The purpose of this study was to describe and compare the six-month trajectory of HRQOL outcomes of patients with symptomatic AF who participate in cardiac rehabilitation or receive usual care.
Methods: A prospective, observational, longitudinal design was used for this IRB approved, one-year pilot study. Subjects were recruited from a convenience sample of patients with symptomatic paroxysmal or persistent AF who were referred by their physicians to the community-based cardiac rehabilitation program of a large, tertiary care hospital in the northeastern U.S. For study inclusion, patients were required to have rate-controlled cardiac rhythm, at least one cardiometabolic risk factor, and be medically cleared for moderate exercise. A potential pool of 10 patients per month was estimated from the number of patients with AF treated in the institution’s cardiology-electrophysiology clinics. Cardiac rehabilitation staff contacted the referred patients by phone and described the program. After patients accepted or declined cardiac rehabilitation, staff invited them to participate in the research study. The intervention group received an intake interview to develop an individualized exercise and cardiometabolic risk modification care plan. They participated in 2-3 supervised, non-EKG monitored exercise sessions weekly for 12 weeks and attended educational classes for risk factor modification. Subjects who chose not to participate in cardiac rehabilitation but agreed to participate in the study were followed by their usual care providers and received risk factor modification advice and education at routine office visits.
HRQOL outcomes included AF symptoms and disease-specific quality of life. Questionnaires were collected at three time points: entry into the study/cardiac rehabilitation (T1), 3-months or completion of cardiac rehabilitation (T2), and 6-months after study entry (T3). Symptoms related to AF were assessed with the University of Toronto Atrial Fibrillation Severity Scale (AFSS) (Dorian et al., 2013). HRQOL life was assessed with the Atrial Fibrillation Effect on Quality of Life (AFEQT) instrument (Spertus et al., 2011). Permission to use the AFSS and AFEQT was obtained from the authors. Subjects received a small stipend ($25 U.S.) upon completion of the questionnaires at each time point. The modest cost of the cardiac rehabilitation program ($60 U.S. per month) was paid by an internal grant for intervention subjects.
Results: Data were analyzed with descriptive and non-parametric statistics using SPSS, version 17. Thirty-four eligible patients were referred to cardiac rehabilitation between October 2015 and March 2016. Eighty-eight percent (30/34) agreed to study participation, with 23 (77%) selecting the intervention and 7 (23%) choosing usual care. Intervention subjects were significantly younger (66 vs. 73 years, p=.017) and were more likely to present with paroxysmal versus sustained AF (p=.044) compared to the usual care group. The majority of subjects reported a history of hypertension, hyperlipidemia, central obesity, orthopedic limitations, and no regular exercise at baseline. Intervention subjects were significantly more likely to have been treated with cardioversion (15/23, 65%) than the usual care group (1/6, 17%) (p=.033).
The AFSS symptom score (range 0-35) indicates how bothered subjects are by palpitations, shortness of breath at rest and during physical activity, exercise intolerance, fatigue at rest, lightheadedness and chest pain/pressure. The AFSS burden subscale (range 3 to 30) is the sum of frequency, duration and severity of AF episodes. Higher scores on both scales indicate worse symptoms or burden. AFSS global well-being was assessed with a visual analog scale rating how the subject feels about his/her life (1=worst possible; 10=best possible). The symptom trajectory for the intervention group showed significantly improved ratings of AF symptoms (M=11.3 vs. 5.8, p=.005) and global well-being (M=6.5 vs. 7.6, p=.003) between baseline and three months. There were no significant changes in AF burden, symptoms, severity or global well-being in the usual care group over time. Group comparisons showed that the intervention subjects had significantly worse AF burden scores at baseline (M=18.8 vs. 12.4, p=.030) and six months (M=15.1 vs. 9.5, p=.011); and worse AF severity at six months (M=5.8 vs. 2.8, p=.003) than usual care subjects. No significant differences between groups were found for health care utilization by number of emergency room visits, hospitalizations and specialist visits in the year prior to study enrollment.
AF-specific quality of life was measured with the AFEQT overall and subscale scores (range 0 to 100; extreme to minimal disability/difficulty). For the intervention group, the HRQOL trajectory showed improvement in overall AFEQT scores (M=60.8 vs. 80.1; p=.001) and three of the four subscales for daily activities, treatment concerns and treatment satisfaction between T1 and T2. No significant changes in AFEQT scores were found for the usual care group at any time point. AFEQT meaningful important improvement scores were examined as described by Dorian et al. (2013), in which a 19-point or greater change indicates a substantial improvement in quality of life (p.385). Between baseline and 3-months, 61% (11/18) of intervention subjects were found to have a meaningful improvement. No meaningful improvements in quality of life were found for usual care subjects between time periods. Group comparisons showed that the intervention subjects reported significantly worse treatment concern scores than the control group at baseline (M=59.5 vs. 85.3, p=.029). Treatment concern items rate how worried or anxious the subject feels about their AF starting at any time, worsening other medical conditions and worry about medication and treatment side effects. Except for the treatment concern subscale, no statistically significant differences for overall AFEQT, AF symptoms, daily activities and treatment satisfaction were found between groups at any time period.
Limitations: One important limitation was the small sample size, especially in the usual care group. However, referral and participation rates were consistent with the anticipated number of eligible patients at this site. No sample size calculation had been planned for the pilot study.
Conclusion: The results of this study confirmed that many patients with a primary diagnosis of symptomatic AF often present with multiple cardiometabolic risk factors. While usual care providers are aware of the need to address lifestyle modifications, office time is limited and typically focuses on medical management issues. Referring appropriate patients to a community-based cardiac rehabilitation program significantly improved AF symptoms, symptom burden, daily activities, treatment concerns, treatment satisfaction, global well-being and AF-related quality of life for the intervention group. A recent study by Dorian and colleagues (2013) found a meaningful important improvement in overall HRQOL in 35% of patients after three months of usual care treatment. With the addition of the cardiac rehabilitation intervention in our study, 61% of subjects with similar baseline characteristics reported a meaningful improvement in HRQOL over the same time period. The advantages for patients to participate in cardiac rehabilitation include the repetitive interaction with and coaching by skilled nurses and clinicians who specialize in exercise therapy, dietary modification, stress management and self-care strategies (AACVPR, 2013).
These results also suggest that patients with AF who voluntarily participate in a 12-week cardiac rehabilitation program may present with unique characteristics such as being relatively younger, experienced cardioversion, had worse treatment concerns and reported greater disease burden related to frequency, duration and severity of AF episodes. Future research aimed at identifying patients with symptomatic AF who may benefit the most from cardiac rehabilitation would be useful to nurses and other clinicians who regularly care for these patients. This pilot study also suggests that strategies to sustain improvement in HRQOL beyond the cardiac rehabilitation intervention are still needed.