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Is core laboratory essential for using echocardiography in clinical trials? Controlled vs random error.

Please see page 263 for the article by Hole et al. (doi:10.1053/euje.2002.0167) to which this editorial pertains. Left ventricular remodelling is a natural, but harmful process after an acute myocardial infarction. The infarcted segments become thinner, conducive to being stretched, and even the viable myocardial segments dilate due to mechanical and neurohormonal changes taking place in this clinical setting. The extent of left ventricular remodelling is determined by the size, location, and transmurality of myocardial infarction. The left ventricular dilatation and contractile dysfunction distort normal elliptical left ventricular geometry to a more spherical shape, resulting in worsening of diastolic function and haemodynamically significant mitral valve regurgitation, which perpetuate the cycle of left ventricular remodelling. It is not, therefore, surprising that left ventricular volume was found to be one of the most important prognostic factors in patients with acute myocardial infarction. When dilatation of the left ventricle is minimized or reversed by a combination of treatments, a patient’s prognosis does improve. Examples of these treatments are acute reperfusion therapy (thrombolysis, percutaneous coronary intervention, or surgical bypass procedure), ACE inhibitor started during acute phase of myocardial infarction, mechanical reduction of left ventricle size by surgery, a passive constraint device, and biventricular pacing. Echocardiography is the most widely used imaging technique to assess left ventricular size and volume, due to the advantages of being portable, versatile and widely available, even though radionuclide and cardiac magnetic resonance imaging are considered better methods for measurement of left ventricular volume. Despite the practical advantages of echocardiography to assess left ventricular size and volume serially in clinical trials, it has the disadvantage of being more operator dependent in acquisition and interpretation. For echocardiography to be reliable in the measurement of left ventricular volume, both acquisition of the images and data analysis should be reliable and reproducible. During the