Vascular tissue reaction to acute malapposition in human coronary arteries: sequential assessment with optical coherence tomography.
BACKGROUND
The vascular tissue reaction to acute incomplete stent apposition (ISA) is not well known. The aim of this study was to characterize the vascular response to acute ISA in vivo and to look for predictors of incomplete healing.


RESULTS
Optical coherence tomography studies of 66 stents of different designs, implanted in 43 patients enrolled in 3 randomized trials, were analyzed sequentially after implantation and at 6 to 13 months. Seventy-eight segments with acute ISA were identified in 36 of the patients and matched with the follow-up study by use of fiduciary landmarks. The morphological pattern of healing in the ISA segments was categorized as homogeneous, layered, crenellated, bridged, partially bridged, or bare, depending on the persistence of ISA and on the coverage. After 6 months, acute ISA volume decreased significantly, and 71.5% of the ISA segments were completely integrated into the vessel wall. Segments with acute ISA had higher risk of delayed coverage than well-apposed segments (relative risk 2.37, 95% confidence interval 2.01-2.78). Acute ISA size (estimated as ISA volume or maximum ISA distance per strut) was an independent predictor of ISA persistence and of delayed healing at follow-up.


CONCLUSIONS
Neointimal healing tends to reduce ISA, with the malapposed stent struts often integrated completely into the vessel wall, resulting in characteristic morphological patterns. Coverage of ISA segments is delayed with respect to well-apposed segments. The larger the acute ISA, the greater the likelihood of persistent malapposition at follow-up and delayed healing.
Erasmus Medical Centre-Thoraxcentre, Rotterdam, The Netherlands. jlgutierrez@medynet.com
Juan Luis
JL
Gutiérrez-Chico
Joanna
J
Wykrzykowska
Eveline
E
Nüesch
Robert Jan
RJ
van Geuns
Karel T
KT
Koch
Jacques J
JJ
Koolen
Carlo
C
di Mario
Stephan
S
Windecker
Gerrit-Anne
GA
van Es
Pierre
P
Gobbens
Peter
P
Jüni
Evelyn
E
Regar
Patrick W
PW
Serruys
D000368:Aged; D017130:Angioplasty / Q000009:adverse effects*; D023921:Coronary Stenosis / Q000473:pathology* / Q000601:surgery*; D003331:Coronary Vessels / Q000473:pathology* / Q000601:surgery; D054855:Drug-Eluting Stents / Q000009:adverse effects / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011379:Prognosis; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*; D011859:Radiography; D016032:Randomized Controlled Trials as Topic; D041623:Tomography, Optical Coherence