Lipid levels in midlife and risk of atrial fibrillation over 3 decades-Experience from the Swedish AMORIS cohort: A cohort study

The 2-Step Mendelian Randomisation Study Assesses Genetic Causality and Potential Mediators of Periodontal Disease and Atrial Fibrillation

INTRODUCTION AND AIMS

This study aims to examine the possible causal link between periodontal diseases and atrial fibrillation (AF), with a focus on the modifiable risk factors that facilitate this connection.

METHOD

Firstly, bidirectional and multivariable Mendelian Randomisation (MR) analyses were conducted using genome-wide association studies (GWAS) data on periodontal disease (87,497 cases/259,234 controls) from FinnGen and AF (55,114 cases/482,295 controls) from AFGen. Then, a 2-step MR approach was employed to evaluate the mediating role and proportions of 25 candidate factors among the direct causality between periodontal disease and AF.

RESULTS

Periodontal disease was found to be associated with an increased risk of AF (odds ratio 1.16, 95% CI 1.027-1.314, p = .017), independent of other covariates such as dental caries, pulp, and periapical diseases. Conversely, no causal relationship was detected indicating that AF leads to periodontal disease condition. Furthermore, in the 2-step MR analysis, 5 out of 25 candidate mediators were screened as statistically significant. Ranked by partial mediation proportion, these modifiable mediators included weight (30.3%), IL-17 (17.2%), TNF (14.08%), coronary atherosclerosis (13.4%), and hypertension (11.6%).

CONCLUSION

Our findings demonstrated the genetic causality between periodontal disease and AF. Maintaining oral hygiene, adopting standardised periodontal therapy, and restricting body weight are critical goals for patients with periodontal disease to mitigate disease progression to AF.

Anthropometric indicators of obesity as screening tools for low high-density lipoprotein cholesterol in older adults: A cross-sectional study

Low levels of high-density lipoprotein cholesterol (HDL-C) increase the risk of cardiovascular events and mortality in older individuals. Developing cost-effective screening tools for identifying this condition in large populations is essential. To evaluate the discriminatory capacity of anthropometric indicators of obesity in screening for low HDL-C among older adults. A cross-sectional population-based epidemiological study was conducted with 223 older individuals (57% women) living in a community. The following anthropometric indicators were evaluated: body mass index (BMI), waist circumference (WC), abdominal circumference (AC), body adiposity index (BAI), triceps skinfold (TSF), waist-hip ratio (WHR), waist-height ratio (WHtR), and conicity index (CIn). Low HDL-C was defined as values below 40 mg/dL. The prevalence of low HDL-C was 25.10% (men: 35.41%; women: 21.77%). Among older men, BAI showed the highest sensitivity (87.10%; accuracy: 0.70; 95% CI: 0.53-0.74), while WC had the highest specificity (83.05%; accuracy: 0.71; 95% CI: 0.60-0.80). Among older women, WHR demonstrated the highest sensitivity (100%; accuracy: 0.71; 95% CI: 0.62-0.79), and WHtR showed the highest specificity (67.68%; accuracy: 0.71; 95% CI: 0.62-0.79). BAI and WHR were the most effective indicators for screening older men and women with low HDL-C, respectively. Additionally, WC and WHtR were the most effective indicators for identifying older men and women without low HDL-C, respectively.

Apolipoprotein and sphingolipid measurements: Can be used in the clinical practice of atrial fibrillation diagnosing and evaluating the cryoablation effectiveness?

Atrial fibrillation (AF) has become the most common arrhythmia of clinical importance. A well-established and recommended therapeutic option for AF is the balloon-based cryoablation (CBA) method. There are still no sensitive biomarkers for AF prediction and cryoablation effectiveness assessment, therefore in our prospective study, we examined the plasma content of apolipoproteins (Apo) and sphingolipids, as well as the distribution of selected sphingolipids among lipoprotein fractions. The study included 33 patients with AF on admission and 24 h after cryoablation therapy, while 20 healthy volunteers were recruited to the control group. Plasma Apo concentrations were determined using a multiplex assay kit measuring fluorescence signal, whereas the high-performance liquid chromatography (HPLC) method was applied to assess the total plasma sphingolipid levels as well as their content in isolated lipoprotein fractions. Our results showed that cryoballoon ablation in AF patients markedly reduced the level of almost all Apo compared to the individuals from the control and Pre-CBA groups (Apo-A1: -25.9% and -20.0%, Apo-A2: -19.9% and -17.3%, Apo-B: -26.8% and -14.4%, Apo-C1: -20.3% and -13.4%, Apo-D: -15.9% and -22.2%, Apo-E: -18.3% and -14.3%, and Apo-J: -36.4% and -21.5%, p < 0.05, respectively). Importantly, the area under the curve of Apo-J (AUC 0.81; 95% CI, 0.71-0.92) indicates that it might be a useful biomarker of cryotherapy success in AF patients. Moreover, we also observed a pronounced increase in sphinganine (Sa; +33.5%), sphingosine (So; +24.6%), sphinganine-1-phosphate (Sa1P; +34.3%), and sphingosine-1-phosphate (So1P; +22.3%) concentrations in the Pre-CBA group in comparison with controls. This is the first study that evaluates such a broad panel of Apo and sphingolipids in patients with AF undergoing the CBA procedure, however, to confirm whether any of these parameters could be a clinically useful biomarker for predicting AF or assessing the effectiveness of treatment, further research will be necessary due to limitations of the study.

Elevated Lipoprotein(a) Levels Linked to New-Onset Atrial Fibrillation: Insights from a Retrospective Cohort Study

AIMS

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Although lipoprotein(a) [Lp(a)] is known to be a well-established risk factor for atherosclerotic cardiovascular disease (ASCVD), its role in development of AF, independent of this association, remains unclear.

METHODS

Adult patients from the three Mayo Clinic sites with a baseline Lp(a) and without AF history were included. Patients were categorized into two groups based on their Lp(a) levels: high Lp(a) (≥50 mg/dL) and low Lp(a) (<50 mg/dL). Survival probabilities free from incident AF were compared between Lp(a) groups, during a follow-up period up to 15 years, using the Kaplan-Meier curve and the Log-Rank test. Multivariable Cox regression analysis was also conducted.

RESULTS

A total of 75,376 patients were included (median age: 55 years, 59% males), with a median follow-up duration of 8.8 [inter quartile range (IQR): 3.4, 14.8] years. Incident AF was detected in 5738 (7.6%) patients. Survival probability free from incident AF was significantly lower in patients with elevated Lp(a) (86%) compared with those with low Lp(a) (88%, log rank P<0.001). Multivariable analysis adjusted for potential risk factors of AF showed a statistically significant association of elevated Lp(a) with a 11% increase in AF risk (adjusted HR: 1.11, 95% CI: 1.05 to 1.18).

CONCLUSIONS

Our study suggests that elevated Lp(a) (≥50 mg/dL) is an independent risk factor for incident AF. Future prospective studies are warranted to validate our results and to test the if reducing Lp(a) could mitigate the burden of AF.

Prevalence, risk factors and prognostic value of atrial fibrillation detected after stroke after haemorrhagic versus ischaemic stroke

BACKGROUND AND OBJECTIVES

Prior evidence suggests that atrial fibrillation detected after stroke (AFDAS) is distinct from known atrial fibrillation (KAF), with particular clinical characteristics and impacts on outcomes in ischaemic stroke. However, the results remained inconsistent in ischaemic stroke, and the role of AFDAS in haemorrhagic stroke remains unclear. Therefore, we aimed to estimate the prevalence, risk factors and prognostic value of AFDAS in haemorrhagic stroke in comparison with ischaemic stroke.

METHODS

This was a multicentre cohort study. Patients who had an ischaemic and haemorrhagic stroke hospitalised in the Chinese Stroke Center Alliance hospitals were enrolled and classified as AFDAS, KAF or sinus rhythm (SR) based on heart rhythm. Univariate and multivariate logistic regression analyses were used to assess the prevalence, characteristics, risk factors and outcomes of AFDAS, KAF and SR in different stroke subtypes.

RESULTS

A total of 913 163 patients, including 818 799 with ischaemic stroke, 83 450 with intracerebral haemorrhage (ICH) and 10 914 with subarachnoid haemorrhage (SAH), were enrolled. AFDAS was the most common in ischaemic stroke. There were differences in the risk factor profile between stroke subtypes; older age is a common independent risk factor shared by ischaemic stroke (OR 1.06, 95% CI 1.06 to 1.06), ICH (OR 1.08, 95% CI 1.07 to 1.09) and SAH (OR 1.07, 95% CI 1.05 to 1.10). Similar to KAF, AFDAS was associated with an increased risk of in-hospital mortality compared with SR in both ischaemic stroke (OR 2.23, 95% CI 1.94 to 2.56) and ICH (OR 2.84, 95% CI 1.84 to 4.38).

DISCUSSION

There are differences in the prevalence, characteristics and risk factors for AFDAS and KAF in different stroke subtypes. AFDAS was associated with an increased risk of mortality compared with SR in both ischaemic stroke and ICH. Rhythm monitoring and risk factor modification after both ischaemic and haemorrhagic stroke are essential in clinical practice. More emphasis and appropriate treatment should be given to AFDAS.

Metabolomics in Atrial Fibrillation: Unlocking Novel Biomarkers and Pathways for Diagnosis, Prognosis, and Personalized Treatment

BACKGROUND/OBJECTIVES

Atrial fibrillation (AF) is the most frequent arrhythmia in the adult population associated with a high rate of severe consequences leading to significant morbidity and mortality worldwide. Therefore, its prompt recognition is of high clinical importance. AF detection often remains challenging due to unspecific symptoms and a lack of reliable biomarkers for its prediction. Herein, novel bioanalytical methodologies, such as metabolomics, offer new opportunities for a better understanding of the underlying pathological mechanisms of cardiovascular diseases, including AF. The metabolome, considered a complete set of small molecules present in the organism, directly reflects the current phenotype of the studied system and is highly sensitive to any changes, including arrhythmia's onset. A growing body of evidence suggests that metabolite profiling has prognostic value in AF prediction, highlighting its potential role not only in early diagnosis but also in guiding therapeutic interventions. By identifying specific metabolites as a disease biomarker or recognising particular metabolomic pathways involved in the AF pathomechanisms, metabolomics could be of great clinical value for further clinical decision-making, risk stratification, and an individual personalised approach. The presented narrative review aims to summarise the current state of knowledge on metabolomics in AF with a special emphasis on its implications for clinical practice and personalised medicine.

Smoking timing, genetic susceptibility, and the risk of incident atrial fibrillation: a large prospective cohort study

AIMS

Although smoking is a well-known risk factor for atrial fibrillation (AF), the association of smoking timing with AF risk remains unclear. This study aimed to prospectively investigate the association of smoking timing with the risk of incident AF and test the modification effect of genetic susceptibility.

METHODS AND RESULTS

A total of 305 627 participants with detailed information for time from waking to the first cigarette were enrolled from UK Biobank database. The Cox proportional hazard model was employed to assess the relationship between smoking timing and AF risk. The weighted genetic risk score for AF was calculated. Over a median 12.2-year follow-up, 13 410 AF cases were documented. Compared with non-smokers, time from waking to the first cigarette showed gradient inverse associations with the risk of incident AF (P-trend <0.001). The adjusted hazard ratio related to smoking timing was 1.13 [95% confidence interval (CI): 0.96-1.34] for >120 min, 1.20 (95% CI: 1.01-1.42) for 61-120 min, 1.34 (95% CI: 1.19-1.51) for 30-60 min, 1.43 (95% CI: 1.26-1.63) for 5-15 min, and 1.49 (95% CI: 1.24-1.63) for <5 min, respectively. Additionally, we found that the increased risk of AF related to shorter time from waking to the first cigarette was strengthened by the genetic susceptibility to AF.

CONCLUSION

Our findings suggest gradient inverse association between time from waking to the first cigarette and risk of incident AF, and the association is strengthened by the genetic susceptibility to AF.

Long-Term Statin Use Is Associated With Reduced Rates of Adverse Events in Patients With Newly Diagnosed Atrial Fibrillation

BACKGROUND

The effectiveness of statin use in preventing adverse cardiovascular events in individuals with atrial fibrillation (AF) has remained uncertain. This study aimed to assess whether statin use could lead to better outcomes among individuals with AF.

METHODS AND RESULTS

We enrolled 397 787 patients with AF from January 1, 2012 to December 31, 2020. Patients with AF were divided into 2 groups (statin user and statin nonuser), and the risks of composite outcomes (including ischemic stroke, hemorrhagic stroke, and transient ischemic attack), all-cause death, and major adverse cardiovascular events (which encompassed cardiovascular death, myocardial infarction, stroke, and heart failure hospitalization) were analyzed. We analyzed 288 958 patients with newly diagnosed AF (mean age, 73 years; 44% women; mean CHA2DS2-VASc score, 3.5). Compared with patients without statin use, statin users had lower risks of composite end points (adjusted hazard ratio [HR], 0.91 [95% CI, 0.87-0.94]; P<0.01). In regard to all-cause death, statin users exhibited a 67% risk reduction compared with statin nonusers (adjusted HR, 0.33 [95% CI, 0.32-0.33]; P<0.01). Statin use was also associated with reduced incidence of major adverse cardiovascular events (adjusted HR, 0.64 [95% CI, 0.63-0.66]; P<0.01). In the subgroups stratified by CHA2DS2-VASc score, statin therapy was particularly effective for patients with CHA2DS2-VASc scores 0 to 3 for composite end points but consistently reduced all-cause mortality and major adverse cardiovascular events across all score categories.

CONCLUSIONS

Among patients with newly diagnosed AF, statin use was associated with lower risk of ischemic stroke, hemorrhagic stroke, transient ischemic attack, all-cause mortality, and major adverse cardiovascular events.

Predictors of arrhythmias in the population hospitalized for SARS-CoV-2

BACKGROUND

Studies exploring predictors of arrhythmias in the population primarily hospitalized for SARS-CoV-2 (COVID-19) are scarce. Understanding this is crucial for risk stratification and appropriate management.

METHODS

Using the 2020 National Inpatient Sample (NIS) database, we identified primary admissions for COVID-19. A 'greedy neighbor' 1:1 propensity-score matching (PSM) accounted for baseline differences. Then, multivariable logistic regression models were employed to account for confounders and estimate the probability of arrhythmia.

RESULTS

There were a total of 1,058,815 admissions for COVID-19 (mean age 64.3 years ±16.8), 47.2% female, 52.5% (107698) White, 18.5% (37973) Blacks, and 20.7% (42,447) Hispanics. Atrial fibrillation was the most prevalent arrhythmia, 15.1% (31,942). After PSM, 166,405 arrhythmia hospitalizations were matched to 166,405 hospitalizations without arrhythmia. Sick sinus syndrome 4.9 (4.4-5.5), dyslipidemia 1.2 (1.2-1.3), cardiac arrest 1.3 (1.1-1.4), invasive mechanical ventilation 1.9 (1.8-2.0) and obesity 1.3 (1.2-1.4), (p<0.0001, all) were all independent predictors of arrhythmias.

CONCLUSIONS

Our analysis revealed a notable proportion of hospitalized COVID-19 patients with arrhythmias. Dyslipidemia, obesity, sick sinus syndrome, invasive mechanical ventilation, and cardiac arrest were independent predictors of arrhythmias.

MicroRNAs and other biomarkers of atrial fibrillation in ischemic stroke patients

This study aimed to evaluate the ability of selected microRNAs as biomarkers of atrial fibrillation (AF) in ischemic stroke patients in comparison with other established biochemical biomarkers. A prospective case-control study of consecutive ischemic stroke patients with AF admitted to a comprehensive stroke center was conducted. The control group consisted of patients with ischemic stroke with no AF detected on prolonged (at least 3 weeks) Holter ECG monitoring. As potential biomarkers of AF, we analyzed the plasma levels of microRNAs (miR-21, miR-29b, miR-133b, miR-142-5p, miR-150, miR-499, and miR-223-3p) and 13 biochemical biomarkers at admission. The predictive accuracy of biomarkers was assessed by calculating the area under the receiver operating characteristic curve. The data of 117 patients were analyzed (61 with AF, 56 with no AF, 46% men, median age 73 years, median National Institutes of Health Stroke Scale 6). Biochemical biomarkers (N-terminal pro-B-type natriuretic peptide [NT-proBNP], high-sensitivity cardiac troponin I, fibrinogen, C-reactive protein, eGFR, and total triglycerides) were significantly associated with AF. NT-proBNP had the best diagnostic performance for AF with area under the receiver operating characteristic curve 0.92 (95%, CI 0.86-0.98); a cutoff value of >528 ng/L had a sensitivity of 79% and a specificity of 97%. None of the other biomarkers, including microRNAs, was associated with AF. Conventional biochemical biomarkers (NT-proBNP, high-sensitivity cardiac troponin I, fibrinogen, C-reactive protein, eGFR, and triglycerides), but not microRNAs (miR-21, miR-29b, miR-133b, miR-142-5p, miR-150, miR-499, and miR-223-3p) were significantly associated with AF in our ischemic stroke cohort.

Remnant cholesterol and new-onset atrial fibrillation: The Atherosclerosis Risk in Communities study

BACKGROUND

The relationship between remnant cholesterol (RC) and atrial fibrillation (AF) remains unclear.

OBJECTIVE

The purpose of this study was to comprehensively explore the association between RC characteristics and new-onset AF.

METHODS

Data from 5 follow-up visits of the ARIC (Atherosclerosis Risk in Communities) study were analyzed. RC were multidimensionally evaluated in 4 characteristics: baseline level, variability, cumulative exposure, and trajectory. Baseline RC was obtained from the initial visit (V1), and new-onset AF was monitored in V2 to V5 (cohort 1, n = 14,450). RC variability, cumulative RC, and RC trajectory were calculated by RC values gathered from V1 to V3, and new-onset AF was monitored in V4 and V5 (cohort 2, n = 11,012). Participants were divided into 4 groups based on quartiles or trajectories. Cox proportional hazards analyses were used to investigate the relationship between RC characteristics and AF.

RESULTS

Following median follow-up of 22.39 years in cohort 1 and 16.71 years in cohort 2, a total of 1993 AF events in cohort 1 and 1571 in cohort 2 were identified. Participants with the highest quartile exhibited an elevated risk of new-onset AF, with the multivariable-adjusted hazard ratios of 1.16 (P = .039) for baseline RC and 1.30 (P < .001) for RC variability. Although the highest quartile of cumulative RC (P = .241) and the high-increasing trajectory (P = .210) did not demonstrate a statistically significant association with AF occurrence, they indicate a trend toward heightened risk.

CONCLUSION

Our findings reveal that higher levels of RC, particularly at baseline and in variability, are associated with an increased risk of AF.

Lipoprotein (a) as a Cardiovascular Risk Factor in Controversial Clinical Scenarios: A Narrative Review

Lipoprotein (a) is a complex lipid molecule that has sparked immense interest in recent years, after studies demonstrated its significant association with several cardiovascular conditions. Lp(a) promotes cardiovascular disease through its combined proatherogenic, pro-inflammatory, and prothrombotic effects. While the measurement of Lp(a) has become widely available, effective methods to reduce its concentration are currently limited. However, emerging data from ongoing clinical trials involving antisense oligonucleotides have indicated promising outcomes in effectively reducing Lp(a) concentrations. This may serve as a potential therapeutic target in the management and prevention of myocardial infarction, calcific aortic stenosis, and cerebrovascular accidents. In contrast, the role of Lp(a) in atrial fibrillation, in-stent restenosis, cardiac allograft vasculopathy, and bioprosthetic aortic valve degeneration remains unclear. This review article aims to thoroughly review the existing literature and provide an updated overview of the evidence surrounding the association of Lp(a) and these cardiovascular diseases. We seek to highlight controversies in the existing literature and offer directions for future investigations to better understand Lp(a)'s precise role in these conditions, while providing a summary of its unique molecular characteristics.

Evaluation of the associations of pulmonary vein vertical diameter, cardiothoracic ratio, and atrial fibrillation combined hiatal hernia

Recent studies have suggested that there may be a relationship between hiatal hernia (HH) and atrial fibrillation (AF), but the specific mechanism is unclear. The aim of this study was to explore the clinical characteristics associated with HH and AF and to identify the potential relationship between the 2 diseases. The study comprised 180 patients with HH, of which 54 had AF. Every patient had chest computed tomography to quantify the cardiothoracic ratio, HH volume, thoracic cavity volume, and diameters of the pulmonary veins. The clinical data of all patients was acquired through an electronic medical record system. Patients who experienced AF had a noticeably smaller total pulmonary vein vertical diameter (TPVVD) and a higher cardiothoracic ratio compared to those who only had HH. Logistic multivariate regression study demonstrated a significant association between TPVVD, cardiothoracic ratio, and AF in individuals with HH. This study established a correlation between TPVVD, cardiothoracic ratio, and HH in conjunction with AF. Patient with HH who had a thinner TPVVD and a bigger cardiothoracic ratio were found to have a greater likelihood of suffering from AF.

The predictive value of monocyte-related inflammatory factors for recurrence of atrial fibrillation after cryoablation

Our objective was to investigate the predictive value of monocyte-related inflammatory factors, including monocyte to high-density lipoprotein cholesterol ratio (MHR) and monocyte to lymphocyte ratio (MLR), for the recurrence of atrial fibrillation (AF) after cryoablation in AF patients. The 570 patients who underwent cryoablation were divided into AF recurrence group and non-recurrence group based on follow-up results. The multivariable logistic regression analysis was used to evaluate the effect of MHR and MLR on AF patients. The AF-free survival status of patients was tested by Kaplan-Meier method. ROC analysis was performed to assess the predictive value of MHR and MLR for post-ablation recurrence of AF. A total of 113 (19.8 %) patients relapsed, while 457 patients (80.2 %) had no AF recurrence during follow up. Patients with AF recurrence had higher MHR values (0.37 ± 0.14 vs. 0.33 ± 0.14; P = 0.004) and higher MLR values (0.49 ± 0.32 vs. 0.18 ± 0.07; P < 0.001) compared to those without AF recurrence. MHR≥0.34 combined with MLR≥0.24 (HR = 9.979, 95 % CI: 6.070-16.407, P < 0.001) was an independent factor for predicting AF recurrence after cryoablation in patients by logistic regression analysis. The ROC analysis showed that the AUC for the combination of the MHR and MLR variables was 0.974 (95 % CI: 0.962-0.985) and had the highest diagnostic sensitivity (97.4 %). Elevated baseline values of the monocyte-related inflammatory factors, MHR and MLR, have a certain predictive value for increased AF recurrence after cryoablation.

Atrial Fibrillation Prevalence Rates and Its Association with Cardiovascular-Kidney-Metabolic Factors: SIMETAP-AF Study

Background and Objectives: Atrial fibrillation (AF) is the most frequent arrhythmia and the main cause of hospital admissions for cardioembolic stroke. The SIMETAP research project aims to update the prevalence rates of cardiovascular, renal, or metabolic factors and to evaluate their respective associations with factors that could be related. The present study aims to assess the AF prevalence rates in an adult population and its association with cardiovascular-kidney-metabolic (CKM) factors. Materials and Methods: This cross-sectional observational study was conducted in a primary care setting, with a population-based random sample of 6588 people aged 18.0-102.8 years. Crude and adjusted prevalence rates of AF were calculated. The associations of CKM factors with AF were assessed using bivariate and multivariate analysis. Results: The age- and sex-adjusted prevalence rates of AF were 2.9% in the overall adult population, 6.1% in the population aged ≥50 years, and 12.9% in the population aged ≥70 years, with no significant differences by sex. AF prevalence in the population under 50 years of age barely reached 1‰. Heart failure (HF), hypertension, chronic kidney disease (CKD), stroke, low HDL-cholesterol, and prediabetes were independent CKM factors associated with AF in the overall population, as were the same factors, except prediabetes, in the population ≥50 years old (p < 0.001). High or very high vascular risk was present in 92.4% [95% CI: 89.1-95.7]) of the population with AF. Conclusions: The adjusted prevalence rate of AF in the population aged 50 years or older was 6.1%, twice that of the overall adult population and half that of the population aged 70 years or older. The main independent CKM factors associated with AF were HF, stroke, CKD, hypertension, and low HDL-cholesterol.

Atrial fibrillation: comorbidities, lifestyle, and patient factors

Modern anticoagulation therapy has dramatically reduced the risk of stroke and systemic thromboembolism in people with atrial fibrillation (AF). However, AF still impairs quality of life, increases the risk of stroke and heart failure, and is linked to cognitive impairment. There is also a recognition of the residual risk of thromboembolic complications despite anticoagulation. Hence, AF management is evolving towards a more comprehensive understanding of risk factors predisposing to the development of this arrhythmia, its' complications and interventions to mitigate the risk. This review summarises the recent advances in understanding of risk factors for incident AF and managing these risk factors. It includes a discussion of lifestyle, somatic, psychological, and socioeconomic risk factors. The available data call for a practice shift towards a more individualised approach considering an increasingly broader range of health and patient factors contributing to AF-related health burden. The review highlights the needs of people living with co-morbidities (especially with multimorbidity), polypharmacy and the role of the changing population demographics affecting the European region and globally.

Association Between Lipoprotein (a) and Risk of Atrial Fibrillation: A Systematic Review and Meta-analysis of Mendelian Randomization Studies

Lipoprotein (a) (Lp[a]) is an established risk factor for atherosclerotic cardiovascular disease (ASCVD). However, data on association of Lp(a) with risk of atrial fibrillation (AF) is still limited. We searched PubMed/Medline, Scopus, and EMBASE for studies evaluating the association of Lp(a) with the occurrence of AF until July 2023. Random effects models and I2 statistics were used for pooled odds ratios (OR), and heterogeneity assessments. A subgroup analysis was performed based on the cohort population, and a one-out sensitivity analysis was performed. This meta-analysis comprised 275,647 AF cases and 2,100,172 Lp(a) participants. An increase in Lp(a) was associated with an increased risk of AF in mendelian randomization (MR) studies (OR 1.024, 95% CI: 1.007-1.042, I2 = 87.72%, P < 0.001). Leave-one-out sensitivity analysis confirmed equivalent results in MR studies. Subgroup analysis of MR studies revealed a higher risk of AF in the European cohort (OR 1.023, 95% CI: 1.007-1.040, I2 = 89.05%, P < 0.001) and a low risk (OR 0.940, 95% CI: 0.893-0.990) in the Chinese population. Meta-analysis of the MR data suggested higher levels of Lp(a) were associated with increased risk of AF. Future robust prospective studies are warranted to validate these findings.

SGLT2 inhibition, circulating metabolites, and atrial fibrillation: a Mendelian randomization study

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown promise in reducing the risk of atrial fibrillation (AF). However, the results are controversial and the underlying metabolic mechanism remains unclear. Emerging evidence implied that SGLT2 inhibitors have extra beneficial metabolic effects on circulating metabolites beyond glucose control, which might play a role in reducing the risk of AF. Hence, our study aimed to investigate the effect of circulating metabolites mediating SGLT2 inhibition in AF by Mendelian randomization (MR).

METHODS

A two-sample and two-step MR study was conducted to evaluate the association of SGLT2 inhibition with AF and the mediation effects of circulating metabolites linking SGLT2 inhibition with AF. Genetic instruments for SGLT2 inhibition were identified as genetic variants, which were both associated with the expression of SLC5A2 gene and glycated hemoglobin level (HbA1c). Positive control analysis on type 2 diabetes mellitus (T2DM) was conducted to validate the selection of genetic instruments.

RESULTS

Genetically predicted SGLT2 inhibition (per 1 SD decrement in HbA1c) was associated with reduced risk of T2DM (odds ratio [OR] = 0.63 [95% CI 0.45, 0.88], P = 0.006) and AF (0.51 [0.27, 0.97], P = 0.039). Among 168 circulating metabolites, two metabolites were both associated with SGLT2 inhibition and AF. The effect of SGLT2 inhibition on AF through the total concentration of lipoprotein particles (0.88 [0.81, 0.96], P = 0.004) and the concentration of HDL particles (0.89 [0.82, 0.97], P = 0.005), with a mediated proportion of 8.03% (95% CI [1.20%, 14.34%], P = 0.010) and 7.59% ([1.09%, 13.34%], P = 0.011) of the total effect, respectively.

CONCLUSIONS

This study supported the association of SGLT2 inhibition with a reduced risk of AF. The total concentration of lipoprotein particles and particularly the concentration of HDL particles might mediate this association. Further mechanistic and clinical studies research are needed to understand the mediation effects of circulating metabolites especially blood lipids in the association between SGLT2 inhibition and AF.

Meta-analysis of the Current Research on the Relationship Between Blood Lipid Levels and the Occurrence of Atrial Fibrillation

BACKGROUND

There is still debate in the literature about the relationship between lipid profile and the occurrence of atrial fibrillation (AF). In order to assess the association between blood lipid profiles and incidence of AF, this review was conducted to perform a meta-analysis of all available studies.

METHODS

This review analysed all studies up to 28 February 2023 in PubMed, Google Scholar, and the Cochrane Library that included data regarding blood lipid levels and incidence of AF. For the purpose of calculating pooled estimates, the hazard ratios were extracted from all studies.

RESULTS

Fourteen studies including 19 cohorts with 3,990,484 patients were included in this meta-analysis. An elevation of one standard deviation in total cholesterol (TC) level was associated with an 8% reduction (HR=0.92, 0.88-0.96; p<0.01) in the risk of developing AF. Although increased low-density lipoprotein cholesterol levels were associated with a 7% reduction in the development of AF (HR=0.93, 0.87-1.00; p=0.04), there was high heterogeneity in the random effects model (I2=92%). Changes in high-density lipoprotein cholesterol and triglyceride levels were not found to be associated with AF risk in the pooled analysis. Dose-response meta-analysis showed that TC was inversely linearly associated with the risk of AF (p<0.001).

CONCLUSIONS

Higher TC levels were shown to be independently attributed to an increased risk of AF in individuals without cardiovascular disease. There was no association between the incidence of AF and triglyceride, high-density lipoprotein cholesterol, or low-density lipoprotein cholesterol blood levels.

Associations of risk factor burden and genetic predisposition with the 10-year risk of atrial fibrillation: observations from a large prospective study of 348,904 participants

BACKGROUND

Understanding the effects of risk factor burden and genetic predisposition on the long-term risk of atrial fibrillation (AF) is important to improve public health initiatives. However, the 10-year risk of AF considering risk factor burden and genetic predisposition is unknown.

METHODS

A total of 348,904 genetically unrelated participants without AF at baseline from the UK were categorized into three groups: index ages 45 years (n = 84,206), 55 years (n=117,520), and 65 years (n=147,178). Optimal, borderline, or elevated risk factor burden was determined by body mass index, blood pressure, diabetes mellitus, alcohol consumption, smoking status, and history of myocardial infarction or heart failure. Genetic predisposition was estimated using the polygenic risk score (PRS), constructed using 165 predefined genetic risk variants. The combined effects of risk factor burden and PRS on the risk of incident AF in 10 years were estimated for each index age. Fine and Gray models were developed to predict the 10-year risk of AF.

RESULTS

The overall 10-year risk of AF was 0.67% (95% CI: 0.61-0.73%) for index age 45 years, 2.05% (95% CI: 1.96-2.13%) for index age 55 years, and 6.34% (95% CI: 6.21-6.46%) for index age 65 years, respectively. An optimal risk factor burden was associated with later AF onset regardless of genetic predisposition and sex (P < 0.001). Significant synergistic interactions were observed for risk factor burden with PRS at each index age (P < 0.05). Participants with an elevated risk factor burden and high PRS had the highest 10-year risk of AF in reference to those who had both an optimal risk factor burden and a low PRS. At younger ages, optimal risk burden and high PRS might also lead to later onset of AF, compared to the joint effect of elevated risk burden and low/intermediate PRS.

CONCLUSIONS

Risk factor burden together with a genetic predisposition is associated with the 10-year risk of AF. Our results may be helpful in selecting high-risk individuals for primary prevention of AF and facilitating subsequent health interventions.