Anatomical Predictors of Optimal Cryoballoon Size Selection: A Prospective Comparison of 28 mm Versus 31 mm Size‐Adjustable Balloon Modes

Figures

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  FIGURE 1. Comparison of complete occlusion (Grade IV) rates between 28 and 31 mm balloon modes across all four pulmonary veins. The 31 mm mode achieved significantly higher occlusion rates for superior PVs (LSPV: 97.3% vs. 88.7%, p = 0.0002; RSPV: 93.3% vs. 71.3%, p < 0.0001) but not for inferior PVs (LIPV: P = 1.000; RIPV: P = 0.070). p values calculated using McNemar's exact test for paired proportions. Error bars represent 95% confidence intervals. LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein.

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  FIGURE 2. Receiver operating characteristic (ROC) curves for pulmonary vein diameter and ovality index as predictors of incomplete occlusion (Non‐OG4) with 28 mm balloon mode. (A) Left superior pulmonary vein diameter: AUC 0.76, suggested threshold > 20 mm for preferring 31 mm mode (sensitivity 88%, specificity 63%). (B) Left superior pulmonary vein ovality index: AUC 0.65, limited discriminative value. (C) Right superior pulmonary vein diameter: AUC 0.78, suggested threshold > 22 mm for preferring 31 mm mode (sensitivity 72%, specificity 73%). (D) Right superior pulmonary vein ovality index: AUC 0.58, poor discriminative value. Note: These exploratory findings require validation due to small Non‐OG4 sample sizes (LSPV: N = 4, RSPV: N = 10). AUC, area under the curve.

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  FIGURE 3. Exploratory clinical algorithm for balloon size selection based on pre‐procedural CT anatomical assessment. The algorithm is founded on the key insight that larger PVs are harder to occlude (GEE analysis: OR 0.59 per SD increase in diameter). Suggested thresholds: LSPV > 20 mm, RSPV > 22 mm for preferring 31 mm mode. For inferior PVs, 28 mm is recommended as default given no significant benefit from 31 mm (LIPV p = 1.000; RIPV p = 0.070). This exploratory, hypothesis‐generating framework requires prospective validation before clinical implementation. The algorithm incorporates left atrial diameter as a safety consideration. CT, computed tomography; LA, left atrium; LSPV, left superior pulmonary vein; RSPV, right superior pulmonary vein; PV, pulmonary vein.