Submaximal effort tolerance as a predictor of all-cause mortality in patients undergoing cardiac rehabilitation

Anxiety Predicts Worse Cardiorespiratory Fitness Outcomes in Cardiac Rehabilitation for Lower Socioeconomic Status Patients

PURPOSE

The purpose of this study was to show that patients in cardiac rehabilitation (CR) with lower socioeconomic status (SES) have worse clinical profiles and higher rates of psychiatric difficulties and they have lower cardiorespiratory fitness (CRF) improvements from CR than their counterparts with higher SES. Improvement in CRF during CR predicts better long-term health outcomes. Research suggests that higher anxiety impairs CRF in structured exercise regimes and is overrepresented among patients with lower SES. However, no study has determined whether this relationship holds true in CR.

METHODS

This study is a secondary analysis of a randomized controlled trial to improve CR attendance among patients with lower SES. Anxiety (ASEBA ASR; Achenbach System of Empirically Based Assessment, Adult Self Report) and CRF measures (metabolic equivalent tasks [METs peak ]) were collected prior to CR enrollment and 4 mo later. Regression was used to examine the association of anxiety with CRF at 4 mo while controlling for other demographic and clinical characteristics.

RESULTS

Eight-eight participants were included in the analyses, 31% of whom had clinically significant levels of anxiety ( T ≥ 63). Higher anxiety significantly predicted lower exit CRF when controlling for baseline CRF, age, sex, qualifying diagnosis, and number of CR sessions attended ( β =-.05, P = .04). Patients with clinically significant levels of anxiety could be expected to lose >0.65 METs peak in improvement.

CONCLUSIONS

The results from this study suggest that anxiety, which is overrepresented in populations with lower SES, is associated with less CRF improvement across the duration of CR. The effect size was clinically meaningful and calls for future research on addressing psychological factor in CR.

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.

Exercise Prescription and Progression Practices among US Cardiac Rehabilitation Clinics

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

Cancer and cardiovascular disease: The impact of cardiac rehabilitation and cardiorespiratory fitness on survival

BACKGROUND

Cancer survivors are at increased risk for cardiovascular disease (CVD)-related morbidity and mortality. Exercise-based cardiac rehabilitation (CR) programs improve CVD risk factors, including cardiorespiratory fitness (CRF). The purpose of this study was to investigate: (1) the association between CR completion and survival, and (2) whether CRF improvements translate to increased survival among patients with comorbid cancer and CVD.

METHODS

Patients with CVD and pre-existing cancer (any type) were referred to a 12-week exercise-based CR program between 01/1996 and 03/2016. Peak metabolic equivalents (METs) were assessed by graded exercise test pre-CR and at 12-weeks. Kaplan-Meier survival and multivariate cox regressions were performed to evaluate impact of CR completion and clinically-meaningful CRF improvements [ΔMETs≥1] on survival, adjusting for relevant covariates.

RESULTS

Among 442 patients with CVD and cancer referred to CR (67 ± 10 years; 22% women), 361 (82%) completed CR. 102 deaths were recorded during the 12-year observation period. Compared to patients who did not complete CR, patients with comorbid cancer who completed CR demonstrated a survival advantage (63% vs 80.1%, p < .001). CRF improved among completers during the 12-week program (mean change = 0.87 ± 0.93 METs, p < .001); 41% experienced a clinically-meaningful ΔMETs≥1. A survival advantage was not observed in completers who experienced a ΔMETs≥1 improvement (p = .254).

CONCLUSION

Completing a 12-week exercise-based CR program improved CRF and increased survival in patients with CVD and comorbid cancer. The results highlight the survival benefits of completing a CR program among CVD patients who experience added barriers imposed by cancer treatment and survival.

Impact of cardiorespiratory fitness on outcomes in cardiac rehabilitation

Cardiovascular rehabilitation (CR) significantly improves outcomes in patients with cardiovascular diseases (CVD), especially coronary heart disease and heart failure (HF). Although CR is often considered as an exercise training (ET) program for patients following CVD events, CR is more than just ET as it involves education, dietary and psychological counseling, as well as a multi-factorial risk factor modification. However, a major component of ET involves efforts to measure and improve levels of cardiorespiratory fitness (CRF). In this state-of-the-art review, we analyze the data, including from our John Ochsner Heart and Vascular Institute, evaluating CRF and its impact on psychological improvements and major outcomes with CR, especially long-term survival.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The utility of boxing for cardiac prehabilitation

A 56-year-old man with end-stage heart failure performed a 4-week, symptom-limited, progressive inpatient cardiac prehabilitation program while confined to the cardiovascular intensive care unit awaiting heart transplantation. Mobility was limited by an acute gout flare and multiple central venous access lines. He received a tailored prescription of intermittent boxing, supervised hallway ambulation, stair training, and golfing on a putting green on four consecutive weekdays and was encouraged to mobilize with nursing on the remaining days. The patient progressed and by the last week demonstrated increased activity tolerance. He had a successful transplant after 40 days in the intensive care unit and was discharged with stamina sufficient to participate in outpatient cardiac rehabilitation, demonstrating the value, safety, and feasibility of an individualized inpatient cardiac prehabilitation program for patients with advanced cardiac disease medically confined to the intensive care unit.

Exercise training with cycle ergometry in the intensive care unit after total artificial heart implantation

A 53-year-old male mountain biker received a total artificial heart and remained in the cardiovascular intensive care unit for 56 days. To reduce functional decline caused by inactivity, he performed a six-session cycle ergometer exercise program in his hospital room. Traditional cardiac responses for exercise prescription were not applicable; therefore, a symptom-limited, monitored progression scheme in conjunction with recommendations for the artificial heart was implemented to modify duration and intensity. Over the six sessions, the patient improved his distance pedaled by 320% and functional capacity by 1 metabolic equivalent. He was subsequently discharged from the hospital and later successfully transplanted without readmission.

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

Aerobic and resistance exercise training is a cornerstone of early outpatient cardiac rehabilitation (CR) and provides impressive benefits for patients. The components of the exercise prescription for patients with cardiovascular diseases are provided in guideline documents from several professional organizations and include frequency (how many sessions per week); intensity (how hard to exercise); time (duration of the exercise training session); type (modalities of exercise training); volume (the total amount or dose of exercise); and progression (the rate of increasing the dose of exercise). The least discussed, least appreciated, and most challenging component of the exercise prescription for CR health care professionals is the rate of progression of the dose of exercise. One reason for this observation is the heterogeneity of patients who participate in CR. All components of the exercise prescription should be developed specifically for each individual patient. This statement provides an overview of the principles of exercise prescription for patients in CR with special emphasis on the rate of progression. General recommendations for progression are given and patient case examples are provided to illustrate the principles of progression in exercise training.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Submaximal fitness and mortality risk reduction in coronary heart disease: a retrospective cohort study of community-based exercise rehabilitation

OBJECTIVES

To examine the association between submaximal cardiorespiratory fitness (sCRF) and all-cause mortality in a cardiac rehabilitation (CR) cohort.

DESIGN

Retrospective cohort study of participants entering CR between 26 May 1993 and 16 October 2006, followed up to 1 November 2013 (median 14 years, range 1.2-19.4 years).

SETTING

A community-based CR exercise programme in Leeds, West Yorkshire, UK.

PARTICIPANTS

A cohort of 534 men (76%) and 136 women with a clinical diagnosis of coronary heart disease (CHD), aged 22-82 years, attending CR were evaluated for the association between baseline sCRF and all-cause mortality. 416 participants with an exercise test following CR (median 14 weeks) were examined for changes in sCRF and all-cause mortality.

MAIN OUTCOME MEASURES

All-cause mortality and change in sCRF expressed in estimated metabolic equivalents (METs).

RESULTS

Baseline sCRF was a strong predictor of all-cause mortality; compared to the lowest sCRF group (<5 METs for women and <6 METs for men), mortality risk was 41% lower in those with moderate sCRF (HR 0.59; 95% CI 0.42 to 0.83) and 60% lower (HR 0.40; 95% CI 0.25 to 0.64) in those with higher sCRF levels (≥7 METs women and ≥8 METs for men). Although improvement in sCRF at 14 weeks was not associated with a significant mortality risk reduction (HR 0.91; 95% CI 0.79 to 1.06) for the whole cohort, in those with the lowest sCRF (and highest all-cause mortality) at baseline, each 1-MET improvement was associated with a 27% age-adjusted reduction in mortality risk (HR 0.73; 95% CI 0.57 to 0.94).

CONCLUSIONS

Higher baseline sCRF is associated with a reduced risk of all-cause mortality over 14 years in adults with CHD. Improving fitness through exercise-based CR is associated with significant risk reduction for the least fit.

Prognostic value of the post-training oxygen uptake efficiency slope in patients with coronary artery disease

BACKGROUND

Peak oxygen uptake is an independent predictor of mortality in patients with coronary artery disease (CAD). However, patients with CAD are not always capable of reaching peak effort, and therefore submaximal gas exchange variables such as the oxygen uptake efficiency slope (OUES) have been introduced. Baseline exercise capacity as expressed by OUES provides prognostic information and this parameter responds to training. Therefore, we aimed to assess the prognostic value of post-training OUES in patients with CAD.

METHODS

We included 960 patients with CAD (age 60.6 ± 9.5 years; 853 males) who completed a cardiac rehabilitation program between 2000 and 2011. The OUES was calculated before and after cardiac rehabilitation and information on mortality was obtained. The relationships of post-training OUES with all-cause and cardiovascular (CV) mortality was assessed by Cox proportional hazards regression analyses. Receiver operator characteristic curve analysis was performed in order to obtain the optimal cut-off value.

RESULTS

During 7.37 ± 3.20 years of follow-up (range: 0.45-13.75 years), 108 patients died, among whom 47 died due to CV reasons. The post-training OUES was related to all-cause (hazard ratio: 0.50, p < 0.001) and CV (hazard ratio: 0.40, p < 0.001) mortality. When significant covariates, including baseline OUES, were entered into the Cox regression analysis, post-training OUES remained related to all-cause and CV mortality (hazard ratio: 0.40, p < 0.01 and 0.26, p < 0.01, respectively). In addition, the change in OUES due to exercise training was positively related to mortality (hazard ratio: 0.49, p < 0.01).

CONCLUSION

Post-training OUES has stronger prognostic value compared to baseline OUES. The lack of improvement in exercise capacity expressed by OUES after an exercise training program relates to a worse prognosis and can help distinguish patients with favorable and unfavorable prognoses.

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

The purpose of this retrospective, observational study was to describe the relation between exercise workload during cardiac rehabilitation (CR), expressed as metabolic equivalents of task (METs), and prognosis among patients with coronary heart disease. We included patients with coronary heart disease who participated in CR between January 1998 and June 2007. METs were calculated from treadmill workload. Cox regression analysis was used to describe the relationship between METs and time to a composite outcome of all-cause mortality, nonfatal myocardial infarction, or heart failure hospitalization. Among 1,726 patients (36% women; median age 59 years [interquartile range, 52 to 66]), there were 467 events (27%) during a median follow-up of 5.8 years (interquartile range, 2.6 to 8.7). In analyses adjusted for age, sex, Charlson co-morbidity index, hypertension, diabetes, and CR referral diagnosis, METs were independently related to the composite outcome at CR start (Wald chi-square 43, hazard ratio 0.59 [95% confidence interval 0.51 to 0.70]) and CR end (Wald chi-square 47, hazard ratio 0.68 [95% confidence interval 0.61 to 0.76]). Patients exercising below 3.5 METs on exit from CR represent a high-risk group with 1- and 3-year event rates ≥7% and ≥18%, respectively. In conclusion, METs during CR is available at no additional cost and can be used to identify patients at increased risk for an event who may benefit from closer follow-up, extended length of stay in CR, and/or participation in other strategies aimed at maximizing adherence to secondary preventive behaviors and improving exercise capacity.

Early Rehabilitation Therapy Is Beneficial for Patients With Prolonged Mechanical Ventilation After Coronary Artery Bypass Surgery

We investigated the effects of early rehabilitation therapy on prolonged mechanically ventilated patients after coronary artery bypass surgery (CABG).A total of 106 patients who underwent CABG between June 2012 and May 2015 were enrolled and randomly assigned into an early rehabilitation group (53 cases) and a control group (53 cases). The rehabilitation therapy consisted of 6 steps including head up, transferring from supination to sitting, sitting on the edge of bed, sitting in a chair, transferring from sitting to standing, and walking along a bed. The patients received rehabilitation therapy in the intensive care unit (ICU) after CABG in the early rehabilitation group. The control group patients received rehabilitation therapy after leaving the ICU.The results showed that the early rehabilitation therapy could significantly decrease the duration of mechanical ventilation (early rehabilitation group: 8.1 ± 3.3 days; control group: 13.9 ± 4.1 days, P < 0.01), hospital stay (early rehabilitation group: 22.0 ± 3.8 days; control group: 29.1 ± 4.6 days, P < 0.01), and ICU stay (early rehabilitation group: 11.7 ± 3.2 days; control group: 18.3 ± 4.2 days, P < 0.01) for patients requiring more than 72 hours prolonged mechanical ventilation. The results of Kaplan-Meier analysis showed that the proportions of patients remaining on mechanical ventilation in the early rehabilitation group were larger than that in the control group after 7 days of rehabilitation therapy (logrank test: P < 0.01). The results provide evidence for supporting the application of early rehabilitation therapy in patients requiring prolonged mechanical ventilation after CABG.

Heart rate response to exercise and cardiorespiratory fitness of young women at high familial risk for hypertension: effects of interval vs continuous training

Exercise training is an effective intervention for treating and preventing hypertension, but its effects on heart rate (HR) response to exercise and cardiorespiratory fitness (CRF) of non-hypertensive offspring of hypertensive parents (FH+) has not been studied. We compared the effects of three times per week equal-volume high-intensity aerobic interval (AIT) and continuous moderate-intensity exercise (CME) on HR response to exercise and CRF of FH+. Forty-four young FH+ women (25.0 ± 4.4 years) randomized to control (CON; n = 12), AIT (80-90% of VO(2MAX); n = 16), or CME (50-60% of VO(2MAX); n = 16) performed a graded exercise test (GXT) before and after 16 weeks of follow-up to evaluate HR response to exercise and several parameters of CRF. Resting, maximal, and reserve HR did not change after the follow-up in all groups. HR recovery (difference between HR(MAX) and HR at 1 minute of GXT recovery phase) improved only after AIT (11.8 ± 4.9 vs. 20.6 ± 5.8 bpm, p < 0.01). Both exercise programmes were effective for improving CRF parameters, but AIT was more effective than CME for improving oxygen consumption at the respiratory compensation point (VO(2RCP); 22.1% vs. 8.8%, p = 0.008) and maximal effort (VO(2MAX); 15.8% vs. 8.0%, p = 0.036), as well as tolerance time (TT) to reach anaerobic threshold (TT(AT); 62.0 vs. 37.7, p = 0.048), TT(RCP) (49.3 vs. 32.9, p = 0.032), and TT(MAX) (38.9 vs. 29.2, p = 0.042). Exercise intensity was an important factor in improving HR recovery and CRF of FH+women. These findings may have important implications for designing exercise-training programmes for the prevention of an inherited hypertensive disorder.

Relationship between changes in heart rate recovery after cardiac rehabilitation on cardiovascular mortality in patients with myocardial infarction

BACKGROUND

Heart rate recovery (HRR) at predischarge exercise stress test predicts all-cause mortality in patients with myocardial infarction (MI), but the relationship between improvement in HRR with exercise training and clinical outcomes remains unclear.

OBJECTIVE

The purpose of this study was to evaluate the effect of change in HRR after exercise training on clinical outcomes in MI patients.

METHODS

The study included 386 consecutive patients with recent MI who were enrolled into our cardiac rehabilitation program. All patients underwent symptom-limited treadmill testing at baseline and after exercise training, and were prospectively followed-up in the outpatient clinic.

RESULTS

Treadmill testing revealed significant improvement in HRR after 8 weeks of exercise training (17.5 +/- 10.0 bpm to 19.0 +/- 12.3 bpm, P = .011). After follow-up of 79 +/- 41 months, 40 (10.4%) patients died of cardiac events. Multivariate Cox regression analysis revealed that diabetes (hazard ratio [HR] 2.28, 95% confidence interval [CI] 1.01-5.19, P = .049), statin use (HR 0.36, 95% CI 0.16-0.80, P = .012), baseline resting heart rate > or =65 bpm (HR 5.37, 95% CI 1.33-21.61, P = .018), post-training HRR <12 bpm (HR 2.49, 95% CI 1.10-5.63, P = .028), left ventricular ejection fraction < or =30% (HR 4.70, 95% CI 1.34-16.46, P = .016), and exercise capacity < or =4 metabolic equivalents (HR 3.63, 95% CI 1.17-11.28, P = .026) were independent predictors of cardiac death. Patients who failed to improve HRR from <12 bpm to > or =12 bpm after exercise training had significantly higher mortality (HR 6.2, 95% CI 1.3-29.2, P = .022).

CONCLUSION

Exercise training improved HRR in patients with recent MI, and patients with HRR increased to > or =12 bpm had better cardiac survival.

Prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation

BACKGROUND

The prognostic value of cycle exercise testing prior to and after outpatient cardiac rehabilitation (OCR) is not well established.

METHODS

2146 consecutive patients undergoing symptom-limited cycle exercise testing at OCR entry, of whom 1853 (86%) also had a test at end of OCR, were followed for a median of 33 months.

RESULTS

All-cause and cardiovascular annual mortality rates were 1.2% and 0.8%, respectively. At OCR entry, older age, diabetes, lower left ventricular ejection fraction (LVEF), calcium channel blocker use, and lower workload [hazard ratio (HR) 2.38 if < or = 105 W; p<0.001] were independent predictors of death. Diabetes, diuretic use, and lower workload [HR 3.53 if < or = 105 W; p=0.001] were independently associated with cardiovascular death. At end of OCR, older age, lower LVEF, lower workload (HR 2.34 if <140 W; p=0.009), and lower increase in peak heart rate from entry to end of OCR (HR 2.46 if <4 bpm; p=0.002) were independently associated with all-cause mortality. Older age, lower LVEF, lower increase in systolic blood pressure (HR 2.97 if <54 mm Hg; p=0.02), and lower increase in peak heart from entry to end of OCR (HR 2.72 if <4 bpm; p=0.013) were independently associated with cardiovascular mortality. Failure to undergo a test at end of OCR was an additional independent predictor of all-cause (HR 2.51; p<0.001) and cardiovascular mortality (HR 2.56; p=0.003).

CONCLUSION

Symptom-limited cycle exercise testing prior to and after OCR provides important prognostic information.