Plaque Characterization by CTA and Acute Coronary Events
Plaque Characterization by CTA and Acute Coronary Events
Background Coronary computed tomography angiography (CTA)-verified positive remodeling and low attenuation plaques are considered morphological characteristics of high-risk plaque (HRP) and predict short-term risk of acute coronary syndrome (ACS).
Objectives This study evaluated whether plaque characteristics by CTA predict mid-term likelihood of ACS.
Methods The presence of HRP and significant stenosis (SS) of ≥70% were evaluated in 3,158 patients undergoing CTA. Serial CTA was performed in 449 patients, and plaque progression (PP) was evaluated. Outcomes (fatal and nonfatal ACS) were recorded during follow-up (mean 3.9 ± 2.4 years).
Results ACS occurred in 88 (2.8%) patients: 48 (16.3%) of 294 HRP(+) and 40 (1.4%) of 2,864 HRP(−) patients. ACS was also significantly more frequent in SS(+) (36 of 659; 5.5%) than SS(−) patients (52 of 2,499; 2.1%). HRP(+)/SS(+) (19%) and HRP(+)/SS(−) (15%) had higher rates of ACS compared with no-plaque patients (0.6%). Although ACS incidence was relatively low in HRP(−) patients, the cumulative number of patients with ACS developing from HRP(−) lesions (n = 43) was similar to ACS patients with HRP(+) lesions (n = 45). In patients with serial CTA, PP also was an independent predictor of ACS, with HRP (27%; p < 0.0001) and without HRP (10%) compared with HRP(−)/PP(−) patients (0.3%).
Conclusions CTA-verified HRP was an independent predictor of ACS. However, the cumulative number of ACS patients with HRP(−) was similar to patients with HRP(+). Additionally, plaque progression detected by serial CTA was an independent predictor of ACS.
Coronary computed tomography angiography (CTA) allows noninvasive assessment of luminal stenosis, as well as plaque morphology. Several reports have confirmed CTA's diagnostic accuracy for identifying significantly obstructive disease, and the severity of such stenosis was also predictive of major adverse cardiac events. Additionally, lesions predictive of major adverse cardiac events demonstrate positive remodeling (PR) and low attenuation plaque (LAP). Noncalcified plaques with ≤30 Hounsfield unit (HU) densities identified by CTA correlate closely with intravascular ultrasound (IVUS)-verified necrotic cores in coronary atherosclerotic plaques. Although the presence of PR and LAP was associated with the development of acute coronary syndrome (ACS) during 2-year follow-up in our previous study, the mid-term prognosis on the basis of CTA findings has not been reported. In the present study, we extended the follow-up period to investigate the relationship between CTA-verified high-risk plaque (HRP) and the incidence of ACS in mid-term follow-up. In patients with serial CTA, the association between plaque progression (PP) and ACS was also evaluated.
Abstract and Introduction
Abstract
Background Coronary computed tomography angiography (CTA)-verified positive remodeling and low attenuation plaques are considered morphological characteristics of high-risk plaque (HRP) and predict short-term risk of acute coronary syndrome (ACS).
Objectives This study evaluated whether plaque characteristics by CTA predict mid-term likelihood of ACS.
Methods The presence of HRP and significant stenosis (SS) of ≥70% were evaluated in 3,158 patients undergoing CTA. Serial CTA was performed in 449 patients, and plaque progression (PP) was evaluated. Outcomes (fatal and nonfatal ACS) were recorded during follow-up (mean 3.9 ± 2.4 years).
Results ACS occurred in 88 (2.8%) patients: 48 (16.3%) of 294 HRP(+) and 40 (1.4%) of 2,864 HRP(−) patients. ACS was also significantly more frequent in SS(+) (36 of 659; 5.5%) than SS(−) patients (52 of 2,499; 2.1%). HRP(+)/SS(+) (19%) and HRP(+)/SS(−) (15%) had higher rates of ACS compared with no-plaque patients (0.6%). Although ACS incidence was relatively low in HRP(−) patients, the cumulative number of patients with ACS developing from HRP(−) lesions (n = 43) was similar to ACS patients with HRP(+) lesions (n = 45). In patients with serial CTA, PP also was an independent predictor of ACS, with HRP (27%; p < 0.0001) and without HRP (10%) compared with HRP(−)/PP(−) patients (0.3%).
Conclusions CTA-verified HRP was an independent predictor of ACS. However, the cumulative number of ACS patients with HRP(−) was similar to patients with HRP(+). Additionally, plaque progression detected by serial CTA was an independent predictor of ACS.
Introduction
Coronary computed tomography angiography (CTA) allows noninvasive assessment of luminal stenosis, as well as plaque morphology. Several reports have confirmed CTA's diagnostic accuracy for identifying significantly obstructive disease, and the severity of such stenosis was also predictive of major adverse cardiac events. Additionally, lesions predictive of major adverse cardiac events demonstrate positive remodeling (PR) and low attenuation plaque (LAP). Noncalcified plaques with ≤30 Hounsfield unit (HU) densities identified by CTA correlate closely with intravascular ultrasound (IVUS)-verified necrotic cores in coronary atherosclerotic plaques. Although the presence of PR and LAP was associated with the development of acute coronary syndrome (ACS) during 2-year follow-up in our previous study, the mid-term prognosis on the basis of CTA findings has not been reported. In the present study, we extended the follow-up period to investigate the relationship between CTA-verified high-risk plaque (HRP) and the incidence of ACS in mid-term follow-up. In patients with serial CTA, the association between plaque progression (PP) and ACS was also evaluated.