Objectives: We tried to determine the effect of stent balloon inflation time on stent expansion and apposition using optical coherence tomography.
Background: Second-generation drug-eluting stents (DES) have thin struts; however, inflation times for optimal stent expansion and apposition are unknown in vivo.
Methods: Subjects included 17 patients (18 de novo coronary artery lesions), in whom Resolute Integrity → (n = 9) and Xience Prime → (n = 9) DES were deployed. All stents were inflated 3 times to the nominal inflation pressure (8.9 ± 0.6 atm) using the stent delivery balloon. The first inflation continued until the stent was angiographically fully expanded; the other 2 lasted 15 and 30 seconds, respectively.
Results: After the first, second, and third inflation of stent balloon, stent area (5.94 ± 1.7, 6.69 ± 1.8, 7.05 ± 1.8 mm(2) , P < 0.001) and stent volume (146.94 ± 59.40, 166.78 ± 69.55, 177.25 ± 69.19 mm(3) , P < 0.001) increased significantly. The number of malapposed struts (18.0 ± 17.0, 7.9 ± 10.2, 7.4 ± 10.8, P < 0.001) and the mean depth of malapposed struts (188.9 ± 75.6, 120.3 ± 101.4, 95.4 ± 86.8 µm, P < 0.001) decreased. Malapposed stent area (0.62 ± 0.32, 0.52 ± 0.21 mm(2) , P < 0.05) and the malapposed stent volume (15.03 ± 7.78, 12.64 ± 5.16 mm(3) , P < 0.05) decreased significantly following the second inflation; the third inflation gave no additional benefits to these parameters. There was no adverse clinical outcome after each stent balloon inflation.
Conclusions: Additional 15 seconds of inflation after the angiographically full expansion of the stent balloon allows better stent expansion and apposition even though the inflation pressure is nominal pressure.
© 2014, Wiley Periodicals, Inc.