Progression of Exercise Training in Early Outpatient Cardiac Rehabilitation: AN OFFICIAL STATEMENT FROM THE AMERICAN ASSOCIATION OF CARDIOVASCULAR AND PULMONARY REHABILITATION

Impact of cardiac rehabilitation exercise frequency on exercise capacity in patients with coronary artery disease: a retrospective study

Cardiac rehabilitation (CR) significantly improves cardiovascular outcomes in patients with coronary artery disease (CAD). International guidelines vary in the minimum recommended frequency of supervised exercise from 1 to 3 sessions per week. This is the first study in the Middle East and North African regions assessing the impact of 2 versus 3 days/week of supervised exercise on peak exercise capacity in patients with CAD. Single-center retrospective cohort study involving 362 patients enrolled in the only CR center in the State of Qatar. Only high-quality data was included by strict evaluation of compliance to the exercise intervention. Fifty patients who underwent a symptom-limited exercise test before and after CR were included (31 patients on 2 days/week, 19 on 3 days/week). No significant differences were observed in baseline characteristics between groups. Exercise intervention differed significantly between groups in exercise training frequency (2 days/week: 1.97 ± 0.2 vs. 3 days/week: 2.7 ± 0.3; p < 0.00). Peak exercise capacity as peak metabolic equivalents of task (MET) significantly increased in both groups (2 days/week: Pre 8.3 ± 2.4 vs. Post 9.4 ± 2.9, p-value 0.00; 3 days/week: Pre 7.4 ± 1.6 vs. Post 8.4 ± 2.0, p-value 0.00). No significant difference was observed between groups for change in Peak Exercise Capacity (2 days/week 1.1 ± 1.1 vs. 3 days/week 1.0 ± 0.9, p = 0.87). When the total number of exercise sessions is equal, supervised exercise frequencies of 2 and 3 days/week may significantly and equally improve peak exercise capacity in patients with CAD.

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.

Post-Myocardial Infarction Rehabilitation: The Absence in the Rehabilitation Process of the Diaphragm Muscle

Myocardial infarction (MI) is one of the leading causes of death worldwide. There can be many reasons that cause MI, such as a sedentary lifestyle, a disordered diet, harmful habits such as smoking and alcoholism, concomitant congenital or acquired systemic pathologies. Patients who survive the acute event suffer a functional alteration of multiple body systems. The various cardiology associations recommend starting a rehabilitation process, pursuing the main objective of improving the patient's health status. A negative consequence that can be linked to MI is the dysfunction of the main breathing muscle, the diaphragm. The diaphragm is essential not only for respiratory mechanisms but also for adequate production of cardiac pressures. Post-MI patients present a reduction in the performance of the diaphragm muscle, and this condition can become a risk factor for further relapses or for the onset of heart failure. The article reviews the rehabilitation path for post-MI patients, to highlight the absence given to the diaphragm in the recovery of the patient's health status. The text reviews the post-MI diaphragmatic adaptation to highlight the importance of including targeted training for the diaphragm muscle in the rehabilitation process.

Effects of a physical therapist-driven individualized hybrid model of the exercise component of cardiac rehabilitation on patient outcomes: a prospective single group, time-series design

PURPOSE

The aim of this prospective single group, time-series study was to determine the feasibility, adherence, and effectiveness of an individualized physical therapist (PT)-driven hybrid model of the exercise component of cardiac rehabilitation (CR) that uses a novel intensity-recovery progression protocol (IRPP) and cardiac testing template (CTT) to assess achieved heart rate (HR) intensity, HR recovery, and intensity-recovery total to guide treatment.

METHODS

Assessment of a questionnaire, treadmill 6-min walk (6MW), 1-min sit-to-stand (1STS), 1-min step, and 1-min agility square tests were assessed on 100 participants. Compared to traditional CR the 36-visit 1:1 hybrid model was individualized using the IRPP program and CTT.

RESULTS

Adherence was 35% (timely) and 44% (overall) completion. The per-protocol analysis (PPA) and intent-to-treat (ITT) analysis suggest significant improvement in objective assessments baseline to visit 15 (PPA = 11 of 14) (ITT = 13 of 14), baseline to visit 30 (PPA = 12 of 14) (ITT = 12 of 14) and visit 15 to visit 30 (PPA = 9 of 14) (ITT = 10 of 14). Improvement beyond the minimal clinically important difference (MCID) was 94.3% in the 6MW and 91.4% in the 1STS.

CONCLUSIONS

The PT-driven IRPP program was feasible in terms of adherence and safety, showing significant improvement in a majority of assessments. Analysis of HR using the CTT may help clinical decision making for progression in CR.Implications for rehabilitationCardiac rehabilitation (CR) is an underutilized means of improving health for people recovering from cardiac surgery.People recovering from cardiac surgery have complex reasons for why they choose to enroll in, drop out from, or complete a CR program.Reporting of outcomes in CR and progression in intensity is not often individualized.An individualized physical therapist driven CR program using both subjective and objective assessments may be successful at improving adherence and effectiveness in this cohort.

A Review of High-Intensity Interval Training in Heart Transplant Recipients: Current Knowledge and Future Perspectives

OBJECTIVE

This review reports how exercise-based rehabilitation strategies have developed over the past decades, and it specifically focuses on the effectiveness, safety, and implementation of high-intensity interval training (HIIT). It provides an overview of the historical progression, main research findings, and considerations surrounding HIIT as the preferred exercise modality for recipients of heart transplant (HTx).

REVIEW METHODS

The review includes a timeline of studies spanning from 1976-2023. The 2017 Cochrane systematic review on exercise-based cardiac rehabilitation in recipients of HTx serves as the main knowledge base (≥2015). Additionally, literature searches in PubMed/Medline and ClinicalTrials.gov have been performed, and all reviews and studies reporting the effects of moderate- to high-intensity exercise in recipients of HTx, published in 2015 or later have been screened.

SUMMARY

High-intensity interval training has gained prominence as an effective exercise intervention for recipients of HTx, demonstrated by an accumulation of performed studies in the past decade, although implementation in clinical practice remains limited. Early restrictions on HIIT in HTx recipients lacked evidence-based support, and recent research challenges these previous restrictions. High-intensity interval training results in greater improvements and benefits compared with moderate-intensity continuous training in the majority of studies. While HIIT is now regarded as generally suitable on a group level, individual assessment is still advised. The impact of HIIT involves reinnervation and central and peripheral adaptations to exercise, with variations in recipent responses, especially between de novo and maintenance recipients, and also between younger and older recipients. Long-term effects and mechanisms behind the HIIT effect warrant further investigation, as well as a focus on optimized HIIT protocols and exercise benefits.

Accurate Prediction Equations for Ventilatory Thresholds in Cardiometabolic Disease When Gas Exchange Analysis is Unavailable: Development and Validation

AIMS

To develop and validate equations predicting heart rate (HR) at the first and second ventilatory thresholds (VTs) and an optimized range-adjusted prescription for patients with cardiometabolic disease (CMD). To compare their performance against guideline-based exercise intensity domains.

METHODS

Cross-sectional study involving 2,868 CMD patients from nine countries. HR predictive equations for first and second VTs (VT1, VT2) were developed using multivariate linear regression with 975 cycle-ergometer cardiopulmonary exercise tests (CPET). 'Adjusted' percentages of peak HR (%HRpeak) and HR reserve (%HRR) were derived from this group. External validation with 1,893 CPET (cycle-ergometer or treadmill) assessed accuracy, agreement, and reliability against guideline-based %HRpeak and %HRR prescriptions using mean absolute percentage error (MAPE), Bland-Altman analyses, intraclass correlation coefficients (ICC).

RESULTS

HR predictive equations (R²: 0.77 VT1, 0.88 VT2) and adjusted %HRR (VT1: 42%, VT2: 77%) were developed. External validation demonstrated superiority over widely used guideline-directed intensity domains for %HRpeak and %HRR. The new methods showed consistent performance across both VTs with lower MAPE (VT1: 7.1%, VT2: 5.0%), 'good' ICC for VT1 (0.81, 0.82) and 'excellent' for VT2 (0.93). Guideline-based exercise intensity domains had higher MAPE (VT1: 6.8%-21.3%, VT2: 5.1%-16.7%), 'poor' to 'good' ICC for VT1, and 'poor' to 'excellent' for VT2, indicating inconsistencies related to specific VTs across guidelines.

CONCLUSION

Developed and validated HR predictive equations and the optimized %HRR for CMD patients for determining VT1 and VT2 outperformed the guideline-based exercise intensity domains and showed ergometer interchangeability. They offer a superior alternative for prescribing moderate intensity exercise when CPET is unavailable.

Quantifying Improvement in V˙ o2peak and Exercise Thresholds in Cardiovascular Disease Using Reliable Change Indices

PURPOSE

Improving aerobic fitness through exercise training is recommended for the treatment of cardiovascular disease (CVD). However, strong justifications for the criteria of assessing improvement in key parameters of aerobic function including estimated lactate threshold (θ LT ), respiratory compensation point (RCP), and peak oxygen uptake (V˙ o2peak ) at the individual level are not established. We applied reliable change index (RCI) statistics to determine minimal meaningful change (MMC RCI ) cutoffs of θ LT , RCP, and V˙ o2peak for individual patients with CVD.

METHODS

Sixty-six stable patients post-cardiac event performed three exhaustive treadmill-based incremental exercise tests (modified Bruce) ∼1 wk apart (T1-T3). Breath-by-breath gas exchange and ventilatory variables were measured by metabolic cart and used to identify θ LT , RCP, and V˙ o2peak . Using test-retest reliability and mean difference scores to estimate error and test practice/exposure, respectively, MMC RCI values were calculated for V˙ o2 (mL·min -1. kg -1 ) at θ LT , RCP, and V˙ o2peak .

RESULTS

There were no significant between-trial differences in V˙ o2 at θ LT ( P = .78), RCP ( P = .08), or V˙ o2peak ( P = .74) and each variable exhibited excellent test-retest variability (intraclass correlation: 0.97, 0.98, and 0.99; coefficient of variation: 6.5, 5.4, and 4.9% for θ LT , RCP, and V˙ o2peak , respectively). Derived from comparing T1-T2, T1-T3, and T2-T3, the MMC RCI for θ LT were 3.91, 3.56, and 2.64 mL·min -1. kg -1 ; 4.01, 2.80, and 2.79 mL·min -1. kg -1 for RCP; and 3.61, 3.83, and 2.81 mL·min -1. kg -1 for V˙ o2peak . For each variable, MMC RCI scores were lowest for T2-T3 comparisons.

CONCLUSION

These MMC RCI scores may be used to establish cutoff criteria for determining meaningful changes for interventions designed to improve aerobic function in individuals with CVD.

Effect of maximal-intensity and high-intensity interval training on exercise capacity and quality of life in patients with acute myocardial infarction: a randomized controlled trial

BACKGROUND

An increase in V̇O2max is important for acute myocardial infarction morbidity, and recurrence rate and intensity have been suggested as important factors in improving V̇O2max.

AIM

The aim of this study was to compare the effects of maximal-intensity interval training (MIIT) and high-intensity interval training (HIIT) on exercise capacity and health-related Quality of Life (HRQoL) in patients with acute myocardial infarction (MI) at low and moderate cardiac risk in cardiac rehabilitation (CR). This study secondarily aimed to compare the effects of hospital-based phase II CR and usual care.

DESIGN

This study is a randomized controlled trial.

SETTING

Outpatient Rehabilitation Setting.

POPULATION

Fifty-nine patients with acute MI were randomly assigned to the MIIT (N.=30) or HIIT (N.=29) group, and 32 to the usual care group.

METHODS

Twice a week, an intervention was conducted for nine weeks in all groups. The maximum oxygen intake (V̇O2max) and MacNew Heart Disease HRQoL were evaluated before and after intervention.

RESULTS

A significant interaction was observed between time and group for V̇O2max (P<0.001). The MIIT group showed greater improvement than those exhibited by the HIIT and usual care groups (P<0.05). Similarly, a significant time and group interaction was observed on the MacNew Global, Physical, and Emotional scales (P<0.05), but not on the social scale (P>0.05).

CONCLUSIONS

Compared to HIIT and usual care, MIIT significantly increased the V̇O2max and was as safe as HIIT in patients with acute MI with low and moderate cardiac risk in CR. Additionally, MIIT and HIIT were superior to usual care in terms of improving the HRQoL.

CLINICAL REHABILITATION IMPACT

Our results suggest that increased intensity in phase II CR could result in better outcomes in terms of V̇O2max increment in patients with acute MI and low and moderate cardiac risk in CR.

Efficacy of early cardiac rehabilitation after acute myocardial infarction: Randomized clinical trial protocol

The acute myocardial infarction (AMI) present high mortality rate that may be reduced with cardiac rehabilitation. Despite its good establishment in outpatient care, few studies analyzed cardiac rehabilitation during hospitalization. Thus, this study aims to clarify the safety and efficacy of early cardiac rehabilitation after AMI. This will be a clinical, controlled, randomized trial with blind outcome evaluation and a superiority hypothesis. Twenty-four patients with AMI will be divided into two groups (1:1 allocation ratio). The intervention group will receive an individualized exercise-based cardiac rehabilitation protocol during hospitalization and a semi-supervised protocol after hospital discharge; the control group will receive conventional care. The primary outcomes will be the cardiac remodeling assessed by cardiac magnetic resonance imaging, functional capacity assessed by maximal oxygen consumption, and cardiac autonomic balance examined via heart rate variability. Secondary outcomes will include safety and the total exercise dose provided during the protocol. Statistical analysis will consider the intent-to-treat analysis. Trial registration. Trial registration number: Brazilian Registry of Clinical Trials (ReBEC) (RBR- 9nyx8hb).

Lower-Socioeconomic Status Patients Have Extremely High-Risk Factor Profiles on Entry to Cardiac Rehabilitation

PURPOSE

Patients with lower socioeconomic status (SES) have higher rates of cardiovascular events, yet are less likely to engage in secondary prevention such as cardiac rehabilitation (CR). Given the low number of lower-SES patients entering CR, characterization of this population has been difficult. Our CR program specifically increased recruitment of lower-SES patients, allowing for careful comparison of medical, psychosocial, and behavioral risk factors between lower- and higher-SES patients eligible for secondary prevention.

METHODS

Demographic and clinical characteristics were prospectively gathered on consecutive individuals entering phase 2 CR from January 2014 to December 2022. Patients were classified as lower SES if they had Medicaid insurance. Statistical methods included chi-square and nonpaired t tests. A P value of <.01 was used to determine significance.

RESULTS

The entire cohort consisted of 3131 individuals. Compared with higher-SES patients, lower-SES individuals (n = 405; 13%) were a decade younger (57.1 ± 10.4 vs 67.2 ± 11.2 yr), 5.8 times more likely to be current smokers (29 vs 5%), 1.7 times more likely to have elevated depressive symptoms, and significantly higher body mass index, waist circumference, and glycated hemoglobin A 1c , with more abnormal lipid profiles (all P s < .001). Despite being a decade younger, lower-SES patients had lower measures of cardiorespiratory fitness and self-reported physical function (both P s < .001).

CONCLUSION

Lower-SES patients have a remarkably prominent high-risk cardiovascular disease profile, resulting in a substantially higher risk for a recurrent coronary event than higher-SES patients. Accordingly, efforts must be made to engage this high-risk population in CR. It is incumbent on CR programs to ensure that they are appropriately equipped to intervene on modifiable risk factors such as low cardiorespiratory fitness, obesity, depression, and smoking.

Peak Exercise Capacity and Angina Threshold Improvement after Cardiac Rehabilitation in a Patient with Stable Angina and Low Hemoglobin

Cardiac rehabilitation (CR) is recommended for all patients with stable angina (SA) as an effective treatment. Hemoglobin (Hgb) levels predict exercise performance and may affect symptom threshold in SA patients. A multidisciplinary CR intervention was individually tailored for a 72-year-old patient with a diagnosis of SA, low Hgb (<10 g/dL), and typical chest pain at light-to-moderate exercise (<5 metabolic equivalent task), who was stratified as at high risk for cardiac events during exercise. Two symptom-limited exercise tests were performed before and after 36 sessions of supervised exercise training producing near-optimal accumulated total volume load and chronic training load. In this case report, we show that an individually tailored CR intervention in a patient with SA and low Hgb is feasible, effective, and safe at reducing the burden of symptoms while increasing peak exercise capacity, health-related quality of life, and physical activity engagement.

Cardio-Oncology: Managing Cardiovascular Complications of Cancer Therapies

This narrative review explores the complex relationship between cancer medicines and cardiovascular health in the junction of oncology and cardiology, known as cardio-oncology. The study examines the historical development of cancer treatments and highlights the growing importance of cardiovascular problems in patient care. This text delves into the topic of cardiotoxicity, examining both conventional chemotherapeutic drugs like anthracyclines and more recent tyrosine kinase and immune checkpoint inhibitors. The complex molecular and cellular mechanisms that control cardiovascular problems are explained, including an understanding of how genetic predisposition influences an individual's sensitivity. The narrative expands into the crucial realm of risk stratification and evaluation, revealing advanced instruments for identifying cardiovascular risk in cancer patients. The importance of non-invasive imaging methods and biomarkers in early detection and continuous monitoring is emphasized. The prioritization of preventive tactics emphasizes the need to take proactive measures incorporating therapies to protect the heart throughout cancer treatment. It also highlights the significance of making lifestyle improvements to reduce risk factors. The narrative emphasizes the changing collaborative treatment environment, advocating for merging oncologists and cardiologists in a coordinated endeavor to maximize patient outcomes. In addition to clinical factors, the review explores the critical domain of patient education and support, acknowledging its crucial role in promoting informed decision-making and improving overall patient well-being. The latter portions of the text anticipate and consider upcoming treatments and existing research efforts that offer the potential for the future of cardio-oncology. This review seeks to provide a detailed viewpoint on the intricate connection between cancer treatments and cardiovascular well-being. Its objective is to encourage a more profound comprehension of the subject and prompt careful contemplation regarding the comprehensive care of cancer patients who confront the intricate difficulties presented by their treatment plans.

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.

Revolutionizing Cardiac Care: A Comprehensive Narrative Review of Cardiac Rehabilitation and the Evolution of Cardiovascular Medicine

Cardiovascular disease (CVD) stands as a global health crisis, with its complex web of conditions, including coronary artery disease, heart failure, hypertension, and stroke, continuing to exact a heavy toll on individuals and healthcare systems worldwide. Despite substantial advances in medical technology and pharmaceutical interventions, CVD remains a formidable adversary, necessitating innovative prevention, management, and rehabilitation approaches. In tracing the historical trajectory of CVD, the narrative reveals the antiquated practices of early 20th-century medicine, marked by extended bed rest as the primary modality for heart-related conditions. It underscores the critical juncture when exercise was first recognized as a therapeutic tool for cardiac health, setting the stage for the evolution of cardiac rehabilitation (CR). CR programs have transcended their initial focus on exercise, expanding to encompass dietary guidance, psychosocial support, and comprehensive risk factor modification. These holistic interventions enhance physical recovery and address the psychosocial and lifestyle aspects of CVD management, ultimately improving patients' overall well-being. CR programs increasingly leverage advanced technologies and personalized strategies to tailor interventions to individual patient needs, ultimately enhancing outcomes and reducing the burden of CVD. In conclusion, this narrative review illuminates the transformative journey of cardiac care, with a particular spotlight on the indispensable role of CR in reshaping the landscape of cardiovascular medicine. By evolving from historical practices to comprehensive, patient-centered interventions, CR has made significant strides in improving the prognosis, quality of life, and holistic well-being of individuals grappling with the complexities of CVD. Understanding this historical context and the contemporary advancements is paramount for healthcare professionals and policymakers as they navigate the intricate terrain of cardiovascular medicine and endeavor to mitigate the impact of this pervasive disease.

Cluster Sets to Prescribe Interval Resistance Training: A Potential Method to Optimise Resistance Training Safety, Feasibility and Efficacy in Cardiac Patients

The integration of resistance training for cardiac patients leads to important health outcomes that are not optimally obtained with aerobic exercise; these include an increase in muscle mass, maintenance of bone mineral density, and improvements in muscular fitness parameters. Despite the proliferation of evidence supporting resistance exercise in recent decades, the implementation of resistance training is underutilised, and prescription is often sub-optimal in cardiac patients. This is frequently associated with safety concerns and inadequate methods of practical exercise prescription. This review discusses the potential application of cluster sets to prescribe interval resistance training in cardiac populations. The addition of planned, regular passive intra-set rest periods (cluster sets) in resistance training (i.e., interval resistance training) may be a practical solution for reducing the magnitude of haemodynamic responses observed with traditional resistance training. This interval resistance training approach may be a more suitable option for cardiac patients. Additionally, many cardiac patients present with impaired exercise tolerance; this model of interval resistance training may be a more suitable option to reduce fatigue, increase patient tolerance and enhance performance to these workloads. Practical strategies to implement interval resistance training for cardiac patients are also discussed. Preliminary evidence suggests that interval resistance training may lead to safer acute haemodynamic responses in cardiac patients. Future research is needed to determine the efficacy and feasibility of interval resistance training for health outcomes in this population.

A Machine Learning Approach to Developing an Accurate Prediction of Maximal Heart Rate During Exercise Testing in Apparently Healthy Adults

PURPOSE

Maximal heart rate (HR max ) continues to be an important measure of adequate effort during an exercise test. The aim of this study was to improve the accuracy of HR max prediction using a machine learning (ML) approach.

METHODS

We used a sample from the Fitness Registry of the Importance of Exercise National Database, which included 17 325 apparently healthy individuals (81% males) who performed a maximal cardiopulmonary exercise test. Two standard formulas for HR max prediction were tested: Formula1 = 220 - age (yr), root-mean-squared error (RMSE) 21.9, relative root-mean-squared error (RRMSE) 1.1; and Formula2 = 209.3 - 0.72 × age (yr), RMSE 22.7 and RRMSE 1.1. For ML model prediction, we used age, weight, height, resting HR, and systolic and diastolic blood pressure. The following ML algorithms to predict HR max were applied: lasso regression (LR), neural networks (NN), support vector machine (SVM) and random forests (RF). An evaluation was performed using cross-validation and by computing the RMSE and RRMSE, Pearson correlation, and Bland-Altman plots. The best predictive model was explained with Shapley Additive Explanations (SHAP).

RESULTS

The HR max for the cohort was 162 ± 20 bpm. All ML models improved HR max prediction and reduced RMSE and RRMSE compared with Formula1 (LR: 20.2%, NN: 20.4%, SVM: 22.2%, and RF: 24.7%). The predictions of all algorithms significantly correlated with HR max ( r = 0.49, 0.51, 0.54, 0.57, respectively; P < .001). Bland-Altman analysis demonstrated lower bias and 95% CI for all ML models in comparison with standard equations. The SHAP explanation showed a high impact of all selected variables.

CONCLUSIONS

Machine learning, particularly the RF model, improved prediction of HR max using readily available measures. This approach should be considered for clinical application to refine HR max prediction.

Exercise intensity domains determined by heart rate at the ventilatory thresholds in patients with cardiovascular disease: new insights and comparisons to cardiovascular rehabilitation prescription recommendations

Objectives

To compare the elicited exercise responses at ventilatory thresholds (VTs: VT1 and VT2) identified by cardiopulmonary exercise testing (CPET) in patients with cardiovascular disease (CVD) with the guideline-directed exercise intensity domains; to propose equations to predict heart rate (HR) at VTs; and to compare the accuracy of prescription methods.

Methods

A cross-sectional study was performed with 972 maximal treadmill CPET on patients with CVD. First, VTs were identified and compared with guideline-directed exercise intensity domains. Second, multivariate linear regression analyses were performed to generate prediction equations for HR at VTs. Finally, the accuracy of prescription methods was assessed by the mean absolute percentage error (MAPE).

Results

Significant dispersions of individual responses were found for VTs, with the same relative intensity of exercise corresponding to different guideline-directed exercise intensity domains. A mathematical error inherent to methods based on percentages of peak effort was identified, which may help to explain the dispersions. Tailored multivariable equations yielded r2 of 0.726 for VT1 and 0.901 for VT2. MAPE for the novel VT1 equation was 6.0%, lower than that for guideline-based prescription methods (9.5 to 23.8%). MAPE for the novel VT2 equation was 4.3%, lower than guideline-based methods (5.8%-19.3%).

Conclusion

The guideline-based exercise intensity domains for cardiovascular rehabilitation revealed inconsistencies and heterogeneity, which limits the currently used methods. New multivariable equations for patients with CVD were developed and demonstrated better accuracy, indicating that this methodology may be a valid alternative when CPET is unavailable.

Effects of Low- and High-Frequency Cardiac Rehabilitation on Risk Factors, Physical Fitness and Quality of Life in Middle-Aged Women with Coronary Heart Disease

Cardiac rehabilitation (CR) is a system that comprehensively manages risk factors to reduce the recurrence rate after cardiovascular disease treatment. This study compared the effects of home-based low-frequency CR (1-2 times/week) and center-based high-frequency CR (3-5 times/week) for 12 weeks. This study was conducted as an observational case-control study. Ninety women, ages 45 to 60, who underwent coronary artery stenting were enrolled. Measurement variables were waist circumference, body mass index (BMI), blood pressure (BP), total cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDLC), triglycerides (TG), glucose, VO₂ peak, body composition, and quality of life. Significant changes were observed in systolic BP, TC, LDLC, TG, VO₂ peak, exercise duration, and quality of life in both groups. However, BMI, waist circumference, body fat percentage, HDLC, and blood glucose only exhibited significant changes with HFT. The interaction effects according to time and group were as follows: systolic BP, waist circumference, body fat, BMI, HDLC, and glucose (p < 0.05). Therefore, in CR participants, HFT improved more than LFT on obesity factors, HDLC, and glucose change. As well as center-based HFT, home-based LFT also improved risk factors for cardiovascular disease, fitness, and quality of life. For female patients who have difficulty visiting the CR center frequently, home-based LFT may be a CR program that can be presented as an alternative.

Long-Term Maintenance of Cardiorespiratory Fitness Gains After Cardiac Rehabilitation Reduces Mortality Risk in Patients With Multimorbidity

PURPOSE

The objective of this study was to characterize the impact of multimorbidity and cardiorespiratory fitness (CRF) on mortality in patients completing cardiac rehabilitation (CR).

METHODS

This cohort study included data from patients with a history of cardiovascular disease (CVD) completing a 12-wk CR program between January 1996 and March 2016, with follow-up through March 2017. Patients were stratified by the presence of multimorbidity, which was defined as having a diagnosis of ≥2 noncommunicable diseases (NCDs). Cox regression analyses were used to evaluate the effects of multimorbidity and CRF on mortality in patients completing CR. Symptom-limited exercise tests were completed at baseline, immediately following CR (12 wk), with a subgroup completing another test at 1-yr follow-up. Peak metabolic equivalents (METs) were determined from treadmill speed and grade.

RESULTS

Of the 8320 patients (61 ± 10 yr, 82% male) included in the analyses, 5713 (69%) patients only had CVD diagnosis, 2232 (27%) had CVD+1 NCD, and 375 (4%) had CVD+≥2 NCDs. Peak METs at baseline (7.8 ± 2.0, 6.9 ± 2.0, 6.1 ± 1.9 METs), change in peak METs immediately following CR (0.98 ± 0.98, 0.83 ± 0.95, 0.76 ± 0.95 METs), and change in peak METs 1 yr after CR (0.98 ± 1.27, 0.75 ± 1.17, 0.36 ± 1.24 METs) were different ( P < .001) among the subgroups. Peak METs at 12 wk and the presence of coexisting conditions were each predictors ( P < .001) of mortality. Improvements in CRF by ≥0.5 METS from baseline to 1-yr follow-up among patients with or without multimorbidity were associated with lower mortality rates.

CONCLUSION

Increasing CRF by ≥0.5 METs improves survival regardless of multimorbidity status.

Technology-based Comprehensive Cardiac Rehabilitation Therapy (TaCT) for women with cardiovascular disease in a middle-income setting: A randomized controlled trial protocol

Women are underrepresented in cardiac rehabilitation (CR) despite the benefits, and this is exacerbated in lower-resource settings where CR is insufficiently available. In this randomized controlled trial, the effectiveness of the Technology-based Comprehensive Cardiac Rehabilitation Therapy (TaCT) electronic cardiac rehabilitation (eCR) intervention on functional capacity, risk factors, quality of life, heart-health behaviors, symptoms, and morbidity will be tested among women with CVD in a middle-income country. Following a pilot study, a single-center, single-blinded, 2 parallel-arm (1:1 SNOSE) superiority trial comparing an eCR intervention (TaCT) to usual care, with assessments pre-intervention and at 3 and 6 months will be undertaken. One hundred adult women will be recruited. Permuted block (size 10) randomization will be applied. The 6-month intervention comprises an app, website, SMS texts with generic heart-health management advice, and bi-weekly 1:1 telephone calls with a nurse trainee. Individualized exercise prescriptions will be developed based on an Incremental Shuttle Walk Test (primary outcome) and dietary plans based on 24 h dietary recall. A yoga/relaxation video will be provided via WhatsApp, along with tobacco cessation support and a moderated group chat. At 3 months, intervention engagement and acceptability will be assessed. Analyses will be conducted based on intent-to-treat. If results of this novel trial of women-focused eCR in a middle-income country demonstrate clinically-significant increases in functional capacity, this could represent an important development for the field considering this would be an important outcome for women and would translate to lower mortality.

Reference Standards for Peak Rating of Perceived Exertion during Cardiopulmonary Exercise Testing: Data from FRIEND

INTRODUCTION

Peak rating of perceived exertion (RPE) is measured during clinical cardiopulmonary exercise testing (CPX) and is commonly used as a subjective indicator of maximal effort. However, no study to date has reported reference standards or the distribution of peak RPE across a large cohort of apparently healthy individuals.

PURPOSE

This study aimed to determine reference standards for peak RPE when using the 6-20 Borg scale for both treadmill and cycle tests.

METHODS

The analysis included 9551 tests (8821 treadmill, 730 cycle ergometer) from 13 laboratories within the Fitness Registry and Importance of Exercise National Database (FRIEND). Using data from tests conducted January 1, 1980, to January 1, 2021, percentiles of peak RPE for men and women were determined for each decade from 20 to 89 yr of age for treadmill and cycle exercise modes. Two-way ANOVA was used to compare differences in peak RPE values between sexes and across age groups.

RESULTS

There were statistically significant differences in RPE between age groups whether the test was performed on a treadmill or cycle ergometer ( P < 0.05). However, the mean and median RPE for each sex, age group, and test mode were between 18 and 19. In addition, 83% of participants met the traditional RPE criteria of ≥18 for indicating sufficient maximal effort.

CONCLUSIONS

This report provides the first normative reference standards for peak RPE in both male and female individuals performing CPX on a treadmill or cycle ergometer. Furthermore, these reference standards highlight the general consistency of peak RPE responses during CPX.

What has cardiac rehabilitation looked like in the COVID-19 pandemic: Lessons learned for the future

The global coronavirus disease 2019 (COVID-19) pandemic prompted widespread national shutdown, halting or dramatically reducing the delivery of non-essential outpatient services including cardiac rehabilitation (CR). Center-based CR services were closed for as few as two weeks to greater than one year and the uncertainty surrounding the duration of the lockdown phase prompted programs to consider programmatic adaptations that would allow for the safe and effective delivery of CR services. Among the actions taken to accommodate in person CR sessions included increasing the distance between exercise equipment and/or limiting the number of patients per session. Legislative approval of reimbursing telehealth or virtual services presented an opportunity to reach patients that may otherwise have not considered attending CR during or even before the pandemic. Additionally, the considerable range of symptoms and infection severity as well as the risk of developing long lasting, debilitating symptoms has complicated exercise recommendations. Important lessons from publications reporting findings from clinical settings have helped shape the way in which exercise is applied, with much more left to discover. The overarching aim of this paper is to review how programs adapted to the COVID-19 pandemic and identify lessons learned that have positively influenced the future of CR delivery.

Novel Therapeutics for Type 2 Diabetes, Obesity, and Heart Failure: A REVIEW AND PRACTICAL RECOMMENDATIONS FOR CARDIAC REHABILITATION

BACKGROUND

Cardiac rehabilitation (CR) has evolved over time not only to improve cardiorespiratory fitness through exercise but also to promote lifestyle-related behaviors to manage cardiovascular disease risk factors. Given the prevalence of obesity, diabetes mellitus, metabolic syndrome, and heart failure, CR serves as an ideal setting to monitor and, when indicated, intervene to ensure that individuals are optimally treated.

PURPOSE

The objective of this report was to review current antihyperglycemic agents and discuss the role for these medications in the care and treatment of individuals participating in CR.

CONCLUSION

There is strong evidence that the benefits provided by some antihyperglycemic medications go beyond glycemic control to include general cardiovascular disease risk reduction. Health care professionals in CR should be aware of the cardiovascular benefits of newer antihyperglycemic agents, as well as the treatment approach to patients with type 2 diabetes, obesity, and heart failure.

Physical activity, cardiorespiratory fitness, and cardiovascular health: A clinical practice statement of the American Society for Preventive Cardiology Part II: Physical activity, cardiorespiratory fitness, minimum and goal intensities for exercise training, prescriptive methods, and special patient populations

The prescription of exercise for individuals with and without cardiovascular disease (CVD) should be scientifically-based yet adapted to the patient. This scientific statement reviews the clinical and physiologic basis for the prescription of exercise, with specific reference to the volume of physical activity (PA) and level of cardiorespiratory fitness (CRF) that confer significant and optimal cardioprotective benefits. Recommendations are provided regarding the appropriate intensity, frequency, and duration of training; the concept of MET-minutes per week; critical components of the exercise session (warm-up, conditioning phase, cool-down); methodologies for establishing the training intensity, including oxygen uptake reserve (V̇O2R), target heart rate derivation and rating perceived exertion; minimum and goal intensities for exercise training; and, types of training activities, including resistance training, adjunctive lifestyle PA, marathon/triathlon training, and high-intensity interval training. In addition, we discuss the rationale for and value of exercise training programs for patients with peripheral artery disease, diabetes mellitus, and heart failure.

Women-Focused Cardiovascular Rehabilitation: An International Council of Cardiovascular Prevention and Rehabilitation Clinical Practice Guideline

Women-focused cardiovascular rehabilitation (CR; phase II) aims to better engage women, and might result in better quality of life than traditional programs. This first clinical practice guideline by the International Council of Cardiovascular Prevention and Rehabilitation (ICCPR) provides guidance on how to deliver women-focused programming. The writing panel comprised experts with diverse geographic representation, including multidisciplinary health care providers, a policy-maker, and patient partners. The guideline was developed in accordance with Appraisal of Guidelines for Research and Evaluation (AGREE) II and the Reporting Items for practice Guidelines in HealTh care (RIGHT). Initial recommendations were on the basis of a meta-analysis. These were circulated to a Delphi panel (comprised of corresponding authors from review articles and of programs delivering women-focused CR identified through ICCPR's audit; N = 76), who were asked to rate each on a 7-point Likert scale in terms of impact and implementability (higher scores positive). A Web call was convened to achieve consensus; 15 panelists confirmed strength of revised recommendations (Grading of Recommendations Assessment, Development, and Evaluation [GRADE]). The draft underwent external review from CR societies internationally and was posted for public comment. The 14 drafted recommendations related to referral (systematic, encouragement), setting (model choice, privacy, staffing), and delivery (exercise mode, psychosocial, education, self-management empowerment). Nineteen (25.0%) survey responses were received. For all but 1 recommendation, ≥ 75% voted to include; implementability ratings were < 5/7 for 4 recommendations, but only 1 for effect. Ultimately 1 recommendation was excluded, 1 separated into 2 and all revised (2 substantively); 1 recommendation was added. Overall, certainty of evidence for the final recommendations was low to moderate, and strength mostly strong. These recommendations and associated tools can support all programs to feasibly offer some women-focused programming.

Individualized exercise prescription and cardiac rehabilitation following a spontaneous coronary artery dissection or aortic dissection

Aims

Prescribed aerobic-based exercise training is a low-risk fundamental component of cardiac rehabilitation (CR). Secondary prevention therapeutic strategies following a spontaneous coronary artery dissection (SCAD) or aortic dissection (AD) should include CR. Current exercise guidance for post-dissection patients recommends fundamental training components including target heart rate zones are not warranted. Omitting fundamental elements from exercise prescriptions risks safety and makes it challenging for both clinicians and patients to understand and implement recommendations in real-world practice. We review the principles of exercise prescription for CR, focusing on translating guidelines and evidence from well-studied high-risk CR populations to support the recommendation that exercise testing and individualized exercise prescription are important for patients following a dissection.

Methods and results

When patients self-perceive exercise intensity there is a tendency to underestimate intensities within metabolic domains that should be strictly avoided during routine exercise training following a dissection. However, exercise testing associated with CR enrolment has gained support and has not been linked to adverse events in optimally medicated post-dissection patients. Graded heart rate and blood pressure responses recorded throughout exercise testing provide key information for developing an exercise prescription. An exercise prescription that is reflective of medical history, medications, and cardiorespiratory fitness optimizes patient safety and yields improvements in blood pressure control and cardiorespiratory fitness, among other benefits.

Conclusion

This clinical practice and education article demonstrates how to develop and manage a CR exercise prescription for post-acute dissection patients that can be safe and effective for maintaining blood pressure control and improving cardiorespiratory fitness pre-post CR.

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.

Heart Failure in Cardiac Rehabilitation: A REVIEW AND PRACTICAL CONSIDERATIONS

PURPOSE

Exercise cardiac rehabilitation (CR) represents an evidence-based therapy for patients with heart failure with reduced ejection fraction (HFrEF) and this article provides a concise review of the relevant exercise testing and CR literature, including aspects unique to their care.

CLINICAL CONSIDERATIONS

A hallmark feature of HFrEF is exercise intolerance (eg, early-onset fatigue). Drug therapies for HFrEF target neurohormonal pathways to blunt negative remodeling of the cardiac architecture and restore favorable loading conditions. Guideline drug therapy includes β-adrenergic blocking agents; blockade of the renin-angiotensin system; aldosterone antagonism; sodium-glucose cotransport inhibition; and diuretics, as needed.

EXERCISE TESTING AND TRAINING

Various assessments are used to quantify exercise capacity in patients with HFrEF, including peak oxygen uptake measured during an exercise test and 6-min walk distance. The mechanisms responsible for the exercise intolerance include abnormalities in ( a ) central transport (chronotropic response, stroke volume) and ( b ) the diffusion/utilization of oxygen in skeletal muscles. Cardiac rehabilitation improves exercise capacity, intermediate physiologic measures (eg, endothelial function and sympathetic nervous system activity), health-related quality of life (HRQoL), and likely clinical outcomes. The prescription of exercise in patients with HFrEF is generally similar to that for other patients with cardiovascular disease; however, patients having undergone an advanced surgical therapy do present with features that require attention.

SUMMARY

Few patients with HFrEF enroll in CR and as such, many miss the derived benefits, including improved exercise capacity, a likely reduction in risk for subsequent clinical events (eg, rehospitalization), improved HRQoL, and adoption of disease management strategies.

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.

Clinician approach to cardiopulmonary exercise testing for exercise prescription in patients at risk of and with cardiovascular disease

Exercise training is highly recommended in current guidelines on primary and secondary prevention of cardiovascular disease (CVD). This is based on the cardiovascular benefits of physical activity and structured exercise, ranging from improving the quality of life to reducing CVD and overall mortality. Therefore, exercise should be treated as a powerful medicine and critical component of the management plan for patients at risk for or diagnosed with CVD. A tailored approach based on the patient's personal and clinical characteristics represents a cornerstone for the benefits of exercise prescription. In this regard, the use of cardiopulmonary exercise testing is well-established for risk stratification, quantification of cardiorespiratory fitness and ventilatory thresholds for a tailored, personalised exercise prescription. The aim of this paper is to provide a practical guidance to clinicians on how to use data from cardiopulmonary exercise testing towards personalised exercise prescriptions for patients at risk of or with CVD.

Effect of Cardiac Rehabilitation on Glomerular Filtration Rate Using Serum Cystatin C Concentration in Patients With Cardiovascular Disease and Renal Dysfunction

PURPOSE

Among patients with chronic kidney disease (CKD), little is known about whether the effect of cardiac rehabilitation (CR) on renal function differs across baseline estimated glomerular filtration rate using the serum concentration of cystatin C (eGFRcys). The aim of this study was to evaluate the effect of CR on renal function in patients with CKD.

METHODS

We performed a retrospective cohort study of patients with CKD (15 ≤ eGFRcys < 60 mL/min/1.73 m2) who participated in our CR program for cardiovascular disease. First, the patients were divided into three groups according to the baseline severity of the eGFRcys: G3a, G3b, and G4 groups. We compared the eGFRcys before and after the CR in each group. Second, to determine the association of baseline eGFRcys with the effect of CR, we fitted a linear regression model using the percent change in the eGFRcys (%ΔeGFRcys) as an outcome.

RESULTS

Of the 203 patients, 122 were in G3a, 60 were in G3b, and 21 were in G4 groups. The mean improvement of eGFRcys in each group was 1.3, 3.1, and 4.8 mL/min/1.73 m2, respectively. The %ΔeGFRcys was larger among patients with lower baseline eGFRcys (0.47% greater improvement of %ΔeGFRcys/one lower baseline eGFRcys; 95% CI, 0.23-0.72%). This association remained significant after adjustment for potential confounders (0.63% greater improvement of %ΔeGFRcys/one lower baseline eGFRcys; 95% CI, 0.35-0.91%).

CONCLUSIONS

The effect of CR on renal function was greater in patients with worse renal dysfunction measured by eGFRcys. A CR program could be useful for patients with severe renal dysfunction and it might have a beneficial effect on their renal function.

Exercise intensity assessment and prescription in cardiovascular rehabilitation and beyond: why and how: a position statement from the Secondary Prevention and Rehabilitation Section of the European Association of Preventive Cardiology

A proper determination of the exercise intensity is important for the rehabilitation of patients with cardiovascular disease (CVD) since it affects the effectiveness and medical safety of exercise training. In 2013, the European Association of Preventive Cardiology (EAPC), together with the American Association of Cardiovascular and Pulmonary Rehabilitation and the Canadian Association of Cardiac Rehabilitation, published a position statement on aerobic exercise intensity assessment and prescription in cardiovascular rehabilitation (CR). Since this publication, many subsequent papers were published concerning the determination of the exercise intensity in CR, in which some controversies were revealed and some of the commonly applied concepts were further refined. Moreover, how to determine the exercise intensity during resistance training was not covered in this position paper. In light of these new findings, an update on how to determine the exercise intensity for patients with CVD is mandatory, both for aerobic and resistance exercises. In this EAPC position paper, it will be explained in detail which objective and subjective methods for CR exercise intensity determination exist for aerobic and resistance training, together with their (dis)advantages and practical applications.

Exercise training in cardiac rehabilitation: Setting the right intensity for optimal benefit

Cardiac rehabilitation (CR) programs are recommended standard-of-care by all major cardiovascular medicine professional organizations. Exercise training is the cornerstone for CR, with aerobic training being the primary form of training. The benefits of exercise training are multiple; however, improved cardiorespiratory fitness is of utmost importance. Moderate-intensity continuous training, supplemented with resistance training, has traditionally been the most common form of exercise training in CR. This review discusses the role of aerobic exercise training in CR and the importance of effective and personalized exercise prescription for optimized results. We also focus on the benefits and utility of high-intensity interval training across different clinical populations commonly seen in the CR setting.

Total body recumbent stepping vs treadmill walking in supervised exercise therapy: A pilot study

Background: Treadmill walking is the most commonly recommended exercise modality in supervised exercise therapy (SET) for peripheral artery disease (PAD); however, other modalities may be equally effective and more tolerable for patients. The primary aim of this single-blind, randomized pilot study was to compare the feasibility, safety, and preliminary efficacy of a treadmill walking (TM) versus a total body recumbent stepping (TBRS) exercise program for treatment of PAD. Methods: Participants (n = 19) enrolled in a 12-week SET program and were randomized to either a TM (n = 9) or TBRS (n = 10) exercise group that followed current SET exercise guidelines. Feasibility, safety, and efficacy outcomes were assessed. Results: SET attendance was 86% and 71%, respectively, for TBRS and TM groups (p = 0.07). Session exercise dose (metabolic equivalents of task [MET] minutes) (mean [SD]) for TM was 117.6 [27.4] compared to 144.7 [28.7] in the TBRS group (p = 0.08). Study-related adverse events were nine in 236 training hours and three in 180 training hours for the TBRS and TM groups, respectively. There were no significant differences between groups for improvement in 6-minute walk distance (mean [SD]) (TM: 133.2 ft [53.5] vs TBRS: 154.8 ft [49.8]; p = 0.77) after adjusting for baseline 6-minute walk distance. Conclusion: This is the first randomized study comparing TBRS to TM exercise in SET using current SET guidelines. This pilot study showed that TBRS is a feasible and safe exercise modality in SET. This study provides preliminary efficacy of the use of TBRS exercise in SET programs following current guidelines. Larger studies should be conducted to confirm these findings.

New Formula to Predict Heart Rate at Anaerobic Threshold That Considers the Effects of β-Blockers in Patients With Myocardial Infarction: MULTI-INSTITUTIONAL RETROSPECTIVE CROSS-SECTIONAL STUDY

PURPOSE

It is recommended that patients with myocardial infarction (MI) be prescribed exercise by target heart rate (HR) at the anaerobic threshold (AT) via cardiopulmonary exercise testing (CPX). Although percent HR reserve using predicted HRmax (%HRRpred) is used to prescribe exercise if CPX or an exercise test cannot be performed, %HRRpred is especially difficult to use when patients take β-blockers. We devised a new formula to predict HR at AT (HRAT) that considers β-blocker effects in MI patients and validated its accuracy.

METHODS

The new formula was created using the data of 196 MI patients in our hospital (derivation sample), and its accuracy was assessed using the data of 71 MI patients in other hospitals (validation sample). All patients underwent CPX 1 mo after MI onset, and resting HR, resting systolic blood pressure (SBP), and HRAT were measured during CPX.

RESULTS

The results of multiple regression analysis in the derivation sample gave the following formula (R2 = 0.605, P < .001): predicted HRAT = 2.035 × (≥65 yr:-1, <65 yr:1) + 3.648 × (body mass index <18.5 kg/m2:-1, body mass index ≥18.5 kg/m2:1) + 4.284 × (β1-blocker(+):-1, β1-blocker(-):1) + 0.734 × (HRrest) + 0.078 × (SBPrest) + 36.812. This formula consists entirely of predictors that can be obtained at rest. HRAT and predicted HRAT with the new formula were not significantly different in the validation sample (mean absolute error: 5.5 ± 4.1 bpm).

CONCLUSIONS

The accuracy of the new formula appeared to be favorable. This new formula may be a practical method for exercise prescription in MI patients, regardless of their β-blocker treatment status, if CPX is unavailable.

Exercise ECG Testing and Stress Cardiac Magnetic Resonance for Risk Prediction in Patients With Chronic Coronary Syndrome

PURPOSE

Vasodilator stress cardiac magnetic resonance (VS-CMR) has become crucial in the workup of patients with known or suspected chronic coronary syndrome (CCS). Whether traditional exercise ECG testing (ExECG) contributes prognostic information beyond VS-CMR is unclear.

METHODS

We retrospectively included 288 patients with known or suspected CCS who had undergone ExECG and subsequent VS-CMR in our institution. Clinical, ExECG, and VS-CMR variables were recorded. We defined the serious adverse events (SAE) as a combined endpoint of acute coronary syndrome, admission for heart failure, or all-cause death.

RESULTS

During a mean follow-up of 4.2 ± 2.15 yr, we registered 27 SAE (15 admissions for acute coronary syndrome, eight admissions for heart failure, and four all-cause deaths). Once adjusted for clinical, ExECG, and VS-CMR parameters associated with SAE, the only independent predictors were HRmax in ExECG (HR = 0.98: 95% CI, 0.96-0.99; P = .01) and more extensive stress-induced perfusion defects (PDs, number of segments) in VS-CMR (HR = 1.19: 95% CI, 1.07-1.34; P < .01). Adding HRmax significantly improved the predictive power of the multivariable model for SAE, including PDs (continuous reclassification improvement index: 0.47: 95% CI, 0.10-0.81; P < .05). The annualized SAE rate was 1% (if PD < 2 segments and HRmax > 130 bpm), 2% (if PD < 2 segments and HRmax ≤ 130 bpm), 3.2% (if PD ≥ 2 segments and HRmax > 130 bpm), and 6.3% (if PD ≥ 2 segments and HRmax ≤ 130 bpm), P < .01, for the trend. In patients on β-blocker therapy, however, only PDs in VS-CMR, but not HRmax, predicted SAE.

CONCLUSIONS

We conclude that ExECG contributes significantly to prognostic information beyond VS-CMR in patients with known or suspected CCS.

High level physical activity in cardiac rehabilitation: Implications for exercise training and leisure-time pursuits

IMPORTANCE

Regular moderate-to-vigorous physical activity and increased levels of cardiorespiratory fitness (CRF) are widely promoted as cardioprotective measures in secondary prevention interventions.

OBSERVATIONS

A low level of CRF increases the risk of cardiovascular disease (CVD) to a greater extent than merely being physically inactive. An exercise capacity <5 metabolic equivalents (METs), generally corresponding to the bottom 20% of the fitness continuum, indicates a higher mortality group. Accordingly, a key objective in early cardiac rehabilitation (CR) is to increase the intensity of training to >3 METs, to empower patients to vacate this "high risk" group. Moreover, a "good" exercise capacity, expressed as peak METs, identifies individuals with a favorable long-term prognosis, regardless of the underlying extent of coronary disease. On the other hand, vigorous-to-high intensity physical activity, particularly when unaccustomed, and some competitive sports are associated with a greater incidence of acute cardiovascular events. Marathon and triathlon training/competition also have limited applicability and value in CR, are associated with acute cardiac events each year, and do not necessarily provide immunity to the development of or the progression of CVD. Furthermore, extreme endurance exercise regimens are associated with an increased incidence of atrial fibrillation and accelerated coronary artery calcification.

CONCLUSIONS AND RELEVANCE

High-intensity training offers a time-saving alternative to moderate intensity continuous training, as well as other potential advantages. Additional long-term studies assessing safety, adherence, and morbidity and mortality are required before high-intensity CR training can be more widely recommended, especially in previously sedentary patients with known or suspected CVD exercising in non-medically supervised settings.

Cardiac rehabilitation for heart transplant patients: Considerations for exercise training

Heart transplantation (HT) is the treatment of choice for eligible patients with end-stage chronic heart failure (HF). One-year survival world-wide is >85%. Many patients experience a reasonable functional ability post-HT, but episodes of acute rejection, as well as multiple co-morbidities such as hypertension, diabetes, chronic kidney disease and cardiac allograft vasculopathy are common. Immunosuppression with prednisone frequently results in increased body fat and skeletal muscle atrophy. Exercise capacity is below normal for most patients with a mean peak oxygen uptake (VO₂) of approximately 60% of expected. HT recipients have abnormal exercise physiology findings related to surgical cardiac denervation, diastolic dysfunction, and the legacy of reduced skeletal muscle oxidative capacity and impaired vasodilatory ability resulting from pre-HT chronic HF. The heart rate response to exercise is blunted. Cardiac reinnervation resulting in partial normalization of the heart rate response to exercise occurs in approximately 40% of HT recipients months to years after HT. Supervised exercise training in cardiac rehabilitation (CR) programs is safe and is recommended by professional societies both before (pre-habilitation) and after HT. Exercise training does not require alteration in immunosuppressants. Exercise training in adults after HT improves peak VO₂ and skeletal muscle strength. It has also been demonstrated to reduce the severity of cardiac allograft vasculopathy. In addition, CR exercise training is associated with reduced stroke risk, percutaneous coronary intervention, hospitalization for either acute rejection or HF, and death. There are only limited data for exercise training in the pediatric population.

Cognition and Exercise: GENERAL OVERVIEW AND IMPLICATIONS FOR CARDIAC REHABILITATION

Performance of endurance exercise is associated with a broad range of cognitive benefits, with notable improvements shown across a wide variety of populations including healthy populations as well as those with impaired cognition. By examining the effects of exercise in general populations, as well in populations where cognitive deficits are pronounced, and critical to self-care, we can learn more about using exercise to ameliorate cognitive issues and apply that knowledge to other patient populations, such as those eligible for cardiac rehabilitation (CR). Cognitive challenges are a concern within CR, as management of a chronic disease is cognitively taxing, and, as expected, deficits in cognition predict worse outcomes, including lower attendance at CR. Some subsets of patients within CR may be particularly at high risk for cognitive challenges including those with heart failure with low ejection fraction, recent coronary bypass surgery, multiple chronic conditions, and patients of lower socioeconomic status. Attendance at CR is associated with cognitive gains, likely through the progressive exercise component, with larger amounts of exercise over longer periods having greater benefits. Programs should identify at-risk patients, who could gain the most from completing CR, and provide additional support to keep those patients engaged. While engaged in CR, patients should be encouraged to exercise, at least at moderate intensity, and transitioned to a long-term exercise regimen. Overall, CR programs are well-positioned to support these patients and make significant contributions to their long-term well-being.

Making Cardiopulmonary Exercise Testing Interpretable for Clinicians

ABSTRACT

Cardiopulmonary exercise testing (CPET) is a dynamic clinical tool for determining the cause for a person's exercise limitation. CPET provides clinicians with fundamental knowledge of the coupling of external to internal respiration (oxygen and carbon dioxide) during exercise. Subtle perturbations in CPET parameters can differentiate exercise responses among individual patients and disease states. However, perhaps because of the challenges in interpretation given the amount and complexity of data obtained, CPET is underused. In this article, we review fundamental concepts in CPET data interpretation and visualization. We also discuss future directions for how to best use CPET results to guide clinical care. Finally, we share a novel three-dimensional graphical platform for CPET data that simplifies conceptualization of organ system-specific (cardiac, pulmonary, and skeletal muscle) exercise limitations. Our goal is to make CPET testing more accessible to the general medical provider and make the test of greater use in the medical toolbox.

Optimizing Outcomes in Cardiac Rehabilitation: The Importance of Exercise Intensity

Exercise based cardiac rehabilitation (CR) is recognized internationally as a class 1 clinical practice recommendation for patients with select cardiovascular diseases and heart failure with reduced ejection fraction. Over the past decade, several meta-analyses have generated debate regarding the effectiveness of exercise-based CR for reducing all-cause and cardiovascular mortality. A common theme highlighted in these meta-analyses is the heterogeneity and/or lack of detail regarding exercise prescription methodology within CR programs. Currently there is no international consensus on exercise prescription for CR, and exercise intensity recommendations vary considerably between countries from light-moderate intensity to moderate intensity to moderate-vigorous intensity. As cardiorespiratory fitness [peak oxygen uptake (VO₂peak)] is a strong predictor of mortality in patients with coronary heart disease and heart failure, exercise prescription that optimizes improvement in cardiorespiratory fitness and exercise capacity is a critical consideration for the efficacy of CR programming. This review will examine the evidence for prescribing higher-intensity aerobic exercise in CR, including the role of high-intensity interval training. This discussion will highlight the beneficial physiological adaptations to pulmonary, cardiac, vascular, and skeletal muscle systems associated with moderate-vigorous exercise training in patients with coronary heart disease and heart failure. Moreover, this review will propose how varying interval exercise protocols (such as short-duration or long-duration interval training) and exercise progression models may influence central and peripheral physiological adaptations. Importantly, a key focus of this review is to provide clinically-relevant recommendations and strategies to optimize prescription of exercise intensity while maximizing safety in patients attending CR programs.

Cardio-Oncology Rehabilitation (CORE) Exercise Prescription and Programming: A PRACTICAL GUIDE

BACKGROUND

Patients with cancer almost universally report diminished health-related quality of life. Many patients experience persistent fatigue and most have below-average exercise capacities. Despite the publication of exercise guidelines for cancer survivors that encourage physical activity, few patients exercise on a regular basis. Cardiovascular disease is a major cause of death in early-stage malignancies. Exercise training has been demonstrated to decrease cardiovascular events in patients with cancer. In addition, regular exercise improves exercise capacity, reduces fatigue, and improves quality of life in cancer survivors.

CLINICAL CONSIDERATIONS

A 2019 American Heart Association scientific statement, endorsed by the American Cancer Society, provided a framework and rationale for partnering with existing multidimensional, interdisciplinary outpatient cardiac rehabilitation programs to provide supervised exercise training and risk factor control services for patients with cancer and cancer survivors: cardio-oncology rehabilitation. In addition, the American College of Sports Medicine has published recommendations for cancer exercise training.

SUMMARY

This article provides practical suggestions for incorporating patients with cancer into cardiac rehabilitation and for patient-specific exercise prescription. Illustrative patient case examples are provided.

Prioritizing movement to address the frailty phenotype in heart failure

Frailty is a highly prevalent multisystem syndrome in older adults with heart failure (HF) and is associated with poor clinical prognosis and increased complexity of care. While frailty is neither disease nor age specific, it is a clinical manifestation of aging-related processes that reflects a reduced physiological ability to tolerate and recover from stress associated with aging, disease, or therapy. Within this context, physical frailty, which is distinctly oriented to physical functional domains (e.g., muscle weakness, slowness, and low activity), has been recognized as a critical vital sign in older persons with HF. Identification and routine assessment of physical frailty, using objective physical performance measures, may guide the course of patient-centered treatment plans that maximize the likelihood of improving clinical outcomes in older HF patients. Exercise-based rehabilitation is a primary therapy to improve cardiovascular health in patients with HF; however, the limited evidence supporting the effectiveness of exercise tailored to older and frail HF patients underscores the current gaps in management of their care. Interdisciplinary exercise interventions designed with consideration of physical frailty as a therapeutic target may be an important strategy to counteract functional deficits characteristic of frailty and HF, and to improve patient-centered outcomes in this population. The purpose of this current review is to provide a better understanding of physical frailty and its relation to management of care in older patients with HF. Implications of movement-based interventions, including exercise and physical rehabilitation, to prevent or reverse physical frailty and improve clinical outcomes will further be discussed.

Chronotropic Responses to Exercise and Recovery in Myocardial Infarction Patients Taking β-Blockers Following Aerobic High-Intensity Interval Training: AN INTERFARCT STUDY

PURPOSE

The objectives of this study were to compare the effects of two different high-intensity interval training (HIIT) programs (low-volume vs high-volume) on chronotropic responses during exercise and recovery, and to contrast the results of the HIIT groups together to only physical activity recommendations in post-myocardial infarction (MI) patients taking β-blockers.

METHODS

Resting heart rate (HRrest), peak HR (HRpeak), HR reserve (HRreserve = HRpeak-HRrest), HR recovery (HRR) as the difference between HRpeak and post-exercise HR, and chronotropic incompetence were assessed in 70 patients (58 ± 8 yr) following MI with a cardiopulmonary exercise test to peak exertion before and after a 16-wk exercise intervention period. All participants were randomized to either attention control (AC) (physical activity recommendations) or one of the two supervised HIIT groups (2 d/wk).

RESULTS

After the intervention, no significant between-HIIT group differences were observed. The HRpeak increased (P < .05) in low- (Δ= 8 ± 18%) and high-volume HIIT (Δ= 6 ± 9%), with a small decrease in AC (Δ=- 2 ± 12%, P > .05) resulting in large differences (P < .05) between HIIT and AC. The HRreserve increased (P < .05) in high-volume HIIT. The HRR slightly increased (P < .05) in low-volume (5th min, Δ= 19 ± 31%) and high-volume HIIT (2nd min, Δ= 15 ± 29%, and 5th min, Δ= 19 ± 28%).

CONCLUSION

These findings suggest that both low- and high-volume HIIT elicit similar improvements in chronotropic responses after MI, independent of β-blocker treatment. Supervised HIIT was more effective than giving physical activity recommendations alone. Low-volume HIIT is presented as a potent and time-efficient exercise strategy that could enhance the sympathovagal balance in this population.

Evaluating Exercise Progression in an Australian Cardiac Rehabilitation Program: Should Cardiac Intervention, Age, or Physical Capacity Be Considered?

Progression of prescribed exercise is important to facilitate attainment of optimal physical capacity during cardiac rehabilitation. However, it is not clear how often exercise is progressed or to what extent. This study evaluated whether exercise progression during clinical cardiac rehabilitation was different between cardiovascular treatment, age, or initial physical capacity. The prescribed exercise of sixty patients who completed 12 sessions of outpatient cardiac rehabilitation at a major Australian metropolitan hospital was evaluated. The prescribed aerobic exercise dose was progressed using intensity rather than duration, while repetitions and weight lifted were utilised to progress resistance training dose. Cardiovascular treatment or age did not influence exercise progression, while initial physical capacity and strength did. Aerobic exercise intensity relative to initial physical capacity was progressed from the first session to the last session for those with high (from mean (95%CI) 44.6% (42.2-47.0) to 68.3% (63.5-73.1); p < 0.001) and moderate physical capacity at admission (from 53.0% (50.7-55.3) to 76.3% (71.2-81.4); p < 0.001), but not in those with low physical capacity (from 67.3% (63.7-70.9) to 85.0% (73.7-96.2); p = 0.336). The initial prescription for those with low physical capacity was proportionately higher than for those with high capacity (p < 0.001). Exercise testing should be recommended in guidelines to facilitate appropriate exercise prescription and progression.

Prehabilitation Coming of Age: IMPLICATIONS FOR CARDIAC AND PULMONARY REHABILITATION

While cardiac and pulmonary rehabilitation programs traditionally involve exercise therapy and risk management following an event (eg, myocardial infarction and stroke), or an intervention (eg, coronary artery bypass surgery and percutaneous coronary intervention), prehabilitation involves enhancing functional capacity and optimizing risk profile prior to a scheduled intervention. The concept of prehabilitation is based on the principle that patients with higher functional capabilities will better tolerate an intervention, and will have better pre- and post-surgical outcomes. In addition to improving fitness, prehabilitation has been extended to include multifactorial risk intervention prior to surgery, including psychosocial counseling, smoking cessation, diabetes control, nutrition counseling, and alcohol abstinence. A growing number of studies have shown that patients enrolled in prehabilitation programs have reduced post-operative complications and demonstrate better functional, psychosocial, and surgery-related outcomes. These studies have included interventions such as hepatic transplantation, lung cancer resection, and abdominal aortic aneurysm (repair, upper gastrointestinal surgery, bariatric surgery, and coronary artery bypass grafting). Studies have also suggested that incorporation of prehabilitation before an intervention in addition to traditional rehabilitation following an intervention further enhances physical function, lowers risk for adverse events, and better prepares a patient to resume normal activities, including return to work. In this overview, we discuss prehabilitation coming of age, including key elements related to optimizing pre-surgical fitness, factors to consider in developing a prehabilitation program, and exercise training strategies to improve pre-surgical fitness.