Relationship Between Exercise Workload During Cardiac Rehabilitation and Outcomes in Patients With Coronary Heart Disease

Among Patients Taking Beta-Adrenergic Blockade Therapy, Use Measured (Not Predicted) Maximal Heart Rate to Calculate a Target Heart Rate for Cardiac Rehabilitation

PURPOSE

Among patients in cardiac rehabilitation (CR) on beta-adrenergic blockade (βB) therapy, this study describes the frequency for which target heart rate (THR) values computed using a predicted maximal heart rate (HR max ), correspond to a THR computed using a measured HR max in the guideline-based heart rate reserve (HR reserve ) method.

METHODS

Before CR, patients completed a cardiopulmonary exercise test to measure HR max , with the data used to determine THR via the HR reserve method. Additionally, predicted HR max was computed for all patients using the 220 - age equation and two disease-specific equations, with the predicted values used to calculate THR via the straight percent and HR reserve methods. The THR was also computed using resting heart rate (HR) +20 and +30 bpm.

RESULTS

Mean predicted HR max using the 220 - age equation (161 ± 11 bpm) and the disease-specific equations (123 ± 9 bpm) differed ( P < .001) from measured HR max (133 ± 21 bpm). Also, THR computed using predicted HR max resulted in values that were infrequently within the guideline-based HR reserve range calculated using measured HR max . Specifically, 0 to ≤61% of patients would have had an exercise training HR that fell within the guideline-based range of 50-80% of measured HR reserve . Use of standing resting HR +20 or +30 bpm would have resulted in 100% and 48%, respectively, of patients exercising below 50% of HR reserve .

CONCLUSIONS

A THR computed using either predicted HR max or resting HR +20 or +30 bpm seldom results in a prescribed exercise intensity that is consistent with guideline recommendations for patients in CR.

Cardiac Rehabilitation Reduces 2-Year Mortality After Coronary Artery Bypass Grafting

BACKGROUND

Cardiac rehabilitation (CR) is a supervised outpatient exercise and risk reduction program offered to patients who have undergone coronary revascularization procedures. Multiple professional societal guidelines support the use of CR after coronary artery bypass grafting (CABG) based on studies in combined percutaneous coronary intervention and CABG populations with surrogate outcomes. This statewide analysis of patients undergoing CABG evaluated the relationship between CR use and long-term mortality.

METHODS

Medicare fee-for-service claims were linked to surgical data for patients discharged alive after isolated CABG from January 1, 2015, through September 30, 2019. Outpatient facility claims were used to identify any CR use within 1 year of discharge. Death within 2 years of discharge was the primary outcome. Mixed-effects logistic regression was used to predict CR use, adjusting for a variety of comorbidities. Unadjusted and inverse probability treatment weighting (IPTW) were used to compare 2-year mortality among CR users vs nonusers.

RESULTS

A total of 3848 of 6412 patients (60.0%) were enrolled in CR for an average of 23.2 (SD, 12.0) sessions, with 770 of 6412 (12.0%) completing all recommended 36 sessions. Logistic regression identified increasing age, discharge to home (vs extended care facility), and shorter length of stay as predictors of postdischarge CR use (P < .05). Unadjusted and IPTW analyses showed significant reduction in 2-year mortality in CR users compared with CR nonusers (unadjusted: 9.4% reduction; 95% CI, 10.8%-7.9%; P < .001; IPTW: -4.8% reduction; 95% CI, 6.0%-3.5%; P < .001).

CONCLUSIONS

These data suggest that CR use is associated with lower 2-year mortality. Future quality initiatives should consider identifying and addressing root causes of poor CR enrollment and completion.

Effects of Exercise Testing and Cardiac Rehabilitation in Patients with Coronary Heart Disease on Fear and Self-Efficacy of Exercise: A Pilot Study

BACKGROUND

Exercise fear and low exercise self-efficacy are common in patients attending cardiac rehabilitation (CR). This study tested whether exercise prescription methods influence exercise fear and exercise self-efficacy. We hypothesized that the use of graded exercise testing (GXT) with a target heart rate range exercise prescription, relative to standard exercise prescription using rating of perceived exertion (RPE), would produce greater reductions in exercise fear and increase self-efficacy during CR.

METHOD

Patients in CR (N = 32) were randomized to an exercise prescription using either RPE or a target heart rate range. Exercise fear and self-efficacy were assessed with questionnaires at three time points: baseline; after the GXT in target heart rate range group; and at session 6 for the RPE group and CR completion. Items were scored on a five-point Likert-type scale with higher mean scores reflecting higher fear of exercise and higher self-efficacy. To analyze mean differences, a mixed effects analysis was run.

RESULTS

There were no significant changes in exercise self-efficacy between baseline and discharge from CR; these were not statistically significant (mean differences baseline - 0.63; end - 0.27 (p = 0.13)). Similarly, there was no change in fear between groups (baseline 0.30; end 0.51 (p = 0.37)).

CONCLUSION

Patients in the RPE and target heart rate groups had non-significant changes in exercise self-efficacy over the course of CR. Contrary to our hypothesis, the use of GXT and target heart rate range did not reduce fear, and we noted sustained or increases in fear of exercise among patients with elevated baseline fear. A more targeted psychological intervention seems warranted to reduce exercise fear and self-efficacy in CR.

Evaluating the Feasibility of a Statewide Collaboration to Improve Cardiac Rehabilitation Participation: THE MICHIGAN CARDIAC REHAB NETWORK

PURPOSE

Regional quality improvement collaboratives may provide one solution to improving cardiac rehabilitation (CR) participation through performance benchmarking and provider engagement. The objective of this study was to evaluate the feasibility of the Michigan Cardiac Rehab Network to improve CR participation.

METHODS

Multipayer claims data from the Michigan Value Collaborative were used to identify hospitals and CR facilities and assemble a multidisciplinary advisory group. Univariate analyses described participating hospital characteristics and hospital-level rates of CR performance across eligible conditions including enrollment within 1 yr, mean days to first CR visit, and mean number of CR visits within 1 yr. Three diverse CR facilities were chosen for virtual site visits to identify areas of success and barriers to improvement.

RESULTS

A total of 95 hospitals and 84 CR facilities were identified, with 48 hospitals (51%) providing interventional cardiology services and 33 (35%) providing cardiac surgical services. A 17-member multidisciplinary advisory group was assembled representing 13 institutions and diverse roles. Statewide CR enrollment across eligible admissions was 33.4%, with wide variation in CR performance measures across participating hospitals and eligible admissions. Virtual site visits revealed individual successes in improving CR participation but a variety of barriers to participation related to referrals, capacity and staffing constraints, and geographic and financial barriers.

CONCLUSIONS

This study demonstrated the feasibility of creating a statewide collaboration of hospitals and CR facilities centered around the goal of equitably improving CR enrollment for all eligible patients in Michigan that is supported by a multidisciplinary advisory group and performance benchmarking.

Comparison of Ratings of Perceived Exertion and Target Heart Rate-Based Exercise Prescription in Cardiac Rehabilitation: A RANDOMIZED CONTROLLED PILOT STUDY

PURPOSE

Although ratings of perceived exertion (RPE) are widely used to guide exercise intensity in cardiac rehabilitation (CR), it is unclear whether target heart rate ranges (THRRs) can be implemented in CR programs that predominantly use RPE and what impact this has on changes in exercise capacity.

METHODS

We conducted a three-group pilot randomized control trial (#NCT03925493) comparing RPE of 3-4 on the 10-point modified Borg scale, 60-80% of heart rate reserve (HRR) with heart rate (HR) monitored by telemetry, or 60-80% of HRR with a personal HR monitor (HRM) for high-fidelity adherence to THRR. Primary outcomes were protocol fidelity and feasibility. Secondary outcomes included exercise HR, RPE, and changes in functional exercise capacity.

RESULTS

Of 48 participants randomized, four patients dropped out, 20 stopped prematurely (COVID-19 pandemic), and 24 completed the protocol. Adherence to THRR was high regardless of HRM, and patients attended a median (IQR) of 33 (23, 36) sessions with no difference between groups. After randomization, HR increased by 1 ± 6, 6 ± 5, and 10 ± 9 bpm ( P = .02); RPE (average score 3.0 ± 0.05) was unchanged, and functional exercise capacity increased by 1.0 ± 1.0, 1.9 ± 1.5, 2.0 ± 1.3 workload METs (effect size between groups, ηp2 = 0.11, P = .20) for the RPE, THRR, and THRR + HRM groups, respectively.

CONCLUSIONS

We successfully implemented THRR in an all-RPE CR program without needing an HRM. Patients randomized to THRR had higher exercise HR but similar RPE ratings. The THRR may be preferable to RPE in CR populations for cardiorespiratory fitness gains, but this needs confirmation in an adequately powered trial.

Exercise Prescription Methods and Attitudes in Cardiac Rehabilitation: A NATIONAL SURVEY

PURPOSE

High-quality exercise training improves outcomes in cardiac rehabilitation (CR), but little is known about how most programs prescribe exercise. Thus, the aim was to describe how current CR programs prescribe exercise.

METHODS

We conducted a 33-item anonymous survey of CR program directors registered with the American Association of Cardiovascular and Pulmonary Rehabilitation. We assessed the time, mode, and intensity of exercise prescribed, as well as attitudes about maximal exercise testing and exercise prescription. Results were summarized using descriptive statistics. Open-ended responses were coded and quantitated thematically.

RESULTS

Of 1470 program directors, 246 (16.7%) completed the survey. In a typical session of CR, a median of 5, 35, 10, and 5 min was spent on warm-up, aerobic exercise, resistance training, and cooldown, respectively. The primary aerobic modality was the treadmill (55%) or seated dual-action step machine (40%). Maximal exercise testing and high-intensity interval training (HIIT) were infrequently reported (17 and 8% of patients, respectively). The most common method to prescribe exercise intensity was ratings of perceived exertion followed by resting heart rate +20-30 bpm, although 55 unique formulas for establishing a target heart rate or range (THRR) were reported. Moreover, variation in exercise prescription between staff members in the same program was reported in 40% of programs. Program directors reported both strongly favorable and unfavorable opinions toward maximal exercise testing, HIIT, and use of THRR.

CONCLUSIONS

Cardiac rehabilitation program directors reported generally consistent exercise time and modes, but widely divergent methods and opinions toward prescribing exercise intensity. Our results suggest a need to better study and standardize exercise intensity in CR.

Relation of Exercise Capacity to Incident Heart Failure Among Men and Women With Coronary Heart Disease (from the Henry Ford Exercise Testing [FIT] Project)

Exercise capacity (EC) is inversely related to the risk of cardiovascular disease and incident heart failure (HF) in healthy subjects. However, there are no present studies that exclusively evaluate EC and the risk of incident HF in patients with known coronary heart disease (CHD). We aimed to determine the relation between EC and incident HF in patients with an established clinical diagnosis of CHD. We retrospectively identified 8,387 patients (age 61 ± 12 years; 30% women; 33% non-White) with a history of myocardial infarction (MI) or coronary revascularization procedure and no history of HF at the time of a clinically indicated exercise stress test completed between 1991 and 2009. EC was quantified in metabolic equivalents of task (METs) estimated from treadmill testing. Incident HF was identified through June 2010 from administrative databases based on ≥3 encounters with International Classification of Diseases, Ninth Revision 428.x. Cox regression analysis was used to evaluate the risk of incident HF associated with METs. Covariates included age; gender; race; hypertension, diabetes, hyperlipidemia, smoking, and MI; medications for CHD and lung diseases; and clinical indication for treadmill testing. During a median follow-up of 8.2 years (interquartile range 4.7 to 12.4 years) after the exercise test, 23% of the cohort experienced a new HF diagnosis. Lower EC categories were associated with higher HF incidence compared with METs ≥12, with nearly fourfold greater adjusted risk among patients with METs <6. Per unit increase in METs of EC was associated with a 12% lower adjusted risk for HF. There was no significant interaction based on race (p = 0.06), gender (p = 0.88), age ≤61 years (p = 0.60), history of MI (p = 0.31), or diabetes (p = 0.38). This study reveals that among men and women with CHD and no history of HF, EC is independently and inversely related to the risk of future HF.

Relation of a Maximal Exercise Test to Change in Exercise Tolerance During Cardiac Rehabilitation

The purpose of this study was to test the hypothesis that an individualized exercise training target heart rate (HR) based on a maximal graded exercise test (GXT) is associated with greater improvements in exercise tolerance during cardiac rehabilitation (CR) compared with no GXT. In this retrospective study, we identified patients who completed 9 to 36 visits of CR between 2001 and 2016, with a length of stay ≤18 weeks and a visit frequency of 1 to 3 days per week. Patients were grouped based on whether their exercise was guided by a target HR determined from a GXT. To assess the relation between GXT and change in exercise training metabolic equivalents of task (METs), we used generalized linear models adjusted for age, gender, race, referral reason, CR visits, CR frequency, METs at start, CR location, and year of participation. Out of 4,455 patients (37% female, 48% White, median age = 62 years), 53% were prescribed a target HR based on a GXT. Compared with no GXT, a GXT was associated with a significantly greater increase in covariate-adjusted METs during CR and percentage change from start (+0.44 METs [95% confidence interval [CI] 0.38 to 0.51] and +17% [95% CI 14% to 19%], respectively). In a sensitivity analysis limited to patients with 24 to 36 visits at ≥2 days per week (n = 1,319), a GXT was associated with a significantly greater increase in covariate-adjusted exercise training METs (+0.51 [95% CI 0.36 to 0.66]; +19% [95% CI 13% to 24%]). In conclusion, to maximize the potential increase in exercise capacity during CR, patients should undergo a GXT to determine an individualized exercise training target HR.

Tracking Cardiac Rehabilitation Utilization in Medicare Beneficiaries: 2017 UPDATE

PURPOSE

This study updates cardiac rehabilitation (CR) utilization data in a cohort of Medicare beneficiaries hospitalized for CR-eligible events in 2017, including stratification by select patient demographics and state of residence.

METHODS

We identified Medicare fee-for-service beneficiaries who experienced a CR-eligible event and assessed their CR participation (≥1 CR sessions in 365 d), engagement, and completion (≥36 sessions) rates through September 7, 2019. Measures were assessed overall, by beneficiary characteristics and state of residence, and by primary (myocardial infarction; coronary artery bypass surgery; heart valve repair/replacement; percutaneous coronary intervention; or heart/heart-lung transplant) and secondary (angina; heart failure) qualifying event type.

RESULTS

In 2017, 412 080 Medicare beneficiaries had a primary CR-eligible event and 28.6% completed ≥1 session of CR within 365 d after discharge from a qualifying event. Among beneficiaries who completed ≥1 CR session, the mean total number of sessions was 25 ± 12 and 27.6% completed ≥36 sessions. Nebraska had the highest enrollment rate (56.1%), with four other states also achieving an enrollment rate >50% and 23 states falling below the overall rate for the United States.

CONCLUSIONS

The absolute enrollment, engagement, and program completion rates remain low among Medicare beneficiaries, indicating that many patients did not benefit or fully benefit from a class I guideline-recommended therapy. Additional research and continued widespread adoption of successful enrollment and engagement initiatives are needed, especially among identified populations.

Exercise Prescription and Progression Practices among US Cardiac Rehabilitation Clinics

Background: Little is known about exercise prescription practices in cardiac rehabilitation (CR). Therefore, the purpose of this study was to understand how initial exercise is prescribed and how exercise intensity is progressed among cardiac patients enrolled in United States CR programs. Methods: A 22-question survey was sent out to US CR clinics. Results: Ninety-three clinics responded to the survey. RPE was the most commonly reported exercise intensity indicator used for prescribing exercise, followed by resting HR + 20–30 bpm. Exercise progression practices were also based on patient sustained RPE values. Conclusions. Exercise prescription practice has become reliant on subjective indicators of exercise intensity. This may limit patient outcomes, such as improvement in functional measures.

Beneficial Effect on Exercise Tolerance of a Comprehensive Rehabilitation Program in Elderly Obese Patients Affected With Heart Disease

Aims: The number of elderly patients affected with multiple chronic diseases is constantly increasing. Even though multiple studies demonstrated a beneficial effect of cardiac rehabilitation, we do not have data on the outcomes in elderly patients with obesity and heart disease. Methods: We studied 772 consecutive obese subjects (275 women; 35.6%) aged ≥70 years, affected with coronary artery disease and/or heart failure. We conducted a symptom limited exercise test at the beginning and at the end of the program, which consisted of aerobic and strength physical activity, diet, and psychological counseling. Results: Mean body mass index (BMI) at baseline was 37.6 ± 4.4 kg/m² and decreased to 36.4 ± 4.3 kg/m² (P < 0.001). At baseline, attained metabolic equivalents (METs) were 4.7 ± 1.7, and by the end of the program, they were 5.6 ± 2.1 (P < 0.001). The mean improvement was 21.6 ± 21.7% (median, 17.6%; 95% CI, 20.0-23.1%). Patients over 80 years old had similar results compared to the younger ones. Diabetics did worse than non-diabetic patients: the improvement they reached was 19.4 ± 18.9% vs. 23.8 ± 23.9% (P = 0.005). The presence of heart failure was significantly related to both the baseline and final performance, but the attained improvement was significantly greater in heart failure patients: 24.3 ± 23.8% vs. 16.3 ± 15.4% (P < 0.001). No patient had adverse events related to the program. Conclusion: This study documents a significant improvement in exercise capacity in elderly obese patients affected with heart disease who underwent a rehabilitation program.

Exercise capacity improvement after cardiac rehabilitation following myocardial infarction and its association with long-term cardiovascular events

AIMS 

Cardiovascular rehabilitation (CR) improves aerobic capacity and quality of life in patients after myocardial infarction (MI). The aim was to examine the associations between exercise capacity improvement and different clinically relevant cardiovascular events.

METHODS AND RESULTS 

This was a registry-based study of post-MI patients, referred to CR. All patients were submitted to exercise testing before and after CR (36 sessions, 2-3 times/week, and combined exercise). Patients were divided into two groups, based on the difference in exercise capacity before and after the CR programme with the cut-off of two metabolic equivalents (METs) improvement. We assessed the correlation between the extent of exercise capacity improvement and the following cardiovascular events: major adverse cardiac events (MACE), cardiovascular-related hospitalizations, and unplanned coronary angiography. A total of 499 patients were included (mean age 56 ± 10 years, 20% women). Both groups significantly improved in terms of exercise capacity, natriuretic peptide levels, resting heart rate, and resting diastolic pressure; however, lipid status significantly improved only in patients with ≥2 METs difference in exercise capacity. A total of 13.4% patients suffered MACE (median follow-up 858 days); 21.8% were hospitalized for cardiovascular reasons (median follow-up 791 days); and 19.8% had at least one unplanned coronary angiography (median follow-up 791 days). Exercise capacity improvement of ≥2 METs was associated with lower rates of MACE, cardiovascular hospitalizations, and unplanned coronary angiography in all examined univariate and multivariate models.

CONCLUSION 

This study has shown that exercise improvement of ≥2 METs is associated with a significant decrease in MACE, cardiac hospitalizations, and unplanned coronary angiography.

A Comparison of Exercise Intensity in Hybrid Versus Standard Phase Two Cardiac Rehabilitation

PURPOSE

To compare exercise training intensity during standard cardiac rehabilitation (S-CR) versus hybrid-CR (combined clinic- and remote home-/community-based).

METHODS

The iATTEND (improving ATTENDance to cardiac rehabilitation) trial is currently enrolling subjects and randomizing patients to S-CR versus hybrid-CR. This substudy involves the first 47 subjects who completed ≥18 CR sessions. Patients in S-CR completed all visits in a typical phase II clinic-based setting and patients in hybrid-CR completed up to 17 of their sessions remotely using telehealth (TH). Exercise training intensity in both CR settings is based on heart rate (HR) data from each CR session, expressed as percent HR reserve.

RESULTS

Among patients in both study groups, there were no serious adverse events or falls that required hospitalization during or within 3 hr after completing a CR session. Expressed as a percentage of HR reserve, the overall mean exercise training intensities during both the S-CR sessions and the TH-CR sessions from hybrid-CR were not significantly different at 63 ± 12% and 65 ± 10%, respectively (P = .29).

CONCLUSION

This study showed that hybrid-CR delivered using remote TH results in exercise training intensities that are not significantly different from S-CR.

Adherence and exercise mode in supervised exercise therapy for peripheral artery disease

Supervised exercise therapy (SET) is a first-line treatment for people with peripheral artery disease (PAD). However, data on patient adherence to SET are limited. In addition, while intermittent treadmill exercise has been widely tested, no studies have investigated recumbent total body stepping (step-ex). We examined whether exercise mode (treadmill walking [n = 17], step-ex [n = 18], or a multimodal approach [n = 18]) affected adherence to a 12-week SET program. We also investigated the potential safety and viability of step-ex for people with PAD by looking at change in exercise training capacity (highest metabolic equivalent of tasks [METs] achieved and highest total MET-minutes achieved per session). The 53 participants comprised 50% female candidates (n = 26) and were (mean [SD]) 74.2 (8.3) years old, with an ankle-brachial index of 0.70 (0.19). Overall adherence to SET was 62%. There was a difference in adherence between groups (P = .022), with the multimodal group (73.6% [21.5%]) higher than the treadmill group (50.2% [28.8%], P = .010). Treadmill participants (n [%]) (8 [47.1%]) dropped out at a higher rate than the multimodal group (3 [16.7%], P = .053). All groups increased the exercise training capacity. The multimodal group achieved greater improvement in total MET-minutes achieved per session (61.5 [45.1]) than the treadmill group (14.7 [44.3]) (P = .008).A multimodal approach to PAD exercise therapy resulted in higher adherence and greater change in exercise training capacity. Step-ex was safe for people with PAD. While further study is warranted, it is appropriate for SET programs to consider a multimodal approach using step-ex, especially given the varied health and physical ability of the PAD population.

Exercise Prescription Guidelines for Cardiovascular Disease Patients in the Absence of a Baseline Stress Test

Aerobic exercise is a core component of cardiac rehabilitation (CR). Leading organizations recommend that the exercise prescriptions should be based on a symptom limited baseline graded exercise test (GXT). However, recent evidence suggests that only ~30% of CR clinics perform baseline GXTs. Consequently, exercise prescriptions including exercise progression in CR are not following standard exercise prescription guidelines. Therefore, the purpose of this review is to provide clinicians with evidence-based techniques for prescribing exercise in the absence of a baseline GXT. Intensity indicators (e.g., heart rate, perceived exertion) are reviewed, along with special exercise considerations for various disease states (e.g., heart failure, peripheral artery disease, and coronary artery disease). Baseline exercise testing remains the gold standard approach for prescribing exercise among heart disease patients, however, clinicians must be prepared to safely develop and monitor patients when a baseline GXT is not performed.

Comparison of Treadmill and Cycle Ergometer Exercise During Cardiac Rehabilitation: A Meta-analysis

OBJECTIVE

To compare treadmill versus cycling-based exercise in cardiac rehabilitation (CR) on functional capacity (FC) outcomes.

DATA SOURCE

Databases were searched for randomized studies using single modality continuous exercise.

STUDY SELECTION

Studies implemented a continuous cycling or treadmill protocol for patients with either coronary artery disease (CAD) or chronic heart failure (CHF). The effect of single modality exercise on FC (VO₂peak) was analyzed. Differences in the effect of CR on FC was assessed between the mode subgroup (cycling vs treadmill) and disease state subgroup (CAD vs CHF) within both the cycling and treadmill groups.

DATA EXTRACTION

Data were extracted from 23 studies including 600 patients (mean age 60y, 86% men).

DATA SYNTHESIS

There was a significant difference in effect size between studies that used cycling, Hedges' g=0.85 (95% confidence interval [95% CI], 0.52-1.17; k=13) and studies that used treadmill exercise, Hedges' g=0.46 (95% CI, 0.22-0.70; k=8). Within cycling studies (n=14), FC was higher among CAD patients, Hedges' g=1.03 (95% CI, 0.65-1.42; k=9) compared to those with CHF, Hedges' g=0.40 (95% CI, 0.09-0.71; k=4, P<.001). Conversely, among treadmill studies (n=9), FC was higher among CHF patients, Hedges' g=0.94 (95% CI, 0.23-1.65; k=2) compared to CAD, Hedges' g=0.33 (95% CI, 0.19-0.47; k=5; P<.01).

CONCLUSIONS

According to identified studies, when cycling was the primary mode of exercise in CR, there was larger change in FC compared to treadmill exercise. In addition, CAD patients experienced greater gains in FC when cycling was the primary mode of exercise in CR, while CHF patients benefited more from treadmill-based exercise programs.

The Influence of Exercise Workload Progression Across 36 Sessions of Cardiac Rehabilitation on Functional Capacity

Defining time frames throughout cardiac rehabilitation (CR) to progress exercise workloads may lead to improve functional capacity outcomes. The purpose of this study was to investigate the role of exercise progression on functional capacity among cardiac patients enrolled in CR. This was a retrospective database analysis study. Extracted data included: Demographic, functional capacity (in METs), and exercise intensity during exercise sessions 2, 12, 24, and 36 of CR from 150 patients who completed a 36-session program. Progression of exercise was determined by calculating percent change in treadmill exercise workload within predefined time frames of CR. The time frames were percent change from exercise session 2 to 12 (“%ΔS2–S12), 12 to 24 (%ΔS12–S24), and 24 to 36 (%ΔS24–S36). A multiple linear regression model was developed to predict change in functional capacity (ΔMETs). A significant proportion (21%) of total variation in ΔMETs was predicted by %ΔS2–12, %ΔS12–24, %ΔS24–36, age, sex, and body mass index (BMI). Percent changes between sessions 12 to 24 (%ΔS12–24; β = 0.17, p = 0.03) and 24 to 36 (%ΔS24–36; β = 0.23, p < 0.01) were significant predictors. Progressing patients between sessions 12 to 24 and 24 to 36 predicted significant changes in functional capacity and reinforced the importance of exercise progression across all 36 sessions of CR.

Exercise training workloads in cardiac rehabilitation are associated with clinical outcomes in patients with heart failure

BACKGROUND

In patients with coronary heart disease, the exercise workload (i.e., metabolic equivalents of task, METs) at which patients exercise train upon entry and completion of cardiac rehabilitation (CR) are independently related to prognosis. Unknown is the association between exercise training workloads in CR and clinical outcomes in patients with heart failure (HF).

METHODS

Patients with HF who participated in an early outpatient CR program were used in this retrospective analysis. Exercise workloads upon entry and completion of CR were converted to METs. The primary outcome was all-cause mortality and the secondary outcome was HF hospitalization. Cox regression analysis was used to assess the adjusted risk between MET levels in CR and clinical outcomes.

RESULTS

Among 707 patients, the median exercise training workload at the start and end of CR was 2.5 METs (IQR 2.1 to 3.1 METs) and 3.2 METS (IQR 2.7 to 4.1 METs), respectively, for men and 2.2 METs (IQR 1.9 to 2.6 METs) and 2.9 METS (IQR 2.3 to 3.4 METs), respectively, for women. There were 242 deaths and 266 HF hospitalizations. METs achieved at the end of CR had the strongest independent association with all-cause mortality (adjusted HR, 95% CI: 0.58, 0.48-0.70) and HF hospitalization (adjusted HR, 95% CI: 0.62, 0.52-0.74). Each 1 MET higher work load at the end of CR was associated with a 42% and 38% lower adjusted risk for all-cause mortality and HF hospitalization, respectively.

CONCLUSIONS

In a diverse cohort of patients with chronic HF our data suggests that an easily accessible measure of exercise capacity (i.e., METs) that is collected during CR is independently associated with the adjusted risk for both all-cause mortality and HF-specific hospitalization. Training at MET levels <3.5 METs identifies patients that might benefit from closer clinical surveillance and reinforced adherence to medical and lifestyle preventive strategies.

Examination of clinical and psychosocial determinants of exercise capacity change in cardiac rehabilitation

PURPOSE

Most cardiac rehabilitation (CR) completers improve in multiple functional and psychosocial domains. However, not all demonstrate uniform improvement in functional indicators such as exercise capacity. This study examined baseline predictors and correlates of change in exercise capacity from CR intake to completion.

METHODS

CR participants (n = 488) completed assessment of metabolic equivalents (METs) via treadmill stress test, depressive symptoms, quality of life, and social support at intake and discharge. Associations between demographic, clinical, and psychosocial factors and MET changes was tested with linear regression.

RESULTS

METs increased from intake to discharge (1.91 ± 1.48, p < .001). Younger age (p < .001), lower BMI (p < .001), and lower weight (p < .01) were associated with greater MET change. Greater percentage weight loss (p < .05), and self-reported improvements in physical functioning (p < .001) and bodily pain (p < .01) were concurrently related to MET change.

CONCLUSIONS

Older CR attendees and those with higher baseline BMI may benefit from tailored intervention to ensure maximum benefit in exercise capacity.

Exercise Training Workloads Upon Exit From Cardiac Rehabilitation in Men and Women: THE HENRY FORD HOSPITAL EXPERIENCE

PURPOSE

To describe exercise training workloads, estimated as metabolic equivalents of task (METs) both upon exit from cardiac rehabilitation (CR) and as the change in MET level following CR, stratified by age, sex, initial MET level, number of sessions completed, and qualifying event at entry into CR.

METHODS

A retrospective study involving 8319 (31% female) patients who completed ≥9 exercise training sessions in the early outpatient CR program at Henry Ford Hospital. Exercise training MET levels achieved during CR were estimated on the basis of the speed and grade recorded from a treadmill. Exercise training METs at the start of CR were defined as the average of the second and third sessions, whereas MET level upon exit from CR was determined from the average of the last 2 patient encounters.

RESULTS

The overall mean MET level while training just prior to exit from CR was 3.9 ± 1.4 (4.1 ± 1.4 and 3.3 ± 1.0 in men and women, respectively). The mean change in METs after CR was 1.3 ± 1.1 (+45% ± 37%) and 0.9 ± 0.7 (+40% ± 32%) in men and women, respectively.

CONCLUSIONS

In a large and demographically diverse cohort of patients who participated in CR, increases in mean workload (ie, METs) during exercise training were observed that approximated 45% in men and 40% in women. These data could be considered when establishing benchmarks for program-related performance outcome measures.

Translation of an evidence-based therapeutic exercise program for patients with peripheral artery disease

The purpose of this study was to implement and evaluate quality outcomes including referral, enrollment, and completion rates of a new peripheral artery disease (PAD)-specific supervised exercise therapy (SET) program within a preexisting clinical exercise wellness program and to evaluate the clinical effectiveness and patient-centered outcomes derived from 12 weeks of PAD-specific SET. Recruited participants completed an individualized, minimally supervised, PAD-specific SET program based on the AHA-ACC guidelines. Exercise workloads (metabolic equivalents of task [METs]) were tracked and evaluated throughout the program. Short Physical Performance Battery, 6-minute walk test (6MWT) Walking Impairment Questionnaire, Short-Form 36 (SF-36), and Peripheral Artery Disease Quality of Life Questionnaire (PADQOL) were assessed before and after the program. Paired t-tests were used to examine differences between baseline and follow-up outcome variables. On average, participants (n = 46) attended 23 (standard deviation [SD] 12.9) out of the possible 36 training sessions, for a 64% attendance rate. Among participants who used treadmill walking as the primary mode of exercise (n = 40), the overall mean MET level just prior to program completion was 3.79 (SD 1.49), which represented an increase of 0.92 (34%) METs compared to baseline (P < .001). Total distance on the 6MWT increased 115 (11%) feet (P = .011), which is considered a clinically meaningful improvement. Significant improvements were noted in the PADQOL: symptoms and limitations in physical functioning (P = .007). This study demonstrates that a minimally staffed PAD-specific SET program can improve functional performance in patients with claudication due to PAD and serves as a foundation to help build a clinically effective, Centers for Medicare and Medicaid reimbursed PAD-specific rehabilitation program.

Change in Maximal Exercise Capacity Is Associated With Survival in Men and Women

OBJECTIVE

To describe the relationship between change in maximal exercise capacity (MEC) over time and risk of all-cause mortality separately in men and women.

PATIENTS AND METHODS

Consecutive patients (n=10,854; mean ± SD age, 54±11 years; 43% women; 30% nonwhite) who completed 2 physician-referred exercise tests between January 2, 1991, and May 28, 2009, were identified from the Henry Ford Exercise Testing (FIT) Project. The MEC was quantified in metabolic equivalents of task (METs) calculated from peak workload on a treadmill and adjusted to the equivalent for a 50-year-old man. Multivariable Cox proportional hazards regression was performed to assess risk of all-cause mortality associated with change in MEC based on (1) change from age-/sex-adjusted low fitness (<8 METs) to intermediate or high fitness and (2) an absolute change in METs.

RESULTS

Relative to patients with low fitness at both tests, increasing from low to intermediate or high fitness was associated with lower risk of all-cause mortality (adjusted hazard ratio [aHR] = 0.63 [95% CI, 0.45-0.87] in men and 0.56 [95% CI, 0.34-0.91] in women). Each 1-MET increase in age-/sex-adjusted MEC between baseline and follow-up was associated with an aHR of 0.87 (95% CI, 0.84-0.91) in men and 0.84 (95% CI, 0.79-0.89) in women, with no significant interaction by sex (P=.995). Similar aHRs were observed in a subgroup with intermediate fitness at baseline.

CONCLUSION

In men and women referred for an exercise stress test, change in MEC over time is inversely related to risk of all-cause mortality.