Ablation therapy in atrial fibrillation

Multiomics analysis of canine myocardium after circumferential pulmonary vein ablation: Effect of neuropeptide Y on long-term reinduction of atrial fibrillation

Catheter ablation (CA) is an essential method for the interventional treatment of atrial fibrillation (AF), and it is very important to reduce long-term recurrence after CA. The mechanism of recurrence after CA is still unclear. We established a long-term model of beagle canines after circumferential pulmonary vein ablation (CPVA). The transcriptome and proteome were obtained using high-throughput sequencing and TMT-tagged LC-MS/LC analysis, respectively. Differentially expressed genes and proteins were screened and enriched, and the effect of fibrosis was found and verified in tissues. A downregulated protein, neuropeptide Y (NPY), was selected for validation and the results suggest that NPY may play a role in the long-term reinduction of AF after CPVA. Then, the molecular mechanism of NPY was further investigated. The results showed that the atrial effective refractory period (AERP) was shortened and fibrosis was increased after CPVA. Atrial myocyte apoptosis was alleviated by NPY intervention, and Akt activation was inhibited in cardiac fibroblasts. These results suggest that long-term suppression of NPY after CPVA may lead to induction of AF through promoting cardiomyocyte apoptosis and activating the Akt pathway in cardiac fibroblasts, which may make AF more likely to reinduce.

Current progress of computational modeling for guiding clinical atrial fibrillation ablation

Atrial fibrillation (AF) is one of the most common arrhythmias, associated with high morbidity, mortality, and healthcare costs, and it places a significant burden on both individuals and society. Anti-arrhythmic drugs are the most commonly used strategy for treating AF. However, drug therapy faces challenges because of its limited efficacy and potential side effects. Catheter ablation is widely used as an alternative treatment for AF. Nevertheless, because the mechanism of AF is not fully understood, the recurrence rate after ablation remains high. In addition, the outcomes of ablation can vary significantly between medical institutions and patients, especially for persistent AF. Therefore, the issue of which ablation strategy is optimal is still far from settled. Computational modeling has the advantages of repeatable operation, low cost, freedom from risk, and complete control, and is a useful tool for not only predicting the results of different ablation strategies on the same model but also finding optimal personalized ablation targets for clinical reference and even guidance. This review summarizes three-dimensional computational modeling simulations of catheter ablation for AF, from the early-stage attempts such as Maze III or circumferential pulmonary vein isolation to the latest advances based on personalized substrate-guided ablation. Finally, we summarize current developments and challenges and provide our perspectives and suggestions for future directions.

Usefulness of Morphology-Voltage-P-wave duration (MVP) score as a predictor of atrial fibrillation recurrence after pulmonary vein isolation

Background

Atrial fibrillation (AF) is known to be the most common arrhythmia, and the successful rate of long‐term ablation can vary comparatively. Therefore, a clinical scoring system to predict rhythm outcome remains a critical unmet need. The electrocardiographic (ECG) risk score which is named Morphology‐Voltage‐P‐wave duration (MVP) score was reported to be useful for predicting new‐onset AF. The goal of the current study was to investigate whether the MVP score was a useful scheme in the prediction of rhythm outcome following pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF).

Methods

We retrospectively analyzed baseline characteristics, risk scores, and rates of AF recurrence 12 months postablation in the medical records of 207 consecutive patients with PAF undergoing PVI in General Hospital of Ningxia medical University from 2010 to 2018.

Results

Two hundred and seven patients (71 females, median age 58.7 years) with symptomatic PAF underwent PVI. From the cohort, 32.3% (67) had a recurrence of AF within 1 year of the PVI. The area of the MVP score under the curve in the receiver operating characteristics (ROC) analysis was 0.789 (95% CI 0.730–0.840, p < .001). A score cut‐off value of >3 showed the best predictive ability for AF recurrence within 1 year after PVI, with sensitivity (53.03%) and specificity (89.87%).

Conclusions

The results of our study suggest that the easy‐to‐measure ECG MVP score can be used to predict recurrence of PAF after PVI.