Bonikowske, Amanda R.

Introduction: The COVID-19 pandemic imposed significant constraints to delivery of cardiac rehabilitation (CR) with many programs relying on delivery of home-based cardiac rehabilitation (HBCR). We sought to compare the effects of HBCR vs conventional center-based CR (CBCR) on clinical metrics, health-related quality of life, and modifiable risk factors in CR patients. Methods: Retrospective cohort study comparing 511 HBCR patients (March 2020-April 2021; COVID-19 pandemic) and 765 age and sex matched CBCR patients (Jan 2018-Jan2020; immediately pre-pandemic) from the Mayo Clinic Health System. We assessed changes in clinical outcomes before and after CR. HBCR included 12 sessions (one in-person assessment + weekly education and exercise monitoring phone/video calls). Conventional CBCR included 36 sessions (3 sessions per week for 12 weeks). Continuous data were described as mean±SD, and comparisons of change between groups were assessed with linear regression adjusting for baseline value, in complete cases. Results: HBCR and CBCR patients were 65±14 yrs old (68% male) and 65±14 yrs old (67% male) respectively. HBCR patients demonstrated greater improvement in exercise days/week whereas CBCR patients had greater improvement in exercise min/day. HBCR patients had greater improvement in blood glucose with a trend towards greater improvement in non-HDL cholesterol. Both groups demonstrated similar improvement on nutrition, depression, health-related quality of life surveys and total, LDL and HDL cholesterol, as well as HbA1c between the groups. Conclusions: Collecting clinical metrics during the COVID-19 pandemic proved challenging due to the initial closure of out-patient services. For patients in whom data was captured, HBCR appears to be similarly effective at improving several intermediate outcomes compared to CBCR. HBCR may be an effective alternative for improving clinical outcomes in patients who are unable to participate in CBCR.

Introduction: Breathing efficiency (V E /VCO 2 slope or nadir) predicts mortality in heart failure (HF). The usual pattern of V E /VCO 2 vs. exercise intensity is a characteristic “shallow bowl” configuration allowing estimate of a V E vs. VCO 2 slope both in normal controls (C) and HF patients. Slope or nadir in HF is generally > 33 vs. 25-30 in C. This pattern of V E /VCO 2 may not be true for other CV diseases. Objective: Compare V E /VCO 2 versus exercise time curves in patients with history of chronic thromboembolic pulmonary hypertension type 4 (PHT4) to HF and C referred for dyspnea on exertion. Methods: We identified 40 consecutive cases of PHT4 versus 40 HF and 40 C over the same age range retrospectively selected from our cardiopulmonary exercise test (CPX) database. V E /VCO 2 was plotted against exercise time (minutes of exercise ≈ METs), and groups were compared statistically for V E /VCO 2 and peak VO 2 by ANOVA followed with Tukey test, with significance set at P < .05. Results: Figure shows higher V E /VCO 2 in PHT4 vs. HF and C with a different pattern vs. exercise intensity. In severe cases (example shown) V E /VCO 2 may increase continuously without plateau reaching peak values > 80. There was statistically significant difference between peak VO 2 between C group vs HF and PHT4, but not among HF and PHT4, although V E /VCO 2 was significant different among the three groups. Age and sex was not different among them. Conclusion: V E /VCO 2 was elevated in PHT4 compared to HF and C. We interpret continuously increasing V E /VCO 2 as a marker of progressively worsening ventilation: perfusion mismatch. Interpretation of V E /VCO 2 in PHT4 cannot be based simply on nadir or slope as in HF, but a plot of the data should be visually examined to gain full understanding of the ventilatory abnormality.

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.

Background: To identify factors that increase the specificity of the treadmill exercise test (TMET), and develop a novel scoring system which accounts for functional capacity to aid in determining the need for further testing. Methods: We retrospectively evaluated the electronic health records of 600 patients who had positive TMET results and follow-up stress echocardiography from 1-January-2004, through 31-December-2016. Correlations between clinical and aerobic variables and multivessel disease (MVD) were determined. Duke Treadmill Score (DTS) was calculated and compared with a novel scoring system titled the Intermediate-High-Workload Treadmill Score (IHWTS) that used variables associated with MVD. Results: In total, 124 of 600 patients (21%) had coronary catheterization, and 51 of these patients (41%) had MVD. Mean (SD) DTS was –2.10 (6.3) among patients with MVD vs –0.16 (5) among patients without MVD (p = 0.06). Mean (SD) functional aerobic capacity (FAC) was 76% (20%) among patients with MVD vs 90% (21%) among patients without MVD (p < 0.001). Mean (SD) metabolic equivalent (MET) was 7 (2) among patients with MVD vs 8 (2) among patients without MVD (p = 0.002). Only 6 (12%) of patients with MVD achieved 9 MET or greater on TMET. DTS less than 4 did not distinguish between patients with and without MVD (p = 0.67). Age, hypertension and FAC were independently associated with MVD (all p < 0.05). Conclusions: Our novel scoring system IHWTS utilized age, hypertension, and FAC appeared comparable to DTS to risk-stratify patients regardless of baseline symptoms. Clinical parameters such as hypertension along with exercise functional capacity should be considered when evaluating a positive TMET result in patients that achieve an intermediate-high workload >5 Metabolic Equivalents (METs).

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.

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.

Introduction: Multimorbidity is associated with physical disability, increased health care utilization, reduced quality of life, and mortality. Whereas most literature has focused on the co-occurrence of somatic conditions, we aim to (i) establish the prevalence of combined somatic and mental health multimorbidity (SMM) in cardiac rehabilitation (CR) patients, and (ii) determine the most prevalent co-occurrence of cardio-metabolic conditions (CMC) with other somatic or mental health conditions in CR patients. Methods: Using the Rochester Epidemiology Project records-linkage system, we identified residents of Southern MN and Western WI who attended (≥1) CR sessions from 1995 to 2019. The prevalence of 18 chronic conditions defined by the US Department of Health and Human Services was electronically extracted. Heat maps were created to assess the pairwise prevalence of cardio-metabolic (CMC; n=6) with mental (n=5) and other somatic (n=7) chronic conditions (Table 1) . Results: We included 13,056 patients; 68.5% were male. Patients were 65.5±12.5 years old with 44.7% ≤65 years old. Median number of conditions was 7 (Range 0-18) with 52.6% of patients having ≥7 conditions. Hyperlipidemia (89.3%), hypertension (79.5%), and arrhythmias (72.4%) were the most prevalent CMC. The prevalence of combined SMM (≥2 conditions) was 44.9% and was higher in those <65 years ( p <.0001). Depression (26.8%) and anxiety (24.7%) were the most common mental conditions involved in SMM and frequently co-occurred with CMC. Among other prevalent somatic conditions, arthritis (51.7%), chronic obstructive pulmonary disease (33.5%), and cancer (29.3%) co-occurred with CMC (Figure 1). Conclusions: Half of patients in CR have ≥7 chronic conditions. Somatic and mental health multimorbidity (SMM) is highly prevalent and is more frequent in those younger than 65 years old. Our results highlight the critical need to better understand the clinical burden of SMM in patients undergoing CR.

Introduction: The presence of chronic somatic and mental health conditions is complex and challenging for patients and the health care system due to the health deficit accumulation, worsening outcomes, and increased health care utilization. While previous studies on multimorbidity have focused on somatic chronic conditions, we aim to assess the relation between somatic, mental, and combined somatic-mental multimorbidity (SMM) and impact on Major Adverse Cardiac Events (MACE) in patients enrolled in phase II outpatient cardiac rehabilitation (CR). Methods: Using the Rochester Epidemiology Project records-linkage system, we identified patients from Olmsted County, Minnesota who were 18 years old and attended (≥1) CR sessions at Mayo Clinic Rochester. The prevalence of 18 (somatic=13; mental=5) chronic conditions defined by the US Department of Health and Human Services was ascertained electronically. Results: We included 618 patients; 24.4% were female. Patients were 61.5±11.0 years old with 38.0% ≥65 years old. Overall median number of chronic conditions was 6 (Range 0-13) with 98.8% of patients having ≥2 conditions. The prevalence of combined SMM was 44.6%. Mean follow-up was 7.3± 4.5 years, 147 (23.7%) patients had MACE (number): acute coronary syndrome (46), percutaneous coronary intervention (33), heart failure (16), stroke (8), coronary artery bypass grafting (4), ventricular arrhythmias (4), or death (65). Risk of MACE in patients with SMM was significantly higher compared to patients with only somatic conditions (HR: 1.62, 95% CI: 1.14-2.30, p=0.01 ), Figure 1. The association remained significant after adjustment for age and sex ( p=0.006 ). Conclusions: Our results show that somatic-mental multimorbidity (SMM) in CR patients is highly prevalent and imposes a higher risk of MACE compared with patients who have only somatic conditions highlighting the importance of individualized assessment and care plans to reduce adverse events and mortality.

Introduction: Coronary artery disease (CAD) has been associated with cognitive decline. Cardiac rehabilitation (CR) is a class 1A recommendation for patients with CAD as it reduces future cardiac events and mortality. However, the impact of CR on incidence of mild cognitive impairment (MCI) and dementia has not been extensively studied. We investigated the association of CAD on incidence of MCI and dementia; and whether CR attendance reduces incidence of MCI and dementia in patients with CAD Methods: The Mayo Clinic Study of Aging (MCSA), a prospective, population-based cohort was probed for this study. At baseline and every 15-months thereafter, subjects were evaluated for MCI and dementia using a standardized protocol. Data on CR participation were collected via record linkage to the Rochester Epidemiology Project. To evaluate association with incident MCI or dementia, cox proportional hazard models were used and adjusted for age, sex, and clinical predictors of cognitive decline. Participants with MCI at baseline were excluded for MCI analysis and adjusted for in dementia analysis. Results: We included 5960 MCSA participants (female: 50%; age: 70±13). Of those, 1934 participants (32%) had CAD and 702 (12%) had MCI at baseline. Mean follow-up was 3.9±3.7yrs, with 760 incident cases of MCI (13%) and 290 cases of dementia (5%). CAD was a significant predictor of MCI and dementia, although after adjustment for other clinical predictors, CAD was only associated with MCI incidence ( Table 1, Figure ). Incidence of dementia was reduced in CAD patients who had a greater attendance at CR when adjusted for other predictors of cognitive decline ( Table 2 ). Attendance at CR did not reduce incidence of MCI ( Table 2 ). Conclusions: CAD was a significant predictor of MCI and dementia. In patients with CAD, a higher attendance of CR was associated with reduced incidence of dementia but not MCI. Specific CR programming and outcome targets may be needed to prevent MCI in patients with CAD.