Physical Activity and Relationship to Physical Function, Quality of Life, and Cognitive Function in Older Patients with Acute Decompensated Heart Failure

Abstract

Background:

Volitional physical activity level is predictive of a variety of health outcomes, but has not been examined in patients recently hospitalized for acute decompensated HF (ADHF).

Methods:

Ten to 14 days after index hospitalization for ADHF, 93 participants wore a wrist-mounted triaxial accelerometer (ActiGraph GT3X+) to objectively quantify sedentary behavior, light physical activity, and moderate-to-vigorous physical activity. Levels were compared to two groups of age-matched NHANES participants: healthy and chronic, stable HF. The relationship between physical activity levels and physical function [Short Physical Performance Battery (SPPB)], HF-specific quality-of-life (QOL) [Kansas City Cardiomyopathy Questionnaire (KCCQ)], and cognition [Montreal Cognitive Assessment (MOCA)] were examined.

Results:

ADHF participants accumulated a median 1008 (IQR 896,1109) mins of sedentary time, 88 (57,139) mins of light physical activity, and 10 (6,25) mins of moderate-to-vigorous physical activity per day. Sedentary time, light physical activity, or moderate-to-vigorous activity did not differ by sex or EF subtype. ADHF participants spent only 9% of awake time non-sedentary, compared to 34% and 27% for healthy adults and adults with chronic, stable HF, respectively. Among ADHF participants, SPPB, KCCQ, and MOCA scores did not differ among quartiles of total physical activity.

Conclusions:

Older patients recently hospitalized for ADHF have very low levels of physical activity and high levels of sedentary time, both of which may be potential targets for interventions in this high-risk population. Physical activity level was not significantly associated with objectively measured physical function, QOL, or cognition, suggesting that this measure provides independent information regarding the patient experience of living with HF.

Registration:

NCT02196038, https://clinicaltrials.gov/ct2/show/NCT02196038

INTRODUCTION

The US Physical Activity Guidelines recommend 150 to 300 minutes per week of moderate-to-vigorous physical activity for health benefits independent of age; however, the majority of Americans do not meet that goal.^1,2 Low physical activity level is well-recognized as a major risk factor for cardiovascular disease morbidity and mortality,^3,4 including the development of heart failure (HF).⁵ Similarly, evidence suggests that prolonged sedentary time, independent of physical activity levels, also has negative health impacts in a variety of populations.^6–8

In adults living with chronic stable HF, regardless of HF subtype [i.e., preserved ejection fraction (HFpEF) or HF with reduced ejection fraction (HFrEF)], physical activity levels are typically low and often accompanied by exercise intolerance and reduced quality of life (QOL).^9–12 Previous studies have shown that physical activity, exercise capacity, physical function, and QOL, while all similarly reduced in chronic stable HF, have only weak to modest correlations with each other.^10,13 Further, improvements in exercise capacity, physical function, and QOL in response to exercise training lack significant associations with physical activity.^14–17 Taken together, these data suggest that physical activity assessment may provide independent unique and important information of the patient experience of living with HF.

In contrast to adults with chronic stable HF receiving care on an outpatient basis, adults hospitalized for acute decompensated HF (ADHF) are typically older and have much more severely impaired physical and cognitive function, higher rates of frailty, and worse QOL.^18–21 To our knowledge, physical activity has not previously been objectively measured in frail, older adults who were discharged directly home from the hospital after ADHF. Previous assessments of physical activity in AHDF have been self-reported through questionnaire,²² which are prone to error recall, overestimate moderate to vigorous physical activity, and underestimate sedentary time.^23,24 As a result, the levels of physical activity in this population and relationships to physical function, QOL, and cognitive function in ADHF are unknown.

The purpose of this study was to objectively assess the amount and intensity of physical activity and sedentary time and to examine the associations of physical activity with physical function, QOL, and cognitive function in a cohort of older adults recently hospitalized for ADHF.

METHODS

Study Population

Participants were included from a randomized controlled trial investigating a physical rehabilitation intervention for older patients hospitalized for ADHF (REHAB-HF).²⁰ The trial design and protocol have been previously described in detail elsewhere.^25,26 Briefly, participants were patients aged ≥60 years who were hospitalized ≥24 hours for ADHF, regardless of ejection fraction (EF). Participants were required to be independent with activities of daily living and ambulatory with or without a gait aid prior to admission as well as expected to be discharged home. Key exclusion criteria included acute myocardial infarction, end-stage HF, eGFR ≤20ml/min/1.73m² or requiring dialysis, already participating in formal cardiac rehabilitation, and inability to participate due to dementia, stroke, or other disorder. The protocol was approved by the Institutional Review Board at each of the 7 clinical sites and all patients provided informed consent.

After stabilization of ADHF, participants underwent baseline testing and were randomized to the Rehabilitation Intervention or Attention Control. Randomization was stratified by EF category and clinical site. Upon discharge, the intervention included 3 supervised facility-based sessions per week that begun after the home and built environment assessment. The assessment occurred within one week of discharge and guided development of the home exercise program, which supplemented the facility-based sessions. Participants were instructed in low-intensity walking at their usual pace on non-facility days, gradually increasing toward a goal of 30 minutes. Participants in Attention Control did not receive any specific exercise recommendations. All participants received usual care as prescribed by their healthcare provider, which could include physical therapy or other rehabilitation services.

All consecutively enrolled participants after February 2016 wore an accelerometer (ActiGraph GT3X+) continuously during the trial. There were 210 participants enrolled in the main trial during this time who were eligible for accelerometer data collection. Of these, 34 (16%) refused to wear the device; 39 (19%) had no baseline data file (e.g., did not return or lost the device, were non-compliant, or technical errors); 21 (10%) did not have valid data in the file (see data validation below); 23 (11%) did not have data within the first two weeks after index hospital discharge. Ultimately, 93 participants with at least 1 valid day of accelerometer data within the first two weeks after hospital discharge were included in this analysis.

Accelerometer-Assessed Physical Activity

Physical activity and sedentary time were assessed using the ActiGraph GT3X+ (Pensacola, FL), a triaxial accelerometer, worn on the non-dominant wrist. Participants were instructed to begin wear as soon as discharge from the index hospitalization, and wear for 24 hours/day, 7 days/week. Participants were allowed to remove the monitor for showering, bathing, and swimming.²⁷

Accelerometer data were collected at a sample rate of 30 Hz and processed using r package GGIR (version 2.4.0). Wear time was calculated using standard algorithms.²⁸ Valid wear days were defined as >16 hours per day of wear time. Accelerometer data were used to derive daily averages and quartiles of total wear time, sleep duration, sedentary time, light intensity activity time (<3 METs), and moderate-to-vigorous intensity activity time (≥3 METs). Due to a lack of well-accepted, generalizable, and validated intensity thresholds for wrist-worn ActiGraph accelerometers using the ActiGraph proprietary summary metric of counts and a lack of accepted, validated method to calculate the number of steps from the wrist in an ActiGraph monitor, physical activity intensity was classified using standard, validated cut-points for wrist-worn devices from Hildebrand et al.,²⁹ derived from raw accelerations in three orthogonal planes to estimate energy expenditure.^30,31 These cut points were validated using this specific device at the wrist placement in a controlled, laboratory setting across a standardize protocol including multiple activities of various intensity using indirect calorimetry assessed energy expenditure as a reference (r = 0.86), This method and these intensity thresholds were chosen a priori and employs an open-source framework using the raw accelerations to increase generalizability across different monitor types and wear locations.

Baseline physical activity was defined as up to 2 weeks following hospital discharge. Participants who began the intervention within this period were included in the analyses. Intervention began as soon as possible following hospital discharge and after the home and built environment assessment (median: 10 days, median intervention sessions attended: 2). All analyses were conducted as a single group adjusted for randomization to account for differences between trial arms. All analyses and data processing were conducted by statistician blinded to treatment group (ES).

Physical Function, Quality of Life, and Cognitive Function Assessment

Physical function, QOL, and cognitive function were assessed in the hospital after initial treatment and stabilization for ADHF and prior to discharge home. All assessments were conducted by trained personnel with standardized procedures. Physical function was assessed using the Short Physical Performance Battery (SPPB).³² The SPPB is a standardized, reproducible, global physical function measure that has been validated in older and frail populations, and is predictive of a range of clinical outcomes.^33–35 It consists of 3 components: a standing balance test, a 4-meter walk test, and a repeated chair stand test. Each component is scored on a scale of 0–4 with a total score of 0–12, with higher scores indicating better physical function. QOL was assessed using the Kansas City Cardiomyopathy Questionnaire (KCCQ) overall score, on a scale of 0–100 with a higher score indicating better health status.³⁶ The other KCCQ subscale scores (physical limitations, self-efficacy, social limitations, and total symptoms) were also examined as secondary outcomes. Cognitive function was assessed using the Montreal Cognitive Assessment.³⁷

National Health and Nutrition Examination Survey: an External Comparison Cohort

Accelerometry was collected as part of the National Health and Nutrition Examination Survey (NHANES), a US population-based cohort, in 2003–2004 and 2005–2006 using the ActiGraph model 7164 accelerometer. Study procedures and data analysis protocols have been extensively described elsewhere.^27,38 In brief, adults identified in the outpatient setting wore an accelerometer on their hip during waking hours for 7 days. Physical activity intensity was classified using standard cut-points.³⁹ Adults with at least one valid day (≥10 hours of wear) and aged ≥60 years were included in these analyses. The age range was chosen to be comparable to the current study. In addition, a subpopulation of NHANES participants with prevalent, stable, chronic HF (without recent hospitalization) was also used to compare to the current study. Demographics of the included NHANES participants are listed in Supplement 1.

Statistical Analyses

Participant demographics, comorbidities, physical activity, and sleep were described as the number (percent), mean (standard deviation), or median (interquartile range) based on variable type and statistical distribution. To compare physical activity levels by sex and heart failure subtype, the median (interquartile range) of minutes per week within each intensity category (sedentary time, light activity, and moderate-to-vigorous activity) were compared using Wilcoxon test (alpha=0.05).

To examine the association of total physical activity (mean minutes per day) with physical function, QOL, and cognitive function scatterplots were constructed and fitted with a loess curve for all participants and by sex and HF subtype. Next, mean (95% CI) SPPB, QOL, other KCCQ subscales, and MOCA scores were calculated within subgroup specific quartiles for total physical activity. Differences in SPPB, QOL, other KCCQ subscales, and MOCA among the four quartiles were testing using an ANOVA framework adjusting for multiple comparisons with a False Discovery Rate. Due to physical activity data being collected post-randomization, additional sensitivity analyses to evaluate differences in physical activity levels and outcomes by randomized group assignment were also conducted to assess for potential differences due to intervention exposure.

To compare the REHAB-HF participants to an external, validation cohort, the percent time of the waking day spent in sedentary behavior, light intensity activity, and moderate-to-vigorous activity were graphically compared to the two NHANES cohorts.

RESULTS

Overall, ADHF participants (N=93) were aged 72.2±8.5 years, 50% female, primarily identified as White and Black/African American races (53% White, 40% Black/African American, 4% American Indian/Alaska Native, and 3% multiple races), 57% had HFpEF, and an average of 5.3 comorbidities. Participant demographics and medical history were generally similar across physical activity quartiles (Table 1). ADHF participants had severely reduced physical function, as indicated by mean SPPB score of 6.3 (95% confidence interval: 5.8, 6.8), where a score <10 indicates high risk for physical disability. QOL was also poor with mean overall KCCQ score of 38 (35, 42), where a score of 50 to 75 indicates fair to good and >75 for good to excellent. The average MOCA score was 22.3 (21.6, 23.1), indicating, on average, at least mild cognitive impairment. Overall, the baseline characteristics (demographics and functional scores) of this sample were similar to that of the overall REHAB-HF trial.

Table 1.

Baseline ADHF Participant Characteristics, Comorbidities, Physical Activity, and Sleep by Total Physical Activity Quartile

	All Participants
Characteristics	N=93
Age (years)	72.2 (8.5)
Female	65 (50%)
American Indian/Alaska Native	5 (4%)
Asian	0 (0%)
Black/African American	52 (40%)
Native Hawaiian/Pacific Islander	0 (0%)
White	68 (53%)
Multiple Races	4 (3%)
BMI (kg/m2)	32.8 (9.1)
EF < 45%	39 (42%)
NYHA Class 2	14 (15%)
NYHA Class 3	54 (58%)
NYHA Class 4	21 (23%)
Hospitalized in past 6 months	36 (39%)
Hospitalized for heart failure	6 (15%)
Randomized to Intervention	52 (56%)
Comorbidities
Hypertension	86 (92%)
Hyperlipidemia	58 (62%)
Diabetes	54 (58%)
Atrial fibrillation	47 (51%)
CAD (MI, PCI, CABG)	8 (9%)
Chronic obstructive pulmonary disease	28 (30%)
Chronic Kidney Disease	27 (29%)
Stroke	10 (11%)
Arthritis	49 (53%)
Depression	22 (24%)
Total comorbidities	5.3 (2.0)
Physical Activity and Sleep
Sedentary time (min/d)	1008 (896,1109)
Light physical activity (min/d)	88 (57, 139)
Moderate-to-Vigorous Activity (min/d)	10 (6, 25)
Sleep Duration (h/d)	5.4 (3.6, 6.5)

Data presented as mean (SD) or N (%). Physical activity and sleep parameters presented as median (IQR).

Overall, ADHF participants accumulated a median 1008 (IQR 896, 1109) mins of sedentary time, 88 (57, 139) mins of light physical activity, and 10 (6, 25) mins of moderate-to-vigorous physical activity per day. There were no statistically significant differences in time spent in sedentary behavior, light intensity activity, or moderate-to-vigorous physical activity among ADHF participants by sex or HF subtype (Table 2). In sensitivity analyses, there were no significant differences by randomization (data not shown).

Table 2.

Physical Activity by Sex and Heart Failure Subtype

Subgroup	Level	Sedentary Time (min/d)	Light Activity (min/d)	Moderate-to-Vigorous Activity (min/d)
All	All	1008 (896, 1109)	88 (57,139)	10 (6, 25)
Sex	Male	998 (894, 1143)	85 (56, 118)	10 (6, 24)
	Female	1011 (903, 1075)	94 (57, 160)	10 (6, 25)
	p-value	0.51	0.29	0.82
Heart Failure Subtype	EF < 45%	1037 (947, 1126)	81 (54, 128)	9 (4, 22)
	EF >= 45%	993 (877, 1093)	94 (58, 147)	13 (8, 25)
	p-value	0.09	0.24	0.28

Data presented as median (IQR). P-values represent a test of differences between sex and HF subtype subgroups. After adjustment for multiple comparisons, no significance between subgroups.

On average, ADHF participants spent 91% of their waking day in sedentary behavior, 8% in light intensity activity, and <1% in moderate-to-vigorous intensity activity (Figure 1). Compared to NHANES healthy adults aged ≥60 years, ADHF participants spent more time in sedentary behavior (ADHF 91% vs. NHANES healthy 66%) and less time in light intensity activity (ADHF 8% vs. NHANES-healthy 33%). Additionally, compared to NHANES adults aged ≥60 years with prevalent, stable, chronic heart failure, ADHF participants spent less time active (non-sedentary) (ADHF 9% vs. NHANES-HF 27%) and more time sedentary (ADHF 91% vs. NHANES-HF 73%).

Figure 1.

Physical function, quality of life, and cognitive function by total physical activity per day. Abbreviations: SPPB: Short Physical Performance Battery; MOCA: Montreal Cognitive Assessment.

There were no statistically significant differences in SPPB, QOL score,other KCCQ subscale scores, or cognitive function among the four physical activity quartiles among all participants and by sex or HF subtype, Table 3 & Supplemental Table 2). We observed this general lack of difference in physical function, QOL, and cognitive function when examining total physical activity continuously in the scatterplots as demonstrated by a relatively flat trend line or a lack of noticeable pattern between activity and the performance scores (Figure 2).

Table 3.

Physical function, QOL, and cognition by Physical Activity Quartile Among Older Hospitalized Patients with Acute Decompensated Heart Failure at Baseline

		All	Sex		Heart Failure Subtype
Outcome	Total PA Quartile		Male	Female	EF < 45%	EF >= 45%
SPPB Score	High	5.7 (4.5, 7.0)	7.3 (5.4, 9.1)	4.8 (3.6, 5.9)	7.5 (5.7, 9.3)	5.1 (3.7, 6.6)
	Medium-high	7.7 (6.6, 8.7)	8.3 (7.1, 9.5)	6.7 (4.9, 8.6)	7.4 (6.3, 8.6)	7.2 (5.6, 8.9)
	Medium-low	6.0 (5.0, 7.1)	6.9 (5.4, 8.4)	5.4 (4.2, 6.5)	6.4 (4.9, 8.0)	5.9 (4.4, 7.4)
	Low	5.2 (4.2, 6.2)	6.0 (4.8, 7.3)	4.0 (2.6, 5.5)	5.0 (3.7, 7.3)	4.8 (3.5, 6.1)
	p-value	0.07	0.27	0.19	0.27	0.19
KCCQ Score	High	41.3 (30.2, 52.4)	36.8 (23.4, 50.2)	40.3 (25.0, 55.6)	53.3 (35.9, 70.8)	41.7 (27.9, 55.5)
	Medium-high	43.1 (33.3, 52.9)	42.4 (29.3, 55.54)	45.5 (28.3, 62.6)	31.5 (17.1, 45.8)	37.8 (26.2, 49.5)
	Medium-low	37.7 (29.0, 46.3)	36.8 (24.2, 49.4)	42.4 (28.4, 56.4)	45.8 (34.6, 57.1)	32.7 (20.0, 45.4)
	Low	33.0 (24.1, 41.9)	28.5 (17.6, 39.4)	38.2 (24.5, 51.9)	36.7 (24.2, 49.1)	32.7 (19.4, 46.1)
	p-value	0.84	0.84	0.92	0.83	0.91
MOCA Score	High	21.9 (20.6, 23.2)	23.8 (21.8, 25.9)	21.2 (19.2, 23.2)	22.0 (19.3, 24.7)	22.0 (20.6, 23.4)
	Medium-high	23.0 (21.7, 24.4)	22.3 (20.7, 23.8)	22.4 (20.6, 24.1)	23.2 (21.0, 25.4)	23.1 (21.4, 24.8)
	Medium-low	23.4 (21.9, 24.8)	23.6 (21.9, 25.2)	23.0 (20.7, 25.3)	22.4 (19.9, 24.9)	23.0 (21.0, 25.0)
	Low	20.8 (18.5, 23.1)	22.1 (19.6, 24.6)	19.8 (15.9, 23.8)	19.2 (14.7, 23.7)	22.7 (20.7, 24.7)
	p-value	0.65	0.65	0.65	0.65	0.83

Data are presented as mean (95% confidence interval). P-values represent a test of differences in means among total physical activity quartiles from ANOVA. After adjustment for multiple comparisons, no significance between quartiles or subgroups.

Figure 2.

Percent of waking day spent in sedentary behavior, light, and moderate-to-vigorous intensity physical activity among REHAB-HF and NHANES participants with and without heart failure.

DISCUSSION

This study assessed physical activity levels of older adults recently discharged from an acute hospitalization for ADHF, examined the relationship of those levels with measures of physical function, QOL, and cognitive function, and compared those levels with two cohorts of age-matched older adults who were healthy or had chronic stable HF. Among older adults who had an ADHF episode, physical activity levels were extremely low, spending only 10 minutes or <1% of their waking day in moderate-to-vigorous physical activity, and sedentary time was very high, spending only 9% of their waking day non-sedentary. Even in comparison to age-matched healthy and chronic stable HF cohorts, physical activity levels were dramatically lower and sedentary time higher. Despite broad and marked functional impairments, there were no significant relationships between physical activity levels and physical function, QOL, or cognitive function, indicating that each may represent distinct dimensions of functional performance. The lack of relationship was consistent across sex and heart failure subtypes.

Our findings extend prior literature by providing the first objective quantification of physical activity levels in older adults after acute ADHF hospitalization. Overall, REHAB-HF participants engaged in only 89 mins of total physical activity per day, ~9% of their waking day, and only 10 min of that was of moderate-to-vigorous intensity. This is well below the recommended level of at least 150 min/week of moderate intensity physical activity,¹ and is in stark contrast with age-matched NHANES adults who have chronic stable HF let alone those who are healthy. Only the group with the highest quartile of total physical activity approached the recommended levels of physical activity, with a median of 28 min/day of moderate-to-vigorous intensity physical activity; however, the vast majority (>75%) of participants had little to no moderate-to-vigorous intensity physical activity. These extremely low levels of physical activity are concerning, given that the participants in this study had achieved clinical stability, medication optimization, and were deemed able to be discharged to independent living conditions, often living alone (30%).⁴⁰ Based on the established link between low physical activity and risk of mortality and HF hospitalization in chronic stable HF,^11,41,42 persistently low physical activity levels, may pose an even greater health risk to patients who have most recently experienced an ADHF event. Further, the high degree of sedentary time (91% of waking day) is itself an independent risk factor for further worsening of cardiometabolic disease morbidity,^6,43–45 mortality,^46,47 and disability with loss of independence.⁴⁸

Our data contrast with the only other previous assessment of physical activity levels in ADHF. In the Exercise Joins Education: Combined Therapy to Improve Outcomes in Newly-discharged Heart Failure (EJECTION-HF) study, 44% of patients self-reported achieving 150-min/week of moderate-to-vigorous intensity physical activity in a similar period following discharge from the hospital.²² However, activity was assessed only using subjective self-report methods, which are prone to recall error and can lead to substantial overestimation of physical activity levels, unlike the accelerometer-assessed activity in REHAB-HF.^23,24 Previous studies in chronic stable HF using objectively measured activity parameters, as well as the NHANES cohort used for comparison in this study, have shown that HF patients have overall lower levels of physical activity, not achieving the recommended levels for adults to attain health benefits.^10,12 Importantly, the physical activity levels found in REHAB-HF were lower than those measured in NHANES chronic stable HF; lower levels of physical activity may reflect greater disease severity, more severe sarcopenia and frailty,⁴⁹ and higher symptom burden from recent ADHF.

This study also extends previous literature examining the relationships among physical activity, physical function, and QOL in ADHF. The lack of significant associations of objectively assessed activity levels with these dimensions of functional performance agree with previous studies in patients with chronic stable HFpEF and HFrEF. In chronic HF, there have been only modest correlations between measures of physical function, such as 6MWD and exercise capacity (peak VO₂), and physical activity measures.^10,14,50,51 Similarly, only modest correlation has been described between QOL and physical activity.^10,52 These data support that physical activity, physical function, and QOL capture independent and important information of the patient experience of HF symptomology and functional performance.

The lack of relationships between dimensions of functional performance is likely due in large part to the very low physical activity levels observed in this study. While there is some degree of relationship among physical activity, physical function, and QOL in chronic stable HF owing to a broader spectrum and variability of impairment in all three dimensions, in AHDF, physical activity levels were so low to the point of being virtually nonexistent that there may have been no ability to detect any relationships between physical activity and physical function and QOL. Similarly, sensitivity analyses examining the KCCQ subscales did not show statistically significant differences by physical activity quartile.

These findings have several potentially important clinical implications. First, patients who had a recent ADHF hospitalization do not achieve physical activity levels sufficient for attaining and maintaining health benefits, and have high levels of sedentary time, posing independent, additive risks for continued poor health, mortality, and disability. Therefore, strategies to increase levels of physical activity in these patients may be beneficial. However, these patients also had severe physical function impairments in the domains of mobility, balance, and strength; it is known that attempting to increase physical activity level before correcting these impairments places patients at high risk for injury and falls.^53,54 Thus, novel physical rehabilitation strategies addressing these multi-domain impairments may be needed to help these patients safely increase physical activity levels. Finally, physical activity, physical function, QOL, and cognitive function may represent distinct dimensions of patient-important functional performance and should be assessed separately in order to fully characterize functional deficits and better understand the patient experience of living with advanced HF.

This study has some limitations. While wrist-worn accelerometers are desirable due to better compliance among wearers, they can lead to the overestimation of physical activity measures, due to extraneous or overly limited movements of the arms. However, if the physical activity estimates observed in our study were indeed overestimated, this would amplify the findings of very low physical activity levels. In addition, wrist-worn accelerometers have been validated against indirect calorimetry, showing that estimates are highly correlated with energy expenditure (r = 0.86). It was not feasible to have the physical activity assessment occur simultaneously with assessment of physical function and QOL but the measurements were taken as closely as possible, usually within 10 days. While data from this study were part of a randomized trial, in sensitivity analyses, there were no statistical differences by randomization arm. Finally, although this study is a cross-sectional analysis, it provides keys insights into the multiple functional performance dimensions and deepens understanding of the patient experience of living with HF.

In conclusion, this study is the first to objectively measure physical activity patterns in older patients recently discharged for an ADHF hospitalization. Physical activity levels were very low, and sedentary time was high in comparison to an age-matched healthy cohort and chronic stable HF patients. Additionally, there was no relationship between physical activity and physical function, QOL, or cognitive function. These findings highlight the importance of physical activity assessment in patients with ADHF, the distinct information it adds to description of the patient experience with ADHF, and its potential importance as a therapeutic target for future intervention studies.