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Background: Transthoracic echocardiography (TTE) is routinely used to calculate aortic valve area (AVA) by continuity equation (CE). However, accurate measurement of the left ventricular outflow tract (LVOT) can be difficult and flow acceleration in the LVOT may lead to miscalculation of the AVA., Objective: The aim of our study was to compare AVA measurements by standard TTE, cardiac magnetic resonance imaging (MRI) and a hybrid approach combining both techniques., Methods: AVA was calculated in 38 patients (age 73±9 years) with standard TTE, cine-MRI planimetry and a hybrid approach: Hybrid Method 1: TTE-derived LVOT measurement in the CE numerator was replaced by the MRI assessment of the LVOT and AVA was calculated: (LVOT(MRI)/*LVOT-VTI(TTE))/transaortic-VTI(TTE). Method 2: We replaced the SV in the numerator by the MRI-derived SV and calculated AVA = SV(MRI)/ transaortic-VTI(TTE)., Results: Mean AVA derived by TTE was 0.86 cm(2)±0.23 cm(2) and 0.83 cm(2)±0.3 cm(2) by MRI- planimetry, respectively. The mean absolute difference in AVA was 0.03 cm(2) for TTE vs. MRI planimetry. AVA calculated with method 1 and method 2 was 1.23 cm(2)±0.4 cm(2) and 0.92 cm(2)±0.32 cm(2), respectively. The mean absolute difference between TTE and method 1 and method 2 was 0.37 cm(2) and 0.06 cm(2), respectively (p<0.001)., Conclusion: MRI-planimetry of AVA and hybrid method 2 are accurate and showed a good agreement with standard TTE measurements. Therefore, hybrid method 1 is a reasonable alternative if poor acoustic windows or LVOT flow accelerations limit the accuracy of TTE, particularly in patients at high risk for an invasive hemodynamic study.

Background: Growth differentiation factor-15 (GDF-15), a stress-responsive transforming growth factor-ß-related cytokine, is elevated and independently related to an adverse prognosis in systolic heart failure., Objective: This study aimed to investigate plasma levels of GDF-15 in patients with preclinical diastolic dysfunction or heart failure with normal ejection fraction (HFnEF)., Methods: We evaluated 119 patients with normal ejection fraction referred for an elective coronary angiography, 75 (63%) of whom had coronary artery disease. Subjects were classified as having either mild left ventricular diastolic dysfunction (LVDD grade I, n = 61), HFnEF (LVDD grade II or III, n = 38) or normal diastolic function (controls, n = 20). In a subgroup of 20 subjects, changes in cardiac output (CO) were measured by inert gas rebreathing (InnocorTM) in response to an orthostatic hemodynamic test., Results: Growth differentiation factor-15 levels in HFnEF [median 1.08, interquartile range (0.88-1.30) ng/ml] were significantly higher than in controls [0.60 (0.50-0.71) ng/ml, p = 0.003] and in patients with LVDD grade I [0.78 (0.62-1.04) ng/ml, p < 0.001]. In addition, GDF-15 was significantly elevated in patients with LVDD grade I compared to controls (p = 0.003). Furthermore, GDF-15 was correlated with echocardiographic markers of diastolic dysfunction and was correlated with the magnitude of CO response to the change in body position from standing to supine (r = -0.67, p = 0.005)., Conclusion: Growth differentiation factor-15 levels are elevated in subjects with HFnEF and can differentiate normal diastolic function from asymptomatic LVDD. In addition, GDF-15 is associated with a reduced cardiac output response in the orthostatic hemodynamic test.