Coronary artery disease in the Hurler syndrome. Qualitative and quantitative analysis of the extent of coronary narrowing at necropsy in six children.

The amount of cross-sectional area luminal narrowing in each 5 mm segment of each of the four major epicardial coronary arteries (right, left main, left anterior descending and left circumflex) is described at necropsy in six children (aged 3 to 16 years) with the Hurler syndrome. In five patients at least one of the four major coronary arteries was narrowed 76 to 100 percent, and in four of these five patients all four major arteries were narrowed to this extent. Of the 24 major coronary arteries in the six patients, 17 (71 percent) were narrowed 76 to 100 percent at some point. A total of 182 segments were examined from the 24 major coronary arteries, and the extent of narrowing was as follows: 96 to 100 percent, 14 (8 percent); 76 to 95 percent, 61 (34 percent); 51 to 75 percent, 59 (32 percent); 26 to 50 percent, 39 (21 percent) and 0 to 25 percent, 9 (5 percent). By applying a score of 1 to 4 to each 5 mm segment according to its category of narrowing (1 = 0 to 25 percent; 2 = 26 to 50 percent; 3 = 51 to 75 percent and 4 = 76 to 100 percent), the 182 segments had a total score of 570 and a mean score of 3.2, indicating that each segment was narrowed an average of about 67 percent in cross-sectional area. Thus, narrowing of the major epicardial coronary arteries at necropsy is usually diffuse and severe in the Hurler syndrome, which is the cause of the most severe coronary narrowing in childhood.