BACKGROUND: Aortic valve area (AVA) is commonly determined from 2-dimensional transthoracic echocardiography (2D TTE) by continuity equation; however, this method relies on geometric assumptions of the left ventricular outflow tract which may not hold true . This study compared mean differences and correlations for AVA by planimetric (2-dimensional transesophageal echocardiography [2D TEE], 3-dimensional transesophageal echocardiography [3D TEE], 3-dimensional transthoracic echocardiography [3D TTE], multi-detector computed tomography [MDCT], and magnetic resonance imaging [MRI] ) with hemodynamic methods (2D TTE and catheterization) using pairwise meta-analysis .
METHOD: Ovid MEDLINE®, Ovid EMBASE, and The Cochrane Library (Wiley) were queried for studies comparing AVA measurements assessed by planimetric and hemodynamic techniques . Pairwise meta-analysis for mean differences (using random effect model) and for correlation coefficients (r) were performed .
RESULTS: Forty-five studies (3014 patients) were included . Mean differences between planimetric and hemodynamic techniques were 0.12â¯cm2 (95% CI 0.10-0.15) for AVA (pooled râ¯=â¯0.84; 95% CI 0.76-0.90); 1.36cm2 (95% CI 1.03-1.69) for left ventricular outflow tract area; and 0.13â¯cm (95% CI 0.07-0.20) for annular diameter (pooled râ¯=â¯0.76; 95% CI 0.64-0.94); 0.67â¯cm2 (95% CI 0.59-0.76) for annular area (pooled râ¯=â¯0.74; 95% CI 0.55-0.86).
CONCLUSIONS: Planimetric techniques slightly, but significantly, overestimate AVA when compared to hemodynamic techniques.