Cardiac Rehabilitation for Patients With Heart Failure

Authors, Journal, Affiliations, Type, DOI

• Biykem Bozkurt, Gregg C. Fonarow, Lee R. Goldberg, Maya Guglin, Richard A. Josephson, Daniel E. Forman, Grace Lin, JoAnn Lindenfeld, Chris O'Connor, Gurusher Panjrath, Ileana L. Piña, Tina Shah, Shashank S. Sinha, Eugene Wolfel
• Journal of the American College of Cardiology, Vol. 77, No. 11, March 23, 2021, pp. 1454–1469
• Multi-institutional USA (Baylor, UCLA, UPenn, Indiana, Case Western, Pittsburgh, Mayo, Vanderbilt, Inova/Duke, George Washington, Wayne State, Kaiser Permanente Washington, Colorado)
• Expert Panel / Review Article — perspective from ACC HF and Transplant Section and Leadership Council; reviewed by Prevention Section Cardiac Rehabilitation Work Group
• DOI: https://doi.org/10.1016/j.jacc.2021.01.030

Overview

Cardiac rehabilitation (CR) for HF is a Class 1A recommendation in ACC/AHA guidelines, yet participation rates are only 10–30% worldwide. This JACC Expert Panel synthesizes the evidence for exercise training (ET) across HF subtypes (HFrEF and HFpEF), details how to construct an individualized exercise prescription using the FITT framework, describes the comprehensive non-exercise components of CR, and proposes structural reforms — including removal of the mandatory 6-week CMS wait period, extension of coverage to HFpEF, and expansion into home-based and telemedicine models.

Keywords

Cardiac rehabilitation; exercise training; heart failure; HF-ACTION; FITT; exercise prescription; aerobic training; HIIT; inspiratory muscle training; barriers; adherence; telemedicine

Key Takeaways

Etiology and Reversibility of Exercise Intolerance in HF

• Exercise intolerance in HF is multifactorial: inadequate cardiac output and high filling pressures → early anaerobic metabolism and muscle fatigue; skeletal muscle dysfunction (altered fiber composition, impaired oxidative capacity, reduced peripheral oxygen extraction); endothelial dysfunction; increased sympathetic activation and inflammatory cytokines; obesity
• Chronotropic incompetence is a key limiter particularly in HFpEF
• ET reverses or attenuates neurohormonal/inflammatory activation, ventricular remodeling, and improves vasomotor and endothelial function, skeletal muscle morphology, and QOL

Definition and Components of a CR Program

• CR = physician-supervised program furnishing prescribed exercise, cardiac risk factor modification, psychosocial assessment, and outcomes assessment — not exercise alone
• Core components: baseline patient assessment; nutritional counseling; lifestyle modification; risk factor management (lipids, BP, weight, diabetes, smoking); psychosocial interventions; physical activity counseling and ET
• Multidisciplinary team: physician medical director, nurses, advanced practitioners, exercise physiologists, dieticians; optional behavioral health personnel and pharmacists

Evidence by Exercise Modality

Aerobic/Moderate Continuous Training (MCT)

• Mainstay of ET; reverses LV remodeling in stable HF; improves aerobic capacity and peak VO2; modifies CV risk factors
• Familiar to patients, suitable for very low baseline fitness (<3 METs), easier for staff to implement
• More data on safety than HIIT; preferred for LVAD recipients and early post-transplant

Resistance Training

• Combined endurance + resistance significantly improves submaximal exercise capacity, muscle strength, and QOL
• Resistance training does not significantly change LVEF but improves skeletal muscle function and peripheral vascular responsiveness
• Particularly important in older adults, women, and sarcopenic patients; elastic bands suitable for home use
• Complementary to aerobic exercise — not a substitute

High-Intensity Interval Training (HIIT)

• Small studies suggested HIIT superior to MCT for reversing cardiac remodeling and increasing peak VO2
• Large multicenter trial (SMARTEX-HF): HIIT was not superior to MCT in LV remodeling or aerobic capacity
• Meta-analysis: greater improvement in exercise tolerance with HIIT, no significant LVEF difference at rest
• HIIT may be more time-efficient and improve peak VO2 to a slightly greater degree, but requires judicious patient selection and more staff
• No significant differences in withdrawal, death, or cardiac events vs MCT

Inspiratory Muscle Training

• Widespread inspiratory muscle weakness in HF from mechanical, metabolic, and oxidative stress mechanisms
• Beneficial in stable HF with respiratory muscle weakness: improves respiratory muscle strength and dyspnea in both HFrEF and HFpEF
• Meta-analysis: improvements in 6-min walk distance, peak VO2, and minute ventilation vs sham/control
• Addition to aerobic training reduces dyspnea, increases peak VO2 and exercise time, and improves QOL

Localized Muscle Training

• Small-muscle exercise improves muscle structure, diffusive oxygen transport, and oxygen utilization without requiring increased cardiac output
• Particularly useful in severely disabled patients with minimal reserve capacity

Developing an Exercise Prescription

• FITT framework: Frequency, Intensity, Time, Type
• Target: aerobic medium-intensity continuous ET (50–80% of peak capacity) for up to 45 min on most days of the week in clinically stable patients
• HF-ACTION protocol:
  • Baseline cardiopulmonary exercise testing (modified Naughton protocol); Borg scale target ≥16; respiratory exchange ratio >1.05
  • Initial 6 supervised sessions: 60% heart rate reserve (HRR); patients unable to exercise continuously start at 50% HRR for 15–30 min with rest periods
  • Remaining 36 supervised sessions: 60–70% HRR
  • Home maintenance: 40 min aerobic exercise, 5×/week; 10-min warm-up and cool-down
  • For AF or frequent ectopy: Borg scale used instead of heart rate reserve
  • For beta-blocker patients unable to reach target HR: Borg 12–14
  • Exercise-induced ischemia/angina: target HR 10 bpm below ischemic threshold
• Lifestyle exercise for those not in formal CR: MCT starting at <60% HRR or resting HR +30 bpm, increasing duration every 2–4 weeks to 45 min, then increasing intensity
• Monitoring: symptoms, NYHA class, QOL, peak VO2 on CPET, or 6-min walk distance

Non-Exercise Components of CR

• Nutrition: individualized dietary counseling; assess caloric adequacy and protein (especially in sarcopenic/obese patients); validated dietary questionnaires; registered dietician nutritionist is ideal
• Lifestyle modification: physical activity, avoiding obesity, smoking cessation, healthy diet, cholesterol control, blood pressure and glucose normalization
• Psychosocial: screening for depression (Beck Depression Inventory, Patient Health Questionnaire), anxiety, and mild cognitive dysfunction at baseline and intervals during program; group education on affective components; referral for severe depression

Guideline Recommendations and Coverage Criteria

• ACC/AHA HF guidelines: CR = Class I, Level of Evidence A for ambulatory, symptomatic (Stage C) NYHA II–III HF on GDMT
• CMS coverage criteria: LVEF ≤35%, NYHA class II–IV, despite ≥6 weeks of optimal therapy; up to 36 sessions; stability = no major CV hospitalization/procedure in preceding 6 weeks or planned within 6 months
• No CMS coverage for HFpEF despite evolving evidence

Evidence in HFrEF

• ET improves central hemodynamics, peripheral vascular/endothelial function, skeletal muscle oxidative capacity, sympathetic/neurohormonal activation, vagal tone, and circulating NT-proBNP
• LVEF improvements modest and inconsistent across trials; LVEF should not be overemphasized as a target or marker for benefit
• Most patients improve functional capacity without LVEF change
• QOL improves significantly, including physical and social limitations (HF-ACTION: early 3-month gains persisted throughout follow-up)
• Peak VO2: ~15–17% improvement with ET
• HF hospitalization reduced in meta-analyses; mortality reduction suggested with longer follow-up and in adherent patients

Evidence in HFpEF

• Consistent evidence for improved exercise capacity and health-related QOL
• Some studies show atrial reverse remodeling and improved LV diastolic function; others show no change in LV function, compliance, volumes, or arterial stiffness
• CMS does not yet cover CR for HFpEF; evidence is evolving

Evidence After HF Hospitalization

• EJECTION-HF trial: supervised center-based ET safe and feasible after acute HF hospitalization but did not reduce death or readmission
• REHAB-HF trial (ongoing): balance, mobility, strength, and endurance ET in older patients hospitalized for HF

Evidence in Advanced/Stage D HF

• Insufficient data for active NYHA class IV or stage D; advanced NYHA III: long-term ET improved stroke volume and reduced cardiomegaly
• LVAD patients: Rehab-VAD trial showed moderate-intensity aerobic training was safe, improved health status, treadmill time, leg strength — no significant peak VO2 improvement
• Post-cardiac transplant: emerging evidence for ET benefit

Barriers to CR Implementation

• Provider/system: lack of awareness, trained staff, and facilities; poor reimbursement; prescribing restricted to cardiologists
• Patient: psychosocial factors, economic barriers, travel, time from work, poor social support; women, minorities, and elderly disproportionately under-referred
• Policy: mandatory 6-week waiting period before referral; no HFpEF coverage; copayments prohibitive; novel care models not yet reimbursed

Future Directions and Proposed Changes

• Remove mandatory 6-week CMS wait; allow concurrent optimization of GDMT and CR
• Automatic referral via EHR doubles enrollment
• Expand coverage to HFpEF and recently hospitalized patients
• Include new CR models in reimbursement: home-based, telemedicine, hybrid, community-based
• Wearable technology and activity monitoring via implanted devices to reduce recidivism
• Newer exercise modalities: shorter HIIT bursts, inspiratory muscle training, yoga, tai chi as complementary

Limitations of the Document

• Expert panel consensus / review — not a primary RCT; evidence base for several recommendations (especially HFpEF, HIIT, advanced HF) is limited
• HIIT recommendations based largely on small studies; one large multicenter trial (SMARTEX-HF) showed no superiority over MCT
• HF-ACTION was restricted to HFrEF (LVEF ≤35%); long-term adherence <30% even in trial setting
• CMS coverage discussion reflects 2020–2021 US policy landscape
• Only 8–15% of prior ET RCTs sufficiently described exercise protocols, limiting evidence synthesis

Key Concepts Mentioned

• concepts/Cardiac-Rehabilitation-HF — comprehensive CR program for HF; main concept generated from this source
• concepts/Cardiopulmonary-Exercise-Testing — used for baseline evaluation and exercise prescription development in CR
• concepts/Iron-Deficiency-in-HF — nutritional consideration in CR program planning
• concepts/HF-COPD-Comorbidity — COPD coexistence affects ET tolerance and prescription
• concepts/CAM-in-Heart-Failure — yoga, tai chi mentioned as complementary exercise modalities in CR

Key Entities Mentioned

• HF-ACTION trial — largest RCT of ET in HFrEF; backbone of CR evidence
• EJECTION-HF trial — supervised ET after acute HF hospitalization; safe but neutral on death/readmission
• REHAB-HF trial — ongoing; physical function intervention in older hospitalized HF patients
• Rehab-VAD trial — moderate-intensity aerobic training in LVAD patients; improved health status/treadmill time
• SMARTEX-HF — large multicenter trial: HIIT not superior to MCT for LV remodeling or aerobic capacity

Wiki Pages Updated

• wiki/sources/crp-hf-jacc-2021.md — created (this file)
• wiki/concepts/Cardiac-Rehabilitation-HF.md — created
• wiki/concepts/Cardiopulmonary-Exercise-Testing.md — updated (added CR context)
• wiki/wikiindex.md — updated
• wiki/sourceindex.md — updated
• log.md — updated