Peter H. Brubaker

Exercise Training in Older Patients with Heart Failure and Preserved Ejection Fraction: A Randomized, Controlled, Single-Blind Trial

Background—Heart failure (HF) with preserved left ventricular ejection fraction (HFPEF) is the most common form of HF in the older population. Exercise intolerance is the primary chronic symptom in patients with HFPEF and is a strong determinant of their reduced quality of life (QOL). Exercise training (ET) improves exercise intolerance and QOL in patients with HF with reduced ejection fraction (EF). However, the effect of ET in HFPEF has not been examined in a randomized controlled trial. Methods and Results—This 16-week investigation was a randomized, attention-controlled, single-blind study of medically supervised ET (3 days per week) on exercise intolerance and QOL in 53 elderly patients (mean age, 70±6 years; range, 60 to 82 years; women, 46) with isolated HFPEF (EF ≥50% and no significant coronary, valvular, or pulmonary disease). Attention controls received biweekly follow-up telephone calls. Forty-six patients completed the study (24 ET, 22 controls). Attendance at exercise sessions in the ET group was excellent (88%; range, 64% to 100%). There were no trial-related adverse events. The primary outcome of peak exercise oxygen uptake increased significantly in the ET group compared to the control group (13.8±2.5 to 16.1±2.6 mL/kg per minute [change, 2.3±2.2 mL/kg per minute] versus 12.8±2.6 to 12.5±3.4 mL/kg per minute [change, −0.3±2.1 mL/kg per minute]; P=0.0002). There were significant improvements in peak power output, exercise time, 6-minute walk distance, and ventilatory anaerobic threshold (all P<0.002). There was improvement in the physical QOL score (P=0.03) but not in the total score (P=0.11). Conclusions—ET improves peak and submaximal exercise capacity in older patients with HFPEF. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01113840.

Determinants of Exercise Intolerance in Elderly Heart Failure Patients With Preserved Ejection Fraction

OBJECTIVES The purpose of this study was to determine the mechanisms responsible for reduced aerobic capacity (peak Vo(2)) in patients with heart failure with preserved ejection fraction (HFPEF). BACKGROUND HFPEF is the predominant form of heart failure in older persons. Exercise intolerance is the primary symptom among patients with HFPEF and a major determinant of reduced quality of life. In contrast to patients with heart failure and reduced ejection fraction, the mechanism of exercise intolerance in HFPEF is less well understood. METHODS Left ventricular volumes (2-dimensional echocardiography), cardiac output, Vo(2), and calculated arterial-venous oxygen content difference (A-Vo(2) Diff) were measured at rest and during incremental, exhaustive upright cycle exercise in 48 HFPEF patients (age 69 ± 6 years) and 25 healthy age-matched controls. RESULTS In HFPEF patients compared with healthy controls, Vo(2) was reduced at peak exercise (14.3 ± 0.5 ml·kg·min(-1) vs. 20.4 ± 0.6 ml·kg·min(-1); p < 0.0001) and was associated with a reduced peak cardiac output (6.3 ± 0.2 l·min(-1) vs. 7.6 ± 0.2 l·min(-1); p < 0.0001) and A-Vo(2) Diff (17 ± 0.4 ml·dl(-1) vs. 19 ± 0.4 ml·dl(-1), p < 0.0007). The strongest independent predictor of peak Vo(2) was the change in A-Vo(2) Diff from rest to peak exercise (A-Vo(2) Diff reserve) for both HFPEF patients (partial correlate, 0.58; standardized β coefficient, 0.66; p = 0.0002) and healthy controls (partial correlate, 0.61; standardized β coefficient, 0.41; p = 0.005). CONCLUSIONS Both reduced cardiac output and A-Vo(2) Diff contribute significantly to the severe exercise intolerance in elderly HFPEF patients. The finding that A-Vo(2) Diff reserve is an independent predictor of peak Vo(2) suggests that peripheral, noncardiac factors are important contributors to exercise intolerance in these patients.

Chronotropic Incompetence Causes, Consequences, and Management

Chronotropic incompetence (CI), broadly defined as the inability of the heart to increase its rate commensurate with increased activity or demand, is common in patients with cardiovascular disease, produces exercise intolerance that impairs quality of life, and is an independent predictor of major adverse cardiovascular events and overall mortality. However, the importance of CI is underappreciated, and CI is often overlooked in clinical practice. This may be due in part to multiple definitions, the confounding effects of aging and medications, and the need for formal exercise testing for definitive diagnosis. This review discusses the definition, mechanisms, diagnosis, and treatment of CI, with particular emphasis on its prominent role in heart failure (HF). CI is common and can be diagnosed by objective, widely available, inexpensive methods; it is potentially treatable, and its management can lead to significant improvements in exercise tolerance and quality of life. The ability to perform physical work is an important determinant of quality of life,1 and is enabled by an increase in oxygen uptake (Vo2).2 During maximal aerobic exercise in healthy humans, Vo2 increases approximately 4-fold.2 This is achieved by a 2.2-fold increase in heart rate (HR), a 0.3-fold increase in stroke volume, and a 1.5-fold increase in arteriovenous oxygen difference.2 Thus, the increase in HR is the strongest contributor to the ability to perform sustained aerobic exercise.3 It is therefore not surprising that CI can be the primary cause of or a significant contributor to severe, symptomatic exercise intolerance. HR at any moment in time reflects the dynamic balance between the sympathetic and parasympathetic divisions of the autonomic nervous system. Although the intrinsic rate of the sinoatrial node is approximately 100 beats per minute (bpm), resting HR in humans is generally much lower (60 to 80 …

The Importance of Cardiorespiratory Fitness in the United States: The Need for a National Registry A Policy Statement From the American Heart Association

The recent 2012 update of the Heart Disease and Stroke Statistics from the American Heart Association (AHA) emphasizes the continuing burden of cardiovascular disease (CVD) in the United States, with a prevalence of CVD nearing 40% in those approaching 60 years of age and exceeding 70% in older ages.1 Direct and indirect costs of CVD in the United States exceeded

Effect of endurance training on the determinants of peak exercise oxygen consumption in elderly patients with stable compensated heart failure and preserved ejection fraction.

300 billion in 2008, and the projected total costs of CVD in 2015 and 2030 are more than

Older adults with chronic disease: benefits of group-mediated counseling in the promotion of physically active lifestyles.

500 billion and nearly

Physical Activity, Fitness, and Health: Consensus Statement

1200 billion, respectively.2 Recently, the AHA developed year 2020 impact goals to achieve ideal cardiovascular health, which is influenced greatly by key health behaviors of being physically active, maintaining appropriate dietary habits, and not smoking.3 The obesity epidemic in the United States has been a substantial contributor to the CVD burden, with current estimates of obesity prevalence being ≈20% in US children and adolescents and >33% in adults 20 to 74 years of age. It is well accepted that for most people, obesity is a direct outcome of an energy-rich diet, lack of sufficient physical activity (PA), or both. Another consequence of both obesity and insufficient PA is a reduction in cardiorespiratory (or aerobic) fitness (CRF) levels. Collectively, this evidence emphasizes that an individual’s health behaviors have a major role in the prevention of CVD, which is of critical importance in the United States and worldwide from a medical and economic perspective. Increasing attention is being given to the importance of PA and physical fitness (PF), both muscular fitness and especially CRF, for decreasing chronic diseases, promoting overall cardiovascular and general health, improving quality of life, and delaying CVD and mortality in the US population.4,5 Clearly, PF and CRF in particular are an underpinning for academic achievement, job productivity, and overall maintenance …

Effect of Caloric Restriction or Aerobic Exercise Training on Peak Oxygen Consumption and Quality of Life in Obese Older Patients With Heart Failure With Preserved Ejection Fraction: A Randomized Clinical Trial

OBJECTIVES The purpose of this study was to evaluate the mechanisms for improved exercise capacity after endurance exercise training (ET) in elderly patients with heart failure and preserved ejection fraction (HFPEF). BACKGROUND Exercise intolerance, measured objectively by reduced peak oxygen consumption (VO(2)), is the primary chronic symptom in HFPEF and is improved by ET. However, the mechanisms are unknown. METHODS Forty stable, compensated HFPEF outpatients (mean age 69 ± 6 years) were examined at baseline and after 4 months of ET (n = 22) or attention control (n = 18). The VO(2) and its determinants were assessed during rest and peak upright cycle exercise. RESULTS After ET, peak VO(2) in those patients was higher than in control patients (16.3 ± 2.6 ml/kg/min vs. 13.1 ± 3.4 ml/kg/min; p = 0.002). That was associated with higher peak heart rate (139 ± 16 beats/min vs. 131 ± 20 beats/min; p = 0.03), but no difference in peak end-diastolic volume (77 ± 18 ml vs. 77 ± 17 ml; p = 0.51), stroke volume (48 ± 9 ml vs. 46 ± 9 ml; p = 0.83), or cardiac output (6.6 ± 1.3 l/min vs. 5.9 ± 1.5 l/min; p = 0.32). However, estimated peak arterial-venous oxygen difference was significantly higher in ET patients (19.8 ± 4.0 ml/dl vs. 17.3 ± 3.7 ml/dl; p = 0.03). The effect of ET on cardiac output was responsible for only 16% of the improvement in peak VO(2). CONCLUSIONS In elderly stable compensated HFPEF patients, peak arterial-venous oxygen difference was higher after ET and was the primary contributor to improved peak VO(2). This finding suggests that peripheral mechanisms (improved microvascular and/or skeletal muscle function) contribute to the improved exercise capacity after ET in HFPEF. (Prospective Aerobic Reconditioning Intervention Study [PARIS]; NCT01113840).

Translating Weight Loss and Physical Activity Programs Into the Community to Preserve Mobility in Older, Obese Adults in Poor Cardiovascular Health

In this 12-month trial standard exercise training was compared with a group-mediated cognitive-behavioral (GMCB) intervention with respect to effects on long-term adherence and change in physical function of older adults who were either at risk for or had cardiovascular disease. Participants (147 older men and women) were randomized to the 2 treatments. Outcomes included self-reportedphysical activity, fitness, and self-efficacy. The GMCB treatment produced greater improvements on all outcomes than did standard exercise therapy. Regardless of treatment assignment, men had more favorable change on the study outcomes than did women. Analysis of a self-regulatory process measure in the GMCB group revealed that change in barriers efficacy was related to change in physical activity and fitness. Results suggest that teaching older adults to integrate physical activity into their lives via GMCB leads to better long-term outcomes than standardized exercise therapy.

Relation of aortic distensibility determined by magnetic resonance imaging in patients ≥60 years of age to systolic heart failure and exercise capacity

Physical activity, fitness and health - the model and key concepts assessing the level and quality of evidence assessment of physical activity, fitness and health physical activity, fitness and health - status and determinants human adaptation to acute and chronic physical activity physical activity and fitness in disease physical activity and fitness across the life cycle risks of activity versus inactivity dose-response issues other considerations.