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We congratulate Cazzaniga et al on their study focusing on the heart (Gut 2007;56:869–75), an often neglected organ when assessing a patient with cirrhosis. The cardiovascular changes in cirrhosis are complex and measurement of the ratio between the early maximal ventricular filling velocity and the late filling velocity (E/A ratio) after the insertion of a transjugular intrahepatic portosystemic shunt (TIPS) may provide a powerful tool for identifying a poorly responding subgroup of patients.
However, we have certain observations about the study and its conclusions. Specifically, whether it is possible to diagnose diastolic dysfunction (DD) using the E/A ratio alone, given its dependence on loading conditions and age.
The use of echocardiography is the cornerstone of a comprehensive evaluation of DD. However, it is operator dependent and prone to interobserver variation and bias. Lack of an independent observer to verify the measured calculations weakens this study.
Loading conditions are of critical importance when interpreting diastolic function based on the E/A ratio. Any increase in preload will cause an increase in left atrial pressure and hence the early velocity of ventricular filling.
In the above study, all patients showed an increase in E/A ratio, corroborating the view that the E/A ratio changes with an increase in preload (left ventricular end‐diastolic volume). Even in the subgroup whose E/A ratio was <1 at 28 days (group 1), the E/A ratio rose to 0.97 (11), which is probably normal and expected for that age group (65 years).
With increasing age there is a physiological decrease in E/A ratio.1 Although the difference between the groups' ages (65 vs 59) was not statistically significant, this might have been owing to the small sample size.
More relevant to the outcome, may have been the drop in the left ventricular ejection fraction in the group with the poor outcome, despite the increased preload. Hence, rather than DD we could interpret the data as unmasking a deterioration in systolic function.
The assertions about DD might have been made clearer had more “load‐independent” methods for assessing DD been used.
Colour M‐mode echocardiography using the early diastolic flow propagation velocity as the blood flows from the mitral valve to the apex,2 or mitral annular Doppler tissue imaging measurements of the myocardium during the cardiac cycle3 are two load‐independent methods that can be used, in conjunction with the E/A ratio, to better characterise DD.
In summary, the importance of cardiac dysfunction in patients undergoing TIPS is significant. Although Cazzaniga et al may show that the E/A ratio after TIPS is possibly a powerful indicator of prognosis, it cannot be reliably used to diagnose diastolic dysfunction on its own. Load‐independent methods such as colour M‐mode echocardiography, or Doppler tissue imaging, may help to clarify the contribution of diastolic dysfunction in cirrhosis and may improve patient selection for TIPS.