Peak Metabolic Equivalents Research Articles

Use of the ECG-Controlled Six-Minute Walk Test to Assess Exercise Capacity: a Comparative Cohort Study

INTRODUCTION. In clinical practice, stress tests are carried out to draw up an individual patient rehabilitation plan, assess tolerance and optimize the load, and evaluate its clinical effectiveness. The Six-minute walk test (6MWT), in the presence of contraindications to the bicycle ergometer test or the impossibility of performing it, is a tool for assessing the response of the cardiovascular and respiratory systems to the load being performed. There is no description in the literature of the relationship between the distance traveled during 6MWT and the peak metabolic equivalent (MET) assessed during the bicycle ergometer test. AIM. Study the relationship between 6MWT indicators and the results of bicycle ergometer test in patients who have suffered a myocardial infarction. MATERIALS AND METHODS. During the examination, 56 patients underwent a symptom limited bicycle ergometer test and 6MWT, the peak MET and the distance traveled during 6MWT, as well as changes in the ECG during both tests were assessed. RESULTS AND DISCUSSION. The average values of maximum heart rate during the bicycle ergometer test and ECG-controlled 6MWT did not differ significantly. The distance in meters during 6MWT and the power of the exercise performed during bicycle ergometer test in MET have a significant relationship, which indicates the comparability of the data from these tests as a criterion of exercise tolerance. CONCLUSION. The use of 6MWT and bicycle ergometer test allows us to assess various aspects of cardiorespiratory function and physical fitness in patients undergoing a cardiac rehabilitation program. Further study of the possibility of using ECG-controlled 6MWT in the early stages of rehabilitation is necessary to create the most effective and safe physical training for patients who have suffered a myocardial infarction.

Exploring the characteristics changes of cardiopulmonary exercise testing in patients with acute coronary syndrome after PCI before and during the COVID-19 pandemic

Objective: To investigate the changes in cardiopulmonary exercise testing (CPET) characteristics before and after the outbreak of COVID-19 in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI). Methods: This is a cross-sectional study that included ACS patients who underwent PCI at the General Hospital of the Northern Theater Command from July 2018 to February 2023. Based on the timeline of the COVID-19 pandemic, patients were divided into two groups: the pre-pandemic group and the during-pandemic group, with January 2020 as the dividing line. Clinical data were collected from both groups, and a comparative analysis was performed on their postoperative CPET outcomes, including peak oxygen uptake (peak VO2), peak metabolic equivalents (peak MET), and other indicators. Weber's classification was used to assess cardiac function. In addition, the 7-tiem generalized anxiety disorder scale (GAD-7) and the patient health questionnaire-9 (PHQ-9) were used to assess the patients' psychological anxiety and depression states, respectively. Multivariate logistic regression was used to analyze the influencing factors of CPET after PCI. Results: A total of 4 310 post-PCI ACS patients were included, with an average age of (58.7±9.1) years, and 3 464 (80.37%) were male. There were 1 698 patients in the pre-pandemic group and 2 612 patients in the during-pandemic group. The main indicator of the CPET, peak VO2 (15.04±3.93) ml·min-1·kg-1 in the during-pandemic group, was lower than that in the pre-pandemic group (15.52±3.68) ml·min-1·kg-1, and the difference was statistically significant (P<0.001). Multivariate logistic regression analysis showed that advanced age, female gender, high body mass index, elevated high-sensitivity C-reactive protein, reduced high-density lipoprotein cholesterol, smoking history, history of myocardial infarction, more severe ACS classification, and mild to moderate degree of depression were related to poor cardiopulmonary outcomes (P<0.05). Conclusion: The COVID-19 pandemic had a negative impact on the cardiopulmonary outcomes of ACS patients after PCI. Reduced physical activity, and increased psychological stress should be given consideration and attention regarding their impact on patients' cardiopulmonary function.

Impact of cardiac rehabilitation exercise frequency on exercise capacity in patients with coronary artery disease: a retrospective study

ABSTRACT Cardiac rehabilitation (CR) significantly improves cardiovascular outcomes in patients with coronary artery disease (CAD). International guidelines vary in the minimum recommended frequency of supervised exercise from 1 to 3 sessions per week. This is the first study in the Middle East and North African regions assessing the impact of 2 versus 3 days/week of supervised exercise on peak exercise capacity in patients with CAD. Single-center retrospective cohort study involving 362 patients enrolled in the only CR center in the State of Qatar. Only high-quality data was included by strict evaluation of compliance to the exercise intervention. Fifty patients who underwent a symptom-limited exercise test before and after CR were included (31 patients on 2 days/week, 19 on 3 days/week). No significant differences were observed in baseline characteristics between groups. Exercise intervention differed significantly between groups in exercise training frequency (2 days/week: 1.97 ± 0.2 vs. 3 days/week: 2.7 ± 0.3; p < 0.00). Peak exercise capacity as peak metabolic equivalents of task (MET) significantly increased in both groups (2 days/week: Pre 8.3 ± 2.4 vs. Post 9.4 ± 2.9, p-value 0.00; 3 days/week: Pre 7.4 ± 1.6 vs. Post 8.4 ± 2.0, p-value 0.00). No significant difference was observed between groups for change in Peak Exercise Capacity (2 days/week 1.1 ± 1.1 vs. 3 days/week 1.0 ± 0.9, p = 0.87). When the total number of exercise sessions is equal, supervised exercise frequencies of 2 and 3 days/week may significantly and equally improve peak exercise capacity in patients with CAD.

O95 HYPERTENSIVE RESPONSE TO EXERCISE RELATIVE-TO-FITNESS AND LEFT VENTRICULAR HYPERTROPHY ARE ASSOCIATED WITH INCREASED RISK OF CARDIOVASCULAR EVENTS: EVIDENCE FROM THE EXERCISE STRESS TEST COLLABORATION (EXERTION) STUDY

Background. A hypertensive response to exercise (HRE) is associated with a high prevalence of left ventricular hypertrophy (LVH), both being related to an increased risk of cardiovascular disease (CVD). However, these associations may be influenced by aerobic capacity (fitness). This study aimed to determine if an HRE considered relative-to-fitness and LVH are associated with increased risk for CVD events. Methods. Records for 4,307 individuals (aged 58.6±12.7 years, 52.0% male) who underwent exercise stress echocardiography were linked to administrative health datasets (hospital and emergency admissions) to ascertain CVD events (n=458, mean follow-up, 44.8±25.9 months). LVH presence/absence (LVH+/LVH-) was defined as LV mass index adjusted for body surface area around a cut point of ≥115 g/m2 for men and ≥95 g/m2 for women. HRE presence/absence (HRE+/HRE-) relative-to-fitness was defined as peak systolic blood pressure (SBP) divided by peak metabolic equivalents around a cut point of ≥90th percentile. Survival analysis using Cox-proportional hazard regression was used to compare CVD event rates across the four groups defined by the combinations of HRE+/HRE- with LVH+/LVH-, adjusted for age, sex, pre-exercise SBP, and CVD history. Results. Compared to the reference group (HRE-/LVH-), there was a stepwise increase in CVD event rate (Figure 1) across the following groups: HRE+/LVH- [Adjusted HR(95%CI), 1.34(1.02-1.76)], HRE-/LVH+ [Adjusted HR(95%CI), 2.1(1.6-3.76)], HRE+/LVH+ [Adjusted HR(95%CI), 2.55(1.64-3.97)]. Conclusion. Individuals with both HRE considered relative-to-fitness and LVH are at the highest risk of CVD events, greater than either clinical presentation alone. These results emphasise the need to address an HRE and low fitness in people with LVH to improve CVD risk management.

Impact of Cardiorespiratory Fitness on COVID-19–Related Outcomes: The Exercise Testing and Health Outcomes Study (ETHOS)

ObjectiveTo assess the association between cardiorespiratory fitness (CRF) and COVID-19–related health outcomes including mortality, hospitalization, and mechanical ventilation. Patients and MethodsIn a retrospective analysis of 750,302 patients included in the Exercise Testing and Health Outcomes Study, we identified 23,140 who had a positive result on COVID-19 testing between March 2020 and September 2021 and underwent a maximal exercise test in the Veterans Affairs Health Care System between October 1, 1999 to September 3, 2020. The association between CRF and risk for severe COVID-19 outcomes, including mortality, hospitalization due to COVID-19, and need for intubation was assessed after adjustment for 15 covariates. Patients were stratified into 5 age-specific CRF categories (Least-Fit, Low-Fit, Moderate-Fit, Fit, and High-Fit), based on peak metabolic equivalents achieved. ResultsDuring a median of follow-up of 100 days, 1643 of the 23,140 patients (7.1%) died, 4995 (21.6%) were hospitalized, and 927 (4.0%) required intubation for COVID-19–related reasons. When compared with the Least-Fit patients (referent), the Low-Fit, Moderate-Fit, Fit, and High-Fit patients had hazard ratios for mortality of 0.82 (95% CI, 0.72 to 0.93), 0.73 (95% CI, 0.63 to 0.86), 0.61 (95% CI, 0.53 to 0.72), and 0.54 (95% CI, 0.45 to 0.65), respectively. Patients who were more fit also had substantially lower need for hospital admissions and intubation. Similar patterns were observed for elderly patients and subgroups with comorbidities including hypertension, diabetes, cardiovascular disease, and chronic kidney disease; for each of these conditions, those in the High-Fit category had mortality rates that were roughly half those in the Low-Fit category. ConclusionAmong patients positive for COVID-19, higher CRF had a favorable impact on survival, need for hospitalization, and need for intubation regardless of age, body mass index, or the presence of comorbidities.

Stroke Incidence in Patients With Hypertension According to Cardiorespiratory Fitness.

Hypertension and physical inactivity are risk factors for stroke. The effect of cardiorespiratory fitness (CRF) on stroke risk in patients with hypertension has not been assessed. We evaluated stroke incidence in patients with hypertension according to CRF and changes in CRF. We included 483 379 patients with hypertension (mean age±SD; 59.4±9.0 years) and no evidence of unstable cardiovascular disease as indicated by a standardized exercise treadmill test. Patients were assigned to 5 age- and sex-specific CRF categories based on peak metabolic equivalents achieved at the initial exercise treadmill test and in 4 categories based on metabolic equivalent changes over time (n=110 576). Multivariable Cox models, adjusted for age, and comorbidities were used to estimate hazard ratios and 95% CIs for stroke risk. During a median follow-up of 10.6 (interquartile range, 6.6-14.6) years, 15 925 patients developed stroke with an average yearly rate of 3.1 events/1000 person-years. Stroke risk declined progressively with higher CRF and was 55% lower for the High-fit individuals (hazard ratio, 0.45 [95% CI, 0.42-0.48]) compared with the Least-fit. Similar associations were observed across the race, sex, and age spectra. Poor CRF was the strongest predictor of stroke risk of all comorbidities studied (hazard ratio, 2.24 [95% CI, 2.10-2.40]). Changes in CRF reflected inverse and proportional changes in stroke risk. Poor CRF carried a greater risk than any of the cardiac risk factors in patients with hypertension, regardless of age, race, or sex. The lower stroke risk associated with improved CRF suggests that increasing physical activity, even later in life, may reduce stroke risk.

The impact of cardiorespiratory fitness on COVID-19 related outcomes: the ETHOS Study

Abstract Background Comorbidities such as cardiovascular disease, diabetes, obesity and hypertension are associated with more severe COVID-19 outcomes, but the relative impact of cardiorespiratory fitness (CRF) on outcomes in COVID-positive patients is largely unknown. Objective To assess the association between objectively measured CRF and COVID-19-related health outcomes including mortality, hospitalization, and mechanical ventilation in non-COVID vaccinated patients. Design, Setting and Participants. Retrospective analysis of 750,302 subjects (23,140 [mean age 65.8±12.0 years] with a positive COVID-19 test between March 2020 and September 2021) who underwent a maximal exercise test between 1999 and 2020. Main Outcomes and Measures. Association between all-cause mortality, hospitalization due to COVID-19, and need for intubation with risk for severe COVID-19 outcomes after adjustment for 15 covariates. Subjects were stratified into five age-specific CRF categories (Least-fit, Low-fit, Moderate-fit, Fit and High Fit), based on peak metabolic equivalents achieved. Results During a median of follow-up of 100 days, 1,643 (7.1%) patients died, 4,995 (21.6%) were hospitalized, and 927 (4.0%) required intubation for COVID-19 related reasons. When compared to the Least-Fit subjects (referent), the Low-Fit, Moderately-Fit, Fit, and High-Fit subjects had hazard ratios for mortality of 0.82 (95% CI; 0.72-0.93), 0.73 (95% CI; 0.63-0.86), 0.61 (95% CI; 0.53-0.72), and 0.54 (95% CI; 0.45-0.65), respectively (Figure). Subjects who were more fit also had significantly lower need for hospital admissions and intubation. Similar patterns were observed for elderly subjects and subgroups with comorbidities including hypertension, diabetes, cardiovascular disease, and chronic kidney disease; for each of these conditions, those in the High-Fit category had mortality rates that were roughly half those in the Low-Fit category. Conclusion Among subjects positive for COVID-19, higher CRF had a favorable impact on survival, need for hospitalization, and need for intubation regardless of age, BMI, or the presence of comorbidities.

CHRONIC KIDNEY DISEASE INCIDENCE AND CARDIORESPIRATORY FITNESS ASSOCIATION IN HYPERTENSIVE PATIENTS

Objective: Chronic hypertension (HTN) is considered a strong risk factor for developing chronic kidney disease (CKD). Increased cardiorespiratory fitness (CRF) is associated with lower CKD risk. However, the CRF-CKD association in patients with HTN has not been assessed. Thus, we examined the the association between CRF and the risk of developing CKD in hypertensive patients. Design and method: Hypertensive individuals (n=471,579; age 63.0+8.8 years) with normal kidney function prior to HTN and no evidence of ischemia indicated by a maximal standardized exercise treadmill test (ETT). The cohort was part of the ETHOS study (n=750,302). We established five CRF categories based on age-and-gender-adjusted peak metabolic equivalents (METs) achieved: Least-Fit (4.5±1.2 METs; n=106,955); Low-Fit Fit (6.9±1.1 METs; n=122,612); Moderate-Fit (8.3±1.2 METs; n=91,995); Fit (10.3±1.2 METs; n=111,472); and High-Fit (13.2±1.6 METs; n=38,545). CKD risk across CRF categories was assessed by multivariable Cox Regression analysis, adjusted for age, blood pressure, body mass index (BMI), alcohol abuse, traditional risk factors, and medications. Results: During 6,146,773.0 person-years of follow-up (median 12.9 years), 58,701 individuals developed CKD (9.6 events/1,000 person-years of observation). The CRF-CKD association was inverse, independent of comorbidities and graded. The risk of developing CKD was 9% lower for each 1-MET increase (Hazard Ratio [HR] 0.91; 95% confidence interval [CI] 0.90-0.93). When CKD risk was assessed across CRF categories using the Least-fit category as the referent, the risk was 20% lower (HR 0.80; CI 0.78-0.81, p&lt;0.001) for those in the Low-fit category (6.9±1.1 METs). The risk declined progressively with increased CRF and was 49% lower for those in the highest CRF category (HR 0.49; CI 0.47-0.51, p&lt;0.001). Similar findings were observed in the subgroup of hypertensive patients with diabetes mellitus (n=192,966). Conclusions: We noted an inverse and dose-response association between CRF and CKD incidence. The risk was attenuated significantly beyond a MET level of 6.9±1.1 METs, suggesting that moderate increases in exercise capacity lowers the risk of developing CKD in hypertensive patients.

Cardiorespiratory fitness and risk of heart failure with preserved ejection fraction.

Preventive strategies for heart failure with preserved ejection fraction (HFpEF) include pharmacotherapies and lifestyle modifications. However, the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized exercise treadmill test (ETT) and the risk of HFpEF has not been evaluated. Thus, we evaluated the association between CRF and HFpEF incidence. We assessed CRF in US Veterans (624 551 men; mean age 61.2 ± 9.7 years and 43 179 women; mean age 55.0 ± 8.9 years) by a standardized ETT performed between 1999 and 2020 across US Veterans Affairs Medical Centers. All had no evidence of heart failure or myocardial infarction prior to completion of the ETT. We assigned participants to one of five age- and gender-specific CRF categories (quintiles) based on peak metabolic equivalents (METs) achieved during the ETT and four categories based on CRF changes in those with two ETT evaluations (n = 139 434) ≥1.0 year apart. During a median follow-up of 10.1 years (interquartile range 6.0-14.3 years), providing 6 879 229 person-years, there were 16 493 HFpEF events with an average annual rate of 2.4 events per 1000 person-years. The adjusted risk of HFpEF decreased across CRF categories as CRF increased, independent of comorbidities. For fit individuals (≥10.5 METs) the hazard ratio (HR) was 0.48 (95% confidence interval [CI] 0.46-0.51) compared with least fit (≤4.9 METs; referent). Being unfit carried the highest risk (HR 2.88, 95% CI 2.67-3.11) of any other comorbidity. The risk of unfit individuals who became fit was 37% lower (HR 0.63, 95% CI 0.57-0.71), compared to those who remained unfit. Higher CRF levels are independently associated with lower HFpEF in a dose-response manner. Changes in CRF reflected proportional changes in HFpEF risk, suggesting that the HFpEF risk was modulated by CRF.

The Association between Cardiorespiratory Fitness and the Risk of Breast Cancer in Women.

Studies have shown an inverse association between the risk of breast cancer in women and physical activity. However, information on the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized test and the risk of developing breast cancer is limited. To examine the CRF-breast cancer risk association in healthy females. This retrospective study was derived from the Exercise Testing and Health Outcomes Study cohort ( n = 750,302). Female participants ( n = 44,463; mean age ± SD; 55.1 ± 8.9 yr) who completed an exercise treadmill test evaluation (Bruce protocol) at the Veterans Affairs Medical Centers nationwide from 1999 to 2020 were studied. The cohort was stratified into four age-specific CRF categories (Least-fit, Low-fit, Moderate-fit, and Fit), based on the peak METs achieved during the exercise treadmill test. During 438,613 person-years of observation, 994 women developed breast cancer. After controlling for covariates, the risk of breast cancer was inversely related to exercise capacity. For each 1-MET increase in CRF, the risk of cancer was 7% lower (HR, 0.93; 95% CI, 0.90-0.95; P < 0.001). When risk was assessed across CRF categories with the Least-fit group as the referent, the risk was 18% lower for Low-fit women (HR, 0.82; 95% CI, 0.70-0.96; P = 0.013), 31% for Moderate-fit (HR, 0.69; 95% CI, 0.58-0.82; P < 0.001), and 40% for Fit (HR, 0.60; 95% CI, 0.47-0.75; P < 0.001). We observed an inverse and graded association between CRF and breast cancer risk in women. Thus, encouraging women to improve CRF may help attenuate the risk of developing breast cancer.

Abstract 14518: Interactive Effects of Statins, Obesity, and Cardiorespiratory Fitness in Type 2 Diabetes Mellitus Incidence

Introduction: Statin therapy and obesity are associated with increased risk of developing type 2 diabetes mellitus (T2DM). Conversely, cardiorespiratory fitness (CRF) is inversely related to T2DM incidence. The interaction between statin therapy, obesity, and CRF has not been addressed. Hypothesis: Obesity and statins will be associated with increased risk of T2DM, while CRF will mitigate this increased risk. Methods: From the ETHOS cohort, we identified 570, 054 patients (age 60.7±10.1 years) with no T2DM. All completed a standardized exercise treadmill test (ETT) with no evidence of ischemia. Subsequently, 322,805 (56.6%) were treated with statins for at least 8 months (mean 9.5±5.9 years) and 247,249 were not. Participants were classified based on body mass index (BMI) as normal weight (BMI&lt;25.0 kg/m 2 ), overweight (BMI 25.0-29.9 kg/m 2 ), Obese-I (BMI 30.0-34.9 kg/m2), and Obese-II (BMI ≥35.0 kg/m 2 ). We established five CRF categories based on age-specific quintiles of peak metabolic equivalents achieved: Least-Fit (n=95,071); Low-Fit (n=133,404); Moderate-Fit (n=110,973); Fit (n=158,004) and High-Fit (n=72,602). Adjusted Cox proportional hazards models were constructed to evaluate the association between BMI, statin therapy and T2DM risk, and the interaction with CRF status. Results: During the follow-up period (median 10.3 years), 44,662 developed T2DM (7.4 events/1,000 person-years of observation). The risk of developing T2DM was 44% higher in those treated with statins [Hazard Ratio (HR) 1.44; 95% confidence interval (CI) 1.41-1.48)] compared to those not on statin therapy. The risk increased progressively with higher BMI levels and was nearly 3 times higher for those in the Obese-II category (HR 2.96, CI 2.85-3.06). When T2DM risk was assessed across CRF categories within BMI groups, we noted a progressive decline in T2DM risk with increased CRF regardless of statin therapy or BMI status. The adjusted risk was approximately 25% to 40% lower for those in the two highest CRF categories. Conclusions: Statin therapy and obesity were associated with increased risk of developing T2DM. This risk was mitigated significantly with increased CRF regardless of BMI status.

Progression to Insulin Therapy in Patients With Type 2 Diabetes According to Cardiorespiratory Fitness, Body Mass Index, and Statin Therapy

ObjectiveTo evaluate the association between statin therapy, cardiorespiratory fitness (CRF), body mass index (BMI), and progression to insulin therapy in type 2 diabetes mellitus (T2DM). MethodsParticipants were patients with T2DM (mean age, 62.7±8.4 years; men, 178,992; women, 8360) not treated with insulin, with no evidence of uncontrolled cardiovascular disease, who completed an exercise treadmill test between October 1, 1999, and September 3, 2020. Of these, 158,578 were treated with statins and 28,774 were not. We established 5 age-specific CRF categories according to peak metabolic equivalents of task achieved during an exercise treadmill test. ResultsDuring a median follow-up period of 9.0 years, 51,182 patients progressed to insulin therapy with an average annual incidence rate of 28.4 events/1000 person-years. The adjusted progression rate was 27% higher in statin-treated patients (hazard ratio [HR], 1.27; 95% CI, 1.24 to 1.31), related directly to BMI and inversely related to CRF. A progressively higher rate was noted in statin-treated vs non–statin-treated patients within all BMI categories, ranging from 23% for normal weight to 90% for those with BMI of 35 kg/m2 and higher. The statin-CRF interaction revealed 43% higher rate in the least-fit statin-treated patients (HR, 1.43; 95% CI, 1.35 to 1.51) and a progressive decline with increased CRF to 30% lower risk in highly fit statin-treated patients (HR, 0.70; 95% CI, 0.66 to 0.75). ConclusionIn patients with T2DM, the statin-related progression to insulin therapy was associated with relatively low CRF and high BMI levels. The progression rate was mitigated by increased CRF regardless of BMI. Clinicians should foster regular exercise for patients with T2DM to enhance CRF and to lessen the rate of progression to insulin therapy.

ATRIAL FIBRILLATION AND MORTALITY RISK IN HYPERTENSIVE PATIENTS ACCORDING TO CARDIORESPIRATORY FITNESS

Objective: Atrial fibrillation (AF) is associated with increased risk of mortality. Epidemiologic evidence strongly supports an inverse and graded association between cardiorespiratory fitness (CRF) and mortality risk. The impact of CRF status on mortality risk in hypertensive patients with AF has not been assessed. The aim of the study was to evaluate the association between CRF and mortality risk in hypertensive patients with AF. Design and method: We identified 24,171 hypertensive patients (mean age 67.5±9.0 yrs), with documented AF who completed an exercise treadmill test (ETT) between years 1999 to 2020, with no evidence of ischemia. We established 5 fitness categories (quintiles) based on age-specific peak metabolic equivalents (METs) achieved: Least-fit (4.0±1.1 METs; n = 8,857); Low-fit (6.4±1.1 METs; n = 6,103); Moderate-fit (7.8±1.1 METs; n = 4,256); Fit (10.0±0.9 METs; n = 3,803) and High-fit (12.6±1.6 METs; n = 1,152). We used multivariable Cox proportional hazard models to estimate hazard ratios (HR) and 95% confidence intervals [CI] for mortality across CRF categories. The models were adjusted for age race, gender, resting blood pressure, comorbidities, and medications. Results: During follow-up (median = 8.8 years; 224,138 person-years), 10,499 individuals died (46.8 events per 1,000 person-years). The risk for stroke was 14% lower for each 1-MET increase in exercise capacity (HR = 0.86, CI: 0.85-0.87; p&lt;0.001). When considering CRF categories, mortality risk was 27% lower for the Least-Fit individuals (HR = 0.73; CI: 0.70-0.77) and declined progressively with increased CRF to approximately 45% t0 60% for Moderate-fit and Fit, and 67% (HR = 0.33; CI: 0.29-0.37) for High-Fit individuals. Conclusions: Increased CRF was inversely related to mortality in hypertensive patients with AF. The association was independent of comorbidities and graded.

COVID-19 AND MORTALITY IN HYPERTENSIVE PATIENTS ACCORDING TO CARDIORESPIRATORY FITNESS

Objective: COVID-19 mortality risk increases with the presence of underlying comorbidities, including hypertension. Epidemiologic evidence also suggests an inverse association between self-reported physical activity and COVID-19 cases and deaths. However, no information exists regarding the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized exercise treadmill test (ETT) and mortality in hypertensive patients. We assessed the hypothesis that CRF is inversely and independently associated with COVID-19 mortality risk in non-vaccinated hypertensive patients Design and method: From 2020 to 2021, we identified 17,358 hypertensive patients (mean age: 60.3 ± 8.2 years) with a normal response to an exercise tolerance test (ETT), prior to COVID-19. We established five CRF categories based on age-stratified quintiles of peak metabolic equivalents (MET) achieved: Least-Fit (4.7 ± 1.2 METs; n = 3,486); Low-Fit (7.1 ± 1.3; n = 4,616); Moderate-Fit (8.4 ± 1.3 METs; n = 3,320); Fit (10.3 ± 0.9 METs; n = 4,084); and High-Fit (12.8 ± 1.6 METs; n = 1,852). Multivariable Cox proportional hazard models were constructed to estimate hazard ratios (HR) and 95% confidence intervals [CI] for mortality across CRF categories. The models were adjusted for age, gender, race, comorbidities, medications, hospitalization, intubation, and time elapsed between ETT and COVID-19. The Least-Fit category was used as the reference group. Results: Results: During the follow-up of 100 days, 1,853 individuals died (10.7%). The risk for death was 7% lower for each 1-MET increase in exercise capacity (HR = 0.93, CI: 0.92-0.95; p &lt; 0.001). The risk across fitness categories declined progressively with increased CRF and was 26% lower for the Least-Fit individuals (HR = 0.74; CI: 0.66 - 0.84), approximately 30% to 40% lower for Moderate-Fit and Fit, and 50% lower (HR = 0.50; CI: 0.41 - 0.62; p &lt; 0.001) for High-Fit patients. Conclusions: Increased CRF was inversely related to COVID-19 mortality risk in hypertensive patients. The association was graded and independent of comorbidities.

CARDIORESPIRATORY FITNESS AND STROKE INCIDENCE IN HYPERTENSIVE PATIENTS

Objective: Stroke incidence is significantly higher in hypertensive patients compared to normotensive subjects. Cardiorespiratory fitness (CRF) is associated with a more favorable cardiovascular health. The CRF-stroke incidence association in hypertensive patients has not been fully explored. Thus, the objective of the current study was to evaluate the association between CRF assessed objectively by a standardized exercise test, and stroke incidence in hypertensive patients. Design and method: From 1999 to 2020, we identified 460,172 hypertensive patients (mean age: 63.1 ± 8.7 years) with a normal response to an exercise treadmill test (ETT) and no prior history of stroke. We established five CRF categories based on age-stratified quintiles of peak metabolic equivalents (MET) achieved: Least-Fit (4.5 ± 1.2 METs; n = 106,620); Low-Fit (6.9 ± 1.1; n = 120,327); Moderate-Fit (8.3 ± 1.2 METs; n = 89,748); Fit (10.3 ± 0.9 METs; n = 107,323); and High-Fit (13.1 ± 1.6 METs; n = 36,154). A multivariable Cox proportional hazards model was constructed to estimate hazard ratios (HR) and 95% confidence intervals [CI] for incidence of stroke across CRF categories. The model was adjusted for age, resting blood pressure, gender, race, coronary artery disease, smoking status, chronic kidney disease, atrial fibrillation, other cardiac risk factors, and medications. The Least-fit category was used as the reference group. Results: During follow-up (median = 10.6 years; 4,955,021 person-years), 11,868 individuals had a stroke (2.4 events per 1,000 person-years). The risk for stroke was 8% lower for each 1-MET increase in exercise capacity (HR = 0.92, CI: 0.91 - 0.93; p &lt; 0.001). The risk across fitness categories, declined progressively with increased CRF and was by 15% for the Least-Fit individuals (HR = 0.85; CI: 0.81 - 0.89), approximately 30% to 40% for Moderate-fit and Fit individuals, and 45% lower (HR = 0.55; CI: 0.50 - 0.60; p &lt; 0.001) for High-Fit individuals. Conclusions: Increased CRF was inversely related to stroke incidence in hypertensive patients. The association was independent and graded. These finding support the concept that health care professional should encourage patients to engage in habitual physical activity of moderate intensity and progressively aim to meet the physical activity guidelines proposed by authorities.

Validation of the 25 level modified shuttle test in children with cystic fibrosis.

To evaluate the validity and reliability of the modified shuttle 25-level test (MST-25) in children with cystic fibrosis (CF). A prospective single center study in clinically stable children with CF. Participants undertook two testing conditions on different days: (1) 2xMST-25 tests; (2) cardiopulmonary exercise test (CPET). Test order was randomized. Nadir oxygen saturation (SpO2 ), peak heart rate (HR), breathlessness (modified Borg), rate of perceived exertion (RPE), energy expenditure (EE) and metabolic equivalents (MET) from the MST-25 and CPET were compared to assess validity, while outcomes from 2xMST-25 tests were compared for reliability. CPET was performed using breath-by-breath analysis and EE from the MST-25 obtained using the SenseWear Armband. Strong correlations were found between MST-25 distance and peak oxygen uptake, peak work and minute ventilation on CPET (all r > 0.7, p < 0.01). Moderate correlations were found between MST-25 distance and CPET for METs (r = 0.5) and HR (r = 0.6). Weak associations between tests were evident for nadir SpO2 (r = 0.1), modified Borg (rs = 0.2) and RPE (rs = 0.2). Test-retest reliability was excellent for MST-25 distance (ICC 0.91), peak EE (ICC 0.99) and peak METs (ICC 0.90). Good reliability was achieved for HR (ICC 0.84) and modified Borg score (ICC 0.77), while moderate reliability for nadir SpO2 (ICC 0.64) and RPE (ICC 0.68) was observed. The MST-25 is a valid and reliable field test for the assessment of exercise capacity in children with CF. The MST-25 can be used to accurately monitor exercise capacity and prescribe exercise training, particularly when CPET is not available.

An evaluation of the role of the exercise training dose for changes in exercise capacity following a standard cardiac rehabilitation program

BackgroundTo retrospectively characterize and compare the dose of exercise training (ET) within a large cohort of patients demonstrating different levels of improvement in exercise capacity following a cardiac rehabilitation (CR) program. MethodsA total of 2310 patients who completed a 12-week, center-based, guidelines-informed CR program between January 2018 and December 2019 were included in the analysis. Peak metabolic equivalents (METpeak) were determined pre- and post-CR during which total duration (ET time) and intensity [percent of heart rate peak (%HRpeak)] of supervised ET were also obtained. Training responsiveness was quantified on the basis of changes in METpeak from pre- to post-CR. A cluster analysis was performed to identity clusters demonstrating discrete levels of responsiveness (i.e., negative, low, moderate, high, and very-high). These were compared for several baseline and ET-derived variables which were also included in a multivariable linear regression model. ResultsAt pre-CR, baseline METpeak was progressively lower with greater training responsiveness (F(4,2305) = 44.2, P < 0.01, η2p = 0.71). Likewise, average training duration (F(4,2305) = 10.7 P < 0.01, η2p = 0.02) and %HRpeak (F(4,2305) = 25.1 P < 0.01, η2p = 0.042) quantified during onsite ET sessions were progressively greater with greater training responsiveness. The multivariable linear regression model confirmed that baseline METpeak, training duration and intensity during ET, BMI, and age (P < 0.001) were significant predictors of METpeak post-CR. ConclusionsAlong with baseline METpeak, delta BMI, and age, the dose of ET (i.e., training duration and intensity) predicts METpeak at the conclusion of CR. A re-evaluation of current approaches for exercise intensity prescription is recommended to extend the benefits of completing CR to all patients.

Facemask Use During Graded Exercise Testing in the COVID-19 Pandemic: Minimal Concern

ABSTRACT Background Graded exercise testing (GXT) is a fundamental component of the diagnosis/treatment of patients with suspected/known cardiovascular disease (CVD). Amid the current pandemic, patients must wear a facemask during GXTs, yet the impact of facemask use on peak values from a GXT has not been evaluated in individuals at increased risk of developing CVD. The objective is to examine potential differences in peak values obtained from a GXT performed under facemask versus no facemask conditions among adults at increased risk for CVD. Methods Using a randomized, crossover study design, 16 adults at moderate risk for developing CVD completed 2 trials (facemask versus no facemask). Peak speed, grade, heart rate (HR), and rating of perceived exertion were recorded during a Modified Bruce Treadmill GXT for each trial. Peak speed and grade were used to estimate peak oxygen consumption (Vo2peak) and peak metabolic equivalents of task (Vo2peak/3.5). Results Total exercise time (17:10 ± 2:04 versus 15:58 ± 1:51 minutes, P = 0.0005), peak HR (170 ± 11 versus 164 ± 11 b·min−1, P = 0.01), estimated Vo2peak (42.3 ± 8.9 versus 36.8 ± 6.6 mL·kg−1·min−1, P = 0.005), and peak metabolic equivalents of task (12.2 ± 2.6 versus 10.5 ± 1.9, P = 0.005) were higher during the no facemask versus the facemask trial. Peak rating of perceived exertion was similar between trials (18.1 ± 1.3 versus 18.3 ± 1.2, P = 0.84). Conclusion Facemask use had a significant but modest clinical impact on hemodynamic responses during a GXT among moderate risk adults.

Effects of Mavacamten on Measures of Cardiopulmonary Exercise Testing Beyond Peak Oxygen Consumption

Mavacamten, a cardiac myosin inhibitor, improved peak oxygen uptake (pVO2) in patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM) in the EXPLORER-HCM study. However, the full extent of mavacamten's effects on exercise performance remains unclear. To investigate the effect of mavacamten on exercise physiology using cardiopulmonary exercise testing (CPET). Exploratory analyses of the data from the EXPLORER-HCM study, a randomized, double-blind, placebo-controlled, phase 3 trial that was conducted in 68 cardiovascular centers in 13 countries. In total, 251 patients with symptomatic obstructive HCM were enrolled. Patients were randomly assigned in a 1:1 ratio to mavacamten or placebo. The following prespecified exploratory cardiovascular and performance parameters were assessed with a standardized treadmill or bicycle ergometer test protocol at baseline and week 30: carbon dioxide output (VCO2), minute ventilation (VE), peak VE/VCO2 ratio, ventilatory efficiency (VE/VCO2 slope), peak respiratory exchange ratio (RER), peak circulatory power, ventilatory power, ventilatory threshold, peak metabolic equivalents (METs), peak exercise time, partial pressure of end-tidal carbon dioxide (PETCO2), and VO2/workload slope. Two hundred fifty-one patients were enrolled. The mean (SD) age was 58.5 (11.9) years and 59% of patients were male. There were significant improvements with mavacamten vs placebo in the following peak-exercise CPET parameters: peak VE/VCO2 ratio (least squares [LS] mean difference, -2.2; 95% CI, -3.05 to -1.26; P < .001), peak METs (LS mean difference, 0.4; 95% CI, 0.17-0.60; P < .001), peak circulatory power (LS mean difference, 372.9 mL/kg/min × mm Hg; 95% CI, 153.12-592.61; P = .001), and peak PETCO2 (LS mean difference, 2.0 mm Hg; 95% CI, 1.12-2.79; P < .001). Mavacamten also improved peak exercise time compared with placebo (LS mean difference, 0.7 minutes; 95% CI, 0.13-1.24; P = .02). There was a significant improvement in nonpeak-exercise CPET parameters, such as VE/VCO2 slope (LS mean difference, -2.6; 95% CI, -3.58 to -1.52; P < .001) and ventilatory power (LS mean difference, 0.6 mm Hg; 95% CI, 0.29-0.90; P < .001) favoring mavacamten vs placebo. Mavacamten improved a range of CPET parameters beyond pVO2, indicating consistent and broad benefits on maximal exercise capacity. Although improvements in peak-exercise CPET parameters are clinically meaningful, the favorable effects of mavacamten on submaximal exertional tolerance provide further insights into the beneficial impact of mavacamten in patients with obstructive HCM. ClinicalTrials.gov Identifier: NCT03470545.

Hybrid and Traditional Cardiac Rehabilitation in a Rural Area: A RETROSPECTIVE STUDY.

Cardiac rehabilitation is a prescribed exercise intervention that reduces cardiovascular mortality, secondary events, and hospitalizations. Hybrid cardiac rehabilitation (HBCR) is an alternative method that overcomes barriers to participation, such as travel distance and transportation issues. To date, comparisons of HBCR and traditional cardiac rehabilitation (TCR) are limited to randomized controlled trials, which may influence outcomes due to supervision associated with clinical research. Coincidental to the COVID-19 pandemic, we investigated HBCR effectiveness (peak metabolic equivalents [peak METs]), resting heart rate (RHR), resting systolic (SBP) and diastolic blood pressure (DBP), body mass index (BMI), and depression outcomes (Patient Health Questionnaire-9 [PHQ-9]). Via retrospective analysis, TCR and HBCR were examined during the COVID-19 pandemic (October 1, 2020, and March 31, 2022). Key dependent variables were quantified at baseline (pre) and discharge (post). Completion was determined by participation in 18 monitored TCR exercise sessions and four monitored HBCR exercise sessions. Peak METs increased at post-TCR and HBCR ( P < .001); however, TCR resulted in greater improvements ( P = .034). The PHQ-9 scores were decreased in all groups ( P < .001), while post-SBP and BMI did not improve (SBP: P = .185, BMI: P = .355). Post-DBP and RHR increased (DBP: P = .003, RHR: P = .032), although associations between intervention and program completion were not observed ( P = .172). Peak METs and depression metric outcomes (PHQ-9) improved with TCR and HBCR. Improvements in exercise capacity were greater with TCR; however, HBCR did not produce inferior results by comparison, an outcome that may have been essential during the first 18 mo of the COVID-19 pandemic.