Abstract 4726: How Reliable is Left Atrial Volume in Estimating Left Atrial Pressure in Advanced Heart Failure Patients? Three-Dimensional Echocardiographic and Catheterization Studies
Previous work has suggested that left atrial (LA) size reflects LA pressure but direct correlative studies of pressure and volume are scant. Furthermore, evaluation of LA size has typically been based on 1-dimensional measures or 2D echo-derived LA area or volume. The aim of this study was to explore whether 3D LA volume could accurately indicate LA pressure in advanced heart failure (HF) patients, in whom filling pressure estimation is clinically relevant. We studied 32 patients with advanced HF both with 3D echo (3DE) performed simultaneously or close to the time of pulmonary capillary wedge pressure (PCWP) measurement by cardiac catheterization. From full volume 3D data sets of the left heart, maximum LA volume (MaxLAV) and minimum LA volume (MinLAV), and volumes indexed to body surface area (MaxMAVI and MinLAVI) were calculated. Mean PCWP was obtained from standard invasive recordings.
Results: The mean LVEF was 23±8. The MaxLAV was 101±38 ml with a range of 34 to 173. MaxLAVI was 50±16 ml/m2 with a range of 19 to 81. MinLAV was 76±37 with a range of 19 to 145. MinLAVI was 38±16 ml/m2, with a range of 12 to 72. The PCWP (mm Hg) was 21±8 with a range of 2 to 34. The correlation between PCWP, and MaxLAV, MaxLAVI, MinLAV and MinLAVI were respectively r=0.193, p=0.28; r=0.25, p=0.16; r=0.24, p=0.17; and r=0.31, p=0.08. Within the group, there were some patients with normal or low PCW but with larger LA volumes (>median) while some patients with high filling pressures did not necessarily have higher LA volumes.
Conclusion: In advanced HF patients, maximum or minimum LA volumes do not correlate with PCWP. LA remodeling and depletion of LA volume reserve in these patients is most likely responsible for the lack of correlation. Thus, in advanced HF patients, LA volume cannot be used to assess left heart filling pressure.