Elsevier

Journal of Nuclear Cardiology

Volume 29, Issue 6, December 2022, Pages 2824-2836
Journal of Nuclear Cardiology

Original Article
Metabolic activity of the left and right atria are differentially altered in patients with atrial fibrillation and LV dysfunction

https://doi.org/10.1007/s12350-021-02878-2Get rights and content

Abstract

Background

Alterations in atrial metabolism may play a role in the perpetuation of atrial fibrillation (AF). This study sought to compare 18F-fluorodeoxyglucose (FDG) uptake on PET, in patients with LV dysfunction versus those without AF.

Methods

Seventy-two patients who underwent myocardial viability assessment were evaluated. AF patients (36) had persistent or permanent AF based on history and ECG. Patients without AF (36) were matched to AF patients based on sex, diabetes, age, and LVEF. Maximum and mean FDG Standard Uptake Values (SUV) in the left atrial (LA) wall and right atrial (RA) wall were measured. Tissue-to-blood ratios (TBR) were calculated as atrial wall to blood-pool activity. Atrial volumes were measured by echocardiography.

Results

Maximum and mean FDG SUV and TBRs were significantly increased in the RA (but not the LA) of patients with AF compared to those without (P < 0.01). When accounting for changes in atrial volume, the presence of AF remained a significant predictor of higher RAMAX, but not RAMEAN FDG uptake.

Conclusion

In patients with LV dysfunction from ischemic cardiomyopathy, LA and RA glucose metabolism are differentially altered in those with persistent atrial fibrillation. Further investigations should elucidate the temporal relationship between AF and glucose metabolic changes, as a potential target for therapy.

Spanish abstract

Antecedentes

Las alteraciones en el metabolismo auricular pueden desempeñar un papel en la persistencia de lafibrilación auricular (FA). Este estudio buscó comparar la captación del PET con 18F fluorodesoxiglucosa(FDG), en pacientes con disfunción del VI con y sin FA.

Métodos

Se evaluaron setenta y dos pacientes que se sometieron a evaluación de viabilidad miocárdica. Los pacientes con fibrilación auricular (36) tenían fibrilación auricular persistente o permanente según su historia clínica y el ECG. Los pacientes sin FA (36) se compararon con los pacientes con FA en base a género, diabetes, edad y FEVI. Se midieron los valores de captación estándar (SUV) máximos y medios de FDG en la pared de la aurícula izquierda (LA) y la pared de la aurícula derecha (RA), y se calcularon las relaciones de tejido al pool sanguíneo (TBR) como pared-a-pool sanguíneo. Volúmenes auriculares fueron medidos por ecocardiografía

Resultados

Los SUV y TBR de FDG máximos y medios se encontraron significativamentemayores en la RA(pero no en la LA) de los pacientes con FA en comparación con los que no la tenían (p<0.01). Al tener en cuenta los cambios en el volumen auricular, la presencia de FA siguió siendo un predictor significativo de una mayor captación de FDG en RAMAX pero no de RAMEAN

Conclusión

En pacientes con disfunción del VI por miocardiopatía isquémica, el metabolismo glucolítico en laLA y en la RA se altera de manera diferencial en quienes tienen fibrilación auricular persistente.Futuras investigaciones deberían dilucidar la relación temporal entre la FA y los cambios metabólicos de la glucosa, como un objetivo potencial para la terapia.

Chinese abstract

背景

心房代谢的改变可能在心房颤动 (AF) 的持续中起作用。本研究旨在比较有无合并房颤左心室 (LV) 功能障碍患者中, 18F-氟脱氧葡萄糖 (FDG) 在PET 中的摄取量有无差异。

研究方法

本研究纳入了72 名接受心肌活力评估的患者。根据病史和心电图, 房颤患者 (36 人) 诊断为持续性或永久性房颤。根据性别、糖尿病、年龄和LVEF, 对应匹配无房颤患者36 人。本研究测量了左心房 (LA) 壁和右心房 (RA) 壁的最大和平均FDG 标准摄取值 (SUV), 并计算了组织-血液比率 (TBR), 即心脏壁-血液池。心房容积由超声心动图测量。

结果

与无房颤患者相比, 房颤患者的RA (但不包括LA) 的最大和平均FDG 标准摄取值 (SUV) 和组织-血液比率 (TBRs) 都明显增加 (P<0.01)。当考虑到心房容积的变化时, 患者是否合并房颤仍然是右房最大标准化摄取值 (RAMAX) 升高的重要预测因素, 但不是右房平均标准化摄取值 (RAMEAN) FDG摄取的重要预测因素。

结论

在缺血性心肌病导致的左心室功能障碍的患者中, LA 和RA 的葡萄糖代谢在持续房颤的患者中会有显著的改变。后续研究应进一步阐明房颤和葡萄糖代谢变化之间的时间关系, 并作为治疗的潜在靶点。

French abstract

Mise en contexte

Les changements du métabolisme auriculaire peuvent jouer un rôle dans la perpétuation de la fibrillation auriculaire (FA). La présente étude avait pour but de comparer la captation du 18F-fluorodeoxyglucose (FDG) en TEP (tomographie par émission de positrons) chez les patients avec une dysfonction du VG avec FA versus sans FA.

Méthodologie

Soixante-douze patients chez qui une étude de viabilité myocardique a été effectuée ont été évalués. Les patients avec FA (36) avaient une FA persistante ou permanente basée sur l’histoire clinique et l’ECG. Les patients sans FA (36) ont été assortis aux patients avec FA selon leur sexe, diabete, leur age et FEVG. Les ICN (indice de captation normalisée) du FDG maximal et moyen au niveau des parois de l’oreillette gauche (OG) et de l’oreillette droite (OD) ont été mesurées et les rapport tissus-sang (RTS) ont été calculés comme parois-pool sanguin. Les volumes auriculaires ont été mesurés par échocardiographie.

Résultats

Les ICN maximaux et moyens du FDG et les RTS étaient significativement augmentés dans OD (mais pas dans OG) chez les patients avec FA comparativement à ceux qui n’ont pas de FA (p < 0.01). Lorsque les changements du volume auriculaire sont pris en considération, la présence avec FA demeure un facteur prédicteur significatif d’une captation du FDG OD maximale plus élevée mais pas pour la captation OD moyenne.

Conclusion

Chez les patients avec dysfonction du VG reliée à une cardiomyopathie ischémique, le métabolisme du glucose dans OG et OD est altéré différemment chez les patients avec une FA persistante. D’autres études devront être effectuées afin d’élucider la relation temporelle entre la FA et les changements du métabolisme du glucose comme cible potentielle pour la thérapie.

Introduction

Atrial fibrillation (AF) is the most frequently encountered cardiac arrhythmia.1,2 It is associated with increased morbidity and mortality and is an independent risk factor for stroke.3 It has been shown that “atrial fibrillation begets atrial fibrillation”4 through a poorly understood process often referred to as “atrial remodeling”.5

A change in atrial metabolism during the arrhythmic state may play a role in promoting the AF substrate, due to increased atrial metabolic demand.6,7 Findings in animal models and human studies have suggested a link between altered metabolic activity, including altered glucose metabolism and this common arrhythmia.8, 9, 10, 11, 12, 13

A deeper comprehension of the pathophysiology and metabolic changes associated with AF may lead to potential targets for therapy. Although treatments to restore sinus rhythm such as cardioversion and catheter ablation have demonstrated success, they still have diminished effectiveness along with increased recurrence rates the longer a patient has been in AF.14,15

[18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging provides the ability to further investigate metabolic changes that may accompany atrial remodeling.16,17

There are limited imaging studies, mainly in cancer patient populations, evaluating atrial metabolic activity,18, 19, 20, 21 but none to our knowledge, using cardiac PET imaging to compare AF patients to a control population.

The aim of the present investigation was to quantitatively compare patterns of glucose uptake measured using FDG PET-CT imaging, in patients with versus without atrial fibrillation. We assessed a cohort of patients who also had LV dysfunction undergoing viability imaging. We hypothesized that patients in this cohort with persistent AF may have increased atrial FDG uptake compared to those without AF.

Section snippets

Patient Population

The study was a single center, retrospective analysis among patients from a registry database, with evidence of left-ventricular (LV) dysfunction (LVEF < 45%), history of coronary artery disease, and having undergone myocardial viability FDG PET-CT imaging between January 2010 and April 2015.The study was approved by the human research ethics board of the University of Ottawa Heart Institute.

Fifty-three consecutive FDG PET viability imaging patients were identified with some history of AF.

Baseline Demographics

The baseline characteristics of the study population (n = 72) are shown in Table 1. As per the pre-defined match criteria, both the AF group and noAF groups had equal composition of diabetes and female patients, with comparable age and LVEF. Not surprisingly, the AF group had a significantly higher proportion of patients with history of stroke or TIA than the noAF group. As expected, there was also a higher proportion of oral anticoagulation (OAC) with both Coumadin and DOAC in the AF group.

Discussion

In this study of patients with LV dysfunction, we demonstrated a significant increase in FDG uptake in the right atrial free wall among those with AF compared to those without AF. However, we did not find a difference in the left atrial free wall FDG uptake between these two groups. We also demonstrated a significant correlation between FDG uptake and right atrial volume. There was no such relationship between FDG uptake and left atrial volume. We demonstrated that when accounting for atrial

New Knowledge Gained

In patients with LV dysfunction from ischemic cardiomyopathy, there is a significant increase in FDG uptake in the right atrial free wall among those with persistent or permanent AF compared to those without AF. However, no difference in the left atrial free wall FDG uptake was found between these two groups. There is a significant correlation between RA FDG uptake and RA volume. There was no such relationship between FDG uptake and LA volume. When accounting for atrial volume, the presence of

Conclusion

Increased glucose uptake was observed in the right atrial free wall of patients with LV dysfunction from ischemic cardiomyopathy and with AF compared to those without AF. The presence of AF was a statistically significant predictor of higher RA FDG uptake, even after accounting for increased atrial volume. Further study is warranted to determine the temporal nature of these findings during AF. This may help to determine the full clinical significance of this observation and presents an

Acknowledgments

BWJC is the UOHI Goldfarb Chair in Cardiac Imaging. RSB is a Tier 1 Research Chair supported by the University of Ottawa and was a career investigator supported by the Heart and Stroke Foundation of Ontario.

Disclosures

BWJC receives research support from CV Diagnostix and educational support from TeraRecon Inc and has equity interest in GE. RdK has received research grant support and honoraria from Lantheus Medical Imaging, Jubilant DraxImage, and GE Healthcare. RdK receives royalty revenues from

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  • Cited by (0)

    JNC thanks Erick Alexanderson, MD, and Isabel Carvajal-Juárez, MD, Instituto Nacional de Cardiología Ignacio Chávez, Mexico, for providing the Spanish abstract; Weihua Zhou, Ph.D., Michigan Technological University, Michigan, for providing the Chinese abstract; and Raymond Taillefer, MD, Hopital du Haut-Richelieu, Canada, for providing the French abstract.

    The authors of this article have provided a PowerPoint file, available for download at SpringerLink, which summarizes the contents of the paper and is free for re-use at meetings and presentations. Search for the article DOI on SpringerLink.com.

    The authors have also provided an audio summary of the article, which is available to download as ESM, or to listen to via the JNC/ASNC Podcast.

    Robert A. deKemp and Rob S. B. Beanlands are co-senior authors.

    Copyright comment corrected publication 2022

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