Effect of Left Atrial Pulmonary Vein Angiography on Safety and Efficacy for High-Power, Short-Duration Pulmonary Vein Isolation in Patients with Atrial Fibrillation

Round 1

Reviewer 1 Report

Summary:

This is a well conceptualized and executed study evaluating the effect of performing pulmonary vein angiography during catheter ablation (High power short duration pulmonary vein isolation) in patients with atrial fibrillation. During this procedure, the pulmonary veins are identified and then isolated from the rest of the left atrium by creating scar tissue utilizing radiofrequency or other forms of energy in order to break the circuit of atrial fibrillation. In the current era of electrophysiology, high resolution mapping has become the norm in most centers for intra-procedure delineation of the pulmonary vein anatomy with angiography gradually losing favor. However, as the authors have pointed out, there has not been literature systematically evaluating this. The authors thereby have attempted to answer this question objectively with this study and have found that there is indeed no significant effect on safety or efficacy when pulmonary vein angiography is omitted. Additionally, omitting angiography significantly reduces the cumulative radiation dose to the patient and exposure to contrast agents. This paper provides objective evidence for the same and certainly contributes to current literature on the subject. Some additional comments (in no particular order of importance) that may improve the paper further are delineated below:

Major comments:

-          It may be of interest to mention how many of the patients had concomitant atrial flutter requiring additional substrate modification. Especially in each arm of the study.

-          While this is a retrospective study. Some additional clarity in terms of how the patients were chosen for each arm would be nice as the authors mention that performing pulmonary angiography was the standard at their center. Was there a reason angiography was not performed on a certain subset of patients?

-          In the methods, it would be useful to mention if and when anticoagulation was interrupted and whether any patients required bridging for any reason.

-          It would be useful to know if any pulmonary vein abnormalities were identified during the pre-procedure TEE?

-          The authors have mentioned some major and minor complications associated with the procedure, however it would be helpful to have a clear description of all major and minor complications being evaluated in the study to avoid any speculation. Also did any of the patients develop AKI? Especially those with CKD in the angiography arm. Granted the total contrast dose is minimal, but mentioning that will be helpful.

-          To readers not well-versed in electrophysiology, it may be inconspicuous as to why the angiography arm had lower procedure and fluoroscopy time. Expanding upon this will be very useful.

-          May be helpful to expand upon how WACA may capture additional pulmonary veins not identified by mapping alone.

-          The authors state that detection of pulmonary vein abnormalities by mapping alone may not be inferior to angiography. While this is indeed carefully worded, it cannot be overstated that this study by itself may not be adequately powered to generalize that statement.     

Minor comments:

-          Lines 208 – 210: Consider rephrasing “The time saving… could be compensated…” (Time saved… lost by more time needed for…)

-          Line 215: Consider rephrasing “… good image quality is bought by increased radiation.”

-          Line 238: Please mention the sample size of the cited study by Marom et al.

-          Some minor grammatical and language use errors are noted in the manuscript. 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors, I have studied with great interest the manuscript "Effect of Left Atrial Pulmonary Vein Angiography on Safety and Efficacy for High Power Short Duration Pulmonary Vein Isolation in Patients with Atrial Fibrillation".

According to population studies, atrial fibrillation and flutter occupy up to 35–45% in the structure of arrhythmias. The prevalence of AF increases with age, reaching 0.5% by the age of 40-50, and 5-15% by the age of 80. Electroanatomical mapping systems are considered the cornerstone of modern invasive cardiac electrophysiology, with the identification and modification of the underlying arrhythmogenic substrate becoming an ablation strategy that has improved the efficiency of AF ablation procedures.

The objectives of pulmonary vein angiography are to facilitate catheter manipulation, determine the size and localization of pulmonary vein orifices, and diagnose PV stenosis, especially in repeated procedures. An essential condition for the introduction of percutaneous transcatheter interventions in the treatment of cardiac arrhythmias and structural heart diseases is the development of the best strategies that can provide the most accurate anatomical information during procedures, reduce radiation exposure to the patient and reduce procedure time. This study is devoted to the study of these issues.

Results are clearly and well written. The authors convincingly showed that when using high-resolution mapping catheters in the High Power Short Duration (HPSD) technique, the effectiveness, efficiency, and complications of the ablation procedure are not associated with preoperative pulmonary venous angiography. The usefulness of using this protocol is emphasized by the reduction in the amount of contrast agent consumed and the reduction in radiation exposure (dose area product) to the patient, as well as the absence of clear differences in the incidence of periprocedural complications and endpoints.

At the same time, I consider it useful to provide information on whether "upstream therapy" therapy was used, aimed at the substrate of arrhythmia, and, if so, what were the results, given the lack of clear data to recommend with confidence its appointment after catheter ablation of AF in order to influence the processes of atrial remodeling.

But in general, I think that this is a very worthy work. I express my gratitude to the authors for their work and my great pleasure in reading their results.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

ALARA- As Low As Reasonably Achievable - this article perfectly sums up this principle. Why do PV angio when you don't have to? The authors have shown in their perfectly written article that PV angio can be safely omitted. The substantial number of patients and graphs make this article interesting to read, moreover, the findings can be safely implemented in the practic of the cath labs.

Author Response

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Author Response File: Author Response.docx