RAPID ANGIOGRAPHIC PROGRESSION OF TARGET AND NONTARGET STENOSES IN PATIENTS AWAITING CORONARY ANGIOPLASTY

Objectives. Our aim was to compare the short-term evolution of ''targe t'' versus ''nontarget'' stenoses in patients awaiting coronary angiop lasty. Background. Coronary angioplasty is effective therapy for angin a pectoris, but coronary events occur after successful angioplasty tha t are caused by both restenosis and progression of mild preexisting no ntarget stenoses. Methods. We prospectively studied 161 consecutive pa tients with stable angina (124 men and 37 women), After diagnostic ang iography, target stenoses for angioplasty and nontarget lesions were i dentified. Patients were put on a routine waiting list and followed up regularly until repeat coronary arteriography was performed (mean +/- SD 7 +/- 3 months), either immediately before angioplasty (138 patien ts) or soon after an acute coronary event (23 patients), if one occurr ed. Stenosis diameter was measured by using computerized arteriography . Progression of disease was defined as greater than or equal to 20% l esion diameter reduction, new total occlusion or development of a ''ne w'' stenosis greater than or equal to 30%. Results. At study entry, th e mean diameter of target (n = 207) and nontarget (n = 184) lesions wa s 68 +/- 9% and 38 +/- 9%, respectively (p < 0.001). Disease progressi on occurred in 33 patients (20%). Seven new lesions (one total occlusi on) developed. Eighteen target (9%) and 15 nontarget (8%) stenoses pro gressed. The power of the study to detect a difference of 1% between t he risks of progression of target and nontarget stenoses with a 90% pr obability was <0.1. Total occlusion developed in 15 (83%) of the 18 ta rget and 6 (40%) of the 15 nontarget stenoses (p = 0.03). During follo w-up, a myocardial infarction developed in 3 patients (2%) and unstabl e angina in 20 (12%), These coronary events were associated with progr ession of target stenoses in 10 patients and nontarget stenoses in 7 a nd with the development of new lesions in 1. In five patients coronary events were not associated with stenosis progression, Conclusions. De spite differences in baseline severity, a similar proportion of target and nontarget lesions progressed rapidly However, target stenoses wer e more likely than nontarget lesions to progress to total occlusion. P rogression of nontarget stenoses may contribute to recurrence of angin a and new coronary events after successful angioplasty and should be c onsidered when developing strategies aimed at improving outcome after angioplasty.