Role of Left Ventricle Function in Cardiac Rehabilitation Outcomes in Stage B Heart Failure Patients Purpose: To study the role of left ventricle systolic function in cardiac rehabilitation program (CRP) response in stage B heart failure patients. Methods: A retrospective analysis was completed of 691 patients with previous myocardial infarction that underwent a CRP, classified in 3 groups: preserved ejection fraction (pEF), mid-range ejection fraction (mrEF), and reduced ejection fraction (rEF). We compared the response to CRP analyzing the relative changes of estimated cardiorespiratory fitness (CRFe), resting heart rate (HR), and chronotropic index (CI). Results: After exercise training (median [interquartile range]) mrEF (23.9% [9.7, 40.8]) and rEF (23.9% [9.7, 41.2]) groups had a better CRFe response to CRP than pEF groups (17.6% [0.0, 35.9]), P = .009. CI increased similarly in all groups. We found a small effect of CRP on resting HR. Conclusion: Exercise-based CRP yields notable benefits to mrEF and rEF groups and the magnitude of its benefits is, at least, similar to that found in pEF patients. Correspondence: Marta Braga, MD, Serviço de Cardiologia, Centro Hospitalar São João, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal (martabraga.hsj@gmail.com). Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.jcrpjournal.com). The authors declare no conflicts of interest. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Physiological Responses to the 6-min Step Test in Patients With Chronic Obstructive Pulmonary Disease Purpose: To describe physiological responses during the 6-min step test (6MST) in patients with chronic obstructive pulmonary disease (COPD), to investigate whether COPD severity and test interruptions could determine different physiological responses, and to test the reproducibility of 6MST performance. Methods: Cross-sectional study. Patients with moderate to very severe COPD underwent lung function assessment and 2 6MSTs, with physiological responses measurement by a gas analyzer and a near-infrared spectroscopy device. Results: Thirty-six patients (29 men; forced expiratory volume in the first second of expiration [FEV1] = 51.1 ± 13.6%pred) participated in the study. Most of the physiological variables stabilized between the second and fourth minutes of the 6MST, except the respiratory rate and heart rate (HR), which stabilized after the fifth minute. The patients who interrupted the 6MST showed higher minute ventilation to maximal voluntary ventilation ratio (VE/MVV; all test minutes) and HR (first and second minutes) (P < .05) and worse pulmonary function (FEV1 = 1.37 ± 0.37 L vs 1.82 ± 0.41 L, P = .002, and 47.2 ± 13.2%pred vs 56.6 ± 12.4%pred, P = .04, respectively) than those who did not interrupt the 6MST. However, their performance was similar (P = .11). 6MST performance and physiological variables were reproducible, and there was a learning effect of 6.28%. Conclusions: The 6MST showed a stabilization of the most physiological variables. In addition, interruptions were usually made by patients with a greater impairment of lung function and they presented greater increased ventilatory demand during the 6MST. However, these interruptions do not interfere with 6MST physiological responses. Moreover, the 6MST is a reliable test to evaluate the functional capacity of patients with COPD. Correspondence: Anamaria F. Mayer, PhD, Núcleo de Assistência, Ensino e Pesquisa em Reabilitação Pulmonar—NuReab, Universidade do Estado de Santa Catarina, Rua Pascoal Simone, 358. CEP 88080-350, Florianópolis-SC, Brazil (anamaria.mayer@udesc.br). The authors certify that there are no conflicts of interest with any financial organization regarding the material discussed in this article. All authors have read and approved the manuscript. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Effect of Home-Based Cardiac Rehabilitation in a Lower-Middle Income Country: RESULTS FROM A CONTROLLED TRIAL Purpose: Cardiovascular disease is the leading cause of mortality and morbidity in lower-middle income countries (LMICs), including Bangladesh. Cardiac rehabilitation (CR) as part of secondary prevention of cardiovascular disease has been shown to reduce mortality and morbidity and improve quality of life and exercise capacity. However, to date, very few controlled trials of CR have been conducted in LMICs. Methods: A quasi-randomized controlled trial comparing home-based CR plus usual care with usual care alone was undertaken with patients following coronary artery bypass graft surgery. Participants in the CR group received an in-hospital CR class and were introduced to a locally developed educational booklet with details of a home-based exercise program and then received monthly telephone calls for 12 mo. Primary outcomes were coronary heart disease (CHD) risk factors, health-related quality of life (HRQOL), and mental well-being. Maximal oxygen uptake as a measure of exercise capacity was a secondary outcome. Results: In total, 142 of 148 eligible participants took part in the trial (96%); 71 in each group. At 12-mo follow-up, 61 patients (86%) in the CR group and 40 (56%) in the usual care group provided complete outcome data. Greater reductions in CHD risk factors and improvements in HRQOL, mental well-being, and exercise capacity were seen for the CR group compared with the usual care group. Conclusions: In the context of a single-center LMIC setting, this study demonstrated the feasibility of home-based CR programs and offers a model of service delivery that could be replicated on a larger scale. Correspondence: Vicky L. Joshi, MSc, Danish Knowledge Centre for Rehabilitation and Palliative Care (REHPA), Odense University Hospital and University of Southern Denmark, Studiestrade 6, 1455, Copenhagen, Denmark (victoria.louise.joshi@rsyd.dk). All authors have read and approved the manuscript. The authors declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.jcrpjournal.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Diagnostic Validity of Cardiopulmonary Exercise Testing for Screening Pulmonary Hypertension in Patients With Chronic Obstructive Pulmonary Disease Purpose: To determine diagnostic validity of cardiopulmonary exercise testing (CPX) parameters for detecting pulmonary hypertension (PH) in patients with chronic obstructive pulmonary disease (COPD) and to investigate association between CPX parameters and indices of PH. Methods: This cross-sectional study enrolled 48 moderate to very severe COPD patients in whom PH was confirmed by echocardiography. Symptom-limited CPX was performed using an incremental exercise protocol. Relevant CPX parameters were derived and were tested for their diagnostic ability for diagnosing PH. Logistic regression was applied to examine the effect of various clinical covariates on the diagnostic ability of exercise test variables for detecting PH. Results: Of the 48 patients, 29 were diagnosed with PH and 19 were negative for PH based on echocardiographic testing. CPX measures including peak oxygen uptake (% predicted VO2peak, VO2peak [mL/min], VO2/kg), oxygen pulse (VO2/HR % predicted, VO2/HR mL/beat), and peak minute ventilation (VEpeak [L/m]) were inversely correlated with mean pulmonary arterial pressure (mPAP). Peak VO2/HR and VO2peak were found to be significant predictors of PH in univariate analysis. VO2peak (%), VO2/HR (mL/beat), and desaturation (%) were identified as independent predictors of PH adjusted for age, forced expiratory volume in 1 sec (%), and forced vital capacity (L). Conclusion: The present study validates the use of CPX parameters such as VO2peak and VO2/HR as a diagnostic tool for correctly identifying PH in COPD patients. Therefore, CPX may be used as an adjunct to echocardiographic measurement of PH where there is unavailability of equipment and expertise. Correspondence: Jamal Ali Moiz, PhD, MPT, Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia, New Delhi 110 025, India (jmoiz@jmi.ac.in). Conflict of Interest: None. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Type 2 Diabetes Mellitus, Glycated Hemoglobin Levels, and Cardiopulmonary Exercise Capacity in Patients With Ischemic Heart Disease Purpose: Diabetes mellitus (DM) is associated with long-term cardiovascular complications, including ischemic heart disease (IHD). Nonetheless, DM may directly impair myocardial and lung structure and function. The aim of this study was to assess the impact of type 2 DM (T2DM) and glycemic control on cardiopulmonary exercise capacity in patients with IHD. Methods: The study involved a cross-sectional analysis of 91 consecutive patients (57 ± 10 yr, 90% men) who underwent a cardiopulmonary exercise test at the beginning of an exercise-based standard phase-II cardiac rehabilitation program, 2 to 3 mo after an acute coronary syndrome. Association of T2DM with cardiopulmonary exercise test parameters was assessed using multiple linear regression analysis controlling for prespecified potential confounders. Results: There were 26 (29%) diabetic subjects among IHD patients included in the study. After adjustment, T2DM was an independent predictor of a reduced peak oxygen uptake (VO2peak) (P = .005), a reduced pulse O2 trajectory (P = .001), a steeper minute ventilation to carbon dioxide output (VE/VCO2) slope (P = .046), and an increased dead space-to-tidal volume ratio (VD/VT) at peak exercise (P = .049). Glycated hemoglobin (HbA1c) levels were significantly associated with a reduced forced expiratory volume in the first second of expiration (FEV1) (P = .013), VE (P = .001), and VT (P = .007). VO2peak (P trend < .001), VO2 at anaerobic threshold (P trend < .001), and pulse O2 trajectory (P trend < .001) decreased among HbA1c tertiles. Conclusions: Patients with IHD and a previous diagnosis of T2DM had a reduced aerobic capacity and a ventilation-perfusion mismatch compared with nondiabetic patients. Poor glycemic control in men further deteriorates aerobic capacity probably due to ventilatory inefficiency. Correspondence: Ramón Arroyo-Espliguero, MD, PhD, Department of Cardiology, University Hospital, Guadalajara, Spain, C/Donantes de Sangre, s/n Guadalajara, 19002 (rarroyo@sescam.jccm.es). The authors report no relationships with respect to the research, authorship, and/or publication of this article that could be construed as a conflict of interest. Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal's Web site (www.jcrpjournal.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

The Effect and Safety of Aerobic Interval Training According to Exercise Intensity in Acute Coronary Syndrome Purpose: To evaluate the effect of increasing the maximal oxygen uptake (VO2max) and the safety of maximal-intensity aerobic interval training (MAIT) compared with high-intensity aerobic interval training (HAIT). Methods: Forty-seven patients with first-ever acute coronary syndrome were assigned to MAIT or HAIT. Subjects underwent adaptation period during the first 2 wk of cardiac rehabilitation and then MAIT at 95-100% of the heart rate reserve or HAIT at 85% of the heart rate reserve, 3 d/wk for 4 wk. The primary outcome was VO2max. The secondary outcomes were major cardiovascular complications, hemodynamic responses, myocardial oxygen demand, cardiometabolic health, and echocardiographic findings. Results: A total of 670.5 hr of MAIT and HAIT were completed. After 6 wk of aerobic interval training, VO2max was significantly increased in both groups. However, the increment of VO2max was significantly greater in the MAIT group than in the HAIT group (P < .05). The percentage increases for MAIT and HAIT were 31% and 17%, respectively. No major cardiovascular or musculoskeletal complications were noted. Conclusions: The results of this study indicate that 6 wk of MAIT resulted in statistically significantly better improvement in VO2max than 6 wk of HAIT at a similar total work in patients with acute coronary syndrome. Moreover, both MAIT and HAIT may be safe to use in the cardiac rehabilitation setting. Correspondence: Hee Eun Choi, MD, Department of Rehabilitation Medicine, Haeundae Paik Hospital, Inje University College of Medicine, 875, Haeun-daero, Haeundae-gu, Busan, Korea (solideogloria@paik.ac.kr). The authors declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.jcrpjournal.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Pedometer Feedback Interventions Increase Daily Physical Activity in Phase III Cardiac Rehabilitation Participants Purpose: To determine the effects of individually tailored interventions designed to increase physical activity (PA) in cardiac patients. Methods: A total of 99 (77 men and 22 women, 61.5 ± 10.7 yr) patients entering a phase III cardiac rehabilitation program completed a 12-wk PA intervention. Patients were randomized to usual care (UC, time-based recommendation), pedometer feedback (PF), newsletter-based motivational messaging (MM), or PF + MM. Both PF groups were given a goal of increasing steps/d by 10% of individual baseline value each week. If the goal for the week was not reached, the same goal was used for the next week. Physical activity was assessed for 7 d before beginning and after completing the program. The change in steps/d, moderate to vigorous intensity PA minutes, and sedentary time were compared among intervention groups. Results: Average change in steps/d was found to be significantly greater (P < .01) in the PF (2957 ± 3185) and the PF + MM (3150 ± 3007) compared with UC (264 ± 2065) and MM (718 ± 2415) groups. No group experienced changes in moderate to vigorous intensity PA time and only the PF intervention group decreased sedentary time (baseline 470.2 ± 77.1 to postintervention 447.8 ± 74.9 min/d, P = .01). Conclusion: The findings from this study demonstrate that using PF was superior to the usual time–based PA recommendations and to newsletter-based MM in patients starting a phase III CR program. Cardiac rehabilitation programs are encouraged to implement PA feedback with individualized PA goals in order to support the increase in PA. Correspondence: Cemal Ozemek, PhD, FACSM, ACSM-CEP, RCEP, Department of Physical Therapy, College of Applied Health Sciences, The University of Illinois at Chicago, 1919 W Taylor St, Chicago, IL 60612 (ozemek@uic.edu). The authors declare no conflicts of interest. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Low-Volume High-Intensity Aerobic Interval Training Is an Efficient Method to Improve Cardiorespiratory Fitness After Myocardial Infarction: PILOT STUDY FROM THE INTERFARCT PROJECT Purpose: To analyze the changes in cardiorespiratory fitness (CRF) and body composition following 2 different (low-volume vs high-volume) high-intensity aerobic interval training (HIIT) programs with Mediterranean diet (Mediet) recommendations in individuals after myocardial infarction (MI) and compared with an attention control group (AC). Methods: Body composition and CRF were assessed before and after a 16-wk intervention in 70 participants (58.4 ± 8.5 yr) diagnosed with MI. All participants received Mediet recommendations and were randomly assigned to the AC group (physical activity recommendations, n = 14) or one of the 2 supervised aerobic exercise groups (2 d/wk training): high-volume (40 min) HIIT (n = 28) and low-volume (20 min) HIIT (n = 28). Results: Following the intervention, no significant changes were seen in the AC group and no differences between HIIT groups were found in any of the studied variables. Only HIIT groups showed reductions in waist circumference (low-volume HIIT, Δ=−4%, P < .05; high-volume HIIT, Δ=−2%, P < .001) and improvements in CRF (low-volume HIIT, Δ= 15%, P < .01; high-volume HIIT, Δ= 22%; P < .001) with significant between-group differences (attention control vs HIIT groups). Conclusions: Results suggest that a 16-wk intervention (2 d/wk) of different HIIT volumes with Mediet recommendations could equally improve CRF and waist circumference after MI. Low-volume HIIT may be a potent and time-efficient exercise training strategy to improve functional capacity. Correspondence: Sara Maldonado-Martín, PhD, Physical Activity and Sport Science Section, Department of Physical Education and Sport, Faculty of Education and Sport, University of the Basque Country (UPV/EHU), Portal de Lasarte, 71, 01007 Vitoria-Gasteiz (Araba/Alava)-Basque Country, Spain (sara.maldonado@ehu.eus). The authors declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.jcrpjournal.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Effect of Initiating Cardiac Rehabilitation After Myocardial Infarction on Subsequent Hospitalization in Older Adults Purpose: Outpatient cardiac rehabilitation (CR) participation after myocardial infarction (MI) reduces all-cause mortality; however, less is known about effects of CR on post-MI hospitalization. The study objective was to investigate effects of CR on hospitalization following acute MI among older adults. Methods: Medicare beneficiaries aged 65 to 88 yr hospitalized in 2008 with acute MI, who survived at least 60 d post-discharge, had a revascularization procedure during index hospitalization, and did not have an MI in previous year were eligible for this study. CR initiation was assessed in the 60 d post-discharge. Competing risk survival analysis was used to estimate the proportion of discharged beneficiaries hospitalized between the end of 60-d exposure window and December 31, 2009, treating death as a competing event. Results: The mean ± SD age of 32 851 Medicare beneficiaries meeting study criteria was 75 ± 6.0 yr, approximately half were male (52%), and the majority were white (88%). In this study, 21% of beneficiaries initiated CR within the exposure window. At 1 yr post-discharge, CR initiators had a lower risk of recurrent MI (4.2% [95% CI, 3.5-5.1]), cardiovascular (15.7% [95% CI, 14.3-17.2]), and all-cause (30.4% [95% CI, 28.8-32.1]) hospitalization than noninitiators (5.2% [95% CI, 5.0-5.5]; 18.0% [95% CI, 17.6-18.4]; and 33.2% [95% CI, 32.5-33.8], respectively). There was no difference in fracture risk (negative control outcome). Conclusions: This study provides evidence that CR can reduce the 1-yr risk of cardiovascular and all-cause hospital admissions in Medicare aged MI survivors. Correspondence: Montika Bush, PhD, Department of Emergency Medicine, School of Medicine, University of North Carolina, Chapel Hill, 170 Manning Dr, CB# 7594, Chapel Hill, NC 27599 (mbush8@unc.edu). Dr Stürmer receives investigator-initiated research funding and support as Principal Investigator (R01 AG056479) from the National Institute on Aging and as coinvestigator (R01 HL118255, R01 MD011680) from the National Institutes of Health (NIH). He also receives salary support as Director of Comparative Effectiveness Research (CER), NC TraCS Institute, UNC Clinical and Translational Science Award (UL1TR002489), the Center for Pharmacoepidemiology (current members: GlaxoSmithKline, UCB BioSciences, Merck, Takeda), from pharmaceutical companies (GSK, Amgen, AstraZeneca, Novo Nordisk), and from a generous contribution from Dr Nancy A. Dreyer to the Department of Epidemiology, University of North Carolina at Chapel Hill. Dr Stürmer does not accept personal compensation of any kind from any pharmaceutical company. He owns stock in Novartis, Roche, BASF, AstraZeneca, and Novo Nordisk. Dr Brookhart has received investigator-initiated research funding and support as Principal Investigator (NIH, R21 HD080214, R01 AG023178, R01 AG056479); as co-Investigator from the Agency for Healthcare Research, Patient Centered Outcomes Research Institute, AstraZeneca, and Amgen; honoraria paid via UNC for scientific advisory from Merck, GSK, Pfizer, and World Health Information Consultants; and consulting fees from RxAnte. The author others declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.jcrpjournal.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.

Characterization of Dyspnea in Veteran Lung Cancer Survivors Following Curative-Intent Therapy Purpose: Dyspnea is highly prevalent in lung cancer survivors following curative-intent therapy. We aimed to identify clinical predictors or determinants of dyspnea and characterize its relationship with functional exercise capacity (EC). Methods: In an analysis of data from a cross-sectional study of lung cancer survivors at the VA San Diego Healthcare System who completed curative-intent therapy for stage I-IIIA disease ≥1 mo previously, we tested a thorough list of comorbidities, lung function, and lung cancer characteristics. We assessed dyspnea using the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Lung Cancer Module 13 (LC13) and functional EC using the 6-minute walk. We replicated results with the University of California San Diego Shortness of Breath Questionnaire. Results: In 75 participants at a median of 12 mo since treatment completion, the mean ± SD LC13-Dyspnea score was 35.3 ± 26.2; 60% had abnormally high dyspnea. In multivariable linear regression analyses, significant clinical predictors or determinants of dyspnea were (β [95% CI]) psychiatric illness (−20.8 [−32.4 to −9.09]), heart failure with reduced ejection fraction (−15.5 [−28.0 to −2.97]), and forced expiratory volume in the first second of expiration (−0.28 [−0.49 to −0.06]). Dyspnea was an independent predictor of functional EC (−1.54 [−2.43 to −0.64]). These results were similar with the University of California San Diego Shortness of Breath Questionnaire. Conclusion: We identified clinical predictors or determinants of dyspnea that have pathophysiological bases. Dyspnea was independently associated with functional EC. These results have implications in efforts to reduce dyspnea and improve exercise behavior and functional EC in lung cancer survivors following curative-intent therapy. Correspondence: Duc Ha, MD, MAS; Institute for Health Research, Kaiser Permanente Colorado, 2550 S Parker Rd Ste 200, Aurora, CO 80014 (duc.m.ha@kp.org). This work was supported directly by the American Cancer Society (PF-17-020-01-CPPB) and the National Institutes of Health (1T32HL134632-01 from the NHLBI) and indirectly by the National Cancer Institute (L30CA208950). The authors declare no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.jcrpjournal.com). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.