ORIGINAL ARTICLE Cardiorespiratory fitness changes in patients receiving comprehensive outpatient cardiac rehabilitation in the UK: a multicentre study Gavin R H Sandercock, 1 Fernando Cardoso, 1 Meshal Almodhy, 1 Garyfallia Pepera 2 1 Centre for Sports and Exercise Science, School of Biological Sciences, University of Essex, Colchester, Essex, UK 2 Department of Physiotherapy, TEI of Lamia, Greece Correspondence to Dr Gavin R H Sandercock, Centre for Sports and Exercise Science, School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK; gavins@essex.ac.uk Accepted 30 October 2012 ABSTRACT Background Exercise training is a key component of cardiac rehabilitation but there is a discrepancy between the high volume of exercise prescribed in trials comprising the evidence base and the lower volume prescribed to UK patients. Objective To quantify prescribed exercise volume and changes in cardiorespiratory fitness in UK cardiac rehabilitation patients. Methods We accessed n=950 patients who completed cardiac rehabilitation at four UK centres and extracted clinical data and details of cardiorespiratory fitness testing pre- and post-rehabilitation. We calculated mean and effect size (d) for change in fitness at each centre and converted values to metabolic equivalent (METs). We calculated a fixed-effects estimate of change in fitness expressed as METs and d. Results Patients completed 6 to 16 (median 8) supervised exercise sessions. Effect sizes for changes in fitness were d=0.34–0.99 in test-specific raw units and d=0.34–0.96 expressed as METs. The pooled fixed effect estimate for change in fitness was 0.52 METs (95% CI 0.51 to 0.53); or an effect size of d=0.59 (95% CI 0.58 to 0.60). Conclusion Gains in fitness varied by centre and fitness assessment protocol but the overall increase in fitness (0.52 METs) was only a third the mean estimate reported in a recent systematic review (1.55 METs). The starkest difference in clinical practice in the UK centres we sampled and the trials which comprise the evidence- base for cardiac rehabilitation was the small volume of exercise completed by UK patients. The exercise training volume prescribed was also only a third that reported in most international studies. If representative of UK services, these low training volumes and small increases in cardiorespiratory fitness may partially explain the reported inefficacy of UK cardiac rehabilitation to reduce patient mortality and morbidity. INTRODUCTION Current UK national service guidelines for cardiac rehabilitation 1 2 cite evidence from systematic reviews 3–5 of randomised controlled trials showing a ∼20% reduction in mortality for patients who com- plete exercise-based cardiac rehabilitation. The trials from which this figure was synthesised were largely completed 20–30 years ago and represent a historical vision of modern cardiac rehabilitation, 6 a version particularly unrepresentative of current pharmaco- logical practice. 6 A more recent meta-analysis 7 provided a more conservative estimate of the effect- iveness of cardiac rehabilitation to reduce mortality and rejected its efficacy in reducing secondary cardiac events. The exact studies included within each of the numerous systematic reviews published vary due to inclusion/exclusion criteria, but common to all these reviews is the paucity of UK data. The UK’s contribution to the evidence-base is two studies, both completed >20 years ago. 8 9 Neither significantly reduced the risk of either total mortality or cardiac mortality in patients receiving cardiac rehabilitation compared with the usual prac- tice group. The recent publication of data from the RAMIT group 6 has posed some serious doubts as to the efficacy of the UK cardiac rehabilitation pro- gramme’s ability to reduce patient mortality 10 and morbidity or increase quality of life. It has been suggested that data from RAMIT are already out- dated and do not fully represent current practice guidelines. 11 Nevertheless, RAMIT still represents the most detailed randomised controlled trial of comprehensive cardiac rehabilitation in the UK. The authors suggest that the decline in the appar- ent effectiveness of cardiac rehabilitation is due to improved medical management (that received by intervention as well as usual practice). Historical data suggest exercise training is an effective and fundamental element of cardiac rehabilitation (CR), 45 and more recent large-scale trials of psychological interventions alone report poor efficacy of such approaches when used in iso- lation. 12 13 A primary outcome of any exercise pro- gramme is the measurement of individuals’ response to training such as changes in strength, or, as more typically reported in cardiac rehabilita- tion trials, cardiovascular fitness. A 1% increase in VO 2peak is associated with a 2% reduction in mortality 14 ; each 1 metabolic equiva- lent (MET) increase in fitness may infer a 12% decrease in mortality. 15 Increases in fitness are independently associated with reduced mortality and morbidity and improved quality of life. 16 Individuals who have good levels of fitness are sig- nificantly less likely to suffer cardiovascular disease. 17–19 Our recent systematic review sug- gested cardiac rehabilitation may produce a 1.55 (95% CI 1.22 to 1.89) MET increase in fitness. 20 There is a relative paucity of data on changes in cardiorespiratory fitness in UK cardiac rehabilita- tion patients; we were not able to include any in our meta-analysis. Heart 2012;0:1–6. doi:10.1136/heartjnl-2012-303055 1 Secondary prevention of coronary disease Heart Online First, published on November 24, 2012 as 10.1136/heartjnl-2012-303055 Copyright Article author (or their employer) 2012. 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