What is the role of metabolic syndrome and obesity for postoperative atrial fibrillation after coronary bypass grafting?

Clinical practices for defining, detecting, and diagnosing postoperative atrial fibrillation after coronary revascularization surgery - A scoping review

OBJECTIVES

This scoping review was undertaken to understand the degree of variation in clinical practices associated with postoperative atrial fibrillation (POAF), following coronary revascularization surgery by collating and synthesising key concepts from current published literature.

REVIEW METHODS AND DATA SOURCES

This scoping review was conducted following the framework outlined by Askey and O'Malley. Reporting of this scoping review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews checklist. Initial searches were completed in September 2020 and updated in January 2023. Comprehensive searches to identify relevant published literature were carried out within CINAHL, MEDLINE, and ProQuest databases. All searches were limited to full-text papers published in English with human adult participants. Deductive content analysis using NVivo software was performed to synthesise the data.

RESULTS

A total of 692 studies were identified during the database searches. After the deletion of duplicates and the application of the inclusion and exclusion criteria, 73 studies were included in the scoping review. The included studies were published between 2001 and 2022 and included a total of 24,833 participants. Forty-six studies included a definition of POAF, with four of these citing a peak-body definition. A total of 24 included studies reported on electrocardiogram diagnostic criteria for POAF, with 13/24 [54%] describing these characteristics within their definition. The time-based diagnostic criteria ranged from a minimum duration of greater than 30 seconds to greater than 1 hour. The most frequently reported minimum-time thresholds were ≥30 seconds, reported in 12 of 51 (24%) studies and ≥5 min, reported in 13 of 51 (25%) studies.

CONCLUSIONS

There is a lack of consistency in clinical practice for defining, detecting, and diagnosing POAF, following coronary revascularization surgery. Consensus and standardisation of clinical practices are urgently needed.

Sex-Specific Cardiometabolic Determinants of Postoperative Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Cardiometabolic diseases increase the risk of postoperative atrial fibrillation (POAF), a complication leading to higher long-term risk of major cardiovascular events (MACE). It remains unknown whether the effect of these risk factors differs according to sex. We sought to evaluate the sex-specific predictors of POAF after coronary artery bypass grafting (CABG).

METHODS

In a prospective registry of patients undergoing isolated CABG, we compared predictors of POAF between sexes with logistic regression models. Because of high prevalence of abdominal obesity in women, > 80% having a waist circumference (WC) ≥ 88 cm, median WC values were used to define abdominal obesity (men ≥ 102 cm, women ≥ 100 cm).

RESULTS

This analysis included 6177 individuals (17% women). Mean age was 65.6 ± 8.9 years. POAF occurred in 32% of men and 28% of women (P < 0.05). Compared with men, women with POAF had similar WC; higher prevalence of hypertension and diabetes; lower high-density lipoprotein (HDL)-cholesterol; and higher glucose, triglyceride, low- density lipoprotein (LDL)-cholesterol, and C-reactive protein levels (all P < 0.05). After adjustment, age and abdominal obesity were associated with POAF in both sexes (P < 0.05). The interaction of WC with sex suggested a worse impact of WC on POAF risk among women (adjusted odds ratio [OR], 1.97; 95% confidence interval [CI], 1.48-2.62 vs in men 1.33; 95% CI, 1.17-1.50; P for interaction = 0.01).

CONCLUSIONS

Abdominal obesity is a major predictor of POAF in both sexes, with higher risk in women. These results emphasize the need for enhanced strategies to manage abdominal obesity and its cardiometabolic consequences in the general population and the potential to develop sex-specific preventive interventions to reduce risk of POAF.

Shensong Yangxin attenuates metabolic syndrome-induced atrial fibrillation via inhibition of ferroportin-mediated intracellular iron overload

BACKGROUND

Shensong Yangxin (SSYX) is a traditional Chinese medicine been widely used clinically to treat various arrhythmias including atrial fibrillation (AF). However, the role and precise mechanism of SSYX in MS-induced AF have not yet been elucidated.

PURPOSE

To elucidate the protective effects of SSYX on MS-induced AF and its possible mechanisms of action.

METHODS

Male Wistar rats (180-220 g) were fed a 16-week high-carbohydrate, high-fat (HCHF) diet together with 25% fructose in drinking water to produce a MS model. Low-concentration (SSYX-L, 0.4 g/kg) and high-concentration (SSYX-H, 0.8 g/kg) of SSYX were given by daily gavage 8-weeks following HCHF diet for 8-weeks. In vivo electrophysiological study, histological analysis, RNA-sequence (RNA-Seq) and gene ontology (GO) analysis, qRT-PCR and western blot were performed.

RESULTS

Both low-concentration and high-concentration of SSYX could inhibit MS-induced AF susceptibility, electrical remodeling and structural remodeling. Results from RNA-sequence analysis revealed intracellular iron homeostasis mediated the protective effect of SSYX against MS. In vivo and in vitro experiments both demonstrated that SSYX up-regulated ferroportin (Fpn) expression and ameliorated intracellular iron overload induced by MS. To verified whether Fpn is the target of SSYX and intracellular iron overload mediated the protective effect of SSYX against MS, adeno-associated virus type 9 (AAV9) delivery system was used. Knocking down Fpn (AAV9-shFpn) markedly aggravated the reactive oxygen species (ROS) production, electrical remodeling and atrial fibrosis induced by MS, leading to a further increase of AF susceptibility induced by MS.

CONCLUSION

Our study demonstrated for the first time that SSYX reduced AF susceptibility, inhibited electrical remodeling and structural remodeling via up-regulating Fpn, decreasing intracellular iron overload and reducing ROS production. These results suggest that SSYX might be a potential therapeutic agent for the treatment of MS-induced AF.

Incidence and Outcomes of Postoperative Atrial Fibrillation after Coronary Artery Bypass Grafting of a Randomized Controlled Trial: A Blinded End-of-cycle Analysis

Objective

The objective of this study is to analyse the incidence of postoperative atrial fibrillation (POAF), demography, post-operative outcomes including morbidity and mortality, length of Cardiac Intensive Care Unit (CICU) stay, High Dependency Unit (HDU) stay, and total hospital stay in patients undergoing coronary bypass grafting (CABG) at Institut Jantung Negana (IJN).

Methods

We conducted a prospective, randomised, controlled trial. We supplied the treatment group with Tocovid capsules and the control group with placebo containing palm superolein.

Results

Since January 2019, we have recruited the target population of 250 patients. However, the result is still blinded as we are still analysing blood samples for tocotrienol levels. 89.2% of patients completed the study with a 3.6% mortality and a 7.6% attrition rate. 35.2% of the patients developed POAF, the mean time being 46.06 ± 26.96 hours post-CABG. We did not observe any statistically significant difference when we compared left atrial size, New York Heart Association (NYHA) functional class, ejection fraction and premorbid history, besides EuroSCORE II (The European System for Cardiac Operative Risk Evaluation II) status except for older age group, right atrial size, and pleural effusion. There was also no difference in bypass time, cross clamp time or number of anastomoses. However, we noted a significant difference in death (p = 0.01) and renal failure requiring dialysis (p = 0.007) among patients with POAF; those patients also had a longer CICU stay (p = 0.005), HDU stay (p = 0.02), and total hospital stay (p = 0.001).

Conclusions

POAF is associated with a higher incidence of renal failure and death while it increases CICU, HDU, and total hospital stay. It remains to be seen whether Tocovid reduces POAF and its associated sequelae.

Clinical Trial Registration

NCT03807037 (Registered on 16 January 2019).

Mediterranean Diet: A Tool to Break the Relationship of Atrial Fibrillation with the Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease

Atrial fibrillation (AF) is the most common supraventricular arrhythmia associated with increased cardiovascular and non-cardiovascular morbidity and mortality. As multiple factors may predispose the onset of AF, the prevention of the occurrence, recurrence and complications of this arrhythmia is still challenging. In particular, a high prevalence of cardio-metabolic comorbidities such as the metabolic syndrome (MetS) and in its hepatic manifestation, the non-alcoholic fatty liver disease (NAFLD), have been described in the AF population. A common pathogenetic mechanism linking AF, MetS and NAFLD is represented by oxidative stress. For this reason, in the past decades, numerous studies have investigated the effect of different foods/nutrients with antioxidant properties for the prevention of, and their therapeutic role is still unclear. In this narrative comprehensive review, we will summarize current evidence on (1) the association between AF, MetS and NAFLD (2) the antioxidant role of Mediterranean Diet and its components for the prevention of AF and (3) the effects of Mediterranean Diet on MetS components and NAFLD.

Clinical factors associated with arrhythmia and short-term prognosis following mitral valve repair: a retrospective cohort study

BACKGROUND

Postoperative arrhythmia (POA) is one of the common and serious postoperative complications. This retrospective study was conducted to investigate the clinical factors associated with POA and its short-term prognosis following mitral valve repair.

METHODS

A total of 618 patients receiving mitral valve repair between January 2015 and November 2020 in our hospital were included in this retrospective study, including 318 males and 300 females and aged 53.9±9.3 years. The patients were grouped into arrhythmia and non-arrhythmia groups and investigated for risk factors associated with the prognosis of POA using multivariate logistic regression based on their clinical data.

RESULTS

POA was observed in 314 (50.8%) patients and atrial fibrillation (AF) was the most frequent (43.3%) type of POA. Compared with non-arrhythmia patients, arrhythmia patients had significantly longer time to use vasoactive drug use, longer intensive care unit (ICU) stay and longer hospital stay. In addition, the incidence of postoperative heart failure was significantly higher (P<0.05). Logistic regression analysis showed that preoperative arrhythmia [odds ratio (OR) =9.17; 95% confident interval (CI): 4.49-18.10], postoperative pain (OR =4.70; 95% CI: 1.55-6.12) and postoperative hypoxemia (OR =3.25; 95% CI: 1.04-6.28) were independently associated with POA.

CONCLUSIONS

This study demonstrates that the incidence of arrhythmia is relatively high after mitral valve repair and is associated with preoperative arrhythmia, postoperative pain and postoperative hypoxemia.

The Key Role of Uric Acid in Oxidative Stress, Inflammation, Fibrosis, Apoptosis, and Immunity in the Pathogenesis of Atrial Fibrillation

Atrial fibrillation (AF) is a highly prevalent cardiac arrhythmia that leads to numerous adverse outcomes including stroke, heart failure, and death. Hyperuricemia is an important risk factor that contributes to atrium injury and AF, but the underlying molecular mechanism remains to be elucidated. In this review, we discussed the scientific evidence for clarifying the role of hyperuricemia in the pathogenesis of AF. Experimental and Clinical evidence endorse hyperuricemia as an independent risk factor for the incidence of AF. Various in vivo and in vitro investigations showed that hyperuricemia might play a critical role in the pathogenesis of AF at different UA concentrations through the activation of oxidative stress, inflammation, fibrosis, apoptosis, and immunity.

Genomic and Proteomic Study of the Inflammatory Pathway in Patients With Atrial Fibrillation and Cardiometabolic Syndrome

Atrial fibrillation (AF) and cardiometabolic syndrome (CMS) have been linked to inflammation and fibrosis. However, it is still unknown which inflammatory cytokines contribute to the pathogenesis of AF. Furthermore, cardiometabolic syndrome (CMS) risk factors such as obesity, hypertension, insulin resistance/glucose intolerance are also associated with inflammation and increased level of cytokines and adipokines. We hypothesized that the inflammatory immune response is exacerbated in patients with both AF and CMS compared to either AF or CMS alone. We investigated inflammatory cytokines and fibrotic markers as well as cytokine genetic profiles in patients with lone AF and CMS. CMS, lone AF patients, patients with both lone AF and CMS, and control patients were recruited. Genetic polymorphisms in inflammatory and fibrotic markers were assessed. Serum levels of connective tissue growth factor (CTGF) were tested along with other inflammatory markers including platelet-to-lymphocyte ratio (PLR), monocyte-to-HDL ratio (MHR) in three groups of AF+CMS, AF, and CMS patients. There was a trend in the CTGF levels for statistical significance between the AF and AF+CMS group (P = 0.084). Genotyping showed high percentages of patients in all groups with high secretor genotypes of Interleukin-6 (IL-6) (P = 0.037). Genotyping of IFN-γ and IL-10 at high level showed an increase in expression in the AF + CMS group compared to AF and CMS alone suggesting an imbalance between the inflammatory and anti-inflammatory cytokines which is exacerbated by AF. Serum cytokine inflammatory cytokine levels showed that IL-4, IL-5, IL-10, IL-17F, and IL-22 were significant between the AF, AF+CMS, and CMS patients. Combination of both CMS and AF may be associated with a higher degree of inflammation than what is seen in either CMS or AF alone. Thus, the identification of a biomarker capable of identifying metabolic syndrome associated with disease will help in identification of a therapeutic target in treating this devastating disease.

Yoga as a complementary therapy for metabolic syndrome: A narrative review

Metabolic syndrome (MS) is associated with a sedentary and stressful lifestyle and affects underactive people disproportionately. Yoga is considered to be a low-impact mind-body stress-relieving exercise, and researchers are increasing their focus on the benefits of yoga for managing metabolic disorders. It is also important for physicians and health care professionals to understand the therapeutic efficacy of yoga intervention, in terms of its type, duration and frequency on various MS risk factors. The present review summarizes the current scientific understanding of the effects of yoga on MS risk factors such as glucose homeostasis markers, lipid profile, adipocytokines and cardiovascular risk factors, and discusses the possible mechanisms of action. MEDLINE, PubMed, Scopus and Cochrane Library were searched from their inception up to December 2019, using the keywords "metabolic syndrome," "diabetes," "cardiovascular diseases," "obesity" and "yoga." The literature summarized in this review have shown mixed effects of yoga on MS risk factors and do not provide robust evidence for its efficacy. More rigorous research and well-designed trials that have a higher standard of methodology and evaluate yoga's long-term impacts on MS are needed. Understanding yoga's biochemical and molecular mechanisms of action on various metabolic pathways is also needed.