EURO PEAN SO CIETY O F CARDIOLOGY ®
Original scientific paper
Adults with complex congenital heart disease have impaired skeletal muscle function and reduced confidence in performing exercise training
European Journal of Preventive Cardiology 2015, Vol. 22(12) 1523–1530 ! The European Society of Cardiology 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/2047487314543076 ejpc.sagepub.com
Camilla Sandberg1, Ulf Thile´n2, Karin Wadell3 and Bengt Johansson1
Abstract Background: Adults with congenital heart disease (ACHD) usually have reduced aerobic exercise capacity compared with controls. However, their skeletal muscle function is less studied. Material and methods: In this cross-sectional study, unilateral isotonic shoulder flexion, unilateral isotonic heel-lift, maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were tested in 85 patients with ACHD (35 women, mean age 36.8 14.8 years), classed as either ‘complex’ (n ¼ 43) or ‘simple’ (n ¼ 42), and 42 age and gender matched controls (16 women, mean age 36.9 14.9). Maximum number of shoulder flexions and heel-lifts were measured. MIP/MEP was tested using a handheld respiratory pressure meter. Exercise self-efficacy, measuring confidence in performing exercise training, was evaluated. Results: Adults with complex lesions performed fewer shoulder flexions compared with controls and patients with simple lesions (28.2 11.1 vs. 63.6 40.4, p < 0.001 and 28.2 11.1 vs. 54.9 24.9, p < 0.001), as well as fewer heel-lifts compared with controls and patients with simple lesions (17.6 7.7 vs. 26.3 12.8, p < 0.001 and 17.6 7.7 vs. 23.2 7.0, p ¼ 0.024), lower MIP than controls (80.7 26.7 vs. 111.1 29.9 cm H2O, p < 0.001) and lower MEP compared with controls (110.8 39.9 vs. 141.8 39.5, p < 0.001). Their exercise self-efficacy was lower than controls (28.0 8.3 vs. 33.4 6.1, p ¼ 0.002). In a linear regression model complex heart lesions were independently associated with impaired limb muscle function. Conclusion: Adults with complex congenital heart disease have impaired skeletal muscle function compared with patients with simple lesions and healthy controls. They also had lower confidence in performing exercise training. Thus, this population might have a potential for rehabilitation focusing on improving muscle function and confidence in performing exercise training.
Keywords Muscle function, congenital heart disease, exercise self-efficacy Received 17 April 2014; accepted 20 June 2014
Introduction Thanks to advances in surgical and medical treatment, the majority of children born with a congenital heart disease reach adulthood. As a consequence, adults with complex congenital heart disease outnumber the children with corresponding lesions.1 Potential long-term complications in the different lesions are not fully known and will probably change as new treatment strategies are introduced.2 A majority of patients with congenital heart disease, irrespective of lesion, have
1 Heart Centre and Department of Public Health and Clinical Medicine, Umea˚ University, Sweden 2 Department of Cardiology, Clinical Sciences, Lund University, Sweden 3 Department of Community Medicine and Rehabilitation, Physiotherapy, Umea˚ University, Sweden
Corresponding author: Bengt Johansson, Cardiology, Heart Centre, Umea˚ University Hospital, SE-90185, Umea˚, Sweden. Email: [email protected]
Downloaded from cpr.sagepub.com at University of Otago Library on November 14, 2015
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European Journal of Preventive Cardiology 22(12)
impaired exercise capacity compared with healthy controls. Patients with more complex lesions, for example a previous Fontan or a total cavo-pulmonary connection (TCPC) operation, are even more limited in their exercise capacity.3 Previous studies have shown a correlation between decreased exercise capacity, impaired respiratory muscle function and handgrip strength in patients with a Fontan circulation.4,5 Furthermore patients with a Fontan circulation have reduced skeletal muscle mass and impaired muscle aerobic capacity measured in calf muscles.6 In a cohort of adults with a variety of congenital heart lesions, no difference in grip strength was demonstrated when compared with a reference population while isotonic limb muscle function was reduced compared with controls. The reference population for these latter tests were, however, substantially older, which may have influenced the results.7 Previous studies on the physical activity level in adults with different congenital heart lesions have shown that a majority did not reach the recommendations on daily physical activity.8,9 An association between level of physical activity and health related quality of life has been reported10 and an evaluation of confidence in performing physical activities showed a willingness to exercise and to be physically active if properly instructed.11 In contrast, a majority (72%) of a mixed population consisting of both children and adults (8–52 years) with univentricular hearts and TCPC reached the recommendations of daily physical activity.12 However, the study included only few subjects above the age of 20. As recommendations for daily physical activity differ between children and adults13 it is mandatory to have data originating from a relevant population to give proper advice to patients. Therefore, we include only adults at various ages. Muscle function is an important part of general physical functioning but is poorly studied in adults with congenital heart disease and is generally not compared with age and gender matched reference populations.5,7 Furthermore, the confidence in preforming physical exercise – the exercise self-efficacy – among adults with congenital heart disease has been studied only within populations with congenital heart disease9,11 and not previously been compared with a reference population. Of special interest is the relation between the confidence in performing physical exercise and muscle function since both are potential targets for rehabilitation therapies. The aim of the present study was thus to examine muscle function, in respiratory and limb skeletal muscles, and the confidence in performing physical exercise in adult patients with different congenital heart lesions and to compare with an age- and gender-matched reference population. We also aimed to investigate factors associated with impaired muscle function.
Material and methods Patients and controls Eighty-five adults with congenital heart disease were included from the university hospital centres for adult congenital heart disease in Umea˚ and Lund. The inclusion criteria were: periodic out-patient medical visits for congenital heart disease and clinically stable condition over the past three months. The exclusion criteria were: intellectual disability or mental illness affecting independent decision-making, extra-cardiac disease affecting physical activity or other circumstances making participation unsuitable. One hundred and thirteen patients were asked to participate, 23 denied participation and five did not appear at the clinical visit. Eightyfive patients participated and 83 of these performed complete muscle function tests (maximum inspiratory pressure (MIP)/maximum expiratory pressure (MEP) test n ¼ 85, shoulder flexion test n ¼ 84, heel-lift test n ¼ 84). To achieve a balanced diversity of diagnoses and complexity, as the simple lesions are much more common, patients were recruited into four different groups based on diagnosis ((i) shunt lesions, (ii) left sided lesions, (iii) repaired tetralogy of Fallot/transposition of the great arteries (TGA) and (iv) Eisenmenger/ Fontan/TCPC/other complex lesions) until the group comprised at least 20 patients with complete data. Groups (i) and (ii) were classed as ‘simple’ and (iii) and (iv) as ‘complex’ (Table 1). Forty-two age- and gender-matched controls (no congenital heart disease or any exclusion criteria presented above) living in the Umea˚ area were randomly recruited via the national population registry. One hundred and twenty-nine individuals had been asked to participate as controls (73 men, 56 women), of whom 86 persons declined participation (47 men, 39 women) and one did not appear at clinical visit. The reason for declining was not specifically asked for. Descriptive data of included patients and controls are presented in Table 2. Medications were more frequent in patients with complex lesions versus both simple lesions (p ¼ 0.006) and controls (p < 0.001) but there were no differences between simple lesions and controls. All patients and controls gave their written informed consent for participation. The study was approved by the regional Ethics Review Board (Dnr 2011-51-31 M, 2011).
Muscle function tests Unilateral isotonic shoulder flexion. The subjects were sitting comfortably with their back touching the wall and holding a weight (2 kg for women and 3 kg for men) in the hand of the dominant side. The patients were asked to elevate the arm, from 0 to 90 flexion, as
Downloaded from cpr.sagepub.com at University of Otago Library on November 14, 2015
Sandberg et al.
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Table 1. Distribution of heart lesions and classification into simple or complex lesion. Simple lesion:
n ¼ 42
Complex lesion:
n ¼ 43
CoA AS AR AS/AR VSD ASD PFO PDA MR
12 3 3 4 15 2 1 1 1
d-TGA (atrial switch) ccTGA ToF PA DORV DILV (no intervention) TCPC Atrio-pulmonary Fontan Ebstein Eisenmenger Miscellaneous
5 2 9a 3 2 1 9 2 3 6 1
a Among the patients with ToF, seven had no or mild residual pulmonary regurgitation (PR) and two had severe PR. CoA: coarctation of the aorta; AS: aortic stenosis; AR: aortic regurgitation; VSD: ventricular septal defect; ASD: atrial septal defect; PFO: persistent foramen ovale; PDA: persistent ductus arteriosus; MR: mitral regurgitation; d-TGA: d-transposition of the great arteries; ccTGA: congenitally corrected transposition of the great arteries; ToF: tetralogy of Fallot; PA: pulmonary atresia; DORV: double outlet of right ventricle; DILV: double inlet left ventricle; TCPC: total cavo-pulmonary connection.
many times as possible in a frequency of 20 repetitions per minute following a metronome (KORG metronome MA-30, KORG Inc., Japan). The maximum number of shoulder flexions was registered.14 Unilateral isotonic heel-lift. The test person stood on one leg on a 10 tilted wedge touching the wall with the fingertips for balance. The contralateral foot was held slightly above the floor. The test persons were asked to perform as many heel-lifts as possible with a frequency of 30 repetitions per minute following a metronome (KORG Inc., Japan). They were instructed to touch a marker on a measuring stick with their head on every heel-lift. The position of marker was individually adjusted before testing. The maximum number of heel-lifts was registered.14 The participants were instructed to perform the muscle function tests with maximum effort. No additional encouragement during the tests was used in order to ensure standardization.14 Respiratory muscle function. The tests of MIP and MEP were performed with the test person sitting on a chair. MIP and MEP were measured using a hand-held respiratory pressure meter (Micro RPMTM, CareFusion, San Diego, CA, USA). When measuring MIP, the test person was instructed to perform a maximum exhalation, put the instrument mouthpiece into the mouth and then perform a maximum inhalation.
MEP was measured after maximum inhalation followed by a maximum exhalation. During the tests, the nose was closed by a soft clip to prevent nasal inhalation/exhalation. The highest pressure achieved (cm H2O) in one out of three tests was used for analysis. The reliability of Micro RPMTM has been validated on healthy subjects.15 The Exercise Self-efficacy Scale. All participants completed the exercise self-efficacy (ESE) questionnaire, consisting of 10 items, on a four-point Likert scale, related to confidence in performing exercise.16 A score ranging from 10 to 40 was calculated where 40 denotes best possible ESE. The Swedish version has recently been validated (personal communication).
Statistics All calculations were performed using SPSS 20 (IBM, Armonk, NY, USA). The data were tested for normality. Unless otherwise stated, data are presented as means 1 standard deviation (SD). Differences in means, medians and ratios were tested by one-way analysis of variance (ANOVA), Kruskal–Wallis test or multifrequency cross-tables. In post-hoc mode, Student’s t-test, Mann–Whitney U-test or chi-square test were used as appropriate. For multiple-group comparisons, the Bonferroni correction was applied. The effect of variables was tested by univariate and multivariate linear regression versus measures of limb muscle function, run in a manual backward mode. Variables with p-values
Original scientific paper
Adults with complex congenital heart disease have impaired skeletal muscle function and reduced confidence in performing exercise training
European Journal of Preventive Cardiology 2015, Vol. 22(12) 1523–1530 ! The European Society of Cardiology 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/2047487314543076 ejpc.sagepub.com
Camilla Sandberg1, Ulf Thile´n2, Karin Wadell3 and Bengt Johansson1
Abstract Background: Adults with congenital heart disease (ACHD) usually have reduced aerobic exercise capacity compared with controls. However, their skeletal muscle function is less studied. Material and methods: In this cross-sectional study, unilateral isotonic shoulder flexion, unilateral isotonic heel-lift, maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were tested in 85 patients with ACHD (35 women, mean age 36.8 14.8 years), classed as either ‘complex’ (n ¼ 43) or ‘simple’ (n ¼ 42), and 42 age and gender matched controls (16 women, mean age 36.9 14.9). Maximum number of shoulder flexions and heel-lifts were measured. MIP/MEP was tested using a handheld respiratory pressure meter. Exercise self-efficacy, measuring confidence in performing exercise training, was evaluated. Results: Adults with complex lesions performed fewer shoulder flexions compared with controls and patients with simple lesions (28.2 11.1 vs. 63.6 40.4, p < 0.001 and 28.2 11.1 vs. 54.9 24.9, p < 0.001), as well as fewer heel-lifts compared with controls and patients with simple lesions (17.6 7.7 vs. 26.3 12.8, p < 0.001 and 17.6 7.7 vs. 23.2 7.0, p ¼ 0.024), lower MIP than controls (80.7 26.7 vs. 111.1 29.9 cm H2O, p < 0.001) and lower MEP compared with controls (110.8 39.9 vs. 141.8 39.5, p < 0.001). Their exercise self-efficacy was lower than controls (28.0 8.3 vs. 33.4 6.1, p ¼ 0.002). In a linear regression model complex heart lesions were independently associated with impaired limb muscle function. Conclusion: Adults with complex congenital heart disease have impaired skeletal muscle function compared with patients with simple lesions and healthy controls. They also had lower confidence in performing exercise training. Thus, this population might have a potential for rehabilitation focusing on improving muscle function and confidence in performing exercise training.
Keywords Muscle function, congenital heart disease, exercise self-efficacy Received 17 April 2014; accepted 20 June 2014
Introduction Thanks to advances in surgical and medical treatment, the majority of children born with a congenital heart disease reach adulthood. As a consequence, adults with complex congenital heart disease outnumber the children with corresponding lesions.1 Potential long-term complications in the different lesions are not fully known and will probably change as new treatment strategies are introduced.2 A majority of patients with congenital heart disease, irrespective of lesion, have
1 Heart Centre and Department of Public Health and Clinical Medicine, Umea˚ University, Sweden 2 Department of Cardiology, Clinical Sciences, Lund University, Sweden 3 Department of Community Medicine and Rehabilitation, Physiotherapy, Umea˚ University, Sweden
Corresponding author: Bengt Johansson, Cardiology, Heart Centre, Umea˚ University Hospital, SE-90185, Umea˚, Sweden. Email: [email protected]
Downloaded from cpr.sagepub.com at University of Otago Library on November 14, 2015
1524
European Journal of Preventive Cardiology 22(12)
impaired exercise capacity compared with healthy controls. Patients with more complex lesions, for example a previous Fontan or a total cavo-pulmonary connection (TCPC) operation, are even more limited in their exercise capacity.3 Previous studies have shown a correlation between decreased exercise capacity, impaired respiratory muscle function and handgrip strength in patients with a Fontan circulation.4,5 Furthermore patients with a Fontan circulation have reduced skeletal muscle mass and impaired muscle aerobic capacity measured in calf muscles.6 In a cohort of adults with a variety of congenital heart lesions, no difference in grip strength was demonstrated when compared with a reference population while isotonic limb muscle function was reduced compared with controls. The reference population for these latter tests were, however, substantially older, which may have influenced the results.7 Previous studies on the physical activity level in adults with different congenital heart lesions have shown that a majority did not reach the recommendations on daily physical activity.8,9 An association between level of physical activity and health related quality of life has been reported10 and an evaluation of confidence in performing physical activities showed a willingness to exercise and to be physically active if properly instructed.11 In contrast, a majority (72%) of a mixed population consisting of both children and adults (8–52 years) with univentricular hearts and TCPC reached the recommendations of daily physical activity.12 However, the study included only few subjects above the age of 20. As recommendations for daily physical activity differ between children and adults13 it is mandatory to have data originating from a relevant population to give proper advice to patients. Therefore, we include only adults at various ages. Muscle function is an important part of general physical functioning but is poorly studied in adults with congenital heart disease and is generally not compared with age and gender matched reference populations.5,7 Furthermore, the confidence in preforming physical exercise – the exercise self-efficacy – among adults with congenital heart disease has been studied only within populations with congenital heart disease9,11 and not previously been compared with a reference population. Of special interest is the relation between the confidence in performing physical exercise and muscle function since both are potential targets for rehabilitation therapies. The aim of the present study was thus to examine muscle function, in respiratory and limb skeletal muscles, and the confidence in performing physical exercise in adult patients with different congenital heart lesions and to compare with an age- and gender-matched reference population. We also aimed to investigate factors associated with impaired muscle function.
Material and methods Patients and controls Eighty-five adults with congenital heart disease were included from the university hospital centres for adult congenital heart disease in Umea˚ and Lund. The inclusion criteria were: periodic out-patient medical visits for congenital heart disease and clinically stable condition over the past three months. The exclusion criteria were: intellectual disability or mental illness affecting independent decision-making, extra-cardiac disease affecting physical activity or other circumstances making participation unsuitable. One hundred and thirteen patients were asked to participate, 23 denied participation and five did not appear at the clinical visit. Eightyfive patients participated and 83 of these performed complete muscle function tests (maximum inspiratory pressure (MIP)/maximum expiratory pressure (MEP) test n ¼ 85, shoulder flexion test n ¼ 84, heel-lift test n ¼ 84). To achieve a balanced diversity of diagnoses and complexity, as the simple lesions are much more common, patients were recruited into four different groups based on diagnosis ((i) shunt lesions, (ii) left sided lesions, (iii) repaired tetralogy of Fallot/transposition of the great arteries (TGA) and (iv) Eisenmenger/ Fontan/TCPC/other complex lesions) until the group comprised at least 20 patients with complete data. Groups (i) and (ii) were classed as ‘simple’ and (iii) and (iv) as ‘complex’ (Table 1). Forty-two age- and gender-matched controls (no congenital heart disease or any exclusion criteria presented above) living in the Umea˚ area were randomly recruited via the national population registry. One hundred and twenty-nine individuals had been asked to participate as controls (73 men, 56 women), of whom 86 persons declined participation (47 men, 39 women) and one did not appear at clinical visit. The reason for declining was not specifically asked for. Descriptive data of included patients and controls are presented in Table 2. Medications were more frequent in patients with complex lesions versus both simple lesions (p ¼ 0.006) and controls (p < 0.001) but there were no differences between simple lesions and controls. All patients and controls gave their written informed consent for participation. The study was approved by the regional Ethics Review Board (Dnr 2011-51-31 M, 2011).
Muscle function tests Unilateral isotonic shoulder flexion. The subjects were sitting comfortably with their back touching the wall and holding a weight (2 kg for women and 3 kg for men) in the hand of the dominant side. The patients were asked to elevate the arm, from 0 to 90 flexion, as
Downloaded from cpr.sagepub.com at University of Otago Library on November 14, 2015
Sandberg et al.
1525
Table 1. Distribution of heart lesions and classification into simple or complex lesion. Simple lesion:
n ¼ 42
Complex lesion:
n ¼ 43
CoA AS AR AS/AR VSD ASD PFO PDA MR
12 3 3 4 15 2 1 1 1
d-TGA (atrial switch) ccTGA ToF PA DORV DILV (no intervention) TCPC Atrio-pulmonary Fontan Ebstein Eisenmenger Miscellaneous
5 2 9a 3 2 1 9 2 3 6 1
a Among the patients with ToF, seven had no or mild residual pulmonary regurgitation (PR) and two had severe PR. CoA: coarctation of the aorta; AS: aortic stenosis; AR: aortic regurgitation; VSD: ventricular septal defect; ASD: atrial septal defect; PFO: persistent foramen ovale; PDA: persistent ductus arteriosus; MR: mitral regurgitation; d-TGA: d-transposition of the great arteries; ccTGA: congenitally corrected transposition of the great arteries; ToF: tetralogy of Fallot; PA: pulmonary atresia; DORV: double outlet of right ventricle; DILV: double inlet left ventricle; TCPC: total cavo-pulmonary connection.
many times as possible in a frequency of 20 repetitions per minute following a metronome (KORG metronome MA-30, KORG Inc., Japan). The maximum number of shoulder flexions was registered.14 Unilateral isotonic heel-lift. The test person stood on one leg on a 10 tilted wedge touching the wall with the fingertips for balance. The contralateral foot was held slightly above the floor. The test persons were asked to perform as many heel-lifts as possible with a frequency of 30 repetitions per minute following a metronome (KORG Inc., Japan). They were instructed to touch a marker on a measuring stick with their head on every heel-lift. The position of marker was individually adjusted before testing. The maximum number of heel-lifts was registered.14 The participants were instructed to perform the muscle function tests with maximum effort. No additional encouragement during the tests was used in order to ensure standardization.14 Respiratory muscle function. The tests of MIP and MEP were performed with the test person sitting on a chair. MIP and MEP were measured using a hand-held respiratory pressure meter (Micro RPMTM, CareFusion, San Diego, CA, USA). When measuring MIP, the test person was instructed to perform a maximum exhalation, put the instrument mouthpiece into the mouth and then perform a maximum inhalation.
MEP was measured after maximum inhalation followed by a maximum exhalation. During the tests, the nose was closed by a soft clip to prevent nasal inhalation/exhalation. The highest pressure achieved (cm H2O) in one out of three tests was used for analysis. The reliability of Micro RPMTM has been validated on healthy subjects.15 The Exercise Self-efficacy Scale. All participants completed the exercise self-efficacy (ESE) questionnaire, consisting of 10 items, on a four-point Likert scale, related to confidence in performing exercise.16 A score ranging from 10 to 40 was calculated where 40 denotes best possible ESE. The Swedish version has recently been validated (personal communication).
Statistics All calculations were performed using SPSS 20 (IBM, Armonk, NY, USA). The data were tested for normality. Unless otherwise stated, data are presented as means 1 standard deviation (SD). Differences in means, medians and ratios were tested by one-way analysis of variance (ANOVA), Kruskal–Wallis test or multifrequency cross-tables. In post-hoc mode, Student’s t-test, Mann–Whitney U-test or chi-square test were used as appropriate. For multiple-group comparisons, the Bonferroni correction was applied. The effect of variables was tested by univariate and multivariate linear regression versus measures of limb muscle function, run in a manual backward mode. Variables with p-values
