Addition of Atrial Myopathy to HATCH Score for Predicting New-Onset Atrial Fibrillation After Ablation of Atrial Flutter

Background: The available risk prediction models are inadequate to identify a true low-risk patient for developing new-onset atrial fibrillation (AF) after typical atrial flutter (AFL) ablation. We aimed to determine whether adding markers of atrial myopathy to HATCH score (hypertension, age ≥75 years, transient ischemic attack/stroke, chronic obstructive pulmonary disease, and heart failure) can improve prediction of new-onset AF after ablation of typical AFL. Methods: The study included 208 consecutive patients who underwent successful ablation of typical AFL at Minneapolis VA Medical Center and University of Minnesota Medical Center. Patients with history of AF prior to ablation were excluded. Results: Among the 208 patients, 76 (36.5%) developed new-onset AF post AFL ablation. Mean follow-up duration was 62 ± 31.8 months. HATCH score was not associated with new-onset AF. When adding atrial myopathy (presence of at least one of the following: PTFV₁ > 5000 µV*ms, interatrial block determined by biphasic inferior p wave with duration >120 ms, left atrium (LA) diameter ≥44 mm, or LA index ≥3 cm/m²) to HATCH score (HATCH-A₂), the combination was independently associated with new-onset AF. The AF incidence between HATCH-A₂ score of 0–1 and ≥2 were 6.7% and 40.5%, respectively (Odds ratio 9.04, 95% confidence interval: 2.05–39.81, p = 0.004). Particularly, when HATCH-A₂ score was 0, none of the patients developed AF. Conclusions: Adding atrial myopathy to HATCH score improved predictability and could be used to delineate a true low-risk patient of new-onset AF after typical AFL ablation.