Atrial fibrillation in heart failure patients: An update on renin-angiotensin-aldosterone system pathway blockade as a therapeutic and prevention target.

Heart failure (HF) and atrial fibrillation (AF) are two cardiovascular (CV) entities that affect millions of individuals worldwide and their prevalence is translated into a significant impact on health care systems. The common pathophysiological pathways that these two share have created an important clinical interrelation, as the coexistence of HF and AF is associated with worse prognosis and treatment challenges. Renin-angiotensin-aldosterone system (RAAS), a critical mechanism in blood pressure (BP) control, was proved to be involved in the pathogenesis of both conditions contributing to their further coexistence. Successful control of BP is of great importance to the management of HF, crucial for the prevention of arrhythmiogenic substrates, while RAAS antagonists may possibly affect the development of new-onset AF as well. There are numerous studies that evaluated the effectiveness of RAAS blockade in AF/HF population and despite comparable or modest results, there is a well-established suggestion that RAAS blockers may contribute to a reduction of HF, CV events and recurrence of AF, along with their potential effective role in the new-onset AF prophylaxis. Angiotensin receptor blockers, according to the evidence, are more effective in that direction, followed by angiotensin converting enzyme inhibitors, whereas the data on aldosterone antagonists are not encouraging, yet do have the potential of significant CV disease modificators regardless of their effects on BP.

Digoxin Impact on Heart Failure Patients with Atrial Fibrillation.

Background: Digoxin is a cardiac glycoside, derived from the plant Digitalis purpurea. For many years digitalis has been widely used in the treatment of heart failure (HF), owing to its cardiotonic and neurohormonal effects and atrial fibrillation (AF), due to its parasympathomimetic effect on the AV node. Objective: The aim of this paper is to evaluate the available evidence on the safety and efficacy of digoxin in patients with HF and AF, by reviewing the pertinent literature. Methods: We conducted a PubMed/MEDLINE and SCOPUS search to evaluate the currently available evidence on the administration of digoxin and its association with all-cause mortality risk in patients with AF and HF. Results: Several observational analyses of clinical trials and meta-analyses have shown conflicting results on the safety and efficacy of digoxin administration in patients with AF and HF. According to these results, digoxin should be avoided in patients without HF, as it is associated with worse outcomes. On the other hand, in patients with AF and HF digoxin should be used with caution. Conclusion: The impact of digoxin on all-cause mortality and adverse effects in these patients remains unclear based on the current evidence. More trials at low risk of bias evaluating the effects of digoxin are needed.