DIFFERENTIAL PROGRESSION OF COMPLEX AND SMOOTH STENOSES WITHIN THE SAME CORONARY TREE IN MEN WITH STABLE CORONARY-ARTERY DISEASE

Objectives. We sought to compare the evolution of complex and smooth s tenoses within the same coronary tree in patients with stable coronary artery disease.Background. Progression of coronary stenosis has progn ostic significance and may be influenced by local and systemic factors . Stenosis morphology is a determinant of disease progression, but no previous study has systematically assessed progression of complex and smooth stenoses within the same patient. Methods. We studied 50 men wi th stable angina who 1) had one complex coronary stenosis and one smoo th stenosis in different noninfarct-related coronary vessels at initia l coronary angiography, and 2) had a second angiogram after a median i nterval of 9 months (range 3 to 24). Patients with lesions greater tha n or equal to 10 mm long, at a major branching point or with > 85% dia meter reduction were not included. Coronary lesions were measured quan titatively from comparable end diastolic frames. Stenosis morphology w as deter mined qualitatively by two independent observers. Results. Al l patients remained in stable condition during follow up. Progression, defined as an increase in diameter stenosis by greater than or equal to 15% was seen in only eight complex stenoses (16%) but in no smooth lesions (p < 0.01). The severity of complex stenoses changed more than that of corresponding smooth stenoses (mean +/- 1 SD 5.8 +/- 13% vs. -0.06 +/- 6%, p < 0.01). On average, the annual rate of growth was 11. 4 +/- 28% and 1.5 +/- 14% for complex and smooth lesions, respectively (p < 0.01). Conclusions. Few coronary stenoses progress rapidly in st able angina. Complex and smooth coronary stenoses progress at differen t rates within the same coronary tree. Complex stenosis morphology its elf is an important determinant of progression of stenosis in patients with apparently clinically stable coronary artery disease.