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 stenoses within the same coronary tree in patients with stable coronary artery disease. Background. Progression of coronary stenosis has prognostic 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 with stable angina who 1) had one complex coronary stenosis and one smooth stenosis in different noninfarct-related coronary vessels at initial coronary angiography, and 2) had a second angiogram after a median interval of 9 months (range 3 to 24). Patients with lesions greater than or equal to 10 mm long, at a major branching point or with > 85% diameter reduction were not included. Coronary lesions were measured quantitatively from comparable end diastolic frames. Stenosis morphology was deter mined qualitatively by two independent observers. Results. All 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 stable angina. Complex and smooth coronary stenoses progress at different rates within the same coronary tree. Complex stenosis morphology itself is an important determinant of progression of stenosis in patients with apparently clinically stable coronary artery disease.