Squires, Ray W.

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.

Purpose: Subjects with normal weight obesity (NWO), defined as normal BMI but high body fat (BF)%, are at increased cardiovascular risk. Factors contributing to NWO are not well studied. We hypothesized that NWO is associated with reduced physical activity and unhealthy eating patterns. Methods: We analyzed 5942 people ≥18 years with normal BMI (18.5-24.9 kg/m 2 ) from the NHANES III survey (1988-1994), a representative sample of the US population. Subjects were classified as NWO based on BF% (>35% in women and >25% in men). Leisure-time physical activity was measured with a standard survey. Subjects were stratified as INACTIVE (no physical activity reported), ACTIVE (3-6 METs for ≥ 5 times/week or >6 METs, ≥3 times/week), or insufficiently active (those who were not INACTIVE but did not meet criteria for ACTIVE). Total activity was expressed in METs/hr/month, assuming an exercise duration of 30 minutes for each day reported. A Healthy Eating Index was based on 24-hour dietary recall data. Analyses were weighted for the complex study design. Results: Mean age was 43 years, 54.4% were men; 1170 people (19.7%) with normal BMI had NWO. Table shows demographics, physical activity and nutritional habits by group. After controlling for age, gender, poverty levels, smoking status and Healthy Eating Index, METs/hr/month was an independent predictor of NWO (OR per 100 MET/hours/month is 0.72(95%CI 0.60;0.88). People who were inactive and insufficiently active had higher odds of NWO as compared with active people (OR-1.47; 95%CI 1.10;1.96 and OR-1.60, 95% CI 1.25; 2.05, respectively). Also, strength training was independently associated with a decreased odds of NWO (0.63; 95%CI 0.44;0.89). Dietary pattern was not predictive of NWO. Conclusions: Physical activity, particularly resistance exercise, but not diet, was associated with NWO independently of potential confounders. Promoting physical activity may be an important interventional strategy in these patients.

Abstract Funding Acknowledgements Type of funding sources: None. Background Falls are the leading cause of injury-related morbidity and mortality among older adults in the United States, including those with cardiovascular disease. Cardiac rehabilitation (CR) helps to optimize functional capacity, strength, and balance in patients with cardiovascular disease and, in theory, may reduce the risk of falls. However, little evidence has been published in this regard. Purpose The purpose of this study was to assess the association between CR participation and risk of falls in a community-based sample of individuals 65 years of age and older with cardiovascular disease who were eligible for CR participation. Methods Individuals from Southeastern MN and Western WI, USA, 65 years of age and older who had experienced a cardiovascular event that qualified them for CR (MI, PCI, CABG, Valve Surgery, Transplant) between January 1, 2000, and December 31, 2018, were included in this study. Participation in CR (≥1 sessions, CR-group) and subsequent falls (moderate or severe, using the Campbell classification system) were ascertained using the Rochester Epidemiology Project records-linkage system. Logistic model to create propensity weighting were used to test the association between CR participation and falls after adjustment for potentially confounding factors. Results A total of 5004 individuals met inclusion criteria for the study, with 2183 (44%) included in the CR group and 2821 (56%) in the non-CR group (CR was indicated, but the individual did not participate). Overall, 1122 patients experienced a fall within the first 5 years (16% of those in the CR-group, 23% of those in the non-CR group). After adjustment, CR participation was not associated with falls, but older individuals, females, and those with a history of falls were more likely to have had a fall, compared to young individuals, males, and those without a history of a fall. Conclusions While CR is beneficial for patients with cardiovascular disease, our study did not find evidence of an association between CR participation and fall risk in individuals 65 years of age and older who have cardiovascular disease. Additional research is needed to evaluate the role of CR components that may potentially reduce modifiable risk factors for falls and thereby reduce the risk of falls.

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac rehabilitation (CR) is a key component in the continuum of care for patients with CVD that reduces mortality, morbidity and rehospitalization. Clinical practice guidelines strongly recommend and encourage CR participation for eligible patients with CVD. Although there are multiple studies on barriers and solutions to improve the initiation rates of CR, a limited number of studies have explored the barriers and solutions to increase the degree of adherence to CR. Purpose The aim of this study was to define those characteristics that predict adherence to CR with special focus on women and employed patients, since these groups are generally understudied. Methods We performed a retrospective electronic medical record review of the Mayo Clinic CR program, Rochester to identify patients who had started the Mayo Clinic program between January 1, 2014 and September 30, 2015. Among patients who met the inclusion criteria, we conducted a telephone survey with the aim of defining barriers to participation and possible solutions proposed by patients to increase CR adherence. The survey included factors previously identified in the literature as possible barriers, as well as other hypothetical factors; including closed and open-ended questions. The study was approved by the Mayo Clinic institutional review board. Results 376 patients met the inclusion criteria. 257 patients completed the survey. 240 (63.8%) returned the HIPAA (Health Information Use Authorization) document. 72 (30%) were women with a mean age of 66.4 ±12.4 years. Forty-seven percent (n = 113) of the participants did not complete the recommended course of 36 sessions of CR. Among the most important barriers, we found that schedule conflicts were more frequently noted to be a barrier to CR participation among employed patients compared to non-employed patients (p=0.04). Lack of motivation and an inadequate awareness of the importance of completing CR were significantly reported as barriers from employed and non-employed patients. Among the proposed solutions, the participants suggested the potential benefit of alternative delivery models for CR programs; as well efforts to improve awareness of the importance of CR adherence among patients and professionals. Conclusions This study has great relevance because it addressed barriers and potential solutions to CR adherence. Barriers such as mental stress and motivation, as well as a lack of knowledge about CR benefits highlight the role of patient counseling and education as keys to help improve CR adherence. Alternative CR delivery models are attractive options to help facilitate participation, with special focus on the employed population and women, as they more frequently report logistical barriers to CR compared to non-employed patients and men. Further research and advocacy work are needed to help identify and implement strategies that address barriers to CR adherence and completion.

Background: The role of minute ventilation/carbon dioxide production ( / CO2) slope, a ventilation efficiency marker, in predicting short-term and long-term health outcomes for patients with nonsmall-cell lung cancer (NSCLC) undergoing lung resection has not been well investigated. Material and Methods: This prospective cohort study consecutively enrolled NSCLC patients who underwent a presurgical cardiopulmonary exercise test from November 2014 to December 2019. The association of / CO2 slope with relapse-free survival (RFS), overall survival (OS), and perioperative mortality was evaluated using the Cox proportional hazards and logistic models. Covariates were adjusted using propensity score overlap weighting. The optimal cut-off point of the E/ CO2 slope was estimated using the receiver operating characteristics curve. Internal validation was completed through bootstrap resampling. Results: A cohort of 895 patients [median age (interquartile range), 59 (13) years; 62.5% male] was followed for a median of 40 (range, 1–85) months. Throughout the study, there were 247 relapses or deaths and 156 perioperative complications. The incidence rates per 1000 person-years for relapses or deaths were 108.8 and 79.6 among patients with high and low E/ CO2 slopes, respectively [weighted incidence rate difference per 1000 person-years, 29.21 (95% CI, 7.30–51.12)]. A E/ CO2 slope of greater than or equal to 31 was associated with shorter RFS [hazard ratio for relapse or death, 1.38 (95% CI, 1.02–1.88), P=0.04] and poorer OS [hazard ratio for death, 1.69 (1.15–2.48), P=0.02] compared to a lower / CO2 slope. A high E/ CO2 slope increased the risk of perioperative morbidity compared with a low E/ CO2 slope [odds ratio, 2.32 (1.54–3.49), P<0.001]. Conclusions: In patients with operable NSCLC, a high E/ CO2 slope was significantly associated with elevated risks of poorer RFS, OS, and perioperative morbidity.

ABSTRACT Introduction Peak rating of perceived exertion (RPE) is measured during clinical cardiopulmonary exercise testing (CPX) and is commonly used as a subjective indicator of maximal effort. However, no study to date has reported reference standards or the distribution of peak RPE across a large cohort of apparently healthy individuals. Purpose This study aimed to determine reference standards for peak RPE when using the 6–20 Borg scale for both treadmill and cycle tests. Methods The analysis included 9551 tests (8821 treadmill, 730 cycle ergometer) from 13 laboratories within the Fitness Registry and Importance of Exercise National Database (FRIEND). Using data from tests conducted January 1, 1980, to January 1, 2021, percentiles of peak RPE for men and women were determined for each decade from 20 to 89 yr of age for treadmill and cycle exercise modes. Two-way ANOVA was used to compare differences in peak RPE values between sexes and across age groups. Results There were statistically significant differences in RPE between age groups whether the test was performed on a treadmill or cycle ergometer ( P < 0.05). However, the mean and median RPE for each sex, age group, and test mode were between 18 and 19. In addition, 83% of participants met the traditional RPE criteria of ≥18 for indicating sufficient maximal effort. Conclusions This report provides the first normative reference standards for peak RPE in both male and female individuals performing CPX on a treadmill or cycle ergometer. Furthermore, these reference standards highlight the general consistency of peak RPE responses during CPX.

Background: COVID-19 reveals new manifestations not only in the acute phase but also in the long term. The latter is what has been termed as ‘post acute sequelae of SARS-CoV-2 infection’ (PASC) — or “long COVID”— with dyspnea as one of its hallmarks. Cardiopulmonary stress testing (CPET) is increasingly being used to better evaluate such patients. Objective: To compare CPET findings of long COVID patients versus non-COVID patients with undifferentiated dyspnea on exertion seen at Mayo Clinic. Methods: A cohort study was carried out using Mayo Clinic’s exercise testing database. The study group included 77 PASC patients confirmed by a positive antigen or PCR test with no prior history of heart or lung disease. PASC patients were compared to 766 non-COVID patients with unspecified dyspnea without known diagnosis of cardiac or pulmonary disease. ANOVA according to the general linear model and Pearson’s Chi square were used for the bivariate analysis of the quantitative and categorical variables, respectively. Analyses were controlled for age, sex, and beta blocker use as appropriate. Both HR and SBP at rest and peak exercise were significantly different between groups, although the absolute differences were small. Results: Compared with the control group, the post-COVID patients were younger (mean age 47 SD ±14.9 years versus 50.5 SD ±10.1 years) and more likely to be female (70.1% (54 of 77) vs 57.6% (441 of 766)). Although there were many significant differences in the CPET results, the most outstanding were a lower FAC (73 SD ±19.4% vs 85.2 SD ±20.8%) and peak VO2 (22 SD ±6.4 ml/kg/min vs 25.8 SD ±7.37 ml/kg/min) in the study group (p<.0001). Also, CNS changes during CPET were reported at higher rates (19.5% (15 of 77) vs 11.4% (87 of 766)) while dyspnea at lower rates (55.8% (43 of 77) vs 65.7% (503 of 766)) in post-COVID patients (p=0.02). When adjusting for age and sex, weight was significantly higher in the study group (p=0.03) although the absolute difference was modest and BMI remained not significant. PFTs did not suggest any pulmonary abnormalities. Conclusions: We identified a high rate of severe exercise limitation among long COVID patients. Young women may be at higher risk for these complications. Pre-exercise PFTs and absence of objective respiratory limitation during CPET argue against a primary pulmonary cause of the observed limitations, though evaluation of cardiac, autonomic, and muscular impairment is pending. Further studies are warranted to untangle the physiologic abnormalities responsible for these observations.

Objective We studied the effect of a lifestyle therapy program using the resources already available in a cardiac rehabilitation setting for patients at risk for metabolic syndrome (MetS). Methods We created a six-week cardiometabolic program (CMP) using facilities and resources of a cardiac rehabilitation setting. The CMP included a minimum of 6 once-a-week 60 min sessions consisting of exercise training and nutrition instruction, in addition to 6 once-a-week 60 min group behavioral modification classes following the LEARN program. We also assessed the outcomes in 239 patients (pts) who had at either obesity or hyperglycemia: 58 pts had enrolled and completed the CMP, 58 pts had signed up for the CMP but either never attended or dropped out early (Control 1) and had follow-up data, and 123 pts had not signed up for the CMP but had been seen in the outpatient preventive cardiology practice at the Mayo Clinic (Control 2). We compared changes in components of the MetS from baseline to six weeks (for the CMP group) and at 6 months for all pts. Results Of 187 people who signed up for the CMP, only 62 completed the program and from those, 58 gave authorization to use their clinical data in research. Of the 125 that never attended or dropped out early, 58 had follow-up data. Clinical characteristics of the CMP, Control 1, and Control 2 groups and improvement in each of the outcome measures are shown in the Table. In the CMP group, there was a significant improvement at 6 weeks in waist circumference, weight, diastolic blood pressure and total cholesterol. At 6 months the fasting glucose had also significantly improved. In contrast, improvements in Control 1 and Control 2 were modest at best. See Table. When comparing the 6 month changes in the CMP and Control 1, those in the CMP had more pronounced weight loss (-4.5±5 kg vs -0.14±6 kg, p<0.001); decrease in systolic blood pressure (-1.1±17 mmHg vs +9.6±20 mmHg, p=0.004); and decrease in diastolic blood pressure (-4.6±11 mmHg vs +3.4±15 mmHg, p=0.0017). Similarly, comparing CMP vs Control 2, a significantly greater drop in body weight (-4.5±5 kg vs -0.9±3 kg, p<0.001) and in diastolic blood pressure (-4.6±11 mmHg vs -0.7±9 mmHg, p=0.0202) was noted in the CMP. The change in the number of MetS components per patient dropped significantly, favoring the CMP group compared with the control groups. Conclusion A lifestyle therapy program for patients at risk for MetS can be implemented using existing resources of a cardiac rehabilitation program, although enrollment and completion rates are low. Such a program, however, is effective at improving cardiometabolic outcomes in individuals at risk for MetS.

Introduction: Patients undergoing cardiac rehabilitation (CR) exhibit various degrees of illness severity and high prevalence of chronic conditions (CC). Cardiorespiratory fitness (CRF) is a key predictor of outcomes in patients with cardiovascular disease. Participation in CR is associated with increased CRF, reduced future cardiovascular events, and mortality. Peak oxygen uptake (VO 2 ) is the gold-standard method to evaluate CRF; however, the burden of multimorbidity and its impact on CRF improvement has not been extensively studied. Methods: We included 618 patients who were ≥ 18 years old and underwent cardiopulmonary exercise testing prior to and after CR at Mayo Clinic. Using the Rochester Epidemiology Project records- linkage system, we assessed the prevalence of 18 CC defined by the US Department of Health and Human Services. To evaluate changes in peak VO 2 in patients with multimorbidity (categorized as ≥6 CC), we created logistic regression models adjusting for age, sex, and baseline peak VO 2 . Results: Mean age was 61.5 ± 11.0 years and 75.5% were male. Most patients (81.2%) attended ≥18 CR sessions. Half (50.4%) of patients had at least 6 CC (median 6; range 0-13). Overall, peak VO 2 at baseline was 20.7 ± 6.3 mL/kg per min and the percent change in peak VO 2 following CR was 11.4% ± 21.6%, Figure 1A . Multimorbidity was associated with lower improvement in peak VO 2 following CR compared to patients with <6 CC (7.5% vs 11.4%, p=0.0001). Furthermore, across categories of CRF improvement (i.e., 1%, 5%, and 10% percent change in peak VO 2 ) lower multimorbidity was associated with a 1.5-2-fold increase in CRF when compared to those with higher multimorbidity (≥6 CC), Figure 1B . Conclusions: Patients entering CR have a high multimorbidity burden. Our results suggest that multimorbidity in CR patients attenuates improvement in peak VO 2 . Individualized interventions should focus on managing and reducing multimorbidity to minimize the negative impact on CRF improvement.