Occurrence Of Persistent Atrial Fibrillation Research Articles

Strong Positive Correlations Between the Levels of Systemic Inflammation Markers and the Occurrence of Persistent Atrial Fibrillation.

In this study, a retrospective analysis was conducted to investigate the associations between systemic inflammation markers and persistent atrial fibrillation (pAF), intending to identify potential biomarkers for early detection of pAF.In the analysis, a total of 207 patients were included, with 109 in the pAF group and 98 in the non-pAF group. The associations between three systemic inflammation markers were investigated, namely, the systemic immune inflammation index (SII), system inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI), and pAF.The proportion of pAF showed a gradual increase with increasing logSII, logSIRI, and logAISI tertiles. Compared with those in the lowest tertiles, those in the highest logSII and logSIRI tertiles had 3.196- and 2.884-fold higher risks of developing pAF, respectively. Nonetheless, no significant correlation between logAISI and pAF risk was observed in the highest tertile of logAISI. The restricted cubic spline analysis revealed a nonlinear relationship between the elevation of systemic inflammation markers and the risk of pAF, with logSII ≥ 2.56, logSIRI ≥ -0.10, and logAISI ≥ 2.28 identified as significant predictors. The receiver operating characteristic analysis of logSII, logSIRI, and logAISI showed AUC values of 0.629, 0.721, and 0.646, respectively. It also presented favorable sensitivity and specificity of these systemic inflammation markers in detecting the presence of pAF.To conclude, our cross-sectional study shows significant positive correlations between the SII, SIRI, and AISI with the incidence of pAF.

Impact of clinical risk factor profile vs. atrial fibrillation phenotype on outcome after pulmonary vein isolation

Abstract Aims Catheter ablation for atrial fibrillation (AF) is increasingly performed. Both clinical risk factors as well as the AF phenotype have been shown to influence ablation outcomes. The inter-relationship of the two however is incompletely understood. Methods In a retrospective analysis of a prospective registry of patients undergoing a first pulmonary vein isolation, the association of 8 predefined clinical risk factors (age >70 years, female gender, hypertension, BMI >30 kg/m2, coronary artery disease, heart failure, chronic kidney disease (CKD; eGFR<60ml/min/1.73m2) and diabetes mellitus) and the AF phenotype (paroxysmal vs. persistent AF) were assessed as well as their impact on AF recurrence during follow-up. Results Overall, 715 patients were enrolled (median age 63 years, 27% females, 69% paroxysmal AF). The prevalence of obesity, hypertension, heart failure and CKD was significantly higher in persistent AF, while female gender was more prevalent in paroxysmal AF. After 2 years of follow-up, overall freedom from recurrence was 46%, and was higher in paroxysmal AF compared to persistent AF (54.1% vs. 29.1%, p<0.001). Of the clinical risk factors, obesity (p=0.02), CKD (p=0.01) and heart failure (p=0.01) were significantly associated with lower arrhythmia-free survival, and there was a trend for hypertension and coronary artery disease (both p<0.2). A risk score composed of those 5 factors was associated with recurrences in patients with paroxysmal AF (p=0.04, Figure 1), but not in those with persistent AF (p=0.85, Figure 2). Conclusion Clinical risk factors predict outcome after pulmonary vein isolation in patients with paroxysmal, but not persistent AF. This is likely due to a strong association of those risk factors with the occurrence of persistent AF. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

Occurrence of persistent atrial fibrillation during pacing for sinus node disease: The influence of His bundle pacing versus managed ventricular pacing.

In patients with sinus node disease (SND), the dual-chamber pacemaker (PM) is programmed in DDDR mode with an algorithm to avoid unnecessary right ventricular (RV) pacing. This pacing mode may prolong PR interval with consequently atrioventricular (AV) asynchrony which is associated with a higher risk of atrial fibrillation (AF). We evaluate whether preserving AV synchrony by setting a fixed AV delay during physiological RV pacing, that is,His bundle pacing (HBP), could reduce the risk of AF occurrence in comparison with a standard pacing mode with an algorithm to avoid unnecessary RV pacing (DDD-VPA). We collected retrospective data from 313 consecutive patients who had undergone PM for SND. The first occurrence of persistent AF (>7 consecutive days) as a function of the pacing mode was evaluated. HBP and DDD-VPA were implemented in 82 and 231 patients, respectively. Persistent AF occurred in 128 (40.9%) patients over a median follow-up of 70 months (67-105). The DDD-VPA pacing mode was significantly correlated with the occurrence of persistent AF only when the basal PR was long (>180 ms). The risk of persistent AF was significantly lower in patients on HBP than in those on DDD-VPA, adjusted HR = .57 (95% CI, .36- .89, p=.014). Other independent predictors of persistent AF occurrence were: A history of AF (HR = 3.91; 95% CI, 2.48-6.19, p = .001), age, and long PR interval (HR = 2.98; 95% CI, 2.00-4.43, p=.001). In SND patients and long basal PR interval, the HBP may reduce the risk of persistent AF in comparison with the DDD-VPA.

P935Can we predict the occurrence of persistent atrial fibrillation in large animal models to improve study efficiency?

Abstract Funding Acknowledgements British Heart Foundation Project Grant FS/17/54/33126 Background A key consideration when using animals in research is maximising experimental efficiency to minimise the number of animals required. Large animal models have proven an invaluable tool for establishing pathophysiological mechanisms underpinning atrial fibrillation (AF) and testing novel therapeutics, however animals may be resistant to developing the arrhythmias required. While the relationships between atrial refractory periods, conduction velocity, surface area, and vulnerability to fibrillation have been established in clinical practice, these parameters are not regularly used to design animal studies of persistent AF (PsAF). Purpose We investigated whether routinely collected baseline parameters could be used to improve experimental efficiency in an ovine model, by predicting the development of PsAF as opposed to arrhythmia resistance. The aims were to: reduce the number of animals used in future studies, and avoid prolonged experiments in animals likely to be resistant to AF. Methods All procedures were conducted with respect to the Animals [Scientific Procedures] Act, UK, 1986; and were approved by the local ethical review board. The ovine model consisted of healthy adult Welsh mountain sheep that underwent implantation of a neurostimulator connected via an endocardial pacing lead to the right atrial appendage. The device was programmed to deliver intermittent 30 second bursts of 50Hz and sheep were monitored over an eight week period for PsAF. Eight variables were collected at time of implant including weight (kg), left atrial diameter (LAD; cm), P wave duration (msec), PR interval (msec), atrial effective refractory period (ERP; msec), atrial conduction velocity (CV; m/s), AF inducibility with 50Hz bursts (secs), and rate threshold of atrial action potential alternans (msec). Analysis of the data was performed using multiple logistic regression and receiver-operator characteristic (ROC) curves. Regression coefficients are presented as natural logarithm of odds ratios (OR) with 95% confidence intervals (CI). Results Seventeen sheep were included in this study. Five (29%) developed PsAF whereas twelve (71%) were resistant (non-sustained or no AF). Univariate analysis found none of the parameters alone could predict PsAF, however ERP (OR -0.05, CI -.01 to 0.01, p = 0.089) and LAD (OR 8.1, CI -1.6 to 17.5, p = 0.095) suggested a combination may be predictive. A multivariate analysis using Fibrillation number (calculated as LAD / [ERP X CV]) was predictive (OR 26.9, CI 1.1 to 52.7; p = 0.04], with an area under ROC curve of 0.85 (p = 0.027). Conclusions Fibrillation number can predict the development of PsAF in healthy sheep. Practically speaking, this means animals with: a larger LAD, shorter ERP and slower CV are more likely to develop PsAF. These findings can be used to optimise the design of future studies, particularly by reducing the number of animals required.

Residual Arrhythmogenic Foci Predict Recurrence in Long-Standing Persistent Atrial Fibrillation Patients After Sinus Rhythm Restoration Ablation

BackgroundThe mechanism of persistent atrial fibrillation (AF) is multifactorial, and arrhythmogenic foci (AMF) might be involved in the occurrence of persistent AF. In this study, we examined the electrophysiological features of AMF during and immediately after ablation, and evaluated the relationship between the presence and number of residual AMF on the risk of AF recurrence after a vigorous sinus rhythm restoration ablation in patients with long-standing persistent AF. MethodsThe study consisted of 117 consecutive patients with persistent AF who underwent catheter ablation (CA). We performed direct cardioversion to restore sinus rhythm before the pulmonary vein (PV) isolation and at the end of the CA. Then we evaluated the features of the AMF inducible with isoproterenol and the pacing-based AF inducibility. ResultsAfter the completion of ablation, AF could still be induced in 37 of 117 patients (31.6%). Spontaneous PV AMF during CA were observed in 104 of 117 patients (91%), and non-PV AMF in 63 of 117 (54%). Residual non-PV AMF were significantly associated with the pacing-based AF inducibility and an enlarged left atrial volume. In the multivariate analysis, the AF duration (1.01 [range, 1.00-1.02] months; P = 0.012), left atrial volume (1.01 [range, 1.01-1.02] mm; P = 0.006), and residual AMF (3.95 [range, 1.32-11.8] yes, no; P = 0.004) were independent risk factors for recurrent AF. ConclusionsResidual AMF are associated with an increased long-term AF recurrence after sinus rhythm restoration ablation for long-standing persistent AF.

Prospective Randomized Study to Assess the Efficacy of Site and Rate of Atrial Pacing on Long-Term Progression of Atrial Fibrillation in Sick Sinus Syndrome

Background— Atrial-based pacing is associated with lower risk of atrial fibrillation (AF) in sick sinus syndrome compared with ventricular pacing; nevertheless, the impact of site and rate of atrial pacing on progression of AF remains unclear. We evaluated whether long-term atrial pacing at the right atrial (RA) appendage versus the low RA septum with (ON) or without (OFF) a continuous atrial overdrive pacing algorithm can prevent the development of persistent AF. Methods and Results— We randomized 385 patients with paroxysmal AF and sick sinus syndrome in whom a pacemaker was indicated to pacing at RA appendage ON (n=98), RA appendage OFF (n=99), RA septum ON (n=92), or RA septum OFF (n=96). The primary outcome was the occurrence of persistent AF (AF documented at least 7 days apart or need for cardioversion). Demographic data were homogeneous across both pacing site (RA appendage/RA septum) and atrial overdrive pacing (ON/OFF). After a mean follow-up of 3.1 years, persistent AF occurred in 99 patients (25.8%; annual rate of persistent AF, 8.3%). Alternative site pacing at the RA septum versus conventional RA appendage (hazard ratio=1.18; 95% confidence interval, 0.79–1.75; P =0.65) or continuous atrial overdrive pacing ON versus OFF (hazard ratio=1.17; 95% confidence interval, 0.79–1.74; P =0.69) did not prevent the development of persistent AF. Conclusions— In patients with paroxysmal AF and sick sinus syndrome requiring pacemaker implantation, an alternative atrial pacing site at the RA septum or continuous atrial overdrive pacing did not prevent the development of persistent AF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00419640.