Prospective, multicenter validation of a clinical risk score for left atrial arrhythmogenic substrate based on voltage analysis: DR-FLASH score

BACKGROUND Left atrial (LA) low-voltage areas (LVAs) are frequently observed in patients with atrial fibrillation (AF) and may predict AF recurrence after catheter ablation. OBJECTIVE The aim of this study was to develop and validate a clinical tool to identify LVAs that are associated with AF recurrence after pulmonary vein isolation (PVI). METHODS In a cohort of 238 patients, voltage maps were created during LA procedures. LVAs were defined as areas With etectrogram amplitudes <0.5 mV. On the basis of regression analysis, predictors of LA substrate were identified. These parameters were used to establish a dedicated risk score (DR-FLASH score, based on diabetes mellitus, renal dysfunction, persistent form of AF, LA diameter >45 mm, age >65 years, female sex, and hypertension). This risk score was then prospectively validated in a multicenter cohort of 180 patients. The association of the score with tong-term recurrence of atrial arrhythmias after circumferential PVI was tested in a retrospective cohort of 484 patients. RESULTS The DR-FLASH score effectively identified LVA substrate (C statistic = 0.801, P < .001). In the prospective multicenter validation cohort, the predictive value of the DR-FLASH score was confirmed (C statistic = 0.767, P < .001). The probability for the presence of LA substrate increased by a factor of 2.2 (95% confidence interval [CI] 1.6-2.9, P < .001) with each point scored. Furthermore, the risk of AF recurrence after PVI increased by a factor of 1.3 (95% CI 1.1-1.5, P < .001) with every additional point and was almost 2 times higher in patients with a DR-FLASH score >3 (odds ratio 1.7, 950/0 CI 1.1-2.8, P = .026). CONCLUSION The DR-FLASH score may be useful to identify patients who may require extensive substrate modification instead of PVI alone.