Treatment of atrial fibrillation: is it as easy as A-B-C?

This editorial refers to ‘Relation of outcomes to ABC (Atrial Fibrillation Better Care) pathway adherent care in European patients with atrial fibrillation: an analysis fromthe ESC-EHRA EORPAtrial Fibrillation General Long-Term (AFGen LT) Registry’, by M. Proietti et al., on pages 174–183. Atrial fibrillation (AF) increases the risk of stroke, heart failure, cognitive impairment, disability, and premature death. Approximately, 7 out of 10 individuals with AF will die from cardiovascular causes,1 yet fewer than 50% of patients with AF receive guideline-directed therapy for all of their cardiovascular conditions.2 Thus, there is an increasing emphasis not only on the treatment of AF itself but also on the integrated treatment of cardiovascular risk factors and comorbid conditions that fuel the substrate that facilitates AF and its downstream consequences. The recently published 2020 European Society of Cardiology guidelines for the management of AF endorse and highlight the AF Better Care (ABC) pathway, which is intended to simplify and facilitate the delivery of comprehensive and integrated care in patients with AF.3 Once the diagnosis of AF is confirmed, clinicians should ensure anticoagulation to avoid stroke (A), better control of symptoms (B), and treatment of comorbidities (C). In a post hoc analysis of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, adherence to the ABC pathway was associated with a lower risk of adverse outcomes in complex patients, including those with multiple comorbidities.4 Adherence to the ABC pathway has also been associated with lower healthcare-related costs.5 Finally, in a cluster-randomized trial comparing usual care to integrated care with a mobile AF application that incorporated the ABC pathway, use of the mobile app ABC approach led to a 60% reduction in the composite outcome of stroke or thromboembolism, rehospitalization, and all-cause mortality.6 In this issue of Europace, Proietti et al.7 conducted a retrospective analysis of the EURObservational Research Program in AF General Long-Term Registry in order to determine if ABC care was associated with a reduced risk of adverse outcomes in general clinical practice. The authors defined successful stroke prevention as vitamin K antagonism with a time in therapeutic range ≥70% or treatment with a direct-acting oral anticoagulant in patients with a guideline recommendation.3 Better symptom control was defined as no symptoms or the presence of mild symptoms that did not affect daily life (European Heart Rhythm Association Class I or II). Finally, treatment of comorbidities required adequate blood pressure control in those with hypertension (<140/90 mmHg); use of statins in those with vascular disease, prior stroke, or transient ischaemic attack; insulin or oral hypoglycaemic agents in those with diabetes; and beta-blocker and ACE-I/ARB therapy in those with coronary artery disease or heart failure. Patients had to have all criteria met in order to be considered adherent for comorbidity treatment. Applying these criteria among 6646 patients enrolled from 250 cardiology practices across 27 countries in EURObservational Research Programme (EORP), only 30% achieved ABC adherent care. Those patients with ABC adherent care were significantly healthier, with less coronary artery disease, heart failure, diabetes, chronic kidney disease, and lower CHA2DS2-VASc and HAS-BLED scores. Acknowledging these differences, the adjusted hazard of thromboembolism, acute coronary syndrome, or cardiovascular death was lower in those with ABC adherent care compared with non-adherence. The adjusted hazards of cardiovascular death and all-cause mortality were also lower in those with ABC adherent care. The results from the EORP registry are important and suggest that adherence to ABC care is associated with improved cardiovascular outcomes; however, as the authors acknowledge there are limitations that need to be considered. First, the EORP data only permitted analysis of about 60% of the cohort. Moreover, the authors could not assess several important factors of comorbidity treatment including the degree of glycaemic control, treatment of sleep apnoea, and weight loss. Finally, the patients who received ABC adherent care were significantly different from those who did not receive adherent care, and it is very likely that unmeasured confounding influenced the association with outcomes. Whether implementation of the ABC pathway can improve outcomes in clinical practice will need to be confirmed in additional prospective studies like mAFA-II.6 Consistent with the aggregate evidence and guideline recommendations, we know that stroke prevention, symptom control, and treatment of cardiovascular risk factors and comorbidities is crucial for the successful treatment of AF. Yet, the data from EORP and other studies demonstrate that achieving ABC care is challenging. ABC adherence was 7% in the AFFIRM trial, 22% in ATHERO-AF, and 30% in the EORP registry.4,5,7 While some of these studies were conducted before ABC care was emphasized, these adherence numbers still seem low for something so important. Therefore, a key question is how do we operationalize and implement this approach to AF care in a pragmatic way? In the inpatient arena, programs focused on discharge metrics have been able to demonstrate high-rates of stroke prevention therapy; however, the outpatient arena is likely to be more challenging.8 Should ABC care be enacted with multidisciplinary or nurse-led integrated AF clinics?9,10 Should it be enacted with electronic medical record prompts and dashboards where one can easily see ABC adherence status? Moreover, how can we ensure the approach is patient-centred—or perhaps even patient-facilitated through mobile technology?6 Finally, another key question is whether or not the same approach will work in different healthcare systems across Europe and the world. It is likely that a one-size fits all approach will not work well given the unique characteristics of different national healthcare systems and care delivery models, especially when considering performance measures and pay-for-performance programs. While the ABC pathway clarifies AF care in three actionable steps, the simplicity of the approach belies the significant complexity in each of these treatment domains. For example, what is ‘better symptom control?’ What degree of symptom control should we target? Early rhythm control will be more important moving forward, even in those with minimal symptoms, given the results of the EAST trial in which implementation of rhythm control within 12 months of diagnosed AF led to a 20% relative reduction in the occurrence of death from cardiovascular causes, stroke, or hospitalization.11 Similarly, best-practice for optimal control of comorbidities is also complex, challenging, and has many unanswered questions. What is the optimal oral hypoglycaemic regiment in patients with AF? What apnoea-hypopnoea index merits treatment in those with AF? These challenges may be optimally met in comprehensive, integrated AF centres. The results from the EORP investigators highlight the potential opportunity to improve outcomes with ABC-guided care in patients with AF. Yet, we are still early in the evidence-development for ABC care. The next steps will be better understanding how we can improve ABC adherence, facilitate dissemination, and implementation across diverse healthcare delivery systems, and to better understand what the ideal treatment components of each ABC domain should be. The promise of ABC care looms large, but we still have some work to do before AF care can truly be as easy as A-B-C. Conflict of interest: J.P.P. is supported by R01HL128595 from the National Heart, Lung and Blood Institute. He receives grants for clinical research from Abbott, American Heart Association, Association for the Advancement of Medical Instrumentation, Bayer, Boston Scientific, and Philips and serves as a consultant to Abbott, Allergan, ARCA Biopharma, Biotronik, Boston Scientific, LivaNova, Medtronic, Milestone, Myokardia, Sanofi, Philips, and Up-to-Date. S.D.P. receives grants for clinical research from Boston Scientific, Bristol-Myers Squibb, Pfizer, Janssen Pharmaceuticals, Gilead; receives advisory board/speakers honoraria from Boston Scientific, Medtronic, Bristol-Myers Squibb, Pfizer, Janssen Pharmaceuticals, and Zoll. The opinions expressed in this article are not necessarily those of the Editors of Europace or of the European Society of Cardiology.