Left atrial functional remodeling assessed by echocardiography in patients undergoing ablation for atrial fibrillation: correlation with the presence of fibrosis and invasive atrial pressure

Funding Acknowledgements

Type of funding sources: None.

Background

Radiofrequency catheter ablation of pulmonary veins has become a common procedure for treatment of atrial fibrillation (AF). Nevertheless, the procedure is characterized by an extremely variable success rate, which reflects a great heterogeneity of factors implicated in AF recurrence and AF burden.

Purpose

We focused on the role of left atrium (LA) in patients with paroxysmal and persistent AF who underwent catheter pulmonary veins ablation procedure. In particular we paid attention to three factors: echocardiographic evaluation of LA function, LA scar evaluated by electroanatomic mapping and LA pressures (LAP) during ablation procedure. The aim of the study was to investigate the correlation between echocardiographic parameters indicating atrial dysfunction (LA volume indexed, E/E’, LAA contraction velocity, LA stiffness and LA longitudinal strain during reservoir phase (LASr)) and intraprocedural parameters (such as LAPpeak and the amount of fibrosis).

Methods

 The study included 25 patients; mean age was 63 ± 8 years; nineteen patients (76%) had paroxysmal AF, eighteen patients (72%) were in sinus rhythm at the time of ablation. The population was divided into two subgroups according to the amount of fibrosis evaluated by electroanatomic mapping: patients with fibrosis ≥ 5% of the total LA volume were considered as having an atrial scar. All patients underwent a comprehensive transthoracic echocardiography and a transesophageal echocardiography before the ablation procedure. Intraprocedural data regarding LAPpeak and electroanatomic mapping were collected. Measurements were acquired during both sinus rhythm (SR) and AF.

Results

Patients with atrial scar had similar LA volume compared to patients without scar (44  ml vs 37.4 ml, p = 0.108) , but presented a trend towards higher LAPpeak (24.3 mmHg vs 15.9 mmHg, p = 0.053) and had higher E/E’ (11 vs 7, p = 0.037) and consequently increased LA stiffness (0.72 vs 0.23, p= 0.006). Still, they had lower LASr  (16.6% vs 33.2%, p = 0.013) and tended to have reduced LAA contraction velocity (0.4 m/sec vs 0.7 m/sec, p= 0.005).

Conclusions

The present findings suggest that functional remodeling of the LA, more than morphological changes, are correlated with the presence of atrial fibrosis and elevated atrial pressure detected during ablation procedures. These parameters may represent potential criteria to guide patients’ selection for ablation procedure and deserve dedicated studies to be confirmed. Abstract Figure.

ICM Implantation and Remote Follow-Up Management by Trained Nurses in Italian Hospitals: Current Practice and Nurse Feedback

AIMS

This project aimed to evaluate current practices of trained nurses performing implantable cardiac monitor (ICM) implantations and remote follow-ups in Italy, assessing hospital protocols and nurses' perceptions.

METHODS

An anonymous survey was conducted among 163 trained nurses across 75 Italian hospitals, focusing on their ICM implantation and remote monitoring practices. Data collected included hospital characteristics and protocols, barriers to implementation, and nurses' feedback on their experiences.

RESULTS

Of the 112 respondents (69% response rate), 60% reported that nurses in their hospitals are authorized to perform ICM implantations, and 70% said that they can manage all remote monitoring tasks. Thirty-three (29%) nurses manage all aspects of ICM patient care, including implantation, programming, enrollment in remote monitoring, training, data review, and follow-up. Fifty-five percent of nurses perform a part of ICM implants outside the EP/Cath lab, and for 31%, this is the primary location. 84% of implanter nurses achieved autonomy after < 10 supervised implants. More than 90% of implanter nurses consider ICM implantation rewarding and 96% find it safe and easy with the provided kit. However, only 33% and 17% of nurses had written protocols at their hospital, to guide ICM implantation and remote monitoring, respectively.

CONCLUSIONS

Nurse-led ICM implantation and remote follow-up are becoming established practices in Italy, with many nurses operating independently. Despite this progress, the absence of standard operating procedures limits the widespread adoption of these practices. Clear national and international protocols are essential to enhance nurse training, ensure safe practices, and ultimately improve patient care in ICM management.

Personalized computational electro-mechanics simulations to optimize cardiac resynchronization therapy

In this study, we present a computational framework designed to evaluate virtual scenarios of cardiac resynchronization therapy (CRT) and compare their effectiveness based on relevant clinical biomarkers. Our approach involves electro-mechanical numerical simulations personalized, for patients with left bundle branch block, by means of a calibration obtained using data from Electro-Anatomical Mapping System (EAMS) measures acquired by cardiologists during the CRT procedure, as well as ventricular pressures and volumes, both obtained pre-implantation. We validate the calibration by using EAMS data coming from right pacing conditions. Three patients with fibrosis and three without are considered to explore various conditions. Our virtual scenarios consist of personalized numerical experiments, incorporating different positions of the left electrode along reconstructed epicardial veins; different locations of the right electrode; different ventriculo-ventricular delays. The aim is to offer a comprehensive tool capable of optimizing CRT efficiency for individual patients. We provide preliminary answers on optimal electrode placement and delay, by computing some relevant biomarkers such as d P / d t max , ejection fraction, stroke work. From our numerical experiments, we found that the latest activated segment during sinus rhythm is an effective choice for the non-fibrotic cases for the location of the left electrode. Also, our results showed that the activation of the right electrode before the left one seems to improve the CRT performance for the non-fibrotic cases. Last, we found that the CRT performance seems to improve by positioning the right electrode halfway between the base and the apex. This work is on the line of computational works for the study of CRT and introduces new features in the field, such as the presence of the epicardial veins and the movement of the right electrode. All these studies from the different research groups can in future synergistically flow together in the development of a tool which clinicians could use during the procedure to have quantitative information about the patient's propagation in different scenarios.

[How to identify non-responders to cardiac resynchronization therapy]

Cardiac resynchronization therapy (CRT) has been shown to improve survival, morbidity, symptoms, quality of life and exercise capacity, and to promote a beneficial reverse remodeling of the left ventricle in patients with heart failure, dilated hypokinetic left ventricle and wide QRS. The totality of evidence supports the use of CRT also in patients with mild symptoms (NYHA class II). However, the wider diffusion of CRT is determining a growing clinical and economic impact on national health systems. In clinical practice, in spite of "all-or-none" response, variable degrees of therapy response are commonly observed, but several evidence gaps remain to be addressed. According to recent guidelines for CRT implantation, a multiparametric combination of predictive factors emerging from the analysis of clinical trials, observational studies and registries, represents a useful tool for patient selection.

Endocavitary electrophysiological study by percutaneous antecubital vein and without X-ray for risk stratification of asymptomatic ventricular pre-excitation in young athletes

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Evaluation of AP is usually performed by transesophageal and intracardiac studies.

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In young athletes with AVP, our standard of care is to perform ESnoXR.

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ESnoXR may considered a less invasive alternative for risk stratification of AP.

Athletes with asymptomatic ventricular pre-excitation (VP) should undergo electrophysiological study for risk stratification. We aimed to evaluate the feasibility, efficacy, safety and tolerability of an electrophysiological study using a percutaneous antecubital vein access and without the use of X-ray (ESnoXr). Methods: We collected data from all young athletes < 18 year-old with AVP, who underwent ESnoXr from January 2000 to September 2020 for evaluation of accessory pathway refractoriness and arrhythmia inducibility using an antecubital percutaneous venous access. Endocavitary signals were used to advance the catheter in the right atrium and ventricle. Results: We included 63 consecutive young athletes (mean age 14.6 ± 1.9 years, 46% male). Feasibility of the ESnoXr technique was 87% while in 13% fluoroscopy and/or a femoral approach were needed. Specifically, fluoroscopy was used in 7 cases to position the catheter inside the heart cavities with an average exposure of 43 ± 38 s while in 2 femoral venous access was needed. The mean procedural time was 35 ± 11 min. The exam was diagnostic in all patients, there were no procedural complications and tolerability was excellent. 53% of the patients had an accessory pathway with high refractoriness and no inducible atrio-ventricular reentry tachycardia: this subgroup was considered eligible to competitive sports and no event was observed during long-term follow-up (13.6 ± 5.2 years) without drug use. The others underwent catheter ablation. Conclusion. ESnoXr has been shown to be a feasible, effective, safe and well-tolerated procedure for the assessment of arrhythmic risk in a population of young athletes with asymptomatic VP.

Daily and automatic remote monitoring of implantable cardiac monitors: A descriptive analysis of transmitted episodes

BACKGROUND

Remote Monitoring (RM) is recognized for its ability to enhance the clinical management of patients with implantable cardiac monitor (ICM). This study aims to provide a comprehensive description of the arrhythmic episodes transmitted by a daily and automatic RM system from a cohort of ICM patients.

METHODS

The study retrospectively analyzed daily transmissions from consecutive patients who had been implanted with a long-sensing vector ICM (BIOMONITOR III/IIIm) at four sites. All transmitted arrhythmic recordings were evaluated to determine whether they were true positive episodes or false positives (FP).

RESULTS

A total of 14,136 episodes were transmitted from 119 patients (74.8% male, median age 62 years old) during a median follow-up of 371 days. The rate of arrhythmic episodes was 14.2 per patient-year (interquartile range: 1.8-126), with 97 patients (81.5%) experiencing at least one ICM activation. Fifty-five percent of episodes were identified as FP, and 67 patients (56.3%) had at least one inappropriate activation. The FP rate was 1.4 per patient-year (0-40). The best per-episode predictive positive values were observed for bradycardia and atrial fibrillation (0.595 and 0.553, respectively). Notably, the implementation of an algorithm designed to minimize false detections significantly reduced the prevalence of atrial fibrillation FP episodes (17.6% vs. 43.5%, p = 0.008).

CONCLUSION

Daily and automatic RM appears to be a reliable tool for the comprehensive remote management of ICM patients. However, the number of arrhythmic episodes requiring review is high, and further improvements are needed to reduce FP and facilitate accurate interpretation of transmissions.

Incidental and anticipated arrhythmic diagnoses in patients with an implantable cardiac monitor

AIMS

In this study, we investigated a cohort of unselected patients with various indications for an implantable cardiac monitor (ICM). Our main objectives were to determine the incidence of arrhythmic diagnoses, both anticipated and incidental in relation to the ICM indication, and to assess their clinical relevance.

METHODS

We examined remote monitoring transmissions from patients with an ICM at four Italian sites to identify occurrences of cardiac arrhythmias. Concurrently, we collected data on medical actions taken in response to arrhythmic findings.

RESULTS

The study included 119 patients, with a median follow-up period of 371 days. ICM indications were syncope/presyncope (46.2%), atrial fibrillation management (31.1%), and cryptogenic stroke (22.7%). In the atrial fibrillation management group, atrial fibrillation was the most common finding, with an incidence of 36% [95% confidence interval (CI) 22-55%] at 18 months. Rates of atrial fibrillation were not significantly different between patients with cryptogenic stroke and syncope/presyncope [17% (95% CI 7-40%) vs. 8% (95% CI 3-19%), P  = 0.229].For patients with cryptogenic stroke, the incidence of asystole and bradyarrhythmias at 18 months was 23% (95% CI 11-45%) and 42% (95% CI 24-65%), respectively, similar to estimates obtained for patients implanted for syncope/presyncope ( P  = 0.277 vs. P  = 0.836).Overall, 30 patients (25.2%) required medical intervention following ICM-detected arrhythmias, predominantly involving atrial fibrillation ablation (10.9%) and medication therapy changes (10.1%).

CONCLUSION

In a real-life population with heterogeneous insertion indications, approximately 25% of patients received ICM-guided medical interventions within a short timeframe, including treatments for incidental findings. Common incidental arrhythmic diagnoses were bradyarrhythmias in patients with cryptogenic stroke and atrial fibrillation in patients with unexplained syncope.

Prediction of mortality in patients with implantable defibrillator using CHADS2 score: data from a prospective observational investigation

BACKGROUND

CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, previous stroke/TIA) score has been validated as a risk stratification score to predict stroke in patients with atrial fibrillation (AF). The objective of this analysis was to assess whether patient risk factors, in particular CHADS2 score, identified patients at risk of mortality.

METHODS

821 patients with an implantable cardioverter defibrillator were prospectively followed-up in 11 cardiology centers. Patients were grouped in 3 groups according to pre-specified risk classes: low (CHADS2 = 0), moderate (CHADS2 = 1, 2), and high (CHADS2 = 3-6). Information on clinical status and events, were collected during scheduled and unscheduled follow-up visits. Deaths were retrieved from medical records, or through the Regional Office of Vital Statistics.

RESULTS

Over a mean follow-up of 44±26 months, 135 deaths occurred in the overall population: 6 (7.7%) in the low-risk population, 69 (13.8%) in moderate-risk patients and 60 (24.6%) in high-risk patients. Kaplan-Meier estimated of patient survival were significantly different in 3 patients groups (93.0%, 90.1%, 78.5% in low, moderate and high risk patients respectively, at 4 years P<0.001). A sub-analysis on patients without history of AF showed similar results. Multivariate regression analysis adjusted for baseline characteristics confirmed the high risk status (HR 1.88, 95% CI 1.27-2.80; P = 0.002) as an independent predictor of mortality adjusted for the baseline characteristics.

CONCLUSIONS

In our multicenter research, the long-term mortality was higher in patients with high CHADS2 score than in those with lower risk score regardless the presence of history of AF. CHADS2 score could be considered a toll to predict all causes mortality.

Effect of rate-adaptive atrial support compared to VDD pacing in cardiac resynchronization therapy recipients: A randomized cross-over study

BACKGROUND

Cardiac resynchronization therapy (CRT) is a cornerstone treatment for heart failure, yet the optimal pacing mode remains uncertain. This study investigates the impact of DDDR (rate-adaptive atrial support) versus VDD pacing modes on functional capacity and echocardiographic outcomes in patients with CRT-defibrillators.

METHODS

In a multicenter, double-blind, crossover trial, 26 sinus rhythm patients undergoing CRT-defibrillator implantation were randomized to DDDR at 60 beats-per-minute or VDD at 30 beats-per-minute. Each pacing mode was maintained for 6 months (period 1), followed by crossover to the alternate programming for additional 6 months (period 2). Distance covered in the 6-minute walk test (6MWT) and echocardiographic parameters were evaluated at baseline and after each period.

RESULTS

The proportion of CRT responders was 73% at 6 months and 79% at 12 months. DDDR pacing yielded a median atrial pacing percentage of 55% (interquartile range, 48%-71%). No significant difference was found between DDDR and VDD modes in 6MWT distance (448 m [369-538] vs. 428 m [360-535], P = .71). The sequence of pacing modes was also not significant (P = .17), while the study period (P = .03) and the distance covered at baseline (P < .01) were positively correlated with the distance walked at follow-up. Echocardiographic parameters, including left ventricular ejection fraction and ventricular volumes, showed no significant differences between the pacing modes.

CONCLUSIONS

In this cohort, rate-adaptive atrial support did not offer any advantage over VDD pacing in terms of functional capacity or echocardiographic response. The findings support the recommendation to maximize intrinsic sinus rhythm sensing in CRT devices.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT06592690.