Ablation of atrial fibrillation and dementia risk reduction during long-term follow-up: a nationwide population-based study

Impact of Helicobacter pylori and metabolic syndrome on mast cell activation-related pathophysiology and neurodegeneration

Both Helicobacter pylori (H. pylori) infection and metabolic syndrome (MetS) are highly prevalent worldwide. The emergence of relevant research suggesting a pathogenic linkage between H. pylori infection and MetS-related cardio-cerebrovascular diseases and neurodegenerative disorders, particularly through mechanisms involving brain pericyte deficiency, hyperhomocysteinemia, hyperfibrinogenemia, elevated lipoprotein-a, galectin-3 overexpression, atrial fibrillation, and gut dysbiosis, has raised stimulating questions regarding their pathophysiology and its translational implications for clinicians. An additional stimulating aspect refers to H. pylori and MetS-related activation of innate immune cells, mast cells (MC), which is an important, often early, event in systemic inflammatory pathologies and related brain disorders. Synoptically, MC degranulation may play a role in the pathogenesis of H. pylori and MetS-related obesity, adipokine effects, dyslipidemia, diabetes mellitus, insulin resistance, arterial hypertension, vascular dysfunction and arterial stiffness, an early indicator of atherosclerosis associated with cardio-cerebrovascular and neurodegenerative disorders. Meningeal MC can be activated by triggers including stress and toxins resulting in vascular changes and neurodegeneration. Likewise, H.pylori and MetS-related MC activation is linked with: (a) vasculitis and thromboembolic events that increase the risk of cardio-cerebrovascular and neurodegenerative disorders, and (b) gut dysbiosis-associated neurodegeneration, whereas modulation of gut microbiota and MC activation may promote neuroprotection. This narrative review investigates the intricate relationship between H. pylori infection, MetS, MC activation, and their collective impact on pathophysiological processes linked to neurodegeneration. Through a comprehensive search of current literature, we elucidate the mechanisms through which H. pylori and MetS contribute to MC activation, subsequently triggering cascades of inflammatory responses. This highlights the role of MC as key mediators in the pathogenesis of cardio-cerebrovascular and neurodegenerative disorders, emphasizing their involvement in neuroinflammation, vascular dysfunction and, ultimately, neuronal damage. Although further research is warranted, we provide a novel perspective on the pathophysiology and management of brain disorders by exploring potential therapeutic strategies targeting H. pylori eradication, MetS management, and modulation of MC to mitigate neurodegeneration risk while promoting neuroprotection.

Atrial fibrillation increases the risk of all-cause dementia, Alzheimer's disease, and vascular dementia: A cohort study of 373, 415 participants in the UK Biobank

BACKGROUND

Accumulated evidence has highlighted the association between atrial fibrillation and the risk of developing dementia.

METHODS

This current cohort study utilized data from the UK Biobank to explore the association between atrial fibrillation (AF) and all-cause dementia (ACD), encompassing its main subtypes (Alzheimer's disease (AD), and vascular dementia (VD)). Cox proportional hazards models were applied to examine the association of AF and dementia with its primary subtypes after adjusting for different sets of covariates. Hazard ratios (HRs) with 95 % confidential intervals (CIs) were estimated to quantify the associated risks. Competing risk model was applied in sensitivity analysis.

RESULTS

After exclusion, 373, 415 participants entered the primary analysis. Among these, 27, 934 (7.48 %) were with a history AF at baseline, while 345, 481 (92.52 %) were without. During a mean follow-up of 13.45 years, ACD was diagnosed in 1215 individuals with AF and 3988 individuals without AF. Participants with AF had higher risks of ACD (1.79 [1.67-1.91]), AD (1.48 [1.32-1.65]), and VD (2.46 [2.17-2.80]) in the fully adjusted Cox regression models. Results of subgroup and sensitivity analyses predominantly aligned with the positive associations in primary analysis.

LIMITATIONS

The applicability of our findings to diverse ethnicities might require careful consideration and the behind biological mechanisms need to be further revealed.

CONCLUSIONS

It indicated that people with atrial fibrillation had an increased future risk of all-cause dementia, Alzheimer's disease, vascular dementia. Atrial fibrillation screening and prevention strategies should take into account to prevent and delay the onset of dementia.

Reduced dementia risk in patients with optimized anticoagulation therapy undergoing atrial fibrillation ablation

BACKGROUND

Atrial fibrillation (AF) is associated with the development of dementia, and observational studies have shown that oral anticoagulation and catheter ablation reduce dementia risk. However, such studies did not consistently report on periprocedural anticoagulation and long-term oral anticoagulation coverage, for which reason the separate effect of AF ablation on dementia risk could not be established.

OBJECTIVE

We evaluated the protective effect of AF ablation in a large cohort of patients who received optimized anticoagulation and compared them with patients who were managed medically.

METHODS

We retrospectively included 5912 consecutive patients who underwent first-time catheter ablation for AF between 2008 and 2018 and compared them with 52,681 control individuals from the Swedish Patient Register. Propensity score matching produced 2 cohorts of equal size (n = 3940) with similar baseline characteristics. Dementia diagnosis was identified by International Classification of Diseases codes from the patient register.

RESULTS

Most propensity score-matched patients were taking an oral anticoagulant at the start (94.5%) and end (75.0%) of the study. Mean follow-up was 4.9 ± 2.8 years. Catheter ablation was associated with lower risk for the dementia diagnosis compared with the control group (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.22-0.86; P = .017). The result was similar when including patients with a stroke diagnosis before inclusion (HR, 0.50; 95% CI, 0.28-0.89; P = .019) and after adjustment for the competing risk of death (HR, 0.41; 95% CI, 0.20-0.86; P = .018).

CONCLUSION

Catheter ablation of AF in patients with optimized oral anticoagulation therapy was associated with a reduction in dementia diagnosis, even after adjustment for potential confounders and for competing risk of death.

Effects of rhythm-control and rate-control strategies on cognitive function and dementia in atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Growing evidence suggests that atrial fibrillation (AF) is an independent risk factor for cognitive impairment and dementia, even in the absence of thromboembolic events and stroke. Whether rhythm-control therapy can protect cognitive function remains unclear. We aimed to evaluate the efficacy of rhythm-control strategies in patients with AF regarding cognitive function and dementia risk.

METHODS

We systematically searched the PubMed, Embase and Cochrane Library databases for randomised clinical trials, cohort and case-control studies evaluating the associations between rhythm-control strategies and cognitive function outcomes up to May 2023. We assessed the risk of bias using the ROBINS-I and the Cochrane risk-of-bias tool. Both fixed- and random-effects models were used to create summary estimates of risk.

RESULTS

We included a total of 14 studies involving 193,830 AF patients. In the pooled analysis, compared with rate-control, rhythm-control therapy was significantly associated with a lower risk of future dementia (hazard ratio (HR) 0.74; 95% confidence interval (CI) 0.62-0.89; I2 = 62%). Among the rhythm-control strategies, AF ablation is a promising treatment that was related to significantly lower risks of overall dementia (HR 0.62; 95% CI 0.56-0.68; I2 = 42%), Alzheimer's disease (HR 0.78; 95% CI 0.66-0.92; I2 = 0%) and vascular dementia (HR 0.58; 95% CI 0.42-0.80; I2 = 31%). Pooled results also showed that compared with patients without ablation, those who underwent AF ablation had significantly greater improvement in cognitive score (standardized mean difference (SMD) 0.85; 95% CI 0.30-1.40; P = 0.005; I2 = 76%).

CONCLUSIONS

Rhythm-control strategies, especially ablation, are effective in protecting cognitive function, reducing dementia risk and thus improving quality of life in AF patients.

Epidemiology, Trends, Utilization Disparities, and Outcomes of Catheter Ablation and Its Association With Coronary Vasospasm Amongst Patients With Non-valvular Atrial Fibrillation: A Nationwide Burden of Last Decade

BACKGROUND

Catheter ablation (CA) is an important curative treatment for non-valvular atrial fibrillation (NVAF), however, nationwide data on its utilization and disparities is limited. Coronary vasospasm is a rare, life-threatening, peri-operative complication of CA with limited literature in Caucasians.

METHODS

We performed a retrospective study on adult hospitalizations in the USA from 2007 to 2017 by obtaining the data from National Inpatient Sample. The primary endpoints of our study were to identify the utilization rate of CA, disparities in utilization, and study the outcomes associated with CA. The secondary endpoints of the study were to identify the incidence of coronary vasospasm amongst patients who underwent CA, evaluate their association, and identify the predictors of coronary vasospasm.

RESULTS

From 35,906,946 patients with NVAF, 343641 (0.96%) underwent CA. Its utilization decreased from 1% in 2007 to 0.71% in 2017. Patients who underwent CA, compared to those without CA, fared better in terms of hospital length of stay, mortality rate, disability rate, and discharge to the non-home facility. Patients in the 50-75 years age group, Native Americans, those with private insurance, and median household income of 76-100th percentile were associated with higher odds of CA utilization. Urban teaching hospitals and large-bedded hospitals performed more ablations, while the Mid-West region fared lower than the South, the West, and the Northeast. The prevalence of coronary vasospasm was higher amongst CA in comparison without CA, however, in regression analysis, no significant association was demonstrated between CA and coronary vasospasm.

CONCLUSION

CA is an important treatment modality that is associated with improved clinical outcomes. Identification of factors associated with lower utilization of CA and its disparities will help to mitigate the burden associated with NVAF.