The effect of noncritical coronary artery disease on long-term survival.

This study was designed to determine the impact of noncritical (less than 70% narrowing of the luminal diameter) coronary stenoses on the long-term survival rate of patients with coronary artery disease. The survival rate of 3,342 patients with normal coronary arteries (Group 1A) was compared with that of 2,184 patients with only noncritical stenoses (Group 1B). Similarly, the survival rate of 1,128 patients with one or more critical lesions (Group 2A) was compared with that of 5,944 cases with noncritical plus critical lesions (Group 2B). Patients with noncritical lesions had significantly lower 10-year survival rates (85.8%) than did those with normal coronary arteries (90.1%). However, the difference in survival rate was attributable to older age, male sex, and higher prevalence of cigarette smoking, diabetes mellitus, and hypertension in Group 1B than in Group 1A; presence of noncritical stenoses was not a statistically significant independent determinant of survival. Long-term survival rates of the patients with one or more critical lesions (Group 2A) were equivalent to that of patients with critical stenoses plus one or more noncritical lesions (Group 2B). Therefore, 1) patients with only noncritical stenoses have more risk factors for coronary artery disease than do those with normal coronary arteries; 2) these patients have a reduced long-term survival rate that reflects these risk factors rather than the presence of noncritical lesions; and 3) in patients with critical lesions, the presence of additional non-critical stenoses does not affect the long-term survival rate.