Tissue characteristics of non-culprit plaque in patients with acute coronary syndrome vs. stable angina: a color-coded intravascular ultrasound study

Characterizing Nonculprit Lesions and Perivascular Adipose Tissue of Patients Following Acute Myocardial Infarction Using Coronary Computed Tomography Angiography: A Comparative Study

BACKGROUND

The comparison of coronary computed tomography angiography plaques and perivascular adipose tissue (PVAT) between patients with acute myocardial infarction (AMI) posttreatment and patients with stable coronary artery disease is poorly understood. Our objective was to evaluate the differences in coronary computed tomography angiography-quantified plaque and PVAT characteristics in patients post-AMI and identify signs of residual inflammation.

METHODS AND RESULTS

We analyzed 205 patients (age, 59.77±9.24 years; 92.20% men) with AMI ≤1 month and matched them with 205 patients with stable coronary artery disease (age, 60.52±10.04 years; 90.24% men) based on age, sex, and cardiovascular risk factors. Coronary computed tomography angiography scans were assessed for nonculprit plaque and vessel characteristics, plaque volumes by composition, high-risk plaques, and PVAT mean attenuation. Both patient groups exhibited similar noncalcified plaque volumes (383.35±313.23 versus 378.63±426.25 mm3, P=0.899). However, multivariable analysis revealed that patients post-AMI had a greater patient-wise noncalcified plaque volume ratio (estimate, 0.089 [95% CI, 0.053-0.125], P<0.001), largely attributed to a higher fibrofatty and necrotic core volume ratio, along with higher peri-lesion PVAT mean attenuation (estimate, 3.968 [95% CI, 2.556-5.379], P<0.001). When adjusted for vessel length, patients post-AMI had more high-risk plaques (estimate, 0.417 [95% CI, 0.298-0.536], P<0.001) per patient.

CONCLUSIONS

Patients post-AMI displayed heightened noncalcified plaque components, largely due to fibrofatty and necrotic core content, more high-risk plaques, and increased PVAT mean attenuation on a per-patient level, highlighting the necessity for refined risk assessment in patients with AMI after treatment.

Optical Coherence Tomography of Coronary Plaque Progression and Destabilization: JACC Focus Seminar Part 3/3

The development of optical coherence tomography (OCT) has revolutionized our understanding of coronary artery disease. In vivo OCT research has paralleled with advances in computational fluid dynamics, providing additional insights in the various hemodynamic factors influencing plaque growth and stability. Recent OCT studies introduced a new concept of plaque healing in relation to clinical presentation. In addition to known mechanisms of acute coronary syndromes such as plaque rupture and plaque erosion, a new classification of calcified plaque was recently reported. This review will focus on important new insights that OCT has provided in recent years into coronary plaque development, progression, and destabilization, with a focus on the role of local hemodynamics and endothelial shear stress, the layered plaque (signature of previous subclinical plaque destabilization and healing), and the calcified culprit plaque.

Cardio-ankle vascular index is associated with coronary plaque composition assessed with iMAP-intravascular ultrasound in patients with coronary artery disease

BACKGROUND

The cardio-ankle vascular index (CAVI) is an indicator of arterial stiffness and has been reported to be associated with the severity of coronary artery disease and cardiovascular events. However, whether CAVI can predict the composition of coronary plaques remains unclear.

METHODS

We enrolled 208 patients who underwent percutaneous coronary intervention (PCI) for culprit lesions evaluated with iMAP-intravascular ultrasound (IVUS), a radiofrequency imaging system for characterizing tissues. iMAP-IVUS classified the culprit plaque composition as fibrotic, lipidic, necrotic, or calcified, and the respective absolute volumes [fibrotic volume (FV), lipidic volume (LV), necrotic volume NV, and calcified volume] and their ratios (%) within the total plaque volume were calculated. A plaque with a median %NV of ≥ 33.2% was defined as a larger NV (LNV) plaque. We measured CAVI and divided the patients into two groups according to CAVI ≥8 (high CAVI, n = 164) or <8 (low CAVI, n = 44).

RESULTS

Culprit plaques had significantly greater absolute NV (p = 0.016), %NV (p = 0.01), and smaller %FV (p = 0.02) in patients with high CAVI than in those with low CAVI. Patients with high CAVI had a higher prevalence of LNV plaques in culprit lesions than those with low CAVI (54% vs. 34%, p = 0.026). CAVI correlated significantly and positively with absolute NV, LV, and negatively with %FV. In logistic regression analysis after adjustment for the classic coronary risk factors and possible variables associated with vulnerable plaques, high CAVI had an independent and significant association with the presence of LNV plaques (OR, 3.37; 95% CI, 1.45-7.79; p = 0.0032).

CONCLUSIONS

A high CAVI is associated with the composition of coronary culprit plaques, particularly increased amount of necrotic tissue, in patients with coronary artery disease undergoing PCI .

Characteristics of non-culprit plaques in acute coronary syndrome patients with layered culprit plaque

AIMS

Layered plaques represent signs of previous plaque destabilization. A recent study showed that acute coronary syndrome (ACS) patients with layered culprit plaque have more vulnerability at the culprit lesion and systemic inflammation. We aimed to compare the characteristics of non-culprit plaques between patients with or without layered plaque at the culprit lesion. We also evaluated the characteristics of layered non-culprit plaques, irrespective of culprit plaque phenotype.

METHODS AND RESULTS

We studied ACS patients who had undergone pre-intervention optical coherence tomography (OCT) imaging. The number of non-culprit lesions was evaluated on coronary angiogram and morphological characteristics of plaques were studied by OCT. In 349 patients, 99 (28.4%) had layered culprit plaque. The number of non-culprit plaques in patients with or without layered culprit plaque was similar (3.2 ± 0.8 and 2.8 ± 0.8, P = 0.23). Among 465 non-culprit plaques, 145 from patients with layered culprit plaque showed a higher prevalence of macrophage infiltration (71.0% vs. 60.9%, P = 0.050). When analysed irrespective of culprit plaque phenotype, layered non-culprit plaques showed higher prevalence of lipid (93.3% vs. 86.0%, P = 0.028), thin cap fibroatheroma (29.7% vs. 13.7%, P < 0.001), and macrophage infiltration (82.4% vs. 54.0%, P < 0.001) than non-layered plaques. Plaques with layered phenotype at both culprit and non-culprit lesions had the highest vulnerability.

CONCLUSION

In ACS patients, those with layered phenotype at the culprit lesion demonstrated greater macrophage infiltration at the non-culprit sites. Layered plaque at the non-culprit lesions was associated with more features of plaque vulnerability, particularly when the culprit lesion also had a layered pattern.

Healed Plaques in Patients With Stable Angina Pectoris

OBJECTIVE

Healed plaques, signs of previous plaque destabilization, are frequently found in the coronary arteries. Healed plaques can now be diagnosed in living patients. We investigated the prevalence, angiographic, and optical coherence tomography features of healed plaques in patients with stable angina pectoris. Approach and Results: Patients with stable angina pectoris who had undergone optical coherence tomography imaging were included. Healed plaques were defined as plaques with one or more signal-rich layers of different optical density. Patients were divided into 2 groups based on layered or nonlayered phenotype at the culprit lesion. Among 163 patients, 87 (53.4%) had layered culprit plaque. Patients with layered culprit plaque had more multivessel disease (62.1% versus 44.7%, P=0.027) and more angiographically complex culprit lesions (64.4% versus 35.5%, P<0.001). Layered culprit plaques had higher prevalence of lipid plaque (83.9% versus 64.5%, P=0.004), macrophage infiltration (58.6% versus 35.5%, P=0.003), calcifications (78.2% versus 63.2%, P=0.035), and thrombus (28.7% versus 14.5%, P=0.029). Lipid index (P=0.001) and percent area stenosis (P=0.015) were greater in the layered group. The number of nonculprit plaques, evaluated using coronary angiograms, tended to be greater in patients with layered culprit plaque (4.2±2.5 versus 3.5±2.1, P=0.053). Nonculprit plaques in patients with layered culprit lesion had higher prevalence of layered pattern (P=0.002) and lipid phenotype (P=0.005). Lipid index (P=0.013) and percent area stenosis (P=0.002) were also greater in this group.

CONCLUSIONS

In patients with stable angina pectoris, healed culprit plaques are common and have more features of vulnerability and advanced atherosclerosis both at culprit and nonculprit lesions.

High shear stress on the coronary arterial wall is related to computed tomography-derived high-risk plaque: a three-dimensional computed tomography and color-coded tissue-characterizing intravascular ultrasonography study

Low wall shear stress (WSS) is associated with plaque formation. However, the relationship between WSS and coronary plaque vulnerability remains unclear. Therefore, this study aimed to clarify the in vivo relationship between luminal WSS derived from three-dimensional (3D) computed tomography (CT) and plaque vulnerability within the coronary artery. Forty-three consecutive patients with ischemic heart disease and coronary stenotic lesions were enrolled and underwent coronary angiography and color-coded intravascular ultrasonography (iMap™) followed by multi-slice coronary CT angiography. CT-derived high-risk plaque was defined by specific CT characteristics, including low CT intensity (< 30 HU) and positive remodeling. The Student's t test, Mann-Whitney U test, χ² test, repeated measures analysis of variance, and logistic and multiple regression were used for statistical analyses. CT-derived high-risk plaque (n = 15) had higher values of maximum and average shear stress than CT-derived stable plaque (474 ± 453 vs. 158 ± 138 Pa, p = 0.018; 4.2 ± 3.1 vs. 1.6 ± 1.2 Pa, p = 0.007, respectively). Compared with patients with CT-derived stable plaque, those with CT-derived high-risk plaque had a higher prevalence of necrotic and lipidic characteristics (44 ± 13 vs. 31 ± 11%, p = 0.001) based on iMap™. Multivariate logistic regression analysis showed that the average WSS and necrotic plus lipidic content were independent determinants of CT-derived high-risk plaque (average WSS: odds ratio 2.996, p = 0.014; necrotic plus lipidic content: odds ratio 1.306, p = 0.036). Our findings suggested that CT-derived high-risk plaque may coexist with high shear stress on the plaque surface.

Modified balloon-stent kissing technique avoid side-branch compromise for simple true bifurcation lesions

Background

Coronary bifurcation remains one of the most challenging lesion subsets in interventinal cardiology. Provisional stenting (PS) is the dominate technique for bifurcation lesions, but the key problem is the deterioration of side branch. Balloon-stent kissing technique (BSKT) as a new systematic approach which is based on modified jailed balloon technique is applied to improve the procedure success. In our center, we proposed a modified balloon-stent kissing technique(M-BSKT), which routine usage of proximal optimizing technique (POT) after rewiring was added as an optimization step to BSKT. Thus, whether M-BSKT for addressing simple true coronary bifurcation lesions can provide more benefits in intra-operation effect and long term outcomes is still unknown.

Methods

A cohort of 120 consecutive patients underwent Percutaneous Coronary Intervention (PCI) with simple true coronary bifurcation lesions satisfied the criteria were included in this retrospective, single-center registry. To assemble a cohort with similar baseline characteristics, a 1:1 propensity-matched score was used. The primary outcomes were the rate of device and procedural success, the situation of side branch (SB) after main vessel (MV) inflation and the complications during intra-operative. The secondary outcomes were the clinical prognosis at 12 months such as rehospitalization for unstable angina and MACEs.

Results

Before propensity matching, there were no significant differences in primary and secondary outcomes between two groups. After propensity-matched was used, 68 patients with similar propensity scores were included. At immediate procedural, M-BSKT was associated with a lower risk of SB deterioration and the application of final kissing balloon inflation (FKBI)[P = 0.036]. For ACS patients, besides the significant differences of immediate SB deterioration [P = 0.014] and FKBI application [P = 0.033], the incidence of TIMI flow< 3 in the PS was statistically significant higher than M-BSKT [P= 0.042]. The prognosis at 12 months such as rehospitalization for unstable angina and MACEs were similar for two groups [P = 0.613].

Conclusion

These observations prove that the M-BSKT enables side branch to be better protected in simple true bifurcation lesions, by a narrow margin. It may improve the angiographic outcomes about side branch deterioration and final kissing balloon performing compared with PS, especially in ACS patients. However, long-term clinical outcomes did not differ between patients treated for M-BSKT and PS at 12 months.

Outcome of staged percutaneous coronary intervention within two weeks from admission in patients with ST-segment elevation myocardial infarction with multivessel disease

BACKGROUND

The optimum timing of revascularization strategy for stenoses in nonculprit vessels in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD) remains unclear. At present, there is no evidence investigating the outcome of staged percutaneous coronary intervention (PCI) within two weeks from admission among STEMI patients with MVD.

METHODS

A total of 210 STEMI patients with MVD who underwent primary PCI were analyzed. We compared the all-cause mortality and major adverse cardiovascular events (MACE) (cardiovascular death, myocardial infarction, heart failure, unstable angina, and stroke) with median follow-up of 1200 days among the patients who underwent staged PCI within two weeks from admission (staged PCI ≤2 W) (n = 75), staged PCI after two weeks from admission (staged PCI >2 W) (n = 37) and culprit-only PCI (n = 98) in patients with STEMI and MVD.

RESULTS

The staged PCI ≤2 W showed lower all-cause mortality than culprit-only PCI (4.0 vs 29.6%, log-rank P = 0.001), and lower incidence of MACE than the staged PCI >2 W group (1.3 vs 18.9%, log-rank P = 0.001) and culprit-only PCI group (1.3 vs 22.5%, log-rank P = 0.001). In the multivariable Cox regression analysis, the staged PCI ≤2 W was a predictor of lower all-cause mortality (hazard ratio [HR], 0.176; 95% confidence interval [CI], 0.049-0.630; P = 0.008) and lower incidence of MACE (HR, 0.068; 95% CI, 0.009-0.533; P = 0.011), but staged PCI >2 W was not.

CONCLUSION

In conclusion, staged PCI within two weeks after admission showed more favorable outcomes compared with staged PCI after two weeks from admission or culprit-only PCI in STEMI patients with MVD.

Homocysteine is associated with the progression of non-culprit coronary lesions in elderly acute coronary syndrome patients after percutaneous coronary intervention

BACKGROUND

The influence of homocysteine (Hcy) on the migration and proliferation of vascular smooth muscle cells has been well established. However, the impact of Hcy levels on the progression of non-culprit coronary lesions (NCCLs) is controversial. This study aims to evaluate whether the plasma level of Hcy is related to the progression of NCCLs after percutaneous coronary stent implantation in elderly patients with acute coronary syndrome (ACS).

METHODS

A total of 223 elderly patients (≥ 65 years old) with ACS undergoing stent implantation and follow-up coronary angiography were enrolled. Laboratory determination comprised of blood sample evaluation for Hcy was carried out before baseline coronary intervention. The patients were classified into two groups according to the blood Hcy tertiles (≥ 15 mmol/L or < 15 mmol/L). Patients were followed up for 12.2 months. NCCL progression was assessed by three-dimensional quantitative coronary angiography.

RESULTS

A significantly higher ratio of NCCL progression was observed in the group with baseline Hcy concentrations above 15 mmol/L compared to the group with concentrations below 15 mmol/L (41/127, 32.3% vs. 14/96, 14.6%, P = 0.002). Multivariate Cox regression analysis showed that Hcy and diabetes mellitus were independent risk factors for NCCL progression. The crude hazard ratio (HR) of NCCL progression for Hcy level was 1.056 (95% CI: 1.01-1.104, P = 0.015). The adjusted HR of NCCL progression for Hcy level was 1.024 (95% CI: 1.007-1.042, P = 0.007). The adjusted HR of NCCL progression for diabetes mellitus was 1.992 (95% CI: 1.15-3.44, P = 0.013).

CONCLUSIONS

Hcy is an independent risk factor for NCCL progression after 12 months of follow-up in elderly patients with ACS who has undergone percutaneous coronary stenting.