LUMEN NARROWING AFTER PERCUTANEOUS TRANSLUMINAL CORONARY BALLOON ANGIOPLASTY FOLLOWS A NEAR GAUSSIAN DISTRIBUTION - A QUANTITATIVE ANGIOGRAPHIC STUDY IN 1,445 SUCCESSFULLY DILATED LESIONS

To determine whether significant angiographic narrowing and restenosis after successful coronary balloon angioplasty is a specific disease e ntity occurring in a subset of dilated lesions or whether it is the ta il end of a guassian distributed phenomenon, 1,445 successfully dilate d lesions were studied before and after coronary angioplasty and at 6- month follow-up study. The original cohort consisted of 1,353 patients of whom 1,232 underwent repeat angiography with quantitative analysis (follow-up rate 91.2%). Quantitative angiography was carried out off- line in a central core laboratory with an automated edge detection tec hnique. Analyses were performed by analysts not involved with patient care. Distributions of minimal lumen diameter before angioplasty (1.03 +/- 0.37 mm), after angioplasty (1.78 +/- 0.36 mm) and at 6-month fol low-up study (1.50 +/- 0.57 mm) as well as the percent diameter stenos is at 6-month follow-up study (44 +/- 19%) were assessed. The change i n minimal lumen diameter from the postangioplasty angiogram to the fol low-up angiogram was also determined (-0.28 +/- 0.52 mm). Seventy lesi ons progressed toward total occlusion at follow-up. All observed distr ibution approximately followed a normal or gaussian distribution. Ther efore, restenosis can be viewed as the tail end of an approximately ga ussian distributed phenomenon, with some lesions crossing a more or le ss arbitrary cutoff point, rather than as a separate disease entity oc curring in some lesions but not in others.