allele (q = .0033) leading to increased susceptibility to breast cancer. The effect of genotype on the risk of breast cancer is shown to be a function of a woman's age. Although, compared with noncarriers, carriers of the allele appear to be at greater risk at all ages, the ratio of age-specific risks is greatest at young ages and declines steadily thereafter. The proportion of cases predicted to carry the allele is highest (36%) among cases aged 20-29 years. This proportion gradually decreases to 1% among cases aged 80 years or older. The cumulative lifetime risk of breast cancer for women who carry the susceptibility allele is predicted to be high, approximately 92%, while the cumulative lifetime risk for noncarriers is estimated to be approximately 10%.     

Statin therapy for prevention and treatment of acute and chronic cardiovascular disease: update on recent trials and metaanalyses

PURPOSE OF REVIEW: To summarize the evidence from recent clinical trials and metaanalyses on the efficacy of statin therapy to reduce death, myocardial infarction and stroke, and to review the effects of statins in patients with low LDL cholesterol, diabetes, end-stage renal disease, and acute coronary syndrome. RECENT FINDINGS: In large metaanalyses of randomized controlled trials relative risk reductions from statins compared with placebo for patients with manifest or with risk factors for coronary artery disease were 13% for overall mortality, 26% for fatal and nonfatal myocardial infarction, and 18% for fatal and nonfatal stroke. Evidence from large trials suggests that patients with type II diabetes compared with patients without diabetes have similar risk reductions from statins for cardiovascular events, but this benefit is not seen in patients with diabetes and end-stage renal disease. In patients with acute coronary syndrome, early treatment with high-dose atorvastatin reduces cardiovascular morbidity after the first 4 months following the event, but the impact on mortality endpoints remains less clear. Results from recent trials in patients with stable coronary artery disease or type II diabetes suggest that statins provide benefit at considerable low LDL cholesterol levels. Therefore, target values for LDL cholesterol of less than 1.8 mmol/l (<70 mg/dl) should be considered for all patients with coronary artery disease or equivalent coronary risk. SUMMARY: For patients at high risk of coronary artery disease there is growing evidence for the concept of 'the lower, the better' regarding LDL cholesterol levels. Ongoing trials are further investigating the safety of lower target values in patients at various risk of coronary artery disease.     

Adding pharmacists to primary care teams reduces predicted long-term risk of cardiovascular events in Type 2 diabetic patients without established cardiovascular disease: results from a randomized trial

Aim To determine the impact of adding pharmacists to primary care teams on predicted 10-year risk of cardiovascular events in patients with Type?2 diabetes without established cardiovascular disease. Methods This was a pre-specified secondary analysis of randomized trial data. The main study found that, compared with usual care, addition of a pharmacist resulted in improvements in blood pressure, dyslipidaemia, and hyperglycaemia for primary care patients with Type?2 diabetes. In this sub-study, predicted 10-year risk of cardiovascular events at baseline and 1?year were calculated for patients free of cardiovascular disease at enrolment. The primary outcome was change in UK Prospective Diabetes Study (UKPDS) risk score; change in Framingham risk score was a secondary outcome. Results Baseline characteristics were similar between the 102 intervention patients and 93 control subjects: 59% women, median (interquartile range) age 57 (50-64) years, diabetes duration 3 (1-6.5) years, systolic blood pressure 128 (120-140) mmHg, total cholesterol 4.34 (3.75-5.04) mmol/l and HbA(1c) 54?mmol/mol (48-64?mmol/mol) [7.1% (6.5-8.0%)]. Median baseline UKPDS risk score was 10.2% (6.0-16.7%) for intervention patients and 9.5% (5.8-15.1%) for control subjects (P?=?0.80). One-year post-randomization, the median absolute reduction in UKPDS risk score was 1.0% greater for intervention patients compared with control subjects (P?=?0.032). Similar changes were seen with the Framingham risk score (median reduction 1.2% greater for intervention patients compared with control subjects, P?=?0.048). The two risk scores were highly correlated (rho?=?0.83; P?相似文献   

Elevated lipoprotein(a) as a predictor for coronary events in older men

Elevated circulating lipoprotein (a) [Lp(a)] is associated with an increased risk of first and recurrent cardiovascular events; however, the effect of baseline Lp(a) levels on long-term outcomes in an elderly population is not well understood. The current single-center prospective study evaluated the association of Lp(a) levels with incident acute coronary syndrome to identify populations at risk of future events. Lp(a) concentration was assessed in 755 individuals (mean age of 71.9 years) within the community and followed for up to 8 years (median time to event, 4.5 years; interquartile range, 2.5–6.5 years). Participants with clinically relevant high levels of Lp(a) (>50 mg/dl) had an increased absolute incidence rate of ASC of 2.00 (95% CI, 1.0041) over 8 years (P = 0.04). Moreover, Kaplan-Meier cumulative event analyses demonstrated the risk of ASC increased when compared with patients with low (<30 mg/dl) and elevated (30–50 mg/dl) levels of Lp(a) over 8 years (Gray’s test; P = 0.16). Within analyses adjusted for age and BMI, the hazard ratio was 2.04 (95% CI, 1.0–4.2; P = 0.05) in the high versus low Lp(a) groups. Overall, this study adds support for recent guidelines recommending a one-time measurement of Lp(a) levels in cardiovascular risk assessment to identify subpopulations at risk and underscores the potential utility of this marker even among older individuals at a time when potent Lp(a)-lowering agents are undergoing evaluation for clinical use.     

Differences in cardiovascular disease risk factors by weight history: the Aerobics Center Longitudinal Study

The objective of this study was to compare cardiovascular disease (CVD) risk factor levels in adults with a history of weight loss to levels in adults who did not lose weight, after both groups subsequently experienced an approximate 1-year interval of weight maintenance. Extant data from the Aerobics Center Longitudinal Study (ACLS) were used to identify 5,151 adults who were weight maintainers (maintained weight within ± 3.0% over two consecutive periods of ~1 year) or weight-loss maintainers (lost >3.0- <5.0% or ≥ 5.0% of body weight in the first interval and maintained that loss in the second interval). Mixed models regression was used to accommodate repeated measures and adjust for gender, age, smoking, cardiorespiratory fitness, decade of clinic visit, interval length, and BMI at the time of risk factor measurement. Coefficients from the model were used to calculate the adjusted risk factor levels in the three groups. Differences in total cholesterol (-3.8 mg/dl, 95% confidence interval: -5.5, -2.0), low-density lipoprotein (LDL) cholesterol (-3.0 mg/dl, confidence interval: -4.8, -1.1), triglycerides (-6.1 mg/dl, confidence interval: -10.6, -1.7) and diastolic blood pressure (-0.8 mg/dl, confidence interval: -1.4, -0.3) indicated that levels were slightly more favorable in the ≥ 5.0% weight-loss maintenance group than weight maintenance group. Levels were similar for glucose, high-density lipoprotein (HDL) cholesterol and systolic blood pressure. This work indicates that, when adjusted for covariates including current BMI, adults with a history of weight loss may have CVD risk factors to levels as good, or perhaps even better than, those observed in adults who maintain their weight.     

Flexible dose-response models for Japanese atomic bomb survivor data: Bayesian estimation and prediction of cancer risk

Generalised absolute risk models were fitted to the latest Japanese atomic bomb survivor cancer incidence data using Bayesian Markov Chain Monte Carlo methods, taking account of random errors in the DS86 dose estimates. The resulting uncertainty distributions in the relative risk model parameters were used to derive uncertainties in population cancer risks for a current UK population. Because of evidence for irregularities in the low-dose dose response, flexible dose-response models were used, consisting of a linear-quadratic-exponential model, used to model the high-dose part of the dose response, together with piecewise-linear adjustments for the two lowest dose groups. Following an assumed administered dose of 0.001 Sv, lifetime leukaemia radiation-induced incidence risks were estimated to be 1.11 x 10(-2) Sv(-1) (95% Bayesian CI -0.61, 2.38) using this model. Following an assumed administered dose of 0.001 Sv, lifetime solid cancer radiation-induced incidence risks were calculated to be 7.28 x 10(-2) Sv(-1) (95% Bayesian CI -10.63, 22.10) using this model. Overall, cancer incidence risks predicted by Bayesian Markov Chain Monte Carlo methods are similar to those derived by classical likelihood-based methods and which form the basis of established estimates of radiation-induced cancer risk.     

Reassessment of cardiovascular risk in diabetes

PURPOSE OF REVIEW: To review recent trials and reassess cardiovascular risk in people with diabetes. RECENT FINDINGS: Recent clinical trials have tended to focus on lower-risk participants with diabetes who have had event rates considerably lower than participants in the early lipid trials. Statin studies have generally shown benefit in those without cardiovascular disease and at lower levels of low-density lipoprotein cholesterol. Results of fibrate and glitazone studies have been mixed; the question of benefit among statin-treated patients remains unanswered. Investigators failed to confirm the benefits of glucose control observed in the original Diabetes Mellitus, Insulin Glucose Infusion in Acute Myocardial Infarction study possibly due to study design issues. Epidemiologic follow-up of the Diabetes Control and Complications Trial showed sustained benefit of glucose control. A number of studies have shown the benefit of inpatient control of blood glucose. We await the results of ongoing blood pressure trials and other ongoing trials, which should provide much new information. A conceptual model of cardiovascular risk for people with diabetes mellitus based on the UK Prospective Diabetes Study outcomes model is discussed. SUMMARY: The majority of adults with diabetes have a substantially greater risk compared with those without diabetes and a small percentage has very high risk. A minority of individuals may have considerably lower 10-year risk.     

Dietary cholesterol and atherosclerosis

The perceived relationship between dietary cholesterol, plasma cholesterol and atherosclerosis is based on three lines of evidence: animal feeding studies, epidemiological surveys, and clinical trials. Over the past quarter century studies investigating the relationship between dietary cholesterol and atherosclerosis have raised questions regarding the contribution of dietary cholesterol to heart disease risk and the validity of dietary cholesterol restrictions based on these lines of evidence. Animal feeding studies have shown that for most species large doses of cholesterol are necessary to induce hypercholesterolemia and atherosclerosis, while for other species even small cholesterol intakes induce hypercholesterolemia. The species-to-species variability in the plasma cholesterol response to dietary cholesterol, and the distinctly different plasma lipoprotein profiles of most animal models make extrapolation of the data from animal feeding studies to human health extremely complicated and difficult to interpret. Epidemiological surveys often report positive relationships between cholesterol intakes and cardiovascular disease based on simple regression analyses; however, when multiple regression analyses account for the colinearity of dietary cholesterol and saturated fat calories, there is a null relationship between dietary cholesterol and coronary heart disease morbidity and mortality. An additional complication of epidemiological survey data is that dietary patterns high in animal products are often low in grains, fruits and vegetables which can contribute to increased risk of atherosclerosis. Clinical feeding studies show that a 100 mg/day change in dietary cholesterol will on average change the plasma total cholesterol level by 2.2-2.5 mg/dl, with a 1.9 mg/dl change in low density lipoprotein (LDL) cholesterol and a 0.4 mg/dl change in high density lipoprotein (HDL) cholesterol. Data indicate that dietary cholesterol has little effect on the plasma LDL:HDL ratio. Analysis of the available epidemiological and clinical data indicates that for the general population, dietary cholesterol makes no significant contribution to atherosclerosis and risk of cardiovascular disease.     

Models and assumptions underlying genetic risk assessment

Various methods employed for estimating the genetic risks of radiation are reviewed. With the doubling-dose method, genetic damage is expressed as an increase in cases of known genetic disease. The actual doubling dose is based on figures obtained with the mouse. There have been no recent data on induced mutation frequencies. Recent results suggest that the prevalence figure for multifactorial disease may be at least one order of magnitude higher than before. Various assumptions underlying the doubling-dose concept are discussed in the light of recent findings on: (1) spontaneous mutations resulting from insertion elements, and (2) the comparability between spontaneous and induced mutations. The so-called direct method makes use of figures for induction of dominant mutations affecting the skeleton and the lens of the eye in the mouse, and of translocation induction in monkeys. Induction rates are converted to overall rates of induced dominant effects in man by applying certain assumptions. The proportionality between dose and effect is the basis for all genetic risk assessments. The possible significance of data on human lymphocytes indicating a threshold below 4 rad and the induction of repair enzymes by low radiation doses is discussed. The parallelogram approach is based on the principle that estimates can be obtained on the amount of genetic damage that cannot always be assessed directly. Thus mutations in mouse germ cells can be predicted by using mutation frequencies in cultured mammalian cells and O6-ethylguanine adducts. Measurement of haemoglobin mutations in human and mouse erythrocytes, and of HPRT-deficient mutations in lymphocytes of man and mouse should make more precise estimates of mutation frequencies in human germ cells possible. The development of a database on mutations in somatic cells of the mouse, their induction frequencies and molecular nature are considered an important priority. Used in combination with mouse germ-cell mutation frequencies, they should enable more precise risk estimates on the basis of mutations in somatic cells of man.     

Effectiveness of web-based personalised e‑Coaching lifestyle interventions

Introduction

Interventions to reduce the impact of modifiable risk factors, such as hypercholesterolaemia, smoking, and overweight, have the potential to significantly decrease the cardiovascular disease burden. The majority of the global population is unaware of their own risk of developing cardiovascular disease. Parallel to the lack of awareness, a rise in obesity and diabetes is observed. e‑Health tools for lifestyle improvement have shown to be effective in changing unhealthy behaviour. In this study we report on the results of three different trials assessing the effectiveness of MyCLIC, an e‑Coaching lifestyle intervention tool.

Methods

From 2008 to 2016 we conducted three trials: 1) HAPPY NL: a prospective cohort study in the Netherlands, 2) HAPPY AZM: a prospective cohort study with employees of Maastricht UMC+ and 3) HAPPY LONDON: a single-centre, randomised controlled trial with asymptomatic individuals who have a high 10-year CVD risk.

Results

HAPPY NL and HAPPY AZM showed that e‑Coaching reduced cardiovascular risk. Both prospective trials showed a 20–25% relative reduction in 10-year cardiovascular disease risk. A lesser effect was seen in the HAPPY LONDON trial. A low frequency of logins suggests a low degree of content engagement in the e‑Coaching group, which could be age related as the mean age of the participants in the HAPPY LONDON study was high.

Conclusion

e-Coaching using MyCLIC is a low cost and effective method to perform lifestyle interventions and has the potential to reduce the 10-year cardiovascular disease risk.

     

Studies on familial hypotransferrinemia: unique clinical course and molecular pathology.

Some unsolved problems--late onset of anemia and growth retardation (at age 7 years), healthy siblings showing very low transferrin (TF) level, and unexplained mode of inheritance--were found in family members of a congenital atransferrinemia already reported in 1972. The long-term clinical, laboratory, and developmental observations revealed that after 5 years of apo-TF supplementary therapy the patient's anemia gradually disappeared, and he started to grow again without further therapy. Immunoelectrophoretic study disclosed a severe deficiency of both TF and haptoglobin in the patient. The recovery from his anemia and the resumption of his physical development were dependent only on his TF level: that is, from a negligible level it increased to 10-20 mg/dl (normal, 205-370 mg/dl), a level similar to that of his TF-deficient siblings, who had been in good health since birth. The TF analysis of the patient and his family suggests that the minimum TF requisite in this family may be close to 10-20 mg/dl; subjects with more than 20 mg/dl are apparently healthy; with less than 10 mg/dl they may develop severe growth retardation and anemia, and extreme deficiency may be lethal. Also, coexisting haptoglobin deficiency might alleviate hemosiderosis. Further, the isoelectric focusing study disclosed that there was only a small amount of TF variant in these siblings including the patient. The study of the family confirmed that this variant was produced by an allelic gene derived from their father. So, the original diagnosis of congenital atransferrinemia should be revised as familial hypotransferrinemia transmitted with autosomal recessive mode, and the subjects with a recessive character may be compound heterozygotes of the "variant" allele and the "null" allele.     

Management of Mild-to-Moderate Hypertriglyceridemia

ObjectiveHypertriglyceridemia (HTG) is highly prevalent globally, and its prevalence is rising, with a worldwide increase in the incidence of obesity and diabetes. This review examines its current management and future therapies.MethodsFor this review, HTG is defined as mild-to-moderate elevation in the levels of triglyceride (TG): a fasting or nonfasting TG level of ≥150 mg/dL and <500 mg/dL. We reviewed scientific studies published over the last 30 years and current professional society recommendations regarding the evaluation and treatment of HTG.ResultsGenetics, lifestyle, and other environmental factors impact TG levels. In adults with mild-to-moderate HTG, clinicians should routinely assess and treat secondary treatable causes (diet, physical activity, obesity, metabolic syndrome, and reduction or cessation of medications that elevate TG levels). Because atherosclerotic cardiovascular disease risk is the primary clinical concern, statins are usually the first-line treatment. Patients with TG levels between ≥150 mg/dL and <500 mg/dL whose low-density lipoprotein cholesterol is treated adequately with statins (at “maximally tolerated“ doses, per some statements) and have either prior cardiovascular disease or diabetes mellitus along with at least 2 additional cardiovascular disease risk factors should be considered for added icosapent ethyl treatment to further reduce their cardiovascular disease risk. Fibrates, niacin, and other approved agents or agents under development are also reviewed in detail.ConclusionThe treatment paradigm for mild-to-moderate HTG is changing on the basis of data from recent clinical trials. Recent trials suggest that the addition of icosapent ethyl to background statin therapy may further reduce atherosclerotic cardiovascular disease risk in patients with moderate HTG, although a particular TG goal has not been identified.     

Clinical significance of apolipoprotein A5

PURPOSE OF REVIEW: We have examined the evidence from recent human studies examining the role of apolipoprotein A-V in triglyceride-rich lipoprotein metabolism and cardiovascular disease risk. Special emphasis was placed on the evidence emerging from the association between genetic variability at the apolipoprotein A5 locus, lipid phenotypes and disease outcomes. Moreover, we address recent reports evaluating apolipoprotein A5 gene-environment interactions in relation to cardiovascular disease and its common risk factors. RECENT FINDINGS: Several genetic association studies have continued to strengthen the position of APOA5 as a major gene that is involved in triglyceride metabolism and modulated by dietary factors and pharmacological therapies. Moreover, genetic variants at this locus have been significantly associated with both coronary disease and stroke risks. SUMMARY: Apolipoprotein A-V has an important role in lipid metabolism, specifically for triglyceride-rich lipoproteins. However, its mechanism of action is still poorly understood. Clinical significance at present comes largely from genetic studies showing a consistent association with plasma triglyceride concentrations. Moreover, the effects of common genetic variants on triglyceride concentrations and disease risk are further modulated by other factors such as diet, pharmacological interventions and BMI. Therefore, these genetic variants could be potentially used to predict cardiovascular disease risk and individualize therapeutic options to decrease cardiovascular disease risk.     

Lipoprotein(a) levels and long-term cardiovascular risk in the contemporary era of statin therapy

Lipoprotein(a) [Lp(a)] has enhanced atherothrombotic properties. The ability of Lp(a) levels to predict adverse cardiovascular outcomes in patients undergoing coronary angiography has not been examined. The relationship between serum Lp(a) levels and both the extent of angiographic disease and 3-year incidence of major adverse cardiovascular events (MACE: death, myocardial infarction, stroke, and coronary revascularization) was investigated in 2,769 patients who underwent coronary angiography [median Lp(a) 16.4 mg/dl, elevated levels (≥30 mg/dl) in 38%]. An elevated Lp(a) was associated with a 2.3-fold [95% confidence interval (CI), 1.7–3.2, P < 0.001] greater likelihood of having a significant angiographic stenosis and 1.5-fold (95 CI, 1.3–1.7, P < 0.001) greater chance of three-vessel disease. Lp(a)≥30 mg/dl was associated with a greater rate of MACE (41.8 vs. 35.8%, P = 0.005), primarily due to a greater need for coronary revascularization (30.9 vs. 26.0%, P = 0.02). A relationship between Lp(a) levels and cardiovascular outcome was observed in patients with an LDL cholesterol (LDL-C) ≥70-100 mg/dl (P = 0.049) and >100 mg/dl (P = 0.02), but not <70 mg/dl (P = 0.77). Polymorphisms of Lp(a) were also associated with both plasma Lp(a) levels and coronary stenosis, but not a greater rate of MACE. Lp(a) levels correlate with the extent of obstructive disease and predict the need for coronary revascularization in subjects with suboptimal LDL-C control. This supports the need to intensify lipid management in patients with elevated Lp(a) levels.     

Menopausal Hormone Therapy and Chronic Disease Risk in the Women’S Health Initiative: is Timing Everything?

ObjectiveThis review provides a comprehensive overview of the most recent findings from the Women’s Health Initiative (WHI) hormone therapy (HT) trials and highlights the role of age and other clinical risk factors in risk stratification.MethodsWe review the findings on cardiovascular disease, cancer outcomes, all-cause mortality, and other major endpoints in the two WHI HT trials (conjugated equine estrogens [CEEs, 0.625 mg/day] with or without medroxyprogesterone acetate [MPA, 2.5 mg/day]).ResultsThe hazard ratio (HR) for coronary heart disease (CHD) was 1.18 (95% confidence interval [CI], 0.95 to 1.45) in the CEE + MPA trial and 0.94 (95% CI, 0.78 to 1.14) in the CEE-alone trial. In both HT trials, there was an increased risk of stroke and deep vein thrombosis and a lower risk of hip fractures and diabetes. The HT regimens had divergent effects on breast cancer. CEE + MPA increased breast cancer risk (cumulative HR, 1.28; 95% CI, 1.11 to 1.48), whereas CEE alone had a protective effect (cumulative HR, 0.79; 95% CI, 0.65 to 0.97). The absolute risks of HT were low in younger women (ages 50 to 59 years) and those who were within 10 years of menopause onset. Furthermore, for CHD, the risks were elevated for women with metabolic syndrome or high low-densitylipoprotein cholesterol concentrations but not in women without these risk factors. Factor V Leiden genotype was associated with elevated risk of venous thromboembolism on HT.ConclusionHT has a complex pattern of benefits and risks. Women in early menopause have low absolute risks of chronic disease outcomes on HT. Use of HT for management of menopausal symptoms remains appropriate, and risk stratification will help to identify women in whom benefits would be expected to outweigh risks. (Endocr Pract. 2014;20:1201-1213)     

A Model of Cardiovascular Disease Giving a Plausible Mechanism for the Effect of Fractionated Low-Dose Ionizing Radiation Exposure

Atherosclerosis is the main cause of coronary heart disease and stroke, the two major causes of death in developed society. There is emerging evidence of excess risk of cardiovascular disease at low radiation doses in various occupationally exposed groups receiving small daily radiation doses. Assuming that they are causal, the mechanisms for effects of chronic fractionated radiation exposures on cardiovascular disease are unclear. We outline a spatial reaction-diffusion model for atherosclerosis and perform stability analysis, based wherever possible on human data. We show that a predicted consequence of multiple small radiation doses is to cause mean chemo-attractant (MCP-1) concentration to increase linearly with cumulative dose. The main driver for the increase in MCP-1 is monocyte death, and consequent reduction in MCP-1 degradation. The radiation-induced risks predicted by the model are quantitatively consistent with those observed in a number of occupationally-exposed groups. The changes in equilibrium MCP-1 concentrations with low density lipoprotein cholesterol concentration are also consistent with experimental and epidemiologic data. This proposed mechanism would be experimentally testable. If true, it also has substantive implications for radiological protection, which at present does not take cardiovascular disease into account. The Japanese A-bomb survivor data implies that cardiovascular disease and cancer mortality contribute similarly to radiogenic risk. The major uncertainty in assessing the low-dose risk of cardiovascular disease is the shape of the dose response relationship, which is unclear in the Japanese data. The analysis of the present paper suggests that linear extrapolation would be appropriate for this endpoint.