Two Closely Related Comorbidities: Atrial Fibrillation and Heart Failure
Heart failure and atrial fibrillation (AF) are growing cardiovascular disease epidemics worldwide. Heart failure with left-ventricular systolic dysfunction (LVSD) can be found in more than one-third of all patients with AF. Conversely, up to half of the subjects with LVSD suffer from AF. Both frequently coexisting comorbidities can cause or exacerbate each other and worsen the prognosis of the patients.[1,2] However, in many cases it remains unclear whether LVSD preceded AF or vice versa. Thus, the causal interaction between AF and the left ventricle with potential LVSD remains a—still ambiguous—chicken and egg problem (Figure 1).
Atrial fibrillation and heart failure frequently coexist. Both comorbidities can induce each other thereby causing a chicken–egg causality dilemma in these respective patients.1 LV, left ventricular.
Recent clinical evidence indicates that AF can induce LVSD, heart failure-related morbidity, and mortality. The CASTLE-AF trial demonstrated that catheter ablation of AF can improve mortality, heart failure hospitalization, and LVSD in patients with heart failure with reduced ejection fraction and AF. However, it has to be taken into account that included patients also suffered from other causes for LVSD in addition to AF. More specifically, the CAMERA-MRI trial investigated patients with AF and idiopathic cardiomyopathy (LV ejection fraction ≤ 45%), where other identifiable causes of LVSD such as significant coronary artery disease were ruled out. In this trial, rhythm control via catheter ablation improved LV function compared with medical rate control. However, previous studies on rhythm control therapy in patients with LVSD also reported contrasting results in particular when using antiarrhythmic drugs for rhythm control. While a recent meta-analysis substantiated the favourable effects of rhythm control via catheter ablation on mortality, LV function, and heart failure status in patients with AF and heart failure, further studies on rhythm control therapies are needed.
While AF begets heart failure, also heart failure can cause/precede AF and a significant proportion of patients with different types of heart failure develop AF over time. The mechanisms include an increase in left atrial pressure with consecutive atrial enlargement and adverse structural and electrical remodelling. In patients with lone AF also an occult cardiomyopathy may underlie AF induction. Thus, identification and classification of patients with AF and heart failure are of utmost importance for appropriate and personalized management and further basic and clinical research is required to shed light into this vicious partnership.
Eur Heart J. 2022;43(36):3376-3378. © 2022 Oxford University Press
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