Commentary on ‘Symptom network structure of anxiety, depression and their impact on quality of life in patients undergoing percutaneous coronary intervention patients: a cross-sectional study’

This invited commentary refers to ‘Symptom network structure of anxiety, depression, and their impact on quality of life in patients undergoing percutaneous coronary intervention: a cross-sectional study’, by Z. He et al., https://doi.org/10.1093/eurjcn/zvaf062. Percutaneous coronary intervention (PCI) is a non-surgical approach that enables interventional cardiologists to visualize and treat coronary arteries to improve blood flow to heart muscle. The first PCI was performed in 1977 by Andreas Gruentzig, a German radiologist and cardiologist. He was the first person to conduct a coronary angioplasty on an awake alert human patient. His innovation changed the face of interventional cardiology. Had he not died tragically, at the age of 46 years in an accident, no doubt he would have made other amazing contributions in the world of interventional cardiology. Balloon angioplasty evolved with the introduction of coronary stenting to address the challenge of restenosis. More technological breakthroughs followed with the advent of drug-eluting stents. The application of PCI for people with acute and evolving ST elevation myocardial infarction heralded the advent of primary PCI (PPCI) which modernized approaches to revascularization for this acute condition. An interventional cardiologist could now directly visualize blockages in the coronary artery and ‘fix’ them. When PPCI is made available, within a 90-minute window, in a large volume centre, with a skilled interventionalist, patient outcomes were found to be superior when compared with thrombolytic therapy.1 So, the use of PCI as an approach has grown exponentially across the world. More than two million PCI procedures are performed every year across the world.2 Whilst technology and innovation in cardiology have progressed rapidly, the level of support for people, and those close to them, recovering after PCI has not. As a nurse working in London in the 1980s, I remember caring for patients with chronic angina who were treated electively with straight balloon angioplasty for symptomatic relief. What struck me back then was that patients did not have much support for their recovery. At that time, cardiac rehabilitation was not made available to this patient group. Whilst this has changed, referral rates following PCI tend to be about 50%, far lower than equivalent figures for people revascularized with coronary artery bypass surgery, which are over 90%.3 Because people who are recovering from PCI are prone to negative mood states, support through interventions such as cardiac rehabilitation is important. Several studies have reported on the prevalence of anxiety and depression before and after PCI.4,5 For most, but not all, the symptoms of negative mood states tend to decrease over time.4,5 However, not surprisingly an inverse relationship between negative mood states, such as anxiety, and health-related quality of life have been reported after PCI.6 Accordingly, the assessment of negative mood states before and after PCI has been identified as an important element of cardiac rehabilitation.7 Whilst the measurement of negative mood states may be helpful, we understand surprisingly little about the complexity of early recovery after PCI. The study by He et al.8 provides us with novel research which could inform a new ‘lens’ for the way we understand the constellation of symptoms that comprise negative mood during recovery for people treated with PCI. In their cross-sectional study, conducted in China, a sample of 528 patients who were treated with PCI completed validated patient reported outcome measures to investigate the symptom patterns of anxiety and depression networks. A real strength of this study is the rather novel underpinning ‘network theory’ proposed by Borsboom.9 This model provides us with a fascinating alternative to the conventional, reductionist, biomedical model of psychiatric disorders as simply brain disorders; instead, this model proposes that a stable network of causally interacting symptoms together with environmental factors may provide a new explanatory strategy.10 The authors analysed the constellation of self-reported symptoms, collected using the self-report measures, to understand their interconnectedness and correlations. Not surprisingly, anxiety, and depressive symptoms were negatively correlated with quality of life. Self-reported sleep disturbance was reported as playing a significant role in the development of anxiety and depression. Moreover fatigue, trouble relaxing and excessive worry were strongly correlated with both sleep disturbance and quality of life. Finding also showed that women recovering from PCI could experience higher levels of anxiety and depression compared to male counterparts. Cardiac rehabilitation programmes have recognized anxiety and fatigue as important variables in recovery, but less emphasis appears to be given to sleep disturbance. The authors suggest that a greater focus upon understanding these specific symptoms may enable us to better refine interventions to support patients treated with PCI. Because PCI can be performed electively, urgently or as an emergency, future studies on this topic could look at these subgroups. The specific patient PCI journey may be conceptualized as an ‘environmental’ factor that could influence levels of anxiety and depression during recovery. Felicity Astin (Conceptualization: [lead]; Writing—original draft: [lead]; Writing—review & editing: [lead]) No funding received. This commentary does not contain new data.