Cardiac rehabilitation in the elderly: patient selection and outcomes

Cardiac Rehabilitation in Advanced aGE after PCI for acute coronary syndromes: predictors of exercise capacity improvement in the CR-AGE ACS study

BACKGROUND

The positive effect of cardiac rehabilitation (CR) on outcomes after acute coronary syndromes (ACS) is established. Nevertheless, enrollment rates into CR programs remain low, although ACS carry a high risk of functional decline particularly in the elderly.

AIM

We aimed to determine if a multidisciplinary CR improves exercise capacity in an older population discharged after ACS systematically treated with PCI.

METHODS

CR-AGE ACS is a prospective, single-center, cohort study. All patients aged 75+ years consecutively referred to Cardiac Rehabilitation outpatient Unit at Careggi University Hospital, were screened for eligibility. Moderate/severe cognitive impairment, disability in 2+ basic activities of daily living, musculoskeletal diseases, contraindication to Cardiopulmonary Exercise Test, and diseases with an expected survival < 6 months, were exclusion criteria. Participants attended a CR program, based on 5-day-per-week aerobic training sessions for 4 weeks.

RESULTS

We enrolled 253 post-ACS patients with a mean age 80.6 ± 4.4 years. After CR, 136 (56.2%) 77 (31.3%) patients obtained, respectively, at least a moderate (∆+5%) or an optimal (∆+15%) increase in VO₂peak. Baseline VO₂peak (- 1 ml/kg/min: OR 1.18; 95% CI 1.09-1.28), the number of training sessions (+1 session: OR 1.07; 95% CI 1.01-1.15), and mild-to-moderate baseline disability (yes vs. no: OR 0.22; 95% CI 0.01-0.57) were the predictors of VO₂peak changes.

CONCLUSIONS

A CR program started early after discharge from ACS produces a significant increase in exercise capacity in very old patients with mild-to-moderate post-acute physical impairment. Baseline VO₂peak, the number of training sessions, and the level of baseline disability are the independent predictors of improvement.

Aging is associated with cardiac autonomic nerve fiber depletion and reduced cardiac and circulating BDNF levels

BACKGROUND

Aging is a multifactorial process associated with an impairment of autonomic nervous system (ANS) function. Progressive ANS remodeling includes upregulation of expression of circulating catecholamines and depletion of cardiac autonomic nerve fibers, and it is responsible, in part, for the increased susceptibility to cardiac diseases observed in elderly subjects. Neurotrophic factors, such as brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), are involved in synaptogenesis and neurite outgrowth processes, supporting neuronal cell differentiation and maturation. However, whether and how these factors and their downstream signaling are involved in cardiac aging remains unclear. Here, we tested whether, in the aged heart, the overall extent of autonomic fibers is reduced, owing to lower production of trophic factors such as BDNF and NGF.

METHODS

In vivo, we used young (age: 3 months; n = 10) and old (age: 24 months; n = 11) male Fisher rats, whereas, we used human neuroblastoma (SH-SY5Y) cells in vitro.

RESULTS

Compared to the young rats, old rats displayed a marked reduction in the overall ANS fiber density, affecting both sympathetic and cholinergic compartments, as indicated by dopamine β-hydroxylase (dβh) and vesicular acetylcholine transporter (VaChT) immunohistochemical staining. In addition, a marked downregulation of GAP-43 and BDNF protein was observed in the left ventricular lysates of old rats compared to those of young rats. Interestingly, we did not find any significant difference in cardiac NGF levels between the young and old groups. To further explore the impact of aging on ANS fibers, we treated SH-SY5Y cells in vitro with serum obtained from young and old rats. Sera from both groups induced a remarkable increase in neuronal sprouting, as evidenced by a crystal violet assay. However, this effect was blunted in cells cultured with old rat serum and was accompanied by a marked reduction in GAP-43 and BDNF protein levels.

CONCLUSIONS

Our data indicate that physiological aging is associated with an impairment of ANS structure and function and that reduced BDNF levels are responsible, at least in part, for these phenomena.

Gender-specific issues in cardiac rehabilitation: do women with ischaemic heart disease need specially tailored programmes?

Ischaemic heart disease (IHD) has changed from a disease of middle-aged men in the late 1970s to a disease of elderly women in the 2000s. Most clinical studies during the past three decades have been conducted with men. Cardiac rehabilitation programmes were also developed with special regard to improving the rate of return to work in middle-aged men. The rehabilitation needs of older patients and women in particular have been largely neglected. The aim of this review is briefly to outline our present knowledge on gender issues in cardiac rehabilitation, and to specify barriers with regard to physical activities especially in (older) women. Coping with a cardiac event, women tend to minimize or play down the impact of their health situation and avoid burdening their social contacts. After a first cardiac event, women report greater psychological distress and lower self-efficacy and self-esteem. In addition, older age, lower exercise levels and reduced functional capacity or co-morbid conditions such as osteoporosis and urinary incontinence are barriers to physical activities in women with IHD. Recent studies on psychosocial intervention revealed less favourable results in women compared with men. These findings have not yet been well explained. This emphasizes our current lack of knowledge about the processes and determinants of successful psychosocial interventions in men and women with IHD. A large (European) trial on gender-specific coping styles, needs, and preferences of older women, and the effects of psychosocial intervention is proposed.

Cardiac rehabilitation improves the blood plasma properties of cardiac patients

Cardiac rehabilitation (CR) improves exercise tolerance and general function. However, its effects on blood plasma in cardiac patients remain uncertain. Our aim was to examine the effect of comprehensive CR on the oxidative stress parameters and antioxidant plasma status in patients with coronary artery disease (CAD) after cardiac interventions. Exercise-based rehabilitation was established as ergometer training, adjusted for individual patients' physical efficiency. Training was repeated three times a week for two months. The standard biochemical (total cholesterol, HDL, LDL, triglycerides and erythrocyte sedimentation rate) and metabolic parameters (peak oxygen uptake [VO₂] and peak workload) were determined. We assessed plasma viscosity, lipid peroxidation, carbonyl compounds levels, glutathione (GSH) and ascorbate (ASC) levels and the non-enzymatic antioxidant capacity of plasma in 12 patients with CAD before and after CR. Parameters were examined before exercise, immediately after exercise, and 1 h later. We also compared morphological and biochemical parameters of blood, as well as other parameters such as heart rate and blood pressure (resting and exercise), VO₂max and peak workload (W) before and after CR. Before CR, a significant decrease in GSH concentration was observed 1 h after exercise. Conversely, after CR, GSH, and ASC levels remained unchanged immediately after exercise. However, ASC increased after CR after exercise and 1 h later in comparison to before CR. There was a significant increase in ferric reduction ability of plasma immediately after exercise after CR, when compared with before CR. CR improved several blood biochemical parameters, peak VO₂, induced an increase in systolic blood pressure peak, and patients' peak workload. After CR, improvements were detected in oxidative stress parameters, except in the level of carbonyls. These changes may contribute to the increased functional heart capacity and better tolerance to exercise and functional capacity of the patients. These improvements could indicate better prognosis of future cardiac events and hospitalization and better quality of life.

Healthy aging and myocardium: A complicated process with various effects in cardiac structure and physiology

It is known that there is an ongoing increase in life expectancy worldwide, especially in the population older than 65years of age. Cardiac aging is characterized by a series of complex pathophysiological changes affecting myocardium at structural, cellular, molecular and functional levels. These changes make the aged myocardium more susceptible to stress, leading to a high prevalence of cardiovascular diseases (heart failure, atrial fibrillation, left ventricular hypertrophy, coronary artery disease) in the elderly population. The aging process is genetically programmed but modified by environmental influences, so that the rate of aging can vary widely among people. We summarized the entire data concerning all the multifactorial changes in aged myocardium and highlighting the recent evidence for the pathophysiological basis of cardiac aging. Keeping an eye on the clinical side, this review will explore the potential implications of the age-related changes in the clinical management and on novel therapeutic strategies potentially deriving from the scientific knowledge currently acquired on cardiac aging process.

β-adrenergic receptor responsiveness in aging heart and clinical implications

Elderly healthy individuals have a reduced exercise tolerance and a decreased left ventricle inotropic reserve related to increased vascular afterload, arterial-ventricular load mismatching, physical deconditioning and impaired autonomic regulation (the so called "β-adrenergic desensitization"). Adrenergic responsiveness is altered with aging and the age-related changes are limited to the β-adrenergic receptor density reduction and to the β-adrenoceptor-G-protein(s)-adenylyl cyclase system abnormalities, while the type and level of abnormalities change with species and tissues. Epidemiological studies have shown an high incidence and prevalence of heart failure in the elderly and a great body of evidence correlate the changes of β-adrenergic system with heart failure pathogenesis. In particular it is well known that: (a) levels of cathecolamines are directly correlated with mortality and functional status in heart failure, (b) β1-adrenergic receptor subtype is down-regulated in heart failure, (c) heart failure-dependent cardiac adrenergic responsiveness reduction is related to changes in G proteins activity. In this review we focus on the cardiovascular β-adrenergic changes involvement in the aging process and on similarities and differences between aging heart and heart failure.

Cardiac rehabilitation past, present and future: an overview

Cardiac Rehabilitation has evolved over the past decades from a simple monitoring for the safe return to physical activities to a multidisciplinary approach that focuses on patient education, individually tailored exercise training, modification of the risk factors and the overall well-being of the cardiac patients. It has been proven to be an effective tool for the care of the patients with heart disease. Recent research in cardiac rehabilitation has demonstrated that tremendous benefits can be derived from the optimal use of cardiac rehabilitation in patients with various cardiac pathologies including ischemic heart disease, heart failure and post heart surgery. The benefits of cardiac rehabilitation include mortality reduction, symptom relief, reduction in smoking and improved exercise tolerance, risk factors modification and the overall psychosocial wellbeing. Unfortunately, cardiac rehabilitation remains considerably underutilized mainly because of referral problems and poor enrollment. The development of alternate approaches and the use of transtelephonic and other means of monitoring and surveillance will help expand the utilization of cardiac rehabilitation.

Adrenergic signaling and oxidative stress: a role for sirtuins?

The adrenergic system plays a central role in stress signaling and stress is often associated with increased production of ROS. However, ROS overproduction generates oxidative stress, that occurs in response to several stressors. β-adrenergic signaling is markedly attenuated in conditions such as heart failure, with downregulation and desensitization of the receptors and their uncoupling from adenylyl cyclase. Transgenic activation of β2-adrenoceptor leads to elevation of NADPH oxidase activity, with greater ROS production and p38MAPK phosphorylation. Inhibition of NADPH oxidase or ROS significantly reduced the p38MAPK signaling cascade. Chronic β2-adrenoceptor activation is associated with greater cardiac dilatation and dysfunction, augmented pro-inflammatory and profibrotic signaling, while antioxidant treatment protected hearts against these abnormalities, indicating ROS production to be central to the detrimental signaling of β2-adrenoceptors. It has been demonstrated that sirtuins are involved in modulating the cellular stress response directly by deacetylation of some factors. Sirt1 increases cellular stress resistance, by an increased insulin sensitivity, a decreased circulating free fatty acids and insulin-like growth factor (IGF-1), an increased activity of AMPK, increased activity of PGC-1a, and increased mitochondrial number. Sirt1 acts by involving signaling molecules such P-I-3-kinase-Akt, MAPK and p38-MAPK-β. βAR stimulation antagonizes the protective effect of the AKT pathway through inhibiting induction of Hif-1α and Sirt1 genes, key elements in cell survival. More studies are needed to better clarify the involvement of sirtuins in the β-adrenergic response and, overall, to better define the mechanisms by which tools such as exercise training are able to counteract the oxidative stress, by both activation of sirtuins and inhibition of GRK2 in many cardiovascular conditions and can be used to prevent or treat diseases such as heart failure.

Adrenergic signaling and oxidative stress: a role for sirtuins?

The adrenergic system plays a central role in stress signaling and stress is often associated with increased production of ROS. However, ROS overproduction generates oxidative stress, that occurs in response to several stressors. β-adrenergic signaling is markedly attenuated in conditions such as heart failure, with downregulation and desensitization of the receptors and their uncoupling from adenylyl cyclase. Transgenic activation of β2-adrenoceptor leads to elevation of NADPH oxidase activity, with greater ROS production and p38MAPK phosphorylation. Inhibition of NADPH oxidase or ROS significantly reduced the p38MAPK signaling cascade. Chronic β2-adrenoceptor activation is associated with greater cardiac dilatation and dysfunction, augmented pro-inflammatory and profibrotic signaling, while antioxidant treatment protected hearts against these abnormalities, indicating ROS production to be central to the detrimental signaling of β2-adrenoceptors. It has been demonstrated that sirtuins are involved in modulating the cellular stress response directly by deacetylation of some factors. Sirt1 increases cellular stress resistance, by an increased insulin sensitivity, a decreased circulating free fatty acids and insulin-like growth factor (IGF-1), an increased activity of AMPK, increased activity of PGC-1a, and increased mitochondrial number. Sirt1 acts by involving signaling molecules such P-I-3-kinase-Akt, MAPK and p38-MAPK-β. βAR stimulation antagonizes the protective effect of the AKT pathway through inhibiting induction of Hif-1α and Sirt1 genes, key elements in cell survival. More studies are needed to better clarify the involvement of sirtuins in the β-adrenergic response and, overall, to better define the mechanisms by which tools such as exercise training are able to counteract the oxidative stress, by both activation of sirtuins and inhibition of GRK2 in many cardiovascular conditions and can be used to prevent or treat diseases such as heart failure.

Potential mechanisms linking atherosclerosis and increased cardiovascular risk in COPD: focus on Sirtuins

The development of atherosclerosis is a multi-step process, at least in part controlled by the vascular endothelium function. Observations in humans and experimental models of atherosclerosis have identified monocyte recruitment as an early event in atherogenesis. Chronic inflammation is associated with ageing and its related diseases (e.g., atherosclerosis and chronic obstructive pulmonary disease). Recently it has been discovered that Sirtuins (NAD⁺-dependent deacetylases) represent a pivotal regulator of longevity and health. They appear to have a prominent role in vascular biology and regulate aspects of age-dependent atherosclerosis. Many studies demonstrate that SIRT1 exhibits anti-inflammatory properties in vitro (e.g., fatty acid-induced inflammation), in vivo (e.g., atherosclerosis, sustainment of normal immune function in knock-out mice) and in clinical studies (e.g., patients with chronic obstructive pulmonary disease). Because of a significant reduction of SIRT1 in rodent lungs exposed to cigarette smoke and in lungs of patients with chronic obstructive pulmonary disease (COPD), activation of SIRT1 may be a potential target for chronic obstructive pulmonary disease therapy. We review the inflammatory mechanisms involved in COPD-CVD coexistence and the potential role of SIRT1 in the regulation of these systems.

An elderly-centered, personalized, physiotherapy program early after cardiac surgery

BACKGROUND

Early post-surgery in-hospital rehabilitation in elderly patients should be aimed at accelerating the recovery of the highest level of functional autonomy and reducing the hospital stay.

DESIGN

We designed a personalized physiotherapy program tailored to the frailty level of over-70-year-old patients soon after cardiac surgery. The aims of this study were (a) to validate our frailty-based approach for functional stratification of the patients, and (b) to assess the effect of the individualized program on independence and mobility, and compare it with our usual program.

METHODS

We followed 224 consecutive patients aged 70-87 years, who followed either the personalized (n= 150) or usual (n= 74) program. All patients underwent a comprehensive physical functioning evaluation at the baseline and at the end of hospitalization.

RESULTS

The frailty-based stratification was successful in identifying those patients at higher risk of falls, with heavy nursing needs, greater dependency, and poorer heath status perception. On discharge, both groups had significantly improved on all measures of independence and mobility, but most of these changes (nursing needs, mobility, balance, and muscle strength) were significantly greater (P < 0.05) in the intervention group. These patients also had a significantly shorter length of stay (17.5 ± 8 vs. 21 ± 4 days, P = 0.0002), and 91% of them could be discharged in a state of substantial independence.

CONCLUSION

An elderly-centered stratification based on functional frailty is useful to identify patients with more dependency and greater needs. A consequent personalized physiotherapy program designed to enhance independent mobility soon after cardiac surgery is safe and well accepted, and is more effective then usual physiotherapy.

Barriers to cardiac rehabilitation: DOES AGE MAKE A DIFFERENCE?

PURPOSE

To quantitatively investigate age differences in barriers to cardiac rehabilitation (CR) enrollment and participation.

METHODS

Cardiac outpatients (N = 1,273, mean age = 65.9 +/- 11.2) completed a mailed survey to discern barriers to CR enrollment and participation. Both enrollees and nonenrollees were asked to rate 18 CR barriers on a 5-point Likert scale.

RESULTS

Of the respondents, 535 (43%) reported participating in CR at 1 of 40 sites, with younger patients being more likely to participate (P = .002). Older age was positively related to total CR barriers (P < .001). Older patients more strongly endorsed the following CR barriers: already exercising at home (P = .001), confidence in ability to self-manage their condition (P = .003), perception of exercise as tiring or painful (P = .001), not knowing about CR (P = .001), lack of physician encouragement (P < .001), comorbidities (P < .001), and perception that CR would not improve their health (P < .001).

CONCLUSION

Given that the benefits of CR are achieved in older patients as well as the young, interventions to overcome these modifiable barriers to enrollment and participation are needed.