Determinants of invasive left atrial pressure in patients with atrial fibrillation

Aims: Estimation of left ventricular (LV) filling pressures in patients with a history of atrial fibrillation (AF) is challenging due to lack of reliable parameters. This study investigates the association between cardiac structure and function and invasive mean left atrial pressure (LAP). Methods and results: This is a multi-centre prospective study enrolling patients undergoing transcatheter ablation for AF. The invasive measurement of LAP was performed at the time of the procedure while the echocardiography within the previous 24 h. A mean LAP ≥ 15 mmHg was considered as increased. Overall, 101 patients were included (mean age 65.8 ± 8.5 years, 68% male, mean LV ejection fraction 56.6 ± 8.0%). No significant differences regarding clinical characteristics were detected between the group of patients with normal (n = 47) or increased LAP (n = 54). The latter showed lower values of LV global longitudinal strain, larger left atrial volumes (LAVs) and worse right ventricular (RV) function. After multivariable adjustment, higher E/e′ ratio (P = 0.041) and minimal LAV index (LAVI min) (P = 0.031), lower peak atrial longitudinal strain (P = 0.030), and RV free wall longitudinal strain (P = 0.037), but not maximal LAV index (LAVI max) (P = 0.137), were significantly associated with mean LAP. The associations were not modified by cardiac rhythm. Overall, LAVI min showed the best diagnostic accuracy to predict elevated LAP (area under the curve 0.703). Conclusion: LA structure and function assessment well correlates with mean LAP in patients with a history of AF. These measures may be used in the assessment of filling pressure in these patients.