CAMERA-MRI score to predict left ventricular ejection fraction normalization post-ablation for primary atrial fibrillation-mediated cardiomyopathy: A pooled analysis of two randomized clinical trials.

BACKGROUND

Primary atrial fibrillation (AF)-mediated cardiomyopathy is a retrospective diagnosis in which left ventricular ejection fraction (LVEF) normalizes following catheter ablation. Identifying prospectively which patients will achieve LVEF normalization remains challenging.

OBJECTIVE

To determine predictors of LVEF normalization in patients with AF-mediated cardiomyopathy following catheter ablation.

METHODS

This was a pooled analysis of the CAMERA-MRI and CAMERA-MRI II multicenter randomized trials, which included baseline and serial cardiac magnetic resonance. This sub-study included all patients who underwent catheter ablation. LVEF normalization predictors were assessed using univariable and multivariable logistic regression. Continuous variables were dichotomized to develop a practical score, internally validated through bootstrap resampling (200 iterations) and 5-fold cross-validation.

RESULTS

113 patients (mean age, 60.6 ± 11.1 years; 13.3% female; 90.3% persistent AF; baseline LVEF, 31.0% ± 8.7%) were included, and 70 (63.7%) achieved LVEF normalization on serial cardiac magnetic resonance. On multivariable analysis, there were 3 independent predictors: normal indexed LV end-diastolic volume (odds ratio [OR], 3.20; 95% confidence interval [CI], 1.20-8.56; P = .021), absence of alternate etiology (OR, 4.31; 95% CI, 1.14-16.39; P = .023), and absence of late gadolinium enhancement (OR, 2.53; 95% CI, 1.01-6.39; P = .049), with an area under the curve of 0.788 (95% CI, 0.703-0.873). Normalization likelihood by score was 12% (0/3), 38% (1/3), 67% (2/3), and 88% (3/3).

CONCLUSION

Absence of late gadolinium enhancement, normal LV volumes, and absence of an alternative etiology identified that the AF-induced cardiomyopathy phenotype is most likely to achieve LVEF normalization following catheter ablation.