Intravascular ultrasound assessment of the relation between early and late changes in arterial area and neointimal hyperplasia after percutaneous transluminal coronary angioplasty and directional coronary atherectomy

Previous serial intravascular ultrasound (IVUS) analysis after percutaneous transluminal coronary angioplasty or directional coronary atherectomy showed (1) early (within 1 month) increase in arterial area, (2) late (1- to 6-month) decrease in arterial area, and (3) an increase in plaque area from immediately to 6 months after intervention. To further understand these findings, we used serial IVUS to study the relations between changes in arterial and plaque area during the follow-up period after coronary intervention. Serial IVUS was performed before intervention and immediately, 24 hours, 1 month, and 6 months after percutaneous transluminal coronary angioplasty (n = 35) or directional coronary atherectomy (n = 26) in 57 patients. Arterial, lumen, and plaque areas were measured at the lesion site with the smallest preintervention and follow-up lumen areas at all time points. The increase in plaque area in the first month after intervention was accompanied by an equal or greater increase in arterial area (r = 0.670, p <0.0001). There was a decrease in arterial area from 1 to 6 months after intervention, which correlated inversely with both the increase in plaque area (r = 0.434, p <0.0001) or arterial area (r = 0.515, p <0.0001) during the first month after intervention and directly with the 1- to 6-month increase in plaque area (r = 0.460, p <0.0001). Comparison of the late (1 to 6 months) and early (within 1 month) Δarterial versus Δplaque area regression lines suggested that the late decrease in arterial area was superimposed on the relation between Δarterial area and Δplaque area. These relations were especially strong in restenotic (vs nonrestenotic) lesions. The early increase and late decrease in stenosis arterial area and neointimal hyperplasia appear to be interrelated, especially in restenotic stenoses.