Abstract 14701: Greater Nighttime Blood Pressure Variability is Associated With Left Atrial Enlargement in Atrial Fibrillation Patients With Preserved Ejection Fraction

Introduction: The presence of left atrial (LA) enlargement is an independent risk factor for ischemic stroke in patients with atrial fibrillation (AF). Increased nighttime blood pressure (BP) variability is also known to be associated with stroke. However, little is known on the association between nighttime BP variability and LA enlargement. Therefore, this study was designed to clarify the influence of nighttime BP variability on LA enlargement in AF patients with preserved ejection fraction. Methods: The study population consisted of 98 consecutive AF patients (mean age, 64 ± 10 years) with preserved ejection fraction (EF ≥ 50%) who were scheduled for catheter ablation. Nighttime BP was measured at hourly intervals using home BP monitoring device. Nighttime BP variability was expressed as the coefficient of variation of all readings. LA volume index (mean value, 41.5 ± 13.7 ml/m 2 ) was measured using the modified Simpson’s biplane method with transthoracic echocardiography. Results: In univariate analysis, all systolic and diastolic BP variables were associated with LA enlargement. Multiple regression analysis indicated that nighttime mean systolic/diastolic BPs and their variability remained independently associated with LA volume index (P 2 vs. 32.5 ml/m 2 ; P Conclusions: These findings suggest that higher nighttime mean BP and its variability are associated with LA enlargement. Moreover, the combination of nighttime mean BP and its variability has additional predictive value of LA enlargement. Intensive intervention for these high-risk patients may avoid or delay progression of LA enlargement and consequently reduce subsequent stroke in AF patients with preserved ejection fraction.