INTRODUCTION
Cardiovascular disease (CVD) presents a huge burden of disease globally.1 2 However, in the past three decades, there has been a significant decline in deaths caused by CVD in all high-income and some middle-income countries.1 Consequently, there has been an increase in the number of people living with CVD. Depression and anxiety are among the most common comorbidities in CVD and are up to three times more prevalent in people with CVD than in the general population.3 4 In the UK, 28% of cardiac patients report borderline or clinically significant levels of anxiety when starting cardiac rehabilitation (CR), and 19% report borderline or clinically significant levels of depression.5 Depression and anxiety in those with CVD are linked to poorer treatment adherence and quality of life, increased use of healthcare, risk of future cardiac events and mortality.6–8 CR is widely considered a means for psychological support using techniques such as relaxation training, stress management and cognitive–behavioural therapy (CBT).9–12 Qualitative studies have investigated types of psychological support cardiac patients would prefer, which include talking therapies and group-based interventions, rather than antidepressants.13 14 In practice, however, CR staff and patients report minimal discussion of emotional needs, with patients being reluctant to talk about their worries and dismissive of guided relaxation and stress management techniques as these are viewed as superficial.14 15 Meta-analyses of current psychological interventions for cardiac patients show high variability, low study quality and often weak outcomes.16 17 It is evident that more effective psychological interventions and higher-quality trials are needed.
Advances in mental health treatment might offer translational opportunities for treating psychological distress in CR patients. A recently developed treatment, metacognitive therapy (MCT)18 19 is highly effective in mental health settings. A meta-analysis evaluating the efficacy of MCT for anxiety and depression found that MCT produced large post-treatment effect sizes compared with waitlist control (hedges g=2.06).20 When MCT was compared with cognitive and behavioural interventions there were large effect sizes favouring MCT at post treatment (hedges’ g=0.69). MCT is based on an information processing model21 22 of psychological disorder in which distress is maintained by a maladaptive thinking style called the cognitive attentional syndrome (CAS). The CAS is characterised by difficult to control repetitive negative thinking (ie, worrying, rumination, dwelling on events), inflexible attention and maladaptive coping strategies (eg, avoidance, thought suppression) and is linked to underlying positive and negative metacognitive beliefs. Positive metacognitive beliefs concern the usefulness of worrying, for example ‘worrying means I’m prepared’, while negative metacognitive beliefs concern the harmfulness and uncontrollability of overthinking, for example ‘worrying will cause me to have a heart attack’, ‘I can’t stop worrying’. Pilot studies suggest that MCT is a feasible treatment that can be effective in physical health and in anxiety and depression in CR patients in particular.23
While quantitative research can establish the efficacy of psychological interventions the focus is limited to establishing whether there is a causal relationship between an intervention and patient change. Quantitative methods cannot provide insights into how complex interventions such as MCT are experienced or understood by patients.24 25 Qualitative methods are designed to facilitate insight into patients’ experiences and understanding of complex interventions and can provide information on how treatments are received, addressing questions concerning the appropriateness of the intervention, why it was successful or not, and any variation in effectiveness in the sample.24 Thus, qualitative methods are advocated for the understanding and transferability of complex interventions.26 27
This qualitative study was conducted as part of the National Institute for Health Research funded PATHWAY trial, which compared group MCT plus CR to CR alone for psychologically distressed CR patients.23 28 We interviewed patients in the intervention arm when they had completed group MCT. Our aims were to explore patients’ experiences and understanding of group MCT. In particular, we wanted to understand whether and how patients had engaged with and used the different techniques and what they valued in the treatment.