Table 1. Classification Utah, which divides patients into four groups according to degree of fibrosis.

Utah grade	LA wall DCE	Successful ablation (%)	AF recurrence (%)
Utah I	≤ 5%	100%	0
Utah II	5% to ≤ 20%	81.8%	28%
Utah III	20% to ≤ 35%	62.5%	35%
Utah IV	> 35%	0	56%

AF: atrial fibrillation; DCE: delayed contrast enhancement; LA: left atrial.