Morphological changes and clinical impact of unstable plaques within untreated segments of acute myocardial infarction patients during a 3-year follow-up: an analysis from the HORIZONS-AMI trial.
OBJECTIVE
Plaque ruptures and attenuated plaques are considered to be unstable and have been identified in both culprit and nonculprit lesions of patients with ST-segment elevation myocardial infarction (STEMI). However, there are limited data available on the natural evolution of these plaques and their long-term clinical outcome. We investigated the natural evolution and long-term impact of plaque ruptures and attenuated plaques in untreated segments of infarct-related arteries in patients with STEMI.


METHODS
In the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction trial, 389 patients with 429 lesions underwent intravascular ultrasound (IVUS) at baseline. Follow-up IVUS at 13 months was conducted in 245 patients. Three-year follow-up data were available for all patients.


RESULTS
Segments not treated between baseline and follow-up were compared. Baseline IVUS identified 29 plaque ruptures in 27 patients (7%). Of 11 plaque ruptures with follow-up IVUS, four healed and seven persisted. Conversely, through follow-up IVUS, nine new plaque ruptures in nine patients (4%) were identified. Attenuated plaques were identified in 31 of 38 plaque ruptures (81.5%), of which 24 were in the same circumferential segment as the ruptured cavity and seven were within 5 mm proximal or distal to the plaque rupture. Morphologic changes during follow-up, including new plaque ruptures and changes in the attenuated plaque frequency and distribution, were not accompanied by either serious lumen compromise or clinical events.


CONCLUSIONS
Serial IVUS analysis demonstrated that the morphology of unstable plaques within untreated segments in STEMI patients treated with optimal systemic therapies markedly changed during the 13-month follow-up period, without lumen compromise or clinical events at the 3-year follow-up.
aClinical Trials Center, Cardiovascular Research Foundation bDivision of Cardiology, Columbia University Medical Center cZena and Michael A. Weiner Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York dYale Cardiovascular Clinical Research Program, Yale University School of Medicine, New Haven, Connecticut eLeBauer Cardiovascular Research Foundation/Cone Health, Greensboro, North Carolina fMaine Medical Center, Portland, Maine, USA gHelios Amper-Klinikum, Dachau, Germany hOspedale Papa Giovanni XXIII, Bergamo, Italy.
Cristiano F
CF
Souza
Hiroshi
H
Doi
Gary S
GS
Mintz
Alexandra J
AJ
Lansky
Bernhard
B
Witzenbichler
Giulio
G
Guagliumi
Bruce R
BR
Brodie
Mirle A
MA
Kellett
Ke
K
Xu
Roxana
R
Mehran
Gregg W
GW
Stone
Akiko
A
Maehara
D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000628:therapy*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000628:therapy*; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation; D058226:Plaque, Atherosclerotic; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D012422:Rupture, Spontaneous; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D014945:Wound Healing
D010975:Platelet Aggregation Inhibitors