Atrial arrhythmias and heart failure: a "modern view" of an old paradox

BACKGROUND

Heart failure (HF) and atrial arrhythmias (AAs) are two clinical conditions that characterize the daily clinical practice of cardiologists. In this perspective review, we analyze the shared etiopathogenetic pathways of atrial arrhythmias, which are the most common cause of atrial arrhythmias-induced cardiomyopathy (AACM) and HF.

HYPOTHESIS

The aim is to explore the pathophysiology of these two conditions considering them as a "unicum", allowing the definition of a cardiovascular continuum where it is possible to predict the factors and to identify the patient phenotype most at risk to develop HF due to atrial arrhythmias.

METHODS

Potentially eligible articles, identified from the Electronic database (PubMed), and related references were used for a literature search that was conducted between January 2022 and January 2023. Search strategies were designed to identify articles that reported atrial arrhythmias in association with heart failure and vice versa. For the search we used the following keywords: atrial arrhythmias, atrial fibrillation, heart failure, arrhythmia-induced cardiomyopathy, tachycardiomyopathy. We identified 620 articles through the electronic database search. Out of the 620 total articles we removed 320 duplicates, thus selecting 300 eligible articles. About 150 titles/abstracts were excluded for the following reasons: no original available data, no mention of atrial arrhythmias and heart failure crosstalk, very low quality analysis or evidence. We excluded also non-English articles. When multiple articles were published on the same topic, the articles with the most complete set of data were considered. We preferentially included all papers that could provide the best evidence in the field. As a result, the present review article is based on a final number of 104 references.

RESULTS

While the pathophysiology of AACM and Heart Failure with reduced ejection fraction (HFrEF) has been studied in detail over the years, the causal link between atrial arrhythmias and heart failure with Preserved Ejection Fraction (HFpEF) has been often subject of interest. HFpEF is strictly related to AAs, which has always been considered significant risk factor. In this review we described the pathophysiological links between atrial fibrillation and heart failure (Fig. 1). Furthermore, we illustrated and discussed the preclinical and clinical predicting factors of AF and HFpEF, and the corresponding targets of the available therapeutic agents. Finally, we outlined the patient phenotype at risk of developing AF and HFpEF.

CONCLUSIONS

In this review, we underline how these two clinical conditions (AF and HFpEF) represent a "unicum" and, therefore, should be considered as a single disease that can manifest itself in the same phenotype of patients but at different times. Furthermore, considering that today we have few therapeutic strategies to treat these patients, it would be good to make an early diagnosis in the initial stages of the disease or intervene even before the development of signs and symptoms of HF. This is possible only by paying greater attention to patients with predisposing factors and carrying out a targeted screening with the correct diagnostic methods. A systemic approach aimed at improving the immuno-metabolic profile of these patients by lowering the body mass index, threatening the predisposing factors, lowering the mean heart rate and reducing the sympathetic nervous system activation is the key strategy to reduce the clinical impact of this disease. This article is protected by copyright. All rights reserved.

842 PREVALENCE AND MECHANISMS OF SEVERE MITRAL AND TRICUSPID RECURGITATION IN A HEART FAILURE OUTPATIENTS POPULATION

Introduction

Mitral regurgitation (MR) and tricuspid regurgitation (TR) are an established cause of morbidity and mortality in heart failure (HF) patients. The development of successful transcatheter therapies for mitral and tricuspid diseases have opened new therapeutic opportunities, in addition to guideline-directed medical therapy (GDMT) for HF. However, an accurate evaluation of the mechanisms of valve regurgitation is key to tailor the best treatment for each patient. This study aims at evaluating the prevalence and underlying mechanisms of at least moderate-to-severe (≥3+/4+) MR and/or TR in a cohort of HF outpatients.

Methods

We retrospectively analyzed the medical records of 1260 outpatients evaluated by our HF Unit between January 2020 and June 2021. All patients with echocardiographic evidence of at least moderate-to-severe MR and/or TR were included in the registry and a thorough review of echocardiographic images and collection of clinical data were also performed.

Results

Of the 1260 analyzed patients, 173 (13.7%) presented with at least moderate-to-severe MR and/or TR and were included in the registry. The mean age was 80±7 years and median ejection fraction was 45% (IQR 33; 55%) and 77 (45%) had HF of ischemic etiology. All patients were treated with maximal tolerated doses of GDMT and, when appropriate, with devices and myocardial revascularization.

At least moderate-to-severe MR and TR was observed in 7.3% (92/1260) and 9.3% (117/1260) patients, respectively. Patients with significant isolated MR were 56 (4.4%), with isolated TR were 81 (6.4%), while with both significant MR and TR were 36 (2.8%). Among patients with significant MR, 54% (50/92) had functional valvular defect, of whom 82% (41/50) had a ventricular etiology (18/41 with asymmetric tethering), while the 18%(9/50) an atrial one (3/9 with atriogenic tethering). Among patients with significant TR, 72.6% (85/117) had functional valvular defect, of whom 35.3% (30/85) had a ventricular etiology while 64.7% (55/85) presented with an atrial one.

Conclusion

Despite optimized GDMT, the prevalence of patients presenting with significant MR and TR was considerably high in our ambulatory HF population. This registry is the first study to comprehensively detail the mechanisms of atrioventricular valve regurgitations in a wide cohort of HF outpatients.

Further studies are needed to assess the reasons for a potential undertreatment and to identify the patients who would benefit the most from the percutaneous correction of their valvular defects.