Atherosclerosis risk factors

Current concepts in coronary artery revascularisation

Coronary artery revascularisation can be performed surgically or percutaneously. Surgery is associated with higher procedural risk and longer recovery than percutaneous interventions, but with long-term reduction of recurrent cardiac events. For many patients with obstructive coronary artery disease in need of revascularisation, surgical or percutaneous intervention is indicated on the basis of clinical and anatomical reasons or personal preferences. Medical therapy is a crucial accompaniment to coronary revascularisation, and data suggest that, in some subsets of patients, medical therapy alone might achieve similar results to coronary revascularisation. Most revascularisation data are based on prevalently White, non-elderly, male populations in high-income countries; robust data in women, older adults, and racial and other minorities, and from low-income and middle-income countries, are urgently needed.

ACAT-1 gene rs1044925 SNP and its relation with different clinical forms of chronic Chagas disease

Chagas disease, caused by the protozoan Trypanosoma cruzi (T. cruzi), although discovered more than a century ago, is still a not very well-elucidated aspect. Individuals in the chronic phase of the disease may present asymptomatic clinical form or symptomatologies related to the cardiac, digestive systems, or both (mixed clinical form). SNPs (single nucleotide polymorphisms) have been identified as important markers because they constitute about 90% of the variation in the human genome. One of them is localized to the ACAT-1 gene (cholesterol acyltransferase 1) (rs1044925) and has been linked to lipid disorders. Some studies have suggested the interaction between T. cruzi and the lipid metabolism of the host. Therefore, the objective of the present study was to evaluate the association between the ACAT-1 gene rs1044925 SNP in relation to clinical manifestations in patients with chronic Chagas disease. A total of 135 individuals with chronic Chagas disease, 86 (63.7%) asymptomatic individuals and 49 (36.3%) symptomatic patients (22 with cardiac clinical form, 18 with digestive form and 9 with mixed form) participated in the study. To evaluate the polymorphism, the PCR-RFLP technique were used. There was a significant difference and a higher frequency of AA and AC genotypes (p = 0.047 and p = 0.016, respectively) of the ACAT-1 gene in asymptomatic chagasic individuals. The result suggests a protective character of the AA and AC genotypes of the rs1044925 SNP in relation to the presence of symptomatic clinical manifestations of the disease in chronic chagasic individuals.

Incentive spirometry for preventing pulmonary complications after coronary artery bypass graft

BACKGROUND

Incentive spirometry (IS) is a treatment technique that uses a mechanical device to reduce pulmonary complications during postoperative care. This is an update of a Cochrane review first published in 2007.

OBJECTIVES

Update the previously published systematic review to compare the effects of IS for preventing postoperative pulmonary complications in adults undergoing coronary artery bypass graft (CABG).

SEARCH METHODS

We searched CENTRAL and DARE on The Cochrane Library (Issue 2 of 4 2011), MEDLINE OVID (1948 to May 2011), EMBASE (1980 to Week 20 2011), LILACS (1982 to July 2011) , the Physiotherapy Evidence Database (PEDro) (1980 to July 2011), Allied & Complementary Medicine (AMED) (1985 to May 2011), CINAHL (1982 to May 2011).

SELECTION CRITERIA

Randomised controlled trials comparing IS with any type of prophylactic physiotherapy for prevention of postoperative pulmonary complications in adults undergoing CABG.

DATA COLLECTION AND ANALYSIS

Two reviewers independently evaluated trial quality using the guidelines of the Cochrane Handbook for Systematic Reviews and extracted data from included trials. For continuous outcomes, we used the generic inverse variance method for meta-analysis and for dichotomous data we used the Peto Odds Ratio.

MAIN RESULTS

This update included 592 participants from seven studies (two new and one that had been excluded in the previous review in 2007. There was no evidence of a difference between groups in the incidence of any pulmonary complications and functional capacity between treatment with IS and treatment with physical therapy, positive pressure breathing techniques (including continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) and intermittent positive pressure breathing (IPPB), active cycle of breathing techniques (ACBT) or preoperative patient education. Patients treated with IS had worse pulmonary function and arterial oxygenation compared with positive pressure breathing. Based on these studies there was no improvement in the muscle strength between groups who received IS demonstrated by maximal inspiratory pressure and maximal expiratory pressure .

AUTHORS' CONCLUSIONS

Our update review suggests there is no evidence of benefit from IS in reducing pulmonary complications and in decreasing the negative effects on pulmonary function in patients undergoing CABG. In view of the modest number of patients studied, methodological shortcomings and poor reporting of the included trials, these results should still be interpreted cautiously. An appropriately powered trial of high methodological rigour is needed to determine if there are patients who may derive benefit from IS following CABG.

Hypolipidaemic and antiplatelet activity of phenoxyacetic acid derivatives related to α-asarone

The phenoxyacetic acid derivatives 1–6 [2-methoxy-4-(2-propenyl)phenoxyacetic acid (1); 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetic acid (2); methyl 2-methoxy-4-(2-propenyl)phenoxyacetate (3); ethyl 2-methoxy-4-(2-propenyl)phenoxyacetate (4); methyl 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetate (5); ethyl 2-methoxy-5-nitro-4-(2-propenyl)phenoxyacetate (6)] related to α-asarone have been reported previously as hypolipidaemic agents in diet-induced hyperlipidaemic mice. We have aimed to expand the pharmacological profile of these derivatives by investigating their hypolipidaemic activity in rats and mice under different experimental conditions. The antiplatelet activity was tested also in-vitro from blood derived from consenting healthy volunteers. In normolipidaemic rats, compounds 2, 3 and 5 at oral doses of 40 and 80 mg kg−1 significantly decreased total cholesterol and LDL-cholesterol levels. Moreover, analogues 3 and 5 administered to hypercholesterolaemic rats at the same doses for seven days also produced a reduction in the content of these same lipoproteins. In neither case were the high-density lipoprotein cholesterol and triglyceride concentrations affected. However, practically all tested compounds were found to be hypocholesterolaemic agents, and were shown to effectively lower low-density lipoprotein cholesterol and triglyceride levels in Triton-induced hyperlipidaemic mice at oral doses of 50 and 100 mg kg−1. In all tests, all animals appeared to be healthy throughout the experimental period in their therapeutic ranges. Triton-induced hypercholesterolaemic mice appeared to be a desirable model for this class of hypolipidaemic drugs. On the other hand, compounds 1, 2, 4 and 5 significantly inhibited ADP-induced aggregation in-vitro. These findings indicated that all of these compounds appeared to be promising for the treatment of human hyperlipidaemia and thrombotic diseases.

Hypertension, hypercholesterolemia, diabetes, and risk of Parkinson disease

OBJECTIVE

To determine whether history of hypertension, hypercholesterolemia, or diabetes is associated with risk of Parkinson disease (PD).

METHODS

Prospective study among participants in two large cohorts: the Nurses' Health Study (121,046 women) and the Health Professionals Follow-up Study (50,833 men). Mean duration of follow-up was 22.9 years in women, aged 30 to 55 years at baseline, and 12.6 years in men, aged 40 to 75 years at baseline. Relative risks (RRs) of PD were estimated from a Cox proportional hazards model adjusting for potential confounders.

RESULTS

We identified a total of 530 incident cases of PD during the follow-up. Risk of PD was not associated with self-reported history of hypertension (RR = 0.96, 95% CI = 0.80 to 1.15), high cholesterol (RR = 0.98, 95% CI = 0.82 to 1.19), or diabetes (RR = 1.04, 95% CI = 0.74 to 1.46), after adjusting for age and smoking in pack-years. Risk of PD decreased modestly with increasing levels of self-reported total cholesterol (RR for a 50-mg/dL increase in total cholesterol = 0.86, 95% CI = 0.78 to 0.95, p for trend = 0.02), but use of cholesterol-lowering drugs was not associated with PD risk (RR comparing users with nonusers = 0.85, 95% CI = 0.59 to 1.23). Among individuals with PD, systolic blood pressure was similar to noncases up to the time of diagnosis but declined afterward.

CONCLUSIONS

Results of this large prospective study suggest that Parkinson disease risk is not significantly related to history of hypertension, hypercholesterolemia, or diabetes but may modestly decline with increasing blood cholesterol levels.

Incentive spirometry for preventing pulmonary complications after coronary artery bypass graft

BACKGROUND

Following coronary artery bypass graft (CABG), the main causes of postoperative morbidity and mortality are postoperative pulmonary complications, respiratory dysfunction and arterial hypoxemia. Incentive spirometry is a treatment technique that uses a mechanical device (an incentive spirometer) to reduce such pulmonary complications during postoperative care.

OBJECTIVES

To assess the effects of incentive spirometry for preventing postoperative pulmonary complications in adults undergoing CABG.

SEARCH STRATEGY

We searched CENTRAL on The Cochrane Library (Issue 2, 2004), MEDLINE (1966 to December 2004), EMBASE (1980 to December 2004), LILACS (1982 to December 2004), the Physiotherapy Evidence Database (PEDro) (1980 to December 2004), Allied & Complementary Medicine (AMED) (1985 to December 2004), CINAHL (1982 to December 2004), and the Database of Abstracts of Reviews of Effects (DARE) (1994 to December 2004). References were checked and authors contacted. No language restrictions were applied.

SELECTION CRITERIA

Randomized controlled trials comparing incentive spirometry with any type of prophylactic physiotherapy for prevention of postoperative pulmonary complications in adults undergoing CABG.

DATA COLLECTION AND ANALYSIS

Two reviewers independently evaluated the quality of trials using the guidelines of the Cochrane Reviewers' Handbook and extracted data from included trials.

MAIN RESULTS

Four trials with 443 participants contributed to this review. There was no significant difference in pulmonary complications (atelectasis and pneumonia) between treatment with incentive spirometry and treatment with positive pressure breathing techniques (continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP) and intermittent positive pressure breathing (IPPB)) or preoperative patient education. Patients treated with incentive spirometry had worse pulmonary function and arterial oxygenation compared with positive pressure breathing (CPAP, BiPAP, IPPB).

AUTHORS' CONCLUSIONS

Individual small trials suggest that there is no evidence of benefit from incentive spirometry in reducing pulmonary complications and in decreasing the negative effects on pulmonary function in patients undergoing CABG. In view of the modest number of patients studied, methodological shortcomings and poor reporting of the included trials, these results should be interpreted cautiously. An appropriately powered trial of high methodological rigour is needed to determine those patients who may derive benefit from incentive spirometry following CABG.

Coronary risk factors in adult children of parents with coronary heart disease: a comparison survey of southeastern Brazil and southeastern United States

A survey was performed in southeastern Brazil and in the southeastern United States to: 1) compare coronary risk factors in adult children (>18 years old) of parents with coronary heart disease enrolled in cardiac rehabilitation programs in countries with different geographic, social, and economic factors; and 2) to assess the influence of coronary heart disease of parents on alteration of lifestyle in these adult children. There were 286 biological children available for the survey (135 Brazil, 151 United States). Of those, 142 completed the survey (78 Brazil, 64 United States) for an overall compliance rate of 50% (58% Brazil, 42% United States). The following differences were noted: blood pressure > 159/90 mm Hg (23% Brazil, 15% United States [nonsignificant]); total cholesterol > 181 mg/dL (5% Brazil, 30% United States [p < 0.001]); HDL-C < 35 mg/dL (95% Brazil, 21% United States [p < 0.001]); low-fat diet (29% Brazil, 64% United States [p < 0.001]); smoke/ever (41% Brazil, 34% United States [nonsignificant]); currently smoke (72% Brazil, 18% United States [p < 0.001]); any exercise [44% Brazil, 82% United States [p < 0.001]); exercise > 90 minute/week (18% Brazil, 20% United States [nonsignificant]); improved lifestyle habits (39% Brazil, 79% United States [p < 0.001]); improved lifestyle habits related to parent's coronary heart disease (66% Brazil, 35% United States [p < 0.05]). Such differences may reflect geographic, social, and/or economic factors.

Concept and usefulness of cardiovascular risk profiles

Despite major advances in the diagnosis and treatment of atherosclerotic cardiovascular disease (CVD) in the past century, it remains a serious clinical and public health problem. Multivariable risk factor analysis is now commonly performed to identify high-risk candidates for CVD who need preventive measures and to seek out clues to the pathogenesis of the disease. The set of risk factors used for the former is constrained by practical considerations, and the set of risk factors used for the latter is constrained by the hypothesis being tested. This report reviews the evolution and usefulness of multivariable risk functions crafted for estimating risk of clinical manifestations of atherosclerosis and for gaining insights into their pathogenesis. Decades of evaluation of CVD risk factors by the Framingham Study led to the conclusion that CVD risk evaluation is most fruitfully appraised from the multivariable risk posed by a set of established risk factors. Such assessment is essential because risk factors seldom occur in isolation, and the risk associated with each varies widely depending on the burden of associated risk factors. About half the CVD in the general population arises from the segment with multiple marginal risk factor abnormalities. Although disease-specific profiles are available, a multivariable risk formulation for coronary disease comprised of age, sex, the total/high-density lipoprotein cholesterol ratio, systolic blood pressure, glucose intolerance, cigarette smoking, and electrocardiography-left ventricular hypertrophy is also predictive of peripheral artery disease, heart failure, and stroke because of shared risk factors. Correcting risk factors for any particular CVD has the potential to protect against > or =1 of the others. Multivariable risk stratification is now recognized as essential in efficiently identifying likely candidates for CVD and quantifying the hazard.

A Chlamydia pneumoniae component that induces macrophage foam cell formation is chlamydial lipopolysaccharide

Chlamydia pneumoniae infection is associated with atherosclerotic heart and vessel disease, but a causal relationship between this pathogen and the disease process has not been established. Recently, it was reported that C. pneumoniae induces human macrophage foam cell formation, a key event in early atheroma development, suggesting a role for the organism in atherogenesis. This study further examines C. pneumoniae-induced foam cell formation in the murine macrophage cell line RAW-264.7. Infected RAW cells accumulated cholesteryl esters when cultured in the presence of low-density lipoprotein in a manner similar to that described for human macrophages. Exposure of C. pneumoniae elementary bodies to periodate, but not elevated temperatures, inhibited cholesteryl ester accumulation, suggesting a role for chlamydial lipopolysaccharide (cLPS) in macrophage foam cell formation. Purified cLPS was found to be sufficient to induce cholesteryl ester accumulation and foam cell formation. Furthermore, the LPS antagonist lipid X inhibited C. pneumoniae and cLPS-induced lipid uptake. These data indicate that cLPS is a C. pneumoniae component that induces macrophage foam cell formation and suggest that infected macrophages chronically exposed to cLPS may accumulate excess cholesterol to contribute to atheroma development.

Changes in risk factors and the decline in mortality from cardiovascular disease. The Framingham Heart Study

A decline in mortality from cardiovascular disease over the past 30 years has been well documented, but the reasons for the decline remain unclear. We analyzed the 10-year incidence of cardiovascular disease and death from cardiovascular disease in three groups of men who were 50 to 59 years old at base line in 1950, 1960, and 1970 (the 1950, 1960, and 1970 cohorts) in order to determine the contribution of secular trends in the incidence of cardiovascular disease, risk factors, and medical care to the decline in mortality. The 10-year cumulative mortality from cardiovascular disease in the 1970 cohort was 43 percent less than that in the 1950 cohort and 37 percent less than that in the 1960 cohort (P = 0.04 by log-rank test). Among the men who were free of cardiovascular disease at base line, the 10-year cumulative incidence of cardiovascular disease declined approximately 19 percent, from 190 per 1000 in the 1950 cohort to 154 per 1000 in the 1970 cohort (0.10 less than P less than 0.20 by chi-square test), whereas the 10-year rate of death from cardiovascular disease declined 60 percent (relative risk for the 1950 cohort as compared with the 1970 cohort, 2.53; 95 percent confidence interval, 1.22 to 5.97). Significant improvements were found in risk factors for cardiovascular disease among the men initially free of cardiovascular disease in the 1970 cohort as compared with those in the 1950 cohort, including a lower serum cholesterol level (mean +/- SD, 5.72 +/- 0.98 mmol per liter [221 +/- 38 mg per deciliter], as compared with 5.90 +/- 1.03 mmol per liter [228 +/- 40 mg per deciliter]) and a lower systolic blood pressure (mean +/- SD, 135 +/- 19 mm Hg, as compared with 139 +/- 25 mm Hg), better management of hypertension (22 percent vs. 0 percent were receiving antihypertensive medication), and reduced cigarette smoking (34 percent vs. 56 percent). We propose that these improvements may have had more pronounced effects on mortality from cardiovascular disease than on the incidence of cardiovascular disease in this population. Our data suggest that the improvement in cardiovascular risk factors in the 1970 cohort may have been an important contributor to the 60 percent decline in mortality in that group as compared with the 1950 cohort, although a decline in the incidence of cardiovascular disease and improved medical interventions may also have contributed to the decline in mortality.

Hypolipidemic activity of cyclic imido alkyl ethers, thioethers, sulfoxides, and sulfones

N-Substituted alkyl ethers, thioethers, sulfoxides, and sulfones of cyclic imides (e.g., phthalimide, saccharin, 1,8-naphthalimide, succinimide, and 2,3-dihydrophthalazine-1,4-dione) were shown to have potent hypolipidemic activity at doses of 10 and 20 mg/kg/d in rodents. These N-substitutions afforded no improvement over other known N-substitutions (e.g., butyl, 3-butanone, or the propionic acid derivatives of phthalimide, saccharin, and 2,3-dihydrophthalazine-1,4-dione) compared with the respective parent compounds. However, 2-(methoxyethyl)-1H-benz[de]isoquinoline-1,3-(2H)dione (3a), 2-[2-methylsulfinyl]ethyl-1H-benz[de]isoquinoline-1,3-(2H)dione (3c), 1-(2-methylsulfinyl)-2,5-pyrrolidenedione (4c), and 1-(2-methoxyethyl-2,5-pyrrolidenedione (4a) significantly improved activity compared with parent compounds, as well as previously reported N-substituted analogues, reducing serum cholesterol levels and serum triglyceride levels by 40%. The thioether of succinimide afforded a 54% reduction of serum cholesterol and a 41% reduction of serum triglyceride levels in mice after 16 d. The alkyl thioethers of 1,8-naphthalimide and succinimide significantly lowered cholesterol levels in serum VLDL and LDL, while the alkyl thioethers of succinimide elevated HDL cholesterol content. Tissue lipids were reduced in the liver and aorta by these selected derivatives. The activities of regulatory enzymes in de novo synthesis of hepatic cholesterol and triglyceride were inhibited by the selected 1,8-naphthalimide derivatives. In situ cholesterol and cholic acid reabsorption from intestines were suppressed by the presence of the agents.

Effects of antihypertensive therapy on cardiac function

The failure of clinical trials in the treatment of hypertension to show protection against mortality from coronary heart disease has prompted a major reconsideration of the indications and modes of therapy. One area of concern is the lipid disturbances seen with diuretics and non-ISA (intrinsic sympathomimetic activity) beta blockers; another is the negative inotropic effect of beta blockers. The more widespread use of vasodilators--either alpha-blockers, angiotensin-converting enzyme (ACE) inhibitors, or calcium channel blockers--therefore seems appropriate. Among the calcium channel blockers, nicardipine appears to be a particularly attractive choice, in part because of its lack of negative inotropism.

The effects of phthalimide and saccharin derivatives on low-density lipoprotein (LDL) and high-density lipoprotein (HDL) receptor activity and related enzyme activities

The hypolipidemic agents, phthalimide, saccharin, o-(N-phthalimido) acetophenone, N-(p-chlorobenzoyl) sulfamate, and o-chlorobenzylsulfonamide affected low-density lipoprotein (LDL) and high-density lipoprotein (HDL) receptor activity and lipoprotein degradation. In isolated rat hepatocytes, rat aorta foam cells, and human fibroblasts, LDL receptor activity, which is dependent on apo-B and -E, was inhibited by the drugs in a dose-dependent manner. LDL degradation was accelerated in the hepatocytes, while it was inhibited in aorta cells and fibroblasts. The drugs enhanced HDL receptor activity, dependent on apo-E and -A1, and HDL degradation in the hepatocytes, whereas in fibroblasts and aorta cells HDL receptor binding and degradation were suppressed. In parallel, activities of acyl CoA acyl transferase, sn-glycerol-3-phosphate acyl transferase, and heparin-induced lipoprotein lipase decreased and activities of HMG-CoA reductase and cholesterol oleate-ester hydrolase increased. In fibroblasts the presence of drugs enhanced HDL binding of intracellular cholesterol. In vivo studies demonstrated that phthalimide and saccharin treatment enhanced the clearance of HDL and decreased the clearance of LDL from the serum of rats. The results suggest that the mode of action of the agents is to modulate the lipoprotein receptor and, thereby, the clearance of lipids from peripheral tissue as part of the hypolipidemic activity.