Management of lipids in primary and secondary prevention of cardiovascular diseases

Homozygous familial hypercholesterolemia

Familial hypercholesterolema (FH) is an inherited autosomal dominant disorder of lipid metabolism. We report a 3 years old female child who presented with multiple eruptive xanthomatosis of skin since 6 months of age and had deranged lipid profile consistent with FH.

Thrombophilia in Patients with Hypertriglyceridemia

Objectives: To investigate a possible relationship between hypertriglyceridemia and the coagulation system, a Cardiovascular Risk Factor Two-township Study was conducted in Taiwan. Design: A case-control study. This longitudinal, prospective study focused on the evolution of cardiovascular disease risk factors with emphasis on haemostatic factors. Subjects: Hypertriglyceridemic subjects (triglyceride <2.26 mmoll+1, n = 327) and age-matched normal controls from a population screening program. Main outcome measures: Haemostatic parameters measured in this study included prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, factors VIIc and VIIIc, and antithrombin-III and plasminogen levels. Results: In our male hypertriglyceridemic subjects, aPTT was not significantly reduced, while significant elevations of factor VIIIc, factor VIIc, and plasminogen and antithrombin-III levels were noted. In the female hypertriglyceridemic subjects, the elevation of factor VIIc, factor VIIIc, and plasminogen and antithrombin-III levels was highly-significant, whereas aPTT was not significantly reduced. Unexpectedly, the levels of the established coronary risk factor, fibrinogen, did not show a statistically different change. Similar to previous data, our hypertriglyceridemic subjects also presented with hyperinsulinemia, glucose intolerance, upper body obesity, and elevated blood pressure. Conclusions: Despite the fact that in population studies, triglycerides do not consistently appear to be an independent risk factor for coronary heart disease, our data suggest that a pronounced increase in triglycerides warrants aggressive therapy, because this increase may be associated with a hypercoagulable state. This phenomenon contributes another perspective to the study of higher cardiovascular mortality in hypertriglyceridemic subjects.

Cardiac rehabilitation and preventive cardiology in the elderly

This article reviews data demonstrating the benefits of cardiac rehabilitation and exercise training programs in the elderly. Other risk factor interventions, including cessation of smoking, treatment of diabetes, and lipid therapy, are very beneficial for the elderly with coronary heart disease or strong risk of coronary heart disease. Also briefly reviewed are current data suggesting the benefits of antioxidant vitamins, and folic acid to reduce levels of homocysteine for the primary and secondary prevention of coronary heart disease in the elderly.

Insights into the pathogenesis and prevention of coronary artery disease

OBJECTIVE

To present information about risk factor clustering and the oxidation hypothesis of atherosclerosis and attempt to synthesize these facts into a clinically relevant approach to patients with or at risk for coronary artery disease (CAD).

MATERIAL AND METHODS

The total cholesterol level is a relatively weak marker for the risk of CAD. The levels of both high-density lipoprotein (HDL) cholesterol and remnants of triglyceride-rich lipoproteins and the inherent susceptibility of the low-density lipoprotein (LDL) particles to oxidative modification may be as important as the total or LDL cholesterol levels. LDL cholesterol must undergo oxidative modification by means of oxygen free radical processes before it becomes atherogenic. Patients with high levels of oxidative stress include those with risk factor clustering or insulin resistance (or both). Such patients are characterized by hypertension, truncal obesity, hypertriglyceridemia, depressed HDL cholesterol levels, and increased insulin levels. They also have increased levels of triglyceride-rich remnant lipoproteins and LDL particles that are characterized by their small dense nature and pronounced predisposition to oxidative modification.

RESULTS

Biologic antioxidants seem to be promising therapy for the prevention of atherogenesis. Although long-term prospective data are not yet available, vitamin E has been shown to be effective in both animal and human models in preventing LDL oxidation, and it may have a role in the prevention of CAD. A healthy diet of fresh fruits, vegetables, and whole grains is beneficial because it improves the lipid levels and provides high levels of natural antioxidants. The atherogenic potential of hydrogenated polyunsaturated fats is approximately equivalent to that of saturated fats. Monounsaturated fat is inherently resistant to oxidation and may be protective against CAD. Niacin may be effective in patients with clustered risk factors. It has been found to convert the easily oxidized small dense LDL pattern to the large buoyant oxidation-resistant particles. Hydroxymethylglutaryl-coenzyme A reductase inhibitors are well tolerated and highly effective in decreasing LDL cholesterol, but they are expensive. Estrogen has multiple potentially beneficial effects relative to cardiovascular disease.

CONCLUSION

Persons with or at high risk for CAD should be identified early and aggressively treated with a program that involves lifestyle changes, alterations in dietary intake, and pharmacologic therapy.

A comparison of education methods and their impact on behavioral change in patients with hyperlipidemia

We sought to determine the efficacy of a hospital-based, professionally-taught program emphasizing cardiovascular health. Similar programs are in existence throughout the country without documentation of their long-term benefits. Thirty-six hyperlipidemic individuals were treated as a control group or participated in one of two intensive educational interventions. The educational program was based on information obtained from focus group methodology to elicit attitudes about dietary change and learning style preferences. Behavioral changes in smoking, dietary salt and saturated fat intake, stress and tension, physical activity, and departure from ideal body weight were documented using health questionnaires and Lifestyle Risk Indices. At three months of follow-up, there was no change in serum lipids, total fat intake, or cardiovascular risk behavior in either the control or intervention group. We conclude that a one-day program, whether designed by the target population or experts, did not improve cardiovascular risk behaviors, suggesting that more innovative methods are required to address health behaviors in this high risk group.

Hypolipidemic effect of type Ia antiarrhythmic agents in postinfarction patients

BACKGROUND

Elevated levels of cholesterol and apoprotein B (apo B), the essential carrier protein for low density lipoprotein, are major lipid risk factors for premature coronary disease. Antiarrhythmic agents are frequently prescribed to patients with coronary heart disease and associated cardiac arrhythmias. As part of another study, we retrospectively investigated the effect of antiarrhythmic agents on blood lipids.

METHODS AND RESULTS

The study population consisted of 1,567 postinfarction patients on whom we prospectively collected serial blood samples for lipid and apoprotein determinations and recorded the concomitant medications the patients were receiving at three follow-up time periods. The lipids, analyzed at a central core laboratory, included total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL C), and apoproteins A-I (apo A-I), A-II (apo A-II), and apo B. The difference in the group mean lipid values for patients receiving and not receiving type Ia antiarrhythmic agents (quinidine, procainamide, and disopyramide) was evaluated by the two-sample t test, and multiple linear regression analyses were performed to adjust for relevant covariates. Patients using type Ia antiarrhythmic agents at the 30-month postinfarction contact (n = 76) had 8.6% lower cholesterol (p less than 0.003), 22.3% lower triglycerides (p less than 0.0002), 6.2% lower apo A-I (p = 0.02), 10.1% lower apo A-II (p less than 0.001), and 12.7% lower apo B (p less than 0.0001) levels than patients not on these medications (n = 1,491). These lower lipid levels were found after adjustment for age, sex, diabetes, smoking status, concomitant medications, and a variety of clinical factors relating to the severity of the coronary disease process. The HDL C levels were similar in those receiving and not receiving type Ia agents.

CONCLUSIONS

Patients on type Ia antiarrhythmic agents had significantly and meaningfully lower cholesterol, triglyceride, apo A-II, and apo B levels than patients not receiving these agents. The mechanism of this hypolipidemic effect is undefined, but the mechanism may be related to an alteration by these agents of ionic membrane currents at the hepatocyte level.

Exercise and the heart. Good, benign, or evil?

The risks and benefits of regular aerobic exercise have been studied extensively. Because of the potential risks, we believe that sedentary persons over age 40 who have cardiac risk factors, as well as patients with coronary artery disease (CAD), should have a complete physical examination and probably an exercise electrocardiogram before starting a vigorous exercise program. In general, however, regular exercise has proven to be extra-ordinarily safe and the theoretical and proven benefits appear to greatly outweigh the risks in most people, including those with CAD, those with severe left ventricular dysfunction, and the elderly.

Assessment of stable ischemic heart disease. Which tests are best for which patients?

An understanding of the importance of various risk factors, the pathogenesis of myocardial ischemia, and the appropriate use of various noninvasive and invasive tests is essential for management of patients with known or suspected coronary artery disease (CAD). Although coronary angiography remains the "gold standard" for diagnosis of CAD, much of the data obtained from risk factor assessment, medical history, and various noninvasive tests provides information that may be even more important than cardiac catheterization data alone for defining prognosis and directing management.

Using lipid-lowering agents effectively. When diet is not enough

Lipid-lowering agents can be used safely and effectively if the physician understands the nature of the patient's disorder and the mechanism of action of the various drugs. The benefits of altering lipid levels are manifested over years, not months. Without a long-term plan for periodic follow-up and intervention, short-term gains will accomplish very little.

High-density lipoprotein cholesterol. Recommendations for routine testing and treatment

Evidence from epidemiologic, lipid intervention, and coronary angiographic studies demonstrates the importance of high-density lipoprotein cholesterol (HDL-C) in coronary artery disease (CAD) risk. Data from these studies strongly support the measurement of HDL-C in all patients screened for CAD. Patients with low levels should be treated using nonpharmacologic measures. High-risk patients deserve consideration for specific drug treatment.

Cardiovascular rehabilitation: status, 1990

Cardiovascular rehabilitation is defined as the process of development and maintenance of a desirable level of physical, social, and psychologic functioning after the onset of a cardiovascular illness. Patient education, counseling, nutritional guidance, and exercise training play prominent roles in the process of rehabilitation. Benefits from cardiac rehabilitation include improved exercise capacity and decreased symptoms of angina pectoris, dyspnea, claudication, and fatigue. Recent pooled data regarding exercise training after myocardial infarction demonstrated a 20 to 25% reduction in mortality and major cardiac events. Exercise training may result in an improvement in systemic oxygen transport, a reduction in the myocardial oxygen requirement for a given amount of external work, and a decrease in the extent of myocardial ischemia during physical activity. The efficacy of modification of risk factors in reducing the progression of coronary artery disease and future morbidity and mortality has been established. Herein we review the history, current practice and results, and future challenges of cardiovascular rehabilitation.

Dietary prevention of coronary artery disease. How to help patients modify eating habits and reduce cholesterol

The prevalence of high serum cholesterol levels and the associated epidemic of coronary artery disease in our society are largely the by-products of a maladaptive diet. Dietary modification is the logical and effective approach to this problem for most patients. In general, dietary therapy consists of a reduction in the intake of saturated fatty acids, cholesterol, and excess calories. Many specific dietary modifications, including increased intake of omega-9 and omega-3 fatty acids and soluble fiber, may also help reduce cholesterol levels and prevent coronary artery disease.