Certain embodiments of the invention provide methods of assessing a patient's risk for atrial fibrillation (AF) recurrence after receiving treatment with an AF treatment modality, that include determining, from left atrium (LA) tissue image data of a patient, a level of a parameter that is positively proportional to an amount of unhealthy tissue in a wall of the LA of the patient; and outputting, to an output device, an indicator of a comparison between (i) the determined level and (ii) a first threshold level of the parameter, the first threshold level derived from LA tissue image data of at least one other patient, who experienced an AF recurrence after treatment with the AF treatment modality. In certain embodiments, levels of the parameter equal to or greater than the first threshold level are indicative of a significant risk of AF recurrence after treatment with the AF treatment modality.