Purpose: To determine the time course of elastic recoil (ER) in the first 15min after successful percutaneous transluminal coronary angioplasty (PTCA).
Methods: One hundred and fifty four patients, with stable or unstable angina were successfully submitted to PTCA. Coronary angiography was undertaken shortly after balloon deflation and repeated 5, 10 and 15 min thereafter. Quantitative coronary angiography was performed with the aid of an eletronic caliper. We calculated the minimal luminal diameter (MLD) and elastic recoil in all angiograms.
Results: The average artery's reference diameter was 3.09 +/- 0.61mm and the maximal balloon diameter was 2.95 +/- 0.52mm. MLD before the procedure was 0.65 +/- 0.42mm reaching 2.23 +/- 0.55mm immediately after dilatation (p < 0.0001), and decreasing to 2.09 +/- 0.47mm at 5min (p < 0.0001), 2.01 +/- 0.47 at 10min (p < 0.0001) and to 1.91 +/- 0.56mm at 15min (p < 0.0001). ER increased during the 1st 15min after PTCA, averaging 34.29 +/- 20.40%. In the group of patients whose balloon/artery relationship was < or = 1, the total ER was 0.90 +/- 0.74mm at 15min and 1.20 +/- 0.50mm when the ratio was > 1 (p < 0.0001). We noted that ER in the group of patients with residual stenosis ranging from 30 to 50% at the immediate angiogram after PTCA was greater than in the group whose residual stenosis was less than 30%.
Conclusion: ER is a dynamic and progressive phenomenon taking place within the 1st 15 min after a successful PTCA. Total ER was 34.29 +/- 20.40% at 15min and was greater when balloon/artery relationship was > 1. Residual stenosis ranging from 30 to 50% in the control immediately after the procedure is a predictive factor of greater ER in the 15min following PTCA.