Sadako Motoyama

Computed tomographic angiography characteristics of atherosclerotic plaques subsequently resulting in acute coronary syndrome.

OBJECTIVES In a computed tomographic (CT) angiography study, we identified the characteristics of atherosclerotic lesions that were associated with subsequent development of acute coronary syndrome (ACS). BACKGROUND The CT characteristics of culprit lesions in ACS include positive vessel remodeling (PR) and low-attenuation plaques (LAP). These 2 features have been observed in the lesions that have already resulted in ACS, but their prospective relation to ACS has not been previously described. METHODS In 1,059 patients who underwent CT angiography, atherosclerotic lesions were analyzed for the presence of 2 features: PR and LAP. The remodeling index, and plaque and LAP areas and volumes were calculated. The plaque characteristics of lesions resulting in ACS during the follow-up of 27 +/- 10 months were evaluated. RESULTS Of the 45 patients showing plaques with both PR and LAP (2-feature positive plaques), ACS developed in 10 (22.2%), compared with 1 (3.7%) of the 27 patients with plaques displaying either feature (1-feature positive plaques). In only 4 (0.5%) of the 820 patients with neither PR nor LAP (2-feature negative plaques) did ACS develop. None of the 167 patients with normal angiograms had acute coronary events (p < 0.001). ACS was independently predicted by PR and/or LAP (hazard ratio: 22.8, 95% confidence interval: 6.9 to 75.2, p < 0.001). Among 2- or 1-feature positive segments, those resulting in ACS demonstrated significantly larger remodeling index (126.7 +/- 3.9% vs. 113.4 +/- 1.6%, p = 0.003), plaque volume (134.9 +/- 14.1 mm(3) vs. 57.8 +/- 5.7 mm(3), p < 0.001), LAP volume (20.4 +/- 3.4 mm(3) vs. 1.1 +/- 1.4 mm(3), p < 0.001), and percent LAP/total plaque area (21.4 +/- 3.7 mm(2) vs. 7.7 +/- 1.5 mm(2), p = 0.001) compared with segments not resulting in ACS. CONCLUSIONS The patients demonstrating positively remodeled coronary segments with low-attenuation plaques on CT angiography were at a higher risk of ACS developing over time when compared with patients having lesions without these characteristics.

Arithmetic of vulnerable plaques for noninvasive imaging

Sudden cardiac death and acute myocardial infarction often occur as the first manifestation of coronary artery disease. Otherwise asymptomatic individuals with subclinical atherosclerosis almost always have a classic risk-factor profile and it is essential that they are identified before the occurrence of an acute coronary event. The ability to recognize such individuals requires the development of strategies that can localize unstable atherosclerotic lesions. Plaques that are vulnerable to rupture demonstrate distinct histological characteristics, including large plaque and necrotic core volumes, extensive remodeling of the vessel at the lesion site, and attenuated fibrous caps. Precise metrics of typical vulnerable atherosclerotic plaque dimensions will need to be defined to facilitate their identification by noninvasive imaging modalities.

Serial Coronary CT Angiography–Verified Changes in Plaque Characteristics as an End Point: Evaluation of Effect of Statin Intervention

OBJECTIVES This study sought to assess, by serial computed tomography angiography (CTA), the effect of statin treatment on coronary plaque morphology. BACKGROUND In addition to the assessment of luminal stenosis, CTA also allows characterization of plaque morphology. Large, positively remodeled plaques with large necrotic cores have been reported as indicators of plaque instability. METHODS CTA was performed in 32 patients (26 men, ages 64.3 +/- 8.5 years). Of these, 24 received fluvastatin after the baseline study; 8 subjects who refused statin treatment were followed as the control subjects. Serial imaging was performed after a median interval of 12 months. All vessels were examined in every subject, and a 10-mm-long segment was identified for comparison before and after intervention. Total plaque volume, low attenuation plaque (LAP) volume, lumen volume, and remodeling index were calculated. RESULTS In the statin-treated patients, the total plaque volume (92.3 +/- 37.7 vs. 76.4 +/- 26.5 mm(3), p < 0.01) and LAP volume (4.9 +/- 7.8 vs. 1.3 +/- 2.3 mm(3), p = 0.01) were significantly reduced over time; however, there was no change in the lumen volume (63.9 +/- 25.3 vs. 65.2 +/- 26.2 mm(3), p = 0.59). On the other hand, no change was observed in the CTA characteristics in the control subjects, including total plaque volume (94.4 +/- 21.2 vs. 98.4 +/- 28.6 mm(3), p = 0.48), LAP volume (2.1 +/- 3.0 vs. 2.3 +/- 3.6 mm(3), p = 0.91), and lumen volume (80.5 +/- 20.7 vs. 75.0 +/- 16.3 mm(3), p = 0.26). The plaque volume change (-15.9 +/- 22.2 vs. 4.0 +/- 14.0 mm(3), p = 0.01) and LAP volume change (-3.7 +/- 7.0 vs. 0.2 +/- 1.5 mm(3), p < 0.01) were significantly greater in the statin than the control group. The lumen volume (1.3 +/- 15.6 vs. -5.5 +/- 13.1 mm(3), p = 0.24) and remodeling index (-2.4 +/- 6.8% vs. -0.3 +/- 6.5%, p = 0.53) did not show the significant differences between the 2 groups. The decrease in the plaque volume was due to reduction in the LAP volume (R = 0.83, p < 0.01), and was not related to any changes in the lumen volume (R = 0.21, p = 0.24). CONCLUSIONS This preliminary study suggests that serial CTA evaluation of coronary plaques allows for the assessment of interval change in the plaque morphology. Statin treatment results in decreases in the plaque and necrotic core volume. The features known to be associated with plaque instability.

Original ResearchSerial Coronary CT Angiography–Verified Changes in Plaque Characteristics as an End Point: Evaluation of Effect of Statin Intervention

OBJECTIVES This study sought to assess, by serial computed tomography angiography (CTA), the effect of statin treatment on coronary plaque morphology. BACKGROUND In addition to the assessment of luminal stenosis, CTA also allows characterization of plaque morphology. Large, positively remodeled plaques with large necrotic cores have been reported as indicators of plaque instability. METHODS CTA was performed in 32 patients (26 men, ages 64.3 +/- 8.5 years). Of these, 24 received fluvastatin after the baseline study; 8 subjects who refused statin treatment were followed as the control subjects. Serial imaging was performed after a median interval of 12 months. All vessels were examined in every subject, and a 10-mm-long segment was identified for comparison before and after intervention. Total plaque volume, low attenuation plaque (LAP) volume, lumen volume, and remodeling index were calculated. RESULTS In the statin-treated patients, the total plaque volume (92.3 +/- 37.7 vs. 76.4 +/- 26.5 mm(3), p < 0.01) and LAP volume (4.9 +/- 7.8 vs. 1.3 +/- 2.3 mm(3), p = 0.01) were significantly reduced over time; however, there was no change in the lumen volume (63.9 +/- 25.3 vs. 65.2 +/- 26.2 mm(3), p = 0.59). On the other hand, no change was observed in the CTA characteristics in the control subjects, including total plaque volume (94.4 +/- 21.2 vs. 98.4 +/- 28.6 mm(3), p = 0.48), LAP volume (2.1 +/- 3.0 vs. 2.3 +/- 3.6 mm(3), p = 0.91), and lumen volume (80.5 +/- 20.7 vs. 75.0 +/- 16.3 mm(3), p = 0.26). The plaque volume change (-15.9 +/- 22.2 vs. 4.0 +/- 14.0 mm(3), p = 0.01) and LAP volume change (-3.7 +/- 7.0 vs. 0.2 +/- 1.5 mm(3), p < 0.01) were significantly greater in the statin than the control group. The lumen volume (1.3 +/- 15.6 vs. -5.5 +/- 13.1 mm(3), p = 0.24) and remodeling index (-2.4 +/- 6.8% vs. -0.3 +/- 6.5%, p = 0.53) did not show the significant differences between the 2 groups. The decrease in the plaque volume was due to reduction in the LAP volume (R = 0.83, p < 0.01), and was not related to any changes in the lumen volume (R = 0.21, p = 0.24). CONCLUSIONS This preliminary study suggests that serial CTA evaluation of coronary plaques allows for the assessment of interval change in the plaque morphology. Statin treatment results in decreases in the plaque and necrotic core volume. The features known to be associated with plaque instability.

Noninvasive Coronary Angiography With a Prototype 256-Row Area Detector Computed Tomography System Comparison With Conventional Invasive Coronary Angiography

To the Editor: Since the initial reports describing the usefulness of computed tomography angiography (CTA) with 4-row multislice compute tomography (MSCT) for the examination of the coronary arteries, the number of detector rows has been further increased. Now, 256-row area detector CT (256-row CT

Multimodality Intravascular Imaging to Predict Periprocedural Myocardial Infarction During Percutaneous Coronary Intervention.

OBJECTIVES The aim of this study is to compare the relative merits of optical coherence tomography (OCT), intravascular ultrasound (IVUS), and near infrared spectroscopy (NIRS) in patients with coronary artery disease for the prediction of periprocedural myocardial infarction (MI). BACKGROUND Although several individual intravascular imaging modalities have been employed to predict periprocedural MI, it is unclear which of the imaging tools would best allow prediction of this complication. METHODS We retrospectively analyzed 110 patients who underwent OCT, IVUS, and NIRS. Periprocedural MI was defined as a post-procedural cardiac troponin I (cTnI) elevation above 3× the upper limit of normal; analysis was also performed for cTnI ≥5× the upper limit of normal. RESULTS cTnI ≥3× was observed in 10 patients (9%) and 8 patients had cTnI ≥5×. By OCT, minimum cap thickness was significantly lower (55 vs. 90 μm, p < 0.01), and the plaque burden by IVUS (84 ± 9% vs. 77 ± 8%, p < 0.01) and maximum 4-mm lipid core burden index by NIRS (556 vs. 339, p < 0.01) were greater in the cTnI ≥3× group. Multivariate logistic regression analysis identified cap thickness as the only independent predictor for cTnI ≥3× the upper limit of normal (odds ratio [OR]: 0.90, p = 0.02) or cTnI ≥5× (OR: 0.91, p = 0.04). If OCT findings were excluded from the analysis, plaque burden (OR: 1.13, p = 0.045) and maximum 4-mm lipid core burden index (OR: 1.003, p = 0.037) emerged to be the independent predictors. CONCLUSIONS OCT-based fibrous cap thickness is the most important predictor of periprocedural MI. In the absence of information about cap thickness, NIRS lipid core or IVUS plaque burden best determined the likelihood of the periprocedural event.

Circulating high-mobility group box 1 and cardiovascular mortality in unstable angina and non-ST-segment elevation myocardial infarction

OBJECTIVE High-mobility group box 1 (HMGB1) is a damage-associated molecular pattern molecule, which suggests a potential role of this protein in the pathophysiology of acute coronary syndrome (ACS). Circulating HMGB1 has been shown to be independently associated with cardiac mortality in ST-segment elevation myocardial infarction. However, its prognostic value remains unclear in unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI). METHODS HMGB1, high-sensitivity C-reactive protein (hsCRP), cardiac troponin I and B-type natriuretic peptide concentrations were measured on admission in 258 consecutive patients (mean age of 67 years) hospitalized for UA/NSTEMI within 24h (mean, 7.4h) of the onset of chest symptoms. RESULTS A total of 38 (14.7%) cardiovascular deaths, including 10 in-hospital deaths, occurred during a median follow-up period of 49 months after admission. In a stepwise Cox regression analysis including 19 well-known clinical predictors of ACS, HMGB1 [relative risk (RR) 3.24 per 10-fold increment; P = 0.0003], cardiac troponin I (RR 1.83 per 10-fold increment, P = 0.0007), Killip class>1 (RR 4.67, P = 0.0001) and age (RR 1.05 per 1-year increment, P = 0.03), but not hsCRP, were independently associated with cardiovascular mortality. In-hospital and cardiovascular mortality rates were higher in patients with increased HMGB1 (≥ 2.4 ng/mL of median value) than those without increased HMGB1 (6.3% vs. 1.5%, P = 0.04; and 23% vs. 6.9%, P = 0.0003). CONCLUSION Circulating concentration of HMGB1 on admission may be a potential and independent predictor of cardiovascular mortality in patients hospitalized for UA/NSTEMI within 24h of onset.

Optical coherence tomography assessment of the mechanistic effects of rotational and orbital atherectomy in severely calcified coronary lesions

This study sought to assess the mechanistic effect of rotational atherectomy (RA) and orbital atherectomy (OA) on heavily calcified coronary lesions and subsequent stent placement using optical coherence tomography (OCT).

Characteristics of plaque progression detected by serial coronary computed tomography angiography

We previously reported that serial coronary computed tomography angiography (CTA) had a potential to evaluate the interval change of plaque morphology of coronary arteries. The aim of this study was to evaluate variables associated with the plaque progression by serial CTA. We included 148 patients (age 66.3 ± 9.8 years, male 81.1 %, median scan interval 12 months) with coronary artery disease undergoing serial CTA. Each coronary artery was compared visually between baseline and follow-up CTA to detect plaque progression. Baseline characteristics between progression and nonprogression patients did not demonstrate any significant differences. Logistic analysis revealed that only low-density lipoprotein cholesterol (LDL-C) ≥100 mg/dl at follow-up was associated with plaque progression (odds ratio 2.59, 95 % confidence interval 1.12–6.34, P = 0.0263). Cutoff value of LDL-C for plaque progression at follow-up was 103.0 mg/dl based on receiver-operator characteristic curves analyses. Of the 36 progressive lesions in 32 patients, plaque composition at baseline included 13 lesions (36.1 %) of noncalcified plaque, 1 lesion (2.8 %) of calcified plaque, 12 lesions (33.3 %) of partially calcified plaque, and the remaining 10 lesions (27.8 %) had no plaque at baseline and revealed de novo plaques at follow-up. There were 9 lesions (25 %) with high-risk plaque (HRP) characteristics at baseline and 18 lesions (50 %) with HRP at follow-up. Plaque progression of coronary arteries by serial CTA was associated with LDL-C ≥100 mg/dl at follow-up regardless of baseline LDL-C level. There was no specific finding to predict plaque progression on the baseline plaque characteristics.

Two cases with past Kawasaki disease developing acute myocardial infarction in their thirties, despite being regarded as at low risk for coronary events

Two patients after Kawasaki disease (KD) developed acute myocardial infarction in their thirties, though coronary artery follow-up were deemed unnecessary because of apparently angiographic normal coronary arteries in their children more than 1-year after acute KD. Angiographic findings of apparently normal coronary arteries in the late period after acute KD are possible to mislead their prognoses. It should be recognized that coronary aneurysms can often regress in the late period. There is ongoing controversy about the therapeutic strategy in patients whose coronary aneurysms regressed within several years after acute KD. Coronary computed tomography angiography and flow-mediated dilatation might be useful for the detection of mild sequelae of KD non-invasively.