A Noninvasive Method to Predict Severity of Coronary Atherosclerosis

The static elastic properties of arterial tree (abdominal aorta and common carotid artery) were studied in 19 normal subjects and in 49 patients with myocardial infarction with an ultrasonic phase-locked echo-tracking system that allows continuous transcutaneous measurement of the arterial diameter. The stifTness index (, which represented the mechanical properties in the arterial wall, was calculated from the relation between systemic blood pressure and the diameter of the artery. Patients with myocardial infarction underwent coronary angiography in their convalescent period to determine involved vessels. In 11 patients, coronary artery was patent; 15 patients had one-vessel disease, 12 had two-vessel disease, and the remaining 11 patients had three-vessel disease. In normal subjects, increasing age was associated with an increase in arterial stiffness. An average value of the stiffiess index of the abdominal aorta was 8.58±3.02 (mean± SD) and that of common carotid artery was 9.17±2.22. In patients with three-vessel disease, these values were significantly higher (22.37± 4.29 in abdominal aorta and 13.17 ±4.56 in common carotid artery) than those in normal subjects. Stiffness index of patients with twoor one-vessel disease was also increased but lower than those in patients with three-vessel disease (p<0.05). Forty-four of 49 patients with infarction had an arterial stiffness index of abdominal aorta higher than the 95% confidence limits of the normal data (p<0.05). Twenty-eight patients were outside the nomogram of common carotid artery (p<0.05). The mechanical properties of these elastic arteries provided sufficiently reliable information on changes caused by atherosclerosis. (Circulation 1989;80:78-86)