Left Atrial Remodeling and Response to Valsartan in the Prevention of Recurrent Atrial Fibrillation

BACKGROUND: Left atrial (LA) dilation precedes or appears early after the onset of atrial fibrillation (AF) and factors in perpetuating the arrhythmia. Angiotensin receptor blockers were proposed for reversing LA remodeling. We evaluated the effect of valsartan on LA remodeling in patients with a recent episode of AF and the effect of LA size on AF recurrence (AFr). METHODS AND RESULTS: LA and left ventricular (LV) echocardiographic variables were measured at baseline and 6 and 12 months in 340 patients from GISSI-AF, a trial testing valsartan prevention of AFr. Reversal of remodeling was considered as a decrease in LA size over 12 months. Changes in patients with and without recurrence and the relationship to duration of AFr were analyzed. Patients were 68.4±8.8 years old, with history of hypertension (85.3%) and cardioversion in the previous 2 weeks (87.4%) or ≥2 AFr in the previous 6 months (40.4%). Baseline LA maximal volume (LAVmax) was severely increased (>40 mL/m(2)); LV dimensions and function were relatively normal. Over 12 months, 54.4% of patients had AFr. LAVmax was unchanged by rhythm, time, or randomized treatment. Higher baseline LAVmax and lower LA emptying fraction were linearly related to increasing AFr duration during follow-up. CONCLUSIONS: GISSI-AF patients in sinus rhythm and history of AF showed severely increased LAVmax with mostly normal LV volume, mass, and systolic and diastolic function. Valsartan for 1 year did not reverse LA remodeling or prevent AFr. Half of the patients without AFr had severe LA dilation; therefore, mechanisms other than structural remodeling triggered recurrence.