Seung Yul Lee

The impact of obesity on subclinical coronary atherosclerosis according to the risk of cardiovascular disease

To evaluate whether the association of obesity with coronary atherosclerosis depends on the risk of cardiovascular disease (CVD).

Characteristics of Earlier Versus Delayed Presentation of Very Late Drug‐Eluting Stent Thrombosis: An Optical Coherence Tomographic Study

Background The pathophysiology underlying very late drug‐eluting stent (DES) thrombosis is not sufficiently understood. Using optical coherence tomography, we investigated characteristics of very late stent thrombosis (VLST) according to different onset times. Methods and Results A total of 98 patients from 10 South Korean hospitals who underwent optical coherence tomography for evaluation of very late DES thrombosis were retrospectively included in analyses. VLST occurred at a median of 55.1 months after DES implantation. All patients were divided into 2 equal groups of earlier versus delayed presentation of VLST, according to median onset time. In total, 27 patients were treated with next‐generation DES and 71 with first‐generation DES. Based on optical coherence tomography findings at thrombotic sites, main VLST mechanisms were as follows, in descending order: neoatherosclerosis (34.7%), stent malapposition (33.7%), and uncovered struts without stent malapposition or evagination (24.5%). Compared with patients with earlier VLST, patients with delayed VLST had lower frequency of uncovered struts without stent malapposition or evagination (34.7% versus 14.3%, respectively; P=0.019). Conversely, the frequency of neoatherosclerosis was higher in patients with delayed versus earlier VLST (44.9% versus 24.5%, respectively; P=0.034). The frequency of stent malapposition was not different between patients with earlier and delayed VLST (34.7% versus 32.7%, respectively; P=0.831). The frequency of stent malapposition, evagination, and uncovered struts was still half of delayed VLST. Conclusions The pathological mechanisms of very late DES thrombosis changed over time. Delayed neointimal healing remained a substantial substrate for VLST, even long after DES implantation.

Association between Duration of Dual Antiplatelet Therapy and Angiographic Multivessel Disease on Outcomes in Patients Treated with Newer-Generation Drug-Eluting Stents

Background—There is general agreement that the optimal duration of dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents should be individualized. We hypothesized that the extent of coronary artery disease may affect the clinical outcomes of DAPT. Methods and Results—We pooled patient-level data from 5 large, randomized trials comparing short-term DAPT with prolonged therapy. From the data, we identified 5476 patients who received newer-generation drug-eluting stents. Net adverse clinical event (NACE) was defined as a composite of all-cause mortality, myocardial infarction, stroke, or major bleeding. At 1 year, NACE had occurred in 171 patients (3.1%). Independent predictors of NACE were older age (>65 years), sex, presence of diabetes mellitus, left ventricular dysfunction (ejection fraction <40%), and angiographic multivessel disease. Multivessel disease and DAPT duration were significantly associated with NACE (P for interaction=0.002); the association was driven by the greater occurrence of myocardial infarction in patients with multivessel disease. In patients with multivessel disease, 6-month DAPT (versus 12-month DAPT) was associated with a higher incidence of myocardial infarction (adjusted hazard ratio=2.748; 95% confidence interval=1.375–5.491; P=0.004), compared with patients with single-vessel disease (P for interaction=0.001). Conclusions—In patients treated with newer-generation drug-eluting stents, a significant interaction between DAPT strategy and multivessel disease was found regarding the occurrence of NACE at 1 year. Among adverse events, myocardial infarction was more frequent in 6-month DAPT than in 12-month DAPT in patients with multivessel disease.

The Effect of Sex and Anthropometry on Clinical Outcomes in Patients Undergoing Percutaneous Coronary Intervention for Complex Coronary Lesions

Purpose To evaluate the effects of sex and anthropometry on clinical outcomes in patients who underwent percutaneous coronary intervention (PCI). Materials and Methods From three randomized trials (REal Safety and Efficacy of 3-month dual antiplatelet Therapy following Endeavor zotarolimus-eluting stent implantation, Impact of intraVascular UltraSound guidance on outcomes of Xience Prime stents in Long lesions, Chronic Total Occlusion InterVention with drUg-eluting Stents), we compared 333 pairs of men and women matched by propensity scores, all of whom underwent intravascular ultrasound (IVUS)-guided PCI for complex lesions. Results For 12 months, the incidence of adverse cardiac events, defined as the composite of cardiac death, target lesion–related myocardial infarction, and target lesion revascularization, was not different between women and men (2.4% vs. 2.4%, p=0.939). Using multivariable Coxs regression analysis, post-intervention minimum lumen area [MLA; hazard ratio (HR)=0.620, 95% confidence interval (CI)=0.423–0.909, p=0.014] by IVUS was a predictor of adverse cardiac events. Height on anthropometry and lesions with chronic total occlusion were significantly related to post-intervention MLA. However, female sex was not independently associated with post-intervention MLA. In an age and sex-adjusted model, patients in the low tertile of height exhibited a greater risk for adverse cardiac events than those in the high tertile of height (HR=6.391, 95% CI=1.160–35.206, p=0.033). Conclusion Sex does not affect clinical outcomes after PCI for complex lesions. PCI outcomes, however, may be adversely affected by height.

Bioresorbable vascular scaffold Korean expert panel report

Bioresorbable vascular scaffold (BRS) is an innovative device that provides structural support and drug release to prevent early recoil or restenosis, and then degrades into nontoxic compounds to avoid late complications related with metallic drug-eluting stents (DESs). BRS has several putative advantages. However, recent randomized trials and registry studies raised clinical concerns about the safety and efficacy of first generation BRS. In addition, the general guidance for the optimal practice with BRS has not been suggested due to limited long-term clinical data in Korea. To address the safety and efficacy of BRS, we reviewed the clinical evidence of BRS implantation, and suggested the appropriate criteria for patient and lesion selection, scaffold implantation technique, and management.

Formation and transformation of neointima after drug-eluting stent implantation: Insights from optical coherence tomographic studies

After coronary stent implantation, neointima formation resembles the wound healing process as it involves the sequential processes of inflammation, granulation, and remodeling. Because antiproliferative drugs and polymers of drug-eluting stents (DESs) delay vascular healing compared with bare metal stents, fibrin deposition can remain long after stent implantation, or inflammation can be excessive. Delayed vascular healing can be associated with adverse clinical outcomes including DES thrombosis or restenosis, and poor endothelization of DES neointima can accelerate neoatherosclerotic change inside the neointima, further contributing to luminal restenosis or neointimal instability. Despite the lack of correlation between pathologic and optical coherence tomography (OCT) findings, OCT assessments of neointima under various circumstances can reveal vascular responses to stent therapy. Homogeneous, heterogeneous, and layered neointima patterns can be recognized by OCT and can change with time. Homogeneous neointima might be associated with better clinical outcomes after DES implantation, whereas non-homogeneous neointima or neoatherosclerotic change can be associated with poorer clinical outcomes. However, limited data are currently available, and further studies are required to comprehensively address these questions.

Clinical Implication of Optical Coherence Tomography-Based Neoatherosclerosis

Recent research has indicated neoatherosclerosis (NA), the de novo development of atherosclerosis within the neointimal region of the stented segment after coronary stent implantation, as a mechanism of late/very late stent thrombosis (VLST) and restenosis. This research is based on histologic and intravascular imaging studies. Optical coherence tomography (OCT) is an imaging tool that is superior with regard to resolution capacity, and can be used to visualize detailed information about distinct morphological characteristics of the restenotic tissue. Thus, OCT is a valuable imaging tool for examining NA, such as macrophage infiltration, lipid accumulation, in-stent calcification, or neointimal rupture. This article discusses the prevalence, predictors, and clinical implications of NA that can be observed by OCT.

OPTICAL COHERENCE TOMOGRAPHY–BASED EVALUATION OF IN–STENT NEOATHEROSCLEROSIS IN LESIONS WITH MORE THAN 50% OF PERCENT NEOINTIMAL CROSS–SECTIONAL AREA STENOSIS

Atherosclerotic changes within in–stent neointimal tissue, which might be considered as a mechanism of late stent failure, have not been sufficiently investigated. Neointimal characteristics of 152 lesions (128 drug–eluting stents [DESs] and 24 bare–metal stents [BMSs]) with >50% of percent