Impact of baseline plaque characteristic on the development of neoatherosclerosis in the very late phase after stenting

Impact of baseline yellow plaque assessed by coronary angioscopy on vascular response after stent implantation

BACKGROUND

The relationship between baseline yellow plaque (YP) and vascular response after stent implantation has not been fully investigated.

METHODS

This was a sub-analysis of the Collaboration-1 study (multicenter, retrospective, observational study). A total of 88 lesions from 80 patients with chronic coronary syndrome who underwent percutaneous coronary intervention were analyzed. Optical coherence tomography (OCT) and coronary angioscopy (CAS) were serially performed immediately and 11 months after stent implantation. YP was defined as the stented segment with yellow or intensive yellow color assessed by CAS. Neoatherosclerosis was defined as a lipid or calcified neointima assessed by OCT. OCT and CAS findings at 11 months were compared between lesions with baseline YP (YP group) and lesions without baseline YP (Non-YP group).

RESULTS

Baseline YP was detected in 37 lesions (42 %). OCT findings at 11 months showed that the incidence of neoatherosclerosis was significantly higher in the YP group (11 % versus 0 %, p = 0.028) and mean neointimal thickness tended to be lower (104 ± 43 μm versus 120 ± 48 μm, p = 0.098). CAS findings at 11 months demonstrated that the dominant and minimum neointimal coverage grades were significantly lower (p = 0.049 and P = 0.026) and maximum yellow color grade was significantly higher (p < 0.001) in the YP group.

CONCLUSIONS

Baseline YP affected the incidence of neoatherosclerosis as well as poor neointimal coverage at 11 months after stent implantation.

The Residual Lipid-rich Coronary Atheroma behind the Implanted Newer-generation Drug-eluting Stent and Future Stent-related Event's Risks

BACKGROUND

Lipid-rich plaque is an important substrate that causes future coronary events. However, the clinical implications of underlying plaque characteristics in coronary lesions after newer-generation drug-eluting stent (DES) implantation remain unknown.

METHODS

The current study analyzed 445 target lesions after newer-generation DES implantation in 416 patients with CAD (CCS/ACS=264/181) from the REASSURE-NIRS multi-center registry. Near-infrared spectroscopy (NIRS) imaging was used to evaluate maximum lipid core burden index after stent implantation in target lesions (residual maxLCBI_4mm). The primary and secondary outcomes were 3-year lesion-oriented clinical outcomes (LOCO; cardiac death, non-fatal target lesion-related MI, or ischemia-driven TLR) and patient-oriented clinical outcomes (POCO; all-cause death, non-fatal MI, or ischemia-driven unplanned revascularization). Outcomes were compared by residual maxLCBI_4mm tertile.

RESULTS

Median residual maxLCBI_4mm was 183; 16% of lesions had residual maxLCBI_4mm >400. Higher residual maxLCBI_4mm was not associated with a greater likelihood of LOCO or POCO during the observational period (LOCO, log-rank p=0.76; POCO, log-rank p=0.84). Mixed-effects logistic regression demonstrated that residual maxLCBI_4mm does not predict LOCO (odds ratio=1.000, 95% CI=0.997-1.003, p=0.95). There was no significant relationship between residual maxLCBI_4mm and POCO (odds ratio=1.001, 95% CI=0.999-1.002, p=0.30).

CONCLUSIONS

Residual maxLCBI_4mm is not associated with LOCO or POCO in patients with CAD after newer-generation DES implantation. Our findings suggest that NIRS-derived underlying lipid-rich plaque is not associated with the risk of stent-related events and patient-based outcomes in patients with CAD who have received a newer-generation DES.

In Stent Neo-Atherosclerosis: Pathophysiology, Clinical Implications, Prevention, and Therapeutic Approaches

Despite the dramatic improvements of revascularization therapies occurring in the past decades, a relevant percentage of patients treated with percutaneous coronary intervention (PCI) still develops stent failure due to neo-atherosclerosis (NA). This histopathological phenomenon following stent implantation represents the substrate for late in-stent restenosis (ISR) and late stent thrombosis (ST), with a significant impact on patient’s long-term clinical outcomes. This appears even more remarkable in the setting of drug-eluting stent implantation, where the substantial delay in vascular healing because of the released anti-proliferative agents might increase the occurrence of this complication. Since the underlying pathophysiological mechanisms of NA diverge from native atherosclerosis and early ISR, intra-coronary imaging techniques are crucial for its early detection, providing a proper in vivo assessment of both neo-intimal plaque composition and peri-strut structures. Furthermore, different strategies for NA prevention and treatment have been proposed, including tailored pharmacological therapies as well as specific invasive tools. Considering the increasing population undergoing PCI with drug-eluting stents (DES), this review aims to provide an updated overview of the most recent evidence regarding NA, discussing pathophysiology, contemporary intravascular imaging techniques, and well-established and experimental invasive and pharmacological treatment strategies.

Clinical significance of neoatherosclerosis observed at very late phase between 3 and 7 years after coronary stent implantation

BACKGROUND

Clinical significance of neoatherosclerosis (NA) observed at very late phase remains undetermined. We sought to investigate the association between NA observed by optical coherence tomography (OCT) 3-7 years after stenting and subsequent clinical outcomes.

METHODS

We investigated previously implanted stents without stent failure in the institutional OCT database at Tsuchiura Kyodo General Hospital. Qualitative and quantitative OCT analyses were performed. In patient-based analysis, major adverse cardiac events (MACE) included all-cause death, non-fatal myocardial infarction, and clinically driven revascularization. MACE-free survival rate was compared between patients with any stent showing NA (NA group) and those without NA (non-NA group). In stent-based analysis, the stent failure including target-lesion revascularization and stent thrombosis after the belated OCT examination were assessed.

RESULTS

A total of 187 patients with 308 stents undergoing belated OCT examination 3-7 years after implantation were investigated. Median duration from implantation to the belated OCT was 4.8 (3.8-5.8) years and NA was identified in 48 stents (15.6%) in 36 patients (19.3%). In patient-based analysis, during the median of 2.9 (2.1-3.6) years after belated OCT, MACE occurred in 9 patients (25.0%) with at least one stent showing NA (NA group) and 9 patients (6.0%) without NA (non-NA group) (p=0.002). Cox regression analysis revealed that NA was an independent predictor of MACE [hazard ratio (HR) 4.14 (1.58- 10.8), p=0.004]. In stent-based analysis, 7 stent failures were documented (stents with NA 10.0% vs. stents without NA 0.8%, p<0.01). NA was a significant predictor of stent failure [HR 9.17 (1.67- 50.3), p=0.011] at OCT examinations.

CONCLUSIONS

NA observed by OCT 3-7 years after implantation was associated with subsequent worse clinical outcomes in both patient-based and stent-based analysis.

Interobserver variability in assessments of atherosclerotic lesion type via optical frequency domain imaging

BACKGROUND

To date, there have been no data available regarding the diagnostic performance of optical frequency domain imaging (OFDI) for in vivo histological classification of atherosclerotic lesions. This study investigated whether OFDI can be used to diagnose and classify histological atherosclerotic lesions in the coronary artery by ex vivo histological examinations.

METHODS

Three-hundred-fifteen histological cross-sections from 21 autopsy hearts were matched with the OFDI images. Histological cross-sections were classified into six categories: adaptive intimal thickening (AIT), pathological intimal thickening (PIT), fibrous cap atheroma (FA), fibrocalcific plaque (FC), calcified nodule, and healed erosion/rupture. The five observers with different years of experience in the interpretation of OFDI provided a single diagnosis for the OFDI scans of each cross-section according to the aforementioned six histological categories. The diagnostic accuracy and interobserver variability of lesion types for each OFDI observer were determined using histology as the gold standard.

RESULTS

The overall agreement rates between OFDI and histopathologic diagnosis for OFDI observers 1-5 were 81%, 70%, 68%, 61%, and 50% (κ values of 0.75, 0.61, 0.58, 0.49, and 0.36), respectively. Although the diagnostic accuracy of OFDI for detecting AIT and FC was excellent for all five observers, the sensitivity, and positive predictive values of OFDI for detecting PIT and FA were low in proportion to years of experience.

CONCLUSION

The diagnostic accuracy of atherosclerotic tissue properties from OFDI scans correlated with the observers' years of experience, especially when lesions contained lipid components.

Characteristics of recurrent in-stent restenosis after second- and third-generation drug-eluting stent implantation

BACKGROUND

In second- and third-generation drug-eluting stent (DES) era, in-stent restenosis (ISR) is not commonly seen. However, a few patients still need repeat revascularizations for recurrent ISR even after second- and third-generation DES implantation.

METHODS

From January 2012 to March 2017, 2339 lesions underwent second- and third-generation DES (Nobori, Promus Element, Resolute Integrity, Xience, Ultimaster and Synergy) implantation, of which 95 lesions (4.1%) underwent revascularization for first ISR. All lesions were divided into two groups of recurrent ISR group and non-recurrent ISR group. After successful optical coherence tomography (OCT) guided revascularization for all lesions, we investigated characteristics of recurrent ISR, and 2 years follow-up were completed.

RESULTS

The mean age was 70.8 ± 11.7 years, and 73.2% were males. Among 56 DES-ISR lesions which were assessed by OCT, recurrent ISR was seen in 33.9% (N = 19) at 2 years follow-up after revascularization for first ISR. Serum low-density lipoprotein-cholesterol (LDL-C) level was higher in recurrent ISR group compared with non-recurrent ISR group (114.1 ± 53.9 mg/dl vs. 90.9 ± 27.8 mg/dl, P = 0.04) and heterogeneous tissue pattern was more frequently found in recurrent ISR group compared with non-recurrent ISR group (63.2% vs. 27.0%, P = 0.03). Multivariate analysis identified a heterogeneous tissue pattern (odds ratio 3.71; 95% confidence interval 1.09-12.59; P = 0.03) as an independent predictor of recurrent restenosis.

CONCLUSION

Recurrent ISR of second- and third-generation DES was associated with heterogeneous tissue pattern of first ISR, and high LDL-C level was associated with recurrence.

Achilles tendon thickening is associated with higher incidence of adverse cardiovascular event in patients with coronary artery disease

Achilles tendon thickening (ATT) is a marker of high risk for coronary artery disease (CAD). However, the association between the presence of ATT and the incidence of cardiovascular events in patients with CAD is unclear. A total of 406 consecutive patients who underwent percutaneous coronary intervention (PCI) and ATT assessment were analyzed. ATT was defined as the Achilles tendon thickness of 9 mm or more on radiography. The incidence of major adverse cardiovascular events (MACE) at 1-year was compared between patients with ATT and those without ATT. MACE included cardiac death, non-fatal myocardial infarction, stroke, target vessel revascularization (TVR), and non-TVR. ATT was found in 67 patients (16.5%). The incidence of cardiac death (3.2 vs. 0.0%, p = 0.001), TVR (12.7 vs. 4.0%, p = 0.005) and MACE (20.6 vs. 9.6%, p = 0.011) was significantly higher in the ATT group than the no ATT group. Patients with ATT had significantly higher incidence of cardiac death (5.6 vs. 0%, p < 0.001) than those without ATT even if they did not meet the diagnostic criteria of familial hypercholesterolemia. A multivariate model demonstrated that ATT was independently associated with the MACE at 1-year (Hazard ratio, 2.09; 95% Confidence Interval, 1.09-4.00, p = 0.026). The presence of ATT was independently associated with 1-year recurrence of cardiovascular events in patients with CAD undergoing PCI. Assessment of ATT might be useful for risk stratification of secondary cardiovascular events.

Age- and Gender-Related Differences in Coronary Lesion Plaque Composition on Optical Coherence Tomography

BACKGROUND

The pathophysiology and chronological course of atherosclerosis seems to be different between men and women due to biological differences, and age and gender differences in plaque composition of coronary lesions remain to be elucidated.Methods and Results:A total of 860 consecutive patients with a median age of 69 years (IQR, 60-78 years) who underwent optical coherence tomography (OCT) of culprit lesions was included. The composition of culprit plaque on OCT was compared between female (n=171) and male (n=689) subjects in younger (<70 years old) and elderly (≥70 years old) patients. In elderly patients, the prevalence of thin-cap fibroatheroma (TCFA) was significantly higher in women than in men (30.6 vs. 15.2%, P<0.001). In younger patients, the prevalence of large calcification was significantly higher in women than in men (60.0 vs. 32.8%, P<0.001). The prevalence of other vulnerable plaque characteristics (i.e., macrophages, microchannels, and spotty calcification), was similar between women and men. Elderly women had a significantly higher prevalence of TCFA (OR, 2.13; 95% CI: 1.33-3.44, P=0.002) than other patients.

CONCLUSIONS

Women had a higher prevalence of TCFA and of large calcification than men in patients ≥70 and <70 years old, respectively. This may facilitate the understanding of gender differences in the pathogenesis of coronary atherosclerosis, and the tailoring of therapy and of prevention according to age and gender.

Plaque morphology assessed by optical coherence tomography in the culprit lesions of the first episode of acute myocardial infarction in patients with low low-density lipoprotein cholesterol level

BACKGROUND

There remains a residual risk for acute myocardial infarction (AMI) even with low low-density lipoprotein cholesterol (LDL-C) levels. This study aimed to characterize the culprit lesion morphology of AMI by optical coherence tomography (OCT) in patients with low LDL-C.

METHODS

Four-hundred and nine culprit lesions of 409 patients with their first presentation of AMI imaged by OCT were investigated. OCT analysis included the presence of plaque rupture and thin-capped fibroatheroma (TCFA). Fibrous cap thickness and lipid length were also measured. Intravascular ultrasound (IVUS) was performed in 368 (90.0%) patients. OCT and IVUS findings were compared between patients with LDL-C < 100 mg/dl (lower-LDL group) and those with LDL ≥ 100 mg/dl (higher-LDL group).

RESULTS

Lower-LDL group included 93 (22.7%) patients. Plaque rupture (54.8% vs. 68.7%, p = 0.018) and TCFA (39.8% vs. 54.6%, p = 0.013) were less frequently observed in lower-LDL than in higher-LDL. Fibrous cap was thicker [73 (59-109) µm vs. 63 (57-83) µm, p = 0.028] and lipid length was smaller [5.4 (2.3-9.9) mm vs. 7.1 (4.1-10.5) mm, p = 0.012] in lower-LDL than in higher-LDL. There were no significant differences in IVUS parameters including plaque burden or remodeling index between the two groups.

CONCLUSIONS

Patients with lower LDL-C showed more prevalent intact fibrous cap and less vulnerable features in the culprit lesions, which may suggest the need for exploring a specific strategy for the prevention of plaque erosion in low LDL-C subjects.