Gerald T. Gau

Prevention of cardiovascular disease: Of what value are risk factor modification, exercise, fish consumption, and aspirin therapy?

PreviewAlthough on the decline, cardiovascular disease remains a major present and future threat to health in the United States. Family physicians, internists, and cardiologists face the dual challenge of impeding its progression and preventing its development. Intervention in modifiable risk factors, regular exercise, increased fish consumption, and daily aspirin therapy may each have an important role to play. In this article, Dr Lavie and coauthors discuss in detail the possible benefits of each.

Novel Risk Factors for Atherosclerosis

In the past several years, evidence has accumulated that factors other than conventional risk factors may contribute to the development of atherosclerosis. Conventional risk factors predict less than one half of future cardiovascular events. Furthermore, conventional risk factors may not have the same causal effect in different ethnic groups in whom novel risk factors may have a role. These newer risk factors for atherosclerosis include homocysteine, fibrinogen, impaired fibrinolysis, increased platelet reactivity, hypercoagulability, lipoprotein(a), small dense low-density lipoprotein cholesterol, and inflammatory-infectious markers. Identification of other markers associated with an increased risk of atherosclerotic vascular disease may allow better insight into the pathobiology of atherosclerosis and facilitate the development of preventive and therapeutic measures. In this review, we discuss the evidence associating these factors in the pathogenesis of atherosclerosis, the mechanism of risk, and the clinical implications of this knowledge.

Spectrum of echocardiographic findings in bacterial endocarditis.

Forty-seven echocardiograms were obtained in 32 patients with bacterial endocarditis. Preexistent abnormalities were found in 14 patients. In five of them thought to have bacterial endocarditis on normal valves, echocardiography showed mitral stenosis (one), bicuspid aortic valve (two), and prolapse of mitral valve (two). Definite vegetations were seen in 22 patients--on the aortic valve in seven, the mitral valve in 12, and both valves in three. Ten patients had milder changes suggestive but not diagnostic of vegetations. In 12 patients, surgery confirmed the echocardiographic findings. Fourteen had systemic embolic episodes and all had echocardiographic evidence of vegetations. Abnormalities secondary to bacterial endocarditis, other than vegetations, were common. Twenty-one patients had left ventricular volume overload. Ten had a flail posterior leaflet of the mitral valve, three of which were confirmed surgically. Eight had abnormal coarsely fluttering echoes in the left ventricular outflow tract consistent with a prolapsing aortic valve or underlying aortic vegetations; four were confirmed by surgery. Five had signs of severe aortic regurgitation of recent onset (premature mitral valve closure) and all had confirmation by surgery. Echocardiographic abnormalities persisted after successful medical treatment. We conclude that echocardiography is helpful in patients with bacterial endocarditis. It permits recognition of unsuspected preexistent lesions and the characteristic vegetations, as well as the extent and nature of valvular damage secondary to bacterial endocarditis. However, echocardiography does not differentiate between active and healed lesions.

Prognostic significance of exercise-induced systemic hypertension in healthy subjects

Exercise hypertension has been suggested to predict future resting hypertension, but its significance in terms of cardiovascular risk has not been defined. To assess the prognostic significance of exercise hypertension, 150 healthy, asymptomatic subjects with normal resting blood pressures and exercise systolic blood pressures > or =214 mm Hg (i.e., >90th percentile) on Bruce treadmill tests were identified retrospectively and age- and gender-matched with subjects with exercise systolic blood pressures of 170 to 192 mm Hg (40th to 70th percentiles). Subjects were contacted by survey a mean of 7.7+/-2.9 years after the index treadmill test. The survey response rate was 93%. There were 12 deaths, including 8 in the exercise hypertension group. A major cardiovascular event, defined as cardiovascular death, myocardial infarction, stroke, coronary angioplasty, or coronary bypass graft surgery occurred in 5 controls and 10 subjects with exercise hypertension. At follow-up, 13 controls and 37 subjects with exercise hypertension were now diagnosed as having resting hypertension. In multivariate analysis, exercise hypertension was not a significant predictor for death or any individual cardiovascular event, but was for total cardiovascular events and new resting hypertension. The multivariate risk ratio for exercise hypertension was 3.62 (p = 0.03) in predicting a major cardiovascular event. Other significant predictors included body mass index and age. For predicting new resting hypertension, the multivariate odds ratio for exercise hypertension was 2.41 (p = 0.02). These data suggest that exercise hypertension carries a small but significant risk for major cardiovascular events in healthy, asymptomatic persons with normal resting blood pressures.

Peak exercise blood pressure stratified by age and gender in apparently healthy subjects

OBJECTIVE To determine the peak blood pressure responses during symptom-limited exercise in a large sample of apparently healthy subjects, including both men and women over a wide range of ages. DESIGN We retrospectively studied the blood pressure response during maximal treadmill exercise testing with use of the Bruce protocol in apparently healthy subjects. MATERIAL AND METHODS Peak exercise blood pressures in 7,863 male and 2,406 female apparently healthy subjects who underwent a screening treadmill exercise test with the Bruce protocol between 1988 and 1992 were analyzed by age and gender. RESULTS In this large referral population of apparently healthy subjects, peak exercise systolic and diastolic blood pressures and delta systolic blood pressure (rest to peak exercise) were higher in men than in women and were positively associated with age. In men, the 90th percentile of systolic blood pressure increased from 210 mm Hg for the age decade 20 to 29 years to 234 mm Hg for ages 70 to 79 years; the corresponding increase among women was from 180 mm Hg to 220 mm Hg. Delta diastolic blood pressure also increased with advancing age. The difference in peak and delta systolic blood pressures between men and women seemed to decrease after age 40 to 49 years. Exercise hypotension, defined as peak exercise systolic pressure less than rest systolic pressure, occurred in 0.23% of men and 1.45% of women and was not significantly related to age. CONCLUSION Overall, peak exercise systolic and diastolic, as well as delta systolic, blood pressures were higher in men than in women and increased with advancing age. The reported data will enable clinicians to interpret more accurately the significance of peak exercise blood pressure response in a subject of a specific age and gender and will allow investigators to define exercise hypertension in statistical terms stratified by age and gender.

Intensive Multifactorial Intervention for Stable Coronary Artery Disease Optimal Medical Therapy in the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) Trial

OBJECTIVES This paper describes the medical therapy used in the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial and its effect on risk factors. BACKGROUND Most cardiovascular clinical trials test a single intervention. The COURAGE trial tested multiple lifestyle and pharmacologic interventions (optimal medical therapy) with or without percutaneous coronary intervention in patients with stable coronary disease. METHODS All patients, regardless of treatment assignment, received equivalent lifestyle and pharmacologic interventions for secondary prevention. Most medications were provided at no cost. Therapy was administered by nurse case managers according to protocols designed to achieve predefined lifestyle and risk factor goals. RESULTS The patients (n = 2,287) were followed for 4.6 years. There were no significant differences between treatment groups in proportion of patients achieving therapeutic goals. The proportion of smokers decreased from 23% to 19% (p = 0.025), those who reported <7% of calories from saturated fat increased from 46% to 80% (p < 0.001), and those who walked >or=150 min/week increased from 58% to 66% (p < 0.001). Body mass index increased from 28.8 +/- 0.13 kg/m(2) to 29.3 +/- 0.23 kg/m(2) (p < 0.001). Appropriate medication use increased from pre-randomization to 5 years as follows: antiplatelets 87% to 96%; beta-blockers 69% to 85%; renin-angiotensin-aldosterone system inhibitors 46% to 72%; and statins 64% to 93%. Systolic blood pressure decreased from a median of 131 +/- 0.49 mm Hg to 123 +/- 0.88 mm Hg. Low-density lipoprotein cholesterol decreased from a median of 101 +/- 0.83 mg/dl to 72 +/- 0.88 mg/dl. CONCLUSIONS Secondary prevention was applied equally and intensively to both treatment groups in the COURAGE trial by nurse case managers with treatment protocols and resulted in significant improvement in risk factors. Optimal medical therapy in the COURAGE trial provides an effective model for secondary prevention among patients with chronic coronary disease. (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation; NCT00007657).

Coronary heart disease in situs inversus totalis

Abstract In patients with dextrocardia as a part of situs inversus totalis, coronary heart disease may occur with similar frequency and manifestations as in the general population. Diagnostic problems arise from the altered cardiovisceral relation; when these are recognized, coronary heart disease can be defined by the usual criteria. The use of electrocardiographic and vectorcardiographic tracings with right-left reversal of all leads in patients with dextrocardia allows the recognition of abnormalities on the basis of standard criteria. Seven cases are reported, 1 followed up clinically and 6 studied at autopsy.

Niacin-Induced Hepatitis: A Potential Side Effect With Low-Dose Time-Release Niacin

Hepatitis developed in five patients who were taking low dosages (3 g/day or less) of time-release niacin. In four of the five patients, clinical symptoms of hepatitis developed after the medication had been taken for a relatively short time (2 days to 7 weeks). This manifestation of hepatotoxicity seems to differ from that previously reported in association with use of crystalline niacin, which occurred with high dosage and prolonged usage of the medication. In view of the recent increased frequency of prescribing niacin for the treatment of hyperlipidemia, physicians should be aware of the potential for hepatotoxicity with even low-dose and short-term use of time-release niacin.

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.

Effect of Intervention for Psychological Distress on Rehospitalization Rates in Cardiac Rehabilitation Patients

Psychosocial factors affect the development of coronary heart disease and morbidity and mortality of patients with known coronary heart disease. A prior study has shown that psychological distress in patients with known coronary heart disease increased medical and economic costs. This study examined the effects of commonly available psychological interventions offered to patients entering cardiac rehabilitation after hospitalization for angina, myocardial infarction, angioplasty, or coronary artery bypass grafting. A total of 380 patients were screened with the Symptom Checklist-90-Revised (SCL-90-R). Those with T-scores > or = 63 (> or = 91 percentile) on the General Severity Index (GSI) subscale were randomly assigned to usual care or special intervention. Special intervention included a psychiatric evaluation, plus one to seven sessions of behavioral therapy. The percentage of patients rehospitalized for cardiac symptoms within 12 months of psychological evaluation was 43% for special intervention and 40% for usual care (NS). A correction for crossover between the treatment groups resulted in a favorable trend toward intervention, with 35% of the psychologically treated patients rehospitalized vs. 48% of the untreated patients (NS). Although there was a nonsignificant reduction of the SCL-90-Rs GSI T-score, the depression score was significantly reduced in the special intervention group.