Effect of concomitant Renal DeNervation and cardiac ablation on Atrial Fibrillation recurrence - RDN+AF study

BACKGROUND

Renal denervation (RDN) can reduce cardiac sympathetic activity maintained by arterial hypertension (aHT). Its potential antiarrhythmic effect on rhythm outcome in patients with multi-drug resistant aHT undergoing catheter ablation for atrial fibrillation (AF) is unclear.

METHODS

The RDN+AF study was a prospective, randomized, two-center trial. Patients with paroxysmal or persistent AF and uncontrolled aHT (mean systolic 24-h ambulatory BP > 135 mmHg) despite taking at least three antihypertensive drugs were enrolled. Patients were 1:2 randomized to either RDN+AF ablation or AF-only ablation. Primary endpoint was freedom from any AF episode > 2 min at 12 months assessed by implantable loop recorder (ILR) or 7d-holter electrocardiogram. Secondary endpoints included rhythm outcome at 24 months, blood pressure control, periprocedural complications, and renovascular safety.

RESULTS

The study randomized 61 patients (mean age 65 ± 9 years, 53% men). At 12 months, RDN+AF patients tended to have a greater decrease in ambulatory BPs but did not reach statistical significance. No differences in rhythm outcome were observed. Freedom from AF recurrence in the RDN+AF and AF-only group measured 61% versus 53% p = .622 at 12 months and 39% versus 47% p = .927 at 24 months, respectively. Periprocedural complications occurred in 9/61 patients (15%). No patient died.

CONCLUSION

Among patients with multidrug-resistant aHT and paroxysmal or persistent AF, concomitant RDN+AF ablation was not associated with better blood pressure control or rhythm outcome in comparison to AF-only ablation and medical therapy.

Low-Voltage Myocardium-Guided Ablation Trial of Persistent Atrial Fibrillation

Low-Voltage Myocardium Ablation Trial of Persistent AFWe investigated ablation approaches in 324 patients with persistent AF by comparing ablation with PVI alone and PVI plus individualized SM. Patients had electrocardiogram recordings over 12 months of observation. Recurrent AF was documented in 50% of PVI only and 35% of PVI+SM patients. AEs occurred in six PVI+SM versus three PVI-alone patients.

Left Atrial Isolation and Appendage Occlusion in Patients With Atrial Fibrillation at End-Stage Left Atrial Fibrotic Disease

[Figure: see text].

Left atrial phasic transport function closely correlates with fibrotic and arrhythmogenic atrial tissue degeneration in atrial fibrillation patients: cardiac magnetic resonance feature tracking and voltage mapping

AIMS

To characterize the association of phasic left atrial (LA) transport function and LA fibrosis guided by multimodality imaging containing cardiac magnetic resonance imaging (CMR) feature tracking and bipolar voltage mapping.

METHODS AND RESULTS

Consecutive patients presenting for first-time ablation of atrial fibrillation (AF) were prospectively enrolled. Each patient underwent CMR prior to the ablation procedure. LA phasic indexed volumes (LA-Vi) and emptying fractions (LA-EF) were calculated and CMR feature tracking guided LA wall motion analysis was performed. LA bipolar voltage mapping was carried out in sinus rhythm to find areas of low voltage as a surrogate for fibrosis and arrhythmogenesis. One hundred and sixty-eight patients were enrolled. Low-voltage areas (LVAs) were present in 70 patients (42%). Contrary to LA volume, CMR based LA-EF [odds ratio (OR) 0.88, 95% confidence interval (CI) 0.80-0.96, P = 0.005] and LA booster pump strain rate (SR) (OR 0.98, 95% CI 0.97-0.99, P = 0.001) significantly predicted presence and extent of LVA in multivariate logistic regression analysis for patients scanned in SR. In receiver operating characteristic analysis, LA-EF <40% carried a sensitivity of 83% and specificity of 76% (area under the curve 0.8; 95% CI 0.71-0.89) to predict presence of LVA. For patients scanned in AF only minimal LA-Vi on CMR (OR: 1.06; 95% CI: 1.02-1.10; P = 0.002) predicted presence of LVA.

CONCLUSION

For patients scanned in SR LA-EF and LA booster pump SR are closely linked to the presence and extent of LA LVA.

Left atrial fibrosis predicts left ventricular ejection fraction response after atrial fibrillation ablation in heart failure patients: the Fibrosis-HF Study

Aims

Atrial fibrillation (AF) and heart failure (HF) often coexist. Catheter ablation has been reported to restore left ventricular (LV) function but patients benefit differently. This study investigated the correlation between left atrial (LA) fibrosis extent and LV ejection fraction (LVEF) recovery after AF ablation.

Methods and results

In this study, 103 patients [64 years, 69% men, 79% persistent AF, LVEF 33% interquartile range (IQR) (25–38)] undergoing first time AF ablation were investigated. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. Continuous rhythm monitoring was used to assess ablation success. Improvement in post-ablation LVEF was measured as primary study endpoint. An absolute increase in post-ablation LVEF ≥10% was defined as ‘Super Response’. Left atrial fibrosis was present in 38% of patients. After ablation LVEF increased by absolute 15% (IQR 6–25) (P &lt; 0.001). Left ventricular ejection fraction improvement was higher in patients without LA fibrosis [15% (IQR 10–25) vs. 10% (IQR 0–20), P &lt; 0.001]. An inverse correlation between LVEF improvement and the extent of LA fibrosis was found (R2 = 0.931). In multivariate analysis, the presence of LA fibrosis was the only independent predictor for failing LVEF improvement [odds ratio 7.2 (95% confidence interval 2.2–23.4), P &lt; 0.001]. Echocardiographic ‘Super Response’ was observed in 55/64 (86%) patients without and 21/39 (54%) patients with LA fibrosis, respectively (P &lt; 0.001).

Conclusion

Presence and extent of LA fibrosis predict LVEF response in HF patients undergoing AF ablation. The assessment of LA fibrosis may impact prognostic stratification and clinical management in HF patients with AF.

P457Incidence of LA fibrosis and substrate-based AF ablation success rates in HF patients

Funding Acknowledgements

The author(s) received no specific funding for this work.

Background

In heart failure (HF) patients, sinus rhythm maintenance after catheter ablation for atrial fibrillation (AF) is mandatory to achieve better long-term outcome. Presence of left atrial (LA) fibrosis significantly attenuates ablation success rates. Incidence of LA fibrosis and the effect of an individualized substrate-based ablation concept on rhythm outcome in HF patients with AF is unclear.

Methods

This study investigated 103 patients (64 years, 69% men) with persistent AF (79%) and left ventricular (LV) dysfunction (EF 33% IQR [25; 38]) undergoing first time AF ablation. Identification of LA fibrosis and selection of ablation strategy were based on sinus rhythm voltage mapping. All patients received pulmonary vein isolation (PVI). LA fibrosis ablation was individualized by (i) homogenization of small areas, (ii) linear lesions connecting fibrosis and anatomical obstacles and (iii) linear lesions isolating large fibrotic areas. Rhythm outcome was measured by continuous device monitoring (AF detection ≥ 6 min) or Holter-ECG. A total post-procedural AF burden &lt; 0.1% was defined as successful rhythm control.

Results

LA fibrosis in the overall cohort, in paroxysmal and persistent AF patients was detected in 39/103 (38%), 6/22 (27%) and 33/81 (41%), respectively. After 11 ± 5 months and 1.2 procedures/patient, freedom from AF recurrence was similar between patients with and without LA fibrosis (33/39 (84%) vs. 54/64 (84%); p = 0.485). With continuous monitoring, 73/87 (84%) patients recorded a total AF burden &lt; 0.1%. There was no significant difference in AF burden outcome between patients with and without LA fibrosis (3.1% SD ±17.4 vs. 2.2% SD ±8.1; p = 0.4). No correlation between presence or extent of LA fibrosis and AF burden was found; p = 0.299.

Conclusion

A substantial number of HF patients with AF have no evidence of LA fibrosis. Among HF patients with LA fibrosis, individualized substrate-based AF ablation beyond PVI was able to achieve similar ablation success.

Electrophysiological findings during atrial fibrillation reablation: Extending from pulmonary vein reconnection to sequential bipolar voltage map information

BACKGROUND

Left atrial substrate modification targeting low voltage zones (LVZ) is an ablation strategy that-in addition to pulmonary vein (PV) isolation-tries to eliminate arrhythmogenic mechanisms harbored in such tissue. Electrophysiological findings at reablation include (a) PV reconnection, (b) reconnection over previous substrate ablation, and (c) de-novo LVZ.

OBJECTIVE

To study, prevalence and contribution of these arrhythmogenic electrophysiological entities in patients with atrial fibrillation (AF) recurrences.

METHODS

Consecutive patients with highly symptomatic AF undergoing index and reablation were included (n = 113). In all patients' PV reconnection, reconnection over previous substrate ablation and spontaneous de-novo LVZ were quantitatively assessed and integrated into an individual reablation strategy. Follow-up was based on continuous device monitoring.

RESULTS

At re-do procedure, 45 out of 113 (39.8%) patients showed PV reconnection as the only electrophysiological abnormality. Reconduction over previous lines was the only electrophysiological abnormality in 8 out of 113 (7.1%) patients. Spontaneous de-novo LVZ was the only electrophysiological abnormality in 12 out of 113 (10.6%) patients. Combined findings of PV reconnection, line reconduction, and/or spontaneous de-novo LVZ were seen in 40 out of 113 (35.4%) patients. No detectable electrophysiological abnormality was observed in 8 out of 113 (7.1%) patients. In univariate analysis, none of the tested electrophysiological characteristics independently predicted the outcome after re-do.

CONCLUSIONS

In patients undergoing reablation, we could show that reconduction over previous substrate ablation as well as the development of new low voltage areas are frequent findings besides classical PV reconnection-without a clear leading cause for recurrences. These findings impact reablation strategies as well as the strategic focus during index procedures.

P613Cardiac magnetic resonance imaging derived left ventricular mechanical function in patients with atrial fibrillation and left atrial low voltage zones

Background

The relation of left atrial low voltage zones (LVZ) to left ventricular function in patients undergoing pulmonary vein isolation (PVI) is not known.

Objective

To explore the relationship of left atrial low voltage zones (LVZ) on left ventricular function in patients with atrial fibrillation.

Methods

From June to Nov. 2018, 107 (mean age 67y, 70 men, 73 persistent AF) consecutive patients with symptomatic AF underwent a PVI with LVZ mapping. Before PVI the left ventricular ejection fraction (EF) and stroke volume (SV) were measured by cardiac magnetic resonance imaging (CMR). From feature-tracking of CMR-cine images left ventricular global, systolic and diastolic longitudinal strains (GLS), circumferential strains (GCS) and radial strains (GRS) were calculated.

Results

Of 59 patients CMR scanning in sinus rhythm was performed, LVZ were present in 24 patients.

LVEF was significantly lower in patients with left atrial LVZ (62±9% vs. 55±15%) (p=0,03). Left ventricular stroke volume was significantly decreased by the extent of LVZ (94±23 vs. 72±21ml), (p=0,03).

The left ventricular diastolic strains during ventricular filling (caused by atrial contraction) of GLS (r=−0,52), GCS (r=−0,65) and GRS (r=−0,65) were highly signifcantly correlated to the occurence and extent of LVZ (each p<0,001 respectively).

The only systolic ventricular strain was GLS, which decreased (r=−0,3, p=0,03) by the occurance of atrial low voltage.

Conclusion

The active, atrial part of diastolic left ventricular filling properties is impaired by the occurrence and extent of left atrial LVZ. In patients with left atrial LVZ the left ventricular stroke volume and ejection fraction is decreased already in sinus rhythm. It seems possible that atrial mechanical dysfunction and presence of atrial low voltage maybe predicted by LV diastolic strain analysis.

P605Correlation of left atrial phasic transport function and arrhythmogenic substrate in patients with atrial fibrillation: cardiac magnetic resonance feature tracking and bipolar voltage mapping

Background

Bipolar voltage mapping is a widely accepted approach to identify areas of arrhythmogenic substrate in patients presenting for atrial fibrillation (AF) ablation.

However, until now little is known about the correlation of left atrial (LA) bipolar voltage distribution and LA transport function.

Purpose

To study the impact of LA low voltage zones (LVZ) on LA transport function.

Methods

107 consecutive patients presenting for ablation of symptomatic AF (34 paroxysmal AF, 73 persistent AF) were prospectively enrolled. Each patient underwent cardiac magnetic resonance imaging (CMR) within 24 hours prior to the ablation procedure. 59 patients were in sinus rhythm (SR) and 48 in AF. LA phasic indexed volumes (LAVi) and ejection fractions were calculated using biplane area length formula. In addition LA phasic strains and strain rates were analyzed using dedicated software (Figure 1A & B).

LA bipolar voltage mapping was performed prior to beginning of ablation in sinus rhythm using a 3-dimensional mapping system and LVZ were defined as areas of bipolar voltage <0.5mV.

Results

LVZ were present in 47 patients (23 in SR). The area of LVZ was 14.6cm2 (5.3–34.0). For patients in AF at the time of CMR only elevated minimal and maximal LAVi (p=0.001 and p=0.002 respectively) but no LA functional parameter was predictive for the occurrence of LVZ. In contrast for patients in SR all LA phasic volumes (endsystolic, pre atrial contraction and enddiastolic LAVi) and LA function parameters (passive, active and total ejection fraction (EF), reservoir, conduit and booster pump strains and strain rates) were predictive for the occurrence of LVZ. After clustered and pooled multivariate logistic regression only impaired booster pump strain rate was still predictive for occurrence of LVZ (OR 0.974, 95% CI 0.950–0.998, p=0.036).

In addition Pearson correlation analysis revealed a strong link between LA booster pump functional parameters and cm2 expansion of LVZ areas: LA active EF, LA booster pump strain and SR (r=−0.42, p=0.044; r=−0.47, p=0.024; r=−0.65, p=0.001 [Figure 1C] respectively).

Conclusion

For patients in SR LA transport function is closely linked to the occurrence of LA LVZ and outperforms LA volumetric measurements for the prediction of LA LVZ.

Furthermore LA booster pump function parameters show robust correlation to the extension of LA LVZ.

Continuous monitoring after atrial fibrillation ablation: the LINQ AF study

Aims

To study device performance, arrhythmia recurrence characteristics, and methods of outcome assessment using a novel implantable cardiac monitor (ICM) in patients undergoing ablation for atrial fibrillation (AF).

Methods and results

In 419 consecutive patients undergoing first-time catheter ablation for symptomatic paroxysmal (n = 224) or persistent (n = 195) AF an ICM was injected at the end of the procedure. Telemedicine staff ensured full episode transmission coverage and manually evaluated all automatic arrhythmia episodes. Device detection metrics were calculated for ≥2, ≥6, and ≥10 min AF detection durations. Four methods of outcome assessment were studied: continuous recurrence analysis, discontinuous recurrence analysis, AF-burden analysis, and analysis of individual rhythm profiles. A total of 43 673 automatic AF episodes were transmitted over a follow-up of 15 ± 6 months. Episode-based positive predictive values changed significantly with longer AF detection durations (70.5% for ≥2 min, 81.8% for ≥6 min, and 85.9% for ≥10 min). Patients with exclusive short episode recurrences (≥2 to <6 min) were rare and their arrhythmia detection was clinically irrelevant. Different methods of outcome assessment showed a large variation (46–79%) in ablation success. Individual rhythm characteristics and subclinical AF added to this inconsistency. Analysis of AF-burden and individual rhythm profiles were least influenced and showed successful treatment in 60–70% of the patients.

Conclusion

We suggest AF detection duration >6 min and AF burden >0.1% as a standardized outcome definition for AF studies to come in the future.

Chicago community-based asthma intervention trial: feasibility of delivering peer education in an inner-city population

The most effective means of educating children with asthma and their families has not been clearly demonstrated in previous studies. Peer education is uniquely suited to the complex problems encountered in underserved populations. The purpose of this study was to show the feasibility of delivering a peer education program for children with asthma and the effect of the program on indoor allergen levels in an inner-city population in Chicago. Overall, the program was well received. Baseline allergen levels were consistent with some previous studies in showing low levels of mite allergens and high levels of cockroach allergens, with 79.6% of samples having levels > 8 U/g. A total of 28.2% of samples had cat allergen levels > 2 microg/g, although only 9.7% of homes had cats, confirming previous reports that cat allergen is ubiquitous. Mold levels were seasonal, with the highest levels in the summer. Results from this study suggest that intervention programs should focus more on elimination of cockroaches than was previously appreciated, while minimizing the use of pesticides, and on identification of the sources of cat allergen. Structural and psychosocial issues in homes need to be addressed in future studies. This study has demonstrated the feasibility of delivering peer education in a inner-city population and highlighted the need for comprehensive intervention strategies addressing complex issues facing underserved neighborhoods.

Relationships of race and socioeconomic status with prevalence, severity, and symptoms of asthma in Chicago school children

BACKGROUND

Asthma mortality rates in Chicago are among the highest in the United States, with substantially greater rates in poor and minority populations. How much of the differential can be attributed to differences in prevalence versus severity or access to care has not been determined.

OBJECTIVE

To examine rates of asthma prevalence, severity, and symptoms and to explore the relationships of these rates to race and socioeconomic status in a random sample of Chicago school children.

METHODS

Self-administered survey.

RESULTS

Overall, rates of asthma were higher than previously reported, with 16% of students in the stratified cluster random sample of 3,670 children in the 7th and 8th grades having had asthma. Prevalence rates were significantly higher in schools with >98% African Americans than in other schools, with the highest prevalence rates seen in African American schools in low income neighborhoods. Rates were associated with the percent of African American children in the school and with median income of the school's census tract. Relationships were most consistent with indices of more severe disease.

CONCLUSIONS

Asthma prevalence is higher than previously noted, with rates greatest in minority and low income populations. Differences are more striking for measures of severity than for symptoms of wheezing, but are far less than previously reported differences in mortality, suggesting that additional factors, such as differential access to continuous health care, may be affecting high death rates from asthma in Chicago.