title: Long-term follow-up of attenuated plaques in patients with acute myocardial infarction: an intravascular ultrasound substudy of the HORIZONS-AMI trial.
abstract: BACKGROUND
  Intravascular ultrasound (IVUS)-attenuated plaque is characterized by absence of ultrasound signal behind hypoehcoic plaque and is seen almost exclusively in acute coronary syndromes.
  
  
  RESULTS
  We analyzed poststenting and 13-month follow-up IVUS in 186 patients (195 lesions) with acute myocardial infarction who underwent primary percutaneous coronary intervention. The primary prespecified IVUS end point was the in-stent percent net volume obstruction at follow-up. Overall, 70.3% of lesions contained attenuated plaques at baseline. During follow-up, attenuation scores decreased significantly, behind paclitaxel-eluting stents (PES) (14.1 [11.9, 16.3] to 7.7 [5.4, 9.9], P<0.0001), behind bare metal stents (BMS) (18.5 [13.2, 23.8] to 12.0 [6.7, 17.3], P<0.0001), and within distal references (3.1 [1.1, 5.1] to 2.2 [0.2, 4.1], P=0.02). There was a greater calcium increase in attenuated than nonattenuated plaques in both PES (Δcalcium score of 4.4 [3.3, 5.5] versus 1.6 [0.9, 2.3], P<0.0001) and BMS (Δcalcium score of 4.1[2.3, 5.9] versus 1.0 [0.3, 1.7], P=0.001). PES implantation into attenuated plaques was particularly associated with late acquired stent malapposition (36.8% versus 15.4% compared with nonattenuated plaques treated with PES, P=0.03). Changes in attenuation scores correlated with changes in calcium scores both in PES (Pearson correlation coefficient=-0.456, P<0.0001] and BMS sites (Pearson correlation coefficient=-0.450, P=0.0006). In 3 years of follow-up, target lesion revascularization was significantly less in patients with attenuated plaque at baseline (6.0% versus 17.4% in patient without attenuated plaques, P=0.019).
  
  
  CONCLUSIONS
  Attenuated plaques evolved into calcified plaques after stent implantation. Attenuated plaque is associated with late acquired stent malapposition and related less target lesion revascularization (consistent with less neointimal hyperplasia), especially after PES implantation in patients with acute myocardial infarction.
  
  
  BACKGROUND
  URL: http://www.clinicaltrials.gov. Unique identifier: NCT00433966.
authors.affiliation: Cardiovascular Research Foundation/Columbia University Medical Center, New York, NY, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Xu
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
authors.forename: Takashi
authors.initials: T
authors.lastname: Kubo
authors.forename: Xiaofan
authors.initials: X
authors.lastname: Wu
authors.forename: Ning
authors.initials: N
authors.lastname: Guo
authors.forename: Junqing
authors.initials: J
authors.lastname: Yang
authors.forename: Bernhard
authors.initials: B
authors.lastname: Witzenbichler
authors.forename: Giulio
authors.initials: G
authors.lastname: Guagliumi
authors.forename: Bruce
authors.initials: B
authors.lastname: Brodie
authors.forename: Ovidiu
authors.initials: O
authors.lastname: Dressler
authors.forename: Ecaterina
authors.initials: E
authors.lastname: Cristea
authors.forename: Helen
authors.initials: H
authors.lastname: Parise
authors.forename: Roxana
authors.initials: R
authors.lastname: Mehran
authors.forename: Gregg W
authors.initials: GW
authors.lastname: Stone
authors.forename: Akiko
authors.initials: A
authors.lastname: Maehara
mesh_terms: D000368:Aged; D019917:Blood Vessel Prosthesis Implantation; D023903:Coronary Restenosis / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000601:surgery*; D054855:Drug-Eluting Stents / Q000706:statistics & numerical data; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery; D054318:No-Reflow Phenomenon / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery; D017239:Paclitaxel / Q000008:administration & dosage / Q000009:adverse effects; D011183:Postoperative Complications / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000706:statistics & numerical data*
chemical_list: D017239:Paclitaxel