Dark Regions of No-Reflow on Late Gadolinium Enhancement Magnetic Resonance Imaging Result in Scar Formation After Atrial Fibrillation Ablation
Why the study?
Catheter ablation success rates for atrial fibrillation vary partly due to limited acute information on injury extent and permanence, with early imaging predictors of scar remaining elusive.
Do nonenhancing (NE) regions on LGE MRI immediately post-ablation better predict permanent scar formation at 3 months compared to hyperenhancing (HE) regions in patients undergoing atrial fibrillation ablation?
Population
37 patients presenting for atrial fibrillation ablation
Comparison
Hyperenhancing vs nonenhancing acute left atrial wall injuries immediately post-ablation
Design
Prospective imaging cohort study
Follow-up
1-year follow-up
Key result
Nonenhancing (no-reflow) lesions on MRI immediately post-ablation were the primary source of permanent scar at 3 months (59.0% vs 30.6% for hyperenhancing tissue, p<0.001).
Authors
Discussion
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Member takes
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources linked on every quote.
“As advanced techniques for scar imaging become available, MRI will be an indispensable tool within the catheter lab itself.”
Overview
NE tissue may predominate in permanent scar; leaves open whether acute LGE patterns should guide ablation endpoints.
Key Points
- The study aims to evaluate the association between acute ablation injuries seen on late gadolinium enhancement MRI and permanent scar formation at three months post-ablation.
- Thirty-seven patients underwent high-resolution MRI pre-ablation, post-ablation, and at three months post-ablation using a 3-T scanner.
- Ablation injuries were categorized as hyperenhancing or nonenhancing, with comparisons made to scarring at three months post-ablation.
- Data on tissue types and scarring were analyzed for statistical significance.
- 59.0 ± 19% of scar at three months resulted from nonenhancing tissue, while 30.6 ± 15% came from hyperenhancing tissue.
- Changes in left atrial wall showed HE, NE, and normal tissue percentages were 37.7 ± 13%, 34.3 ± 14%, and 28.0 ± 11%, respectively; p = NS.
- Arrhythmia recurrence at 1-year follow-up correlated with 3-month wall enhancement degree (p = 0.02).
Study Design
Type
Observational (n=37)
Structured PICO
Do nonenhancing (NE) regions on LGE MRI immediately post-ablation better predict permanent scar formation at 3 months compared to hyperenhancing (HE) regions in patients undergoing atrial fibrillation ablation?
P
Population
37 patients presenting for atrial fibrillation ablation who underwent high-resolution MRI before, immediately post, and 3 months post-ablation.
E
Exposure
Radiofrequency ablation followed by high-resolution 3-T late gadolinium enhancement (LGE) MRI immediately post-ablation
C
Comparator
Comparison of hyperenhancing (HE) versus nonenhancing (NE) acute left atrial wall injuries on immediately post-ablation MRI
O
Outcome
Permanent scar formation at 3 months post-ablationsurrogate
Main Result
Absolute Event Rate: 59% vs 30.6%
p-value: p=<0.001
Nonenhancing 'no-reflow' lesions on LGE MRI immediately post-ablation are significantly better predictors of permanent scar formation at 3 months than hyperenhancing lesions.
Cite This Study
McGann et al. (2011) conducted an observational in Atrial fibrillation (n=37). Nonenhancing (NE) regions on late gadolinium enhancement MRI immediately post-ablation vs. Hyperenhancing (HE) and normal tissue was evaluated on Proportion of permanent scar at 3 months post-ablation resulting from specific tissue types (p=<0.001). Nonenhancing (no-reflow) lesions on MRI immediately post-ablation were the primary source of permanent scar at 3 months (59.0% vs 30.6% for hyperenhancing tissue, p<0.001).