The safety and efficacy of early-initiation exercise training after acute venous thromboembolism: a randomized clinical trial.

BACKGROUND: Exercise training after myocardial infarction is the standard of care within a cardiac rehabilitation setting. However, there is scant evidence regarding the safety and efficacy of early exercise training following a venous thromboembolism (VTE). METHODS: Eligible consenting participants were randomly allocated, on an individual basis, to either a 3-month exercise and behavioral weight loss intervention group or a control group. The primary clinical outcomes were change in health behavior (body weight and physical activity) and objectively measured fitness (Vo2peak ). RESULTS: From 2013 to 2014, 239 patients presented to a community-based specialty clinic after an acute VTE; 43 (18%) of these met the eligibility criteria for inclusion in the study. Of these, 19 (44%) consented to participate (nine in the intervention group; 10 in the control group). There were no adverse events in either group over a 3-month period. The mean difference in body weight between the intervention and control groups was - 4.6 kg (95% confidence interval [CI] - 11.4 to 2.2) in favor of the intervention. The mean difference in duration of physical activity from baseline to 3 months between the intervention and control groups was 133 min (95% CI 7-248) in favor of the intervention. There was a significant change in fitness over a 3-month period for the intervention group (baseline Vo2peak , 26.1 ± 5.4 mL O2 kg(-1)  min(-1) ; postintervention Vo2peak , 29.8 ± 5.4 mL O2 kg(-1)  min(-1) ). CONCLUSION: Early initiation of exercise training resulted in improvements in physical activity and fitness, and did not result in adverse events while individuals were receiving therapeutic anticoagulation. These are the first data on initiation of an exercise training and behavioral weight loss program in the early post-VTE setting.

The influence of obesity and consequent insulin resistance on coronary risk factors in medically treated patients with coronary disease.

OBJECTIVE: Obesity promotes the development and progression of coronary heart disease (CHD), in part, through its association with hyperlipidemia, hypertension, clotting abnormalities and insulin resistance. We assessed whether these relationships persist in patients with established CHD treated with evidence-based preventive pharmacologic therapies. DESIGN AND SUBJECTS: We performed a cross-sectional study of 74 adults with CHD and a body mass index (BMI) of >27 kg m(-2) (mean 32+/-4). The mean age of subjects was 64+/-9 years (range 44-84 years). MEASUREMENTS: Obesity measures included weight, BMI, waist, fat mass, intra-abdominal fat and subcutaneous fat. Risk factor measures included insulin sensitivity, fasting insulin level, lipid profiles, blood pressure, C-reactive protein (hs-CRP), plasminogen activator inhibitor (PAI-1) and platelet reactivity. Medication use included aspirin (99%), statin (84%), beta-blocker (71%), ACE inhibitor or blocker (37%) and clopidogrel (28%). RESULTS: There was no direct relationship between obesity parameters and risk factor measures of lipid concentrations, blood pressure, clotting abnormalities or platelet reactivity except for a modest relationship between visceral fat and hs-CRP (r=0.30, P=0.02). However, increased BMI, waist circumference, fat mass, total abdominal fat and abdominal subcutaneous fat all correlated with insulin sensitivity (r-values -0.30 to -0.45, P-values 0.01 to <0.001) and insulin concentrations. Insulin sensitivity, in turn, was the best predictor of PAI-1, triglycerides, high-density lipoprotein (HDL) levels, cholesterol/HDL levels (all P<0.01) and platelet reactivity (R=0.34, P=0.02). CONCLUSIONS: Use of preventive pharmacologic therapies obviated the expected relationship between adiposity and CHD risk factors. However, a residual effect of insulin resistance is left untreated. Total adiposity and central adiposity were strong predictors of insulin sensitivity, which in turn predicted cardiac risk factors such as lipid concentrations, PAI-1 and platelet reactivity. Thus, while evidence-based pharmacologic treatments may diminish the statistical relationship between obesity and many cardiac risk factors, adiposity negatively impacts CHD risk by reducing tissue insulin sensitivity.

Interactions of herbal remedies with prescription cardiovascular medications.

Herbal medicinal use has increased dramatically in recent years. The increasing use of these products is of concern, and their use may not be recognized by the treating physicians. Many of these remedies have potential for adverse interactions with medications commonly prescribed for various cardiovascular disorders. Despite their widespread use, limited data exists regarding the efficacy of herbs such as echinacea, garlic, ginseng, gingko, ephedra, and St. John's wort. Of special concern is the ability of herbal remedies to potentiate effects of prescription drugs with a narrow margin of safety. An increasing awareness of the potential for harmful effects of herbal remedies has given the impetus for aggressive interventions to inquire about the use of these agents and systematic reporting of adverse events emanating from their use. This review briefly summarizes important adverse interactions of commonly used herbal remedies with prescription cardiovascular medications.

Exercise rehabilitation of older patients with cardiovascular disease.

As the population of elderly patients with cardiovascular disease continues to increase, much research needs to be done with the goal of maintaining physical functioning and personal independence in this population. It is of particular importance to determine whether training programs can improve physical functioning in the most severely disabled older coronary patients. Effects of cardiac rehabilitation programs on other outcome measures, including psychosocial outcomes, lipid levels, insulin levels, and body composition require better study. Finally, the economic benefits of cardiac rehabilitation in the older coronary patients has received little attention, although early reports are promising. In summary, the older population with coronary disease is characterized by high rates of disability. Exercise training has been demonstrated to be safe and to improve strength, aerobic fitness capacity, endurance and physical function. It remains to be seen whether exercise training can reverse or prevent disability in a broad population of older patients with cardiovascular disease. If successful, cardiac rehabilitation programs will pay great medical, social, and economic dividends in this population.

Contribution of abdominal adiposity to age-related differences in insulin sensitivity and plasma lipids in healthy nonobese women.

OBJECTIVE: We examined the hypothesis that an age-related increase in the compartments of visceral fat would account, in part, for the deleterious changes in insulin sensitivity and blood lipid profile in nonobese women. RESEARCH DESIGN AND METHODS: We directly assessed visceral and subcutaneous abdominal adipose tissue areas (computed tomography), glucose disposal (hyperinsulinemic-euglycemic clamp), body composition (dual energy X-ray absorptiometry), blood-lipid profile, and aerobic fitness (VO2max) in 178 nonobese women categorized into four age groups: group 1, 28 +/- 4 years, n = 88; group 2, 46 +/- 2 years, n = 38; group 3, 53 +/- 2 years, n = 31; and group 4. 67 +/- 6 years, n = 21. RESULTS: Visceral abdominal adipose tissue area increased with age (2.36 cm2 per year, P < 0.0001). We noted an age-related increase in total cholesterol (P < 0.0003), triglycerides (P < 0.0009), LDL cholesterol (P < 0.027), and the ratio of total cholesterol to HDL cholesterol (P < 0.042). However, age-related changes in insulin sensitivity exhibited a different age-related pattern. That is, insulin sensitivity, expressed on an absolute basis or indexed per kilogram of fat-free mass, was lowest in group 4 but was not significantly different among groups 1, 2, and 3. After statistical control for visceral fat, lower insulin sensitivity persisted in group 4, although differences were diminished relative to other groups. However, the effect of visceral fat on age-related changes in the blood-lipid profile was stronger. That is, differences in visceral and deep subcutaneous adipose tissue area abolished age-related differences in total cholesterol, triglycerides, and LDL cholesterol. No independent effects of VO2max or leisure-time physical activity on age-related changes in insulin sensitivity or on the blood-lipid profile were noted. CONCLUSIONS: We conclude that 1) visceral fat shows an increase with advancing age, whereas a decrease in insulin sensitivity was noted only in older women; 2) age-related differences in visceral fat explain only a modest part of the decline in insulin sensitivity in nonobese women; and 3) unfavorable changes in plasma lipids were strongly associated with the age-related increase in visceral abdominal adipose tissue.

Low caloric expenditure in cardiac rehabilitation.

BACKGROUND: Total physical activity energy expenditure is a determinant of weight loss and risk factor modification in adults. There has been very little study of physical activity energy expenditure in cardiac rehabilitation populations. METHODS: Exercise-related energy expenditure was calculated in 112 patients with coronary artery disease in an outpatient cardiac rehabilitation program. Gross energy expenditure was estimated with the heart rate/oxygen consumption relation as measured during metabolic exercise testing with expired gas analysis. RESULTS: The average exercise training energy expenditure (ETEE) per cardiac rehabilitation exercise session was quite low at 270 +/- 112 kcal. Baseline fitness level (peak oxygen consumption), body weight, total exercise duration per session, age, and body mass index were all significant determinants of ETEE (r = 0.56 to -0.37, all P <.01). Additionally, patients who had undergone coronary bypass surgery and patients with medical comorbidities expended significantly fewer calories during exercise. In women, there was a relation between ETEE and change in total and LDL cholesterol (r = -0.43 and -0.45, respectively), although no such relation was observed in men. CONCLUSION: Cardiac rehabilitation exercise training, as currently structured, burns surprisingly few calories and has little impact in the short term (3 months) on measures of obesity and lipid risk factors. Alternative training programs should be considered to maximize caloric expenditure and modify specific risk factors such as obesity and dyslipidemia.

Effects of resistance training and endurance training on insulin sensitivity in nonobese, young women: a controlled randomized trial.

We examined the effects of a 6-month randomized program of endurance training (n = 14), resistance training (n = 17), or control conditions (n = 20) on insulin sensitivity in nonobese, younger women (18-35 yr). To examine the possible mechanism(s) related to alterations in insulin sensitivity, we measured body composition, regional adiposity, and skeletal muscle characteristics with computed tomography. We observed no changes in total body fat, sc abdominal adipose tissue, or visceral adipose tissue with endurance or resistance training. Insulin sensitivity, however, increased with endurance training (pre, 421 +/- 107; post, 490 +/- 133 mg/min; P < 0.05) and resistance training (pre, 382 +/- 87; post, 417 +/- 89 mg/min; P = 0.06). When the glucose disposal rate was expressed per kg fat-free mass (FFM), the improved insulin sensitivity persisted in endurance-trained (pre, 10.5 +/- 2.7; post, 12.1 +/- 3.3 mg/min x kg FFM; P < 0.05), but not in resistance-trained (pre, 9.7 +/- 1.9; post, 10.2 +/- 1.8 mg/min x kg FFM; P = NS) women. Muscle attenuation ratios increased (P < 0.05) in both endurance- and resistance-trained individuals, but this was not related to changes in insulin sensitivity. Moreover, the change in insulin sensitivity was not related to the increased maximum aerobic capacity in endurance-trained women (r = 0.24; P = NS). We suggest that both endurance and resistance training improve glucose disposal, although by different mechanisms, in young women. An increase in the amount of FFM from resistance training contributes to increased glucose disposal probably from a mass effect, without altering the intrinsic capacity of the muscle to respond to insulin. On the other hand, endurance training enhances glucose disposal independent of changes in FFM or maximum aerobic capacity, suggestive of an intrinsic change in the muscle to metabolize glucose. We conclude that enhanced glucose uptake after physical training in young women occurs with and without changes in FFM and body composition.

Modest effects of exercise training alone on coronary risk factors and body composition in coronary patients.

BACKGROUND: Cardiac rehabilitation programs have evolved to become secondary prevention centers. However, the independent effect of exercise alone on coronary risk factors and body composition in patients with coronary artery disease has not been well studied. OBJECTIVE: The aim of this study was to determine the effect of exercise training alone, without modification of dietary intake, on coronary risk factors and body composition in a coronary population. METHODS: The authors studied 82 coronary patients (23 females and 59 males) aged 61.2 +/- 12.2 years (mean +/- SD) before and after a 3-month exercise training program. Outcome variables included serum lipid values, glucose, insulin, body composition, body fat distribution, macronutrient intake, and peak aerobic capacity. RESULTS: Neither male nor female patients experienced a significant overall improvement in plasma cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, glucose, or insulin levels after the 3-month exercise training program. Dietary macronutrient intake was unaltered during the study period. Peak aerobic capacity increased by 3.4 +/- 4.7 ml/kg/min (17%, P < 0.0001) and high-density lipoprotein (HDL)-cholesterol increased from 38 +/- 10 to 41 +/- 11 mg/dL (8%, P < 0.001) after the rehabilitation program. Patients with baseline triglyceride levels over 200 mg/dL experienced a 22% decrease (from 374 +/- 205 to 293 +/- 190 mg/dL; P < 0.05) after conditioning. Patients with baseline HDL-cholesterol levels under 35 mg/dL also improved overall by 17% (from 29 +/- 3 to 34 +/- 5 mg/dL; P < 0.0001). Exercise-induced changes in plasma HDL-cholesterol were more related to changes in body composition and/or body fat distribution, rather than changes in peak aerobic capacity. CONCLUSION: Exercise conditioning alone resulted in relatively modest risk factor improvements in coronary patients after 3 months. High-density lipoprotein cholesterol measures increased by 3 +/- 8 mg/dL (8%). Patients with baseline triglyceride elevations experienced a 22% decrease. On the other hand, there were no overall effects on body weight, total cholesterol, LDL-cholesterol, triglycerides, glucose, or insulin levels. For most patients, exercise effects were minimal and nutritional and medical therapy will need to be used more aggressively to attain nationally recognized risk factor goals.

Coronary risk profiles in men with coronary artery disease: effects of body composition, fat distribution, age and fitness.

BACKGROUND: Few studies have investigated the influence of body composition, abdominal obesity, age and fitness on coronary risk factors in populations of patients with coronary heart disease (CHD). We investigated whether abdominal obesity or generalized adiposity is a better predictor of cardiovascular risk in men with coronary artery disease (CAD), and the effects of exercise training on coronary risk factors in younger and older patients with CAD. METHODS: The study population consisted of 81 male patients aged 33-83 years (mean +/- SD 60.0 +/- 13.3 years) with established CAD. We studied the relationships among body composition, body fat distribution, dietary intake, peak aerobic capacity, lipid concentrations, and plasma glucose and insulin concentrations. We subsequently measured the influence of exercise training on these components. RESULTS: The study population was characterized by a high prevalence of obesity, particularly in younger patients. Body mass index, rather than body fat distribution, was the best anthropometric predictor of plasma triglyceride concentrations (r2 = 0.11, P < 0.05) and cholesterol/high-density lipoprotein cholesterol (HDL-C) ratio (r2 = 0.13, P < 0.01). Body weight, rather than body fat distribution, was the best predictor of plasma HDL-C concentration (r2 = 0.14, P < 0.01) and fasting glucose concentrations (r2 = 0.10, P < 0.05). Fat mass was the best anthropometric predictor of fasting plasma insulin concentrations (r2 = 0.38, P < 0.0001) and for the glucose-insulin ratio (r2 = 0.39, P < 0.0001) in men with CAD. Younger patients tended to have greater improvements in HDL-C concentrations and the cholesterol:HDL-C ratio than did older individuals, as a result of exercise training. CONCLUSION: In men with CAD, general measures of obesity, such as body weight, body mass index, and fat mass are better predictors of coronary risk factors than body fat distribution. Younger and older men with CAD experienced similar improvements in body composition and body fat distribution after an exercise training program.

Obesity, body fat distribution, and coronary artery disease.

Obesity is an independent risk factor for the development of coronary artery disease (CAD). Obesity also increases risk for CAD indirectly through its association with insulin resistance, hyperlipidemia, and hypertension. An increased accumulation of fat in the intraabdominal cavity, termed visceral adiposity, is highly correlated with an adverse coronary risk profile. In patients at risk for coronary artery disease, the treatment of obesity results in an improved coronary risk profile. The prevalence of obesity is extremely high in coronary populations, yet the effect of weight loss on cardiovascular outcomes in CAD patients has received relatively little attention. Observational studies in the cardiac rehabilitation setting showed that patients who lose weight and exercise show an improvement in coronary risk profile. Further research is needed to better define the clinical effectiveness of weight loss programs and their benefits in coronary patients.

Home resistance training in an elderly woman with coronary heart disease.

In the current report, a home-based resistive exercise training program was designed for an older woman with coronary artery disease and chronic heart failure, who was unable to participate in a center-based program. With intermittent on-site instruction, the patient was able to learn and perform the designed exercise program. After 6 months of exercise, muscle strength (handgrip and leg extension) and lean body mass were increased, and indicators of physical functional performance were improved. We conclude that a home resistive-based exercise program, with intermittent on-site exercise counseling, may be an effective method for physical training in older coronary patients unable to travel to a rehabilitation center. Further study of this intervention in a controlled clinical trial appears warranted.

Respiratory fitness, free living physical activity, and cardiovascular disease risk in older individuals: a doubly labeled water study.

The objective of this study was to examine the importance of cardiorespiratory fitness vs. physical activity energy expenditure on selected cardiovascular disease risk factors in older individuals. One hundred and seventeen older individuals, 53 men (68 +/- 9 yr) and 63 women (67 +/- 7 yr), participated in the study. This cohort was divided into 4 groups: 1) high cardiorespiratory fitness and high physical activity, 2) high cardiorespiratory fitness and low physical activity, 3) low cardiorespiratory fitness and high physical activity, and 4) low cardiorespiratory fitness and low physical activity. Cardiorespiratory fitness (VO2max) was determined from a graded exercise test, physical activity energy expenditure was measured by doubly labeled water and indirect calorimetry, body composition was determined by dual energy x-ray absorptiometry, and dietary practices were determined by a 3-day recall. Cardiorespiratory fitness exerted greater effects on the cardiovascular disease risk profile than physical activity. That is, older individuals with higher levels of cardiorespiratory fitness, regardless of their physical activity levels, showed lower levels of fasting insulin (P < 0.01), triglycerides (P < 0.05), total cholesterol (P < 0.05), total to high density lipoprotein cholesterol ratio (P < 0.05), low density lipoprotein (P < 0.05), and lower waist circumference (P < 0.01). Moreover, individuals with a high cardiorespiratory fitness but low physical activity energy expenditure displayed a more favorable cardiovascular disease risk profile than individuals with low cardiorespiratory fitness and high physical activity energy expenditure. The results suggest that higher levels of cardiorespiratory fitness have greater cardioprotective effects than higher levels of free living physical activity in older individuals. Although these findings do not discount the health benefits of being physically active, it is possible that greater emphasis should be placed on aerobic exercise to increase cardiorespiratory fitness in the elderly.

A controlled trial of cardiac rehabilitation in the home setting using electrocardiographic and voice transtelephonic monitoring.

OBJECTIVE: The goal of this study was to compare the effectiveness of home-based, transtelephonically monitored cardiac rehabilitation with standard, on-site, supervised cardiac rehabilitation. BACKGROUND: Participation in cardiac rehabilitation has been demonstrated to increase exercise capacity, decrease cardiovascular symptoms, improve psychosocial status, and decrease total and cardiovascular mortality rates in patients with coronary heart disease. Because of multiple factors, national overall participation is only at 15% of eligible patients. METHODS: Effects of a 3-month home-based, transtelephonically monitored rehabilitation program (n = 83 patients) with simultaneous voice and electrocardiographic transmission to a centrally located nurse coordinator were compared with effects of a standard on-site rehabilitation program (n = 50 patients). The study design was a multicenter, controlled trial. Primary outcome variables were peak aerobic capacity and quality of life, as measured by the Health Status Questionnaire. RESULTS: Patients in the home-based monitoring program increased peak aerobic capacity to a similar degree as patients who exercised on site (18% vs 23%). Quality of life domains of physical functioning, social functioning, physical role limitations, emotional role limitations, bodily pain, and energy/fatigue improved similarly in both groups. There were no circulatory arrests or other major exercise-related medical events in either group. A total of 3100 hours of home exercise were transtelephonically monitored. CONCLUSIONS: Patients with coronary heart disease can effectively participate in home-based, monitored cardiac rehabilitation, with exercise and quality of life improvements comparable to those demonstrated at on-site programs.

Effects of exercise and cardiac rehabilitation on cardiovascular outcomes.

Comprehensive cardiac rehabilitation for coronary patients includes a systematic approach to the measurement and treatment of coronary risk factors, along with the better-known exercise training component. Studies of exercise and nutritional interventions in patients with coronary heart disease have documented improved primary outcomes of decreased morbidity and mortality, decreased symptoms, and fewer cardiac rehospitalizations. Quality of life, depression scores, and physical functioning are improved after rehabilitation.

Prevalence, predisposing factors, and prognosis of clinically unrecognized myocardial infarction in the elderly.

OBJECTIVES: This study was designed to determine the prevalence of unrecognized myocardial infarction (UMI), as well as risk factors, and to compare prognosis after detection of previously UMI to that after recognized myocardial infarction (RMI). BACKGROUND: Past studies revealed that a significant proportion of MIs escape recognition, and that prognosis after such events is poor, but the epidemiology of UMI has not been reassessed in the contemporary era. METHODS: The Cardiovascular Health Study (CHS) database, composed of individuals > or =65, was queried for participants who, at entry, demonstrated electrocardiographic evidence of a prior Q-wave MI, but who lacked a history of this diagnosis. The features and outcomes of this group were compared to those of individuals with prevalent RMI. RESULTS: Of 5,888 participants, 901 evidenced a past MI, and 201 (22.3%) were previously unrecognized. The independent predictors of UMI were the absence of angina and the absence of congestive heart failure (CHF). Six-year mortality did not significantly differ between the two groups. CONCLUSIONS: 1) In the elderly, UMI continues to represent a significant proportion of all MIs; 2) associations with angina and CHF may reflect complex neurological issues, but they also may represent diagnosis bias; 3) these individuals can otherwise not be distinguished from those with recognized infarctions; and 4) mortality rates after UMI and RMI are similar. Future studies should address screening for UMI, risk stratification after detection of previously UMI, and the role of standard post-MI therapies.