Cardiac outcomes in patients with acute coronary syndrome attributable to calcified nodule

Characteristics of calcified nodule attributable to culprit lesion in acute coronary syndrome: A systematic review and meta-analysis

The presence of calcified nodule (CN) is a significant characteristic of atherothrombosis in acute coronary syndrome (ACS). However, its characteristics continue to be understudied. This review aimed to further investigate these characteristics. This study found that CN was a distinctive feature of an atheromatous plaque, representing 6.3% of ACS. CN was more common in NSTE-ACS than in STEMI patients (9.4% vs. 6.6%). CN was also chiefly observed in the left anterior descendant artery (48%), followed by the right coronary (40.4%) and left circumflex (14.5%) arteries. Higher prevalence of hypertension (78.8%), diabetes mellitus (50.8%), multivessel disease (71.7%), and kidney disease (26.43%) were noted in CN compared to non-CN patients. CN-associated ACS also 6-fold increased the risk of target lesion revascularization compared to those without CN.

Distinct Challenges of Eruptive and Non-Eruptive Calcified Nodules in Percutaneous Coronary Intervention

PURPOSE OF REVIEW

To provide a summary of prevalence, pathogenesis, and treatment of coronary calcified nodules (CNs).

RECENT FINDINGS

CNs are most frequently detected at the sites of hinge motion of severely calcified lesions such as in the middle segment of right coronary artery and left main coronary bifurcation. On histopathology, CNs exhibit two distinctive morphologies: eruptive and non-eruptive. Eruptive CNs, which have a disrupted fibrous cap with adherent thrombi, are biologically active. Non-eruptive CNs, which have an intact fibrous cap without thrombi, are biologically inactive, representing either healed eruptive CNs or protrusion of calcium due to plaque progression. Recent studies using optical coherence tomography (OCT) have shown a difference in the mechanism of stent failure in the two subtypes, demonstrating early reappearance of eruptive CNs in the stent (at ~ 6 months) as a unique mechanism of stent failure that does not seem to be preventable by simply achieving adequate stent expansion. The cause of CN reappearance in stent is not known and could be due to acute or subacute intrusion or continued growth of the CN. Whether modification of CN is needed, the most effective calcium modification modality and effectiveness of stent implantation in eruptive CNs has not been elucidated. In this review, we discuss pathogenesis of CNs and how intravascular imaging can help diagnose and manage patients with CNs. We also discuss medical and transcatheter therapies beyond conventional stent implantation for effective treatment of eruptive CNs that warrant testing in prospective studies.

Mechanism of Stent Failure in Patients With Eruptive Calcified Nodule Treated With Rotational Atherectomy

BACKGROUND

Percutaneous coronary intervention (PCI) for lesions with eruptive calcified nodules (CNs) is associated with worse outcomes compared with that for other calcified lesions. We aimed to clarify the relationship between eruptive CNs at index PCI, optical coherence tomography (OCT) findings at the 8-month follow-up, and clinical outcomes using serial OCT.

METHODS

This retrospective observational study used data from a prospective, single-centre registry. We conducted consecutive PCI for calcified lesions requiring rotational atherectomy (RA) with OCT guidance. We categorized 51 patients (54 lesions) into those with (16 patients [16 lesions]) and without eruptive CNs (35 patients [38 lesions]).

RESULTS

Post-PCI, stent expansion was comparable between the 2 groups, and CN-like protrusion was found in 75% of lesions with eruptive CNs. Follow-up OCT at 8 months revealed in-stent CNs in 54% of treated eruptive CN lesions, whereas lesions without eruptive CNs lacked in-stent CNs. Multivariate linear regression analysis demonstrated that eruptive CN was associated with maximum neointimal tissue (NIT) thickness (regression coefficient 0.303; 95% confidence interval, 0.057-0.549; P = 0.02). Consequently, patients with eruptive CNs exhibited a higher clinically driven target lesion revascularization (TLR) rate than did those without at 1 year (31.3% vs 2.9%, P = 0.009) and 5 years (43.8% vs 11.4%, P = 0.02). TLR primarily occurred in lesions with maximum eruptive CN arc angles > 180°.

CONCLUSIONS

Following RA treatment with acceptable stent expansion, eruptive CNs before PCI correlated with greater NIT formation with in-stent CNs, resulting in a higher TLR rate, particularly in lesions with maximum eruptive CN arc angles exceeding 180°.

Coronary calcified nodules versus nonnodular coronary calcifications: a systematic review and meta-analysis

BACKGROUND

Percutaneous coronary intervention (PCI) on severely calcified coronary lesions is challenging. Coronary calcified nodule (CN) refers to an eccentric and protruding coronary calcification associated with plaque vulnerability and adverse clinical events. This study aims to conduct an extensive review of CNs, focusing on its prognostic impact in comparison with nonnodular coronary calcification (N-CN).

METHOD

A systematic literature review on PubMed, MEDLINE, and EMBASE databases was conducted for relevant articles. Observational studies or randomized controlled trials comparing CNs and N-CNs were included.

RESULTS

Five studies comparing CNs and N-CNs were pertinent for inclusion. The total number of individuals across these studies was 1456. There were no significant differences in the baseline demographic, clinical, and angiographic data between the CN and N-CN groups. Intracoronary imaging was always utilized. At follow-up, CNs were associated with significantly increased, target vessel revascularization [odds ratio (OR) 2.16; 95% confidence interval (CI): 1.39-3.36, P-value < 0.01, I2 = 0%] and stent thrombosis (OR 9.29; 95% CI: 1.67-51.79, P-value = 0.01, I2 = 0%) compared with N-CN. A trend for greater cardiac death was also assessed in the CN group (OR 1.75; 95% CI: 0.98-3.13, P-value = 0.06, I2 = 0%).

CONCLUSION

CN has a significantly negative impact on outcomes when compared with N-CN.

Calcified Nodule in Percutaneous Coronary Intervention: Therapeutic Challenges

Calcified nodules (CNs) are among the most challenging lesions to treat in contemporary percutaneous coronary intervention. CNs may be divided into 2 subtypes, eruptive and noneruptive, which have distinct histopathological and prognostic features. An eruptive CN is a biologically active lesion with a disrupted fibrous cap and possibly adherent thrombus, whereas a noneruptive CN has an intact fibrous cap and no adherent thrombus. The use of intravascular imaging may allow differentiation between the 2 subtypes, thus potentially guiding treatment strategy. Compared with noneruptive CNs, eruptive CNs are more likely to be deformable, resulting in better stent expansion, but are paradoxically associated with worse clinical outcomes, in part because of their frequent initial presentation as an acute coronary syndrome and subsequent reprotrusion of the CN into the vessel lumen through the stent struts. Pending the results of ongoing studies, a tailored therapeutic approach based on the distinct features of the different CNs may be of value.

Coronary Plaque Erosion: Epidemiology, Diagnosis, and Treatment

Plaque erosion (PE), a distinct etiology of acute coronary syndromes (ACSs), is often overshadowed by plaque ruptures (PRs). Concerning its epidemiology, PE has garnered increasing recognition, with recent studies revealing its prevalence to be approximately 40% among ACS patients, challenging earlier assumptions based on autopsy data. Notably, PE exhibits distinct epidemiological features, preferentially affecting younger demographics, particularly women, and often manifesting as a non-ST-segment elevation myocardial infarction. There are seasonal variations, with PE events being less common in winter, potentially linked to physiological changes and cholesterol solidification, while peaking in summer, warranting further investigation. Moving to molecular mechanisms, PE presents a unique profile characterized by a lesser degree of inflammation compared to PR, with endothelial shear stress emerging as a plausible molecular mechanism. Neutrophil activation, toll-like receptor-2 pathways, and hyaluronidase 2 expression are among the factors implicated in PE pathophysiology, underscoring its multifactorial nature. Advancements in intravascular imaging diagnostics, particularly optical coherence tomography and near-infrared spectroscopy coupled with intravascular ultrasound, offer unprecedented insights into plaque composition and morphology. Artificial intelligence algorithms show promise in enhancing diagnostic accuracy and streamlining image interpretation, augmenting clinician decision-making. Therapeutically, the management of PE evolves, with studies exploring less invasive approaches such as antithrombotic therapy without stenting, particularly in cases identified early through intravascular imaging. Additionally, the potential role of drug-coated balloons in reducing thrombus burden and minimizing future major adverse cardiovascular events warrants further investigation. Looking ahead, the integration of advanced imaging modalities, biomarkers, and artificial intelligence promises to revolutionize the diagnosis and treatment of coronary PE, ushering in a new era of personalized and precise cardiovascular care.

Mechanisms of Very Late Stent Thrombosis in Japanese Patients as Assessed by Optical Coherence Tomography

BACKGROUND

Although very late stent thrombosis (VLST) remains an important concern, the underlying etiology and clinical characteristics are not fully elucidated in Japanese patients who undergo intravascular imaging-guided percutaneous coronary intervention (PCI) regularly.

METHODS

We identified 50 VLST lesions (bare-metal stent [BMS] [n = 16], first-generation drug-eluting stent [DES] [n = 14] and newer-generation DES [n = 20]) in patients managed in our institutes. The underlying mechanism of VLST was assessed by optical coherence tomography (OCT), and the major etiology of each lesion was determined. The aim of this study was to explore the mechanisms of VLST of BMSs and DESs in Japanese patients.

RESULTS

The median duration since stent implantation was 10 years (range: 1-20). The most frequent etiology of VLST was neoatherosclerotic rupture (44%), followed by neointimal erosion (24%). Edge disease (10%) and evagination (10%) were similarly observed. Malapposition (8%) was deemed to be acquired late by looking at intravascular imaging from the index procedure. Uncovered struts (2%) and in-stent calcified nodule (2%) were the least frequent etiologies. Regardless of etiology, signs of neoatherosclerosis were present in most lesions (82%). Most patients received single (68%) or dual (8%) antiplatelet therapy or oral anticoagulation alone (4%), whereas a considerable proportion of patients discontinued medication (20%). Regarding the treatment strategy, drug-coated balloon was the most frequent strategy (56%), followed by implantation of newer DESs (34%).

CONCLUSIONS

Various mechanisms have been identified in Japanese patients with VLST. In these patients, biological responses seemed to be more relevant than the index procedure-related factors.

Clinical Impact of In-Stent Calcification in Coronary Arteries: Optical Coherence Tomography Study

In-stent restenosis with neoatherosclerosis has been known as the predictor of target lesion revascularization (TLR) after percutaneous coronary intervention. However, the impact of in-stent calcification (ISC) alone on clinical outcomes remains unknown since neoatherosclerosis by optical coherence tomography includes in-stent lipid and calcification. We aimed to assess the effect of ISC on clinical outcomes and clinical differences among different types of ISC. We included 126 lesions that underwent optical coherence tomography-guided percutaneous coronary intervention and divided those into the ISC group (n = 38) and the non-ISC group (n = 88) according to the presence of ISC. The cumulative incidence of clinically driven TLR (CD-TLR) was compared between the ISC and non-ISC groups. The impact of in-stent calcified nodule and nodular calcification on CD-TLR was evaluated using the Cox hazard model. The incidence of CD-TLR was significantly higher in the ISC group than in the non-ISC group (p = 0.004). In the multivariate Cox hazard model, ISC was significantly associated with CD-TLR (hazard ratio [HR] 3.58, 95% confidence interval [CI] 1.33 to 9.65, p = 0.01). In-stent calcified nodule/nodular calcification and in-stent nodular calcification alone were also the factors significantly associated with CD-TLR (HR 3.34, 95%CI 1.15 to 9.65, p = 0.03 and HR 5.21, 95%CI 1.82 to 14.91, p = 0.002, respectively). ISC without in-stent calcified nodule/nodular calcification, which was defined as in-stent smooth calcification, was not associated with CD-TLR. In conclusion, ISC was associated with a higher rate of CD-TLR. The types of calcifications that led to a high rate of CD-TLR were in-stent calcified nodule/nodular calcification and in-stent nodular calcification alone but not in-stent smooth calcification. In-stent calcified nodule and nodular calcification should be paid more attention.

Ostial right coronary artery lesion morphology and outcomes after treatment with drug-eluting stents

BACKGROUND

Outcomes after percutaneous coronary intervention (PCI) for de novo ostial right coronary artery (RCA) lesions are poor.

AIMS

We used intravascular ultrasound (IVUS) to clarify the morphological patterns of de novo ostial RCA lesions and their associated clinical outcome.

METHODS

Among 5,102 RCA IVUS studies, 170 de novo ostial RCA stenoses (within 3 mm from the aorto-ostium) were identified. These were classified as 1) isolated ostial lesions (no disease extending beyond 10 mm from the ostium and without a calcified nodule [CN]); 2) ostial CN, typically with diffuse disease (disease extending beyond 10 mm); and 3) ostial lesions with diffuse disease but without a CN. The primary outcome was target lesion failure (TLF: cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischaemia-driven target lesion revascularisation).

RESULTS

The prevalence of an isolated ostial lesion was 11.8% (n=20), 47.6% (n=81) were ostial CN, and 40.6% (n=69) were ostial lesions with diffuse disease. Compared to ostial lesions with diffuse disease, isolated lesions were more common in women (75.0% vs 42.0%; p=0.01), and CN were associated with older age (median [first, third quartile] 76 [70, 83] vs 69 [63, 81] years old; p=0.002). The Kaplan-Meier rate of TLF at 2 years was significantly higher in patients with CN (21.6%) compared to diffuse lesions (8.2%) (p=0.04), and patients with isolated lesions had no events. A multivariable Cox proportional hazard model revealed that CN were significantly associated with TLF (hazard ratio 6.63, 95% confidence interval: 1.28-34.3; p=0.02).

CONCLUSIONS

Ostial RCA lesions have specific morphologies - detectable by IVUS - that may be associated with long-term clinical outcomes.

Coronary intravascular lithotripsy in contemporary practice: challenges and opportunities in coronary intervention

Percutaneous coronary intervention (PCI) of calcified coronary arteries is associated with poor outcomes. Poorly modified calcified lesion hinders the stent delivery, disrupts drug-carrying polymer, impairs drug elution kinetics and results in under-expanded stent (UES). UES is the most common cause of acute stent thrombosis and in-stent restenosis after PCI of calcified lesions. Angiography has poor sensitivity for recognition and quantification of coronary calcium, thereby mandating the use of intravascular imaging. Intravascular imaging, like intravascular ultrasound and optical coherence tomography, has the potential to accurately identify and quantify the coronary calcium and to guide appropriate modification device before stent placement. Available options for the modification of calcified plaque include modified balloons (cutting balloon, scoring balloon and high-pressure balloon), atherectomy devices (rotational atherectomy and orbital atherectomy) and laser atherectomy. Coronary intravascular lithotripsy (IVL) is the newest addition to the tool box for calcified plaque modification. It produces the acoustic shockwaves, which interact with the coronary calcium to cause multiplanar fractures. These calcium fractures increase the vessel compliance and result in desirable minimum stent areas. Coronary IVL has established its safety and efficacy for calcified lesion in series of Disrupt CAD trials. Its advantages over atherectomy devices include ease of use on workhorse wire, ability to modify deep calcium, no debris embolization causing slow flow or no-flow and minimal thermal injury. It is showing promising results in modification of difficult calcified lesion subsets such as calcified nodule, calcified left main bifurcation lesions and chronic total occlusion. In this review, authors will summarize the mechanism of action for IVL, its role in contemporary practice, evidence available for its use, its advantages over atherectomy devices and its imaging insight in different calcified lesion scenarios.

Comparative Clinical Implications of Calcified versus Non-Calcified Tissue Protrusion After Coronary Stent Implantation

Purpose

The prognostic implications of calcified versus non-calcified tissue protrusions (TPs) following stent implantation remain undetermined. This study aimed to evaluate the differential clinical outcomes associated with calcified and non-calcified TP morphologies.

Patients and Methods

Employing intravascular ultrasound (IVUS), we identified calcified TPs as calcium fragment extrusions permeating the stent struts, while non-calcified TPs were characterized as plaque and/or thrombus extensions through the stent into the arterial lumen. The primary endpoint encompassed target lesion failure (TLF), comprising cardiac death, target vessel myocardial infarction, clinically driven target lesion revascularization (TLR), or stent thrombosis, assessed in patients with a follow-up period exceeding one year.

Results

Of 1033 patients subjected to pre- and post-intervention IVUS, 62 exhibited calcified TPs (6.0%), and 279 presented non-calcified TPs (27.0%), forming the basis of this analysis. Multivariable linear regression indicated calcified nodules as a significant predictor of calcified TP [Odds Ratio (OR) 2.47; 95% Confidence Interval (CI) 2.33 to 2.62; P <0.001], with ST-segment elevation myocardial infarction emerging as an inverse correlate [OR 0.82; 95% CI 0.73 to 0.93; P = 0.004]. Two-year data revealed a higher incidence of TLF in patients with calcified TPs versus their non-calcified counterparts (11.3% vs 2.2%, P <0.001), and a marked increase in clinically driven TLR (9.7% vs 1.4%, P <0.001). Calcified TPs were independently correlated with increased TLF risk in the adjusted model [Hazard Ratio (HR) 2.47; 95% CI 1.17 to 5.16; P = 0.027].

Conclusion

After drug-eluting stent implantation, IVUS-identified calcified TPs correlate with adverse clinical outcomes compared to non-calcified TP formations.

The microenvironment of the atheroma expresses phenotypes of plaque instability

Data from histopathology studies of human atherosclerotic tissue specimens and from vascular imaging studies support the concept that the local arterial microenvironment of a stable atheroma promotes destabilizing conditions that result in the transition to an unstable atheroma. Destabilization is characterized by several different plaque phenotypes that cause major clinical events such as acute coronary syndrome and cerebrovascular strokes. There are several rupture-associated phenotypes causing thrombotic vascular occlusion including simple fibrous cap rupture of an atheroma, fibrous cap rupture at site of previous rupture-and-repair of an atheroma, and nodular calcification with rupture. Endothelial erosion without rupture has more recently been shown to be a common phenotype to promote thrombosis as well. Microenvironment features that are linked to these phenotypes of plaque instability are neovascularization arising from the vasa vasorum network leading to necrotic core expansion, intraplaque hemorrhage, and cap rupture; activation of adventitial and perivascular adipose tissue cells leading to secretion of cytokines, growth factors, adipokines in the outer artery wall that destabilize plaque structure; and vascular smooth muscle cell phenotypic switching through transdifferentiation and stem/progenitor cell activation resulting in the promotion of inflammation, calcification, and secretion of extracellular matrix, altering fibrous cap structure, and necrotic core growth. As the technology evolves, studies using noninvasive vascular imaging will be able to investigate the transition of stable to unstable atheromas in real time. A limitation in the field, however, is that reliable and predictable experimental models of spontaneous plaque rupture and/or erosion are not currently available to study the cell and molecular mechanisms that regulate the conversion of the stable atheroma to an unstable plaque.

Diagnosis and Prognostic Value of the Underlying Cause of Acute Coronary Syndrome in Optical Coherence Tomography-Guided Emergency Percutaneous Coronary Intervention

Background The prognostic impact of optical coherence tomography-diagnosed culprit lesion morphology in acute coronary syndrome (ACS) has not been systematically examined in real-world settings. Methods and Results This investigator-initiated, prospective, multicenter, observational study was conducted at 22 Japanese hospitals to identify the prevalence of underlying ACS causes (plaque rupture [PR], plaque erosion [PE], and calcified nodules [CN]) and their impact on clinical outcomes. Patients with ACS diagnosed within 24 hours of symptom onset undergoing emergency percutaneous coronary intervention were enrolled. Optical coherence tomography-guided percutaneous coronary intervention recipients were assessed for underlying ACS causes and followed up for major adverse cardiac events (cardiovascular death, myocardial infarction, heart failure, or ischemia-driven revascularization) at 1 year. Of 1702 patients with ACS, 702 (40.7%) underwent optical coherence tomography-guided percutaneous coronary intervention for analysis. PR, PE, and CN prevalence was 59.1%, 25.6%, and 4.0%, respectively. One-year major adverse cardiac events occurred most frequently in patients with CN (32.1%), followed by PR (12.4%) and PE (6.2%) (log-rank P<0.0001), primarily driven by increased cardiovascular death (CN, 25.0%; PR, 0.7%; PE, 1.1%; log-rank P<0.0001) and heart failure trend (CN, 7.1%; PR, 6.8%; PE, 2.2%; log-rank P<0.075). On multivariate Cox regression analysis, the underlying ACS cause was associated with 1-year major adverse cardiac events (CN [hazard ratio (HR), 4.49 [95% CI, 1.35-14.89], P=0.014]; PR (HR, 2.18 [95% CI, 1.05-4.53], P=0.036]; PE as reference). Conclusions Despite being the least common, CN was a clinically significant underlying ACS cause, associated with the highest future major adverse cardiac events risk, followed by PR and PE. Future studies should evaluate the possibility of ACS underlying cause-based optical coherence tomography-guided optimization.

Feasibility of rotational atherectomy in patients with acute coronary syndrome: favorable in-hospital outcomes and clinical importance of complexed coronary atherosclerosis

The feasibility of rotational atherectomy (RA) during percutaneous coronary intervention (PCI) in patients who present with acute coronary syndrome (ACS) remains fully unsettled. We retrospectively evaluated 198 consecutive patients who underwent RA during PCI from 2009 to 2020. All patients underwent intracoronary imaging (intravascular ultrasound 96.5%, optical coherence tomography 9.1%, both 5.6%) during PCI. Patients who underwent RA during PCI were divided into two groups: ACS (n = 49; unstable angina pectoris, n = 27; non-ST-elevation myocardial infarction, n = 18, and ST-elevation myocardial infarction, n = 4) and chronic coronary syndrome (CCS) (n = 149). The RA procedural success rate was comparable between in the ACS and CCS groups (93.9 vs. 89.9%, P = 0.41). No significant differences were observed in procedural complications and in-hospital death between the groups. The incidence of major adverse cardiovascular event (MACE) after 2 years was significantly higher in ACS group compared with CCS group (38.7 vs. 17.4%, log-rank P = 0.002). Multivariable Cox regression analysis identified SYNTAX score or CABG SYNTAX score > 22 (hazard ratio (HR) 2.66, 95% confidence interval (CI) 1.40-5.06, P = 0.002) and mechanical circulatory support during the procedure (HR 2.61, 95% CI 1.21-5.59, P = 0.013) as predictors of MACE at 2 years, but not ACS on index admission (HR 1.58, 95% CI 0.84-2.99, P = 0.151). RA procedure is feasible as a bail-out strategy for ACS lesions. However, more complexed coronary atherosclerosis and mechanical circulatory support during RA procedure, but no ACS lesions were associated with worse mid-term clinical outcomes.

Clinical impact of optical coherence tomography findings after drug-coated balloon treatment for patients with acute coronary syndromes

BACKGROUND

Drug-coated balloon (DCB) became a potential treatment option for patients with acute coronary syndrome (ACS); however, factors associated with target lesion failure (TLF) remain uncertain.

METHODS

This retrospective, multicentre, observational study included consecutive ACS patients who underwent optical coherence tomography (OCT)-guided DCB treatment. Patients were divided into two groups according to the occurrence of TLF, a composite of cardiac death, target vessel-related myocardial infarction, and ischemia-driven target lesion revascularisation.

RESULTS

We enrolled 127 patients in this study. During the median follow-up period of 562 (IQR: 342-1164) days, 24 patients (18.9%) experienced TLF, and 103 patients (81.1%) did not. The cumulative 3-year incidence of TLF was 22.0%. The cumulative 3-year incidence of TLF was the lowest in patients with plaque erosion (PE) (7.5%), followed by those with rupture (PR) (26.1%) and calcified nodule (CN) (43.5%). Multivariable Cox regression analysis revealed that plaque morphology was independently associated with TLF on pre-PCI (percutaneous coronary intervention) OCT, and residual thrombus burden (TB) was positively associated with TLF on post-PCI OCT. Further stratification by post-PCI TB revealed a comparable incidence of TLF in patients with PR (4.2%) to that of PE if the culprit lesion had a smaller post-PCI TB than the cut-off value (8.4%). TLF incidence was high in patients with CN, regardless of TB size on post-PCI OCT.

CONCLUSIONS

Plaque morphology was strongly associated with TLF for ACS patients after DCB treatment. Residual TB post-PCI might be a key determinant for TLF, especially in patients with PR.

Mechanisms and treatment outcomes of ostial right coronary artery in-stent restenosis

BACKGROUND

Despite a high rate of in-stent restenosis (ISR) after stenting the right coronary artery (RCA) ostium, the mechanism of ostial RCA ISR is not well understood.

AIMS

We aimed to clarify the cause of ostial RCA ISR using intravascular ultrasound (IVUS).

METHODS

Overall, 139 ostial RCA ISR lesions were identified with IVUS, pre-revascularisation. Primary ISR mechanisms were classified as follows: 1) neointimal hyperplasia (NIH); 2) neoatherosclerosis; 3) ostium not covered by the stent; 4) stent fracture or deformation; 5) stent underexpansion (old minimum stent area <4.0 mm2 or stent expansion <50%); or 6) a protruding calcified nodule.

RESULTS

The median duration from prior stenting was 1.2 (first quartile 0.6, third quartile 3.1) years. The primary mechanisms of ISR were NIH in 25% (n=35) of lesions, neoatherosclerosis in 22% (n=30), uncovered ostium in 6% (n=9) (biological cause 53%, n=74), stent fracture or deformation in 25% (n=35), underexpansion in 11% (n=15), and protruding calcified nodules in 11% (n=15) (mechanical cause 47%, n=65). Including secondary mechanisms, 51% (n=71) of ostial RCA ISRs had stent fractures that were associated with greater hinge motion of the ostial-aorta angle during the cardiac cycle. The Kaplan-Meier rate of target lesion failure at 1 year was 11.5%. When the mechanically caused ISRs were treated without new stents, they suffered a higher subsequent event rate (41.4%) compared with non-mechanical causes or mechanical causes treated without restenting (7.8%, unadjusted hazard ratio 6.44, 95% confidence interval: 2.33-17.78; p<0.0001).

CONCLUSIONS

Half of the ostial RCA ISRs were due to mechanical causes. Subsequent event rates were high, especially in mechanically caused ISRs treated without the implantation of a new stent.

Angiographic Coronary Calcification: A Simple Predictor of Long-Term Clinical Outcomes in Patients with Acute Myocardial Infarction

AIMS

Coronary calcification detected by coronary angiography is a simple risk marker for long-term clinical outcomes in stable coronary artery disease. However, the significance of angiographic coronary calcification in the culprit lesion of acute myocardial infarction (AMI) has not been fully discussed. The purpose of this retrospective study was to assess the usefulness of angiographic coronary calcification as a risk marker for long-term clinical outcomes following percutaneous coronary intervention to the culprit lesions of AMI.

METHODS

We included 1209 patients with AMI and divided them into the none-mild calcification group (n=923) and the moderate-severe calcification group (n=286) according to angiographic coronary calcification in the culprit lesion of AMI. The primary endpoint was the occurrence of major adverse cardiac events (MACE), which was defined as a composite of all-cause death, nonfatal MI, readmission for heart failure, and ischemia-driven target vessel revascularization.

RESULTS

The median follow-up duration was 542 (Q1: 182, Q3: 990) days. A total of 345 MACE were observed during the study period. The occurrence of MACE was significantly greater in the moderate-severe calcification group than in the none-mild calcification group (43.4% vs. 23.9%, p＜0.001). In the multivariate Cox hazard model, moderate-severe calcification was significantly associated with MACE (hazard ratio 1.302, 95% confidence interval 1.011-1.677, p=0.041) after controlling multiple confounding factors.

CONCLUSIONS

Angiographically moderate to severe calcification in AMI culprit lesion was associated with long-term worse clinical outcomes. Angiographic coronary calcification can be a simple risk marker in patients after AMI.

Pathophysiology of Acute Coronary Syndromes-Diagnostic and Treatment Considerations

Coronary artery disease and acute coronary syndromes are accountable for significant morbidity and mortality, despite the preventive measures and technological advancements in their management. Thus, it is mandatory to further explore the pathophysiology in order to provide tailored and more effective therapies, since acute coronary syndrome pathogenesis is more varied than previously assumed. It consists of plaque rupture, plaque erosion, and calcified nodules. The advancement of vascular imaging tools has been critical in this regard, redefining the epidemiology of each mechanism. When it comes to acute coronary syndrome management, the presence of ruptured plaques almost always necessitates emergent reperfusion, whereas the presence of plaque erosions may indicate the possibility of conservative management with potent antiplatelet and anti-atherosclerotic medications. Calcified nodules, on the other hand, are an uncommon phenomenon that has largely gone unexplored in terms of the best management plan. Future studies should further establish the importance of detecting the underlying mechanism and the role of various treatment plans in each of these distinct entities.

Predictors of target lesion revascularisation after drug-eluting stent implantation for calcified nodules: an optical coherence tomography study

BACKGROUND

Evidence of prognostic factors for stent failure after drug-eluting stent implantation for calcified nodules (CNs) is limited.

AIMS

We aimed to clarify the prognostic risk factors associated with stent failure among patients who underwent drug-eluting stent implantation for CN lesions using optical coherence tomography (OCT).

METHODS

This retrospective, multicentre, observational study included 108 consecutive patients with CNs who underwent OCT-guided percutaneous coronary intervention (PCI). To evaluate the quality of CNs, we measured their signal intensity and analysed the degree of signal attenuation. All CN lesions were divided into dark or bright CNs according to the half width of signal attenuation, greater or lower than 332, respectively.

RESULTS

During the median follow-up period of 523 days, 25 patients (23.1%) experienced target lesion revascularisation (TLR). The 5-year cumulative incidence of TLR was 32.6%. Multivariable Cox regression analysis revealed that younger age, haemodialysis, eruptive CNs, dark CNs assessed by pre-PCI OCT, disrupted fibrous tissue protrusions, and irregular protrusions assessed by post-PCI OCT were independently associated with TLR. The prevalence of in-stent CNs (IS-CNs) observed at follow-up OCT was significantly higher in the TLR group than in the non-TLR group.

CONCLUSIONS

Factors such as younger age, haemodialysis, eruptive CNs, dark CNs, disrupted fibrous tissue, or irregular protrusions were independently related to TLR in patients with CNs. The high prevalence of IS-CNs might indicate that the main cause of stent failure implanted in CN lesions could be the recurrence of CN progression in the stented segment.

Impact of Eruptive vs Noneruptive Calcified Nodule Morphology on Acute and Long-Term Outcomes After Stenting

BACKGROUND

Whether an eruptive or noneruptive target lesion calcified nodule (CN) portends worse acute and long-term clinical outcomes after stenting has not been established.

OBJECTIVES

The authors sought to compare acute and long-term clinical outcomes in eruptive CN vs noneruptive CN morphology.

METHODS

Using optical coherence tomography, an eruptive CN was defined as an accumulation of small calcium fragments protruding and disrupting the overlying fibrous cap, typically with small amount of thrombus. A noneruptive CN was defined as an accumulation of small calcium fragments with a smooth intact fibrous cap without an overlying thrombus. The primary endpoint was target lesion failure (TLF) including cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization in patients with ≥6-month follow-up.

RESULTS

Among 3,231 patients with evaluable pre- and postintervention OCT, 236 patients had lesions with CNs (7.3%). After eliminating 4 secondary lesions and 6 patients without ≥6-month follow-up, 126 (54.8%) lesions with eruptive CNs and 104 (45.2%) lesions with noneruptive CNs formed the current report. Compared with noneruptive CNs, eruptive CNs were independently associated with greater stent expansion (89.2% ± 18.7% vs. 81.5% ± 18.9%; P = 0.003) after adjusting for morphologic and procedural factors. At 2 years, eruptive CNs trended toward more TLF compared with noneruptive CNs (Kaplan-Meier estimates, 19.8% vs 12.5%; P = 0.11) and significantly more target lesion revascularization (18.3% vs 9.6%; P = 0.04). In the adjusted model, eruptive CNs were independently associated with 2-year TLF (HR: 2.07; 95% CI: 1.01-4.50; P = 0.048).

CONCLUSIONS

Compared with noneruptive CN morphology, lesions with an eruptive CN appearance on optical coherence tomography had a worse poststent long-term clinical outcome despite better acute stent expansion.

Roles of Vascular Smooth Muscle Cells in Atherosclerotic Calcification

The accumulation of calcium in atherosclerotic plaques is a prominent feature of advanced atherosclerosis, and it has a strong positive correlation with the total burden of atherosclerosis. Atherosclerotic calcification usually appears first at the necrotic core, indicating that cell death and inflammatory processes are involved in calcification. During atherosclerotic inflammation, various cell types, such as vascular smooth muscle cells, nascent resident pericytes, circulating stem cells, or adventitial cells, have been assumed to differentiate into osteoblastic cells, which lead to vascular calcification. Among these cell types, vascular smooth muscle cells are considered a major contributor to osteochondrogenic cells in the atherosclerotic milieu. In this review, we summarize the molecular mechanisms underlying the osteochondrogenic switch of vascular smooth muscle cells in atherosclerotic plaques.

Contemporary percutaneous management of coronary calcification: current status and future directions

Severe coronary artery calcification is one of the greatest challenges in attaining success in percutaneous coronary intervention, limiting acute and long-term results. In many cases, plaque preparation is a critical prerequisite for delivery of devices across calcific stenoses and also to achieve adequate luminal dimensions. Recent advances in intracoronary imaging and adjunctive technologies now allow the operator to select the most appropriate strategy in each individual case. In this review, we will revisit the distinct advantages of a complete assessment of coronary artery calcification with imaging and application of appropriate and contemporary plaque modification technologies in achieving durable results in this complex lesion subset.

Characteristics and Pattern of Calcified Nodule and/or Nodular Calcification Detected by Intravascular Ultrasound on the Device-Oriented Composite Endpoint (DoCE) in Patients with Heavily Calcified Lesions Who Underwent Rotational Atherectomy-Assisted Percutaneous Coronary Intervention

Objectives

This study aimed to determine characteristics and pattern of a calcified nodule (CN) and/or nodular calcification (NC) detected by intravascular ultrasound (IVUS) on the device-oriented composite endpoint (DoCE) in patients with calcified lesions who underwent rotational atherectomy (RA)-assisted percutaneous coronary intervention (PCI).

Background

The characteristics and pattern of a CN and/or NC on clinical outcome remain unknown.

Methods

We retrospectively enrolled patients who underwent RA-assisted PCI at Siriraj Hospital during August 2016 to April 2020. Preprocedural IVUS imaging was mandatory. CN/NC was defined as convex shape of luminal surface and luminal side of calcium with protrusion into the coronary artery lumen as assessed by IVUS. The primary outcome was cumulative of DoCE, defined as the composite of cardiovascular death, myocardial infarction, and clinically-driven target lesion revascularization.

Results

Two hundred patients were included. Primary outcome occurred in 14%. The cumulative DoCE was significantly higher in the CN/NC group than that in the non-CN/NC group (20.7% vs. 8.8%, p = 0.022). CN/NC (p = 0.023) and MSA ≤ 5.5 mm² (p = 0.047) were correlated with a significantly higher cumulative DoCE. CN/NC was the independent predictor for the cumulative DoCE (HR = 2.96, 95% CI 1.08-8.11, p = 0.035). Pattern and characteristic of CN/NC have a prognostic value. Patients with an eccentric CN/NC had a significantly higher cumulative DoCE compared to those CN/NC with concentric calcification (p = 0.014).

Conclusion

The presence of a CN/NC in patients with heavily calcified lesions who underwent RA-assisted PCI was found to be associated with increased cumulative 5 year DoCE, especially in patients with an eccentric CN/NC. The clinical trial is registered with TCTR20210616001.

TXNIP Suppresses the Osteochondrogenic Switch of Vascular Smooth Muscle Cells in Atherosclerosis

BACKGROUND

The osteochondrogenic switch of vascular smooth muscle cells (VSMCs) is a pivotal cellular process in atherosclerotic calcification. However, the exact molecular mechanism of the osteochondrogenic transition of VSMCs remains to be elucidated. Here, we explore the regulatory role of TXNIP (thioredoxin-interacting protein) in the phenotypical transitioning of VSMCs toward osteochondrogenic cells responsible for atherosclerotic calcification.

METHODS

The atherosclerotic phenotypes of Txnip^-/- mice were analyzed in combination with single-cell RNA-sequencing. The atherosclerotic phenotypes of Tagln-Cre; Txnip^flox/flox mice (smooth muscle cell-specific Txnip ablation model), and the mice transplanted with the bone marrow of Txnip^-/- mice were analyzed. Public single-cell RNA-sequencing dataset (GSE159677) was reanalyzed to define the gene expression of TXNIP in human calcified atherosclerotic plaques. The effect of TXNIP suppression on the osteochondrogenic phenotypic changes in primary aortic VSMCs was analyzed.

RESULTS

Atherosclerotic lesions of Txnip^-/- mice presented significantly increased calcification and deposition of collagen content. Subsequent single-cell RNA-sequencing analysis identified the modulated VSMC and osteochondrogenic clusters, which were VSMC-derived populations. The osteochondrogenic cluster was markedly expanded in Txnip^-/- mice. The pathway analysis of the VSMC-derived cells revealed enrichment of bone- and cartilage-formation-related pathways and bone morphogenetic protein signaling in Txnip^-/- mice. Reanalyzing public single-cell RNA-sequencing dataset revealed that TXNIP was downregulated in the modulated VSMC and osteochondrogenic clusters of human calcified atherosclerotic lesions. Tagln-Cre; Txnip^flox/flox mice recapitulated the calcification and collagen-rich atherosclerotic phenotypes of Txnip^-/- mice, whereas the hematopoietic deficiency of TXNIP did not affect the lesion phenotype. Suppression of TXNIP in cultured VSMCs accelerates osteodifferentiation and upregulates bone morphogenetic protein signaling. Treatment with the bone morphogenetic protein signaling inhibitor K02288 abrogated the effect of TXNIP suppression on osteodifferentiation.

CONCLUSIONS

Our results suggest that TXNIP is a novel regulator of atherosclerotic calcification by suppressing bone morphogenetic protein signaling to inhibit the transition of VSMCs toward an osteochondrogenic phenotype.

Serum marker and CT characteristics of coronary calcified nodule assessed by intravascular ultrasound

Background

Calcified nodule (CN) is a type of potentially vulnerable plaque. Its formation mechanism remains unknown. This study was to assess serum marker and computed tomography angiography (CTA) characteristics of CN validated by intravascular ultrasound (IVUS).

Methods

Patients who underwent coronary CTA followed by invasive coronary angiography and IVUS were retrospectively analyzed. Serum levels of alkaline phosphatase (ALP), gamma-glutamyltransferase, and calcium were collected.

Results

IVUS detected 128 de novo calcified lesions in 79 patients with coronary artery disease (CAD). CNs were identified in 11.4% (9/79) of patients and 9.4% (12/128) of lesions. Compared with patients with non-nodular calcified plaques, CN patients had higher serum level of ALP (82.00 vs 65.00 U/L, P = 0.022) and total plaque volume (673.00 vs 467.50 mm3, P = 0.021). Multivariable analyses revealed that serum ALP level and total plaque volume were independently associated with the prevalence of CN in CAD patients with calcified plaques. At lesion level, the CN group had a higher frequency of moderate to heavy calcification on angiography (75.00% vs 40.52%, P = 0.017). In terms of CTA characteristics, plaques with CN had a more severe diameter stenosis (79.00% vs 63.00%, P = 0.007), higher plaque burden (85.40% vs 77.05%, P = 0.005), total plaque density (398.00 vs 283.50 HU, P = 0.008), but lower lipid percentage (14.65% vs 19.75%, P = 0.010) and fiber percentage (17.90% vs 25.65%, P = 0.011). Mean plaque burden is an independent predictor of the prevalence of CN in calcified plaques (odds ratio = 1.102, 95% confidence interval: 1.025–1.185, P = 0.009). The AUC is 0.753 (95% confidence interval: 0.615–0.890, P = 0.004). When using 84.85% as the best cutoff value, the diagnostic sensitivity and specificity of mean plaque burden for predicting the presence of CN within calcified plaques were 66.7% and 80.2%, respectively.

Conclusions

CN had different CTA imaging features from non-nodular coronary calcification. The presence of a CN was associated with a higher serum ALP level and plaque burden.

Prevalence and outcomes of stent thrombosis with in-stent calcified nodules: substudy from the REAL-ST registry

BACKGROUND

The relationship between in-stent calcified nodules (IS-CN) and second-generation drug-eluting stent (G2-DES) stent thrombosis (ST) remains uncertain.

AIMS

We aimed to evaluate the prevalence, clinical demographic and long-term clinical outcomes after G2-DES ST with IS-CN.

METHODS

The prespecified substudy of the REAL-ST registry (a retrospective, multicentre registry of patients with definite ST after first- and G2-DES implantation) enrolled patients who experienced definite G2-DES ST and who underwent pre-intervention intravascular ultrasound imaging at index ST events.

RESULTS

IS-CN was observed in 15 out of 118 (13%) definite G2-DES ST cases. The multiple logistic regression model demonstrated that haemodialysis (odds ratio [OR] 12.27, 95% confidence interval [CI]: 1.56-94.54; p=0.02), proximal or mid-right coronary artery lesions (OR 12.79, 95% CI: 1.78-92.13; p=0.01) and severe calcification (OR 13.01, 95% CI: 1.18-142.94; p=0.04) were independently associated with ST with IS-CN. The cumulative 5-year incidence of target lesion revascularisation (TLR) after ST was significantly higher in the IS-CN group than in the non-IS-CN group (p=0.02). Independent predictors of TLR after the index ST events were female sex (hazard ratio [HR] 3.05, 95% CI: 1.20-7.74; p=0.02), diabetes mellitus (HR 3.26, 95% CI: 1.26-8.41; p=0.01) and IS-CN (HR 3.07, 95% CI: 1.16-8.14; p=0.02).

CONCLUSIONS

IS-CN may be one of the underlying mechanisms of G2-DES ST. Notably, IS-CN was associated with a higher TLR rate after the index ST events, suggesting the need for careful clinical follow-up of ST patients with IS-CN.

Outcomes of paclitaxel-coated balloon angioplasty for in-stent calcified nodule: An optical coherence tomography study

BACKGROUND

Paclitaxel-coated balloon (PCB) angioplasty emerges as an effective therapeutic option for in-stent restenosis (ISR). However, whether PCB angioplasty would be effective for in-stent calcified nodule (ISCN) lesions remain fully understood. This study aimed to evaluate the frequency and outcomes of ISCN in patients undergoing PCB angioplasty for ISR after second-generation drug-eluting stents (G2-DES) implantation.

METHODS

This study enrolled 179 lesions (160 patients) undergoing PCB angioplasty for G2-DES restenosis with optical coherence tomography guidance. According to the presence of ISCN at the minimum lumen area, the lesions were divided into two groups: the ISCN (n = 16) and the non-ISCN groups (n = 163). The primary study endpoint was the cumulative 3-year incidence of target lesion failure (TLF; a composite of cardiac death, clinically driven target vessel revascularization, and definite stent thrombosis) on a lesion basis.

RESULTS

ISCN was observed in 16 of 179 lesions (8.9%). Cumulative 3-year incidence of TLF was significantly higher in the ISCN group than in the non-CN group (85.3% vs. 16.9%, inverse probability weighted hazard ratio [HR] 4.46, 95% confidence intervals [CIs]: 2.42-8.22, p < 0.001). Risk factors associated with TLF were ISCN (HR 4.55, 95% CI: 1.56-13.3, p = 0.005), recurrent ISR (HR 2.82, 95% CI: 1.50-3.30, p = 0.001), and early ISR (HR 2.18, 95% CI: 1.21-3.92, p = 0.009).

CONCLUSION

ISCN was observed in 8.3% of G2-DES restenosis. PCB angioplasty had little effect on ISCN lesions compared with non-ISCN lesions, suggesting the need for careful clinical follow-up of patients with ISCN lesions after PCB angioplasty.

Very Early Progression of an In-Stent Calcified Nodule 2 Weeks After Drug-Eluting Stent Implantation in the Calcified Lesion

In-stent calcified nodules (CNs) are one of the mechanisms of in-stent restenosis, but their underlying cause has not been elucidated. We report a case of a patient with early stent thrombosis due to an in-stent CN only 2 weeks after drug-eluting stent implantation. The fact that the in-stent CN was detected only 2 weeks after the initial percutaneous coronary intervention means that the underlying mechanism was the progression of the CN, indicating that in-stent CNs can occur even in the subacute phase. After percutaneous coronary intervention for a severe calcified lesion, very early progression of CNs can occur, and they require close follow-up and intensive antiplatelet therapy.

Coronary functional assessment in non-obstructive coronary artery disease: Present situation and future direction

Non-obstructive coronary artery disease (CAD), which is defined as coronary stenosis <50%, has been increasingly recognized as an emerging entity in clinical practice. Vasomotion abnormality and coronary microvascular dysfunction are two major mechanisms contributing to the occur of angina with non-obstructive CAD. Although routine coronary functional assessment is limited due to several disadvantages, functional evaluation can help to understand the pathophysiological mechanism and/or to exclude specific etiologies. In this review, we summarized the potential mechanisms involved in ischemia with non-obstructive coronary arteries (INOCA) and myocardial infarction with non-obstructive coronary arteries (MINOCA), the two major form of non-obstructive CAD. Additionally, we reviewed currently available functional assessment indices and their use in non-obstructive CAD. Furthermore, we speculated that novel technique combined anatomic and physiologic parameters might provide more individualized therapeutic choice for patients with non-obstructive CAD.

Heart Team Intervention for Calcified Left Main Coronary Disease and Jeopardized Left Internal Mammary Artery Graft

It is sometimes difficult to identify the culprit lesion and treatment strategy in patients with acute coronary syndrome who have complex coronary lesions and jeopardized left internal mammary artery graft. This report describes a heart team approach for a non-ST-segment elevation myocardial infarction case with complex coronary vasculature. A 73-year-old man presented to the emergency department with crescendo angina. He had a history of total aortic arch replacement with concomitant coronary artery bypass graft using left internal mammary artery. Emergent coronary angiography demonstrated severe stenosis at left main trunk bifurcation caused by calcified nodule. While the bypass graft to left anterior descending coronary artery was patent, the proximal segment of left subclavian artery was occluded. Following the prompt discussion with our heart team, we performed percutaneous coronary intervention in the first step for treating the left main stenosis using rotational atherectomy into the unprotected left circumflex artery. After clinical recovery, stress myocardial scintigraphy identified the presence of anteroseptal ischemia, which indicated coronary subclavian steal syndrome due to left subclavian artery occlusion. Contrast-enhanced CT visualized that the occlusion originated from the anastomosis, suggesting the potential procedural risk of endovascular treatment by dilatation. Our heart team discussed again and decided to undergo axillo-axillary artery bypass surgery. He was discharged 8 days after the surgery without any sequelae. This is the rare case report of non-ST-segment elevation myocardial infarction who had similar condition to coronary subclavian steal syndrome after total aortic arch replacement. This case highlights the importance of a collaborative approach of the heart team to identify the best therapeutic strategy in a patient with complex coronary vasculature.

Vascular Response After Everolimus-Eluting Stent in Acute Myocardial Infarction Caused by Calcified Nodule

BACKGROUND

Patients with acute myocardial infarction (AMI) caused by calcified nodules (CN) have worse clinical outcomes following primary percutaneous coronary intervention (PCI). This study investigated the late vascular response after everolimus-eluting stent (EES) implantation assessed by optical coherence tomography (OCT) in patients with AMI caused by CN, by comparing with plaque rupture (PR) and plaque erosion (PE).Methods and Results: Based on the OCT findings in AMI culprit lesions before PCI, a total of 141 patients were categorized into 3 groups (PR, PE, or CN), and the OCT findings immediately and 10 months after PCI were compared. The frequency of PR, PE, and CN was 85 (60%), 45 (32%), and 11 patients (8%), respectively. In the 10-month follow-up OCT, the frequency of lesions with uncovered struts and lesions with malapposed struts were highest in the CN group, followed by the PR and PE groups (82% vs. 52% vs. 40%, P=0.042 and 73% vs. 26% vs. 16%, P<0.001, respectively). The incidence of intra-stent thrombus, re-appearance of CN within the stent, and target lesion revascularization were higher in the CN group compared with the PR and PE groups (36% vs. 9% vs. 7%, P=0.028; 27% vs. 0% vs. 0%, P<0.001; and 18% vs. 2% vs. 2%, P=0.024, respectively).

CONCLUSIONS

Late arterial healing response at 10 months after EES implantation in the CN was worse compared with PR and PE in patients with AMI.

Impact of Hemodialysis Duration on Coronary Artery Calcification Among Hemodialysis Patients Who Underwent Percutaneous Coronary Intervention

Our study aimed to evaluate the prevalence and impact of coronary artery calcification (CAC) on hemodialysis (HD) patients with coronary artery disease (CAD) who underwent percutaneous coronary intervention (PCI). We enrolled 211 HD patients who underwent PCI (men: n = 155, age: 71 ± 1 0 years). Severe CAC was defined as calcification with an arc of 360° on intravascular ultrasound. Multivariate analysis was performed to determine the predictors of severe CAC. The impact of severe CAC on target lesion revascularization (TLR) was evaluated. Patients with severe CAC (46%) had a higher incidence of diabetes mellitus (DM) (79 vs 59%, P = .003) and longer HD duration (7.7 vs 3.4 years, P < .001) than those with non-severe CAC. Multivariate analysis demonstrated that DM, HD duration, and angiographic calcification were significant predictors for severe CAC (odds ratio 4.42, 1.13, and 6.62; P < .001, P < .001, and P < .001, respectively). After the median follow-up period of 580 days (interquartile range, 302-730 days), Kaplan-Meier curve analysis revealed that severe CAC was associated with an increased risk for TLR (χ² 12.7; P = .002). In HD patients with CAD after PCI, DM and HD duration were significant predictors for severe CAC. Furthermore, severe CAC was associated with an increased risk for TLR.

Diagnosis and Treatment of Acute Coronary Syndromes: A Review

IMPORTANCE

Acute coronary syndromes (ACS) are characterized by a sudden reduction in blood supply to the heart and include ST-segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), and unstable angina. Each year, an estimated more than 7 million people in the world are diagnosed with ACS, including more than 1 million patients hospitalized in the US.

OBSERVATIONS

Chest discomfort at rest is the most common presenting symptom of ACS and affects approximately 79% of men and 74% of women presenting with ACS, although approximately 40% of men and 48% of women present with nonspecific symptoms, such as dyspnea, either in isolation or, more commonly, in combination with chest pain. For patients presenting with possible ACS, electrocardiography should be performed immediately (within 10 minutes of presentation) and can distinguish between STEMI and non-ST-segment elevation ACS (NSTE-ACS). STEMI is caused by complete coronary artery occlusion and accounts for approximately 30% of ACS. ACS without significant ST-segment elevation on electrocardiography, termed NSTE-ACS, account for approximately 70% of ACS, are caused by partial or intermittent occlusion of the artery and are associated with ST-segment depressions (approximately 31%), T-wave inversions (approximately 12%), ST-segment depressions combined with T-wave inversions (16%), or neither (approximately 41%). When electrocardiography suggests STEMI, rapid reperfusion with primary percutaneous coronary intervention (PCI) within 120 minutes reduces mortality from 9% to 7%. If PCI within 120 minutes is not possible, fibrinolytic therapy with alteplase, reteplase, or tenecteplase at full dose should be administered for patients younger than 75 years without contraindications and at half dose for patients 75 years or older (or streptokinase at full dose if cost is a consideration), followed by transfer to a facility with the goal of PCI within the next 24 hours. High-sensitivity troponin measurements are the preferred test to evaluate for NSTEMI. In high-risk patients with NSTE-ACS and no contraindications, prompt invasive coronary angiography and percutaneous or surgical revascularization within 24 to 48 hours are associated with a reduction in death from 6.5% to 4.9%.

CONCLUSIONS AND RELEVANCE

Each year, an estimated more than 7 million people are diagnosed with ACS worldwide. For patients with STEMI, coronary catheterization and PCI within 2 hours of presentation reduces mortality, with fibrinolytic therapy reserved for patients without access to immediate PCI. For high-risk patients with NSTE-ACS without contraindications, prompt invasive coronary angiography followed by percutaneous or surgical revascularization is associated with lower rates of death.

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.

Increased Vulnerability and Distinct Layered Phenotype at Culprit and Nonculprit Lesions in STEMI Versus NSTEMI

OBJECTIVES

This study aimed to investigate the pancoronary plaque vulnerability (including culprit and nonculprit lesions) and layered phenotype in patients with ST-segment elevation myocardial infarction (STEMI) vs non-STEMI (NSTEMI).

BACKGROUND

Pancoronary vulnerability should account for distinct clinical manifestations of acute myocardial infarction (AMI). Layered plaque is indicative of previous coronary destabilization and thrombosis.

METHODS

A total of 464 patients with AMI who underwent 3-vessel optical coherence tomography imaging were consecutively studied and divided into a STEMI group (318 patients; 318 culprit and 1,187 nonculprit plaques) and a NSTEMI group (146 patients; 146 culprit and 560 nonculprit plaques). Patients were followed up for a median period of 2 years.

RESULTS

Compared with NSTEMI, culprit lesions in STEMI had more plaque rupture, thrombus, thin-cap fibroatheroma (TCFA), calcification, macrophage accumulation, and microvessels. The prevalence of plaque rupture (8.2% vs 4.8%; P = 0.018), microvessels (57.5% vs 45.2%; P < 0.001), and calcification (40.7% vs 30.2%; P = 0.003) at nonculprit lesions was higher in STEMI than NSTEMI. The layer area and thickness at the culprit and nonculprit lesions were significantly larger in STEMI than in NSTEMI. Multivariate analyses showed that culprit layer area (odds ratio: 1.443; 95% CI: 1.138-1.830; P = 0.002) was predictive of STEMI (vs NSTEMI), in addition to culprit TCFA, culprit thrombus, and non-left circumflex artery location of the culprit lesion. Although the type of AMI was not related to clinical outcomes, high-sensitivity C-reactive protein, culprit calcified nodule, and nonculprit TCFA predicted the 2-year major adverse cardiovascular events in patients with AMI.

CONCLUSIONS

Patients with STEMI had increased plaque vulnerability (ie, more plaque rupture and microvessels) and distinct layered phenotype at the culprit and nonculprit lesions compared with NSTEMI patients. Culprit lesion features of large layer area, TCFA, thrombus, and non-left circumflex artery location predicted the clinical presentation of STEMI.