Abstract 17421: Echocardiographic Assessment of Diastolic Function and Invasive Measures of Left Ventricular Filling Pressure and Relaxation

Abstract

Background Although echocardiographic assessment of left ventricular diastolic dysfunction (DD) has prognostic value, its correlation with invasively measured filling pressures and markers of relaxation is not clear. We sought to evaluate the relationship between DD and ventricular filling pressure and relaxation.

Methods Diastolic function was assessed in a blinded fashion on images acquired within 24 hours of left heart catheterization on 459 patients. Patients with atrial fibrillation, mitral stenosis, severe mitral or aortic regurgitation and those with inadequate image quality were excluded. Grade of DD was determined according to established guidelines. Left ventricular end-diastolic pressure (LVEDP) was measured at heart catheterization and Tau was calculated according to the formula Tau = isovolumic relaxation time / (ln systolic aortic pressure - ln LVEDP) as an index of relaxation. Serum B-type natriuretic peptide (BNP) values were log-transformed due to a non-normal distribution. The effect of DD on each parameter was tested with analysis of variance and post-hoc Tukey tests.

Results There were 56 patients with normal diastolic function, 122 with grade 1 DD, 194 with grade 2 DD and 87 with grade 3 DD. LVEDP was significantly higher in grade 3 DD than in normal patients (p=0.010), but not in the other groups. BNP was increased in patients with grade 2 DD (p=0.018) and grade 3 DD (p<0.001). There was a relationship between grade and Tau (p=0.004), with Tau being greater than normal in grades 1 and 3 DD (see figure). Trends remained the same after controlling for left ventricular ejection fraction (LVEF) <>45%.

Conclusion Advanced DD (grade 3) as determined by echocardiography is correlated with delayed relaxation and elevations in BNP and LVEDP. Less advanced grades of DD do not distinguish LVEDP. The pattern of grade 2 DD seen on echo may relate to more chronic elevations in filling pressure, as reflected by BNP.