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To determine if older, asymptomatic individuals with no prior history of coronary heart disease with exercise-induced silent myocardial ischemia (SI) during graded exercise treadmill testing exhibit exaggerated cardiovascular reactivity to anger provocation, we compared 42 SI participants and 95 controls. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) changes from baseline to three tasks--anger recall, speech role-play, and mental arithmetic with harassment--were assessed. Compared to controls, SI displayed greater HR responses for the speech role-play task only. The SI group was significantly older, had higher levels of fasting glucose and triglycerides, and had lower HDL-cholesterol. In multiple regression analyses, after controlling for these differences, SI was significantly associated with greater HR responses to the speech role-play. In sum, the SI group significantly exaggerated HR responses to the speech role-play task, whereas SBP and DBP reactivity were comparable between groups. This suggests minimally enhanced cardiovascular reactivity among older SI patients that may nonetheless increase risk for cardiac events.

Silent myocardial ischemia (SI) has been linked to increased risk of future coronary events. Enhanced systolic and diastolic blood pressure (SBP and DBP, respectively) and heart-rate (HR) reactions to stress (cardiovascular reactivity [CVR]) have been associated with greater severity of SI and are related prospectively to coronary-artery-disease endpoints. The authors examined the potential attenuating effects of 6 months of walking (aerobic exercise) versus control on CVR to three laboratory stressors in 25 older adults with exercise-induced SI. Maximal aerobic capacity was significantly improved by 12% for the exercise group and decreased by 8% for controls (p < .001). Groups had similar biomedical profiles pre- and postintervention. Walkers had significantly reduced DBP reactivity (pre, 12 +/- 2; post, 4 +/- 2 mm Hg) compared with controls (pre, 10 +/- 2; post, 11 +/- 2 mm Hg; p = .05), but no differences between groups were found for SBP or HR reactivity. These findings are the first to suggest that increased physical activity (via walking) can attenuate BP reactivity to emotional stressors in apparently healthy older adults with SI.

Objectives: To determine whether exercise-induced silent ischemia in older master athletes following a 3-month period of deconditioning is a predictor of future cardiovascular events., Design: A longitudinal study of a cohort of master athletes., Setting: The Geriatric Research Education and Clinical Center (GRECC), Baltimore VA Medical Center, Baltimore, Maryland., Participants: Ten older (59 +/- 8 years, mean +/- SD), highly conditioned (maximal aerobic capacity VO2max 50 +/- 5 mL/kg/min), aerobically trained athletes., Intervention: Five to eight years of longitudinal follow-up of athletes who had previously participated in a 3-month-long detraining intervention., Measurements: At baseline, all 10 athletes had their history taken and underwent physical examinations, metabolic testing, electrocardiogram at rest, exercise treadmill tests, exercise thallium scintigrams, and exercise multigated acquisition scans. After 3 months of deconditioning, they had repeat maximal exercise stress tests. After 5 to 8 years of follow-up, they were re-evaluated, including history and physical examination and measurement of their VO2max., Result: All 10 master athletes had normal studies at baseline. At the end of 3 months of detraining, three of these athletes had exercise-induced silent ischemia, which disappeared after retraining in two subjects and persisted at a higher heart rate in one subject. Over a 5- to 8-year period of observation, two of these three athletes with silent ischemia experienced major cardiac events (sudden death, cardiac bypass surgery). The other seven athletes did not have any cardiovascular events., Conclusions: Exercise-induced silent ischemia after a short period of detraining in highly trained older athletes may be a predictor of future cardiac events. A study with a larger cohort is warranted.

Objectives: Before men older than age 45 participate in vigorous exercise programs, the American Heart Association and the American College of Sports Medicine recommend they undergo a screening maximal exercise treadmill test. We examined the predictive value for subsequent cardiac events of exercise-induced silent myocardial ischemia (SI) during the exercise treadmill test in healthy, sedentary, obese, middle-aged and older men recruited for research studies., Design: A cohort study with 7 years of follow-up., Setting: Out-patient research at a tertiary hospital., Participants: 170 healthy, sedentary, obese, middle-aged and older (ages 45-79 years) men with no prior history of coronary artery disease (CAD) recruited for research studies., Measurements: Cardiac risk factors, exercise-induced SI (ST segment depression on the electrocardiogram during a maximal exercise treadmill test), maximal aerobic capacity (VO2max), and 7- year follow-up data on incident CAD., Results: At baseline, 37 of the men (22%) had exercise-induced SI on their treadmill tests. Seven-year follow-up data was obtained in 97% of the patients. In the interim, 31 men had cardiac endpoints (sudden cardiac death, myocardial infarction, angioplasty, coronary artery bypass graft surgery, angina), and four had noncardiac deaths. Seventeen of the 37 men (46%) with exercise-induced SI on their baseline exercise tests had cardiac endpoints compared with 14 of 133 (11%) men with normal exercise tests (P < .001). Compared with the men with no cardiac endpoints, the men with subsequent cardiac endpoints were older (63 +/- 1 vs 58 +/- 1 years, mean +/- SEM, P < .001) and had a lower maximal aerobic capacity (VO2max) (24 +/- 1 vs 29 +/- 1 mL/kg/min, P < .001). In Cox proportional hazards analysis, exercise-induced SI and a low VO2max were independent predictors of subsequent cardiac endpoints., Conclusion: In a healthy population of obese, sedentary, middle-aged and older men, exercise-induced SI and low VO2max were predictors of incident CAD. This suggests that exercise treadmill testing is beneficial in assessing risk for future cardiac events in obese, sedentary individuals.

High-physical activity levels are associated with reduced risk of symptomatic coronary artery disease (CAD). However, there are a number of reports of exercise-related sudden death and myocardial infarction in aerobically trained athletes. This study compared the prevalence of exercise-induced silent myocardial ischemia on maximum graded exercise tests with tomographic thallium scintigraphy in 70 master male athletes (63 +/- 6 years, mean +/- SD) (maximum aerobic capacity, VO2max >40 ml/kg/min) and in 85 healthy untrained men (61 +/- 7 years) with no history of CAD. The prevalence of silent ischemia (exercise-induced ST-segment depression on electrocardiogram and perfusion abnormalities on thallium scintigraphy) was similar in athletes and untrained men; 16% of the athletes (11 of 70) had silent ischemia compared with 21% of the untrained men (chi-square = 0.81, p = 0.36). No athletes had hyperlipidemia, systemic hypertension, or diabetes mellitus. However, the apolipoprotein E4 allele was present in 9 of the 11 athletes with silent ischemia compared with 2 of 32 athletes with normal exercise tests (chi-square = 24, p = 0.0001). These results suggest that older male athletes with the apolipoprotein E4 allele are at increased risk for the development of exercise-induced silent ischemia.

Reduced plasma concentrations of high-density lipoprotein cholesterol (HDL-C) are a risk factor for coronary artery disease (CAD). In this study, we examined the sequential effects of an isocaloric American Heart Association (AHA) step I diet and a hypocaloric AHA step I diet (AHA step I diet + weight loss) on lipoprotein lipid levels in 14 middle-aged and older (60 +/- 6 years, mean +/- SD) obese (body mass index [BMI] > 27 kg/m2) nondiabetic men with exercise-induced silent myocardial ischemia (SI) and reduced HDL-C levels (0.85 +/- 0.14 mmol/L). Nine men of comparable age and obesity and with no evidence of exercise-induced ischemia that were evaluated longitudinally served as metabolic controls. In men with SI, after 3 months on the isocaloric AHA step I diet plasma triglyceride (TG) levels decreased by 26% (2.25 +/- 0.66 to 1.67 +/- 0.69 mmol/L, P < .005), cholesterol by 12% (5.24 +/- 0.84 to 4.62 +/- 0.78 mmol/L, P < .01), and low-density lipoprotein cholesterol (LDL-C) by 10% (3.40 +/- 0.69 to 3.05 +/- 0.70 mmol/L, P < .01). However, plasma HDL-C levels also decreased by 7% (0.85 +/- 0.14 to 0.79 +/- 0.13 mmol/L, P < .05). Subsequent weight loss (11 +/- 4 kg) in conjunction with the AHA step I diet resulted in an additional decrease of 24% in TG (P < .005), 10% in cholesterol (P < .05), and 10% in LDL-C (P < .05). Plasma HDL-C levels increased by 8% (P < .01), thereby correcting the decline seen on the AHA step I diet alone.(ABSTRACT TRUNCATED AT 250 WORDS)

This study determined the risk factors for exercise-induced silent ischemia (SI) in 281 apparently healthy volunteers aged 40 to 87 years and compared their risk factor profiles with those of 132 patients with overt coronary artery disease (CAD). SI (concordant exercise-induced asymptomatic ST-segment depression on electrocardiography and perfusion defects on tomographic thallium-201 scintigraphy) was detected in 37 of 225 men (16%), versus 2 of 56 women (4%, p < 0.05). The prevalence of SI increased with age from 6% in men aged < 55 years to 18% in men aged 55 to 70 years, and to 25% in men aged > 70 years (p < 0.001). Compared with the 118 men with concordant normal exercise electrocardiogram and thallium scan (normals), men with SI were older (p < 0.001), and had a higher waist-to-hip ratio (p < 0.005), higher plasma triglyceride levels (p < 0.001), and lower high-density lipoprotein (HDL) cholesterol levels (p < 0.001). In stepwise logistic regression analysis, age, waist-to-hip ratio, and HDL levels were independent predictors of SI in men. Compared with 108 men with overt CAD, men with SI were younger (67 +/- 2 vs 73 +/- 1 years, p < 0.001) but had similar plasma lipids and waist-to-hip ratio. Thus, older age, male gender, abdominal obesity, and reduced HDL levels--all well-established risk factors for overt CAD--were risk factors for exercise-induced SI in these asymptomatic volunteers.

Healthy older (64 +/- 1 years, mean +/- SEM) athletic (maximal oxygen consumption [VO2max] > 40 mL/kg/min) normocholesterolemic men with no prior history of coronary artery disease (CAD) were recruited for cardiovascular and metabolic studies. Thirty-three percent had asymptomatic exercise-induced ST segment depression on their exercise electrocardiogram (ECG), consistent with silent myocardial ischemia (SI). We hypothesized that abnormalities in high-density lipoprotein (HDL) and postprandial triglyceride (TG) metabolism may increase their risk for CAD. Compared with 12 nonischemic controls of comparable age, percent body fat, and VO2max, the 13 men with SI had decreased fasting HDL cholesterol ([HDL-C] 41 +/- 2 v 50 +/- 2 mg/dL, P < .001) and %HDL2b subspecies levels as measured by gradient gel electrophoresis (22 +/- 2 v 34 +/- 3, P < .001). Fasting plasma TG and low-density lipoprotein cholesterol (LDL-C) levels were the same in both groups. Although plasma glucose levels during an oral glucose tolerance test (OGTT) were similar in both groups, the total insulin area was higher in men with SI (P < .05). After consumption of a standard high-fat meal (680 kcal/m2 body surface area of a formula in which 86% of the calories were derived from fat), postprandial plasma TG, chylomicron-TG, and very-low-density lipoprotein (VLDL)-TG levels and postprandial areas were higher in men with SI (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

The apolipoprotein (apo) E4 polymorphism is associated with increased risk for symptomatic coronary artery disease (CAD). This study examines whether the apo epsilon allele is associated with an increased risk for exercise-induced silent myocardial ischemia (SI) in healthy, older (62 +/- 7 years; mean +/- SD), normocholesterolemic, nonsmoking male volunteers. The apo epsilon 4 allele was present in 20 of 45 (44%) men with SI on graded exercise treadmill testing compared with 22 of 127 (17%) men of comparable age with normal exercise tests (P < .001), resulting in a crude relative risk of 2.57 (95% confidence limits, 1.57 to 4.23) for SI in men with the apo epsilon 4 allele compared with those without the epsilon 4 allele. Although the lipoprotein lipid levels did not differ between men with normal exercise tests and those with SI, the men with the apoE 4/3 phenotype had higher total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels than those with the apoE 2/3 and 3/3 phenotypes (P < .05). Men with SI and the apoE 4/3 phenotype were older (64 +/- 5 versus 57 +/- 8 years, P < .01) and leaner (P < .01) than the normal non-SI men with the apoE 4/3 phenotype. The older age of the men with SI and the apoE 4/3 phenotype is consistent with a progression of atherosclerosis over time. Men with SI and the apoE 3/3 phenotype were of comparable age and body composition to apoE 3/3 phenotype men with normal exercise tests. Thus, even in the presence of normal LDL-C levels, the apo epsilon 4 allele may predispose older men to SI.