Elisabeth Bø, Series of dissertations submitted to the Faculty of Medicine, University of Oslo No ISBN - PDF

Elisabeth Bø, 2014 Series of dissertations submitted to the Faculty of Medicine, University of Oslo No ISBN All rights reserved. No part of this publication may be reproduced or

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Elisabeth Bø, 2014 Series of dissertations submitted to the Faculty of Medicine, University of Oslo No ISBN All rights reserved. No part of this publication may be reproduced or transmitted, in any form or by any means, without permission. Cover: Inger Sandved Anfinsen. Printed in Norway: AIT Oslo AS. Produced in co-operation with Akademika Publishing. The thesis is produced by Akademika Publishing merely in connection with the thesis defence. Kindly direct all inquiries regarding the thesis to the copyright holder or the unit which grants the doctorate. I II III Int. J. Environ. Res. Public Health 2013, 10, ; doi: /ijerph OPEN ACCESS Article International Journal of Environmental Research and Public Health ISSN Twelve-Months Follow-up of Supervised Exercise after Percutaneous Transluminal Angioplasty for Intermittent Claudication: A Randomised Clinical Trial Elisabeth Bø 1,2, *, Jonny Hisdal 3, Milada Cvancarova 1, Einar Stranden 2,3, Jørgen J. Jørgensen 2,4, Gunnar Sandbæk 2,5, Ole J. Grøtta 5 and Astrid Bergland Faculty of Health Sciences, Oslo and Akershus University, Pilestredet 46, 0130 Oslo, Norway; s: (M.C.); (A.B.) Faculty of Medicine, University of Oslo, Klaus Torgårdsvei 3, 0372 Oslo, Norway; s: (E.S.); (J.J.J.); (G.S.) Section of Vascular Investigations, Oslo Vascular Centre, Oslo University Hospital Aker, Trondheimsveien 235, 0586 Oslo, Norway; Department of Vascular Surgery, Oslo Vascular Centre, Oslo University Hospital Aker, Trondheimsveien 235, 0586 Oslo, Norway Department of Radiology and Nuclear Medicine, Oslo University Hospital Aker, Trondheimsveien 235, 0586 Oslo, Norway; * Author to whom correspondence should be addressed; Tel.: Received: 29 August 2013; in revised form: 4 November 2013 / Accepted: 6 November 2013 / Published: 11 November 2013 Abstract: The aim of this study was to explore the effects during 12 months follow-up of 12 weeks of supervised exercise therapy (SET) after percutaneous transluminal angioplasty (PTA) compared to PTA alone on physical function, limb hemodynamics and health-related quality of life (HRQoL) in patients with intermittent claudication. Fifty patients were randomised to an intervention or a control group. Both groups received usual post-operative care and follow-up measurements at three, six and 12 months after PTA. The intervention group performed 12 weeks of SET after PTA. The control group did not receive any additional follow-up regarding exercise. During the 12 months follow-up, the members of the intervention group had significantly better walking distance than the control group. The intervention group had a significantly higher HRQoL score in the physical component Int. J. Environ. Res. Public Health 2013, score of the SF-36, and the domains of physical function, bodily pain and vitality. For limb hemodynamics, there was a non-significant trend towards better results in the intervention group compared to the control group. Conclusion: SET after PTA yielded statistically significantly better results for walking distance and HRQoL in the intervention group than the control group during the 12 months of follow-up. Keywords: exercise; PTA; intermittent claudication; follow-up; randomised clinical trial 1. Introduction Peripheral arterial disease (PAD) is a condition where atherosclerotic plaques build up in the arteries. With time, the size of the plague might increase and narrow the lumen of the arteries, consequently limiting the blood flow distal to the affected arterial segment. This flow limitation may cause pain during activity, which is relieved with rest. These symptoms are called intermittent claudication, and they affect approximately 30% of the patients with PAD. PAD itself is present in approximately 20% of people older than 65 years and it increases with age [1]. Because of its high prevalence, high rate of nonfatal cardiovascular ischemic events, high risk of mortality and reduction of quality of life the consequences of PAD are significant [2]. The treatment aim of PAD is to reduce symptoms, improve quality of life and physical function, and prevent further progression and complications. Treatment strategies include lifestyle changes like smoking cessation, exercise, medication and, if necessary, revascularisation, either endovascular or by surgery [1,3,4]. As there is no definitive cure for PAD, prevention of further progression of the disease is of great importance. Previous research and clinical experience have identified several effective treatment options [5 8]. However, the best treatment in terms of costs, the intensity and frequency of the intervention, and the length of health professionals involvement is not known [9]. The scarce knowledge on enabling patients to be independent and master their own everyday lives including management of a life-long disease, are also important factors as to why research is still needed in this field [10]. Authors have suggested the relatively new treatment option of supervised exercise training (SET) after percutaneous transluminal angioplasty (PTA) as an important topic for future research [11 13]. The possible advantage of adding SET after PTA is the twofold focus on locally increased blood flow during activity in the treated area and the general effects of exercise, which also influence general risk factor development for further manifestation of cardiovascular disease. However, little is known about the effects of SET after PTA for PAD, particularly for longer-term follow-up. To our knowledge, only two studies on SET following PTA have previously been reported [14,15]. Mazari et al. [15] used a three-month training intervention, and reported statistically significant improvements in walking distance at three months for all the studied treatment arms (PTA alone, SET alone and PTA+SET) with the PTA+SET group performing better than either treatment alone. At 12 months of follow-up, this advantage was not sustained. For HRQoL, statistically significant improvements were reported throughout the 12-month follow-up, though with no difference between the three treatment arms. Kruidenier et al. [14] used a six-month training intervention, but no further follow-up beyond the end of the intervention was Int. J. Environ. Res. Public Health 2013, reported. They found an increased walking distance with additional SET after PTA after six months compared to PTA alone. However, no additional improvement in HRQoL was observed. Thus, the aims of this study were to explore the effects during one year of 12 weeks of SET (not claudicant specific) after PTA and to compare them with those of PTA alone on physical function, limb hemodynamics and HRQoL in patients with severe claudication. We hypothesised that the group offered SET after PTA would have better results in terms of a positive effect on physical function as well as HRQoL and limb hemodynamics. 2. Methods 2.1. Study Design The study was a blinded, prospective, randomised clinical trial with parallel group design. It followed the Consolidated Standards of Reporting Trials (CONSORT) statement criteria for reporting clinical trials [16] Sample and Sample Size Calculation Recruitment, interventions and data collection were performed at Oslo University Hospital Aker, Oslo, Norway, between March 2010 and June Patients eligible for participation in this study were patients selected to undergo PTA due to intermittent claudication (Fontaine stage II) after best medical treatment had failed. Best medical treatment consisted of an urgent request of smoking cessation, appropriate medication for lowering lipids and for diabetes mellitus and hypertension if present, and most important, strongly advise to start or continue exercise. A further requirement was availability to return for hospital-based exercise twice weekly for three months. The exclusion criteria were previous PTA on the same leg during the previous two years, a present unsuccessful attempt at PTA, asymptomatic PAD (Fontaine stage I), critical limb ischemia (Fontaine stage III or IV) and reduced walking ability caused by factors other than PAD (i.e., orthopaedic problems, spinal stenosis, angina pectoris or dyspnoea). The lesions were determined by clinical examination, ABI and ultrasound triplex as a part of the assessment by the vascular specialist. If indication for further investigations, the participants were referred to MRA (or CTA if MRA was contraindicated) to better estimate the options for possible endovascular treatment. Sample size calculation was performed based on the primary outcome Six-Minute Walk Test (6MWT). According to Perera et al. [17] the number needed per group with 80% power for a between-group comparison of a substantial meaningful change in the 6MWT (50 m, standard deviation 50 m) is 13 20, and of a small clinically meaningful change for the 6MWT (20 m, standard deviation 50 m) is These numbers are not based specifically on patients with intermittent claudication, however the symptoms of the latter are quite comparable to mild to moderate mobility deficits. We have calculated that with significant level of 5% and keeping statistical power of 80%, we would need 22 patients in each group so that a difference of 30 m or larger would be statistically significantly different from 50 m (a known threshold). Int. J. Environ. Res. Public Health 2013, Ethical Considerations Approval was obtained from the regional research ethics committee, and written informed consent was obtained from each participant. The study was performed according to the Helsinki Declaration and is registered at ClinicalTrials.gov (NCT ) Randomisation and Blinding The participants were stratified according to the treatment site (aortoiliac or femoropopliteal) and randomised into the intervention or control group (ratio 3:2) after the PTA. The ratio 3:2 was chosen with regards to the intervention group s more demanding effort and therefore possibly a greater drop-out rate in this group. A computer-generated block-randomised list was used together with consecutively numbered and sealed envelopes. The administrative staff prepared the sealed envelopes in advance, and the block size and randomisation list were inaccessible to the project coordinator (E.B.), who enrolled the patients and assigned them to the groups. The assessors were blinded to the group assignment PTA and Post-Operative Care PTA was performed by a vascular interventional radiologist in accordance with the hospital s guidelines. Access was gained through puncture of the common femoral artery; retrograde for treatment of lesions in the aortoiliac segment and antegrade for treatment of lesions in the femoropopliteal segment. A six French sheath was introduced. Lesions in iliac arteries were all treated with stents primarily. In femoropopliteal lesions we preformed balloon angioplasty, and implanted stent only in case of flow-limiting dissection or significant residual stenosis. Both groups received post-operative care in agreement with the ward s usual procedures and were discharged either the same day or on the first post-operative day. The discharging doctor and the responsible nurse gave general advice on the importance of exercise, smoking cessation and diet Intervention The intervention group received hospital-based SET two days per week for 12 weeks. In addition, the participants conducted one home-based exercise session every week. After the period of hospital-based SET, the participants conducted three home-based exercise sessions every week for an additional 12 weeks. The SET was based on The Norwegian Ulleval Model [18], a modified cardiac rehabilitation program, and was slightly adjusted to be applicable to this patient group. Each SET session lasted for 60 min and consisted of warm-up exercises, three high-intensity intervals (each lasting for five to ten minutes), two moderate-intensity intervals (each lasting for five to ten minutes) and cool-down exercises, including stretching. The exercises were simple aerobic dance movements and walking, and involved the use of both upper and lower extremities. During walking the participants walked alternating in a circle in the gym, in the corridor or stair climbing. The instructor walked the opposite direction within the circle or close by in the corridor and the stairs to monitor the participants. The exercise intensity was adjusted using the Borg scale of perceived exertion [19] and the beats per minute of the music [18]. During the high-intensity exercises, the participants were motivated to Int. J. Environ. Res. Public Health 2013, gradually increase their exercise intensity towards on the Borg scale, and during the exercise sessions, the patients informed the instructor of their Borg Scale ratings. The participants also used this scale to monitor the home-based exercise session each week. No extra equipment was required for this program. Each session had between two and twelve participants. The control group did not receive any additional follow-up regarding exercise beyond general advice on the importance of exercise at discharge Assessments at Baseline and Follow-ups All measurements were taken during a single visit at baseline (prior to the planned PTA) and three, six and 12 months after the PTA. The primary outcome was a standardised Six-Minute Walk Test (6MWT). The 6MWT was performed in a 30 m pre-marked hospital corridor, and instructions and encouragements were given in accordance with the test s guidelines [20]. This test is well validated in PAD patients and has shown good reliability in this patient group [21,22]. Secondary outcomes were measurement of physical function, limb hemodynamics and HRQoL. The physical function measurements were pain-free walking distance (PFWD) and maximal walking distance (MWD) on a treadmill (graded protocol, 3.2 km/h constant speed, starting with a 0% incline that increased 2% every two minutes up to 10%) [23]. Treadmill testing is a well-accepted means of testing walking distance for this patient group [4,24] and has shown very high reliability [25]. Limb hemodynamics were measured using the ankle-brachial-index (ABI) (ankle-pressure/arm-pressure) by doppler and pulse volume recording (PVR) on the leg by a pressurized cuff on the leg connected to a plethysmograph (Stranden macrolab, Oslo, Norway). In addition, all participants were measured by triplex ultrasound at baseline and all follow-ups. HRQoL was measured with a generic instrument, the Short Form 36 (SF-36) [26], as well as a disease-specific instrument, the Claudication Scale (CLAU-S) [27]. The SF-36 has previously been used in numerous PAD studies and is recommended as one of the most appropriate generic instruments for this patient group with regard to validity, reliability and responsiveness [28,29]. The eight domains on the SF-36 are physical function, physical role, bodily pain, general health, vitality, social function, emotional role and mental health. The SF-36 raw scores were coded and recalibrated following standard guidelines [26], and the items were then summed and transformed into the eight scales ranging from 0 to 100 (higher scores indicate better quality of life). CLAU-S is a valid instrument [30] and has five subscales: daily life, pain, social life, disease-specific anxiety and psychological well-being. The CLAU-S raw scores were also coded, recalibrated, summed and transformed into the five scales ranging from (higher scores indicate better quality of life) Statistical Analysis Continuous data in the tables are described with mean and standard deviation or standard error of the mean (SEM) when normally distributed or with median and range when having a skewed distribution. Categorical variables are presented as numbers and percentages. Crude differences between pairs of categorical variables were assessed with Chi-square tests and with Mann-Whitney Wilcoxen test for continuous variables. Changes over time and differences between groups were analysed using mixed models for repeated measures with group, time and the interaction between time and group being modelled as fixed effects. The dependencies between time points were modelled using Int. J. Environ. Res. Public Health 2013, diagonal covariance matrix. p-values 0.05 were considered statistically significant and all tests were two-sided. All analyses were conducted using SPSS 20.0 (SPSS Corporation, Chicago, IL, USA). 3. Results Of the 118 patients potentially eligible for the study, 50 participants were included. Participants who did not meet the inclusion criteria were excluded. The main exclusion reasons were work-related obligations, previous PTA during the previous two years, reduced walking ability due to other factors than PAD and lack of interest to participate in the study. Figure 1 shows the flow of participants through the study. Altogether, six participants underwent re-intervention after three months follow-up. Two participants withdrew during follow-up, after three and six months, respectively. One participant died before 12 months follow-up. There were no statistically significant differences between genders at baseline regarding the variables connected to the main outcome. The general participant characteristics are shown in Table 1. Table 1. Participant characteristics at baseline. Intervention group (n = 29) Control group (n = 21) Mean (SD) Mean (SD) or or % (n) % (n) Demographics Age (years) 66.9 (7.1) 66 (8.3) Body mass index (kg/m 2 ) 27.2 (5) 27.4 (4) Gender (men) 14 (48.3) 10 (47.6) Marital status (married) 18 (62.1) 10 (47.6) Years of school ( 9 years) 22 (75.9) 16 (76.2) Blood status Total cholesterol (mmol/l) 4.8 (1) 4.9 (1.1) HDL 1 (mmol/l) 1.7 (0.6) 1.6 (0.6) LDL 1 (mmol/l) 2.6 (0.7) 2.6 (0.8) Triglycerides (mmol/l) 1.3 (0.6) 1.5 (1) HbA1c 1 (%) 5.9 (0.7) 6.2 (0.6) Smoking status Have never smoked 0 (0) 4.8 (1) Used to smoke 62.1 (18) 52.4 (11) Currently smoke 37.9 (11) 42.8 (9) Current medication Statins 96.6 (28) 90.5 (19) Platelet inhibitors 86.2 (25) 95.2 (20) Anticoagulants 6.9 (2) 0 (0) Hypertension 51.7 (15) 61.9 (13) Comorbidity Diabetes 10.3 (4) 19.0 (4) COPD 6.9 (2) 4.8 (1) Previous cardiovascular events Myocardial infarction 27.6 (8) 38.1 (8) Stroke/TIA (1) 0 (0) Peripheral arterial surgery or endovascular treatment 17.2 (5) 19.0 (4) 1 HDL = high-density lipoproteins; LDL = low-density lipoproteins; HbA1c = hemoglobin A1c; COPD = chronic obstructive pulmonary disease; TIA = transient ischemic attack. Int. J. Environ. Res. Public Health 2013, Figure 1. CONSORT flow chart of the study. Int. J. Environ. Res. Public Health 2013, Physical Function Physical function measured by walking distance (6MWT, MWD and PFWD) showed a statistically significant difference between the two groups at the 12-month follow-up (p = 0.005, p 0.001, p = 0.014, respectively). The intervention group showed a greater change in walking distance than the control group (Table S1 and Figure 2). In the 6MWT, both groups achieved a statistically significant increase in walking distance at three months follow-up. The intervention group continued to increase in walking distance up to 12 months follow-up, while the control group showed a decrease in walking distance from three to six months and then maintained this level at 12 months. For the MWD and PFWD, the progress followed the same pattern in both groups: an increase up to six months and maintaining the same level from six to 12 months. When analysed as percentage mean change from baseline to 12 months, the mean change of 6MWD was 23% and 15% in the intervention group and the control group, respectively. For the MWD the percentage mean change from baseline was 107% in the intervention group and 96% in the control group, and for the PFWD the percentage mean change from baseline was 346% in the intervention group and 293% in the control group. Figure 2. Walking
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