The Role of Cardiac Rehabilitation in Reducing Major Adverse Cardiac Events in Heart Transplant Patients

Exercise as a modality to improve heart transplantation-related functional impairments: An article review

Heart transplantation (HT), the treatment choice of advanced heart failure patients, is proven effective in increasing the survival and functional status of the recipients. However, compared to normal controls, functional status is lower in HT recipients. Exercise given in cardiac rehabilitation has been shown to improve exercise capacity as measured with peak oxygen uptake (VO2 peak) and muscle strength after completion of the program and cessation of exercise results in loss of exercise benefits. Several factors related to cardiac denervation and the use of immunosuppressive agents in HT recipients result in functional impairments including cardiovascular, pulmonary, exercise capacity, psychological, and quality of life (QoL) problems. High-intensity interval training (HIIT) is the most common type of exercise used in HT recipients and given as a hospital-based program. Improvement of functional impairments was found to have occurred due to primarily musculoskeletal adaptations through improvement of muscle structure and aerobic capacity and cardiovascular adaptations. In general, exercise given after transplantation improved VO2 peak significantly and improvement was better in the HIIT group compared to moderate intensity continuous training or no-exercise groups. Improvement of QoL was ascribed to improvement of exercise capacity, symptoms, pulmonary function, physical capacity improvement, anxiety, and depression.

Inorganic Nitrite to Amplify the Benefits and Tolerability of Exercise Training in Heart Failure With Preserved Ejection Fraction: The INABLE-Training Trial

OBJECTIVE

To determine whether nitrite can enhance exercise training (ET) effects in heart failure with preserved ejection fraction (HFpEF).

METHODS

In this multicenter, double-blind, placebo-controlled, randomized trial conducted at 1 urban and 9 rural outreach centers between November 22, 2016, and December 9, 2021, patients with HFpEF underwent ET along with inorganic nitrite 40 mg or placebo 3 times daily. The primary end point was peak oxygen consumption (VO2). Secondary end points included Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OSS, range 0 to 100; higher scores reflect better health status), 6-minute walk distance, and actigraphy.

RESULTS

Of 92 patients randomized, 73 completed the trial because of protocol modifications necessitated by loss of drug availability. Most patients were older than 65 years (80%), were obese (75%), and lived in rural settings (63%). At baseline, median peak VO2 (14.1 mL·kg-1·min-1) and KCCQ-OSS (63.7) were severely reduced. Exercise training improved peak VO2 (+0.8 mL·kg-1·min-1; 95% CI, 0.3 to 1.2; P<.001) and KCCQ-OSS (+5.5; 95% CI, 2.5 to 8.6; P<.001). Nitrite was well tolerated, but treatment with nitrite did not affect the change in peak VO2 with ET (nitrite effect, -0.13; 95% CI, -1.03 to 0.76; P=.77) or KCCQ-OSS (-1.2; 95% CI, -7.2 to 4.9; P=.71). This pattern was consistent across other secondary outcomes.

CONCLUSION

For patients with HFpEF, ET administered for 12 weeks in a predominantly rural setting improved exercise capacity and health status, but compared with placebo, treatment with inorganic nitrite did not enhance the benefit from ET.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02713126.

Impairments identified by comprehensive geriatric assessment in potential candidates for left ventricular assist device and heart transplantation

Background

The aim of this study was to assess the prevalence of frailty and other impairments in potential left ventricular assist device (LVAD) and heart transplantation (HTx) candidates by performing a preoperative comprehensive geriatric assessment (CGA) and reviewing the treatment recommendations resulting from the CGA.

Methods and results

This cross-sectional study included 73 patients aged ≥40 years who received a CGA as part of the patient selection procedure for LVAD and HTx. In every patient, a conclusion comprising frailty and other impairments was formulated based on the medical, mental, functional, and social domains and recommendations were made. The mean age was 58 years (range 40-71) and 70 % were male. In 97 % of patients, at least one impairment was identified by the CGA. The most common impairments were polypharmacy, high morbidity burden, reduced renal function, osteopenia, depression, poor quality of life, reduced functionality, (risk of) malnutrition, reduced grip strength and high caregiver burden. A small proportion of the potential LVAD and HTx candidates were frail (7 % according to Fried's frailty criteria, 6 % according to the Edmonton Frail Scale) and 39 % were pre-frail. The domains for which most impairments were found and the domains for which most treatment recommendations were given matched well, with the functional domain as the frontrunner.

Conclusion

This study showed that most of the potential candidates for LVAD or HTx have impairments on at least one domain of the CGA. Impairments and associated risks can contribute to the decision making process for candidacy for LVAD and HTx.

The Exercise aNd hEArt transplant (ENEA) trial - a registry-based randomized controlled trial evaluating the safety and efficacy of cardiac telerehabilitation after heart transplant

BACKGROUND

Heart transplant (HTx) is gold-standard therapy for patients with end-stage heart failure. Cardiac rehabilitation (CR) is a multidisciplinary intervention shown to improve cardiovascular prognosis and quality of life. The aim in this randomized controlled trial is to explore the safety and efficacy of cardiac telerehabilitation after HTx. In addition, biomarkers of rehabilitation outcomes will be identified, as data that will enable treatment to be tailored to patient phenotype.

METHODS

Patients after HTx will be recruited at IRCCS S. Maria Nascente - Fondazione Don Gnocchi, Milan, Italy (n = 40). Consenting participants will be randomly allocated to either of two groups (1:1): an intervention group who will receive on-site CR followed by 12 weeks of telerehabilitation, or a control group who will receive on-site CR followed by standard homecare and exercise programme. Recruitment began on 20th May 2023 and is expected to continue until 20th May 2025. Socio-demographic characteristics, lifestyle, health status, cardiovascular events, cognitive function, anxiety and depression symptoms, and quality of life will be assessed, as well as exercise capacity and muscular endurance. Participants will be evaluated before the intervention, post-CR and after 6 months. In addition, analysis of circulating extracellular vesicles using Surface Plasmon Resonance imaging (SPRi), based on a rehabilomic approach, will be applied to both groups pre- and post-CR.

CONCLUSION

This study will explore the safety and efficacy of cardiac telerehabilitation after HTx. In addition, a rehabilomic approach will be used to investigate biomolecular phenotypization in HTx patients.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT05824364.

Intensive Versus Traditional Cardiac Rehabilitation: Mortality and Cardiovascular Outcomes in a 2016-2020 Retrospective Medicare Cohort

BACKGROUND

Traditional cardiac rehabilitation (CR) improves cardiovascular outcomes and reduces mortality, but less is known about the relative benefit of intensive CR (ICR) which incorporates greater lifestyle education through 72 sessions (versus 36 in CR). Our objective was to determine whether ICR is associated with a mortality and cardiovascular benefit compared with CR.

METHODS

Retrospective cohort study of Medicare Fee-For-Service beneficiaries in a 100% sample, claims data set. Qualifying events were captured from May 1, 2016 to December 31, 2019 and ICR/CR utilization captured from May 1, 2016 to December 31, 2020. Among patients attending at least 1 day of either CR or ICR, Cox proportional hazards models using a 1 to 5 propensity score match were used to compare utilization and the association of ICR versus CR participation with (1) all-cause mortality and (2) cardiovascular-related hospitalizations or nonfatal cardiac events. Dose-response was assessed by the number of days attended.

RESULTS

From 2016 to 2019, 1 277 358 unique patients met at least one qualifying indication for ICR/CR from 2016 to 2019. Of these, 262 579 (20.6%) and 4452 (0.4%) attended at least one session of CR or ICR, respectively (mean [SD] age, 73.2 [7.8] years; 32.3% female). In the matched sample, including 26 659 total patients (median, 2.4-year follow-up), ICR was associated with 12% lower all-cause mortality (multivariable adjusted hazard ratio, 0.88 [95% CI, 0.78-0.99]; P=0.036) compared with CR but no significant difference for cardiovascular-related hospitalization or nonfatal cardiac events. The mortality benefit was seen for both ICR and CR per day strata, with each modality demonstrating a clear dose-response benefit.

CONCLUSIONS

ICR is associated with lower mortality than traditional CR among Medicare beneficiaries but no difference in cardiovascular-related hospitalization or nonfatal cardiac events. Moreover, ICR and CR demonstrate a dose-response relationship for mortality. Additional studies are needed to confirm these observations and to better understand the mechanisms by which ICR may lead to a reduction in mortality.

Evaluating a Telemedicine Video Game-Linked High-Intensity Interval Training Exercise Programme in Paediatric Heart Transplant Recipients

Paediatric heart transplant recipients (HTRs) have reduced exercise capacity, physical activity (PA), health-related quality of life (HRQoL), and self-efficacy towards PA. Exercise interventions have demonstrated improvements in exercise capacity and functional status in adult HTRs, with a specific emerging interest in the role of high-intensity interval training (HIIT). Studies of exercise interventions in paediatric HTRs have been limited and nonrandomized to date. HIIT has not yet been evaluated in paediatric HTRs. We thus seek to evaluate the safety and feasibility of a randomized crossover trial of a 12-week, home-based, video game-linked HIIT intervention using a cycle ergometer with telemedicine and remote physiological monitoring capabilities (MedBIKE) in paediatric HTRs. The secondary objective is to evaluate the impact of the intervention on (1) exercise capacity, (2) PA, (3) HRQoL and self-efficacy towards PA, and (4) sustained changes in secondary outcomes at 6 and 12 months after intervention. After a baseline assessment of the secondary outcomes, participants will be randomized to receive the MedBIKE intervention (12 weeks, 36 sessions) or usual care. After the intervention and a repeated assessment, all participants will cross over. Follow-up assessments will be administered at 6 and 12 months after the MedBIKE intervention. We anticipate that the MedBIKE intervention will be feasible and safely yield sustained improvements in exercise capacity, PA, HRQoL, and self-efficacy towards PA in paediatric HTRs. This study will serve as the foundation for a larger, multicentre randomized crossover trial and will help inform exercise rehabilitation programmes for paediatric HTRs.

Utility of Cardiac Rehabilitation for Long-Term Outcomes in Patients with Hospital-Acquired Functional Decline after Cardiac Surgery: A Retrospective Study

Hospital-acquired functional decline is an important outcome that affects the long-term prognosis of patients after cardiac surgery. Phase II cardiac rehabilitation (CR) for outpatients is expected to improve prognosis; however, this is not clear in patients with hospital-acquired functional decline after cardiac surgery. Therefore, this study evaluated whether phase II CR improved the long-term prognosis of patients with hospital-acquired functional decline after cardiac surgery. This single-center, retrospective observational study included 2371 patients who required cardiac surgery. Hospital-acquired functional decline occurred in 377 patients (15.9%) after cardiac surgery. The mean follow-up period was 1219 ± 682 days in all patients, and there were 221 (9.3%) cases with major adverse cardiovascular events (MACE) after discharge during the follow-up period. The Kaplan-Meier survival curves indicated that hospital-acquired functional decline and non-phase II CR was associated with a higher incidence of MACE than other groups (log-rank, p < 0.001), additionally exhibiting prognosticating MACE in multivariate Cox regression analysis (HR, 1.59; 95% CI, 1.01-2.50; p = 0.047). Hospital-acquired functional decline after cardiac surgery and non-phase II CR were risk factors for MACE. The participation in phase II CR in patients with hospital-acquired functional decline after cardiac surgery could reduce the risk of MACE.

Effectiveness of Exercise-Based Cardiac Rehabilitation for Heart Transplant Recipients: A Systematic Review and Meta-Analysis

Background:

Heart Transplant (HTx) is the ultimate chance of life for end stage Heart Failure (HF). Exercise training has consistently shown the potential to improve functional capacity in various chronic heart diseases. Still, the evidence in HTx recipients is scarcer. This study aims to systematically review the literature to evaluate the effectiveness and safety of Exercise-based Cardiac Rehabilitation (EBCR) in HTx recipients and to identify possible moderators of success.

Methods:

We conducted a systematic review and meta-analysis of randomized controlled trials on the effect and safety of EBCR in adult HTx recipients. The primary outcome was functional capacity, measured by Peak Oxygen Uptake (pVO2). We searched CENTRAL, MEDLINE, Embase, Scopus, and Web of Knowledge databases until December 2020, reviewed references of relevant articles and contacted experts. Usual care (UC), the different dosages of exercise regimens and alternative settings were allowed as comparators. A quantitative synthesis of evidence was performed using random-effects meta-analyses.

Results:

A total of 11 studies with 404 patients were included. Nine studies comprising 306 patients compared EBCR with usual care. They showed that EBCR improved pVO2 compared to usual care (Mean Difference [MD] 3.03 mL/kg/min, 95% CI [2.28-3.77]; I² = 32%). In the subgroup analysis, including length of intervention and timing of enrollment after HTx, no significant moderator was found. Two trials, with 98 patients total, compared High Intensity Interval Training (HIIT) and Moderate Intensity Continuous Training (MICT). HIIT attained a significant edge over MICT (MD 2.23 mL/kg/min, 95% CI [1.79-2.67]; I² = 0%). No major adverse events associated with EBCR were reported.

Conclusion:

We found moderate quality evidence suggesting EBCR has a significant benefit on functional capacity improvement HTx recipients at the short-term. HIIT showed superiority when compared to MICT. Research focusing long term outcomes and standardized protocols are needed to improve evidence on EBCR effectiveness.

Heart transplant recipient 1-year outcomes during the COVID-19 pandemic

The COVID‐19 pandemic initially brought forth considerable challenges to the field of heart transplantation. To prevent the spread of the virus and protect immunocompromised recipients, our center made the following modifications to post‐transplant outpatient management: eliminating early coronary angiograms, video visits for postoperative months 7, 9, and 11, and home blood draws for immunosuppression adjustments. To assess if these changes have impacted patient outcomes, the current study examines 1‐year outcomes for patients transplanted during the pandemic. Between March and September 2020, we assessed 50 heart transplant patients transplanted during the pandemic. These patients were compared to patients who were transplanted during the same months between 2011 and 2019 (n = 482). Endpoints included subsequent 1‐year survival, freedom from cardiac allograft vasculopathy, any‐treated rejection, acute cellular rejection, antibody‐mediated rejection, nonfatal major adverse cardiac events (NF‐MACE), and hospital and ICU length of stay. Patients transplanted during the pandemic had similar 1‐year endpoints compared to those of patients transplanted from years prior apart from 1‐year freedom from NF‐MACE which was significantly higher for patients transplanted during the pandemic. Despite necessary changes being made to outpatient management of heart transplant recipients, heart transplantation continues to be safe and effective with similar 1‐year outcomes to years prior.

Intensive Cardiac Rehabilitation Is Markedly Underutilized by Medicare Beneficiaries: RESULTS FROM A 2012-2016 NATIONAL SAMPLE

PURPOSE

Intensive cardiac rehabilitation (ICR) was developed to enhance traditional cardiac rehabilitation (CR) by adding sessions focused on nutrition, lifestyle behaviors, and stress management. Intensive CR has been Medicare-approved since 2010, yet little is known about national utilization rates of ICR in the Medicare population or characteristics associated with its use.

METHODS

A 5% sample of Medicare claims data from 2012 to 2016 was used to identify beneficiaries with a qualifying indication for ICR/CR and to quantify utilization of ICR or CR within 1 yr of the qualifying diagnosis.

RESULTS

From 2012 to 2015, there were 107 246 patients with a qualifying indication. Overall, only 0.1% of qualifying patients participated in ICR and 16.2% in CR from 2012 to 2016, though utilization rates of both ICR and CR increased during this period (ICR 0.06 to 0.17%, CR 14.3 to 18.2%). The number of ICR centers increased from 15 to 50 over the same period. There were no differences between ICR and CR enrollees with respect to age, sex, race, discharge location, median income, dual enrollment, or number of comorbidities. Compared with eligible beneficiaries who did not attend ICR or CR, those who attended either program were younger, more likely to be male and White, and had higher median income.

CONCLUSIONS

Although ICR and CR have a class 1 indication for the treatment of cardiovascular disease and the number of ICR centers has increased, ICR is not widely available and remains markedly underutilized. Continued research is needed to understand the barriers to program development and patient participation.

Sex Differences in Cardiac Rehabilitation Outcomes

Cardiovascular disease is a leading cause of morbidity and mortality in males and females in the United States and globally. Cardiac rehabilitation (CR) is recommended by the American Heart Association/American College of Cardiology for secondary prevention for patients with cardiovascular disease. CR participation is associated with improved cardiovascular disease risk factor management, quality of life, and exercise capacity as well as reductions in hospital admissions and mortality. Despite these advantageous clinical outcomes, significant sex disparities exist in outpatient phase II CR programming. This article reviews sex differences that are present in the spectrum of care provided by outpatient phase II CR programming (ie, from referral to clinical management). We first review CR participation by detailing the sex disparities in the rates of CR referral, enrollment, and completion. In doing so, we discuss patient, health care provider, and social/environmental level barriers to CR participation with a particular emphasis on those barriers that majorly impact females. We also evaluate sex differences in the core components incorporated into CR programming (eg, patient assessment, exercise training, hypertension management). Next, we review strategies to mitigate these sex differences in CR participation with a focus on automatic CR referral, female-only CR programming, and hybrid CR. Finally, we outline knowledge gaps and areas of future research to minimize and prevent sex differences in CR programming.

Patient selection for heart transplant: balancing risk

PURPOSE OF REVIEW

Heart failure incidence continues to rise despite a relatively static number of available donor hearts. Selecting an appropriate heart transplant candidate requires evaluation of numerous factors to balance patient benefit while maximizing the utility of scarce donor hearts. Recent research has provided new insights into refining recipient risk assessment, providing additional tools to further define and balance risk when considering heart transplantation.

RECENT FINDINGS

Recent publications have developed models to assist in risk stratifying potential heart transplant recipients based on cardiac and noncardiac factors. These studies provide additional tools to assist clinicians in balancing individual risk and benefit of heart transplantation in the context of a limited donor organ supply.

SUMMARY

The primary goal of heart transplantation is to improve survival and maximize quality of life. To meet this goal, a careful assessment of patient-specific risks is essential. The optimal approach to patient selection relies on integrating recent prognostication models with a multifactorial assessment of established clinical characteristics, comorbidities and psychosocial factors.

Inspiratory muscle weakness in cardiovascular diseases: Implications for cardiac rehabilitation

Exercise limitation is a cardinal manifestation of many cardiovascular diseases (CVD) and is associated with poor prognosis. It is increasingly well understood that exercise-based cardiac rehabilitation (CR) is an intervention that portends favorable clinical outcomes, including improvements in exercise capacity. The etiology of exercise limitation in CVD is multifactorial but is typically governed by terminal sensations of pain, fatigue, and/or breathlessness. A known but perhaps underestimated complication of CVD that contributes to breathlessness and exercise intolerance in such patients is inspiratory muscle dysfunction. For example, inspiratory muscle dysfunction, which encompasses a loss in muscle mass and/or pressure generating capacity, occurs in up to ~40% of patients with chronic heart failure and is associated with breathlessness, exertional intolerance, and worse survival in this patient population. In this review, we define inspiratory muscle weakness, detail its prevalence in a range of CVDs, and discuss how inspiratory weakness impacts physiological function and clinical outcomes in patients with CVD often referred to CR. We also evaluate the available evidence addressing the effects of exercise-based CR with and without concurrent specific inspiratory muscle training (IMT) on inspiratory muscle function, general physiological function, and clinical outcomes in patients with CVD. Finally, we consider whether the assessment of global respiratory muscle function should become standard as part of the patient intake assessment for phase II CR programs, giving practical guidance on the implementation of such measures as well as IMT as part of phase II CR.

Cardiac rehabilitation for heart transplant patients: Considerations for exercise training

Heart transplantation (HT) is the treatment of choice for eligible patients with end-stage chronic heart failure (HF). One-year survival world-wide is >85%. Many patients experience a reasonable functional ability post-HT, but episodes of acute rejection, as well as multiple co-morbidities such as hypertension, diabetes, chronic kidney disease and cardiac allograft vasculopathy are common. Immunosuppression with prednisone frequently results in increased body fat and skeletal muscle atrophy. Exercise capacity is below normal for most patients with a mean peak oxygen uptake (VO₂) of approximately 60% of expected. HT recipients have abnormal exercise physiology findings related to surgical cardiac denervation, diastolic dysfunction, and the legacy of reduced skeletal muscle oxidative capacity and impaired vasodilatory ability resulting from pre-HT chronic HF. The heart rate response to exercise is blunted. Cardiac reinnervation resulting in partial normalization of the heart rate response to exercise occurs in approximately 40% of HT recipients months to years after HT. Supervised exercise training in cardiac rehabilitation (CR) programs is safe and is recommended by professional societies both before (pre-habilitation) and after HT. Exercise training does not require alteration in immunosuppressants. Exercise training in adults after HT improves peak VO₂ and skeletal muscle strength. It has also been demonstrated to reduce the severity of cardiac allograft vasculopathy. In addition, CR exercise training is associated with reduced stroke risk, percutaneous coronary intervention, hospitalization for either acute rejection or HF, and death. There are only limited data for exercise training in the pediatric population.

Improvements in Functional Status Among Survivors of Orthotopic Heart Transplantation Following High-risk Bridging Modalities

BACKGROUND

The 2018 heart allocation change has resulted in greater frequency of high-risk bridging to orthotopic heart transplantation (OHT). Although survival has been studied in these patients, functional status outcomes are less established. This study evaluated changes in functional status of OHT survivors based on bridging strategy.

METHODS

Adults (≥18 y) undergoing OHT between January 2015 and March 2020 were stratified by bridging modality: no bridging, inotropes only, intra-aortic balloon pump (IABP), temporary ventricular assist device (VAD), durable VAD, and extracorporeal membrane oxygenation (ECMO). Using paired analysis, the Karnofsky performance scale (0-100) was utilized to compare differences in function at listing, transplant, and follow-up.

RESULTS

In total, 13 142 patients underwent OHT. At the time of both listing and transplant, patients requiring IABP, temporary VAD, and ECMO displayed the lowest functional status (each median 20) compared with other groups (P < 0.001). Among survivors, the median performance status at follow-up was ≥80 for all groups, indicating total functional independence with no assistance required. Substantial improvement in Karnofsky score occurred from transplant to follow-up in survivors bridged with IABP (40), temporary VADs (60), and ECMO (50) (each P < 0.001). Among survivors with at least 90-day follow-up, the median Karnofsky score was 90 regardless of bridging modality.

CONCLUSIONS

Despite a higher mortality risk, critically ill patients who survive OHT after bridging with high-risk modalities experience acceptable functional status outcomes. These findings are important to place in the context of the impact that the 2018 allocation change has had on the landscape of OHT in the United States.

Prognostic value of cardiopulmonary exercise test after heart transplantation

BACKGROUND

The clinical utility of cardiopulmonary exercise testing (CPET) has not been extensively studied yet in heart transplantation (HTX) patients.

OBJECTIVE

To analyze the predictive value of the CPET on hospitalizations and mortality in HTX recipients.

METHODS

A retrospective cohort was performed from a secondary database. Patients > 18 years with HTX who underwent a CPET between 3 and 12 months after transplantation were included. Time to the first primary endpoint (HTX-related hospitalization) was analyzed and adjusted using Cox proportional hazards regression model.

RESULTS

A total of 122 patients (mean age 50.1 years, 77.0% men) were included. Fifty-seven patients (46.7%) had the primary endpoint. Peak VO₂ (HR .95; CI 95% .90-.99, P = .03), oxygen pulse (HR .57; CI 95% .34-.96, P = .03) and predicted VO₂ (HR .97; CI 95% .96-.99, P = .002) were associated with the endpoint. We did not find a significant association between the other variables and the outcome.

CONCLUSION

In HTX recipients, peak VO₂ , oxygen pulse, and predicted VO₂ were independently associated with hospitalizations at follow up.

Exercise-based rehabilitation strategies in heart transplant recipients: Focus on high-intensity interval training

Despite progressive improvement in medical therapy and standard care, the exercise capacity of heart transplant recipients is reduced compared with age-matched healthy individuals. Exercise-based rehabilitation programs have been shown to improve the exercise capacity of transplant patients through a multifactorial effect. In this context, high-intensity interval exercise is a growing field of research, with current evidence suggesting a major benefit in heart transplant recipients compared with a conventional training protocol. Therefore, this study aimed to provide an overview of the mechanisms involved in the reduced exercise capacity of heart transplant patients and a review of current rehabilitation strategies with a special focus on the mechanisms and clinical effects of high-intensity interval training exercise.