731-3 Remodelling of Coronary Arteries After Balloon Angioplasty: In Vivo Documentation in Patients Using Consecutive Intravascular Ultrasound

Abstract

The objective of the present study was to determine the relative importance of arterial remodelling compared with intimal hyperplasia in restenosis after balloon angioplasty (PTCA). Intravascular ultrasound (IVUS) and quantitative coronary angiography (QCA) of the dilated vessel were performed in 52 pats with coronary artery disease immediately after PTCA. In a total of 42 pats (80%) of this group IVUS and QCA were repeated after 6 months (5.9 ± 0.2 months). IVUS was performed with 2.9F or 3.5F catheters. Care was taken to identify the angioplasty segment with great precision. Restenosis, defined as a reduction >50% of minimal lumen diameter (MLD), was established by QCA. Lumen area and vessel area (i.e. the difference between the area within the media-adventitia interface and the lumen area) were determined by IVUS. After PTCA there was a lumen area of 6.36 ± 1.82 mm 2 and a vessel area of 16.33 ± 4.19 mm 2 . At 6 months control, a lumen area of 4.71 ± 1.47 mm 2 (p ≤ 0.05) and a vessel area of 14.88 ± 4.28 mm 2 (p ≤ 0.05) were ascertained. In 10/42 (24%) pats restenosis was present. In this group, a reduction of lumen area from 6.18 ± 1.45 mm 2 immediately after PTCA to 2.95 ± 1.28 mm 2 (-3.23 ± 0.91 mm 2 ; p ≤ 0.01) and a concomitant decrease of vessel area from 17.41 ± 4.01 mm 2 to 14.76 ± 3.9 mm 2 (-2.65 ± 0.82 mm 2 ; p ≤ 0.01) were demonstrated. Thus, this consecutive IVUS study in patients demonstrates that a reduction in circumferential dimension of the coronary artery is responsible for in mean 82% of late luminal loss in patients with restenosis after PTCA.