The role of maximal inspiratory pressure on functional performance in adults with heart failure.

BACKGROUND: Exercise intolerance is common among adults with heart failure (HF) and is a strong prognostic indicator. We examined maximal inspiratory pressure (MIP) as an indicator of maximal and submaximal exercise capacity in older HF patients. METHODS: Fifty-one patients age ≥ 50 years with HF underwent MIP testing via the PrO2 device. Peak oxygen uptake (VO2), 6 min walk distance (6MWD), 30 s sit-to-stand test (STS), gait speed (GS), grip strength and lower extremity muscle strength [one-repetition maximum (1RM)] were measured. Correlation and exploratory multiple regression analyses investigated relationships between MIP, left ventricular ejection fraction (LVEF), age, body mass index (BMI) and physical function. MIP was then stratified by median (64 cm H2O), and endpoints were compared between median groups. RESULTS: The median age was 69 years [interquartile range (IQR): 66-73], and the median LVEF was 36.5% (IQR: 30%-45%). Regression identified MIP as an independent predictor for grip strength, 6MWD, 1RM weight and 30 s STS after adjustment for age, BMI and LVEF. MIP greater than the median (n = 25) independently predicted and reflected greater peak VO2 [14.2 (12.8-18.1) vs. 11.5 (9.7-13.0) mL/kg/min; P = 0.0007] as well as 6MWD, 1RM, 30 s STS and GS (all P < 0.05). CONCLUSION: The analysis demonstrates that MIP is a novel biometric for exercise tolerance in adults with HF. Assessments of MIP are safe and convenient, with the potential to enhance routine HF surveillance and provide novel biometrics to guide HF therapeutics.

Modified Application of Cardiac Rehabilitation in Older Adults (MACRO) Trial: Protocol changes in a pragmatic multi-site randomized controlled trial in response to the COVID-19 pandemic.

BACKGROUND: Older adults are at higher risk for cardiovascular disease and functional decline, often leading to deterioration and dependency. Cardiac rehabilitation (CR) provides opportunity to improve clinical and functional recovery, yet participation in CR decreases with age. Modified Application of CR in Older Adults (MACRO) is a National Institute on Aging (NIA)-funded pragmatic trial that responds to this gap by aiming to increase enrollment of older adults into CR and improving functional outcomes. This article describes the methodology and novel features of the MACRO trial. METHODS: Randomized, controlled trial of a coaching intervention (MACRO-I) vs. usual care for older adults (age ≥ 70 years) eligible for CR after an incident cardiac hospitalization. MACRO-I incorporates innovations including holistic risk assessments, flexible CR format (i.e., helping patients to select a CR design that aligns with their personal risks and preferences), motivational prompts, nutritional emphasis, facilitated deprescription, enhanced education, and home visits. Key modifications were necessitated by the COVID-19 pandemic, including switching from a performance-based primary endpoint (Short Physical Performance Battery) to a patient-reported measure (Activity Measure for Post-Acute Care Computerized Adaptive Testing). Changes prompted by COVID-19 maintain the original intent of the trial and provide key methodologic advantages. CONCLUSIONS: MACRO is exploring a novel individualized coaching intervention to better enable older patients to participate in CR. Due to COVID-19 many aspects of the MACRO protocol required modification, but the primary objective of the trial is maintained and the updated protocol will more effectively achieve the original goals of the study.

Energy Expenditure During Acute Periods of Sitting, Standing, and Walking.

BACKGROUND: Identifying strategies to increase energy expenditure (EE) may help combat the harmful effects of sedentary behavior. This study examined EE during sitting, standing, and walking. METHODS: Participants (N = 74) were randomized to 2 of the following activities: sitting using a laptop computer (SIT-C), sitting watching television (SIT-T), standing watching television (STAND), and walking at a self-selected pace ≤3.0 (mph) (WALK). Each activity lasted 15 minutes with a 3-minute transition period between activities. The experimental conditions were: SIT-C to STAND (N = 18), SIT-T to WALK (N = 18), STAND to SIT-C (N = 20), and WALK to SIT-T (N = 18). EE was measured using indirect calorimetry. RESULTS: Based on the first activity performed, EE during WALK (55.92 ± 14.19 kcal) was significantly greater than SIT-C (19.63 ± 6.90 kcal), SIT-T (18.66 ± 4.01 kcal), and STAND (21.92 ± 5.08 kcal) (P < .001). Cumulative EE in SIT-T to WALK (74.50 ± 17.88 kcal) and WALK to SIT-T (82.72 ± 21.70 kcal) was significantly greater than EE in SIT-C to STAND (45.38 ± 14.78 kcal) and STAND to SIT-C (45.64 ± 9.69 kcal) (P < .001). CONCLUSION: Substituting periods of sitting or standing with walking significantly increases EE, but substituting periods of sitting with standing may not affect EE. Thus, the potential benefits of standing as opposed to sitting need further investigation beyond the role of EE.