379 Normal Left Atrial Strain is a Novel, Simple, Reliable and Robust Parameter to Exclude Raised Left Ventricular Filling Pressure - Results from the CATHARSIS Study.

Abstract

Non-invasive assessment of ventricular filling pressure has typically been confounded by poor correlation of standard echocardiographic parameters vs invasive measurements. The novel measurement of left atrial strain as assessed from the apical four-chamber view on transthoracic echocardiography has been suggested as a surrogate for filling pressure. Patients enrolled in the CATHARSIS study undertook comprehensive echocardiography and contemporaneous left heart catheterization (pre-A pressure) whilst nil by mouth. Left atrial strain was assessed using GE Medical Equipment. Maximum atrial strain (reservoir) was assessed in all patients. 140 patients (age 62.0±12.8, female 22%, ejection fraction 56±11%) had left atrial strain 27.1±7.7% with left ventricular pre-A pressure 10±4mmHg. There was a weak linear correlation between invasive pressures and peak LA Strain (r2=0.2, p=0.001). Using a cut-off of ≤12mmHg for normal pre-A pressure and a cut-off of ≥28% for normal left atrial strain yielded a 92% positive predictive power for normal LA Strain predicting normal pre-A pressure. At a threshold of 28%, a reduced left atrial strain did not accurately predict normal vs raised left atrial pressure. Left atrial strain is a novel and feasible parameter which correlates with left ventricular filling pressures. A normal left atrial strain value (≥28%) is highly predictive of normal left ventricular filling pressures.