Preload augmentation has significant impact on diastolic echocardiographic measurements in patients with cardiac disease but not controls

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Diastolic diagnostics are important among patients with significant heart failure, where large alterations in preload are more common. We hypothesised that preload augmentation has larger impact in hearts with diastolic dysfunction, and that potential re-classification of diastolic parameters induced by increased preload may impact the grading of diastolic function. Purpose The purpose of this study was to demonstrate the impact of preload augmentation on the most commonly used parameters applied for assessment of diastolic function. Methods We included 132 subjects from two different cohorts; the dialysis cohort (n = 50) and the infusion-cohort (n = 82). Cardiac assessment by echocardiography was performed immediately before and after hemodialysis or saline infusion; low loading condition (baseline) and high loading condition (increased preload). The population was divided in two groups defined as controls (n = 50) and cardiac disease (n = 82). Cardiac disease was defined as ischemic heart disease, cardiomyopathy, moderate/severe aortic valve disease, hypertrophy defined by echocardiography, left ventricular ejection fraction <50% or cardiac arrythmia. We compared echocardiographic parameters for diastolic evaluation; early (E) and late (A) diastolic left ventricular filling, E/A, early diastolic mitral annular velocity (e’) and E/e’. Abnormal values applied for re-classification after preload augmentation: E/e’ >14, septal e’ <7 cm/s, lateral e’ <10 cm/s. Results There were no significant differences in indexed augmented preload between controls and cardiac disease; 0.9 ± 0.3 L/m2 vs. 1.0 ± 0.5 L/m2. The control group contained more patients from the infusion- (74%) than the hemodialysis-cohort (26%) p < 0.05. As expected, baseline measurements differed significantly between controls and cardiac disease (Table 1). Preload augmentation significantly increased E and A in the control group, other parameters remained unchanged. In cardiac disease E, but not A, increased significantly. Lateral e’ remained unchanged whereas septal e’ and average E/e’ increased significantly. Re-classification from normal to abnormal values in controls and cardiac disease was: average E/e’ 4% vs. 8%, septal e’ 5% vs. 18%, lateral e’ 3% vs. 16% (Table 2). None of these differences in re-classification between controls and cardiac disease were significant. Conclusion The most commonly applied diastolic parameters are significantly affected by augmented preload amongst patients with cardiac disease, but not controls. Re-classification from normal to abnormal diastolic parameters was not statistically more common in cardiac disease. Hemodynamic status at the time of echocardiography should be considered in the assessment among patients with cardiac disease, as it may have impact on the interpretation of diastolic dysfunction. Abstract Table 1 Abstract Table 2