Letter by Dokainish Regarding Article, “Tissue Doppler Imaging in the Estimation of Intracardiac Filling Pressure in Decompensated Patients With Advanced Systolic Heart Failure”
To the Editor:
In their recent article, Mullens et al1 tested the ratio of early transmitral velocity to tissue Doppler mitral annular early diastolic velocity (E/Ea) in 106 patients with left ventricular ejection fraction (LVEF) ≤30% on admission and after treatment for decompensated heart failure. They found no correlation between E/Ea and pulmonary capillary wedge pressure (PCWP), particularly in patients with larger LV volumes, more impaired cardiac indexes, and cardiac resynchronization therapy. This study tested previously validated and commonly used echo Doppler variables in the real-world setting, especially in patients with severe systolic heart failure requiring intravenous therapy, where such variables have diagnostic and therapeutic importance.
These findings are of particular interest because they contrast with correlations between E/Ea and PCWP found in prior investigations using similar patients.2,3 Commendably, the authors divided the population into patients with cardiac resynchronization therapy and those without to account for the impact of cardiac pacing on myocardial longitudinal velocities, particularly in the septum. Nonetheless, the authors did not find a correlation between E/Ea and PCWP in these patients, and they found weak correlations between mitral deceleration time, mitral E/late diastolic velocity ratio (A), and left atrial volume and PCWP. Weak correlations of such conventional echo Doppler variables with PCWP (in particular, of mitral deceleration time) also contrast with findings by previous investigators4 and add to the uniqueness of the current article.
One of the main reasons that this study discovered different findings than prior investigations is likely technical: As seen in Figure 5, the lateral Ea was interpreted as 14.8 cm/s,1 a value much too high for a patient with LVEF ≤30% (who normally would have a lateral Ea ≤8 cm/s).2 The apparent overinterpretation of the Ea value appears to be due to spectral broadening, resulting in an overestimation of Ea and an underestimation of E/Ea. Thus, one wonders whether such measurement issues were systemic in this study. Similarly, it is curious that, in Figure 5, a patient with such an elevated E/late diastolic ratio and rapid mitral deceleration time had a simultaneous PCWP of only 14 mm Hg,1 which is in stark contrast to the findings of prior studies.4 Therefore, the true simultaneity of the PCWP with respect to the Doppler measurements, including E/Ea, could potentially be questioned.
I commend the authors on such a thought-provoking study of Doppler indices in the real world of severe systolic heart failure. As recommended by experts in the field,5 no single echo-Doppler measure should ever be used in isolation for the assessment of LV filling pressures. Rather, a constellation of findings (eg, mitral inflow, tissue Doppler, left atrial size, and pulmonary venous measurements, the latter of which were not reported in this study and are of particular use in this patient population) should be used for the accurate estimation of LV filling pressures, which echo-Doppler readily and reproducibly provides.
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.
Dokainish H, Zoghbi WA, Al-Bakshy FA, Dhir M, Quinones MA, Nagueh SF. Optimal noninvasive assessment of LV filling pressures: a comparison of tissue Doppler echocardiography and BNP in patients with pulmonary artery catheters. Circulation. 2004; 109: 2432–2439.
Nishimura RA, Appleton CP, Redfield MM, Ilstrup DM, Holmes DR Jr, Tajik AJ. Noninvasive Doppler echocardiographic evaluation of left ventricular filling pressures in patients with cardiomyopathies: a simultaneous Doppler echocardiographic and cardiac catheterization study. J Am Coll Cardiol. 1996; 28: 1226–1233.