Comparison at necropsy by age group of amount and distribution of narrowing by atherosclerotic plaque in 2995 five-mm long segments of 240 major coronary arteries in 60 men aged 31 to 70 years with sudden coronary death.

A comparison of the amount and distribution of coronary arterial narrowing by atherosclerotic plaque at necropsy is described in each of four decades (31 to 70 years) of 60 male victims of sudden coronary death (SCD). Of 2995 five-mm segments examined (mena 50 per patient) of the four major (left main [LM], left anterior descending [LAD], left circumflex [LC], and right) coronary arteries, no significant differences were observed in the mean percent of 5 mm long segments narrowed severely (76% to 100% in cross-sectional area [XSA]) in each decade: 33% in the five patients aged 31 to 40 years, 29% in the 27 patients aged 41 to 50 years, 26% in the 18 patients aged 51 to 60 years, and 30% in the 10 patients aged 61 to 70 years. The mean percent of 5 mm segments severely narrowed was significantly (p less than 0.05) greater in the proximal halves than in the distal halves of the LAD, LC, and right coronary arteries in only the two older decades. The mean percent of 5 mm segments minimally (0% to 25%) narrowed, however, was significantly higher in the younger than in the older decades. Thus, as groups, both young and old victims of SCD have similar amounts of severe coronary narrowing, but the younger victims have a greater proportion of their major coronary arteries minimally narrowed.