Study on the correlation between fatigue, anxiety, and depression in patients with chronic heart failure

Abstract

BACKGROUND

Chronic heart failure (CHF) has a prolonged clinical course, and patients commonly experience fatigue. It remains unclear whether anxiety and depression exacerbate fatigue in patients with CHF.

AIM

To examine the correlation of fatigue status with anxiety and depression in patients with CHF and identify factors influencing fatigue.

METHODS

This observational study included 162 patients with CHF who visited the Department of Cardiology, Suzhou Ninth Hospital Affiliated to Soochow University, between May 2023 and May 2025. Fatigue was assessed using the Chinese version of the Multidimensional Fatigue Scale (MFI-20). Anxiety and depression were evaluated with the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS). Patient demographic and clinical data were collected using a general information questionnaire. Pearson correlation analysis was used to assess the relationship between fatigue, anxiety, and depression, while multiple linear regression analysis was conducted to identify factors influencing fatigue levels.

RESULTS

The mean MFI-20 fatigue score among the 162 patients with CHF was 70.76 ± 8.42. The mean SAS score was 58.87 ± 9.92, and the mean SDS score was 54.76 ± 7.91. Both SAS and SDS scores were positively correlated with MFI-20 scores (r = 0.479, r = 0.468; both P < 0.001). Multivariate regression analysis identified comorbidities [β = 0.903, 95% confidence interval (CI): 0.258-1.695], New York Heart Association functional class (III-IV) (β = 0.319, 95%CI: 0.269-0.743), poor sleep quality (β = 0.465, 95%CI: 0.294-0.948), anxiety (β = 1.728, 95%CI: 0.693-3.642), and depression (β = 1.649, 95%CI: 0.712-3.517) as significant factors influencing fatigue (P < 0.05).

CONCLUSION

Fatigue levels in patients with CHF were high and significantly influenced by comorbidities, advanced New York Heart Association functional class (III-IV), poor sleep quality, anxiety, and depression. Clinical interventions that address comorbid conditions, improve cardiac function, and provide sleep and psychological support may help alleviate fatigue in this population.

Key Words: Chronic heart failure; Fatigue; Anxiety; Depression; Influencing factors

Core Tip: Chronic heart failure often causes significant fatigue during long-term treatment and rehabilitation. This study found that anxiety, depression, comorbidities, advanced New York Heart Association functional class (III-IV), and poor sleep quality all contribute to increased fatigue in patients with chronic heart failure. Clinically, managing comorbidities, improving cardiac function, and providing sleep and psychological interventions may help alleviate fatigue in this population.

INTRODUCTION

Chronic heart failure (CHF) is a cardiovascular condition resulting from myocardial damage due to primary heart diseases such as cardiomyopathy and myocardial infarction, leading to impaired cardiac pumping function[1]. CHF is characterized by a prolonged disease course, difficulty in achieving a cure, and frequent relapse. Consequently, many patients experience severe fatigue during long-term treatment and rehabilitation[2]. Fatigue is a multidimensional condition that, when aggravated, can lead to physical dysfunction[3] and negatively affect self-care behaviors and quality of life in patients with CHF[4]. A study found that psychological factors such as anxiety and depression are negatively correlated with self-care in patients with heart failure[5]. This suggests that emotional distress and fatigue may jointly impair the ability of patients with CHF to manage daily activities, including self-care and adherence to treatment. However, it remains unclear whether fatigue in patients with CHF mediates or worsens anxiety and depression, or whether anxiety and depression further aggravate fatigue. Therefore, this study examined fatigue in patients with CHF and explored contributing factors - including anxiety and depression - to provide a clearer understanding and a stronger basis for improving quality of life and guiding rehabilitation management.

MATERIALS AND METHODS

Research object

This observational study included 162 patients with CHF who visited the Department of Cardiology, Suzhou Ninth Hospital Affiliated to Soochow University, between May 2023 and May 2025. Inclusion criteria: (1) Met the diagnostic criteria in the diagnosis and treatment guidelines for acute and CHF[6] and were clinically confirmed with CHF; (2) Were aged ≥ 18 years; (3) Had normal cognition with adequate reading comprehension and communication skills to independently complete questionnaires; and (4) Provided informed consent to voluntarily participate. Exclusion criteria: (1) Had malignant tumors; (2) Had a history of drug abuse; (3) Had severe mental illness (e.g., dementia, schizophrenia, or delusional disorders); or (4) Were unable to complete the questionnaire for any reason.

Research methods

Data collection: General demographic and clinical characteristics were obtained from a structured survey form, including age, sex, education level, place of residence, monthly household income, New York Heart Association (NYHA) functional class, comorbidities [e.g., anemia, chronic obstructive pulmonary disease (COPD), hypertension, and diabetes], heart failure course, and sleep status.

Fatigue assessment: Fatigue was evaluated using the Chinese version of the Multidimensional Fatigue Scale (MFI-20)[7], which comprises five dimensions - general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue - across 20 items. Each item is rated on a 5-point Likert scale (1-5 points), yielding a total score range of 20-100. Higher scores indicate greater fatigue.

Anxiety assessment: Anxiety was assessed using the Self-Rating Anxiety Scale[8]. The scale consists of 20 items, of which 15 items are positively scored and five are negatively scored. Each item is rated on a 4-point Likert scale (1-4). The raw score is the sum of all items, which is multiplied by 1.25 and rounded to the nearest integer to obtain the standard score. A standard score above 50 indicates anxiety, with higher scores reflecting more severe anxiety.

Depression assessment: Depression was evaluated using the Self-Rating Depression Scale[9]. The scale consists of 20 items, with 10 positively scored and 10 negatively scored. Each item is rated on a 4-point Likert scale (1-4), and the total raw score is the sum of all items. The standard score is obtained by multiplying the raw score by 1.25 and rounding it to the nearest integer. A score above 53 indicates depression, with higher scores reflecting greater severity.

Statistical analysis

Analyzed using SPSS 23.0. Quantitative data are expressed as mean ± SD. Independent sample t-tests were used for comparisons between two groups, and the one-way analysis of variance (F-test) was used for comparisons among multiple groups. Pearson correlation analysis was used to assess the correlations among anxiety, depression, and fatigue. Multiple linear regression was used to identify factors associated with fatigue in patients with CHF (inclusion criterion α = 0.05; exclusion criterion α = 0.10). A P value < 0.05 was considered statistically significant.

RESULTS

Participant characteristics

A total of 162 patients with CHF were included. The majority were ≥ 60 years old (113, 69.75%), and 94 (58.02%) were male. Educational levels were as follows: Junior high school or below (86, 53.09%), secondary specialized or high school (49, 30.25%), and college or above (27, 16.66%). Participants were nearly evenly split by residence, with 82 (50.62%) living in urban areas and 80 (49.38%) in rural areas. Monthly household income was ≥ 8000 RMB in 71 cases (43.83%) and < 8000 RMB in 91 cases (56.17%). Regarding clinical characteristics, 49 patients (30.25%) were classified as NYHA functional classes I-II, and 113 (69.75%) as III-IV. Comorbidities were present in 122 patients (75.31%) and absent in 40 (24.69%). Duration of heart failure was < 3 years in 52 patients (32.10%), 3-5 years in 79 (48.77%), and 5 years in 31 (19.13%). Sleep quality was rated as good in 36 patients (22.22%), general in 85 (52.47%), and poor in 41 (25.31%).

Fatigue status and univariate analysis of patients with CHF

Based on the MFI-20, the mean total fatigue score among the 162 patients with CHF was 70.76 ± 8.42 points. Mean scores for the five dimensions were as follows: Reduced activity, 15.96 ± 2.53; physical fatigue, 15.38 ± 2.45; general fatigue, 14.47 ± 2.36; decreased motivation, 12.97 ± 2.06; and mental fatigue, 11.98 ± 2.65. Univariate analysis indicated that comorbidities, NYHA functional class, and sleep quality were significantly associated with fatigue levels (P < 0.05; Table 1).

Table 1 Univariate analysis of fatigue in chronic heart failure patients, n (%).

Basic information	Number of people	MFI-20 (points)	t/F value	P value
Age			1.791	0.075
< 60 years	49 (30.25)	68.89 ± 7.27
≥ 60 years	113 (69.75)	71.57 ± 9.31
Gender			0.189	0.849
Male	94 (58.02)	70.65 ± 8.34
Female	68 (41.98)	70.91 ± 8.95
Educational level			0.104	0.901
Junior high school or below	86 (53.09)	71.04 ± 9.42
Secondary specialized or high school	49 (30.25)	70.57 ± 8.66
College or above	27 (16.66)	70.21 ± 7.82
Place of residence			1.536	0.127
Urban	82 (50.62)	69.73 ± 8.26
Rural	80 (49.38)	71.82 ± 9.05
Monthly household income (RMB)			1.640	0.103
≥ 8000	71 (43.83)	69.45 ± 8.27
< 8000	91 (56.17)	71.78 ± 9.48
Comorbidity			5.128	< 0.001
Have	122 (75.31)	72.94 ± 9.97
No have	40 (24.69)	64.11 ± 7.62
NYHA functional class			4.546	< 0.001
Level I-II	49 (30.25)	66.16 ± 5.20
Level III-IV	113 (69.75)	72.75 ± 9.54
Course of heart failure			2.406	0.094
< 3 years	52 (32.10)	68.75 ± 7.35
3-5 years	79 (48.77)	71.33 ± 8.64
> 5 years	31 (19.13)	72.68 ± 9.98
Sleep quality			15.240	< 0.001
Good	36 (22.22)	64.26 ± 5.87
General	85 (52.47)	71.72 ± 8.71
Poor	41 (25.31)	74.48 ± 9.65

MFI-20: Multidimensional Fatigue Scale score; NYHA: New York Heart Association.

Correlations between anxiety, depression, and fatigue

The mean Self-Rating Anxiety Scale anxiety score was 58.87 ± 9.92 points, and the mean Self-Rating Depression Scale depression score was 54.76 ± 7.91 points. Pearson correlation analysis showed that both anxiety and depression scores were positively correlated with MFI-20 total scores (r = 0.479 and r = 0.468, respectively; both P < 0.001; Figure 1).

Figure 1 Correlation between Self-Rating Anxiety Scale score, Self-Rating Depression Scale score, and Multidimensional Fatigue Scale score. A: Correlation between Self-Rating Anxiety Scale score and Multidimensional Fatigue Scale score; B: The correlation between Self-Rating Depression Scale score and Multidimensional Fatigue Scale score. SAS: Self-Rating Anxiety Scale; SDS: Self-Rating Depression Scale; MFI-20: Multidimensional Fatigue Scale score.

Multivariate regression analysis of fatigue in patients with CHF

The total fatigue score was used as the dependent variable, while statistically significant factors from the univariate analysis (comorbidities, NYHA functional class, and sleep quality), along with anxiety and depression scores, were included as independent variables. All variables were categorized and coded as described in Table 2. Stepwise multiple linear regression analysis indicated that comorbidities, NYHA functional class (III-IV), poor sleep quality, anxiety, and depression were significant predictors of fatigue in patients with CHF (P < 0.05; Table 3).

Table 2 Explanation of variable assignment.

Variable	Data type	Description of valuation
Complication	Categorical data	0 = no have; 1 = have
NYHA cardiac function classification	Categorical data	0 = level I-II; 1 = level III-IV
Sleep state	Categorical data	0 = good; 1 = general; 2 = poor
Anxiety score	Continuous variable data	Enter actual value
Depression score	Continuous variable data	Enter actual value

NYHA: New York Heart Association.

Table 3 Multivariate regression analysis of fatigue in chronic heart failure patients.

Factor	Β (95%CI)	SE	Beta	t value	P value
Complication	0.903 (0.258-1.695)	0.243	0.427	4.578	< 0.001
NYHA cardiac function grade III-IV	0.319 (0.269-0.743)	0.117	0.401	4.054	0.002
Sleep state
General	0.143 (-0.169-0.459)	0.139	0.574	1.862	0.096
Poor	0.465 (0.294-0.948)	0.147	0.665	5.691	< 0.001
Anxiety	1.728 (0.693-3.642)	0.382	0.239	5.843	< 0.001
Depressed	1.649 (0.712-3.517)	0.353	0.216	5.478	< 0.001

Note: In multiple regression analysis, variables with assignment = 0 are used as controls (dummy argument). CI: Confidence interval; NYHA: New York Heart Association.

DISCUSSION

Fatigue is a common and debilitating symptom of CHF[10]. In this study, the mean MFI-20 fatigue score among patients with CHF was 70.76 ± 8.42, representing a moderate-to-high level compared with the scale midpoint of 50. The score is significantly higher than that reported in a previous international study (36.20 ± 9.30)[11] but similar to the findings of Chinese scholars Yang et al[12] (62.45 ± 13.55). This suggests that fatigue levels among patients with CHF in China are generally at a moderate-to-high level. Skotzko et al[13] reported that personality traits and mental disorders - including mood disorders, anxiety, and schizophrenia - can influence the perception of physical fatigue in CHF. These findings highlight the impact of anxiety and depression on both physical and psychological fatigue in patients with CHF. Early screening and identification of patients with CHF experiencing severe fatigue are essential for guiding clinical interventions aimed at alleviating this symptom.

Anxiety and depression are common psychological responses in patients with CHF[14]. This may be attributed to the prolonged disease course, which imposes increasing physiological constraints, such as dyspnea and reduced exercise tolerance. Long-term illness and the risk of unpredictable acute deterioration can make patients anxious, irritable, and distressed, leading to symptoms of anxiety and depression[15,16]. Previous research has shown that persistent worry and rumination consume substantial mental energy, deplete physiological reserves, and contribute to cognitive and physical fatigue[17]. In addition, depressive symptoms play a parallel and positive mediating role in the relationship between anxiety and fatigue[18]. These findings suggest a close connection among anxiety, depression, and fatigue. Consistent with prior studies, our investigation found that more severe symptoms of anxiety and depression were positively correlated with higher levels of fatigue in patients with CHF. One possible explanation is that CHF causes breathing difficulties and general weakness, which limit daily activity tolerance and may even hinder self-care. These functional limitations often lead to persistent negative emotions, including despair and a sense of defeat[19]. Psychological stress, such as anxiety and depression, can also lead to neuroendocrine disorders, including overactivation of the hypothalamic-pituitary-adrenal axis, excitation of the sympathetic nervous system, and hyperactivity of the renin-angiotensin system. These changes elevate cortisol and catecholamine concentrations, increase renin secretion, and promote water and sodium retention, thereby worsening CHF[20]. As CHF progresses, reduced cardiac output limits blood and oxygen supply, leading to impaired brain function, decreased cognitive ability, and heightened mental fatigue[21]. Additionally, worsening CHF reduces activity, decreases motivation, and causes physical exhaustion[22], all of which further exacerbate fatigue.

Clinically, many patients with CHF have comorbidities such as anemia or COPD. These conditions exacerbate negative emotions, including anxiety and depression[23,24], and their pathological effects further increase physical fatigue[25]. The present analysis found that comorbidities are significant contributors to fatigue in patients with CHF. Patients with anemia or COPD often experience palpitations and shortness of breath, which increase both psychological distress and physical fatigue. Furthermore, the presence of comorbid diseases raises the body’s metabolic demand, further intensifying fatigue. A higher NYHA functional class indicates poorer cardiac pumping ability. Fomicheva et al[26] reported that patients in NYHA classes III-IV exhibit greater physical fatigue, which is consistent with our findings. Reduced cardiac output in these patients fails to meet the basic oxygen and energy demands of body tissues, especially muscle, thereby increasing physical fatigue[27]. Sleep is an important regulatory mechanism for the human body, and adequate sleep promotes recovery. However, insomnia is common among patients with CHF[28]. Our study found that poor sleep quality contributes to fatigue in this population, likely because it leads to insufficient energy and mental exhaustion[29]. Poor sleep quality can also negatively impact a patient’s mental health, increasing the risk of anxiety and depression[30]. Further analysis confirmed that anxiety and depression are significant contributors to fatigue in patients with CHF, possibly because the chronic and progressive nature of the disease intensifies both physical and emotional burdens. This interaction creates a negative feedback loop that impairs patients’ self-care capacity and psychological resilience, aggravates physical fatigue, and perpetuates a vicious cycle. To address these influencing factors, medical staff should consider the following measures: (1) Patients should be encouraged to manage comorbidities by regularly monitoring comorbid conditions, adhering to prescribed medications, and maintaining adequate rest to avoid excessive fatigue; (2) Cardiac function should be improved by appropriately increasing patients’ activity levels through resistance training and aerobic exercises, such as walking, jogging, and practicing Tai Chi; (3) Poor sleep quality should be improved by applying foot bath therapy three times a week for about 25 minutes at 40 °C. Warm stimulation of the peripheral nerves in the feet may relax the cerebral cortex, promoting comfort, facilitating sleep onset, and improving sleep depth; and (4) More attention should be paid to mental illnesses and psychological health by taking measures to improve patients’ psychological states. For example, cognitive intervention can be conducted during psychological counseling once a week for 10-20 minutes. These sessions should focus on explaining the clinical features, treatment measures, and prognosis of the disease, which would help patients overcome misconceptions and adopt a more positive attitude toward their illness. Concurrently, behavioral intervention can be implemented twice daily for 20-30 minutes. These sessions should guide patients through sequential contraction and relaxation - from the upper limbs, face, and trunk to the lower limbs - promoting psychological relaxation through physical relaxation and alleviating symptoms of anxiety and depression.

Our study has several limitations: First, as a cross-sectional survey, causal relationships among variables cannot be inferred. Future research should use prospective cohort studies to further confirm these findings. Second, this study included only inpatients with CHF from a single hospital, resulting in a relatively high proportion of patients in NYHA class III-IV. This may limit the generalizability of the results. Future research should include outpatients and a broader patient population to better explore fatigue and psychological conditions across different sources. Third, although this study confirmed the relationship between fatigue and anxiety and depression, the cross-sectional design captures data at a single time point and cannot explain the fluctuation in fatigue or psychological symptoms over the course of the disease. Future research should include follow-up assessments to analyze the trajectories of fatigue and psychological symptoms, enabling the development of tailored clinical interventions. Fourth, since this study was designed as a cross-sectional survey and did not conduct substantial measurements of relevant blood indicators, our analysis of fatigue and psychological mechanisms of patients with CHF relied primarily on literature-based speculations. Future research should incorporate objective physiological measurements to verify the “psycho-physiological” pathways.

CONCLUSION

Patients with CHF experience high levels of fatigue. Anxiety and depression are positively correlated with fatigue, and factors such as comorbidities, NYHA functional class (III-IV), poor sleep quality, and psychological distress all contribute to fatigue in this population. Clinically, it is essential to manage comorbidities, improve cardiac function, and provide sleep and psychological interventions to alleviate the fatigue experienced by these patients.