Cardiac Rehabilitation Use After Heart Failure Hospitalization Associated With Advanced Heart Failure Center Status

PURPOSE

Cardiac rehabilitation (CR) is an evidence-based, guideline-endorsed therapy for patients with heart failure with reduced ejection fraction (HFrEF) but is broadly underutilized. Identifying structural factors contributing to increased CR use may inform quality improvement efforts. The objective here was to associate hospitalization at a center providing advanced heart failure (HF) therapies and subsequent CR participation among patients with HFrEF.

METHODS

A retrospective analysis was performed on a 20% sample of Medicare beneficiaries primarily hospitalized with an HFrEF diagnosis between January 2008 and December 2018. Outpatient claims were used to identify CR use (no/yes), days to first session, number of attended sessions, and completion of 36 sessions. The association between advanced HF status (hospitals performing heart transplantation or ventricular assist device implantations) and CR participation was evaluated with logistic regression, accounting for patient, hospital, and regional factors.

RESULTS

Among 143 392 Medicare beneficiaries, 29 487 (20.6%) were admitted to advanced HF centers (HFCs) and 5317 (3.7%) attended a single CR session within 1 yr of discharge. In multivariable analysis, advanced HFC status was associated with significantly greater relative odds of participating in CR (OR = 2.20: 95% CI, 2.08-2.33; P < .001) and earlier initiation of CR participation (-8.5 d; 95% CI, -12.6 to 4.4; P < .001). Advanced HFC status had little to no association with the intensity of CR participation (number of visits or 36 visit completion).

CONCLUSIONS

Medicare beneficiaries hospitalized for HF were more likely to attend CR after discharge if admitted to an advanced HFC than a nonadvanced HFC.

The iATTEND Trial: A Trial Comparing Hybrid Versus Standard Cardiac Rehabilitation

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.

Interhospital Variability in Cardiac Rehabilitation Use After Cardiac Surgery Among Medicare Beneficiaries

OBJECTIVE

Despite guideline recommendation, cardiac rehabilitation (CR) following cardiac surgery remains underutilized, and the extent of interhospital variability is not well understood. This study evaluated determinants of interhospital variability in CR use and outcomes.

METHODS

This retrospective cohort study included 166,809 Medicare beneficiaries undergoing cardiac surgery who were discharged alive between 07/01/2016 and 12/31/2018. CR participation was identified in outpatient facility claims within a year of discharge. Hospital-level CR rates were tabulated, and multilevel models evaluated the extent to which patient, organizational, and regional factors accounted for interhospital variability. Adjusted 1-year mortality and readmission rates were also calculated for each hospital quartile of CR use.

RESULTS

Overall, 90,171 (54.1%) participated in at least one CR session within a year of discharge. Interhospital CR rates ranged from 0.0% to 96.8%. Hospital factors that predicted CR use included non-teaching status and lower hospital volume. Before adjusting for patient, organizational, and regional factors, 19.3% of interhospital variability was attributable to the admitting hospital. After accounting for covariates, 12.3% of variation was attributable to the admitting hospital. Patient (0.5%), structural (2.8%), and regional (3.7%) factors accounted for the remaining explained variation. Hospitals in the lowest quartile of CR use had higher adjusted 1-year mortality rates (Q1 = 6.7%, Q4 = 5.2%, p < 0.001) and readmission rates (Q1 = 37.6%, Q4 = 33.9%, p<0.001).

CONCLUSION

Identifying best practices among high CR use facilities and barriers to access in low CR use hospitals may reduce interhospital variability in CR use and advance national improvement efforts.

FIT calculator: a multi-risk prediction framework for medical outcomes using cardiorespiratory fitness data

Accurately predicting patients' risk for specific medical outcomes is paramount for effective healthcare management and personalized medicine. While a substantial body of literature addresses the prediction of diverse medical conditions, existing models predominantly focus on singular outcomes, limiting their scope to one disease at a time. However, clinical reality often entails patients concurrently facing multiple health risks across various medical domains. In response to this gap, our study proposes a novel multi-risk framework adept at simultaneous risk prediction for multiple clinical outcomes, including diabetes, mortality, and hypertension. Leveraging a concise set of features extracted from patients' cardiorespiratory fitness data, our framework minimizes computational complexity while maximizing predictive accuracy. Moreover, we integrate a state-of-the-art instance-based interpretability technique into our framework, providing users with comprehensive explanations for each prediction. These explanations afford medical practitioners invaluable insights into the primary health factors influencing individual predictions, fostering greater trust and utility in the underlying prediction models. Our approach thus stands to significantly enhance healthcare decision-making processes, facilitating more targeted interventions and improving patient outcomes in clinical practice. Our prediction framework utilizes an automated machine learning framework, Auto-Weka, to optimize machine learning models and hyper-parameter configurations for the simultaneous prediction of three medical outcomes: diabetes, mortality, and hypertension. Additionally, we employ a local interpretability technique to elucidate predictions generated by our framework. These explanations manifest visually, highlighting key attributes contributing to each instance's prediction for enhanced interpretability. Using automated machine learning techniques, the models simultaneously predict hypertension, mortality, and diabetes risks, utilizing only nine patient features. They achieved an average AUC of 0.90 ± 0.001 on the hypertension dataset, 0.90 ± 0.002 on the mortality dataset, and 0.89 ± 0.001 on the diabetes dataset through tenfold cross-validation. Additionally, the models demonstrated strong performance with an average AUC of 0.89 ± 0.001 on the hypertension dataset, 0.90 ± 0.001 on the mortality dataset, and 0.89 ± 0.001 on the diabetes dataset using bootstrap evaluation with 1000 resamples.

The relationship between discharge location and cardiac rehabilitation use after cardiac surgery

BACKGROUND

Cardiac rehabilitation (CR) is a guideline-recommended risk-reduction program offered to cardiac surgical patients. Despite CR's association with better outcomes, attendance remains poor. The relationship between discharge location and CR use is poorly understood.

METHODS

This study was a nationwide, retrospective cohort analysis of Medicare fee-for-service claims for beneficiaries undergoing coronary artery bypass grafting and/or surgical aortic valve repair between July 1, 2016, and December 31, 2018. The primary outcome was attendance of any CR session. Discharge location was categorized as home discharge or discharge to extended care facility (ECF) (including skilled nursing facility, inpatient rehabilitation, and long-term acute care). Multivariable logistic regression models evaluated the association between discharge location, CR attendance, and 1-year mortality.

RESULTS

Of the 167,966 patients who met inclusion criteria, 34.1% discharged to an ECF. Overall CR usage rate was 53.9%. Unadjusted and adjusted CR use was lower among patients discharged ECFs versus those discharged home (42.1% vs 60.0%; adjusted odds ratio, 0.66; P < .001). Patients discharged to long-term acute care were less likely to use CR than those discharged to skilled nursing facility or inpatient rehabilitation (reference category: home; adjusted odds ratio for long-term acute care, 0.36, adjusted odds ratio for skilled nursing facility, 0.69, and adjusted odds ratio for inpatient rehabilitation, 0.71; P < .001). CR attendance was associated with a greater reduction in adjusted 1-year mortality in patients discharged to ECFs (9.7% reduction) versus those discharged home (4.3% reduction).

CONCLUSIONS

In this national analysis of Medicare beneficiaries, discharge to ECF was associated with lower CR use, despite a greater association with improved 1-year mortality. Interventions aimed at increasing CR enrollment at ECFs may improve CR use and advance surgical quality.

Among Patients Taking Beta-Adrenergic Blockade Therapy, Use Measured (Not Predicted) Maximal Heart Rate to Calculate a Target Heart Rate for Cardiac Rehabilitation

PURPOSE

Among patients in cardiac rehabilitation (CR) on beta-adrenergic blockade (βB) therapy, this study describes the frequency for which target heart rate (THR) values computed using a predicted maximal heart rate (HR max ), correspond to a THR computed using a measured HR max in the guideline-based heart rate reserve (HR reserve ) method.

METHODS

Before CR, patients completed a cardiopulmonary exercise test to measure HR max , with the data used to determine THR via the HR reserve method. Additionally, predicted HR max was computed for all patients using the 220 - age equation and two disease-specific equations, with the predicted values used to calculate THR via the straight percent and HR reserve methods. The THR was also computed using resting heart rate (HR) +20 and +30 bpm.

RESULTS

Mean predicted HR max using the 220 - age equation (161 ± 11 bpm) and the disease-specific equations (123 ± 9 bpm) differed ( P < .001) from measured HR max (133 ± 21 bpm). Also, THR computed using predicted HR max resulted in values that were infrequently within the guideline-based HR reserve range calculated using measured HR max . Specifically, 0 to ≤61% of patients would have had an exercise training HR that fell within the guideline-based range of 50-80% of measured HR reserve . Use of standing resting HR +20 or +30 bpm would have resulted in 100% and 48%, respectively, of patients exercising below 50% of HR reserve .

CONCLUSIONS

A THR computed using either predicted HR max or resting HR +20 or +30 bpm seldom results in a prescribed exercise intensity that is consistent with guideline recommendations for patients in CR.

Cardiac Rehabilitation Reduces 2-Year Mortality After Coronary Artery Bypass Grafting

BACKGROUND

Cardiac rehabilitation (CR) is a supervised outpatient exercise and risk reduction program offered to patients who have undergone coronary revascularization procedures. Multiple professional societal guidelines support the use of CR after coronary artery bypass grafting (CABG) based on studies in combined percutaneous coronary intervention and CABG populations with surrogate outcomes. This statewide analysis of patients undergoing CABG evaluated the relationship between CR use and long-term mortality.

METHODS

Medicare fee-for-service claims were linked to surgical data for patients discharged alive after isolated CABG from January 1, 2015, through September 30, 2019. Outpatient facility claims were used to identify any CR use within 1 year of discharge. Death within 2 years of discharge was the primary outcome. Mixed-effects logistic regression was used to predict CR use, adjusting for a variety of comorbidities. Unadjusted and inverse probability treatment weighting (IPTW) were used to compare 2-year mortality among CR users vs nonusers.

RESULTS

A total of 3848 of 6412 patients (60.0%) were enrolled in CR for an average of 23.2 (SD, 12.0) sessions, with 770 of 6412 (12.0%) completing all recommended 36 sessions. Logistic regression identified increasing age, discharge to home (vs extended care facility), and shorter length of stay as predictors of postdischarge CR use (P < .05). Unadjusted and IPTW analyses showed significant reduction in 2-year mortality in CR users compared with CR nonusers (unadjusted: 9.4% reduction; 95% CI, 10.8%-7.9%; P < .001; IPTW: -4.8% reduction; 95% CI, 6.0%-3.5%; P < .001).

CONCLUSIONS

These data suggest that CR use is associated with lower 2-year mortality. Future quality initiatives should consider identifying and addressing root causes of poor CR enrollment and completion.

Relationship Between Community-Level Distress and Cardiac Rehabilitation Participation, Facility Access, and Clinical Outcomes After Inpatient Coronary Revascularization

BACKGROUND

Although disparities in cardiac rehabilitation (CR) participation are well documented, the role of community-level distress is poorly understood. This study evaluated the relationship between community-level distress and CR participation, access to CR facilities, and clinical outcomes.

METHODS

A retrospective cohort study was conducted on a 100% sample of Medicare beneficiaries undergoing inpatient coronary revascularization between July 2016 and December 2018. Community-level distress was defined using the Distressed Community Index quintile at the beneficiary zip code level, with the first and fifth quintiles representing prosperous and distressed communities, respectively. Outpatient claims were used to identify any CR use within 1 year of discharge. Beneficiary and CR facility zip codes were used to describe access to CR facilities. Adjusted logistic regression models evaluated the association between Distressed Community Index quintiles, CR use, and clinical outcomes, including one-year mortality, all-cause hospitalization, and acute myocardial infarction hospitalization.

RESULTS

A total of 414 730 beneficiaries were identified, with 96 929 (23.4%) located in the first and 67 900 (16.4%) in the fifth quintiles, respectively. Any CR use was lower for beneficiaries in distressed compared with prosperous communities (26.0% versus 46.1%, P<0.001), which was significant after multivariable adjustment (odds ratio, 0.41 [95% CI, 0.40-0.42]). A total of 98 458 (23.7%) beneficiaries had a CR facility within their zip code, which increased from 16.3% in prosperous communities to 26.6% in distressed communities. Any CR use was associated with absolute reductions in mortality (-6.8% [95% CI, -7.0% to -6.7%]), all-cause hospitalization (-5.9% [95% CI, -6.3% to -5.6%]), and acute myocardial infarction hospitalization (-1.3% [95% CI, -1.5% to -1.1%]), which were similar across each Distressed Community Index quintiles.

CONCLUSIONS

Although community-level distress was associated with lower CR participation, the clinical benefits were universally received. Addressing barriers to CR in distressed communities should be considered a significant priority to improve survival after coronary revascularization and reduce disparities.

Improved cardiorespiratory fitness is associated with lower incident ischemic stroke risk: Henry Ford FIT project

BACKGROUND

Change in cardiorespiratory fitness (CRF) modulates vascular disease risk; however, it's unclear if this adds further prognostic information, particularly for ischemic stroke. The objective of this analysis is to describe the association between the change in CRF over time and subsequent incident ischemic stroke.

METHODS

This is a retrospective, longitudinal, observational cohort study of 9,646 patients (age=55±11 years; 41% women; 25% black) who completed 2 clinically indicated exercise tests (> 12 months apart) and were free of any stroke at the time of test 2. CRF was expressed as metabolic-equivalents-of-task (METs). Incident ischemic stroke was identified using ICD codes. The adjusted hazard ratio (aHR) was determined for risk of ischemic stroke associated with change in CRF.

RESULTS

Mean time between tests was 3.7 years (IQR, 2.2, 6.0). During a median of 5.0 years (IQR, 2.7, 7.6 y) of follow-up, there were 873 (9.1%) ischemic stroke events. Each 1 MET increase between tests was associated with a 9% lower ischemic stroke risk (aHR 0.91 [0.88-0.94]; n = 9.646). There was an interaction effect by baseline CRF category, but not for sex or race. A sensitivity analysis which removed those who experienced an incident diagnosis known to be associated with an increased risk of ischemic vascular disease, validated our primary findings (aHR 0.91 [0.88, 0.95]; n= 6,943).

CONCLUSIONS

Improvement in CRF over time is independently and inversely associated with a lower risk of ischemic stroke. Encouragement of regular exercise focused on improving CRF may reduce ischemic stroke risk.

Comorbidities are associated with state hopelessness in adults with ischemic heart disease

BACKGROUND

In adults with ischemic heart disease (IHD), comorbidities and hopelessness are independently associated with increased risk of mortality.

OBJECTIVES

To determine if comorbidities were associated with state and trait hopelessness and explore the influence of specific conditions and hopelessness in individuals hospitalized for IHD.

METHODS

Participants completed the State-Trait Hopelessness Scale. Charlson Comorbidity Index (CCI) scores were generated from the medical record. A chi-squared test was used to examine differences in 14 diagnoses included in the CCI by CCI severity. Unadjusted and adjusted linear models were used to explore the relationship between hopelessness levels and the CCI.

RESULTS

Participants (n=132) were predominantly male (68.9%), with a mean age of 62.6 years, and majority white (97%). The mean CCI was 3.5 (range 0-14), with 36.4% having a score of 1-2 (mild), 41.2% with a score of 3-4 (moderate) and 22.7% with a score of ≥5 (severe). The CCI was positively associated with both state (β=0.03; 95% CI 0.01, 0.05; p=0.002) and trait (β=0.04; 95% CI 0.01, 0.06; p=0.007) hopelessness in unadjusted models. The relationship for state hopelessness remained significant after adjusting for multiple demographic characteristics (β=0.03; 95% CI 0.01, 0.05; p=0.02), while trait hopelessness did not. Interaction terms were evaluated, and findings did not differ by age, sex, education level, or diagnosis/type of intervention.

CONCLUSION

Hospitalized individuals with IHD with a higher number of comorbidities may benefit from targeted assessment and brief cognitive intervention to identify and ameliorate state hopelessness which has been associated with worse long-term outcomes.

Supervised Exercise Training for Chronic Heart Failure With Preserved Ejection Fraction: A Scientific Statement From the American Heart Association and American College of Cardiology

Heart failure with preserved ejection fraction (HFpEF) is one of the most common forms of heart failure; its prevalence is increasing, and outcomes are worsening. Affected patients often experience severe exertional dyspnea and debilitating fatigue, as well as poor quality of life, frequent hospitalizations, and a high mortality rate. Until recently, most pharmacological intervention trials for HFpEF yielded neutral primary outcomes. In contrast, trials of exercise-based interventions have consistently demonstrated large, significant, clinically meaningful improvements in symptoms, objectively determined exercise capacity, and usually quality of life. This success may be attributed, at least in part, to the pleiotropic effects of exercise, which may favorably affect the full range of abnormalities-peripheral vascular, skeletal muscle, and cardiovascular-that contribute to exercise intolerance in HFpEF. Accordingly, this scientific statement critically examines the currently available literature on the effects of exercise-based therapies for chronic stable HFpEF, potential mechanisms for improvement of exercise capacity and symptoms, and how these data compare with exercise therapy for other cardiovascular conditions. Specifically, data reviewed herein demonstrate a comparable or larger magnitude of improvement in exercise capacity from supervised exercise training in patients with chronic HFpEF compared with those with heart failure with reduced ejection fraction, although Medicare reimbursement is available only for the latter group. Finally, critical gaps in implementation of exercise-based therapies for patients with HFpEF, including exercise setting, training modalities, combinations with other strategies such as diet and medications, long-term adherence, incorporation of innovative and more accessible delivery methods, and management of recently hospitalized patients are highlighted to provide guidance for future research.

Supervised Exercise Training for Chronic Heart Failure With Preserved Ejection Fraction: A Scientific Statement From the American Heart Association and American College of Cardiology

Heart failure with preserved ejection fraction (HFpEF) is one of the most common forms of heart failure; its prevalence is increasing, and outcomes are worsening. Affected patients often experience severe exertional dyspnea and debilitating fatigue, as well as poor quality of life, frequent hospitalizations, and a high mortality rate. Until recently, most pharmacological intervention trials for HFpEF yielded neutral primary outcomes. In contrast, trials of exercise-based interventions have consistently demonstrated large, significant, clinically meaningful improvements in symptoms, objectively determined exercise capacity, and usually quality of life. This success may be attributed, at least in part, to the pleiotropic effects of exercise, which may favorably affect the full range of abnormalities-peripheral vascular, skeletal muscle, and cardiovascular-that contribute to exercise intolerance in HFpEF. Accordingly, this scientific statement critically examines the currently available literature on the effects of exercise-based therapies for chronic stable HFpEF, potential mechanisms for improvement of exercise capacity and symptoms, and how these data compare with exercise therapy for other cardiovascular conditions. Specifically, data reviewed herein demonstrate a comparable or larger magnitude of improvement in exercise capacity from supervised exercise training in patients with chronic HFpEF compared with those with heart failure with reduced ejection fraction, although Medicare reimbursement is available only for the latter group. Finally, critical gaps in implementation of exercise-based therapies for patients with HFpEF, including exercise setting, training modalities, combinations with other strategies such as diet and medications, long-term adherence, incorporation of innovative and more accessible delivery methods, and management of recently hospitalized patients are highlighted to provide guidance for future research.

Cardiac Rehabilitation Improves Fitness in Patients With Subclinical Markers of Cardiotoxicity While Receiving Chemotherapy: A RANDOMIZED CONTROLLED STUDY

PURPOSE

Heart failure (HF) due to cardiotoxicity is a leading non-cancer-related cause of morbidity and mortality in cancer survivors. Cardiac rehabilitation (CR) improves cardiorespiratory fitness (CRF) and reduces morbidity and mortality in patients with HF, but little is known about its effects on cardiotoxicity in the cancer population. The objective of this study was to determine whether participation in CR improves CRF in patients undergoing treatment with either doxorubicin or trastuzumab who exhibit markers of subclinical cardiotoxicity.

METHODS

Female patients with cancer (n = 28: breast, n = 1: leiomyosarcoma) and evidence of subclinical cardiotoxicity (ie, >10% relative decrease in global longitudinal strain or a cardiac troponin of >40 ng·L -1 ) were randomized to 10 wk of CR or usual care. Exercise consisted of 3 d/wk of interval training at 60-90% of heart rate reserve.

RESULTS

Cardiorespiratory fitness, as measured by peak oxygen uptake (V˙ o2peak ), improved in the CR group (16.9 + 5.0 to 18.5 + 6.0 mL∙kg -1 ∙min -1 ) while it decreased in the usual care group (17.9 + 3.9 to 16.9 + 4.0 mL∙kg -1 ∙min -1 ) ( P = .009). No changes were observed between groups with respect to high-sensitivity troponin or global longitudinal strain.

CONCLUSION

This study suggests that the use of CR may be a viable option to attenuate the reduction in CRF that occurs in patients undergoing cardiotoxic chemotherapy. The long-term effects of exercise on chemotherapy-induced HF warrant further investigation.

Evaluating the Feasibility of a Statewide Collaboration to Improve Cardiac Rehabilitation Participation: THE MICHIGAN CARDIAC REHAB NETWORK

PURPOSE

Regional quality improvement collaboratives may provide one solution to improving cardiac rehabilitation (CR) participation through performance benchmarking and provider engagement. The objective of this study was to evaluate the feasibility of the Michigan Cardiac Rehab Network to improve CR participation.

METHODS

Multipayer claims data from the Michigan Value Collaborative were used to identify hospitals and CR facilities and assemble a multidisciplinary advisory group. Univariate analyses described participating hospital characteristics and hospital-level rates of CR performance across eligible conditions including enrollment within 1 yr, mean days to first CR visit, and mean number of CR visits within 1 yr. Three diverse CR facilities were chosen for virtual site visits to identify areas of success and barriers to improvement.

RESULTS

A total of 95 hospitals and 84 CR facilities were identified, with 48 hospitals (51%) providing interventional cardiology services and 33 (35%) providing cardiac surgical services. A 17-member multidisciplinary advisory group was assembled representing 13 institutions and diverse roles. Statewide CR enrollment across eligible admissions was 33.4%, with wide variation in CR performance measures across participating hospitals and eligible admissions. Virtual site visits revealed individual successes in improving CR participation but a variety of barriers to participation related to referrals, capacity and staffing constraints, and geographic and financial barriers.

CONCLUSIONS

This study demonstrated the feasibility of creating a statewide collaboration of hospitals and CR facilities centered around the goal of equitably improving CR enrollment for all eligible patients in Michigan that is supported by a multidisciplinary advisory group and performance benchmarking.

Cardiac Rehabilitation and the COVID-19 Pandemic: Persistent Declines in Cardiac Rehabilitation Participation and Access Among US Medicare Beneficiaries

BACKGROUND

The impact of the COVID-19 pandemic on participation in and availability of cardiac rehabilitation (CR) is unknown.

METHODS

Among eligible Medicare fee-for-service beneficiaries, we evaluated, by month, the number of CR sessions attended per 100 000 beneficiaries, individuals eligible to initiate CR, and centers offering in-person CR between January 2019 and December 2021. We compared these outcomes between 2 periods: December 1, 2019 through February 28, 2020 (period 1, before declaration of the pandemic-related national emergency) and October 1, 2021 through December 31, 2021 (period 2, the latest period for which data are currently available).

RESULTS

In period 1, Medicare beneficiaries participated in (mean±SD) 895±84 CR sessions per 100 000 beneficiaries each month. After the national emergency was declared, CR participation sharply declined to 56 CR sessions per 100 000 beneficiaries in April 2020. CR participation recovered gradually through December 2021 but remained lower than prepandemic levels (period 2: 698±29 CR sessions per month per 100 000 beneficiaries, P=0.02). Declines in CR participation were most marked among dual Medicare and Medicaid enrollees and patients residing in rural areas or socially vulnerable communities. There was no statistically significant change in CR eligibility between the 2 periods. Compared with 2618±5 CR centers in period 1, there were 2464±7 in period 2 (P<0.01). Compared with CR centers that survived the pandemic, 220 CR centers that closed were more likely to be affiliated with public hospitals, located in rural areas, and serve the most socially vulnerable communities.

CONCLUSIONS

The COVID-19 pandemic was associated with a persistent decline in CR participation and the closure of CR centers, which disproportionately affected rural and low-income patients and the most socially vulnerable communities. Innovation in CR financing and delivery is urgently needed to equitably enhance CR participation among Medicare beneficiaries.

Exercise Prescription Methods and Attitudes in Cardiac Rehabilitation: A NATIONAL SURVEY

PURPOSE

High-quality exercise training improves outcomes in cardiac rehabilitation (CR), but little is known about how most programs prescribe exercise. Thus, the aim was to describe how current CR programs prescribe exercise.

METHODS

We conducted a 33-item anonymous survey of CR program directors registered with the American Association of Cardiovascular and Pulmonary Rehabilitation. We assessed the time, mode, and intensity of exercise prescribed, as well as attitudes about maximal exercise testing and exercise prescription. Results were summarized using descriptive statistics. Open-ended responses were coded and quantitated thematically.

RESULTS

Of 1470 program directors, 246 (16.7%) completed the survey. In a typical session of CR, a median of 5, 35, 10, and 5 min was spent on warm-up, aerobic exercise, resistance training, and cooldown, respectively. The primary aerobic modality was the treadmill (55%) or seated dual-action step machine (40%). Maximal exercise testing and high-intensity interval training (HIIT) were infrequently reported (17 and 8% of patients, respectively). The most common method to prescribe exercise intensity was ratings of perceived exertion followed by resting heart rate +20-30 bpm, although 55 unique formulas for establishing a target heart rate or range (THRR) were reported. Moreover, variation in exercise prescription between staff members in the same program was reported in 40% of programs. Program directors reported both strongly favorable and unfavorable opinions toward maximal exercise testing, HIIT, and use of THRR.

CONCLUSIONS

Cardiac rehabilitation program directors reported generally consistent exercise time and modes, but widely divergent methods and opinions toward prescribing exercise intensity. Our results suggest a need to better study and standardize exercise intensity in CR.

Heart Failure in Cardiac Rehabilitation: A REVIEW AND PRACTICAL CONSIDERATIONS

PURPOSE

Exercise cardiac rehabilitation (CR) represents an evidence-based therapy for patients with heart failure with reduced ejection fraction (HFrEF) and this article provides a concise review of the relevant exercise testing and CR literature, including aspects unique to their care.

CLINICAL CONSIDERATIONS

A hallmark feature of HFrEF is exercise intolerance (eg, early-onset fatigue). Drug therapies for HFrEF target neurohormonal pathways to blunt negative remodeling of the cardiac architecture and restore favorable loading conditions. Guideline drug therapy includes β-adrenergic blocking agents; blockade of the renin-angiotensin system; aldosterone antagonism; sodium-glucose cotransport inhibition; and diuretics, as needed.

EXERCISE TESTING AND TRAINING

Various assessments are used to quantify exercise capacity in patients with HFrEF, including peak oxygen uptake measured during an exercise test and 6-min walk distance. The mechanisms responsible for the exercise intolerance include abnormalities in ( a ) central transport (chronotropic response, stroke volume) and ( b ) the diffusion/utilization of oxygen in skeletal muscles. Cardiac rehabilitation improves exercise capacity, intermediate physiologic measures (eg, endothelial function and sympathetic nervous system activity), health-related quality of life (HRQoL), and likely clinical outcomes. The prescription of exercise in patients with HFrEF is generally similar to that for other patients with cardiovascular disease; however, patients having undergone an advanced surgical therapy do present with features that require attention.

SUMMARY

Few patients with HFrEF enroll in CR and as such, many miss the derived benefits, including improved exercise capacity, a likely reduction in risk for subsequent clinical events (eg, rehospitalization), improved HRQoL, and adoption of disease management strategies.

Relation of a Maximal Exercise Test to Change in Exercise Tolerance During Cardiac Rehabilitation

The purpose of this study was to test the hypothesis that an individualized exercise training target heart rate (HR) based on a maximal graded exercise test (GXT) is associated with greater improvements in exercise tolerance during cardiac rehabilitation (CR) compared with no GXT. In this retrospective study, we identified patients who completed 9 to 36 visits of CR between 2001 and 2016, with a length of stay ≤18 weeks and a visit frequency of 1 to 3 days per week. Patients were grouped based on whether their exercise was guided by a target HR determined from a GXT. To assess the relation between GXT and change in exercise training metabolic equivalents of task (METs), we used generalized linear models adjusted for age, gender, race, referral reason, CR visits, CR frequency, METs at start, CR location, and year of participation. Out of 4,455 patients (37% female, 48% White, median age = 62 years), 53% were prescribed a target HR based on a GXT. Compared with no GXT, a GXT was associated with a significantly greater increase in covariate-adjusted METs during CR and percentage change from start (+0.44 METs [95% confidence interval [CI] 0.38 to 0.51] and +17% [95% CI 14% to 19%], respectively). In a sensitivity analysis limited to patients with 24 to 36 visits at ≥2 days per week (n = 1,319), a GXT was associated with a significantly greater increase in covariate-adjusted exercise training METs (+0.51 [95% CI 0.36 to 0.66]; +19% [95% CI 13% to 24%]). In conclusion, to maximize the potential increase in exercise capacity during CR, patients should undergo a GXT to determine an individualized exercise training target HR.

Tracking Cardiac Rehabilitation Utilization in Medicare Beneficiaries: 2017 UPDATE

PURPOSE

This study updates cardiac rehabilitation (CR) utilization data in a cohort of Medicare beneficiaries hospitalized for CR-eligible events in 2017, including stratification by select patient demographics and state of residence.

METHODS

We identified Medicare fee-for-service beneficiaries who experienced a CR-eligible event and assessed their CR participation (≥1 CR sessions in 365 d), engagement, and completion (≥36 sessions) rates through September 7, 2019. Measures were assessed overall, by beneficiary characteristics and state of residence, and by primary (myocardial infarction; coronary artery bypass surgery; heart valve repair/replacement; percutaneous coronary intervention; or heart/heart-lung transplant) and secondary (angina; heart failure) qualifying event type.

RESULTS

In 2017, 412 080 Medicare beneficiaries had a primary CR-eligible event and 28.6% completed ≥1 session of CR within 365 d after discharge from a qualifying event. Among beneficiaries who completed ≥1 CR session, the mean total number of sessions was 25 ± 12 and 27.6% completed ≥36 sessions. Nebraska had the highest enrollment rate (56.1%), with four other states also achieving an enrollment rate >50% and 23 states falling below the overall rate for the United States.

CONCLUSIONS

The absolute enrollment, engagement, and program completion rates remain low among Medicare beneficiaries, indicating that many patients did not benefit or fully benefit from a class I guideline-recommended therapy. Additional research and continued widespread adoption of successful enrollment and engagement initiatives are needed, especially among identified populations.

Variation in Cardiac Rehabilitation Participation During Aortic Valve Replacement Episodes of Care

BACKGROUND

Despite reported benefit in the setting of aortic valve replacement (AVR), cardiac rehabilitation (CR) utilization remains low, with few studies evaluating hospital and patient-level variation in CR participation. We explored determinants of CR variability during AVR episodes of care: transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR).

METHODS

A cohort of 10 124 AVR episodes of care (TAVR n=5121 from 24 hospitals; SAVR n=5003 from 32 hospitals) were identified from the Michigan Value Collaborative statewide multipayer registry (2015-2019). CR enrollment was defined as the presence of a single professional or facility claim within 90 days of discharge: 93 797, 93 798, G0422, G0423. Annual trends and hospital variation in CR were described for TAVR, SAVR, and all AVR. Multilevel logistic regression was used to estimate effects of predictors and hospital risk-adjusted rates of CR enrollment.

RESULTS

Overall, 4027 (39.8%) patients enrolled in CR, with significant differences by treatment strategy: SAVR=50.9%, TAVR=28.9% (P<0.001). CR use after SAVR was significantly higher than after TAVR and increased over time for both modalities (P<0.001). There were significant differences in CR enrollment across age, gender, payer, and some comorbidities (P<0.05). At the hospital level, CR participation rates for all AVR varied 10-fold (4.8% to 68.7%) and were moderately correlated between SAVR and TAVR (Pearson r=0.56, P<0.01).

CONCLUSIONS

Substantial variation exists in CR participation during AVR episodes of care across hospitals. However, within-hospital CR participation rates were significantly correlated across treatment strategies. These findings suggest that CR participation is the product of hospital-specific practice patterns. Identifying hospital practices associated with higher CR participation can help assist future quality improvement efforts to increase CR use after AVR.

Abstract 49: Variation In Cardiac Rehabilitation Enrollment During Aortic Valve Replacement Episodes Of Care

Intro: Despite providing benefit in the setting of aortic valve replacement (AVR), cardiac rehabilitation (CR) utilization remains low, with few studies evaluating hospital and patient-level variation in CR enrollment. We explored determinants of CR variability during AVR episodes of care: transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR).

Methods/Results: A cohort of 10,124 AVR episodes of care (TAVR n=5,121 from 24 hospitals; SAVR n=5,003 from 32 hospitals) were identified from the Michigan Value Collaborative statewide multipayer registry (2015 to 2019). CR enrollment was defined as the presence of a professional or facility claim (93797, 93798, G0422, G0423) within 90 days of discharge. Annual trends in CR were evaluated for TAVR, SAVR, and all AVR. CR use in SAVR was significantly higher than TAVR and increased over time for all modalities (p<0.001, Figure 1). Multilevel logistic regression analysis identified significant differences in CR enrollment across age groups, comorbidities, and payer status. At the hospital-level, CR enrollment rates for all AVR varied 10-fold (4.8% to 68.7%) and moderately correlated between SAVR and TAVR (Pearson r=0.56, p<0.01, Figure 2).

Conclusions: Substantial variation exists in CR enrollment during AVR episodes of care across hospitals. However, within-hospital CR enrollment rates were significantly correlated across treatment strategies. These findings suggest that CR enrollment is the product of hospital-specific practice patterns. Identifying hospital practices associated with higher CR enrollment can help assist future quality improvement efforts to increase CR use after AVR.

Abstract 29: Evaluating The Feasibility Of A Statewide Collaboration To Improve Cardiac Rehabilitation Participation: The Michigan Cardiac Rehabilitation Consortium

Background: Regional quality improvement collaboratives may provide one solution to improving cardiac rehabilitation (CR) participation through performance benchmarking and provider engagement. The objective of this descriptive study was to evaluate the feasibility of the Michigan Cardiac Rehab Consortium to improve CR participation

Methods and Results: Multipayer claims data from the Michigan Value Collaborative were used to identify hospitals and CR facilities. Univariate analyses described participating hospital characteristics and hospital-level rates of CR enrollment within 1-year. A total of 95 hospitals and 85 CR facilities with 48 hospitals (51%) providing interventional cardiology services and 33 (35%) provided cardiac surgical services. The overall consortium-wide enrollment rate into CR across all conditions was 19.8% (26,398 of 133,641 eligible admissions), which was highest for CABG (58.4%), followed by SAVR (54.8%), PCI (34.6%), TAVR (33.1%), AMI (12.7%), and CHF (3.4%). There was wide variation in CR participation across participating eligible admissions and hospitals (Figure). A 17-member multidisciplinary stakeholder group was assembled representing 12 institutions and diverse roles, including exercise physiologists, cardiologist, program directors, and patients. Three diverse CR facilities participated in virtual site visits, which revealed individual successes in improving CR participation, but a variety of barriers to participation related to referrals, capacity and staffing constraints, and geographic and financial barriers.

Conclusions: This study demonstrated the feasibility of a statewide collaboration centered around the goal of equitably improving CR enrollment for all eligible patients that is supported by a multidisciplinary stakeholder group and performance benchmarking. Future work will seek to continuously improve and evaluate the impact of this consortium on CR participation in Michigan.

The HEART Camp Exercise Intervention Improves Exercise Adherence, Physical Function, and Patient-Reported Outcomes in Adults With Preserved Ejection Fraction Heart Failure

BACKGROUND

Despite exercise being one of few strategies to improve outcomes for individuals with heart failure with preserved ejection fraction (HFpEF), exercise clinical trials in HFpEF are plagued by poor interventional adherence. Over the last 2 decades, our research team has developed, tested, and refined Heart failure Exercise And Resistance Training (HEART) Camp, a multicomponent behavioral intervention to promote adherence to exercise in HF. We evaluated the effects of this intervention designed to promote adherence to exercise in HF focusing on subgroups of participants with HFpEF and heart failure with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

This randomized controlled trial included 204 adults with stable, chronic HF. Of those enrolled, 59 had HFpEF and 145 had HFrEF. We tested adherence to exercise (defined as ≥120 minutes of moderate-intensity [40%-80% of heart rate reserve] exercise per week validated with a heart rate monitor) at 6, 12, and 18 months. We also tested intervention effects on symptoms (Patient-Reported Outcomes Measurement Information System-29 and dyspnea-fatigue index), HF-related health status (Kansas City Cardiomyopathy Questionnaire), and physical function (6-minute walk test). Participants with HFpEF (n = 59) were a mean of 64.6 ± 9.3 years old, 54% male, and 46% non-White with a mean ejection fraction of 55 ± 6%. Participants with HFpEF in the HEART Camp intervention group had significantly greater adherence compared with enhanced usual care at both 12 (43% vs 14%, phi = 0.32, medium effect) and 18 months (56% vs 0%, phi = 0.67, large effect). HEART Camp significantly improved walking distance on the 6-minute walk test (η² = 0.13, large effect) and the Kansas City Cardiomyopathy Questionnaire overall (η² = 0.09, medium effect), clinical summary (η² = 0.16, large effect), and total symptom (η² = 0.14, large effect) scores. In the HFrEF subgroup, only patient-reported anxiety improved significantly in the intervention group.

CONCLUSIONS

A multicomponent, behavioral intervention is associated with improvements in long-term adherence to exercise, physical function, and patient-reported outcomes in adults with HFpEF and anxiety in HFrEF. Our results provide a strong rationale for a large HFpEF clinical trial to validate these findings and examine interventional mechanisms and delivery modes that may further promote adherence and improve clinical outcomes in this population.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov/. Unique identifier: NCT01658670.

A Review of the Design and Implementation of a Hybrid Cardiac Rehabilitation Program: AN EXPANDING OPPORTUNITY FOR OPTIMIZING CARDIOVASCULAR CARE

PURPOSE

This review describes the considerations for the design and implementation of a hybrid cardiac rehabilitation (HYCR) program, a patient-individualized combination of facility-based cardiac rehabilitation (FBCR) with virtual cardiac rehabilitation (CR) and/or remote CR.

REVIEW METHODS

To help meet the goal of the Millions Hearts Initiative to increase CR participation to 70% by 2022, a targeted review of the literature was conducted to identify studies pertinent to the practical design and implementation of an HYCR program. Areas focused upon included the current use of HYCR, exercise programming considerations (eligibility and safety, exercise prescription, and patient monitoring), program assessments and outcomes, patient education, step-by-step instructions for billing and insurance reimbursement, patient and provider engagement strategies, and special considerations.

SUMMARY

A FBCR is the first choice for patient participation in CR, as it is supported by an extensive evidence base demonstrating effectiveness in decreasing cardiac and overall mortality, as well as improving functional capacity and quality of life. However, to attain the CR participation rate goal of 70% set by the Million Hearts Initiative, CR programming will need to be expanded beyond the confines of FBCR. In particular, HYCR programs will be necessary to supplement FBCR and will be particularly useful for the many patients with geographic or work-related barriers to participation in an FBCR program. Research is ongoing and needed to develop optimal programming for HYCR.

Update on RFA Increasing Use of Cardiac and Pulmonary Rehabilitation in Traditional and Community Settings NIH-Funded Trials: ADDRESSING CLINICAL TRIAL CHALLENGES PRESENTED BY THE COVID-19 PANDEMIC

We previously described the design of six NIH-funded clinical trials designed to increase uptake and reduce disparities in the use of cardiac rehabilitation (CR) and pulmonary rehabilitation (PR) based on age, gender, race/ethnicity, and socioeconomic status. The onset of the COVID-19 global pandemic necessitated signifi cant revisions to the trials to ensure the safety of participants and research staff. This article described necessary modifi cations for assessments, interventions, and data collection to support a no-contact approach centered on the use of virtual/remote techniques that maintain both safety and the original intent and integrity of the trials. The general shift from site-based to home-based interventions and hybrid models of CR and PR will be increasingly important in a post-COVID world.

Prognostic Value of Cardiorespiratory Fitness in Patients with Chronic Kidney Disease: The FIT (Henry Ford Exercise Testing) Project

PURPOSE

We conducted this study to investigate the association of cardiorespiratory fitness and all-cause mortality among patients with chronic kidney disease.

METHODS

We studied a retrospective cohort of patients from the Henry Ford Health System who underwent clinically indicated exercise stress testing with baseline cardiorespiratory fitness and estimated glomerular filtration rate measurement. Cardiorespiratory fitness was expressed as metabolic equivalents of task, and kidney function was categorized into stages according to estimated glomerular filtration rate. Multivariable-adjusted Cox proportional hazard models were used to examine the association between metabolic equivalents of task and all-cause mortality among patients with chronic kidney disease stages 3-5. Discrimination of mortality was assessed using receiver operating characteristic curves, while reclassification was evaluated using net reclassification index (NRI).

RESULTS

Among 50,121 participants, the mean age was 55 ± 12.6 years; 47.5% were women, 64.5% were white, and 6877 (13.7%) participants had chronic kidney disease stage 3-5. Over a median follow-up of 6.7 years, 6308 participants died (12.6%). Each 1-unit higher metabolic equivalents of task was associated with a significant 15% reduction in all-cause mortality (hazard ratio 0.85; 95% confidence interval [CI], 0.84-0.87). Metabolic equivalents of task improved discriminatory ability of mortality prediction when added to traditional risk factors and estimated glomerular filtration rate (area under the curve 0.7996; 95% CI, 0.789-0.810 vs 0.759; 95% CI, 0.748-0.770, respectively; P < .001). The addition of metabolic equivalents of task to traditional risk factors resulted in significant reclassification (6% for events, 5% for non-events: NRI = 0.13, P < .001).

CONCLUSIONS

Cardiorespiratory fitness improves mortality risk prediction among patients with chronic kidney disease. Cardiorespiratory fitness provides incremental prognostic information when added to traditional risk factors and may help guide treatment options among patients with renal dysfunction.

Exercise in patients with left ventricular devices: The interaction between the device and the patient

Advances in the engineering of surgically implanted, durable left ventricular assist devices (LVAD) has led to improvements in the two-year survival of patients on LVAD support, which is now comparable to that of heart transplant (HT) recipients. And with the advent of magnetic levitation technology, both the survival rate and average time on LVAD support are expected to improve even further. However, despite these advances, the functional capacity of patients on LVAD support remains reduced compared to those who received a HT. A few small clinical trials have shown improvement in functional capacity with exercise training. Peak oxygen uptake improves modestly (10%-20%) with exercise training, suggesting a possible celling-effect linked to the ability of the LVAD to increase flow during exercise. This paper reviews both (a) the effect of the LVAD on the cardiorespiratory responses during a single, acute bout of exercise up to maximum and (b) the central and peripheral adaptations that occur among patients with an LVAD who undergo an exercise training regimen. We also address the tenets of the exercise prescription that are unique to patients with a durable LVAD.

Hospital and Operator Variation in Cardiac Rehabilitation Referral and Participation After Percutaneous Coronary Intervention: Insights From Blue Cross Blue Shield of Michigan Cardiovascular Consortium

BACKGROUND

Despite its established benefit and strong endorsement in international guidelines, cardiac rehabilitation (CR) use remains low. Identifying determinants of CR referral and use may help develop targeted policies and quality improvement efforts. We evaluated the variation in CR referral and use across percutaneous coronary intervention (PCI) hospitals and operators.

METHODS

We performed a retrospective observational cohort study of all patients who underwent PCI at 48 nonfederal Michigan hospitals between January 1, 2012 and March 31, 2018 and who had their PCI clinical registry record linked to administrative claims data. The primary outcomes included in-hospital CR referral and CR participation, defined as at least one outpatient CR visit within 90 days of discharge. Bayesian hierarchical regression models were fit to evaluate the association between PCI hospital and operator with CR referral and use after adjusting for patient characteristics.

RESULTS

Among 54 217 patients who underwent PCI, 76.3% received an in-hospital referral for CR, and 27.1% attended CR within 90 days after discharge. There was significant hospital and operator level variation in in-hospital CR referral with median odds ratios of 3.88 (95% credible interval [CI], 3.06-5.42) and 1.64 (95% CI, 1.55-1.75), respectively, and in CR participation with median odds ratios of 1.83 (95% CI, 1.63-2.15) and 1.40 (95% CI, 1.35-1.47), respectively. In-hospital CR referral was significantly associated with an increased likelihood of CR participation (adjusted odds ratio, 1.75 [95% CI, 1.52-2.01]), and this association varied by treating PCI hospital (odds ratio range, 0.92-3.75) and operator (odds ratio range, 1.26-2.82).

CONCLUSIONS

In-hospital CR referral and 90-day CR use after PCI varied significantly by hospital and operator. The association of in-hospital CR referral with downstream CR use also varied across hospitals and less so across operators suggesting that specific hospitals and operators may more effectively translate CR referrals into downstream use. Understanding the factors that explain this variation will be critical to developing strategies to improve CR participation overall.

Rethinking Rehabilitation: A REVIEW OF PATIENT POPULATIONS WHO CAN BENEFIT FROM CARDIAC REHABILITATION

Although cardiac rehabilitation (CR) is safe and highly effective for individuals with various cardiovascular health conditions, to date there are only seven diagnoses or procedures identified by the Centers for Medicare & Medicaid Services that qualify for referral. When considering the growing number of individuals with cardiovascular disease (CVD), or other health conditions that increase the risk for CVD, it is important to determine the extent for which CR could benefit these populations. Furthermore, there are some patients who may currently be eligible for CR (spontaneous coronary artery dissection, left ventricular assistant device) but make up a relatively small proportion of the populations that are regularly attending and participating. Thus, these patient populations and special considerations for exercise might be less familiar to professionals who are supervising their programs. The purpose of this review is to summarize the current literature surrounding exercise testing and programming among four specific patient populations that either do not currently qualify for (chronic and end-stage renal disease, breast cancer survivor) or who are eligible but less commonly seen in CR (sudden coronary artery dissection, left ventricular assist device). While current evidence suggests that individuals with these health conditions can safely participate in and may benefit from supervised exercise programming, there is an immediate need for high-quality, multisite clinical trials to develop more specific exercise recommendations and support the inclusion of these populations in future CR programs.

Million Hearts Cardiac Rehabilitation Think Tank: Accelerating New Care Models

This article describes the October 2020 proceedings of the Million Hearts Cardiac Rehabilitation Think Tank: Accelerating New Care Models, convened with representatives from professional organizations, cardiac rehabilitation (CR) programs, academic institutions, federal agencies, payers, and patient representative groups. As CR delivery evolves, terminology is evolving to reflect not where activities occur (eg, center, home) but how CR is delivered: in-person synchronous, synchronous with real-time audiovisual communication (virtual), or asynchronous (remote). Patients and CR staff may interact through ≥1 delivery modes. Though new models may change how CR is delivered and who can access CR, new models should not change what is delivered-a multidisciplinary program addressing CR core components. During the coronavirus disease 2019 (COVID-19) public health emergency, Medicare issued waivers to allow virtual CR; it is unclear whether these waivers will become permanent policy post-public health emergency. Given CR underuse and disparities in delivery, new models must equitably address patient and health system contributors to disparities. Strategies for implementing new CR care models address safety, exercise prescription, monitoring, and education. The available evidence supports the efficacy and safety of new CR care models. Still, additional research should study diverse populations, impact on patient-centered outcomes, effect on long-term outcomes and health care utilization, and implementation in diverse settings. CR is evolving to include in-person synchronous, virtual, and remote modes of delivery; there is significant enthusiasm for implementing new care models and learning how new care models can broaden access to CR, improve patient outcomes, and address health inequities.

Fitness and Mortality Among Persons 70 Years and Older Across the Spectrum of Cardiovascular Disease Risk Factor Burden: The FIT Project

OBJECTIVE

To determine whether fitness could improve mortality risk stratification among older adults compared with cardiovascular disease (CVD) risk factors.

METHODS

We examined 6509 patients 70 years of age and older without CVD from the Henry Ford ExercIse Testing Project (FIT Project) cohort. Patients performed a physician-referred treadmill stress test between 1991 and 2009. Traditional categorical CVD risk factors (hypertension, hyperlipidemia, diabetes, and smoking) were summed from 0 to 3 or more. Fitness was grouped as low, moderate, and high (<6, 6 to 9.9, and ≥10 metabolic equivalents of task). All-cause mortality was ascertained through US Social Security Death Master files. We calculated age-adjusted mortality rates, multivariable adjusted Cox proportional hazards, and Kaplan-Meier survival models.

RESULTS

Patients had a mean age of 75±4 years, and 3385 (52%) were women; during a mean follow-up of 9.4 years, there were 2526 deaths. A higher fitness level (P<.001), not lower CVD risk factor burden (P=.31), was associated with longer survival. The age-adjusted mortality rate per 1000 person-years was 56.7 for patients with low fitness and 0 risk factors compared with 24.9 for high fitness and 3 or more risk factors. Among patients with 3 or more risk factors, the adjusted mortality hazard was 0.68 (95% CI, 0.61 to 0.76) for moderate and 0.51 (95% CI, 0.44 to 0.60) for high fitness compared with the least fit.

CONCLUSION

Among persons aged 70 years and older, there was no significant difference in survival of patients with 0 vs 3 or more risk factors, but a higher fitness level identified older persons with good long-term survival regardless of CVD risk factor burden.

Fitness and prostate cancer screening, incidence, and mortality: Results from the Henry Ford Exercise Testing (FIT) Project

BACKGROUND

The relation between cardiorespiratory fitness (CRF) and prostate cancer is not well established. The objective of this study was to determine whether CRF is associated with prostate cancer screening, incidence, or mortality.

METHODS

The Henry Ford Exercise Testing Project is a retrospective cohort study of men aged 40 to 70 years without cancer who underwent physician-referred exercise stress testing from 1995 to 2009. CRF was quantified in metabolic equivalents of task (METs) (<6 [reference], 6-9, 10-11, and ≥12 METs), estimated from the peak workload achieved during a symptom-limited, maximal exercise stress test. Prostate-specific antigen (PSA) testing, incident prostate cancer, and all-cause mortality were analyzed with multivariable adjusted Poisson regression and Cox proportional hazard models.

RESULTS

In total, 22,827 men were included, of whom 739 developed prostate cancer, with a median follow-up of 7.5 years. Men who had high fitness (≥12 METs) had an 28% higher risk of PSA screening (95% CI, 1.2-1.3) compared with those who had low fitness (<6 METs. After adjusting for PSA screening, fitness was associated with higher prostate cancer incidence (men aged <55 years, P = .02; men aged >55 years, P ≤ .01), but not with advanced prostate cancer. Among the men who were diagnosed with prostate cancer, high fitness was associated with a 60% lower risk of all-cause mortality (95% CI, 0.2-0.9).

CONCLUSIONS

Although men with high fitness are more likely to undergo PSA screening, this does not fully account for the increased incidence of prostate cancer seen among these individuals. However, men with high fitness have a lower risk of death after a prostate cancer diagnosis, suggesting that the cancers identified may be low-risk with little impact on long-term outcomes.

Determinants of Hospital Variation in Cardiac Rehabilitation Enrollment During Coronary Artery Disease Episodes of Care

BACKGROUND

Cardiac rehabilitation (CR) is associated with improved outcomes for patients with coronary artery disease (CAD). However, CR enrollment remains low and there is a dearth of real-world data on hospital-level variation in CR enrollment. We sought to explore determinants of hospital variability in CR enrollment during CAD episodes of care: medical management of acute myocardial infarction (AMI-MM), percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG).

METHODS

A cohort of 71 703 CAD episodes of care were identified from 33 hospitals in the Michigan Value Collaborative statewide multipayer registry (2015 to 2018). CR enrollment was defined using professional and facility claims and compared across treatment strategies: AMI-MM (n=18 678), PCI (n=41 986), and CABG (n=11 039). Hierarchical logistic regression was used to estimate effects of predictors and hospital risk-adjusted rates of CR enrollment.

RESULTS

Overall, 20 613 (28.8%) patients enrolled in CR, with significant differences by treatment strategy: AMI-MM=13.4%, PCI=29.0%, CABG=53.8% (P<0.001). There were significant differences in CR enrollment across age groups, comorbidity status, and payer status. At the hospital-level, there was over 5-fold variation in hospital risk-adjusted CR enrollment rates (9.8%-51.6%). Hospital-level CR enrollment rates were highly correlated across treatment strategy, with the strongest correlation between AMI-MM versus PCI (R²=0.72), followed by PCI versus CABG (R²=0.51) and AMI-MM versus CABG (R²=0.46, all P<0.001).

CONCLUSIONS

Substantial variation exists in CR enrollment during CAD episodes of care across hospitals. However, within-hospital CR enrollment rates were significantly correlated across all treatment strategies. These findings suggest that CR enrollment during CAD episodes of care is the product of hospital-specific rather than treatment-specific practice patterns.

Inverse Relationship of Maximal Exercise Capacity to Hospitalization Secondary to Coronavirus Disease 2019

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Abstract 4348: Cardiorespiratory fitness levels in men who develop prostate cancer and its association with all-cause mortality

Background: Cardiorespiratory fitness (CRF) is associated with a reduction in both cancer- and cardiovascular-specific mortality. In men however, little is known about the impact of pre-diagnostic CRF on mortality after prostate cancer. We hypothesized that among men with prostate cancer, low levels of CRF, measured prior to diagnosis, are associated with a higher risk of all-cause mortality.

Methods: From the Henry Ford FIT Project, a cohort of 37,730 men who underwent clinically-indicated exercise stress test from 1991 through 2009, we identified 1,440 men who developed prostate cancer after stress test. CRF was measured in peak metabolic equivalents of task (METs) and categorized as less than 6, 6 to 9, 10 to 11, and at least 12 (reference). Multivariable Cox proportional hazard models were developed to evaluate the association between CRF, measured prior to prostate cancer diagnosis, and all-cause mortality. Models were adjusted for age at prostate cancer diagnosis (baseline), race, BMI, current aspirin and statin use, smoking history, hypertension, diabetes, prior cardiovascular disease (myocardial infarction and heart failure), time from stress test to prostate cancer diagnosis, and cancer stage (local, regional, distant) at diagnosis.

Results: Mean age at time of stress test was 61 +/- 9 yr (57% white, 39% black), with 7 (+/-4) yrs of follow up after prostate cancer diagnosis. 81% of men were diagnosed with localized prostate cancer; 15% with regional disease, and 2% with distant metastatic disease. Mean time from stress test to diagnosis was 6 +/- 5 yrs. Mean METs achieved was 9 (+/- 3). Patients with low fitness (METs less than 6) before diagnosis had 2.6 times the risk of all-cause mortality (95% CI 1.6-4.2) compared to those with high fitness (METS at least 12). Those with CRF of 6-9 METs had 1.9 times the risk (95% CI 1.2-3.0). The risk of mortality was not different between the two highest fitness groups (P= 0.71; P for trend across all fitness groups less than 0.01). Results were similar when stratified by race.

Conclusion: Low CRF prior to the diagnosis of prostate cancer in men is associated with a higher risk of all-cause mortality. This study highlights the prognostic importance of fitness even before a cancer diagnosis.

Citation Format: Cara Reiter-Brennan, Omar Dzaye, Mouaz H. Al-Mallah, Zeina Dardari, Clinton A. Brawner, Lois E. Lamerato, Steven J. Keteyian, Jonathan K. Ehrman, Kala Visvanathan, Michael J. Blaha, Catherine Handy Marshall. Cardiorespiratory fitness levels in men who develop prostate cancer and its association with all-cause mortality [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4348.

Abstract 5773: Cardiorespiratory fitness and PSA screening patterns in the Henry Ford FIT Project

Background: High levels of cardiorespiratory fitness (CRF) have been associated with a decreased risk of many cancers, but the association with prostate cancer (PCa) is less clear. A possible explanation for the lack of consistency is that prostate specific antigen (PSA) screening and in turn prostate cancer detection is more frequent in men with higher fitness although the relationship between fitness and PSA screening is not established.

Methods: The Henry Ford (HF) FIT Project is a retrospective cohort study of 69,894 consecutive patients who underwent physician-referred exercise stress testing from 1991 through 2009. Cancer diagnosis was identified through linkage to the HF tumor registry. We included men aged 40-70 yr who had CRF testing beginning in 1995 (when PSA screening became widespread), without prevalent cancer, followed at least 3 yrs and up to 10 years, who never develop prostate cancer (n=12,442). CRF was measured in metabolic equivalents of task (METs) and categorized as less than 6 (ref), 6-9, 10-11, and at least 12. PSA values were abstracted from the HF electronic medical record between 1995 and 2010. Individuals with at least 3 screening PSA tests were categorized as high screeners. Logistic regression was used to evaluate the relationship between CRF and high PSA screeners, adjusted for age at stress test and race.

Results: Participants had a mean age of 54 ± 8 yrs (67% white; 25% black) and mean follow-up was 7±2 yrs. Compared to individuals with low fitness (less than 6 METs, reference), those with higher fitness (6-9, 10-11, at least 12 METs) had higher odds of being a high PSA screener (Table). When stratified by race, the OR for black patients were not statistically different than white patients (Table). Results were similar among those with comorbidities (myocardial infarction, heart failure, or diabetes) at baseline.

Odds ratio of being a high screener (at least 3 PSA tests) in individuals followed 3-10 yearsMETs categoryAll (n=12,442Whites (n=8,356Blacks (n=3,049)Patients w/comorbidities (n=3,924)&lt;6RefRefRefRef6-91.6(1.3-1.8)1.6(1.3-2.0)1.4(1.1-1.9)1.6(1.3-2.0)10-111.9(1.6-2.2)1.9(1.6-2.4)1.7(1.3-2.2)2.0(1.7-2.4)&gt;=122.4 (2.1-2.9)2.5(2.0-3.1)2.1(1.6-2.8)3.2(2.5-4.0)

Conclusion: High CRF is associated with more frequent PSA screening. This points towards a healthy screening bias and should be accounted for in studies looking at fitness and incident prostate cancer.

Citation Format: Cara Reiter-Brennan, Omar Dzaye, Mouaz H. Al-Mallah, Zeina Dardari, Clinton A. Brawner, Lois E. Lamerato, Steven J. Keteyian, Jonathan K. Ehrman, Kala Visvanathan, Michael J. Blaha, Catherine Handy Marshall. Cardiorespiratory fitness and PSA screening patterns in the Henry Ford FIT Project [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5773.

Cardiorespiratory Fitness and Incident Stroke Types: The FIT (Henry Ford ExercIse Testing) Project

OBJECTIVE

To study the association between cardiorespiratory fitness (CRF) and incident stroke types.

PATIENTS AND METHODS

We studied a retrospective cohort of patients referred for treadmill stress testing in the Henry Ford Health System (Henry Ford ExercIse Testing Project) without history of stroke. CRF was expressed by metabolic equivalents of task (METs). Using appropriate International Classification of Diseases, Ninth Revision codes, incident stroke was ascertained through linkage with administrative claims files and classified as ischemic, hemorrhagic, and subarachnoid hemorrhage (SAH). Multivariable-adjusted Cox proportional hazards models examined the association between CRF and incident stroke.

RESULTS

Among 67,550 patients, mean ± SD age was 54±13 years, 46% (n=31,089) were women, and 64% (n=43,274) were white. After a median follow-up of 5.4 (interquartile range 2.7-8.5) years, a total of 7512 incident strokes occurred (6320 ischemic, 2481 hemorrhagic, and 275 SAH). Overall, there was a graded lower incidence of stroke with higher MET categories. Patients with METs of 12 or more had lower risk of overall stroke [0.42 (95% CI, 0.36-0.49)], ischemic stroke [0.69 (95% CI, 0.58-0.82)], and hemorrhagic stroke [0.71 (95% CI, 0.52-0.95)].

CONCLUSION

In a large ethnically diverse cohort of patients referred for treadmill stress testing, CRF is inversely associated with risk for ischemic and hemorrhagic stroke.

Association of BMI, Fitness, and Mortality in Patients With Diabetes: Evaluating the Obesity Paradox in the Henry Ford Exercise Testing Project (FIT Project) Cohort

OBJECTIVE

To determine the effect of fitness on the association between BMI and mortality among patients with diabetes.

RESEARCH DESIGN AND METHODS

We identified 8,528 patients with diabetes (self-report, medication use, or electronic medical record diagnosis) from the Henry Ford Exercise Testing Project (FIT Project). Patients with a BMI <18.5 kg/m² or cancer were excluded. Fitness was measured as the METs achieved during a physician-referred treadmill stress test and categorized as low (<6), moderate (6-9.9), or high (≥10). Adjusted hazard ratios for mortality were calculated using standard BMI (kilograms per meter squared) cutoffs of normal (18.5-24.9), overweight (25-29.9), and obese (≥30). Adjusted splines centered at 22.5 kg/m² were used to examine BMI as a continuous variable.

RESULTS

Patients had a mean age of 58 ± 11 years (49% women) with 1,319 deaths over a mean follow-up of 10.0 ± 4.1 years. Overall, obese patients had a 30% lower mortality hazard (P < 0.001) compared with normal-weight patients. In adjusted spline modeling, higher BMI as a continuous variable was predominantly associated with a lower mortality risk in the lowest fitness group and among patients with moderate fitness and BMI ≥30 kg/m². Compared with the lowest fitness group, patients with higher fitness had an ∼50% (6-9.9 METs) and 70% (≥10 METs) lower mortality hazard regardless of BMI (P < 0.001).

CONCLUSIONS

Among patients with diabetes, the obesity paradox was less pronounced for patients with the highest fitness level, and these patients also had the lowest risk of mortality.

Tracking Cardiac Rehabilitation Participation and Completion Among Medicare Beneficiaries to Inform the Efforts of a National Initiative

BACKGROUND

Despite cardiac rehabilitation (CR) being shown to improve health outcomes among patients with heart disease, its use has been suboptimal. In response, the Million Hearts Cardiac Rehabilitation Collaborative developed a road map to improve CR use, including increasing participation rates to ≥70% by 2022. This observational study provides current estimates to measure progress and identifies the populations and regions most at risk for CR service underutilization.

METHODS AND RESULTS

We identified Medicare fee-for-service beneficiaries who were CR eligible in 2016, and assessed CR participation (≥1 CR session attended), timely initiation (participation within 21 days of event), and completion (≥36 sessions attended) through 2017. Measures were assessed overall, by beneficiary characteristics and geography, and by primary CR-qualifying event type (acute myocardial infarction hospitalization; coronary artery bypass surgery; heart valve repair/replacement; percutaneous coronary intervention; or heart/heart-lung transplant). Among 366 103 CR-eligible beneficiaries, 89 327 (24.4%) participated in CR, of whom 24.3% initiated within 21 days and 26.9% completed CR. Eligibility was highest in the East South Central Census Division (14.8 per 1000). Participation decreased with increasing age, was lower among women (18.9%) compared with men (28.6%; adjusted prevalence ratio: 0.91 [95% CI, 0.90-0.93]) was lower among Hispanics (13.2%) and non-Hispanic blacks (13.6%) compared with non-Hispanic whites (25.8%; adjusted prevalence ratio: 0.63 [0.61-0.66] and 0.70 [0.67-0.72], respectively), and varied by hospital referral region and Census Division (range: 18.6% [East South Central] to 39.1% [West North Central]) and by qualifying event type (range: 7.1% [acute myocardial infarction without procedure] to 55.3% [coronary artery bypass surgery only]). Timely initiation varied by geography and qualifying event type; completion varied by geography.

CONCLUSIONS

Only 1 in 4 CR-eligible Medicare beneficiaries participated in CR and marked disparities were observed. Reinforcement of current effective strategies and development of new strategies will be critical to address the noted disparities and achieve the 70% participation goal.

The Interplay of the Global Atherosclerotic Cardiovascular Disease Risk Scoring and Cardiorespiratory Fitness for the Prediction of All-Cause Mortality and Myocardial Infarction: The Henry Ford ExercIse Testing Project (The FIT Project)

Cardiorespiratory fitness (CRF) is inversely associated with atherosclerotic cardiovascular disease (ASCVD) risk. It is unclear whether the prognostic value of CRF differs by baseline estimated ASCVD risk. We studied a retrospective cohort of patients without known heart failure or myocardial infarction (MI) who underwent treadmill stress testing. CRF was measured by metabolic equivalents of task (METs) and ASCVD risk was calculated using the Pooled Cohorts Equations. Multivariable-adjusted Cox regressions analyses examined the association between METs and incident all-cause mortality and MI outcomes stratified by baseline ASCVD risk. The C-index evaluated risk discrimination while net reclassification improvement evaluated reclassification with CRF added to the ASCVD risk score. Our study population consisted of 57,999 patients of mean age 53 (13) years, 49% women, 64% white, 29% black. Over a median follow-up 11 years (interquartile range 8 to 14 years) there were 6,670 (11%) deaths, while there were 1,757 (3.0%) MIs over a median follow-up of 6 years (interquartile range 3 to 8 years). Among patients with ASCVD risk ≥20%, those with METs ≥12 had a 77% lower risk of all-cause mortality (Hazard ratio 0.23 95% confidence interval = 0.20, 0.27) and 67% lower risk of MI (Hazard ratio 0.33 95% confidence interval = 0.24, 0.46) compared to METs <6. Similar results were obtained for those with ASCVD risk <5%. Addition of METs to ASCVD risk score improved the C-statistic from 0.778 to 0.798 for all-cause mortality and 0.726 to 0.733 for MI (both p <0.001). Addition of METs to ASCVD risk score significantly reclassified risk of all-cause mortality (p <0.001) but not MI (p = 0.052). In conclusion, CRF is inversely associated with risk of all-cause mortality and MI at all levels of ASCVD risk, and provides incremental risk discrimination and reclassification beyond the ASCVD risk score.

The influence of the HEART Camp intervention on physical function, health-related quality of life, depression, anxiety and fatigue in patients with heart failure

BACKGROUND

Regular exercise training has beneficial effects on quality of life, physical function, depression and anxiety in individuals with heart failure. Unfortunately, individuals with heart failure have low levels of adherence to exercise. Thus, studies are needed to assess intervention strategies which may enhance clinical outcomes.

AIM

The aim of this study was to identify the components of the HEART Camp intervention, which contributed to optimizing clinical outcomes.

METHODS

The Heart Failure Exercise and Resistance Training Camp (HEART Camp) was a randomized controlled trial to evaluate the effect of a multicomponent intervention on adherence to exercise (6, 12 and 18 months) compared to an enhanced usual care group. This study assessed various components of the intervention on the secondary outcomes of physical function, health-related quality of life, depression, anxiety, and fatigue.

RESULTS

Individuals participating (n=204) in this study were 55.4% men and the average age was 60.4 (11.5) years. A combination of individualized and group-based strategies demonstrated clinical improvements, HEART Camp versus enhanced usual care groups, in physical function, positive trends in health-related quality of life and positive changes in the minimally important differences for depression, anxiety, and fatigue.

CONCLUSIONS

Individualized coaching by an exercise professional and group-based educational sessions were identified as important components of patient management contributing to improvements in the secondary outcomes of physical function, health-related quality of life, depression, anxiety and fatigue.

Use of Sex-Specific Clinical and Exercise Risk Scores to Identify Patients at Increased Risk for All-Cause Mortality

Importance

Risk assessment tools for exercise treadmill testing may have limited external validity. Cardiovascular mortality has decreased in recent decades, and women have been underrepresented in prior cohorts.

Objectives

To determine whether exercise and clinical variables are associated with differential mortality outcomes in men and women and to assess whether sex-specific risk scores better estimate all-cause mortality.

Design, Setting, and Participants

This retrospective cohort study included 59 877 patients seen at the Cleveland Clinic Foundation (CCF cohort) from January 1, 2000, through December 31, 2010, and 49 278 patients seen at the Henry Ford Hospital (FIT cohort) from January 1, 1991, through December 31, 2009. All patients were 18 years or older and underwent exercise treadmill testing. Data were analyzed from January 1, 2000, to October 27, 2011, in the CCF cohort and from January 1, 1991, to April 1, 2013, in the FIT cohort.

Main Outcomes and Measurements

The CCF cohort was divided randomly into derivation and validation samples, and separate risk scores were developed for men and women. Net reclassification, C statistics, and integrated discrimination improvement were used to compare the sex-specific risk scores with other tools that have all-cause mortality as the outcome. Discrimination and calibration were also evaluated with these sex-specific risk scores in the FIT cohort.

Results

The CCF cohort included 59 877 patients (59.4% men; 40.5% women) with a median (interquartile range [IQR]) age of 54 (45-63) years and 2521 deaths (4.2%) during a median follow-up of 7 (IQR, 4.1-9.6) years. The FIT cohort included 49 278 patients (52.5% men; 47.4% women) with a median (IQR) age of 54 (46-64) years and 6643 deaths (13.5%) during a median (IQR) follow-up of 10.2 (7-13.4) years. C statistics for the sex-specific risk scores in the CCF validation sample were higher (0.79 in women and 0.81 in men) than C statistics using other tools in women (0.70 for Duke Treadmill Score; 0.74 for Lauer nomogram) and men (0.72 for Duke Treadmill Score; 0.75 for Lauer nomogram). Net reclassification and integrated discrimination improvement were superior with the sex-specific risk scores, mostly owing to correct reclassification of events. The sex-specific risk scores in the FIT cohort demonstrated similar discrimination (C statistic, 0.78 for women and 0.79 for men), and calibration was reasonable.

Conclusions and Relevance

Sex-specific risk scores better estimate mortality in patients undergoing exercise treadmill testing. In particular, these sex-specific risk scores help to identify patients at the highest residual risk in the present era.