ANGIOGRAPHIC STENOSIS PROGRESSION AND CORONARY EVENTS IN PATIENTS WITH STABILIZED UNSTABLE ANGINA

Background Recent studies suggest that angiographically complex corona ry stenoses are associated with an adverse short-term outcome. Tt is n ot known, however, if this applies to unstable angina patients who sta bilize on medical therapy. Methods and Results We prospectively studie d 85 consecutive patients with unstable angina who stabilized on medic al therapy but were found to require angioplasty for treatment of obst ructive coronary disease. Angiography was carried out at admission, an d patients were restudied 8+/-4 months (mean+/-SD) after the first ang iogram. Ischemia-related stenoses were identified and classified as '' complex'' (irregular borders, overhanging edges, or thrombus) or ''smo oth'' (absence of complex features). Stenosis progression (greater tha n or equal to 20% diameter reduction or new total occlusion) was asses sed by automated edge detection. At initial angiography, there were 19 8 stenoses (greater than or equal to 50%, 102), of which 85 (54 comple x and 31 smooth) were ischemia related. At restudy, 21 ischemia-relate d stenoses and 8 non-ischemia-related stenoses progressed (25% versus 7%, P=.001). Seventeen of the 21 ischemia-related stenoses that progre ssed developed into total occlusion compared with 3 of the 8 non-ische mia-related stenoses (P=.02). Changes in average stenosis severity and in absolute stenosis diameter were significantly larger in ischemia-r elated stenoses than in non-ischemia-related stenoses (P=.03). Eightee n (34%) complex stenoses progressed, compared with 3 (10%) smooth lesi ons (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-ter m stenosis progression and coronary events are common. The unstable co ronary lesion (particularly complex stenoses) is often not stabilized and will continue to progress over the ensuing months.