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

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.

Perspectives in the treatment of dyslipidemias in the prevention of coronary heart disease

In this review the indications for the available treatments for dyslipidemias in the prevention of coronary heart disease (CHD) are considered, and their efficacy according to the latest studies is analyzed. As data sources the authors used the main multicenter studies performed in the last twenty years to evaluate primary and secondary prevention of CHD by correcting dyslipidemias as well as the results of meta-analyses of these studies. All treatments considered were found effective in preventing CHD morbidity and mortality to some extent. In particular, the combination of diet with niacin or hydroxymethylglutaryl coenzyme A (HMG CoA) reductase inhibitors seems to give the best results. These drugs induce a marked reduction of total and low-density lipoprotein (LDL) cholesterol and an increase of high-density lipoprotein (HDL) cholesterol concentrations. The use of diet, niacin, and HMG CoA reductase inhibitors reduces total as well as specific mortality. Treatment of dyslipidemia to prevent CHD depends on the pattern and severity of dyslipidemia, the presence of overt CHD, and the patient's response to diet. Pharmacologic treatment should be started only after dietary modifications have been tried and must be combined with diet. Drug side effects must also be considered, for they may affect patient compliance. High levels of total and LDL and low levels of HDL cholesterol are major risk factors for coronary atherosclerosis. Correcting lipid abnormalities can reduce the risk of development or progression of CHD. Diet and drugs are the main instruments available to normalize lipid levels. The choice of drug to combine with diet must be based on its specific effects on lipid metabolism, side effects, and efficacy in reducing CHD.

Effects of nonpharmacologic therapy with cardiac rehabilitation and exercise training in patients with low levels of high-density lipoprotein cholesterol

In a study of 591 consecutive coronary patients, we identified 243 (41%) with low high-density lipoprotein (HDL) cholesterol <35 mg/dl and demonstrated the benefits of vigorous nonpharmacologic therapy with cardiac rehabilitation and exercise training in this subgroup. However, patients with low HDL and "normal" triglycerides have significantly greater improvements in low-density lipoprotein (LDL) cholesterol and LDL/HDL ratio than patients with low HDL cholesterol and hypertriglyceridemia who are more likely to require drug treatment.

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.

Effects of cardiac rehabilitation and exercise training on low-density lipoprotein cholesterol in patients with hypertriglyceridemia and coronary artery disease

Substantial data suggest that elevated triglycerides are associated with increased coronary risk, and may be an independent coronary risk factor. Although it is generally accepted that patients with hypertriglyceridemia can have marked improvement in lipids after vigorous nonpharmacologic therapy, data to support this belief are lacking. This study assessed 313 consecutive patients before and after outpatient phase II cardiac rehabilitation and exercise programs to compare the response of patients with elevated triglycerides (> or = 250 mg/dl; n = 39) to vigorous nonpharmacologic therapy with the response of patients with "normal" triglyceride levels (< 150 mg/dl; n = 157). The independent effects that baseline triglycerides, as well as other variables, had on improving lipids after nonpharmacologic therapy were also determined. After cardiac rehabilitation and exercise training, patients had improvement in total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol levels, low-density lipoprotein (LDL) cholesterol levels, LDL/HDL ratios, body mass index, percent body fat, and METs. Patients with hypertriglyceridemia were younger (p = 0.05) and had higher baseline body mass index (p < 0.001) and LDL/HDL ratios (p < 0.0001) but lower HDL cholesterol levels (p < 0.0001) than patients with low baseline triglycerides. Both groups had improvement in lipids, obesity indexes, and exercise capacity. However, patients with hypertriglyceridemia had significantly greater reductions in triglycerides (-31% vs +3%; p < 0.0001), but had less improvement in both LDL cholesterol levels (0% vs -4%; p < 0.01) and LDL/HDL ratios (-5% vs -9%; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Low-dose, time-release nicotinic acid: effects in selected patients with low concentrations of high-density lipoprotein cholesterol

In a retrospective analysis, 63 participants in a cardiac rehabilitation-preventive cardiology program were identified as having low blood concentrations (mean, 34 mg/dl) of high-density lipoprotein cholesterol (HDL-C) and a mean total cholesterol level of 223 mg/dl after 3 months of hygienic measures (aerobic exercise, avoidance of tobacco, diet, and weight loss) designed to increase the HDL-C level. These patients (treatment group) were treated with low-dose, time-release nicotinic acid (mean, 1,297 mg/day) for a mean duration of 7.4 months. All subjects were able to take the drug without intolerable side effects. Fifty-four patients similar to those in the treatment group participated in the same program but were not treated with nicotinic acid (control group). Exercise, diet, body weight, and smoking remained stable throughout the period of observation. For the treatment group, HDL-C levels increased a mean of 18% (+6 mg/dl), total cholesterol concentrations decreased 9% (-20 mg/dl), the ratio of total cholesterol to HDL-C decreased 25% (from 6.8 to 5.1), low-density lipoprotein cholesterol levels decreased 13% (-20 mg/dl), and triglyceride levels decreased 20% (from 165 mg/dl to 132 mg/dl). Aspartate aminotransferase and uric acid concentrations were minimally increased after treatment, and the blood glucose level was unchanged. In the control group, HDL-C levels increased a mean of 8% (+3 mg/dl) and the other blood lipid variables were not improved after a mean of 8.3 additional months of diet and exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug therapy for hyperlipidemia. When reducing cardiovascular risk is a priority

If you are confused about the plethora of lipid-lowering agents now available and have not been able to read all the latest studies, you are not alone. It is almost impossible for busy physicians to keep up with this rapidly growing area of research. Drs Bays and Dujovne provide an update of the major antihyperlipidemics, along with a discussion of how to select patients for this therapy and the relative cost-effectiveness of the different types of therapy.

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.

How much testing is needed after myocardial infarction?

Both physicians and patients should be encouraged by the tremendous progress made in the clinical care of patients with heart disease during the last 20 years. However, the number of invasive and noninvasive tests is vast, so they need to be applied judiciously, using a reasonable set of clinical principles to recognize the needs of the individual patient. In the case of myocardial infarction, one of the most important prognostic factors is left ventricular systolic function, which is commonly measured by the ejection fraction. This measurement can be made with a left ventriculogram, radionuclide ventriculogram, or two-dimensional echocardiogram, the choice depending on individual circumstances.

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.

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.