Peak oxygen consumption achieved at the end of cardiac rehabilitation predicts long-term survival in patients with coronary heart disease.

AIMS: Cardiac rehabilitation (CR) improves survival in patients with coronary heart disease (CHD), which is largely mediated by the improvements in cardiorespiratory fitness (CRF) defined as peak oxygen consumption (VO2). Therefore, measuring CRF is essential to predict long-term outcomes in this population. It is unclear, however, whether peak VO2 achieved at the end of CR (END-peak VO2) predicts survival or whether the changes of CRF achieved during CR provide a greater prognostic value. To determine whether END-peak VO2 independently predicts long-term survival in patients with CHD undergoing CR. We also aimed at identifying cut-offs for END-peak VO2 that could be used in clinical practice. METHODS AND RESULTS: Retrospective analysis of 853 patients with CHD referred to CR who completed a maximal cardiopulmonary exercise test. Survival analysis was performed to examine the risk of all-cause mortality (average follow-up years: 6.65) based on peak VO2. The Contal and O'Quigley's method was used to determine the optimal cut-off of END-peak VO2 based on the log-rank statistic. END-peak VO2 was inversely associated with mortality risk [hazard ratio (HR) = 0.84; 95% confidence interval (CI) = 0.78-0.90], independent of changes in peak VO2 adjusted for the baseline peak VO2. The estimated cut-off of END-peak VO2 at ≥17.6 mL/kg/min best predicted the survival with high predictive accuracy and patients with END-peak VO2 under the cut-off had a greater risk of mortality (HR = 2.93; 95% CI = 1.81-4.74). CONCLUSIONS: In patient with CHD undergoing CR, END-peak VO2 is an independent predictor for long-term survival. Studies utilizing higher intensity CR programmes, with and without pharmacologic strategies, to increase peak VO2 to a greater degree in those achieving a suboptimal END-peak VO2, are urgently needed.

Cardiac rehabilitation fitness changes and subsequent survival.

Aims: Assessments of cardiac rehabilitation (CR) in coronary heart disease (CHD) cohorts usually examine mortality in aggregate. This study examines the prognosis and characteristics of patients who enrolled and completed CR, stratified by their level of improvement in cardiorespiratory fitness (CRF) by examining the characteristics, outcomes and predictors of non-response in CRF (NonRes) compared with low-responders (LowRes) and high-responders (HighRes) after CR. Methods and results: A total of 1171 CHD patients were referred for a phase II CR programme after therapy for an acute coronary syndrome, coronary artery bypass graft procedure or a percutaneous coronary intervention between 1 January 2000 and 30 June 2013 underwent cardiopulmonary exercise testing before and after CR. This cohort was divided according to absolute improvements in CRF (i.e. change in peak oxygen consumption expressed in mL⋅kg-1⋅min-1). Mortality was analysed after 0.5-13.4 years of follow-up (mean 6.4 years). A total of 266 (23%) subjects were NonRes. After adjustment for body mass index, age, gender, left ventricular ejection fraction and baseline CRF, NonRes, and LowRes had a statistically significant three-fold and two-fold higher mortality, respectively, when compared with HighRes (HighRes 8% vs. LowRes 17% vs. NonRes 22%; P < 0.001). Age, female gender, baseline CRF, hostility, and presence of diabetes were significant predictors of NonRes and LowRes. In addition, higher waist circumference was a predictor of NonRes. Conclusion: Significant proportions of subjects referred to CR have no/low improvement in CRF and higher associated mortality risks. Greater attention is required to increase improvements in CRF following CR and avoid NonRes.

Cardiovascular Risk in Patients with Prehypertension and the Metabolic Syndrome.

Prehypertension (pHTN) and metabolic syndrome (MetS) are both lifestyle diseases that are potentiated by increased adiposity, as both disease processes are closely related to weight. In the case of pHTN, increased adiposity causes dysregulation of the renin-angiotensin-aldosterone-system (RAAS) as well as adipokine- and leptin-associated increases in adrenergic tone. In MetS, excess weight potentiates hyperglycemia and insulin resistance which causes positive feedback into the RAAS system, activates an inflammatory cascade that potentiates atherosclerosis, and causes lipid dysregulation which together contribute to cardiovascular disease, especially coronary heart disease (CHD) and heart failure (HF). The relationship with all-cause mortality is not as clear-cut in part because of some protective effects associated with the obesity paradox in chronic diseases such as CHD and HF. However, in healthy populations, the absence of excess weight and its associated effects on prehypertension and MetS are associated with a longer absolute and disease-free lifespan.

Impact of cardiac rehabilitation and exercise training programs in coronary heart disease.

Cardiovascular rehabilitation (CR) is the process of developing and maintaining an optimal level of physical, social, and psychological well-being in order to promote recovery from cardiovascular (CV) illness. It is a multi-disciplinary approach encompassing supervised exercise training, patient counseling, education and nutritional guidance that may also enhance quality of life. Beneficial CV effects may include improving coronary heart disease risk factors; particularly exercise capacity, reversing cardiac remodeling, and favorably modifying metabolism and systemic oxygen transport. We review the historical basis for contemporary CR, the indications and critical components of CR, as well as the potential salutary physiological and clinical effects of exercise-based CR.

Obesity and cardiovascular diseases.

Obesity is increasingly more common in postindustrial societies, and the burden of childhood obesity is increasing. The major effects of obesity on cardiovascular (CV) health are mediated through the risk of metabolic syndrome (insulin-resistance, dyslipidemia, and hypertension), such that an absence of these risk factors in obese individuals may not be associated with increased mortality risk. In individuals already diagnosed with chronic CV disease (CVD), the overweight and class I obese have significant associations with improved survival. However, this effect is attenuated by increases in cardiorespiratory fitness. The negative effects of obesity on CV health manifest as accelerated progression of atherosclerosis, higher rates of ventricular remodeling and a higher risk of associated diseases, including stroke, myocardial infarction, and heart failure. The most effective therapies at reversing CVD risk factors associated with obesity have been dietary changes with exercise, especially through structured exercise programs, such as cardiac rehabilitation.

Impact of Cardiac Rehabilitation and Exercise Training on Psychological Risk Factors and Subsequent Prognosis in Patients With Cardiovascular Disease.

The role of psychological risk factors has been under-recognized in most subspecialties of medicine, as well as in general medicine practices. However, considerable evidence indicates that psychosocial factors are involved in the pathogenesis and progression of cardiovascular disease (CVD). Emerging data from cardiac rehabilitation (CR) settings and CR exercise training (CRET) programs have demonstrated the value of comprehensive CRET to improve psychological functioning and reduce all-cause mortality. Recent evidence also supports the role of CRET and the added value of stress management training in the secondary prevention of CVD.

Significance of Comorbid Psychological Stress and Depression on Outcomes After Cardiac Rehabilitation.

BACKGROUND: Depression is associated with increased mortality in stable coronary heart disease. Cardiac rehabilitation and exercise training has been shown to decrease depression, psychological stress, and mortality after a coronary heart disease event. The presence of depression at completion of cardiac rehabilitation and exercise training is associated with increased mortality. However, it is unknown if depression with comorbid psychological risk factors such as anxiety or hostility confers an additional mortality disadvantage. We evaluated the mortality effect of anxiety and hostility on depression after cardiac rehabilitation and exercise training. PATIENTS AND METHODS: We studied 1150 patients with coronary heart disease following major coronary heart disease events who had completed formal cardiac rehabilitation and exercise training. Using Kellner questionnaires, stress levels were measured in 1 of 3 domains: anxiety, hostility, and depression (with an aggregated overall psychological stress score) and divided into 3 groups: nondepressed (n = 1072), depression alone (n = 18), and depression with anxiety or hostility (n = 60). Subjects were analyzed for all-cause mortality over 161 months of follow-up (mean 6.4 years) by National Death Index. RESULTS: Depression after cardiac rehabilitation was not common (6.8%; mortality 20.8%) but when present, frequently associated with either anxiety or hostility (77% of depressed patients; mortality 22.0%). After adjustment for age, sex, ejection fraction, and baseline peak oxygen consumption, depression alone (hazard ratio [HR] 1.73, P = .04), as well as depression with comorbid psychological stress, was associated with higher mortality (HR 1.98, P = .03). Furthermore, our data showed an increased mortality when both anxiety and hostility were present in addition to depression after cardiac rehabilitation (HR 2.41, P = .04). CONCLUSIONS: After cardiac rehabilitation, depression, when present, is usually associated with other forms of psychological stress, which confers additional mortality. More measures are needed to address psychological stress after cardiac rehabilitation.

Obesity and Prevalence of Cardiovascular Diseases and Prognosis-The Obesity Paradox Updated.

The prevalence and severity of obesity have increased in the United States and most of the Westernized World over recent decades, reaching worldwide epidemics. Since obesity worsens most of the cardiovascular disease (CVD) risk factors, not surprisingly, most CVDs, including hypertension, coronary heart disease, heart failure, and atrial fibrillation, are all increased in the setting of obesity. However, many studies and meta-analyses have demonstrated an obesity paradox with regards to prognosis in CVD patients, with often the overweight and mildly obese having a better prognosis than do their leaner counterparts with the same CVD. The implication for fitness to markedly alter the relationship between adiposity and prognosis and the potential impact of weight loss, in light of the obesity paradox, are all reviewed.

Update on Obesity and Obesity Paradox in Heart Failure.

Obesity has reached epidemic proportions in most of the Westernized world. Overweightness and obesity adversely impact cardiac structure and function, including on both the right and, especially, left sides of the heart, with adverse affects on systolic and, especially, diastolic ventricular function. Therefore, it is not surprising that obesity markedly increases the prevalence of heart failure (HF). Nevertheless, many studies have documented an obesity paradox in large cohorts with HF, where overweight and obese have a better prognosis, at least in the short-term, compared with lean HF patients. Although weight loss clearly improves cardiac structure and function and reduces symptoms in HF, there are no large studies on the impact of weight loss on clinical events in HF, preventing definitive guidelines on optimal body composition in patients with HF.

Lifestyle modification in the prevention and treatment of atrial fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia worldwide and has a significant impact on morbidity and mortality. Additionally, the incidence and prevalence of AF is expected to increase in the United States and worldwide over the next few decades. While the pathophysiology concerning the development of AF is not completely understood, multiple modifiable, as well as non-modifiable risk factors, for AF development have been discovered. The goal of this paper is to provide an overview of the modifiable risk factors that contribute to the development and recurrence of AF, in addition to discussing potential lifestyle changes that may aid in the prevention and treatment of AF.

Healthy obese versus unhealthy lean: the obesity paradox.

Overweight and obesity have reached epidemic proportions in the USA and most of the rest of the world. Particularly concerning is the very high prevalence of class III obesity (BMI ≥40 kg/m(2)), which has reached ∼3% in the USA. In the past few years, controversy has surrounded the idea that some individuals with obesity can be considered healthy with regards to their metabolic and cardiorespiratory fitness, which has been termed the 'obesity paradox'. These controversies are reviewed in detail here, including discussion of the very favourable prognosis in patients with obesity who have no notable metabolic abnormalities and who have preserved fitness. The article also discusses the suggestion that greater emphasis should be placed on improving fitness rather than weight loss per se in the primary and secondary prevention of cardiovascular diseases, at least in patients with overweight and class I obesity (BMI 30-35 kg/m(2)).

Low weight and overweightness in older adults: risk and clinical management.

The prevalence of individuals who are overweight or obese is growing exponentially in the United States and worldwide. This growth is concerning, as both overweightness and obesity lead to impaired physical function, decreased quality of life, and increased risk of chronic diseases. Additionally, overweightness and obesity are related to increased mortality among young and middle-aged adults. This weight-related risk of mortality is more ambiguous among older adults. In fact, obesity may be protective in this population, a relationship described as the "obesity paradox". In this review we discuss the effects of overweightness and obesity among the elderly on cardiovascular disease and all-cause mortality, along with the risks of low weight. We conclude by discussing the goal of weight management among older adults, focusing particularly on benefits of preserving lean body mass and muscular strength while stabilizing body fat. Ideally, overweight or mildly obese elderly individuals should devise a plan with their physicians to maintain their weight, while increasing lean body mass through a plan of healthy diet, behavioral therapy, and physical activity.

Body composition and mortality in a large cohort with preserved ejection fraction: untangling the obesity paradox.

OBJECTIVE: To evaluate the effects of body composition as a function of lean mass index (LMI) and body fat (BF) on the correlation between increasing body mass index (BMI; calculated as the weight in kilograms divided by the height in meters squared) and decreasing mortality, which is known as the obesity paradox. PATIENTS AND METHODS: We retrospectively assessed 47,866 patients with preserved left ventricular ejection fraction (≥50%). We calculated BF by using the Jackson-Pollock equation and LMI using (1 - BF) × BMI. The population was divided according to the sex-adjusted BMI classification, sex-adjusted LMI classification, and sex-adjusted BF tertiles. The population was analyzed by using multivariate analysis for total mortality over a mean follow-up duration of 3.1 years by using the National Death Index, adjusting for left ventricular ejection fraction, left ventricular mass index, age, sex, and relative wall thickness. RESULTS: In the entire population, higher BMI was narrowly associated (hazard ratio [HR], 0.99; P<.001) with lower mortality. The higher LMI group was clearly protective (HR, 0.71; P<.001), whereas BF tertile was associated with lower mortality only if no adjustment was made for LMI (HR, 0.87; P<.001 without LMI; HR, 0.97; P=.23 with LMI). In the lean patients, low BMI was clearly associated with higher mortality (HR, 0.92; P<.001) and lower BF tertile was associated with lower mortality only if no adjustment was made for LMI (HR, 0.80; P<.001 without LMI; HR, 1.01; P=.83 with LMI). The underweight patients stratified by BF seemed to have an increased mortality (HR, 1.91; 95% CI, 1.56-2.34) that was independent of LMI. However, in obese patients, both BMI (HR, 1.03; P<.001) and BF (HR, 1.18; P=.003) were associated with higher mortality, even after adjusting for LMI, which remained protective (HR, 0.57; P<.001) independently of BF. CONCLUSION: Body composition could explain the inverse J shape of the mortality curve noted with increasing BMI. Body fat seems to be protective in this cohort only if no adjustment was made for LMI, although being underweight stratified by BF seems to be an independent risk factor. Lean mass index seems to remain protective in obese patients even when BMI is not.

The relationship between obesity and coronary artery disease.

Obesity continues to be a growing issue in the United States, with an estimated prevalence of 72 million people. There are major health implications associated with obesity, including its relationship with hypertension, diabetes mellitus type 2, metabolic syndrome, and dyslipidemia, all independent risk factors for coronary artery disease (CAD). Despite the increased risk of developing CAD, in recent years an "obesity paradox" has been described in which moderately obese individuals with established cardiovascular disease, including CAD, appear to have mortality similar to their normal-weight counterparts. This review examines the relationship between obesity and CAD, including the increased risk of hypertension, diabetes mellitus, metabolic syndrome, and dyslipidemia, along with a discussion of the obesity paradox and the benefits of weight reduction.

Obesity paradox, cachexia, frailty, and heart failure.

Overweight and obesity adversely affect cardiovascular (CV) risk factors and CV structure and function, and lead to a marked increase in the risk of developing heart failure (HF). Despite this, an obesity paradox exists, wherein those who are overweight and obese with HF have a better prognosis than their leaner counterparts, and the underweight, frail, and cachectic have a particularly poor prognosis. In light of this, the potential benefits of exercise training and efforts to improve cardiorespiratory fitness, as well as the potential for weight reduction, especially in severely obese patients with HF, are discussed.

The impact of obesity on risk factors and prevalence and prognosis of coronary heart disease-the obesity paradox.

Obesity is associated with a host of cardiovascular risk factors and its prevalence is rising rapidly. Despite strong evidence that obesity predisposes to the development and progression of coronary heart disease (CHD), numerous studies have shown an inverse relationship between various measures of obesity (most commonly body mass index) and outcomes in established CHD. In this article we review the evidence surrounding the ≪obesity paradox≫ in the secondary care of CHD patients and the CHD presentations where a paradox has been found. Finally we discuss the impact of cardiorespiratory fitness and a number of mechanisms which may offer potential explanations for this puzzling phenomenon.

Obesity paradox in different populations: evidence and controversies.

An inverse association between BMI and mortality has been reported in patients with coronary heart disease and heart failure. This 'obesity paradox' has recently been reported in other disease states, including stroke, hypertension, incident diabetes, atrial fibrillation, hemodialysis and transcatheter aortic valve replacement. Cardiorespiratory fitness influences the obesity paradox and this inverse association may be present only in individuals with low fitness levels. Intentional weight loss, exercise training and improving lean mass are important and should be advised to all patients. Recent studies have also explored the association between measures of central obesity and direct measures of body fat with mortality. This review will summarize the evidence, controversies and mechanisms associated with the puzzling obesity paradox.