Olson, Thomas P.

Background Cardiac rehabilitation (CR) improves peak oxygen uptake (VO 2 peak) and body composition in patients with cardiovascular disease. However, improvement in VO 2 peak is not observed in all patients following a CR program, and whether VO 2 peak non-responders also demonstrate limited changes in body composition remains unclear. This study aimed to examine the association between changes in VO 2 peak and body composition in patients undergoing a CR program. Methods Retrospective analysis of patients who completed CR between 2015 and 2022 at Mayo Clinic. The study included 143 patients who completed cardiopulmonary exercise testing and dual-energy X-ray absorptiometry pre- and post-CR. Patients were grouped by the change in relative VO 2 peak response to CR (responders= Δ>0 vs non-responders=Δ ≤0 mL/kg/min). Two-way repeated ANOVA was used to compare groups, and regression models were used to examine the associations between baseline body composition and changes in body composition with VO 2 peak change. Results Among the cohort, 26% were classified as non-responders based on relative VO 2 peak measurements. Both groups exhibited a significant improvement in most body composition variables including body fat mass, body fat percentage, body lean percentage, and fat mass index (all p<0.001), with no differences in the percentage of change in body composition variables between groups (p>0.05). Regression models demonstrated that neither baseline body composition nor changes in body composition were significantly associated with changes in VO 2 peak. Conclusion Our data suggest that baseline and change in body composition were not significantly associated with changes in VO 2 peak in patients undergoing the CR program.

Background Cardiac rehabilitation (CR) leads to increased exercise capacity (VO 2 peak) and risk reduction of major adverse cardiovascular events (MACEs). Women exhibit blunted VO 2 peak improvements following CR. The purpose was to examine sex differences in the clinical predictors of VO 2 peak improvement and odds of MACEs following CR. Methods From 1999 to 2017, all consecutive patients undergoing cardiopulmonary exercise testing before and after CR were included. Sex differences in peak exercise metrics in response to CR were compared. Multiple logistic regression models were fit to assess clinical predictors of VO 2 peak improvement (defined as >0% from pre‐CR) and MACEs following CR for men and women. Results A total of 513 men and 158 women were included. Men had greater increases in VO 2 peak than women following CR ( P =0.001). For men, independent predictors of VO 2 peak improvement following CR included higher CR session attendance (odds ratio [OR], 1.04 [95% CI, 1.02–1.06]), peripheral artery disease (OR, 0.47 [95% CI, 0.25–0.86]), and pre‐CR VO 2 peak (OR, 0.98 [95% CI, 0.97–0.99]) (all, P <0.02). Independent predictors of lower odds of MACEs following CR in men included higher number of CR sessions (OR, 0.97 [95% CI, 0.95–0.99]), pre‐CR VO 2 peak (OR, 0.98 [95% CI, 0.97–0.99]), surgical CR indication (OR, 0.34 [95% CI, 0.18–0.68]), and no history of peripheral artery disease (OR, 2.94 [95% CI, 1.60–5.38]) (all, P <0.02). For women, the selected clinical characteristics were not statistically significant independent predictors of VO 2 peak improvement or odds of MACEs (except for diabetes) following CR. Conclusions These findings suggest that clinical predictors of VO 2 peak improvement and odds of MACEs following CR are sex specific.

Heart failure with preserved ejection fraction (HFpEF) is associated with exercise intolerance, with respiratory muscle dysfunction as a contributing factor. Patients with HFpEF have exaggerated cardiovascular responses to respiratory muscle metaboreflex activation. In this study, we determined the impact of inspiratory muscle training (IMT) on the respiratory muscle metaboreflex in HFpEF. We found that 8 wk of IMT improved inspiratory muscle strength and attenuated the respiratory muscle metaboreflex-mediated cardiovascular responses in patients with HFpEF.

Background Cardiac rehabilitation (CR) is a comprehensive secondary cardiovascular disease program with structured lifestyle interventions to reduce morbidity and mortality. The American Heart Association cardiovascular health (CVH) framework measures health‐promoting behaviors and clinical factors, but it has not been rigorously evaluated in the CR setting. Methods This retrospective cohort study analyzed patients attending CR from January 2018 to September 2020. Patients were evaluated at baseline (pre‐CR) and completion (post‐CR) using 3 clinical factors (blood pressure, cholesterol, and hemoglobin A1c) and 4 health behaviors (smoking, body mass index, physical activity, and diet). CVH score was computed as a composite of each Life's Simple 7 component by assigning 0 points for poor, 1 point for intermediate, or 2 points for ideal (range 0–14 points). CVH scores were further categorized as poor (0–6 points), intermediate (7–8 points), and ideal (9–14 points). Missing data in the analysis were accounted for using a multiple imputation procedure. Results Patients (N=937) were aged 64.0±13.4 years old, 34% women, and attended 11±12 CR sessions. Pre‐CR, 97.2% had poor CVH scores, 2.8% had intermediate scores, and none met ideal CVH criteria. Post‐CR, there was a reduction in poor scores across all metrics except for hemoglobin A1c, which increased (40.6%–43.5%). Younger patients showed improvement in hemoglobin A1c, while older patients improved in body mass index and blood pressure. Conclusions Our study demonstrates the efficacy of CR in improving CVH but underscores the need for better blood glucose management. Tailored interventions based on age and sex may further optimize outcomes for CR participants.

Background: Cardiac rehabilitation (CR) is essential to secondary cardiovascular disease prevention and management of cardiac patients. Despite its proven benefits, CR remains underutilized with enrollment and completion rates ranging from 10-30% in the US. Yet, there is a scarcity of nationally representative data among diverse populations on socioeconomic differences in barriers and beliefs of CR participation and delivery mode preferences. Hypothesis: The perceptions (barriers, beliefs), CR delivery mode preferences, and CR utilization (prior enrollment) varies by socioeconomic status (SES) among CR-eligible individuals. Methods: We conducted an anonymous national electronic survey from March 2023 to January 2024 of individuals self-reporting a prior CR-eligible diagnosis. The 22-item CR Barriers Scale assessed perceived barriers to CR enrollment and participation using a 5-point Likert scale (strongly disagree to strongly agree). A 13-item, validated questionnaire assessed 4 subscales pertaining to patients’ beliefs about CR, each rated on a 5-point Likert scale (strongly disagree to strongly agree): perceived necessity, concerns about exercise, practical barriers and perceived suitability. CR delivery mode preferences were ascertained (eg, virtual, at-home, etc.). Mean barriers and belief scores as well as delivery mode preferences were stratified by SES. Low SES was defined as ≤ high school education, Medicaid insurance, or uninsured. High SES was defined as > high school education and non-Medicaid health insurance. Responses were analyzed using descriptive statistics with R software. Results: A total of 466 participants completed the survey (38.1% women, 30.6% minoritized racial/ethnic group, 29.6% low SES, 95% response rate) ( Table 1 ). The majority indicated prior enrollment in CR (81.5%) with no difference by SES. CR barrier scores did not differ significantly by SES (p=0.331) ( Table 2 ). Beliefs about CR perceived necessity and perceived suitability differed by SES (p<0.001 and p=0.025), but beliefs regarding concerns about exercise and practical barriers did not. The low SES group reported a higher preference for completely at-home CR compared to the high SES group (33.6% vs 7.4%, p<0.001). Conclusion: Our findings suggest that CR beliefs varied by SES while utilization did not. For CR-eligible patients experiencing socioeconomic disadvantage, at-home CR may be a preferred alternative to center-based CR to increase CR participation and adherence.

This cohort study examines changes in oxygen consumption among patients with multiple morbidities undergoing cardiac rehabilitation.

Introduction: Peak oxygen uptake (VO 2 peak), standardized to total body mass (ml/kg/min) is a predictor of morbidity and mortality in cardiovascular disease patients. However, subsets of individuals undergoing exercise based cardiac rehabilitation (CR) show no improvement or reduction in VO 2 peak despite improvement in other functional measures. Hypothesis: Change in peak VO 2 post-CR, adjusted for lean mass rather than total mass better reflects peak VO 2 improvements. Aim : To assess the influence of CR on lean mass and the effect of lean mass compared to total body mass changes on peak VO 2 following CR. Methods: This observational cohort study included adults >18 years old who completed CR between 2015-2022 at Mayo Clinic, Rochester. All patients completed both dual energy X-ray absorptiometry (DXA) and cardiopulmonary exercise testing (CPET) for measurement of body composition (total mass and lean mass) and VO 2 peak pre- and post-CR. Improvement in VO 2 peak was defined as >% increase. Paired t-tests, one-way ANOVA, and descriptive statistics were performed. Results: Of 145 subjects, 81% were male and 63% Caucasian with a mean (SD) age of 62.8±12.6 years, BMI of 30.3±5.7, and 33.4±8.2 of 36 prescribed (92.8%) CR sessions completed. Pre-CR, patients demonstrated absolute VO 2 peak of 1,997.0±693.5 mL/min, relative of 22.1±6.2 mL/kg/min, and relative to lean mass of 35.2±9.6 mL/kg lean/min. After CR, patients demonstrated 1.2±3.1 kg reduction in total mass (p<0.05) and 0.4±1.7 kg increase in lean mass (p<0.05). Post-CR VO 2 peak increased by 17.1±117.0% absolute units (mL/min) (p<0.05), 9.0±16.1 % relative units (mL/kg/min) (p<0.05), and 15.9±111.9% units relative to lean mass (mL/kg lean/min) (p<0.05). Absolute and relative to lean mass units demonstrated greater improvements in VO 2 peak compared to relative units (p<0.05). Dependent on units, 70.3% of patients demonstrated an improvement in absolute VO 2 , 75.2% patients improved relative VO 2 , and 62.8% patients improved VO 2 relative to lean mass. Conclusions: These data demonstrate significant increases in lean mass and VO 2 following CR, with larger improvements reflected in units adjusted for lean mass compared to traditional relative units. In contrast, the largest proportion of patients showed positive improvements in VO 2 peak relative units with the smallest proportion relative to lean mass. These data suggest the reporting methodology for change in VO 2 following CR may impact overall findings.