Four-year prognosis of 254 patients after acute myocardial infarction

The present study was undertaken to determine whether left ventricular diastolic function can be used as a measure for assessing prognosis of patients with acute myocardial infarction. The subjects were 254 patients who had Tc-99m gated blood pool scintigraphy within one month after the onset of myocardial infarction and could be followed up for the subsequent 4 years. The following indices for left ventricular diastolic function were calculated from the time activity curve of the left ventricle: time to peak filling, time to peak filling/t, peak filling rate, peak filling rate/t, 1/3 filling rate/t, and time per beat. On the basis of the morphology of the time activity curve and the primary differential curve, left ventricular diastolic function was visually assessed as normal (Group 0, n=30), slightly decreased (Group 1, n=98), moderately decreased (Group 2, n=81) and severely decreased (Group 3, n=45). The incidences of cardiac failure and cardiac death were remarkably increased when left ventricular ejection fraction (LVEF) was less than 30%. The incidence of cardiac failure tended to be increased in patients with severer diastolic function; it was remarkably high in Group 3. Cardiac failure was more often associated with more decreased diastolic function, even if LVEF was 40% or more. These findings suggest that left ventricular diastolic function may be helpful for assessing prognosis of acute myocardial infarction. (N.K.)