Gordon Blackburn

Effects of Exercise Training on Depressive Symptoms in Patients With Chronic Heart Failure: The HF-ACTION Randomized Trial

CONTEXT Depression is common in patients with cardiac disease, especially in patients with heart failure, and is associated with increased risk of adverse health outcomes. Some evidence suggests that aerobic exercise may reduce depressive symptoms, but to our knowledge the effects of exercise on depression in patients with heart failure have not been evaluated. OBJECTIVE To determine whether exercise training will result in greater improvements in depressive symptoms compared with usual care among patients with heart failure. DESIGN, SETTING, AND PARTICIPANTS Multicenter, randomized controlled trial involving 2322 stable patients treated for heart failure at 82 medical clinical centers in the United States, Canada, and France. Patients who had a left ventricular ejection fraction of 35% or lower, had New York Heart Association class I to IV heart failure, and had completed the Beck Depression Inventory II (BDI-II) score were randomized (1:1) between April 2003 and February 2007. Depressive scores ranged from 0 to 59; scores of 14 or higher are considered clinically significant. INTERVENTIONS Participants were randomized either to supervised aerobic exercise (goal of 90 min/wk for months 1-3 followed by home exercise with a goal of ≥120 min/wk for months 4-12) or to education and usual guideline-based heart failure care. MAIN OUTCOME MEASURES Composite of death or hospitalization due to any cause and scores on the BDI-II at months 3 and 12. RESULTS Over a median follow-up period of 30 months, 789 patients (68%) died or were hospitalized in the usual care group compared with 759 (66%) in the aerobic exercise group (hazard ratio [HR], 0.89; 95% CI, 0.81 to 0.99; P = .03). The median BDI-II score at study entry was 8, with 28% of the sample having BDI-II scores of 14 or higher. Compared with usual care, aerobic exercise resulted in lower mean BDI-II scores at 3 months (aerobic exercise, 8.95; 95% CI, 8.61 to 9.29 vs usual care, 9.70; 95% CI, 9.34 to 10.06; difference, -0.76; 95% CI,-1.22 to -0.29; P = .002) and at 12 months (aerobic exercise, 8.86; 95% CI, 8.67 to 9.24 vs usual care, 9.54; 95% CI, 9.15 to 9.92; difference, -0.68; 95% CI, -1.20 to -0.16; P = .01). CONCLUSIONS Compared with guideline-based usual care, exercise training resulted in a modest reduction in depressive symptoms, although the clinical significance of this improvement is unknown. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00047437.

Women's patterns of exercise following cardiac rehabilitation.

BACKGROUND Studies of long-term exercise maintenance after an acute cardiac event have been conducted almost exclusively with men, and the findings cannot be generalized to women. OBJECTIVES The aim of this study was to identify womens exercise patterns and adherence to recommended exercise maintenance after a cardiac rehabilitation (CR) program. METHOD Forty women who had a myocardial infarction or had undergone coronary artery bypass graft (CABG) surgery were recruited through convenience sampling immediately after completion of a phase II CR program. Exercise frequency, duration, and intensity were measured using wristwatch heart rate (HR) monitors during exercise for 3 months. RESULTS Results indicated that 12 of 40 (30%) women exercised five times or fewer during the 3-month study period. Only 11 women (27.5%) exercised three or more times per week. Women exercised an average of 5.2 sessions within their target HR during the entire study period. Maintenance of exercise dropped consistently during the course of the study. Although 83% of the participating women started exercising during the first month, after 1 month one third of the participants had stopped exercising. During the last week of the study, only 50% of the women were still exercising. CONCLUSIONS These findings indicate the women are exercising well below the recommended guidelines for exercise after acute cardiac events.

Cardiac Rehabilitation Participation Patterns in a Large, Tertiary Care Center: Evidence for Selection Bias

BACKGROUND Clinical practice guidelines have been published for cardiac rehabilitation, directing programs to address secondary risk-reduction issues. The role of risk factor profiles in the referral of patients to cardiac rehabilitation programs has not been evaluated. METHODS Patients from the Cardiovascular Information Registry at the Cleveland Clinic Foundation (CCF) who entered the CCF hospital-based cardiac rehabilitation program (n = 371) were compared with those who did not participate in the CCF program (n = 2960) with respect to gender, demographics, and risk factor profile for CAD. A random subset of those who did not participate in the CCF program (n = 100) was interviewed by phone to determine participation patterns in other rehabilitation programs. RESULTS Only 11% of patients participated in CCF-based program. Standard risk factors were similar between participants and nonparticipants. Rehabilitation patients were younger (63 +/- 10 versus 66 +/- 10, P < 0.01) and as a group had better left ventricular function (moderate-severe left ventricle: 16% versus 23%, P < 0.01) than nonparticipants. Women were underrepresented in the CCF rehabilitation population (20% versus 30%, P < 0.01). Of the phone survey sample, 21% of patients entered other community-based rehabilitation programs. Similar trends with respect to risk factors, younger age, and better left ventricular function were noted for the community subset. However, women accounted for a greater percentage of the participants in the community programs than the CCF-based program (42.8% versus 19.7%, P < 0.03). CONCLUSIONS Conclusions based on institution-specific programs likely underestimate overall participation in cardiac rehabilitation. Traditional risk factors apparently are not considered when referring patients to cardiac rehabilitation programs. Younger patients with lower mortality risks preferentially participate in rehabilitation programs. Women are more likely to participate in community-based programs. Overall use of cardiac rehabilitation programs remains low.

Modest Increase in Peak VO2 Is Related to Better Clinical Outcomes in Chronic Heart Failure Patients Results From Heart Failure and a Controlled Trial to Investigate Outcomes of Exercise Training

Background—The prognostic ability of a single measurement of peak oxygen uptake (VO2) is well established in patients with chronic heart failure. The relation between a change in peak VO2 and clinical outcomes is not well defined. Methods and Results—This investigation determined whether an increase in peak VO2 was associated with a lower risk of the primary end point of time to all-cause mortality or all-cause hospitalization and 3 secondary end points. In Heart Failure and a Controlled Trial to Investigate Outcomes of Exercise Training, an exercise training trial for patients with systolic heart failure, cardiopulmonary exercise tests were performed at baseline and ≈3 months later in 1620 participants. Median peak VO2 in the combined sample increased from 15.0 (11.9–18.0 Q1–Q3) to 15.4 (12.3–18.7 Q1–Q3) mL·kg−1·min−1. Every 6% increase in peak VO2, adjusted for other significant predictors, was associated with a 5% lower risk of the primary end point (hazard ratio=0.95; CI=0.93–0.98; P<0.001); a 4% lower risk of the secondary end point of time to cardiovascular mortality or cardiovascular hospitalization (hazard ratio=0.96; CI=0.94–0.99; P<0.001); an 8% lower risk of cardiovascular mortality or heart failure hospitalization (hazard ratio=0.92; CI=0.88–0.96; P<0.001); and a 7% lower all-cause mortality (hazard ratio=0.93; CI=0.90–0.97; P<0.001). Conclusions—Among patients with chronic systolic heart failure, a modest increase in peak VO2 over 3 months was associated with a more favorable outcome. Monitoring the change in peak VO2 for such patients may have benefit in assessing prognosis. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00047437.

Accuracy of Wrist-Worn Heart Rate Monitors

Accuracy of Wrist-Worn Heart Rate Monitors Wrist-worn fitness and heart rate (HR) monitors are popular.1,2 While the accuracy of chest strap, electrode-based HR monitors has been confirmed,3,4 the accuracy of wrist-worn, optically based HR monitors is uncertain.5,6 Assessment of the monitors’ accuracy is important for individuals who use them to guide their physical activity and for physicians to whom these individuals report HR readings. The objective of this study was to assess the accuracy of 4 popular wrist-worn HR monitors under conditions of varying physical exertion.

Variable Accuracy of Wearable Heart Rate Monitors during Aerobic Exercise.

Purpose Athletes and members of the public increasingly rely on wearable HR monitors to guide physical activity and training. The accuracy of newer, optically based monitors is unconfirmed. We sought to assess the accuracy of five optically based HR monitors during various types of aerobic exercise. Methods Fifty healthy adult volunteers (mean ± SD age = 38 ± 12 yr, 54% female) completed exercise protocols on a treadmill, a stationary bicycle, and an elliptical trainer (±arm movement). Each participant underwent HR monitoring with an electrocardiogaphic chest strap monitor (Polar H7), forearm monitor (Scosche Rhythm+), and two randomly assigned wrist-worn HR monitors (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, and TomTom Spark Cardio), one on each wrist. For each exercise type, HR was recorded at rest, light, moderate, and vigorous intensity. Agreement between HR measurements was assessed using Lins concordance correlation coefficient (rc). Results Across all exercise conditions, the chest strap monitor (Polar H7) had the best agreement with ECG (rc = 0.996) followed by the Apple Watch (rc = 0.92), the TomTom Spark (rc = 0.83), and the Garmin Forerunner (rc = 0.81). Scosche Rhythm+ and Fitbit Blaze were less accurate (rc = 0.75 and rc = 0.67, respectively). On treadmill, all devices performed well (rc = 0.88–0.93) except the Fitbit Blaze (rc = 0.76). While bicycling, only the Garmin, Apple Watch, and Scosche Rhythm+ had acceptable agreement (rc > 0.80). On the elliptical trainer without arm levers, only the Apple Watch was accurate (rc = 0.94). None of the devices was accurate during elliptical trainer use with arm levers (all rc < 0.80). Conclusion The accuracy of wearable, optically based HR monitors varies with exercise type and is greatest on the treadmill and lowest on elliptical trainer. Electrode-containing chest monitors should be used when accurate HR measurement is imperative.

Exercise Performance and Chronotropic Response in Heart Failure Patients With Implantable Left Ventricular Assist Devices

During metabolic stress testing, 9 of 20 patients with left ventricular assist devices exhibited a lag in peak device rate by < or = 85% of peak native heart rate (group I), with peak device rates of 118 +/- 9 beats/min compared with group II, in which peak device rate nearly equaled peak native rates. Peak systolic blood pressure was significantly greater in group II than group I, but there was no significant difference in peak oxygen consumption, anaerobic threshold, or peak flows.

Asymmetrical pedaling patterns in Parkinson's disease patients.

BACKGROUND Approximately 1.5 million Americans are affected by Parkinsons disease (Deponti et al., 2013) which includes the symptoms of postural instability and gait dysfunction. Currently, clinical evaluations of postural instability and gait dysfunction consist of a subjective rater assessment of gait patterns using items from the Unified Parkinsons Disease Rating Scale, and assessments can be insensitive to the effectiveness of medical interventions. Current research suggests the importance of cycling for Parkinsons disease patients, and while Parkinsons gait has been evaluated in previous studies, little is known about lower extremity control during cycling. The purpose of this study is to examine the lower extremity coordination patterns of Parkinsons patients during cycling. METHODS Twenty five participants, ages 44-72, with a clinical diagnosis of idiopathic Parkinsons disease participated in an exercise test on a cycle ergometer that was equipped with pedal force measurements. Crank torque, crank angle and power produced by right and left leg were measured throughout the test to calculate Symmetry Index at three stages of exercise (20 W, 60 W, maximum performance). FINDINGS Decreases in Symmetry Index were observed for average power output in Parkinsons patients as workload increased. Maximum power Symmetry Index showed a significant difference in symmetry between performance at both the 20 W and 60 W stage and the maximal resistance stage. Minimum power Symmetry Index did not show significant differences across the stages of the test. While lower extremity asymmetries were present in Parkinsons patients during pedaling, these asymmetries did not correlate to postural instability and gait dysfunction Unified Parkinsons Disease Rating Scale scores. INTERPRETATION This pedaling analysis allows for a more sensitive measure of lower extremity function than the Unified Parkinsons Disease Rating Scale and may help to provide unique insight into current and future lower extremity function.

VARIABLE ACCURACY OF COMMERCIALLY AVAILABLE WEARABLE HEART RATE MONITORS

Background: The accuracy of wrist-worn heart rate (HR) monitors is unconfirmed. We assessed accuracy of 5 wrist-worn HR monitors (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, TomTom Spark Cardio, Scosche Rhythm+) during various types of exercise. Methods: Fifty volunteers completed exercise

Exercise in the Prevention of Coronary Artery Disease

Coronary artery disease (CAD) is a chronic, multifactor disease that has powerful contributing genetic components as well as strong lifestyle components that increase the risk for the development and progression of the disease. Risk factors for CAD have been historically divided into nonmodifiable, primary modifiable, and secondary modifiable factors. The primary focus of medicine has been on the treatment of established CAD, and preventive efforts have more aggressively addressed areas in which direct pharmacological intervention is available (1) (see Table 1). This is especially evident with respect to hypertension, hyperlipidemia, and antiplatelet aggregation therapy.