Aims: A high degree of collateral supply to a vascular area where a percutaneous transluminal coronary angioplasty (PTCA) has been performed represents a haemodynamic force competing with the antegrade flow through the dilated lesion. Therefore, our purpose was to determine whether patients with restenosis following PTCA have a higher collateral flow to the recipient vessel than patients without restenosis.
Methods and results: In 200 consecutive PTCA patients, an intracoronary pressure-derived collateral flow index (CFI) was determined quantitatively during balloon occlusion, using simultaneous measurements of the mean aortic pressure (P(ao)) and of the intracoronary pressure distal to the occluded stenosis (P(occl)), as well as the estimated central venous pressure (CVP=5 mmHg): CFI=(P(occl)-CVP)/(P(ao)-CVP). Sixty-four patients had an angiographic follow-up examination after at least 2 months, and were subdivided into patients with restenosis (>50% diameter stenosis, n=34) and patients without restenosis (n=30). Patients with restenosis had a significantly higher collateral flow index at the initial coronary angiography than patients without restenosis (0.26 +/- 0.14 vs 0.12 +/- 0.09; P<0.0001).
Conclusions: Patients with restenosis after PTCA show a more extended collateral supply to this recipient area than patients without restenosis. Well developed collaterals to a revascularized region are a risk factor for restenosis of the treated lesion.