Left Atrial Sphericity Index Predicts Early Recurrence of Atrial Fibrillation After Direct‐Current Cardioversion: An Echocardiographic Study

BACKGROUND Attempts to achieve rhythm control using direct‐current cardioversion ( DCC ) are common in those with persistent atrial fibrillation ( AF ). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atrial sphericity index ( LASI ) acquired by 2‐dimensional transthoracic echocardiography ( TTE ) could be used as a predictor of AF recurrence after successful DCC . Hypothesis A baselline LASI assessed by 2D TTE can predict AF recurrence after successful DCC in patients with persistent AF. Methods A total of 124 consecutive patients with persistent AF lasting <120 days underwent successful DCC . Other than β‐blockers, no other antiarrhythmic treatment was administered. Prior to DCC , all patients underwent thorough TTE , and LASI was calculated as the fraction of the left atrial width/length of the largest possible left atrial volume in a 4‐chamber view. The primary outcome was a TTE ‐estimated baseline LASI as a predictor of AF recurrence after successful DCC for persistent AF . Results Anatomically, a more spherical shape of the left atrium ( LASI >0.9) proved to be a strong and independent predictor of AF recurrence, with an odds ratio between 4.1 (95% confidence interval: 1.6‐11.9, P = 0.005) and 7.6 (95% confidence interval: 3.3‐19.7; P = 7.2 × 10 −6 ). The receiver operating characteristic curve indicated good power for distinguishing between recurring and nonrecurring AF , and we chose a cutoff of 0.9 because high specificity was a priority for clinical reasons. Conclusions In conclusion, baseline LASI >0.9 was associated with significantly greater AF recurrence throughout the 12‐month follow‐up period.