Intravascular ultrasound findings of stent fractures in patients with Sirolimus- and Paclitaxel-eluting stents

Abstract

We compared intravascular ultrasound (IVUS) findings of fractures of sirolimus-eluting stents (SESs) versus paclitaxel-eluting stents (PESs). IVUS findings in 6 PES fractures (all in the right coronary artery) in 6 patients from a clinical trial cohort were compared to 14 SES fractures (8 in the right coronary artery, 2 in the left anterior descending coronary artery, and 4 in the left circumflex coronary artery) in 13 patients from our institutional cohort. Comparing PES fractures to SES fractures, IVUS analysis showed (1) similar frequency of complete stent fracture (1 of 6, 17%, vs 3 of 14, 21%, p >0.99), (2) similar frequency of fracture adjacent to calcified plaque or stent metal overlap (5 of 6, 86%, vs 14 of 14, 100%, p = 0.99), (3) more frequent complete malalignment of proximal and distal fragments in PES strut fractures compared to SES fractures (5 of 6, 83%, vs 1 of 14, 7%, p = 0.002), (4) similar stent lengths (45.2 mm, 23.8 to 50.7, vs 39.3 mm, 22.6 to 73.4, p >0.99), (5) similar fracture lengths (0.5 mm, 0.4 to 0.7, vs 0.7 mm, 0.6 to 1.0, p = 0.14), and (6) larger reference external elastic membrane area (15.0 mm(2), 13.5 to 18.0, vs 10.4 mm(2), 6.8 to 13.6, p = 0.01). In conclusion, malalignment of proximal and distal stent fragments more often occurred in PES fractures compared to SES fractures; otherwise the IVUS features of PES and SES fractures were similar.