Letter by Ogunyankin Regarding Article, “Tissue Doppler Imaging in the Estimation of Intracardiac Filling Pressure in Decompensated Patients With Advanced Systolic Heart Failure”
To the Editor:
I read with interest the article by Mullens et al1 about patients with severe heart failure, and I agree with their important warning that using annular tissue Doppler velocity indices as the sole predictors of elevated left ventricular (LV) filling pressure is inaccurate.
Some points in the article deserve additional clarification. The authors cite published data on the ratio of early transmitral velocity to tissue Doppler mitral annular early diastolic velocity (E/Ea) with pulmonary capillary wedge pressure (PCWP) in a wide range of cardiac patients. However, the strength of the correlation in the validation articles2,3 may not justify the use of the E/Ea ratio as a sole predictor of LV filling pressure or PCWP. For example, in the study by Ommen et al,2 the correlation using the medial annulus E/Ea in their cohort was only 0.64 compared with 0.59 for the mitral inflow Doppler early and late diastolic velocities ratio.
Also, adequate comparison of the current study with others on this subject may be difficult because of methodological differences. Although Ea velocities were obtained from medial and lateral annuli, a universal value of E/Ea of >15 for elevated PCWP, which is applicable to the septal annulus in the study by Ommen et al,2 was used in the current study. For the lateral annulus, Nagueh et al3 used an E/Ea ratio of 10 to identify a PCWP >12 mm Hg. The definition of abnormal PCWP as >15 mm Hg or >18 mm Hg also differentiates the current study from others. It is known that when a higher cutoff point of E/Ea is chosen, the specificity for detecting elevated PCWP is increased at the expense of lower sensitivity.3 The authors found that E/Ea does not strongly correlate with PCWP and is hence unable to substratify advanced grades of filling pressure. Could this result be due to the different threshold for high LV filling pressures?
Single echocardiographic parameters correlate only moderately with catheter measurements because substantial overlap exists between the grades of diastolic function and the range of diastolic pressures within each grade.3,4 In a simultaneous echocardiographic and cardiac catheterization study, in which diastolic function staging was based on a combination of parameters,4 we showed that although almost 80% of the patients with normal diastolic function had an LV mean pressure ≤12 mm Hg, only 35% to 40% of the patients with severe diastolic dysfunction had an LV mean pressure >15 mm Hg. We concluded that a high LV mean pressure has a high negative predictive value in normal diastolic function but a poor positive predictive value in severe diastolic dysfunction. This conclusion is consistent with findings in the current study. Interestingly, a failure to precisely identify elevated filling pressure did not reduce the ability of our diastolic function classification scheme to predict the high 4-year mortality seen in the severe diastolic function group relative to normal.5
I commend the authors for highlighting that assessment of diastolic function is complex and nuanced, as well as for underscoring the need for research on how to accurately assess interval changes in echocardiographic markers of high filling pressures after aggressive treatment that fail to normalize filling pressures.
Mullens W, Borowski AG, Curtin RJ, Thomas JD, Tang WH. Tissue Doppler imaging in the estimation of intracardiac filling pressure in decompensated patients with advanced systolic heart failure. Circulation. 2009; 119: 62–70.
Ommen SR, Nishimura RA, Appleton CP, Miller FA, Oh JK, Redfield MM, Tajik AJ. Clinical utility of Doppler echocardiography and tissue Doppler imaging in the estimation of left ventricular filling pressures: a comparative simultaneous Doppler-catheterization study. Circulation. 2000; 102: 1788–1794.
Ogunyankin KO, Day AG, Lonn E. Cardiac function stratification based on echocardiographic or clinical markers of left ventricular filling pressures predicts death and hospitalization better than stratification by ventricular systolic function alone. Echocardiography. 2008; 25: 169–181.