Is contrast used during pulmonary vein isolation for atrial fibrillation (AF) ablation?

From the Guidelines

Yes, contrast is used during pulmonary vein isolation for atrial fibrillation (AF) ablation, as evidenced by the recent study published in the Journal of the American College of Radiology in 2024 1. The use of contrast during this procedure is crucial for visualizing the pulmonary vein anatomy and their ostia, which helps guide catheter placement and ensures proper lesion delivery around the pulmonary veins.

• The standard approach involves injecting contrast into each pulmonary vein or directly into the left atrium to delineate the pulmonary vein-left atrial junction.
• Contrast use helps reduce the risk of complications by identifying anatomical variations and preventing ablation too deep within the veins, which could lead to pulmonary vein stenosis.
• According to the study, CTA of the chest can allow for assessment of the left atrium, LAA, and pulmonary venous anatomy as an alternative to CT heart, and the use of non–ECG-gated CTA can decrease the dose of contrast medium used without significant difference in the visual quality of the images, catheter ablation parameters, and AF recurrence rate 1.
• Additionally, the study found that delayed contrast imaging can be used for thrombus detection in patients with AF, with a sensitivity and NPV for LAA thrombus detection of 100% and a specificity of 98% when compared with intraprocedural intracardiac echocardiography and preprocedural TEE 1.
• In modern practice, contrast venography is often complemented by other imaging modalities like intracardiac echocardiography or pre-procedural CT/MRI integration with electroanatomic mapping systems, allowing for reduced contrast volume while maintaining procedural efficacy.
• Patients with renal impairment may require contrast minimization strategies or alternative imaging approaches, highlighting the need for individualized approaches to contrast use during AF ablation procedures.

From the Research

Use of Contrast in Pulmonary Vein Isolation for Atrial Fibrillation Ablation

• Contrast is used during pulmonary vein isolation for atrial fibrillation (AF) ablation to assess pulmonary vein (PV) occlusion, as seen in studies 2, 3.
• The use of contrast injection within the PV lumen is a conventional method to assess complete occlusion during cryoballoon ablation (CBA) 2.
• However, alternative techniques such as intracardiac saline echocontrastography 2 and direct pressure monitoring 3 have been developed to reduce the use of contrast and fluoroscopy time.
• These alternative techniques have been shown to be effective in predicting PV occlusion and reducing procedural time, radiological exposure, and iodinated contrast use 2, 3.

Alternative Techniques for Assessing PV Occlusion

• Intracardiac saline echocontrastography has been shown to be a useful technique in guiding CBA, with a high level of agreement with angiographic diagnosis of occlusion 2.
• Direct pressure monitoring has been shown to be a novel and accurate method for assessing PV occlusion, with a high success rate of PV isolation 3.
• These alternative techniques may reduce the reliance on contrast injection, but contrast is still used in some cases to confirm PV occlusion 3.

Reduction of Contrast Use

• The use of alternative techniques such as intracardiac saline echocontrastography and direct pressure monitoring can reduce the amount of contrast used during PV isolation procedures 2, 3.
• A meta-analysis of studies comparing zero or low fluoroscopy approaches to conventional fluoroscopy approaches for AF ablation found that low fluoroscopy approaches were associated with shorter procedure duration, fluoroscopy time, and dose area product 4.