Identification of parameters associated with plaque erosion in STEMI and NSTE-ACS
Clinical and Laboratory Predictors for Plaque Erosion in Patients With Acute Coronary Syndromes
Introduction and methods
In about 25-40% of acute coronary syndromes (ACS), plaque erosion is reported to be responsible [1-3]. In all but low-risk subgroups, early invasive strategy is recommended [4,5], generally leading to implantation of coronary stents.
Recent studies suggest that ACS patients with plaque erosion may be treated conservatively without stenting [6-8]. Plaque erosion can be made visible by intracoronary optical coherence tomography (OCT). Demographic characteristics that may be specific for patients with plaque erosion, which may allow avoidance of invasive procedures, are unknown. This study therefore aimed to identify predictors for plaque erosion in patients with ACS.
This is a study in a new longitudinal international registry that included consecutive patients with ACS who had OCT imaging of the culprit lesion. ACS was considered as ST-segment-elevation myocardial infarction (STEMI), NSTE-ACS (including NSTEMI and unstable angina pectoris). 1241 Patients were included in the final cross-sectional analysis. Based on the OCT analysis, plaque type in the culprit lesion was categorized as:
- plaque rupture: presence of fibrous cap discontinuity with a communication between the lumen and the inner core of plaque or with a cavity formation within the plaque,
- plaque erosion : presence of the attached thrombus overlying an intact and visualized plaque, luminal surface irregularity at the culprit lesion in absence of thrombus, or attenuation of the underlying plaque by thrombus without superficial lipid or calcification immediately proximal or distal to the site of thrombus,
- calcified plaque : presence of superficial substantive calcium at the culprit site without evidence of ruptured lipid plaque.
- 607 Patients (48.9%) had plaque rupture, 477 (38.4%) plaque erosion, and 157 (12.7%) calcified plaque. Among 648 STEMI patients, 59.4% had plaque rupture and 29.8% plaque erosion. In 593 NSTE-ACS patients, 37.4% had plaque rupture and 47.9% had erosion.
The following predictors of plaque erosion were identified:
- Age < 68 years: OR: 1.56, 95%CI: 1.16-2.09, P=0.003
- Anterior ischemia: OR: 1.41, 95%CI: 1.06-1.86, P=0.02
- No diabetes mellitus: OR: 1.47, 95%CI: 1.08-2.01, P=0.01
- Hemoglobin >15.0 g/dL: OR: 1.48, 95%CI: 1.09-2.01, P=0.01
- Normal renal function: OR: 1.97, 95%CI: 1.32-2.95, P=0.0009
When all five predicting parameters are present in NSTE-ACS patients, probability of plaque erosion increased to 73.1%, with OR: 3.40 (95%CI: 1.39-8.29, P=0.007).
This international study in over 1200 patients with STEMI or NSTE-ACS, found that plaque erosion was more frequent in NSTE-ACS than in STEMI. Age <68 years, anterior ischemia, no diabetes, hemoglobin >15.0 g/dL and normal renal function were associated with plaque erosion. When all five aspects are present simultaneously, the probability of plaque erosion increases up to 73%. These data suggest that plaque erosion has a distinct pathobiology compared with plaque rupture. Use of the identified parameters needs to be evaluated in large-scale prospective clinical studies.