Abstract 2993: Prognostic Value of Changes in Transmitral Flow Velocity Pattern During Leg Positive Pressure in Mild Heart Failure: A Clinical Application of “Preload Stress Echocardiography”
Background: The Doppler transmitral flow velocity pattern has been shown to have prognostic value in patients with heart failure, and patients with a relaxation failure (RF) pattern (E<A) have been recognized to have a better prognosis than those with a pseudonormal (PN) or restrictive pattern (E≥A). However, this differentiation could not be applied in patients with mild heart failure, whose flow pattern often shows a RF pattern. In order to distinguish these patients, we developed “preload stress echocardiography” in which leg positive pressure (LPP) was performed during Doppler recording.
Methods: We performed transthoracic echocardiographic study in 202 stable chronic heart failure patients. Twenty-one of these patients also underwent cardiac catheterization, and left ventricular pressure was recorded during LPP with simultaneous Doppler recording. LV diastolic dysfunction was divided into three categories: stable RF (RF at baseline and during LPP), unstable RF (RF at baseline and PN during LPP) and PN (PN at baseline).
Results: During follow up (mean 548±407 days), 5 cardiac deaths, 37 cases of acute heart failure, 4 of acute myocardial infarction and 7 of stroke were documented. All-cause cardiac events in the unstable RF group were more common than in the stable RF group (11.6% vs. 40.7 %) and were similar to those in the PN group (44.4%). A Kaplan-Meier survival curve showed that the cardiac event-free rate was significantly lower in the unstable RF group than in the stable RF group (log rank p=0.0011). By multivariate logistic regression analysis, unstable RF (odds ratio 8.0, 95% confidence interval 2.8 to 22.8, p<0.001) and E/e′ >15 (odds ratio 4.1, 95% confidence interval 1.2 to 6.7, p=0.022) were independent predictors of all-cause cardiac events.
Conclusion: The change in transmitral flow velocity pattern by preload increment provides additional prognostic information over resting conventional Doppler echocardiographic parameters. LPP is a useful method for “preload stress echocardiography” that achieves noninvasive preload augmentation during echocardiographic examination.