DECAAF II - Efficacy of DE-MRI-Guided Ablation vs. Conventional Catheter Ablation of Atrial Fibrillation


Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people in the US and around the world. AF is caused by an electrical problem within the upper chambers of the heart which causes the heart to beat irregularly. Over the last 15 years, the catheter-based AF ablation procedure has been widely adopted. This procedure removes abnormal tissue that may be causing the irregular rhythm. Unfortunately, ablation results in patients with "persistent" AF have been had low success rates in suppressing arrhythmias.

Results from the first DECAAF study, led by Dr. Nassir Marrouche at the University of Utah, showed that one of the most important predictors of catheter ablation outcome was the degree of ablation of the abnormal or 'fibrotic' tissue (fibrosis); the more fibrotic tissue that was treated with ablation, the better the outcome. These results were the motivation for the DECAAF II study.

DECAAF II Study Summary

DECAAF II is a clinical trial that will compare two ablation procedures: the conventional pulmonary vein isolation (PVI) ablation, and PVI + fibrosis-guided ablation. In this study, adult patients who consent to participate will be randomized (assigned by a process to flipping a coin) to one of the two ablation procedures. We hypothesize that patients receiving fibrosis-guided ablation in addition to the conventional PVI ablation will have fewer atrial arrhythmia recurrences than those who receive PVI ablation alone.

Our patients will be followed using the FDA-approved mobile ECG Check application on a smart phone. Patients will be able to record ECG data daily on the device and the data will be to a central ECG review team. We predict that daily ECG follow-up will provide a better-defined endpoint than less frequent follow-up assessments as used in previous AF trials.

MRI-Guided Ablation

During this study, MRI images will be used to look at changes in cardiac tissues to better identify and treat abnormal tissue in the upper chambers of the heart. This may improve the success rates of AF procedures.


Each person that chooses to participate in the study will capture ECG (heart rhythm) data using the ECG Check device and their personal smart phone. The ECG tracing will be transmitted automatically to a central location with the capability to read, interpret and store ECG tracings. Patients will be instructed to record their ECG daily, and this will help determine if a patient if atrial fibrillation has recurred.

Study Details

About 888 adults will be enrolled in this study over 2 years. Enrollment in the DECAAF II Trials is expected to begin Spring 2016.


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