Predictors of cardiorespiratory fitness improvement in phase II cardiac rehabilitation

Predictors of gain in exercise capacity through cardiac rehabilitation: Sex and age matter

BACKGROUND

Cardiac rehabilitation (CR) is a cornerstone of secondary prevention that improves cardiovascular outcomes. However, the determinants of treatment success are poorly understood.

OBJECTIVES

We investigated the associations of health-related quality of life (HRQoL), sex, age, employment status and housing situation with improvement in exercise capacity throughout CR.

METHODS

We analyzed data from 392 CR outpatients (81% men and 19% women). Exercise capacity at baseline and upon completion of the program was measured with the 6-minute walk distance (6MWD). HRQoL at CR entry was assessed with the Short Form 36 Health Survey (SF-36).

RESULTS

A multivariable regression analysis revealed that both men and women showed significant improvement in exercise capacity (p < .001). Female sex (B = 18.118, 95% CI 0.341 - 36.035, p = .046) and younger age (B = -0.887, 95% CI -1.463 - -0.312, p = .003) emerged as predictors of greater improvement, while HRQoL, employment status, and housing situation were not associated with significant change in exercise capacity. The final model explained 25% of the variance in exercise capacity change (adjusted R2 = 0.25, p < .001).

CONCLUSIONS

Our results indicate that women and younger participants benefit from CR by improving their exercise capacity. Employment status, housing situation and HRQoL showed no effects on CR outcome.

An evaluation of the role of the exercise training dose for changes in exercise capacity following a standard cardiac rehabilitation program

BACKGROUND

To retrospectively characterize and compare the dose of exercise training (ET) within a large cohort of patients demonstrating different levels of improvement in exercise capacity following a cardiac rehabilitation (CR) program.

METHODS

A total of 2310 patients who completed a 12-week, center-based, guidelines-informed CR program between January 2018 and December 2019 were included in the analysis. Peak metabolic equivalents (MET_peak) were determined pre- and post-CR during which total duration (ET time) and intensity [percent of heart rate peak (%HR_peak)] of supervised ET were also obtained. Training responsiveness was quantified on the basis of changes in MET_peak from pre- to post-CR. A cluster analysis was performed to identity clusters demonstrating discrete levels of responsiveness (i.e., negative, low, moderate, high, and very-high). These were compared for several baseline and ET-derived variables which were also included in a multivariable linear regression model.

RESULTS

At pre-CR, baseline MET_peak was progressively lower with greater training responsiveness (F_(4,2305) = 44.2, P < 0.01, η²_p = 0.71). Likewise, average training duration (F_(4,2305) = 10.7 P < 0.01, η²_p = 0.02) and %HR_peak (F_(4,2305) = 25.1 P < 0.01, η²_p = 0.042) quantified during onsite ET sessions were progressively greater with greater training responsiveness. The multivariable linear regression model confirmed that baseline MET_peak, training duration and intensity during ET, BMI, and age (P < 0.001) were significant predictors of MET_peak post-CR.

CONCLUSIONS

Along with baseline MET_peak, delta BMI, and age, the dose of ET (i.e., training duration and intensity) predicts MET_peak at the conclusion of CR. A re-evaluation of current approaches for exercise intensity prescription is recommended to extend the benefits of completing CR to all patients.

Factors Associated With Participation Rate and Predictive of Improvement After Cardiac Rehabilitation in Patients With Heart Failure

PURPOSE

Patients with heart failure (HF) are often limited in their ability to perform exercise. Cardiac rehabilitation (CR) improves aerobic capacity and quality of life (QOL) and is recommended for patients with clinically stable HF; however, it is underutilized. The aim of this study was to investigate the factors associated with participation and completion rates and predictive of improvement after phase II CR in patients with HF.

METHODS

Participation and completion rates were calculated for all patients with HF enrolled in a multidisciplinary management program from October 2008 to December 2018. Functional capacity and QOL were estimated. In patients undergoing CR, changes in peak oxygen uptake (V˙ o2peak ) were measured.

RESULTS

Of 662 patients enrolled, 448 (68%) completed the cardiopulmonary exercise test (CPX). Phase II CR was recommended in 411 patients, of whom 291 (71%) participated in CR. Participation was significantly related to sex and the time interval in days between hospital discharge and the CPX. Overall, 171 patients completed 36 sessions of CR (with a completion rate of 59%). During CR, there were 18 (6%) adverse events. Cardiac rehabilitation was associated with improvement in V˙ o2peak from 1153 ± 393 to 1342 ± 470 mL/min (a 16% improvement; P < .001) and in QOL. The independent predictors of increase in V˙ o2peak included sex, age, diabetes mellitus, and entry V˙ o2peak .

CONCLUSIONS

In patients with HF, factors associated with CR participation rate included sex and days between hospital discharge and the CPX. Participation in CR improved V˙ o2peak and QOL. The improvement was related to male sex, younger age, no diabetes mellitus, and higher entry V˙ o2peak .

Yangxinshi Tablet Improves Exercise Capacity for Patients with Coronary Heart Disease: Results from a Randomized, Double-Blind, Placebo-Controlled, and Multicenter Trial

Objective

To assess the clinical effectiveness of Yangxinshi (YXS) tablets on exercise capacity and symptoms of anxiety and depression in patients with coronary heart disease (CHD).

Methods and Results

A randomized, double-blind, placebo-controlled, multicenter clinical trial was performed to assess the effects of YXS tablets on exercise capacity and quality of life in patients with CHD. A total of 82 patients were included in this trial. Compared with the placebo group, the YXS group showed significant improvement in peak VO 2 (0.22 L/min vs 0.01 L/min; difference 0.1, 95% confidence interval (CI) 0.04-0.16, p = 0.000), peak Mets (0.58 vs 0.09; difference 0.3, 95% CI 0.12-0.47, p = 0.005), anaerobic threshold (AT) VO 2 (0.23 L/min vs 0.04 L/min; difference 0.12, 95% CI 0.07-0.18, p = 0.000), AT Mets (0.62 vs 0.16; difference 0.35, 95% CI 0.2-0.5, p = 0.001), and 6 minutes walking test (6MWT) (50.05 m vs 11.91 m; difference 29.92, 95% CI 18.78-41.07, p = 0.000). There were no differences in Hamilton anxiety rating scale (HAM-A score (1.97 vs 2.07; difference 2.03, 95% CI 0.99-3.06, p = 0.926) and Hamilton depression rating scale (HAM-D) score (1.06 vs 1.7; difference1.42, 95% CI 0.24-2.6, p = 0.592).

Conclusions

In patients with CHD, YXS tablets, compared with placebo, could improve exercise capacity, without beneficial effects on anxiety and depression symptoms.

Mediator Effect of Cardiorespiratory Fitness on the Association between Physical Activity and Lung Function in Adults: Cross-Sectional Results from the Epimov Study

We investigated whether cardiorespiratory fitness (CRF) mediates the association between moderate-to-vigorous physical activity (MVPA) and lung function in asymptomatic adults. We examined the cross-sectional results of 1362 adults aged 18-80 years from the Epidemiology and Human Movement Study. Participants were submitted to spirometry to obtain forced vital capacity (FVC) and forced expiratory volume in 1s (FEV1). Additionally, we used cardiopulmonary exercise testing to obtain peak oxygen uptake (V˙O2) as a measure of CRF. Participants used a triaxial accelerometer for 4-7 days to obtain MVPA. Mediation analyses were performed considering the CRF as a mediator, MVPA as an independent variable, and FVC and FEV1 as dependent variables with adjustment for age, sex, and cardiovascular risk score. We aimed to investigate the total (path c) and direct (paths a, b, c') effects through the regression coefficients. We also examined the indirect effect, which was obtained from the product of the coefficients (path ab). Our sample was composed mainly of overweight and middle-aged women. MVPA was positively related to CRF (path a), as well as CRF and lung function (path b). MVPA also presented a significant positive total effect (path c) in the lung function. However, this relationship became non-significant when CRF was included in the model for both FVC and FEV1 (path c'). We did not observe a direct effect of MVPA on the lung function. In contrast, the indirect effect was significant (path ab). Lastly, CRF mediated 60% of the total effect of MVPA on FVC and 61.9% on FEV1. CRF mediates the relationship between lung function and MVPA in asymptomatic adults. Therefore, our results reinforce the need to include CRF assessment in practice clinical routine and suggest that strategies focusing on CRF might be more promising to prevent respiratory diseases in adults.

Predictors of completion and response to a psychological intervention to promote health behavior adherence in heart failure

OBJECTIVE

Most individuals with heart failure (HF) struggle to adhere to one or more health behaviors, and interventions to promote adherence are time-intensive and costly. In this analysis, we examined the predictors of engagement and response related to a telephone-delivered health behavior intervention for individuals with HF.

METHOD

Using data from two pilot trials (N = 25) of a behavioral intervention for individuals with New York Heart Association (NYHA) class I-II HF, we examined predictors of intervention engagement and response using linear and mixed effects regression analyses. Predictors included medical (NYHA class, physical health-related quality of life [HRQoL], and HF symptoms) and intervention (ease and usefulness/utility ratings of the first intervention exercise) characteristics. Outcomes included percentage of sessions completed, accelerometer-measured physical activity, and sodium intake.

RESULTS

Lower physical HRQoL and more frequent HF symptoms were associated with completion of more sessions. In contrast, more frequent HF symptoms and higher NYHA class were associated with less physical activity improvement. Finally, participants' ratings of the first session's utility were associated with greater improvements in physical activity at follow-up.

CONCLUSIONS

These findings suggest that while individuals with greater functional impairment are more engaged in a behavioral intervention, they may be less able to increase physical activity in response to the program. Furthermore, the perceived utility of an initial session may predict longer-term behavior change. Larger studies are needed to clarify the presence of additional predictors and determine how they can be used to better tailor health behavior interventions.

Indoor cycling training in rehabilitation of patients after myocardial infarction

BACKGROUND

Standard endurance training used from the second stage of cardiac rehabilitation has many common features with indoor cycling training which is used in fitness clubs. In the study, an attempt was made to evaluate the usefulness of this form of training in a 24-day rehabilitation program for patients after myocardial infarction. The study examined a group of 64 patients (51.34 ± 8.02 years) who were divided into two groups: the IC group (32 patients aged 53.40 ± 4.31 years) with indoor cycling training instead of standard endurance training; and the ST group (32 patients aged 55.31 ± 6.45 years) performing standard training. The level of exercise tolerance (cardiopulmonary exercise testing on a treadmill-Bruce's protocol), hemodynamic indicators of the left ventricle (echocardiography) and blood lipid profile (laboratory test) were assessed.

RESULTS

In the IC group there was a significant increase in the test duration (9.21 ± 2.02 vs 11.24 ± 1.26 min; p < 0.001), the MET value (9.16 ± 1.30 vs 10.73 ± 1.23; p = 0.006) and VO2max (37.27 ± 3.23 vs 39.10 ± 3.17 ml/kg/min; p < 0.001). Parallel changes were observed in the ST group, where the following parameters improved: the test duration (9.41 ± 0.39 vs 10.91 ± 2.22; p < 0.001), MET value (8.65 ± 0.25 vs 9.86 ± 1.12; p = 0.002) and VO2max (36.89 ± 6.22 vs 38.76 ± 3.44; p < 0.001). No statistically significant changes were found in the hemodynamic indices of the left ventricle and the lipid profile. Also, the intergroup analysis did not show any statistical significance.

CONCLUSION

Based on the research results, it was found that indoor cycling training in the second phase of cardiac rehabilitation is a safe form of therapy and therefore may be an interesting alternative method to the classic bicycle ergometer exercise in the stage of early cardiac rehabilitation.

Power walking based outpatient cardiac rehabilitation in patients with post-coronary angioplasty: Randomized control trial

PURPOSE

The purpose of this trial was to compare the effectiveness of standardized outpatient cardiac rehabilitation combined with treadmill power walking versus standardized outpatient cardiac rehabilitation alone on health-related quality of life (HQoL), functional exercise capacity (FEC), left ventricular ejection fraction (LVEF) and metabolic equivalent of tasks (METs) in patients who went post coronary angioplasty (CA). Further this study evaluated the association between average numbers of steps taken with above clinical outcomes.

METHODS

In a pragmatic sequential randomized clinical trial, 24 patients were randomized into two groups (n = 12) and participated in a standardized outpatient cardiac rehabilitation program (SOCRP) with treadmill power walking as an intervention group and SOCRP alone in control group. Scores obtained before and after 4 weeks of intervention, that is, after 12 treatment sessions were assessed using a HQoL questionnaire and 6-min walk test (6 MWT). Average number of steps taken throughout the 4 weeks, METs and LVEF values were obtained by pedometer, exercise stress testing and echocardiogram respectively.

RESULTS

Significant improvements were found in intergroup and intragroup comparison after 4 weeks of cardiac rehabilitation (p < 0.05). Scores of 6 MWT and LVEF significantly improved in the intervention group (p < 0.003) compared to the control group (p < 0.032). HQoL components that is, global and physical, MET values and average number of steps were significantly higher in the intervention group compared to the control group (p < 0.001).

CONCLUSION

SOCRP with power walking was more effective in improving HQoL, FEC, LVEF, METs and average numbers of steps than SOCRP alone although both interventions were significant after 4 weeks in patients underwent CA and completed cardiac rehabilitation program. Positive significant associations were found between the average number of steps taken with scores of METs and scores of global and physical domains of HQoL.

A history of smoking does not reduce long-term benefits of cardiac rehabilitation on cardiorespiratory fitness in men and women with cardiovascular disease

Smoking is an important risk factor for cardiovascular disease and all-cause mortality. Cardiac rehabilitation (CR) is effective for reducing the risk of recurrent cardiac events through improving cardiorespiratory fitness (CRF). Little is known about the influence of smoking on CRF throughout long-term CR. The purpose of this analysis was to compare CRF trajectories among individuals with positive and negative smoking history enrolled in long-term CR. Participants had a positive smoking history if they currently or formerly smoked (Smoke+, n = 55, mean age = 64.9 ± 9.0 years) and had a negative history if they never smoked (Smoke–, n = 34, mean age = 61.4 ± 9.0 years). CRF (peak oxygen uptake) was measured at baseline and annually thereafter for 6 years. The Smoke+ group had lower CRF compared with the Smoke– group over enrollment (β = −3.29 (SE = 1.40), 95% confidence interval (CI) −6.04 to −0.54, p = 0.02), but there was no interaction of smoking history and enrollment (β = 0.35 (SE = 0.21), 95% CI: −0.06 to 0.77, p = 0.10). Moreover, trajectories were not influenced by pack-years (β = 0.01 (SE = 0.01), 95% CI: −0.01 to 0.04, p = 0.23) or time smoke-free (β = −0.002 (SE = 0.01), 95% CI: −0.02 to 0.02, p = 0.80). Although the trajectories of CRF do not appear to be affected by smoking behaviour, individuals without a history of smoking maintained higher CRF throughout enrollment.

Novelty:

The benefits of long-term exercise-based cardiac rehabilitation on cardiorespiratory fitness are similar between those who have smoked and those who have never smoked. Neither the number of pack-years nor the length of time spent smoke-free influence cardiorespiratory fitness trajectories following long-term cardiac rehabilitation.

Effectiveness of Resistance Training with the Use of a Suspension System in Patients after Myocardial Infarction

The aim of the study was to assess the effects of resistance training with the use of a suspension system on exercise tolerance, evaluated through an exercise test, and the changes in selected echocardiographic parameters of patients after myocardial infarction. The study involved 44 males. The subjects were divided into two groups: Standard (20) and Suspension system (24). All the subjects had undergone an angioplasty with stent implantation. The standard and suspension system groups carried out a 24-day improvement program comprising 22 training units. Each session consisted of endurance, general stamina and resistance training. Instead of resistance training, the experimental group made multijoint exercises with a suspension system. Statistically significant changes in both groups were observed in the parameters of the echocardiographic exercise test, such as test duration (p = 0.000), distance covered (p = 0.000), MET (p = 0.000), VO2max (p = 0.000) and SBPrest (p = 0.013). Additionally, SBPmax in the suspension system group improved (p = 0.035). The echocardiographic test revealed significant improvement of Left Ventricular Ejection Fraction in both groups (SP group p = 0.001, standard group p = 0.005). The lipid profile test in the SP group revealed statistically significant improvement of TC (p = 0.003), HDL (p = 0.000) and LDL (p = 0.005). Training with the suspension system had a positive effect on the change of exercise tolerance level, left ventricular function and blood lipid profile.

Differential Impact of a Cardiac Rehabilitation Program on Functional Parameters in Elderly versus Non-Elderly Myocardial Infarction Survivors

BACKGROUND

Exercise-based cardiac rehabilitation (EBCR) plays a pivotal role in the management of acute myocardial infarction (AMI). Studies have shown that older individuals have a worse prognosis after an AMI, attesting to the importance of risk reduction strategies. We aimed at assessing the impact of age (patients dichotomized as ≥65 years old or <65 years old) on the functional benefits of an EBCR program among AMI survivors.

DESIGN

Observational, retrospective cohort study.

PARTICIPANTS

All patients admitted due to an AMI who completed a phase II EBCR program after discharge, between November 2012 and April 2017.

INTERVENTION

EBCR program.

MEASUREMENTS

Functional parameters were assessed by a symptom-limited cardiopulmonary exercise test.

RESULTS

A total of 379 patients were included (30% aged ≥65 years). After the EBCR program, peak oxygen uptake (pVO2) and exercise duration increased significantly. Patients aged ≥65 years presented with more comorbidities and a lower functional capacity. Those aged ≥65 years presented significantly smaller improvements in pVO2 (0.79 ± 2.61 vs. 1.60 ± 3.11 mL/kg/min, p = 0.016) and exercise duration [75 (59-120) vs. 120 s (60-180), p = 0.002]. This was maintained after adjusting for several potential confounders.

CONCLUSION

Older patients have a worse functional capacity than their younger counterparts. Still, a contemporary EBCR program was associated with significant functional improvements among those aged ≥65 years. The smaller improvements even after adjustments for potential confounders suggest that physiological differences may contribute to this finding. These results highlight the relevance of EBCR among this higher-risk subgroup.

Predictors of cardiorespiratory fitness improvement in phase II cardiac rehabilitation

BACKGROUND

Cardiac rehabilitation (CR) improves cardiorespiratory fitness (CRF) and has been shown to reduce cardiovascular events and death. However, data about predictors of fitness improvement during CR are limited and conflicting. The objective of this study was to determine predictors of improvement in metabolic equivalents of task (METs) based on formal exercise testing throughout phase II CR.

METHODS

We retrospectively reviewed 20 671 patients enrolled in phase II CR at our center from 2006 to 2016. Patients who completed 36 sessions and had entry and exit exercise stress tests were included for study. The short form-36 (SF-36) questionnaire was used to assess quality-of-life. Univariate and multivariate regression analyses were performed to determine independent predictors of METs improvement.

RESULTS

Of the full cohort, 827 patients completed 36 sessions and had entry/exit stress test data. The majority of patients (N = 647, 78.2%) had improvement in METs (mean Δ 2.0 ± 1.2 METs), including patients ≥65 and < 65 years old (77% vs 79%, P = 0.46 for difference). METs improvement was negatively associated with body mass index, diabetes, left ventricular dysfunction, and poor baseline fitness; and positively associated with SF-36 score (P < 0.05 for all). After multivariable adjustment, improvement was no longer affected by age, ejection fraction, or baseline fitness. Patients with poor fitness (≤5 METS) and adequate fitness (> 5 METS) both had improvement, with no statistical difference between the groups (P = 0.36).

CONCLUSIONS

In a large cohort of phase II CR patients, improvement in CRF was seen in the majority of patients across all ages, genders, and levels of baseline fitness.