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The improving ATTENDance (iATTEND) to cardiac rehabilitation (CR) trial tested the hypotheses that hybrid CR (HYCR) (combination of virtual and in-facility CR sessions) would result in greater attendance compared with traditional, facility-based only CR (FBCR) and yield equivalent improvements in exercise capacity and health status. Patients were randomized to HYCR (n = 142) or FBCR (n = 140), stratified by gender and race. Attendance was assessed as number of CR sessions completed within 6 months (primary end point) and the percentage of patients completing 36 CR sessions. Other end points (tested for equivalency) included exercise capacity and self-reported health status. HYCR patients completed 1 to 12 sessions in-facility, with the balance completed virtually using synchronized, 2-way audiovisual technology. Neither total number of CR sessions completed within 6 months (29 ± 12 vs 28 ± 12 visits, adjusted p = 0.94) nor percentage of patients completing 36 sessions (59 ± 4% vs 51 ± 4%, adjusted p = 0.32) were significantly different between HYCR and FBCR, respectively. The between-group changes for exercise capacity (peak oxygen uptake, 6-minute walk distance) and health status were equivalent. Regarding safety, no sessions required physician involvement, there was 1 major adverse event after a virtual session, and no falls required medical attention. In conclusion, although we rejected our primary hypothesis that attendance would be greater with HYCR versus FBCR, we showed that FBCR and HYCR resulted in similar patient attendance patterns and equivalent improvements in exercise capacity and health status. HYCR which incorporates virtually supervised exercise should be considered an acceptable alternative to FBCR. NCT Identifier: 03646760; The Improving ATTENDance to Cardiac Rehabilitation Trial - Full-Text View - ClinicalTrials. gov; https://classic.clinicaltrials.gov/ct2/show/NCT03646760., Competing Interests: Declaration of competing interest Dr. Lanfear is a consultant for Abbott Laboratories, Astra Zeneca, Cytokinetics, Illumina (Lilly), Janssen, and Duke Clinical Research Institute (Novartis) and has participated in clinical research from Amgen, Akros, AstraZeneca, Bayer, Cytokinetics, Illumina, Pfizer (New York, New York, United States), and Janssen. The remaining authors have no competing interests to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Many cardiology associations endorse the role of the cardiopulmonary exercise test (CPET) to define the severity of impairment of functional capacity in individuals with heart failure with reduced ejection fraction (HFrEF) and when evaluating the need for advanced therapies for these patients. The focus of the CPET within the cardiology community has been on peak volume of oxygen uptake (VO 2 ). However, several CPET variables are associated with outcomes in individuals with and without chronic disease and can inform clinical decisions in individuals with HFrEF. In this manuscript, we will review the normal cardiopulmonary response to a graded exercise test and review current guideline recommendations relative to CPET in patients with HFrEF., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

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., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: To investigate the relationship between maximal exercise capacity measured before severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and hospitalization due to coronavirus disease 2019 (COVID-19)., Methods: We identified patients (≥18 years) who completed a clinically indicated exercise stress test between January 1, 2016, and February 29, 2020, and had a test for SARS-CoV-2 (ie, real-time reverse transcriptase polymerase chain reaction test) between February 29, 2020, and May 30, 2020. Maximal exercise capacity was quantified in metabolic equivalents of task (METs). Logistic regression was used to evaluate the likelihood that hospitalization secondary to COVID-19 is related to peak METs, with adjustment for 13 covariates previously identified as associated with higher risk for severe illness from COVID-19., Results: We identified 246 patients (age, 59±12 years; 42% male; 75% black race) who had an exercise test and tested positive for SARS-CoV-2. Among these, 89 (36%) were hospitalized. Peak METs were significantly lower (P<.001) among patients who were hospitalized (6.7±2.8) compared with those not hospitalized (8.0±2.4). Peak METs were inversely associated with the likelihood of hospitalization in unadjusted (odds ratio, 0.83; 95% CI, 0.74-0.92) and adjusted models (odds ratio, 0.87; 95% CI, 0.76-0.99)., Conclusion: Maximal exercise capacity is independently and inversely associated with the likelihood of hospitalization due to COVID-19. These data further support the important relationship between cardiorespiratory fitness and health outcomes. Future studies are needed to determine whether improving maximal exercise capacity is associated with lower risk of complications due to viral infections, such as COVID-19., (Copyright © 2020 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Objectives: To assess the influence of exercise capacity and body mass index (BMI) on 10-year mortality in patients with heart failure (HF) and to synthesize these results with those of previous studies., Patients and Methods: This large biracial sample included 774 men and women (mean age, 60±13 years; 372 [48%] black) with a baseline diagnosis of HF from the Henry Ford Exercise Testing (FIT) Project. All patients completed a symptom-limited maximal treadmill stress test from January 1, 1991, through May 31, 2009. Patients were grouped by World Health Organization BMI categories for Kaplan-Meier survival analyses and stratified by exercise capacity (<4 and ≥4 metabolic equivalents [METs] of task). Associations of BMI and exercise capacity with all-cause mortality were assessed using multivariable-adjusted Cox proportional hazards models., Results: During a mean follow-up of 10.1±4.6 years, 380 patients (49%) died. Kaplan-Meier survival plots revealed a significant positive association between BMI category and survival for exercise capacity less than 4 METs (log-rank, P=.05), but not greater than or equal to 4 METs (P=.76). In the multivariable-adjusted models, exercise capacity (per 1 MET) was inversely associated, but BMI was not associated, with all-cause mortality (hazard ratio, 0.89; 95% CI, 0.85-0.94; P<.001 and hazard ratio, 0.99; 95% CI, 0.97-1.01; P=.16, respectively)., Conclusion: Maximal exercise capacity modified the relationship between BMI and long-term survival in patients with HF, upholding the presence of an exercise capacity-obesity paradox dichotomy as observed over the short-term in previous studies., (Copyright © 2018 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Background: This study evaluated if different prognostic characteristics exist for peak oxygen consumption (VO 2 ), percent predicted peak VO 2 (ppVO 2 ), and the slope of the change in minute ventilation to volume of carbon dioxide produced (V E -VCO 2 ) slope between men and women with heart failure and reduced ejection fraction (HFrEF)., Methods: Analysis of the Henry Ford Hospital Cardiopulmonary Exercise Testing database (n = 1085; 33% women, 55% black) of individuals with HFrEF who completed a physician-referred cardiopulmonary exercise testing (CPX) between 1997 and 2010. Primary outcome was a composite of all-cause death, left ventricular assist device placement, and orthotopic heart transplant . Logistic and Cox regressions were performed and Kaplan-Meier survival curves were developed to describe relationships of the CPX variables and the composite outcome within and between men and women., Results: All patients were followed-up for a minimum of 5 years, during which there were 643 combined events (62%; 499 deaths, 64 left ventricular assist device implants, 80 orthotopic heart transplant). Each CPX variable was significantly related to event-free survival among both men and women. Log-rank assessment of Kaplan-Meier curves noted survival differences for peak VO 2 and V E -VCO 2 slope (p ≤ .002), but not ppVO 2 (P = .32), between men and women., Conclusions: Prognostic values for peak VO 2 and the V E -VCO 2 slope might be considered separately for men and women, whereas the ppVO 2 value corresponding to 1- and 3-year survival rates may not be different between the sexes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Exercise capacity is associated with survival in the general population. Whether this applies to patients with treated depression is not clear., Hypothesis: High exercise capacity remains associated with lower risk of all-cause mortality (ACM) and nonfatal myocardial infraction (MI) among patients with treated depression., Methods: We included 5128 patients on antidepressant medications who completed a clinically indicated exercise stress test between 1991 and 2009. Patients were followed for a median duration of 9.4 years for ACM and 4.5 years for MI. Exercise capacity was estimated in metabolic equivalents of tasks (METs). Cox proportional hazards regression models were used., Results: Patients with treated depression who achieved ≥12 METs (vs those achieving <6 METs) were younger (age 46 ± 9 vs 61 ± 12 years), more often male (60% vs 23%), less often black (10% vs 27%), and less likely to be hypertensive (51% vs 86%), have DM (9% vs 38%), or be obese (11% vs 36%) or dyslipidemic (45% vs 54%). In the fully adjusted Cox proportional hazard regression model, exercise capacity was associated with a lower ACM (HR per 1-MET increase in exercise capacity: 0.82, 95% CI: 0.79-0.85, P < 0.001) and nonfatal MI (HR: 0.92, 95% CI: 0.87-0.97, P = 0.004)., Conclusions: Exercise capacity had an inverse association with both ACM and nonfatal MI in patients with treated depression, independent of cardiovascular risk factors. These results highlight the potential impact of assessing exercise capacity to identify risk, as well as promoting an active lifestyle among treated depression patients., (© 2018 Wiley Periodicals, Inc.)

Previous studies have demonstrated that cardiorespiratory fitness is a strong marker of cardiovascular health. Machine learning (ML) can enhance the prediction of outcomes through classification techniques that classify the data into predetermined categories. The aim of the analysis is to compare the prediction of 10 years of all-cause mortality (ACM) using statistical logistic regression (LR) and ML approaches in a cohort of patients who underwent exercise stress testing. We included 34,212 patients (55% males, mean age 54 ± 13 years) free of coronary artery disease or heart failure who underwent exercise treadmill stress testing between 1991 and 2009 and had complete 10-year follow-up. The primary outcome of this analysis was ACM at 10 years. The probability of 10-years ACM was calculated using statistical LR and ML, and the accuracy of these methods was calculated and compared. A total of 3,921 patients died at 10 years. Using statistical LR, the sensitivity to predict ACM was 44.9% (95% confidence interval [CI] 43.3% to 46.5%), whereas the specificity was 93.4% (95% CI 93.1% to 93.7%). The sensitivity of ML to predict ACM was 87.4% (95% CI 86.3% to 88.4%), whereas the specificity was 97.2% (95% CI 97.0% to 97.4%). The ML approach was associated with improved model discrimination (area under the curve for ML [0.923 (95% CI 0.917 to 0.928)]) compared with statistical LR (0.836 [95% CI 0.829 to 0.846], p<0.0001). In conclusion, our analysis demonstrates that ML provides better accuracy and discrimination of the prediction of ACM among patients undergoing stress testing., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Vascular erectile dysfunction (ED) has been identified as a potentially useful risk factor for predicting future cardiovascular events, particularly in younger men. Because these men typically score more favorably on traditional cardiovascular disease risk assessment tools, there exists a gap in knowledge for how to most appropriately identify those men who would benefit from more aggressive treatments. To date, no studies have examined the impact of fitness on cardiovascular outcomes in men with ED. This study sought to examine the prognostic impact of maximal exercise capacity on cardiovascular-related outcomes in men ages 40 to 60 years being treated for ED., Hypothesis: We hypothesized that there would be an independent association between higher baseline fitness level and lower cardiovascular events., Methods: We analyzed 1152 men with pharmacy claims file-confirmed active pharmacologic treatment for ED from the Henry Ford Exercise Testing (FIT) Project (1991-2009). All patients were free of coronary heart disease and heart failure, and underwent clinician-referred exercise stress testing, with fitness measured in metabolic equivalents of task (METs). Multivariable Cox proportional hazard models adjusted for traditional cardiovascular risk factors were used to study the association between fitness and all-cause mortality, major adverse cardiovascular events (MACE) (defined as myocardial infarction or revascularization), and incident type 2 diabetes mellitus., Results: The mean age of the population was 53 years, with 39% African Americans. In multivariable analysis, each 1 MET of fitness was associated with a 16% lower risk of death (hazard ratio [HR]: 0.84, 95% confidence interval [CI]: 0.76-0.94, P = 0.002), and a nonsignificant reduction in MACE (HR: 0.89, 95% CI: 0.79-1.003, P = 0.048), and incident diabetes (HR: 0.92, 95% CI: 0.85-1.01, P = 0.129)., Conclusions: Higher baseline fitness is associated with improved cardiovascular prognosis in a population of middle-aged men treated for ED., (© 2017 Wiley Periodicals, Inc.)

High exercise capacity (EC) has been associated with a lower risk of incident diabetes, whereas statin therapy has been associated with a higher risk. We sought to investigate whether the association between EC and diabetes risk is modified by statin therapy. This retrospective cohort study included 47,337 patients without diabetes or coronary artery disease at baseline (age 53 ± 13 years, 48% women, 66% white) who underwent clinical treadmill stress testing within the Henry Ford Health System from January 1, 1991, to May 31, 2009. The patients were stratified by baseline statin use and estimated peak METs achieved during exercise testing. Hazard ratios for incident diabetes were calculated using Cox proportional hazards models adjusted for demographic characteristics, co-morbidities, pertinent medications, and stress test indication. We observed 6,921 new diabetes cases (14.6%) over a median follow-up period of 5.1 years (interquartile interval of 2.6 to 8.2 years). Compared with the statin group, the no-statin group achieved higher mean METs (8.9 ± 2.7 vs 9.6 ± 3.0, respectively; p <0.001). After adjustment for covariates, a higher EC was associated with a lower risk of incident diabetes, irrespective of statin use (p-interaction = 0.15). Each 1-MET increment was associated with an 8%, 8%, and 6% relative risk reduction in the total cohort, the no-statin, and the statin groups, respectively (95% confidence interval, 0.91 to 0.93, 0.91 to 0.93, and 0.91 to 0.96, respectively; p <0.001 for all). We conclude that a higher EC is associated with a lower risk of incident diabetes regardless of statin use., (Copyright © 2017 Elsevier Inc. All rights reserved.)

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.

Whether lower heart rate thresholds (defined as the percentage of age-predicted maximal heart rate achieved, or ppMHR) should be used to determine chronotropic incompetence in patients on beta-blocker therapy (BBT) remains unclear. In this retrospective cohort study, we analyzed 64,549 adults without congestive heart failure or atrial fibrillation (54 ± 13 years old, 46% women, 29% black) who underwent clinician-referred exercise stress testing at a single health care system in Detroit, Michigan from 1991 to 2009, with median follow-up of 10.6 years for all-cause mortality (interquartile range 7.7 to 14.7 years). Using Cox regression models, we assessed the effect of BBT, ppMHR, and estimated exercise capacity on mortality, with adjustment for demographic data, medical history, pertinent medications, and propensity to be on BBT. There were 9,259 deaths during follow-up. BBT was associated with an 8% lower adjusted achieved ppMHR (91% in no BBT vs 83% in BBT). ppMHR was inversely associated with all-cause mortality but with significant attenuation by BBT (per 10% ppMHR HR: no BBT: 0.80 [0.78 to 0.82] vs BBT: 0.89 [0.87 to 0.92]). Patients on BBT who achieved 65% ppMHR had a similar adjusted mortality rate as those not on BBT who achieved 85% ppMHR (p >0.05). Estimated exercise capacity further attenuated the prognostic value of ppMHR (per-10%-ppMHR HR: no BBT: 0.88 [0.86 to 0.90] vs BBT: 0.95 [0.93 to 0.98]). In conclusion, the prognostic value of ppMHR was significantly attenuated by BBT. For patients on BBT, a lower threshold of 65% ppMHR may be considered for determining worsened prognosis. Estimated exercise capacity further diminished the prognostic value of ppMHR particularly in patients on BBT., Competing Interests: The authors have no relevant conflicts of interest to report, including financial interests, activities, relationships, and affiliations., (Copyright © 2016 Elsevier Inc. All rights reserved.)

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., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Given the aging population and prevalence of sedentary behaviour in the USA, we investigated the impact of differences in exercise capacity associated with age on long-term outcomes. We derived fitness-associated 'biologic age' as a tool to encourage positive lifestyle changes., Methods: This retrospective cohort study included 57085 patients without established coronary artery disease or heart failure (median age 53 years, 49% women, 29% black) who underwent clinically-referred treadmill stress testing at the Henry Ford Health System from 1991 to 2009. Patients were followed for 10.4±5 and 5.4±4 years for all-cause mortality and myocardial infarction (MI), respectively. We calculated hazard ratios associated with exercise capacity by age deciles using Cox regression models, adjusting for demographic and haemodynamic data, medical history, and medication use. Fitness-associated 'biologic age' was derived as the chronologic age with equivalent mortality or MI risk., Results: There were 6356 deaths and 1646 MIs during follow-up. Exercise capacity declined with increasing age. Higher exercise capacity was strongly associated with greater survival, with per-MET HR ranging from 0.82 (95% CI 0.78 to 0.86) in patients under 40 years of age, to 0.88 (95% CI 0.87 to 0.90) in those over 70 years of age. Biologic age varied markedly-up to three decades-within each age decile, and was a stronger predictor of mortality (C-statistic 0.81 vs 0.77) and MI (C-statistic 0.72 vs 0.68) than chronologic age., Conclusions: Higher exercise capacity remained a powerful predictor of survival despite lower average exercise capacity at older ages, reinforcing its importance in patients of all ages. Fitness-associated biologic age was a stronger predictor of survival than chronologic age, and may be a useful clinical tool for facilitating patient discussions regarding the impact of exercise capacity on long-term risk., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Objective: To examine the effect of objectively measured exercise capacity (EC) on early mortality (EM) after a first myocardial infarction (MI)., Patients and Methods: This retrospective cohort study included 2061 patients without a history of MI (mean age, 62±12 years; 38% [n=790] women; 56% [n=1153] white) who underwent clinical treadmill stress testing in the Henry Ford Health System from January 1, 1991, through May 31, 2009, and suffered MI during follow-up (MI event proportion, 3.4%; mean time from the exercise test to MI, 6.1±4.3 years). Exercise capacity was categorized on the basis of peak metabolic equivalents (METs) achieved: less than 6, 6 to 9, 10 to 11, and 12 or more METs. Early mortality was defined as all-cause mortality within 28, 90, or 365 days of MI. Multivariable logistic regression models were used to assess the effect of EC on the risk of mortality at each time point post-MI adjusting for baseline demographic characteristics, cardiovascular risk factors, medication use, indication for stress testing, and year of MI., Results: The 28-day EM rate was 10.6% overall, and 13.9%, 10.7%, 6.9%, and 6.0% in the less than 6, 6 to 9, 10 to 11, and 12 or more METs categories, respectively (P<.001). Patients who died were more likely to be older, be less fit, be nonobese, have treated hypertension, and have a longer duration from baseline to incident MI (P<.05). Adjusted regression analyses revealed a decreased risk of EM with increasing EC categories. A 1-MET higher EC was associated with an 8% to 10% lower risk of mortality across all time points (28 days: odds ratio [OR], 0.92; 95% CI, 0.87-0.98; P=.006; 90 days: OR, 0.90; 95% CI, 0.86-0.95; P<.001; 365 days: OR, 0.91; 95% CI, 0.87-0.94; P<.001)., Conclusion: Higher baseline EC was independently associated with a lower risk of early death after a first MI., (Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Decreases in systolic blood pressure during exercise may predispose to arrhythmias such as atrial fibrillation (AF) because of underlying abnormal autonomic tone. We examined the association between systolic blood pressure response and incident AF in 57,442 (mean age 54 ± 13 years, 47% women, and 29% black) patients free of baseline AF who underwent exercise treadmill stress testing from the Henry Ford ExercIse Testing project. Exercise systolic blood pressure response was examined as a categorical variable across clinically relevant categories (>20 mm Hg: referent; 1 to 20 mm Hg, and ≤0 mm Hg) and per 1-SD decrease. Cox regression, adjusting for demographics, cardiovascular risk factors, medications, history of coronary heart disease, history of heart failure, and metabolic equivalent of task achieved, was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between systolic blood pressure response and incident AF. Over a median follow-up of 5.0 years, a total of 3,381 cases (5.9%) of AF were identified. An increased risk of AF was observed with decreasing systolic blood pressure response (>20 mm Hg: HR 1.0, referent; 1 to 20 mm Hg: HR 1.09, 95% CI 0.99, 1.20; ≤0 mm Hg: HR 1.22, 95% CI 1.06 to 1.40). Similar results were obtained per 1-SD decrease in systolic blood pressure response (HR 1.08, 95% CI 1.04 to 1.12). The results were consistent when stratified by age, sex, race, hypertension, and coronary heart disease. In conclusion, our results suggest that a decreased systolic blood pressure response during exercise may identify subjects who are at risk for developing AF., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Aim: To describe the effect of the duration of the data averaging interval on the calculated peak oxygen uptake (VO2) reported from a symptom-limited maximal exercise test in patients with heart failure., Methods: Maximal exercise test results from 275 patients diagnosed with stable heart failure due to left ventricular systolic dysfunction (ejection fraction<45%; age: 45-75 years; peak VO2: 8.0-20.0mL/kg/min), were examined. Sampling rates of 10, 20, 30 and 60s were used to calculate peak VO2, which was identified as the highest interval value that occurred during the final minute of exercise or the first interval in immediate recovery., Results: Mean peak VO2 (mL/kg/min) across the four sampling periods was as follows: 14.0±3.0 (10s), 13.7±3.0 (20s), 13.5±3.0 (30s) and 13.2±2.9 (60s) and there was a significant reduction with increasing averaging duration (p<0.0001). Peak VO2 was significantly different between the 10s and 60s sampling times (p<0.0001). Peak respiratory exchange ratio (RER) was also significantly different between 10 and 60s sampling rates (p<0.0001). Sub-analyses showed peak VO2 values in those people achieving RER>1.05 to be +0.8±0.7mL/kg/min higher than those who had not achieved RER values>1.05; similar findings, +0.8±0.7mL/kg/min, were seen in those patients achieving RER>1.10 versus those who did not., Conclusions: Sampling rate method has a significant effect on calculated peak VO2 and RER. We suggest that laboratories standardize their sampling rate method to ensure consistency., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Patients with heart failure (HF) were once discouraged from participating in exercise programs because of concerns regarding safety and the potential for harm to an already damaged myocardium. However, studies over the last 3 decades have provided extensive insights into both the health outcome benefits of exercise and the mechanisms underlying these benefits. Studies on the outcome benefits of exercise training, including mortality and hospitalization, have been convincing. This article reviews the physiologic benefits of exercise training in HF, studies on exercise training in women, results and implications of the HF-ACTION trial, and recent meta-analyses using the Cochrane data base., (Published by Elsevier Inc.)

Whether resting heart rate (RHR) predicts mortality independent of fitness is not well established, particularly among women. We analyzed data from 56,634 subjects (49% women) without known coronary artery disease or atrial fibrillation who underwent a clinically indicated exercise stress test. Baseline RHR was divided into 5 groups with <60 beats/min as reference. The Social Security Death Index was used to ascertain vital status. Cox hazard models were performed to determine the association of RHR with all-cause mortality, major adverse cardiovascular events, myocardial infarction, or revascularization after sequential adjustment for demographics, cardiovascular disease risk factors, medications, and fitness (metabolic equivalents). The mean age was 53 ± 12 years and mean RHR was 73 ± 12 beats/min. More than half of the participants were referred for chest pain; 81% completed an adequate stress test and mean metabolic equivalents achieved was 9.2 ± 3. There were 6,255 deaths over 11.0-year mean follow-up. There was an increased risk of all-cause mortality with increasing RHR (p trend <0.001). Compared with the lowest RHR group, participants with an RHR ≥90 beats/min had a significantly increased risk of mortality even after adjustment for fitness (hazard ratio 1.22, 95% confidence interval 1.10 to 1.35). This relationship remained significant for men, but not significant for women after adjustment for fitness (p interaction <0.001). No significant associations were seen for men or women with major adverse cardiovascular events, myocardial infarction, or revascularization after accounting for fitness. In conclusion, after adjustment for fitness, elevated RHR was an independent risk factor for all-cause mortality in men but not women, suggesting gender differences in the utility of RHR for risk stratification., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: It is unknown if contemporary preventive treatments such as statins or primary percutaneous coronary intervention in patients with coronary heart disease (CHD) have rendered obsolete the use of measured exercise capacity for assessment of future risk and prognosis. Using a sample of patients from 2 clinical sites, most of whom were taking beta-blockade, antiplatelet, and statin therapy, we hypothesized that peak oxygen consumption (Vo(2)) would remain a strong and independent predictor of all-cause and cardiovascular-specific mortality in men and women with CHD., Methods: We studied 2,812 patients with CHD between 1996 and 2004. All-cause and cardiovascular disease-specific mortality served as end points., Results: In all men and women and in a subgroup of patients following evidence-based care, peak Vo(2) remained a strong predictor of all-cause death, with every 1 mL x kg(-1) x min(-1) increase in peak Vo(2) associated with an approximate 15% decrease in risk of death. Among men, a peak Vo(2) (mL x kg(-1) x min(-1)) below approximately 15 was associated with the highest risk, whereas a peak Vo(2) above approximately 19 was associated with a low rate and risk for annual all-cause mortality. Among women, a peak Vo(2) below approximately 12 was associated with the highest risk, whereas a peak Vo(2) above approximately 16.5 was associated with the lowest rate and risk for annual all-cause mortality., Conclusions: In men and women with CHD, peak Vo(2) remains an independent predictor of all-cause and cardiovascular-specific mortality.

Background: We are in the midst of an obesity pandemic. Morbid obesity is associated with dyspnea on exertion and higher overall mortality rates. The relations between measures of cardiorespiratory fitness in morbidly obese persons compared to those with heart failure are unknown., Methods: We compared cardiorespiratory fitness in patients with morbid obesity (n = 43) and established systolic dysfunction heart failure (n = 235), and in age-matched medical control subjects (n = 222) who had been referred for diagnostic exercise testing with simultaneous metabolic measurements. Only patients who completed an adequate test for maximum exertion manifested by a respiratory exchange ratio of > or = 1.10 were included in the study., Results: The mean (+/- SD) body mass index (BMI) values for the three groups were 47.8 +/- 5.1, 30.1 +/- 5.7, and 33.8 +/- 9.0, respectively (p < 0.0001 for comparisons between morbidly obese patients and each comparator). The mean left ventricular ejection fraction for the heart failure group was 21.5 +/- 8.4%. Despite achieving higher peak heart rate and BP values, the morbidly obese patients had a mean maximum oxygen uptake (V(O2)max) that was similar to that of those with heart failure (17.8 +/- 3.6 vs 16.5 +/- 5.6 mL/kg/min, respectively; p = 0.14) and was considerably lower than that of the control group (17.8 +/- 3.6 vs 21.3 +/- 8.2 mL/kg/min, respectively; p = 0.007). In addition, among subjects in the control group, there was a graded inverse relation between BMI and V(O2)max., Conclusions: Morbidly obese individuals have severely reduced cardiorespiratory fitness that is similar to those with established systolic dysfunction heart failure. In addition, in those persons who are referred for stress testing for medical reasons, there is an inverse graded relationship between BMI and cardiorespiratory fitness. These data suggest that the impairment in V(O2)max in morbidly obese persons is related to BMI and possibly to other factors that impair peak cardiac performance. These findings are consistent with overall higher expected mortality in morbidly obese persons.