Angiographic stenosis progression and coronary events in patients with 'stabilized' unstable angina

Abstract

Background: Recent studies suggest that angiographically complex coronary stenoses are associated with an adverse short-term outcome. It is not known, however, if this applies to unstable angina patients who stabilize on medical therapy.

Methods and results: We prospectively studied 85 consecutive patients with unstable angina who stabilized on medical therapy but were found to require angioplasty for treatment of obstructive coronary disease. Angiography was carried out at admission, and patients were restudied 8 +/- 4 months (mean +/- SD) after the first angiogram. Ischemia-related stenoses were identified and classified as "complex" (irregular borders, overhanging edges, or thrombus) or "smooth" (absence of complex features). Stenosis progression (> or = 20% diameter reduction or new total occlusion) was assessed by automated edge detection. At initial angiography, there were 198 stenoses (> or = 50%, 102), of which 85 (54 complex and 31 smooth) were ischemia related. At restudy, 21 ischemia-related stenoses and 8 non-ischemia-related stenoses progressed (25% versus 7%, P = .001). Seventeen of the 21 ischemia-related stenoses that progressed developed into total occlusion compared with 3 of the 8 non-ischemia-related stenoses (P = .02). Changes in average stenosis severity and in absolute stenosis diameter were significantly larger in ischemia-related stenoses than in non-ischemia-related stenoses (P = .03). Eighteen (34%) complex stenoses progressed, compared with 3 (10%) smooth lesions (P = .02). During follow-up, 1 patient died (myocardial infarction) and 25 patients had nonfatal coronary events that were associated with progression of ischemia-related stenoses in 14 (56%).

Conclusions: In unstable angina patients who stabilize medically, subsequent short-term stenosis progression and coronary events are common. The unstable coronary lesion (particularly complex stenoses) is often not stabilized and will continue to progress over the ensuing months.