Introduction

Heart failure (HF), the end stage of many heart diseases, is a complex clinical condition caused by the decline in cardiac pumping function (Onohara et al., 2022). Common symptoms of HF include fatigue, shortness of breath, dyspnea, peripheral edema, and exercise capacity limitations, all of which interfere with physical, spiritual, and social well-being and result in poor health-related quality of life (HRQoL; MacMahon & Lip, 2002). Negative experiences of symptoms and insufficient coping strategies may accompany the illness, further decreasing the acceptance of necessary lifestyle modifications and worsening the disease prognosis (Johansson et al., 2021; Park et al., 2022). Resilience level has been identified as an important factor influencing how patients perceive their HRQoL (Yazdi-Ravandi et al., 2013; Zhang et al., 2017). With life expectancy continuing to increase in patients with HF, it is important to explore and clarify the relationship in this patient group between resilience and HRQoL.

HF is a growing medical problem worldwide that is more prominent among older adults and shows better survival rates in patients with hypertension, arrhythmia, coronary artery disease, and myocardial infarction. The prevalence of HF is expected to continue to rise (Cho & Yoo, 2021). The influence of HF is limited to not only the physical dimension but also the psychological, social, and spiritual dimensions (MacMahon & Lip, 2002). The severity of HF and its symptoms results in differing levels of daily life limitations among patients with HF. Experiencing negative emotions such as depression or anxiety has been documented to influence patient compliance and further hinder lifestyle changes. The results of many studies highlight the importance of patient compliance and lifestyle modification to successful HF care (Park et al., 2022). Furthermore, physical and psychosocial factors are associated with HRQoL and should not be neglected in patients with HF (MacMahon & Lip, 2002; Moryś et al., 2016).

HRQoL is perceived and determined subjectively and may be influenced by multidimensional factors. HRQoL can be classified into physical, mental, and social aspects. Stress related to bodily symptoms, sadness, worry about life, and uncertainty are believed to lead to poorer quality of life among people suffering from diseases (Kang & Choi, 2019). Thus, individual feelings, stress status, coping strategies, socioeconomic status, and cultural and social functioning have been mentioned in the literature as essential factors to consider when evaluating HRQoL in patients (Ferrans & Powers, 1985; S. Heo et al., 2022). HRQoL in patients with HF is an important construct for assessing health and treatment outcomes. HF symptoms, New York Heart Association functional class (NYHA-FC), and depression are known to affect HRQoL (Blinderman et al., 2008; Franzén et al., 2006), and HRQoL has been associated with readmission and hospital stay frequencies (Garin et al., 2014). Moreover, poor HRQoL is a strong and independent predictor of all-cause death and morbidity in patients with HF (Johansson et al., 2021). Coping style is a predictor of HRQoL, which reflects resilience.

Resilience has been defined by the American Psychological Association in 2004 as the process of adapting well while facing adversity, trauma, tragedy, threats, or significant stress (as cited in Newman, 2005). Resilience and coping are related but different, with resilience reflecting the adaptive capacity to recover from stress and coping reflecting the cognitive or behavioral strategy used to manage stressful events (Wu et al., 2020). The role of resilience in patients with heart disease has been a focus of research interest for several years. Resilience plays an important role in adapting to disease and is associated with disease prognosis (Park et al., 2022). Numerous studies consider resilience to be a defense mechanism used to deal with disease treatment and self-management (Bosworth et al., 2004; J. M. Heo & Kim, 2020; Liu et al., 2015). The results of a recent systematic review indicate that resilience is relevant to responding to stressful conditions such as acute coronary syndrome or other cardiovascular diagnoses that require patients to change behaviors. Thus, enhancing resilience may be a way to improve these patients' HRQoL (Love et al., 2021).

Because most studies in the literature treat resilience as a moderator/mediator between psychological variables and HRQoL, there is little information available about the direct relationship between resilience and HRQoL, particularly in patients with HF. Therefore, the purpose of this research was to fill this knowledge gap by comprehensively understanding the relationship between resilience and HRQoL in patients with HF.

Methods

A cross-sectional design was employed, and patients with HF were recruited from June 2016 to February 2017 in the heart center of a general hospital in northern Taiwan.

Sample

The inclusion criteria for participants included (a) diagnosed with NYHA-FC II or III, (b) visited the outpatient department of cardiology, (c) aged at least 20 years, and (d) able to read and understand spoken Mandarin. Patients with a psychiatric diagnosis or who were unconscious and unable to communicate were excluded.

Sample Size

G*Power Version 3.1 was used to determine the minimum sample size for this single-sample study based on an F test with linear multiple regression, a medium effect size of 0.4, an alpha of .05, a power of 95, and 13 predictors. The effect size was estimated based on the recommendations of Hanyu et al., who examined quality of life in patients with HF (Ni et al., 2000). A sample of at least 79 individuals was determined for this study, and 100 participants were enrolled and considered in the data analysis.

Data Collection

Patients who met the sample criteria were recruited in person by the researcher during their return visit to outpatient departments. Participants were well informed about the study and completed the informed consent form. Data were collected using three questionnaires: demographic/medical, resilience, and quality of life.

Measurements

This study used structured questionnaires for data collection. Demographic data included the participant's date of birth, gender, marital status, educational level, employment status, personal income, and primary care provider. Medical data included time since HF diagnosis, first and current left ventricular ejection fraction, and NYHA-FC. The NYHA-FC distinguishes patients into one of four categories based on symptoms, as follows: FC I = no limitation of physical activity (ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea); FC II = slight limitation of physical activity, comfortable at rest (ordinary physical activity results in fatigue, palpitation, or dyspnea); FC III = marked limitation of physical activity, comfortable at rest (less-than-ordinary activity causes fatigue, palpitation, or dyspnea); and FC IV = unable to carry on any physical activity without discomfort (symptoms of HF at rest, and discomfort increases when any physical activity is undertaken; Russell et al., 2009).

The Resilience Scale for Adults (RSA) was used to assess resilience level. The RSA was developed by Friborg and his colleagues and is a 33-item scale measuring the following five protective dimensions: personal strength, family cohesion, social resources, social competence, and structured style (Friborg et al., 2003, 2005). RSA is scored using a 7-point Likert scale ranging from 33 to 231. The Cronbach's alpha ranges from .67 to.81 for each dimension, and the overall Cronbach's alpha was calculated as .88 (Hjemdal et al., 2006). The RSA-Mandarin Version (RSA-MV) was translated by Wang and modified into a 29-item scale in six protective dimensions using the maximum likelihood method. The Cronbach's alpha of the RSA-MV was .89 for the total scale and .92, .85, .85, .83, and .87 for each factor, respectively (Wang, 2007).

In this study, the 12-item Short Form Health Survey (SF-12) was used to evaluate quality of life. The SF-12 is a self-administered questionnaire, with each item scored between 0 (lowest level of function) and 100 (highest level of function). The SF-12 comprises two components, namely, a physical component summary and a mental component summary, and provides scale scores for general health (GH), physical function (PF), role physical, bodily pain (BP), mental health, role emotional, vitality, and social function (Fong et al., 2021).

Statistical Analysis

The collected data were analyzed using SPSS Statistics Version 22.0 (IBM Inc., Armonk, NY, USA). Data were summarized using percentages, means, and standard deviations. The Mann–Whitney U test was used to assess between-group differences. A canonical correlation analysis (CCA) was used to examine the relationship between RSA-MV and SF-12 among patients with HF at NYHA-FC II and III. The CCA was conducted using five dimensions of the RSA-MV and eight scale scores of the SF-12.

Ethical Considerations

The institutional review board at the participating hospital approved the study ([513]104A-49). The participants signed informed consent after receiving an explanation of the potential benefits and harms of engaging in the study and learning that they could withdraw from the study at any point without any negative consequences. All personal information, questionnaire responses, and related data were used only for research purposes.

Results Demographics and Medical Characteristics

The demographics and medical characteristics of the 100 participants are shown in Table 1. The mean age was 65.52 years, and 44% were female. Sixty-two percent were married. The largest percentage (34.0%) had an educational level between junior high and high school, followed by elementary school (32.0%). Slightly over one quarter (28.0%) were employed, and 46.2% had income by themselves. Furthermore, 61.3% could take care of themselves, and 24.2% were cared for by their children. The average duration since HF diagnosis was 5.91 years, and the mean left ventricular ejection fraction was 45.43%. Most of the participants were categorized as NYHA-FC II (56%), with 44% categorized as NYHA-FC III.

Table 1. - Demographic Characteristics of the Participants (N = 100) Variable n % Gender (female) 44 44.0 Age (years; M and SD) 65.52 14.47 Marital status  Married 62 62.0  Unmarried 11 11.0  Widowed 17 17.0  Divorced 10 10.0 Educational level  Illiterate 11 11.0  Elementary 32 32.0  Junior high to high 34 34.0  Associate degree 23 23.0 Employee status (yes) 28 28.0 Personal income a  Self 49 46.2  Pension 39 36.8  Relatives or friends 17 16.0 Primary care provider a  Self 76 61.3  Parents 3 2.4  Child 30 24.2  Nursing home 10 8.1  Friend 3 2.4 Time since heart failure (years; M and SD) 5.91 5.22 Left ventricular ejection fraction (%; M and SD) 45.43 18.66 NYHA-FC  I 56 56.0  II 44 44.0

Note. NYHA-FC = New York Heart Association functional class.

a Multiple choice.

Dimensions of and Correlation Between Resilience and Health-Related Quality of Life

The mean scores for each dimension of resilience and HRQoL are shown in Table 2. Resilience was assigned x variables (x1 = personal strength, x2 = family cohesion, x3 = social resources, x4 = social competence, x5 = structured style), and the SF-12 was assigned y variables (y1 = GH, y2 = PF, y3 = role physical, y4 = BP, y5 = mental health, y6 = social function, y7 = role emotional, y8 = vitality). The correlations between the five x variables and eight y variables in NYHA-FC II and III are presented in Table 3.

Table 2. - Detailed Dimensions of Resilience and Health-Related Quality of Life in Patients With Heart Failure Variable Total (N = 100) NYHA-FC II (n = 56) NYHA-FC III (n = 44) Mann–Whitney U p M SD M SD M SD Resilience 113.54 7.70 113.71 8.02 113.32 7.35 1201.0 .829  Personal strength 24.24 3.01 24.16 2.76 24.34 3.33 1198.5 .815  Family cohesion 26.02 4.50 25.77 4.22 26.34 4.87 1050.0 .204  Social resources 31.69 3.59 31.82 3.69 31.52 3.49 1159.5 .613  Social competence 15.61 2.43 15.96 2.35 15.16 2.49 962.0 .056  Structured style 15.98 2.89 16.00 2.87 15.95 2.96 1217.0 .916 Health-related quality of life  Physical component scale 52.50 26.81 61.83 24.68 40.63 24.87 671.5 < .001***  General health 28.75 25.96 33.04 22.92 23.30 28.73 907.5 .018*  Physical function 45.50 37.16 54.46 36.65 34.09 34.98 852.5 .007**  Role physical 61.38 37.78 75.00 33.79 44.03 35.71 663.0 < .001***  Bodily pain 72.50 33.62 79.02 30.44 64.20 35.93 931.5 .024*  Mental component scale 62.63 24.90 68.38 24.86 55.30 23.21 834.0 .006**  Mental health 68.88 35.91 75.22 36.81 60.80 33.41 882.0 .010*  Social function 78.75 31.66 82.59 29.36 73.86 34.08 967.5 .063  Role emotional 59.88 26.43 64.51 25.31 53.98 26.93 789.0 .002**  Vitality 39.50 30.60 48.21 30.47 28.41 27.28 1043.5 .129

Note. NYHA-FC = New York Heart Association functional class.

*p < .05. **p < .01. ***p < .001.

Table 3. - Correlation Between the Dimensions of Resilience and Health-Related Quality of Life in Heart Failure Patients Variable General Health Physical Function Role Physical Bodily Pain Mental Health Social Function Role Emotional Vitality NYHA-FC II  Personal strength .259 −.079 .071 −.154 −.029 .135 −.256 −.027  Family cohesion .034 −.017 −.215 −.120 −.259 −.132 −.159 −.074  Social resource −.063 .218 .124 −.119 −.042 −.120 .013 −.042  Social competence .005 .102 .097 .256 .200 .120 .367** .136  Structured style .035 −.082 .305* −.104 .045 .147 .036 .038 NYHA-FC III  Personal strength .001 .048 −.044 .046 .034 −.009 −.052 −.104  Family cohesion .013 −.309* −.097 −.341* .156 .114 .280 −.103  Social resource .108 −.040 .128 .129 .048 −.050 .164 .049  Social competence −.110 .090 −.159 .241 −.140 −.062 .223 .050  Structured style −.459** −.328* −.424** −.333* −.333* −.330* −.337* −.295

Note. NYHA-FC = New York Heart Association functional class.

*p < .05. **p < .01. ***p < .001.

Canonical Correlation Analysis and the Variance in Canonical Function

CCA was applied to examine the relationship between each dimension of resilience and HRQoL. Standardized canonical coefficients were calculated, and the first canonical function reached statistical significance for both NYHA-FC II and III. The first canonical correlation was .502 for NYHA-FC II (Λ = 0.264, F = 1.701, p = .010) and .519 for NYHA-FC III (Λ = 0.185, F = 1.628, p = .021). For the NYHA-FC II group, the dimensions of personal strength (rs = .76) and social competence (rs = −.58) contributed the most to resilience, whereas social function (rs = −.86) and emotional role (rs = −1.00) contributed the most to quality of life. For the NYHA-FC III group, the dimensions of family cohesion (rs = −.92) and social competence (rs = .19) contributed the most to resilience, whereas PF (rs = .47) and BP (rs = .47) contributed the most to quality of life. The details on these coefficients are shown in Figure 1.

Figure 1.:

Conceptual Model for the Canonical Correlation Between Resilience and Health-Related Quality of Life Dimensions: (A) NYHA-FC II Group and (B) NYHA-FC III GroupNote. NYHA-FC = New York Heart Association functional class.

Discussion

The focus of most previous related studies has been on evaluating the relationships between resilience and quality of life in various populations (Edward et al., 2019; Koivunen et al., 2022; Tedrus et al., 2020). To our knowledge, this is the first study to examine the relationships between each dimension of resilience and HRQoL in patients with HF and to compare the differences among patients in different functional status categories.

The many studies on the physical condition, resilience, and psychological aspects of patients with HF have mainly addressed the sample as a whole instead of considering different groups in terms of left ventricular ejection fraction and functional abilities. This study was the first to examine different HF levels and analyze the data separately. The main difference between NYHA-FC II and III is the degree of influence that the physical symptoms of HF have on a patient's tolerance for performing normal daily activities. Russell et al. (2009) used objective measurements such as peak oxygen consumption (peak VO2), end-tidal carbon dioxide, and exercise time to compare patients in different NYHA functional classes. Their finding supports that the physical component is associated significantly with subjective HF classification. Since then, many studies have used the 6-minute walk distance (6MWD) as a tool and found a significant difference in 6MWD between NYHA-FC II and III (Yap et al., 2015). The result in this study is in line with another study on patients with hip fracture that found better psychological resilience can help patients achieve functional independence (Tan et al., 2021). It was also shown that patients in the NYHA-FC II class had better resilience than those in NYHA-FC I, possibly because patients developed resilience in response to disease severity (Bang et al., 2013). Previous studies have identified significant differences in physical functioning between NYHA-FC II and III and in resilience between NYHA-FC I and II. The value of this study was the examination of the direct relationship between resilience and functional classification in patients with HF and the finding that neither psychological resilience nor its five dimensions were significantly related to the functional category status. Thus, whereas HF symptoms lead to divergent functional activity levels, level of patient resilience does not seem to be driven by physical function or symptoms.

HF is a disease that changes the functioning of the circulatory system, lungs, and muscles and, as a chronic disease, also affects the psychological dimension (S. Heo et al., 2022; Ye et al., 2021). 6MWD and daily physical performance are known to relate to quality of life, and having better physical activity capacity can reduce psychological disturbances such as fatigue and depression symptoms and result in better HRQoL (Blumenthal et al., 2012; Norman et al., 2020). The unpredictable and uncertain progress of HF often results in patient frustration toward their disease. Anxiety, fear, depression, burnout, and concern about becoming a burden are common in individuals with HF. Losing the ability to perform normal work and to maintain social roles has been found to influence quality of life negatively in patients with HF. In addition, denial of symptoms and hesitation to seek medical help by patients with HF have been associated with patient fear of becoming a burden on their families (Bosworth et al., 2004). Thus, the findings showed that, although the experiences of emotional on individual roles differed significantly among NYHA groups, there was no statistically significant difference in “social function” in the mental component summary.

HF is an intense, unpredictable, and stressful chronic disease, and a patient's adaptive capacity to recover from it is crucial to successful disease management and prognosis. This study found personal strength to be the dominant component of resilience for patients in the NYHA-FC II class. Personal strength measures the level of self-esteem, self-efficacy, hope, and subjective realistic orientation to life of an individual (Friborg et al., 2003). When confronting life events such as health problems, a patient's personality plays a critical role in successful management and adaptive coping. Positive personalities such as extraversion, hopefulness, and openness have been associated with resilience and disease progression (Jalilianhasanpour et al., 2018). The same phenomenon may apply to patients with HF both in acute care settings and in clinical follow-up. Patients with HF who express optimism about surviving life-threatening diseases and feel positive about a renewed life tend to handle their disease better than those who are more pessimistic. HF symptoms in the NYHA-FC II class are mildly felt when patients perform daily activities, implying that most patients in this group handle daily life activities on their own. For patients in this class, resilience to HF draws on personal strength and personality. Meanwhile, GH condition was found to have the most significant effect on HRQoL in this group. Although Functional Class II patients experience mild symptoms during daily performances, they also worry whether they have comorbidities and/or are aware of health-associated feelings. Every sensation from the body influences a patient's commitment to quality of life.

Family cohesion, the dominant component of resilience in the NYHA-FC III group, encompasses loyalty, family conflict, cooperation, support, mutual understanding, and appreciation among family members (Friborg et al., 2003; Wang, 2007). Patients with HF whose symptoms present constantly and who only feel relieved while resting are categorized as Functional Class III. Under these circumstances, handling daily life and activities is problematic, and they need to shift their responsibility to family members and rely on their help. In Chinese culture, family members are expected to work as a unit when facing serious life events, and caring for each other is a natural responsibility. Thus, level of family cohesion influences the response of family members with health problems in terms of suicidal ideation, depression, coping styles, resilience, and disease progression (Zhou et al., 2020). A previous study found that family cohesion can promote recommended health behaviors and life satisfaction, increase the self-perceived need for healthcare, and strengthen personal resilience (Opsomer et al., 2022). A well-developed family provides comprehensive, multidimensional support to its members. Thus, higher levels of family cohesion may be expected to be associated with greater attention given to the adaptability and management of patients with HF to their disease. Because HF is a chronic health issue requiring long-term management and medical follow-up, lifestyle modification and compliance retention are important to managing this disease. With family support, patients with HF receive help from family members, reinforcing patients in the physical, mental, or social dimensions and allowing them to focus on coping with their symptoms. The findings of this study indicate that, in patients in Functional Class III, PF and BP are the major components affecting HRQoL. Patients with HF in this class spent significant effort coexisting with HF symptoms and/or its comorbidities. Although experiencing symptoms while performing daily activities is not surprising, some patients regard a day with more tolerance to physical activities and fewer symptoms or aches as a mercy (Freedland et al., 2021). Thus, being symptomless and painless may be interpreted subjectively as a better quality of life.

This study was affected by several limitations. First, patients with HF were selected from a general hospital using purposive sampling. Thus, the results may not represent the condition throughout Taiwan. Further studies should recruit a larger sample of patients with HF at multiple centers. Second, functional class was evaluated on the day of data collection. Thus, possible changes in class status that may impact their resilience and quality of life could not be considered. Further study is needed to understand the trend in patient experience using qualitative interviews to support quantitative findings. Finally, because of the relatively small sample size for canonical correlation, the findings may have been affected by bias.

Conclusions

HF is an unpredictable, intense, and stressful chronic disease that requires patients to invest significant time and effort on confronting symptoms and comorbidities and trying to accept the dramatic changes in their health condition and individual role. Although many studies have studied various factors affecting population