Atrial fibrillation (AF) is an unpleasant and life disabling heart rhythm disorder when symptomatic, and is afflicting a high and growing number of people all over the world. In Denmark, 20.000 new people are diagnosed with the disorder each year and 130.000 people are living with AF. The numbers are expected to raise further due to an ageing population, improved overall survival from cardiac diseases and increase in risk factors causing AF including physical inactivity, obesity, alcohol over-consumption, smoking, diabetes, high blood pressure and obstructive sleep apnoea. AF causes mental distress, reduced health-related quality of life (QoL) and a high number of hospital readmissions; 10-40% annual readmission rate internationally. In Denmark readmission rates is around 7.5% [regional interval 5.6-9.5%]. Thus, hospital readmissions lay enormous organisational and economic strain on the health care system. The societal cost is around 1-2% of the total healthcare costs in Denmark, with hospital admissions as the primary cost driver.
Promising results from systematic reviews and randomised controlled trials (RCT) show that rehabilitation including patient education and physical activity have the potential to reduce symptom-burden, mental distress, improve QoL and reduce hospital readmissions in people with AF. Also, international and Danish guidelines recommend rehabilitation in AF. In 2018, the Danish municipalities got the formal and legal responsibility to include people with AF in the already existing generic cardiac rehabilitation (CR) program aimed at people with ischemic heart disease (IHD) and cardiac heart failure (CHF). However, the transfer of CR interventions from one cardiac condition to another, and from hospital to municipality setting, was not followed by any direct instructions or further qualifications of the intervention to handle this new patient-group in a new setting. Thus, leaving the municipalities as new health care provider with a number of unanswered questions of which some are addressed in this PhD proposal.
What are the core components of municipality-based cardiac rehabilitation for people with AF?
CR for people with IHD include the following core components: physical exercise, patient education, psychosocial healthcare, dietary intervention, smoking cessation and other risk factor management. This do not necessarily apply to AF. Research in rehabilitation including people with AF has mostly been focusing on physical activity and patient education.
In recent years focus on patient-centred, integrated, holistic care across sectors and health care providers has emerged within AF internationally. Integrated care is described in the European guidelines for management of AF and entails a need for a much broader view on rehabilitation and interventions in AF that would be helpful and supportive for the individual patient.
In Denmark, the municipalities by law are obliged to offer rehabilitation for hospitalized patients referred by doctor (Danish Health Law §140). Rehabilitation interventions are person-centered, aiming at the highest level of participation and inclusion of the individual. Hence, the municipalities in Denmark have great potential in contributing to an integrated, holistic care approach in AF. The core components of the municipal role in integrated care is represented by the non-pharmacological interventions as physical activity, patient education, psychosocial management and lifestyle interventions. It is unknown whether the current set-up of CR and prevention in Danish municipalities meets the needs and preferences of people with AF, and whether the expected outcomes in terms of improvement in symptom burden, psychological distress and QoL can be achieved from participation in municipality-based CR?
Further it is unknown whether psychological distress and reduced QoL in AF increases the risk of hospital readmissions as found in IHD and CHF populations.
Does anxiety and depression in people with AF increase the risk of hospital readmissions?
Psychosocial problems are frequent among people with AF and depression has been found to increase the risk of incident AF. In cardiac patients, readmissions has been predicted by anxiety and depression, perceived health, quality of life and symptom distress and these were also independent predictors of one-year mortality. As presented earlier, many people with AF experience hospital readmissions which are very expensive to the society. Whether anxiety and depression in people with AF is associated with hospital readmissions is not known. Following catheter ablation, people with AF experienced decreased mental and physical health and high readmission rates in 6 to 12 months. Hence, it is possible associations will be present in AF in general. Such knowledge would be highly valuable and call for attention especially in psychosocial management and rehabilitation for people with AF. Unique Danish data are available, to look into the association between anxiety, depression, QoL, hospital readmissions and mortality in an incident AF population.
How many people with AF will be eligible for cardiac rehabilitation in Danish municipalities?
As part of the organisational and economic planning of CR aimed at people with AF it is important to know how many would be eligible for municipality-based CR. In people with IHD, the Danish database for CR implies that at least 40% of the total IHD population would be eligible for participating in CR. However, we do not know neither in Denmark or internationally how many people with AF would be eligible for CR. A health technology assessment has shown that out of a target population of IHD patients, a proportion of the population is eligible to CR, and of these a proportion will be invited/referred to CR. Some of these will start CR (the uptaken population) and again some of these will be adherent to the CR. Multiple targets can be used to assess eligibility for CR in AF, and those are backed up by research and recommendations in handling risk factors in AF. Furthermore, the extend of overlap between AF and IHD, CHF and/or valvular disease is unknown and can all be underlying causes of AF and be targets for rehabilitation referral.
This proposed PhD aims to address the following objectives in three sub-studies:
1) To evaluate people with AF' experiences, needs and preferences in CR, and to evaluate expected change in outcomes from participating in municipality-based rehabilitation using existing data from a municipality-based feasibility study.
2) To examine the association between anxiety, depression, QoL, hospital readmissions and mortality in people with AF using existing data from a survey cohort study with register-based 5 years' follow-up.
3) To define criterions/models for assessment of eligibility to municipality-based CR and to assess the proportion of people with incident AF, who are eligible for municipality-based rehabilitation based on risk factors, their cardiac comorbidities (overlap with IHD, CHF and/or valvular disease) and their specific care needs in a large scale national survey and registry based cross-sectional study.