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 (METpeak) were determined pre- and post-CR during which total duration (ET time) and intensity [percent of heart rate peak (%HRpeak)] of supervised ET were also obtained. Training responsiveness was quantified on the basis of changes in METpeak 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 METpeak was progressively lower with greater training responsiveness (F(4,2305) = 44.2, P < 0.01, η2p = 0.71). Likewise, average training duration (F(4,2305) = 10.7 P < 0.01, η2p = 0.02) and %HRpeak (F(4,2305) = 25.1 P < 0.01, η2p = 0.042) quantified during onsite ET sessions were progressively greater with greater training responsiveness. The multivariable linear regression model confirmed that baseline METpeak, training duration and intensity during ET, BMI, and age (P < 0.001) were significant predictors of METpeak post-CR. CONCLUSIONS: Along with baseline METpeak, delta BMI, and age, the dose of ET (i.e., training duration and intensity) predicts METpeak 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.

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.

Cardiorespiratory fitness estimations and their ability to predict all-cause mortality in patients with cardiovascular disease.

Background: In cardiac rehabilitation programs, cardiorespiratory fitness is commonly estimated (eCRF) from the maximum workload achieved on a graded exercise test. This study compared four well-established eCRF equations in their ability to predict mortality in patients with cardiovascular disease (CVD). Methods: A total of 7269 individuals with CVD were studied (81% male; age 59.4 ± 10.3yr). eCRF was calculated using equations from the American College of Sports Medicine, Bruce et al., the Fitness Registry and the Importance of Exercise International Database, and McConnell and Clark. The eCRF from each equation was compared with a RMANOVA. Cox proportional hazard models assessed the relationship between the eCRF equations and mortality risk. The predictive ability of the models was compared using the concordance index. Results: There were 284 deaths (85% male) over a follow-up period of 5.8 ± 2.8yr. Although differences in eCRF were observed between each equation (P < 0.05), the eCRF from each of the four equations was predictive of mortality (P < 0.05). The concordance index values for each of the models were the same (0.77) indicating similar predictive performance. Conclusions: The four well-established eCRF equations did not differ in their ability to predict mortality in patients with CVD, indicating any could be used for this purpose. However, the differences in eCRF from each of the equations suggest potential differences in their ability to guide clinical care and should be the focus of future research.

An observational study examining utilization of prehabilitation and its association with postoperative cardiac rehabilitation participation and risk factors following coronary artery bypass grafting.

BACKGROUND: Growing evidence supports the use of prehabilitation before coronary artery bypass grafting (CABG) to improve surgical outcomes, but its feasibility and impact on risk factor management in real-world clinical settings remain unknown. This observational study examined prehabilitation utilization and its association with postoperative cardiac rehabilitation (CR) participation and cardiovascular risk profile. METHODS: As standard care in a large Canadian city, eligible patients were referred to prehabilitation upon entering the elective CABG waitlist then were re-referred to CR following surgery. Prehabilitation consisted of medically supervised exercise training and multidisciplinary support with health behavior change until the scheduled surgery. An assessment of cardiorespiratory fitness, blood pressure, body habitus, psychological distress, lipids, glycated hemoglobin, and smoking status was completed during a prehabilitation intake visit then was repeated after surgery prior to starting CR. RESULTS: Among 97 prehabilitation referrals over a 20-month period, only 49% attended an intake visit. Most patients who enrolled (n = 39) also completed (n = 37) prehabilitation. Completion of prehabilitation was significantly associated with higher CR referral (OR = 6.92, 95% CI 1.50-32.00), enrollment (OR = 14.08, 95% CI 5.09-38.94) and attendance [t(62) = 4.48, p < .001], and with improvements in cardiorespiratory fitness, body mass index, and symptoms of depression and anxiety (p < .004). CONCLUSIONS: Prehabilitation may improve CR participation and risk factors among individuals undergoing elective CABG, but more work is needed to disseminate this service to eligible patients.

Prediction of Mortality in Coronary Artery Disease: Role of Machine Learning and Maximal Exercise Capacity.

OBJECTIVE: To develop a prediction model for survival of patients with coronary artery disease (CAD) using health conditions beyond cardiovascular risk factors, including maximal exercise capacity, through the application of machine learning (ML) techniques. METHODS: Analysis of data from a retrospective cohort linking clinical, administrative, and vital status databases from 1995 to 2016 was performed. Inclusion criteria were age 18 years or older, diagnosis of CAD, referral to a cardiac rehabilitation program, and available baseline exercise test results. Primary outcome was death from any cause. Feature selection was performed using supervised and unsupervised ML techniques. The final prognostic model used the survival tree (ST) algorithm. RESULTS: From the cohort of 13,362 patients (60±11 years; 2400 [18%] women), 1577 died during a median follow-up of 8 years (interquartile range, 4 to 13 years), with an estimated survival of 67% up to 21 years. Feature selection revealed age and peak metabolic equivalents (METs) as the features with the greatest importance for mortality prediction. Using these 2 features, the ST generated a long-term prediction with a C-index of 0.729 by splitting patients in 8 clusters with different survival probabilities (P<.001). The ST root node was split by peak METs of 6.15 or less or more than 6.15, and each patient's subgroup was further split by age or other peak METs cut points. CONCLUSION: Applying ML techniques, age and maximal exercise capacity accurately predict mortality in patients with CAD and outperform variables commonly used for decision-making in clinical practice. A novel and simple prognostic model was established, and maximal exercise capacity was further suggested to be one of the most powerful predictors of mortality in CAD.

The impact of patient education on knowledge, attitudes, and cardiac rehabilitation attendance among patients with coronary artery disease.

OBJECTIVE: Patient education (PE) delivered during exercise-based cardiac rehabilitation (CR) aims to promote health behaviour change, including attendance at CR exercise sessions, by imparting knowledge about coronary artery disease (CAD) and improving CR-related attitudes. This study evaluated the impact of PE on aspects of patient motivation (i.e., CAD-related knowledge, attitudes towards CR) and exercise session attendance. METHODS: Adults with CAD referred to a 12-week CR program were recruited. CAD knowledge, perceived necessity/suitability of CR, exercise concerns, and barriers to CR were assessed pre/post-PE, and at 12-week follow-up. CR exercise attendance was obtained by chart review. RESULTS: Among 90 patients (60 ± 10 years; 88% men), CAD knowledge and perceived necessity of CR improved pre- to post-PE; gains persisted at 12-weeks. Stronger pre-CR intentions to attend exercise sessions predicted greater attendance. Greater knowledge gains did not predict improvements in CR attitudes or exercise attendance. CONCLUSION: Whereas PE may be useful for improving knowledge and attitudes regarding CAD self-management, more formative research is needed to determine whether PE can promote CR attendance. PRACTICE IMPLICATIONS: Cardiac PE programs may be more successful in promoting exercise attendance if they target patients' behavioural intentions to attend and attitudes toward CR, rather than focussing exclusively on imparting knowledge.

Identification of Patients With COPD in a Cardiac Rehabilitation Setting: THE COnCuR STUDY.

PURPOSE: To examine the feasibility of screening for chronic obstructive pulmonary disease (COPD) in an outpatient cardiac rehabilitation (CR) setting and to evaluate the detection rate of COPD using a targeted screening protocol. METHODS: A total of 95 patients (62.5 ± 10.0 yr; men, n = 77), >40-yr old with a history of smoking were included in the study sample. Each participant answered the 5-item Canadian Lung Health Test (CLHT) questionnaire assessing symptoms such as coughing, phlegm, wheezing, shortness of breath, and frequent colds. Endorsing ≥1 item was indicative of potential COPD and warranted pulmonary function testing (PFT) and/or spirometry to diagnose or rule out COPD. RESULTS: The CLHT questionnaire identified 44 patients at risk for COPD, with an average of 1.9 ± 1.2 items endorsed. Of the patients who underwent PFT, 6 new cases of mild COPD were diagnosed, resulting in a true positive rate with CLHT screening of 19% and a false-positive rate of 81%. CONCLUSIONS: Implementing the CLHT to patients referred to CR correctly identified COPD in <20% of cases. Using the CLHT to screen for COPD prior to starting CR may not be optimal, due to disparities between true- and false-positive rates.

Factors Associated With Attendance at a 1-yr Post-Cardiac Rehabilitation Risk Factor Check.

PURPOSE: Patients with coronary artery disease (CAD) often fail to maintain secondary prevention gains after completing cardiac rehabilitation (CR). Follow-up appointments aimed at assessing cardiac status and encouraging maintenance of health behaviors after CR completion are generally offered but not well-attended. This study explored patient characteristics and barriers associated with nonattendance at a 1-yr follow-up visit following CR completion. METHODS: Forty-five patients with CAD who completed a 12-wk outpatient CR program but did not attend the 1-yr follow-up appointment were included. Participants responded to a survey consisting of open-ended questions about follow-up attendance, a modified version of the Cardiac Rehabilitation Barriers Scale, and self-report items regarding current health practices and perceived strength of recommendation to attend. Thematic analysis was used to derive categories from open-ended questionnaire responses. Linear regression was used to assess characteristics associated with appointment attendance barriers. RESULTS: Barrier themes were as follows: (1) lack of awareness; (2) perception of appointment as unnecessary; (3) practical or scheduling issues; (4) comorbid health issues; and (5) anticipated an unpleasant experience at the appointment. Greater self-reported barriers (mean ± SD = 1.97/5.00 ± 0.57) were significantly associated with lower perceived strength of recommendation to attend the follow-up appointment (2.82/5.00 ± 1.45), P = .005. CONCLUSIONS: Providing a stronger recommendation to attend, enhancing patient awareness, highlighting potential benefits, and supporting self-efficacy might increase 1-yr follow-up appointment attendance and, in turn, support long-term adherence to cardiovascular risk reduction behaviors.

Cardiometabolic responses to cardiac rehabilitation in people with and without diabetes.

BACKGROUND: Type 2 diabetes and cardiometabolic comorbidities manifesting as the metabolic syndrome (MetS) are highly prevalent in coronary heart disease (CHD) patients attending cardiac rehabilitation (CR). The study aimed to determine the prevalence of cardiometabolic derangements and MetS, and compare post-CR clinical responses in a large cohort of CHD patients with and without diabetes. METHODS: Analyses were conducted on 3953 CHD patients [age: 61.1 ±â€¯10.5 years; 741 (18.7%) with diabetes] that completed a representative 12-week CR program. A propensity model was used to match patients with diabetes (n = 731) to those without diabetes (n = 731) on baseline and clinical characteristics. RESULTS: Diabetic patients experienced smaller improvements in metabolic parameters after completing CR, including abdominal obesity, and lipid profiles (all P ≤ .002), compared to non-diabetic patients. For both groups, there were similar improvement rates in peak metabolic equivalents ([METs]; P < .001); however, peak METs remained lower at 12-weeks in patients with diabetes than without diabetes. At baseline, the combined prevalence of insulin resistance (IR) and diabetes was 57.3%, whereas IR was present in 48.2% of non-diabetic patients, of which rates were reduced to 48.2% and 32.8% after CR, respectively. Accordingly, MetS prevalence decreased from 25.5% to 22.3% in diabetic versus 20.0% to 13.4% in non-diabetic patients (all P ≤ .004). CONCLUSIONS: Completing CR appears to provide comprehensive risk reduction in cardio-metabolic parameters associated with diabetes and MetS; however, CHD patients with diabetes may require additional and more aggressive attention towards all MetS criteria over the course of CR in order to prevent future cardiovascular events.

Automated Referral to Cardiac Rehabilitation After Coronary Artery Bypass Grafting Is Associated With Modest Improvement in Program Completion.

BACKGROUND: Cardiac rehabilitation (CR) is a guideline-indicated modality for reducing residual cardiovascular risk among patients undergoing coronary artery bypass grafting (CABG) surgery. However, many referred patients do not initiate or complete a CR program; even more patients are never even referred. METHODS: All post-CABG patients in Calgary, Alberta, Canada, from January 1, 1996, to March 31, 2016, were included. Data were obtained from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease and TotalCardiology Rehabilitation databases. Automated referral to CR at discharge after CABG was instituted on July 1, 2007. We used interrupted time series analysis to evaluate the impact of automated referral on CR referral and completion rates and studied the association of these CR process markers with mortality. RESULTS: A total of 8,118 patients underwent CABG surgery during the study period: 5,103 before automation and 3,015 after automation. Automation increased referral rates from 39.5% to 75.0% (P < 0.001). Automated referral was associated with a 7.2% increase in CR completion in the overall population (33.3% vs 26.1%; P < 0.001). In adjusted models, CR referral alone was not associated with reduced mortality (hazard ratio [HR] 0.84, 95% CI 0.64-1.11), but CR completion was (HR 0.43, 95% CI 0.31-0.61). CONCLUSION: Automated referral in post-CABG patients resulted in modest improvement in CR program completion. Therefore, even when CR referral is automated to include all eligible patients, additional strategies to support CR program enrollment and completion remain necessary to achieve the desired health benefits.

Integrating Science, Practice, and Mentorship in Cardiac Rehabilitation: THE INAUGURAL TOTALCARDIOLOGY® RESEARCH NETWORK RETREAT.

The evidence base supporting cardiac rehabilitation is substantial and overwhelmingly supports its utilization for all qualified patients. However, important lines of inquiry remain and require attention. This commentary provides a model for cardiac rehabilitation centers that provide patient care to meaningfully contribute to our scientific understanding of this lifestyle intervention.

Cardiac rehabilitation in people with peripheral arterial disease: A higher risk population that benefits from completion.

BACKGROUND: Peripheral arterial disease (PAD) is common in people referred for cardiac rehabilitation (CR). However, the associations between PAD diagnosis and CR attendance and mortality remain to be defined. METHODS: All patients referred to a 12-week exercise-based CR program were included. Associations between PAD diagnosis and starting CR as well as between PAD diagnosis and completing CR were measured using multivariable logistic regression. Associations between CR completion and mortality were measured using adjusted Cox proportional hazards models, and a propensity-based matching sensitivity analysis was performed. RESULTS: 23,215 patients (mean age 61.3 years; 21.6% female) were referred to CR; 1366 (5.9%) had PAD. Those with PAD were less likely to start CR (57.0% vs 68.2%, adjusted OR 0.81, 95%CI 0.72, 0.91) and complete CR if they started (70.6% vs 76.7%, adjusted OR 0.80, 95%CI 0.68, 0.94). Patients with PAD completing CR had lower exercise capacity at baseline (6.6 vs. 7.6 METs, p < 0.0001) and completion (7.5 vs 8.6 METs, p < 0.0001). There were 3510 deaths over follow-up; 10-year survival was lower in those with PAD (66.9 vs 84.5%; p < 0.0001). CR completion was associated with lower mortality for all (adjusted HR 0.62 (95%CI 0.57, 0.67)), and the magnitude of the association was independent of PAD status. CONCLUSIONS: Patients with PAD referred to CR had a higher mortality than those without, and were less likely to start and complete CR. Completion of CR was associated with improved fitness and survival for PAD patients. These data support broader use of CR by those with PAD.

Factors Associated With Cardiorespiratory Fitness at Completion of Cardiac Rehabilitation: Identification of Specific Patient Features Requiring Attention.

BACKGROUND: We aimed to determine and compare predictors of postcardiac rehabilitation (CR) cardiorespiratory fitness (CRF), improvements in a large cohort of subjects with varying baseline CRF levels completing CR for ischemic heart disease and to refine prediction models further by baseline CRF. METHODS: The Alberta Provincial Project for Outcomes Assessment in Coronary Heart disease (APPROACH) and TotalCardiology (TotalCardiology, Inc, Calgary, Alberta, Canada) databases were used retrospectively to obtain information on 10,732 (1955 [18.2%] female; mean age 60.4, standard deviation [SD] 10.5 years) subjects who completed the 12-week comprehensive CR program between 1996 and 2016. Peak metabolic equivalents (METs) were determined at program start and completion and identified patients at baseline with low fitness (L-Fit) (< 5 METs), moderate fitness (M-Fit, 5-8 METs), or high fitness (H-Fit, > 8 METs). Multivariable linear regression models were developed to predict METs at completion of the program. RESULTS: Across all fitness groups, mean baseline METs was the strongest predictor of CRF at completion of CR. Other factors-including sex, age, current smoking status, obesity, and diabetes-were highly predictive of post-CR CRF (all P < 0.05). Compared with H-fit patients, coronary artery bypass graft and chronic obstructive pulmonary disease in L-Fit patients, and cerebrovascular disease in M-Fit patients had an additional negative effect on the overall model variance in post-CR CRF. CONCLUSION: Expected CRF at the end of CR is highly predictable, with several key patient factors being clear determinants of CRF. Although most identified patient factors are not modifiable, our analysis highlights populations that may require extra attention over the course of CR to attain maximal benefit.

Optimizing Value From Cardiac Rehabilitation: A Cost-Utility Analysis Comparing Age, Sex, and Clinical Subgroups.

OBJECTIVE: To assess the cost utility of a center-based outpatient cardiac rehabilitation program compared with no program within patient subgroups on the basis of age, sex, and clinical presentation (acute coronary syndrome [ACS] or non-ACS). METHODS: We performed a cost-utility analysis from a health system payer perspective to compare cardiac rehabilitation with no cardiac rehabilitation for patients who had a cardiac catheterization. The Markov model was stratified by clinical presentation, age, and sex. Clinical, quality-of-life, and cost data were provided by the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease and TotalCardiology. RESULTS: The incremental cost per quality-adjusted life-year (QALY) gained for cardiac rehabilitation varies by subgroup, from $18,101 per QALY gained to $104,518 per QALY gained. There is uncertainty in the estimates due to uncertainty in the clinical effectiveness of cardiac rehabilitation. Overall, the probabilistic sensitivity analysis found that 75% of the time participation in cardiac rehabilitation is more expensive but more effective than not participating in cardiac rehabilitation. CONCLUSION: The cost-effectiveness of cardiac rehabilitation varies depending on patient characteristics. The current analysis indicates that cardiac rehabilitation is most cost effective for those with an ACS and those who are at higher risk for subsequent cardiac events. The findings of the current study provide insight into who may benefit most from cardiac rehabilitation, with important implications for patient referral patterns.

Cardiac rehabilitation completion is associated with reduced mortality in patients with diabetes and coronary artery disease.

AIMS: Cardiac rehabilitation (CR) reduces the risks of mortality and hospitalisation in patients with coronary artery disease and without diabetes. It is unknown whether patients with diabetes obtain the same benefits from CR. METHODS: We retrospectively examined patients referred to a 12 week CR programme between 1996 and 2010. Associations between CR completion vs non-completion and death, hospitalisation rate and cardiac hospitalisation rate were assessed by survival analysis. RESULTS: Over the study period, 13,158 participants were referred to CR (mean ± SD, age 59.9 ± 11.1 years, 28.9% female, 2,956 [22.5%] with diabetes). Patients with diabetes were less likely to complete CR than those without diabetes (41% vs 56%, p < .0001). Over a median follow-up of 6.6 years, there were 379 deaths in patients with diabetes vs 941 deaths among those without diabetes (12.8% vs 8.9%). Of the non-completers, patients with diabetes had a higher mortality rate compared with those without diabetes (17.7% vs 11.3%). In patients who completed CR, mortality was lower: 11.1% in patients with diabetes vs 7.0% in those without diabetes. In patients with diabetes, CR completion was associated with reduced mortality (HR 0.46 [95% CI 0.37, 0.56]), reduced hospitalisation (HR 0.86 [95% CI 0.76, 0.96]) and reduced cardiac hospitalisation (HR 0.67 [95% CI 0.54, 0.84]). The protective associations were similar to those of patients without diabetes. In multivariable adjusted analyses, all of these associations remained significant. CONCLUSIONS: Patients with diabetes were less likely to complete CR than those without diabetes. However, patients with diabetes who completed CR derived similar apparent reductions in mortality and hospitalisation to patients without diabetes.

Exercise therapy for heart failure patients in Canada.

Contemporary pharmacologic therapies have greatly improved outcomes in patients with heart failure (HF). Exercise therapy also has become increasingly recognized and utilized over the last decade. Patients with HF undergo significant central and peripheral deconditioning. Aerobic and resistance training in this patient population may improve quality of life, muscular strength, aerobic capacity, and potentially longevity. Those HF patients who are able to remain adherent to exercise training programs may improve their self-monitoring skills with respect to progressive volume overload, as well as their capacity for independent living, thereby reducing the likelihood of rehospitalization.

Cardiac rehabilitation referral, attendance and mortality in women.

BACKGROUND: Cardiac rehabilitation (CR) reduces mortality in women and men with coronary artery disease (CAD). The objective of this study was to examine sex differences in long-term mortality, based on CR referral rates and attendance patterns in a large CAD population. DESIGN: This is a retrospective cohort study. METHODS: The Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) and Cardiac Wellness Institute of Calgary (CWIC) databases were used to obtain information on all patients. Rates of referral to and attendance at CR were compared by sex. Logistic regression models were constructed to assess whether sex predicted CR referral or completion. The association between referral, completion, and survival was assessed by sex using Cox proportional hazard models. RESULTS: 25,958 subjects (6374-24.6%-were women) with at least one vessel CAD were included. Females experienced reduced rates of CR referral (31.1% vs 42.2%, p < 0.0001) and completion (50.1 vs 60.4%, p < 0.0001). Adjusting for demographic and clinical characteristics, relative to men, CR referral was significantly lower in women (adjusted odds ratio (OR) 0.74, 95% CI 0.69, 0.79) as was CR completion (adjusted OR 0.73, 95% CI 0.66, 0.81). Women completing CR experienced the greatest reduction in mortality (HR 0.36, 95% CI 0.28, 0.45) with a relative benefit greater than men (HR 0.51, 95% CI 0.46, 0.56). CONCLUSION: This is the first large cohort study to demonstrate that referral to and attendance at CR is associated with a significant mortality reduction in women, comparatively better than that in men.

Patients with diabetes in cardiac rehabilitation: attendance and exercise capacity.

PURPOSE: Diabetes increases mortality after myocardial infarction, but participation in cardiac rehabilitation (CR) reduces this risk. Our objectives were to examine whether attendance at CR and changes in cardiorespiratory fitness differed according to diabetic status and sex. METHODS: Retrospective cohort study of patients referred for CR in Calgary between 1996 and 2010. Cardiorespiratory fitness in metabolic equivalents (METs) was estimated by maximal exercise testing at baseline, at the end of the 12-wk CR program, and 1-yr after CR. RESULTS: Among 7036 nondiabetic and 1546 diabetic patients who started, 84.9% of nondiabetic versus 79.5% of diabetic patients completed CR (P < 0.0001). The difference between diabetic and nondiabetic patients was greater in women (81.7% vs 72.1%, P < 0.0001) than that in men (86.0% vs 82.5%, P = 0.004). Patients without diabetes were more likely to return for the 1-yr assessment (53.7% vs 42.7%, P < 0.0001), and nondiabetic women were more likely than diabetic women to attend the 1-yr follow-up (44.3% vs 31.7%, P < 0.0001). Change in cardiorespiratory fitness from baseline to 12 wk was +1.0 METs in nondiabetic men, +0.9 METS in diabetic men, +0.9 METs in nondiabetic women, and +0.7 METs in diabetic women (within-group change; P = 0.0009). Changes in cardiorespiratory fitness at 1 yr compared with baseline were +0.9, +0.6, +0.9, and +0.5 METS, respectively (within-group change, P = 0.0001). CONCLUSIONS: Patients with diabetes, especially females, were less likely than patients without diabetes to complete CR and attend follow-up. Among patients who attended 1-yr follow-up, changes in cardiorespiratory fitness were not as well maintained in diabetic patients as in nondiabetic patients. Identifying barriers and targeting CR adherence interventions to patients with diabetes may help improve outcomes.

Cardiovascular fitness and mortality after contemporary cardiac rehabilitation.

OBJECTIVE: To assess the association between cardiorespiratory fitness (CRF) and outcomes in a cardiac rehabilitation (CR) cohort. PATIENTS AND METHODS: We conducted a retrospective study of 5641 patients (4282 men [76%] and 1359 women [24%]; mean ± SD age, 60.0±10.3 years) with coronary artery disease who participated in CR between July 1, 1996, and February 28, 2009. Based on peak metabolic equivalents (METs), patients were classified as low fitness (LFit) (<5 METs), moderate fitness (5-8 METs), or high fitness (>8 METs). RESULTS: Baseline fitness predicted long-term mortality: relative to the LFit group, patients with moderate fitness had an adjusted hazard ratio of 0.54 (95% CI, 0.42-0.69), and those with high fitness a hazard ratio of 0.32 (95% CI, 0.24-0.44). Improvement in CRF at 12 weeks was associated with decreased overall mortality, with a 13% point reduction with each MET increase (P<.001) and a 30% point reduction in those who started with LFit. At 1 year, each MET increase in CRF was associated with a 25% point reduction in overall mortality in the whole group (P<.001). CONCLUSION: In this study of contemporary CR patients, higher baseline fitness predicted lower mortality. The novel finding was that improvement in fitness during a CR program and improvements that persisted at 1 year were also associated with decreased mortality, most strongly in patients who start with LFit.

An investigation of the benefits of stress management within a cardiac rehabilitation population.

PURPOSE: Research describing whether stress management can improve clinical outcomes for patients in cardiac rehabilitation (CR) has yielded equivocal findings. METHODS: The present investigation retrospectively examined the incremental impact of exercise and stress management (n = 188), relative to exercise only (n = 1389), on psychosocial and physical health outcomes following a 12-week CR program. RESULTS: Participation in stress management and exercise was associated with greater reductions in waist circumference and systolic blood pressure, relative to exercise alone, for patients with baseline clinical elevations on these measures. The stress management group had more depressive symptoms (as measured by the Hospital Anxiety and Depression Scale; t[1] = 3.81, P < .001) and lower physical quality of life (as measured by the 12-Item Short Form Health Survey Physical Component; t[1] = 3.00, P = .003) than the exercise-only group at baseline, but there were no differences between the groups at 12 weeks in terms of depressive symptoms (t[1] = 1.74, P = .082) or physical quality of life (t[1] = 1.56, P = .120). CONCLUSION: These findings suggest that stress management may offer additional benefits in selected patients over and above exercise in CR.