A prospective longitudinal study to examine the evolvement, and prognostic impact of symptom clusters in heart failure patients experiencing recent cardiac exacerbation

Abstract

Heart failure (HF) is characterised by a high level of symptom burden and repeated hospital service utilizations. Symptom cluster has evolved as a concept to provide integrated information about the underlying pathophysiological changes and psychosocial impacts of concurrent symptoms. Its manifestation in the transitional period post-HF exacerbation is especially important to inform more proactive health monitoring and care support. However, there is a dearth of studies examining the dynamic change in symptom clusters evolving in the post-discharge period. Moreover, knowledge is lacking on how symptom clusters evolve from pathophysiological background, behavioural adaptation, and psychosocial resource. This thesis attempts to address such research gaps. More importantly, the role of symptom clusters in shaping the trajectory of health-related quality of life (HRQoL) and frailty, rehospitalization and all-cause death need to be identified. The objectives of this study were: 1) To examine the evolvement of symptom clusters among HF patients from a recent decompensation to the 6-month postdischarge; 2) To evaluate the impact of symptom clusters in predicting the trajectory of HRQoL and frailty, hospital readmission, and mortality among HF patients based on an integrative theoretical framework covering the influence of pathophysiological, psycho-cognitive-behavioural, and situational perspectives on symptom clusters. This was a multi-centre longitudinal study. A total of 413 HF patients were recruited in eight hospitals in Tianjin and Shenzhen Cities in mainland China. Data covering symptom experience, frailty, HRQoL, clinical profiles, psycho-cognitive functions and situational recourses were collected. Repeated data on symptom experience, frailty, and HRQoL were collected at 1-, 3-, and 6-month post-discharge. Information about hospital readmission and mortality were retrieved from the digital health record. The key findings indicated the dynamicity of symptom clusters among HF patients who experienced cardiac decompensation. The initial symptoms presentation was categorised into dyspnoeic, congestive, gastrointestinal, ischaemic, and psychological clusters. After discharge, patients experienced a gradual resolution in symptoms indicative of severe ischaemia in vital organs and fluid accumulation in interstitial compartments and gastrointestinal tract. However, symptoms reflecting pulmonary congestion, peripheral oedema, psycho-cognitive distress, and general discomfort persisted during the 6 months post-discharge. The integrative models consistently demonstrated the significant roles of symptom clusters during cardiac decompensation in predicting unfavourable progression in HRQoL, frailty, high risk of rehospitalisation, and mortality 6 months post-discharge. Symptom clusters reflecting dyspnoeic and congestive manifestations were found to be the most detrimental. Moreover, symptom clusters significantly mediated the effects of pathophysiological and psycho-cognitive-behavioural factors on all prognostic outcomes. The protective effects of psycho-cognitive-behavioural factors were evident for HRQoL progression, rehospitalisation, and all-cause mortality, whereas pathophysiological factors played more important roles in determining frailty progression. Situational factors had more indirect effects on health outcomes by favouring the psycho-cognitive-behavioural functions in reducing burden of symptom clusters. In conclusion, this thesis developed integrative theoretical models to explain the impact of symptom clusters on the progression of HRQoL, frailty, hospital readmission and all-cause death in the post-discharge period. This is the first study to identify the dynamicity of symptom clusters among HF patients in the transitional period, which informs post-discharge care.