THE RELATIONSHIP BETWEEN ECHOCARDIOGRAPHICALLY ASSESSED E/EM AND INVASIVELY MEASURED LEFT ATRIAL PRESSURE

Background: A ratio between the magnitude of E-wave of the early diastolic mitral inflow velocity and early diastolic mitral annulus velocity (E/Em) is used to estimate left ventricular (LV) filling pressures and is incorporated in scores facilitating the diagnosis of heart failure with preserved LV ejection fraction (HFpEF). The recent version of HF guidelines and H2FPEF score proposed the E/Em≥9 to be the optimal cut-off value to predict elevated LV filling pressures. 

Purpose: To correlate E/Em with invasively measured left atrial (LA) pressures at rest and during exercise and determination the optimal cut-off values.

Methods: 223 patients (age 60± 10 years, 65% males) with HF symptoms, LV ejection fraction ≥ 50%, and nonvalvular atrial fibrillation (AF) that were scheduled for AF ablation was analyzed. Mean LA pressure (mLAP) was measured at rest and upon a 3-min isometric handgrip exercise. Elevated resting and exercise-induced mLAP (r-LAP and e-LAP) were defined as mLAP≥15 mmHg and mLAP≥25 mmHg, respectively. ROC analysis was used to establish the optimum cut-off points.

Results:Elevated r-mLAP and e-mLAP were found in 16.6% and 9.4% of patients, respectively.E/Em showed a significant but rather weak correlation with both r-mLAP (r2= 0.11) and e-mLAP (r2= 0.10), p < 0.0001 for both, Figure.The optimum E/Em cut-off value was≥8.3 to predict elevated r-mLAP and ≥9.1 to predict elevated e-mLAP. A cut-off value of ≥9 offered the sensitivity of 56.3% and specificity of 72.4% for the prediction of elevated r-mLAP and the sensitivity of 68.4% and specificity of 71.7% for the prediction of elevated e-mLAP.

Conclusion: The predictive power of E/Em for both r-mLAP and e-mLAP is weak. Nevertheless, the cut-off value of 9 to identify elevated LV filling pressures seems to be optimally selected.