Effects of a Comprehensive Rehabilitation Program on Quality of Life in Patients With Chronic Heart Failure

Katharina Meyer, PhD, MPH, Kurt Laederach-Hofmann, MD

Disclosures

Prog Cardiovasc Nurs. 2003;18(4) 

In This Article

Discussion

Chronic heart failure has a major effect on patients' lives and on their families' lives. Therefore, there is a need for professional instruction and support, which could be offered by integrated multidisciplinary care; for example, by means of a comprehensive outpatient rehabilitation program.

Initially, our patients demonstrated severely reduced left ventricular systolic function. Functional capacity (NYHA classification, peak power output, absolute and relative peak oxygen uptake, and oxygen uptake at ventilatory threshold) was moderately impaired compared with reference measures.[19] A 6-minute walking distance less than <300 meters on average was demonstrated to correspond to considerable functional impairment[20,21] and predicted poor prognosis[19] ( Table I ).

The magnitude of improvement of peak exercise capacity ( Table I ) was similar to that obtained in exercise training studies[9,21,22,23,24] and was similar to and/or greater than improvements reported in drug studies on β blocker (11%),[8] ACE inhibitor (9%),[22] and ACE inhibitor plus nitrates (27%)[25] in heart failure patients with NYHA functional class II and III. When treatment with an ACE inhibitor was provided in combination with exercise training, a cumulative improvement in peak exercise time and peak oxygen uptake could be achieved with an additional increase of 12%.[22] Due to the relatively short 12-week rehabilitation period, the maximum possible improvement in exercise capacity might not have been exhausted Keteyian et al.,[23] for example, demonstrated increasing adaptation up to 6 months.

The SF-36 and MLHFQ have been validated for reliability, validity, and responsiveness in English-[17] and in German-speaking[15] chronic heart failure patients as generic and disease-specific questionnaires, respectively. Our patient sample was similar to those in Rector et al.'s[14] original study.

According to accepted international psychometric research, SF-36 values exceeding 60 correspond to high quality of life and values below 40 represent reduced quality of life. Before and at the end of rehabilitation, 75% of our patients demonstrated non-age- and gender-adjusted SF-36 scores within or above the normative value of between 40 and 60 ( Table II ).[15]

However, compared with the German heart failure reference sample, our patients demonstrated lower mean scores for role functioning (score values 27.1 vs. 48.1 [representing 56.3% of the normative sample]), pain (28.9 vs. 50.7 [57% of the normative sample]), social functioning (50.0 vs. 74.1 [67.5%]), emotional functioning (62.1 vs. 72.9, [85.2%]), and mental health (59.0 vs. 62.9, [85.2%]) but higher scores for general health perception (65.7 vs. 42.1 [156%]), and vitality (52.5 vs. 45.2, [115.5%]) ( Table II ). Perception of physical role functioning, and pain on average, was severely impaired but demonstrated a great variance. In terms of emotional functioning, three fourths of patients showed no impairment when compared with healthy subjects ( Table II ).[13,15]

In our patients, perception of physical functioning, general health and vitality, and pain contrasted to results reported by Quittan et al.[26] who used the SF-36 as an exercise training outcomes measure. In their study, pain did not seem to limit quality of life, whereas in our patients it obviously did ( Table II ). The reason for this remains obscure and might be associated with the differing severity of disease in the patients assessed.

After the 12-week comprehensive rehabilitation program, the SF-36 revealed significant improvements in only two physical and one mental score ( Table III ), whereas Quittan et al.[26] achieved improvements in six out of eight scales after 12 weeks of exercise training. In our patients, it is striking that peak exercise capacity improved significantly ( Table I ) while physical component score did not ( Table III ). Improvement in the physical functioning subscale, which explicitly asks about physical activities such as walking, climbing stairs, and lifting loads, did not show significant correlation to improvement in exercise capacity. The inconsistency of these results might be explained by the assertion by Bullinger et al[15] that due to formulation of items close to a subjects' behavior, the SF-36 scale does not consider the relative importance of impairment for an individual patient very well. This indicates that generic questionnaires seem to have limitations in their ability to measure changes in quality of life in chronic heart failure patients.

At baseline, MLHFQ mean sum score indicated moderate impairment in quality of life (Figure). The sum score was similar to the sum score reported for a US and a German heart failure reference population of NYHA class II and class III patients.[17,26] Similar to results reported by Quittan et al.,[18] in our patients the baseline MLHFQ sum score of 27.7 on average corresponded to NYHA functional class II, and an average sum score of 42.7 to class III ( Table IV ).

Twelve weeks of rehabilitation resulted in improvements in MLHFQ sum score (29% on average), and in physical component score (37% on average) (Figure). Small but significant effect sizes (p<0.50) were found in both scores, indicating a consistent but low grade of improvement. In previous studies, improvements of 30%, 37%, and 22% on average for MLHFQ sum score, physical component score, and emotional component score, respectively, were reported after 2 and 14 months of exercise training. In a study by Wilson et al.,[27] MLHFQ sum score only was improved by 30% after 2 months of exercise training in patients who were responders in terms of increased peak oxygen uptake. In double-blind, multicenter pharmaceutical trials including NYHA class II and III patients, 1 to 18 months of treatment with a calcium antagonist,[28] a β blocker, 8 an ACE inhibitor, 22 or an ACE inhibitor plus nitrate[25] resulted in improvements in the MLHFQ sum score by 8%-18% on average, which was markedly smaller than our results.

Oxygen uptake at ventilatory threshold in percentage of predicted maximum oxygen uptake is a marker of submaximum exercise intolerance and thus was used for half-split methods to determine NYHA classification, 6-minute walking distance, and quality of life. The split half groups did not differ with respect to age, ejection fraction, and NYHA classes, but MLHFQ emotional component score was significantly lower in the patients with lower exercise capacity ( Table V ). Our results indicate positive effects on quality-of-life factors even in the relatively short period of 12 weeks. However, improvements do not only show amelioration, but also a deterioration. Patients with severe impairment may, paradoxically, judge their emotional status as better in cognitive tests (e.g., using MLHFQ) than patients who objectively were less impaired, a well-known finding in other chronic disease states.[29] However, at the end of the rehabilitation program, patients with initially lower emotional component scores rated relatively higher than the counter group, indicating a more realistic judgment of their emotional state. A similar tendency was seen in SF-36 general health perception. Here, patients with major physical impairment also demonstrated higher initial SF-36 vitality scores, indicating a false initial perception and the ability to rate vitality more realistically at the end of the rehabilitation program ( Table V ). This finding high-lights personality traits of cardiac patients such as pseudoindependence,[30] a tendency to deny the severity of the disease, and suppressing emotional distress.[31] In this context, the psychological intervention might have lead to a more realistic appraisal of the severity of disease in our patients.

Correlations between somatic variables and items of generic or disease-specific questionnaires were generally weak. In our study, two of the four significant correlations were demonstrated to be negative, and two were positive, including the disease-specific quality-of-life score ( Table VI ) and dyspnea, which showed linear correlation to diaphragmatic work.[32] Other authors have found significant correlations between exercise time, anaerobic threshold, and quality of life[33] with no improvement of peak oxygen uptake. In this study, however, no positive effect of the exercise training was detected in patients with limited exercise capacity.

With the exception of the clinical inclusion criteria, assignment to the rehabilitation group was based on the physicians' decision with respect to clinical, physical, and/or psychosocial indications. These indications have not been analyzed.

One year after the rehabilitation program was started it was evaluated on the basis of prospective data. Because it was a pilot program, a control group was not established. The objective of this observational study was not to delineate the different contributions of the effects of medication, physical training, and counseling as reported in other clinical studies. Instead, our study aimed at evaluating the gross effect of an integrated and comprehensive routine rehabilitation program in nonselected heart failure patients. Our findings on quality of life have limitations. The small number of patients responding to the questionnaires may not be truly representative of stable patients with chronic heart failure who are suitable for a program as presented in this study. There may be bias in the sample because respondents were patients who were willing to focus on and share their feelings.

Due to the small sample size it was not possible to study the interaction of changes in quality-of-life variables and potentially relevant socioeconomic characteristics (e.g., living alone or with partner/family, lower vs. higher social class). Thus, for future studies, a multicenter approach that allows the assessment of the influence of socioeconomic characteristics is recommended. Additionally, it is of interest which factors (exercise capacity, drug treatment, patients' compliance, psychoemotional support) contribute more or less to improvement of quality of life.

In patients with NYHA class II and III chronic heart failure, even 12 weeks of a comprehensive outpatient rehabilitation program resulted in an improvement of exercise capacity and dimensions of quality of life. In both, the magnitude of improvement was similar to the improvement achieved by exercise training studies. However, improvement of disease-specific quality of life was stronger than reported from drug studies. For evaluation of intervention-induced effects on quality of life, the disease-specific MLHFQ was demonstrated to be clearly superior.

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