Although percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has been increasing in recent years, CTO PCI is still one of the most challenging procedures with relatively higher rates of procedural complications and adverse clinical events after PCI. Due to the innate limitations of invasive coronary angiography, intravascular imaging (IVI) has been used as an adjunctive tool to complement PCI, especially in complex coronary artery disease. Considering the complexity of CTO lesions, the role of IVI is particularly important in CTO intervention. IVI has been a useful adjunctive tool in every step of CTO PCI including assisted wire crossing, confirmation of wire location within CTO segment, and stent optimization. The meticulous use of IVI has been one of the greatest contributors to recent progress of CTO PCI. Nevertheless, studies evaluating the role of IVI during CTO PCI are limited. The current review provides a comprehensive overview of the mechanistic advantages of IVI in CTO PCI, summarizes previous studies and trials, and presents future perspective of IVI in CTO PCI.

Background: This study aimed to analyze the prehospital process and reperfusion therapy process of acute ischemic stroke in Busan metropolitan area and examine the impact of living arrangement on the early management and functional outcomes of acute ischemic stroke (AIS). Methods: The patients who diagnosed with AIS and received reperfusion therapy at the Busan Regional Cardiovascular Center between September 2020 and May 2023 were selected. We investigated the patients’ hospital arrival time (onset to door time) and utilization of 119 emergency ambulance services. Additionally, various time matrices related to reperfusion therapy after hospital were examined, along with the functional outcome at the 90-day after treatment. Results: Among the 753 AIS patients who underwent reperfusion therapy, 166 individuals (22.1%) were living alone. AIS patients living alone experienced significant delays in symptom detection (p<0.05) and hospital arrival compared to AIS patients with cohabitants (370.1 minutes vs. 210.2 minutes, p<0.001). There were no significant differences between the two groups in terms of 119 ambulance utilization and time metrics related with the reperfusion therapy. Independent predictors of prognosis in AIS patients were found to be age above 70, National Institutes of Health Stroke Scale score at admission, tissue plasminogen activator, living alone (odds ratio [OR], 1.785; 95% confidence interval [CI], 1.155–2.760) and interhospital transfer (OR, 1.898; 95% CI, 1.152–3.127). Delay in identification of AIS was shown significant correlation (OR, 2.440; 95% CI, 1.070–5.561) at living alone patients. Conclusion This study revealed that AIS patients living alone in the Busan metropolitan region, requiring endovascular treatment, face challenges in the pre-hospital phase, which significantly impact their prognosis.

Background/Aims: While switching strategies of P2Y12 receptor inhibitors (RIs) have sometimes been used in acute myocardial infarction (AMI) patients, the current status of in-hospital P2Y12RI switching remains unknown. Methods: Overall, 8,476 AMI patients who underwent successful revascularization from Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH) were divided according to in-hospital P2Y12RI strategies, and net adverse cardiovascular events (NACEs), defined as a composite of cardiac death, non-fatal myocardial infarction (MI), stroke, or thrombolysis in myocardial infarction (TIMI) major bleeding during hospitalization were compared. Results: Patients with in-hospital P2Y12RI switching accounted for 16.5%, of which 867 patients were switched from clopidogrel to potent P2Y12RI (C-P) and 532 patients from potent P2Y12RI to clopidogrel (P-C). There were no differences in NACEs among the unchanged clopidogrel, the unchanged potent P2Y12RIs, and the P2Y12RI switching groups. However, compared to the unchanged clopidogrel group, the C-P group had a higher incidence of non-fatal MI, and the P-C group had a higher incidence of TIMI major bleeding. In clinical events of in-hospital P2Y12RI switching, 90.9% of non-fatal MI occurred during pre-switching clopidogrel administration, 60.7% of TIMI major bleeding was related to pre-switching P2Y12RIs, and 71.4% of TIMI major bleeding was related to potent P2Y12RIs. Only 21.6% of the P2Y12RI switching group switched to P2Y12RIs after a loading dose (LD); however, there were no differences in clinical events between patients with and without LD. Conclusions In-hospital P2Y12RI switching occurred occasionally, but had relatively similar clinical outcomes compared to unchanged P2Y12RIs in Korean AMI patients. Non-fatal MI and bleeding appeared to be mainly related to pre-switching P2Y12RIs.

Background: Although ticagrelor is known to increase the bleeding risk compared to clopidogrel in East Asian patients, its clinical benefits in patients with acute myocardial infarction (AMI) without high bleeding risk (HBR) remains unknown. Methods: A total of 7,348 patients who underwent successful percutaneous coronary intervention (PCI) from the Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH), between November 2011 and December 2015, were divided into two groups according to the Academic Research Consortium for HBR criteria (KAMIR-HBR, 2,469 patients; KAMIR-non HBR, 4,879 patients). We compared in-hospital major adverse cardiovascular events (MACEs, defined as a composite of cardiac death, non-fatal myocardial infarction, or stroke), and the thrombolysis in myocardial infarction (TIMI) major bleeding between ticagrelor and clopidogrel in the KAMIR-HBR and the KAMIR-non HBR groups, respectively. Results: After propensity score matching, ticagrelor had a higher incidence of in-hospital TIMI major bleeding than clopidogrel in all patients (odds ratio [OR], 1.683; 95% confidence interval [CI], 1.010–2.805; P = 0.046) and the KAMIR-HBR group (OR, 3.460; 95% CI, 1.374–8.714; P = 0.008). However, there was no significant difference in in-hospital TIMI major bleeding between ticagrelor and clopidogrel in the KAMIR-non HBR group (OR, 1.436; 95% CI, 0.722–2.855; P = 0.303). No differences were observed in the cumulative incidences of in-hospital and 6-month MACEs between ticagrelor and clopidogrel in both groups. Conclusions The bleeding risk of ticagrelor was attenuated in Korean patients with AMI without HBR. Appropriate patient selection could reduce in-hospital bleeding complications associated with ticagrelor in Korean patients with AMI who underwent successful PCI.

BACKGROUND AND OBJECTIVES: Although complete revascularization is known superior to incomplete revascularization in ST elevation myocardial infarction (STEMI) patients with multi-vessel coronary artery disease (MVCD), there are no definite instructions on the optimal timing of non-culprit lesions percutaneous coronary intervention (PCI). We compared 1-year clinical outcomes between 2 different complete multi-vessel revascularization strategies.METHODS: From the Korea Acute Myocardial Infarction Registry-National Institute of Health, 606 patients with STEMI and MVCD who underwent complete revascularization were enrolled from November 2011 to December 2015. The patients were assigned to multi-vessel single-staged PCI (SS PCI) group (n=254) or multi-vessel multi-staged PCI (MS PCI) group (n=352). Propensity score matched 1-year clinical outcomes were compared between the groups.RESULTS: At one year, MS PCI showed a significantly lower rate of all-cause mortality (hazard ratio [HR], 0.42; 95% confidential interval [CI], 0.19–0.92; p=0.030) compared with SS PCI. In subgroup analysis, all-cause mortality increased in SS PCI with cardiogenic shock (HR, 4.60; 95% CI, 1.54–13.77; p=0.006), age ≥65 years (HR, 4.00; 95% CI, 1.67–9.58, p=0.002), Killip class III/IV (HR, 7.32; 95% CI, 1.68–31.87; p=0.008), and creatinine clearance ≤60 mL/min (HR, 2.81; 95% CI, 1.10–7.18; p=0.031). After propensity score-matching, MS PCI showed a significantly lower risk of major adverse cardiovascular event than SS PCI.CONCLUSIONS: SS PCI was associated with worse clinical outcomes compared with MS PCI. MS PCI for non-infarct-related artery could be a better option for patients with STEMI and MVCD, especially high-risk patients.
Arteries ; Coronary Artery Disease ; Coronary Vessels ; Creatinine ; Humans ; Korea ; Mortality ; Myocardial Infarction ; Myocardial Revascularization ; Percutaneous Coronary Intervention ; Propensity Score ; Shock, Cardiogenic

Background/Aims: Minimising total ischemic time (TIT) is important for improving clinical outcomes in patients with ST-segment elevation myocardial infarction who have undergone percutaneous coronary intervention (PCI). TIT has not shown a significant improvement due to persistent pre-hospital delay. This study aimed to investigate the risk factors associated with pre-hospital delay. Methods: Individuals enrolled in the Korea Acute Myocardial Infarction Registry-National Institutes of Health between 2011 and 2015 were included in this study. The study population was analyzed according to the symptom-to-door time (STDT; within 60 or > 60 minutes), and according to the type of hospital visit (emergency medical services [EMS], non-PCI center, or PCI center). Results: A total of 4,874 patients were included in the analysis, of whom 28.4% arrived at the hospital within 60 minutes of symptom-onset. Old age (> 65 years), female gender, and renewed ischemia were independent predictors of delayed STDT. Utilising EMS was the only factor shown to reduce STDT within 60 minutes, even when cardiogenic shock was evident. The overall frequency of EMS utilisation was low (21.7%). Female gender was associated with not utilising EMS, whereas cardiogenic shock, previous myocardial infarction, familial history of ischemic heart disease, and off-hour visits were associated with utilising EMS. Conclusions Factors associated with delayed STDT and not utilising EMS could be targets for preventive intervention to improve STDT and TIT.

BACKGROUND AND OBJECTIVES: There is a paucity of data regarding the benefit of clopidogrel monotherapy after dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents (DES). This study compared outcome between clopidogrel versus aspirin as monotherapy after DES for acute myocardial infarction (MI). METHODS: From Korea Acute Myocardial Infarction Registry-National Institute of Health database, 1,819 patients treated with DES who were switched to monotherapy with clopidogrel (n=534) or aspirin (n=1,285) after uneventful 12-month DAPT were analyzed. The primary endpoint was net adverse clinical events (NACE), defined as a composite of death from any cause, MI, repeat percutaneous coronary intervention (PCI), stent thrombosis, ischemic stroke, or major bleeding during the period from 12 to 24 months. RESULTS: After adjustment using inverse probability of treatment weighting, patients who received clopidogrel, compared with those treated with aspirin, had a similar incidence of NACE (0.7% and 0.7%; hazard ratio, 1.06; 95% confidence interval, 0.31–3.60; p=0.923). The 2 groups had similar rates of death from any cause (0.1% in each group, p=0.789), MI (0.3% and 0.1%, respectively; p=0.226), repeat PCI (0.1% and 0.3%, respectively; p=0.548), stent thrombosis (0.1% and 0%, respectively; p=0.121), major bleeding (0.2% in each group, p=0.974), and major adverse cardiovascular and cerebrovascular events (0.5% in each group, p=0.924). CONCLUSIONS Monotherapy with clopidogrel, compared to aspirin, after DAPT showed similar clinical outcomes in patients with acute MI treated with DES.

BACKGROUND AND OBJECTIVES: Although complete revascularization is known superior to incomplete revascularization in ST elevation myocardial infarction (STEMI) patients with multi-vessel coronary artery disease (MVCD), there are no definite instructions on the optimal timing of non-culprit lesions percutaneous coronary intervention (PCI). We compared 1-year clinical outcomes between 2 different complete multi-vessel revascularization strategies. METHODS: From the Korea Acute Myocardial Infarction Registry-National Institute of Health, 606 patients with STEMI and MVCD who underwent complete revascularization were enrolled from November 2011 to December 2015. The patients were assigned to multi-vessel single-staged PCI (SS PCI) group (n=254) or multi-vessel multi-staged PCI (MS PCI) group (n=352). Propensity score matched 1-year clinical outcomes were compared between the groups. RESULTS: At one year, MS PCI showed a significantly lower rate of all-cause mortality (hazard ratio [HR], 0.42; 95% confidential interval [CI], 0.19–0.92; p=0.030) compared with SS PCI. In subgroup analysis, all-cause mortality increased in SS PCI with cardiogenic shock (HR, 4.60; 95% CI, 1.54–13.77; p=0.006), age ≥65 years (HR, 4.00; 95% CI, 1.67–9.58, p=0.002), Killip class III/IV (HR, 7.32; 95% CI, 1.68–31.87; p=0.008), and creatinine clearance ≤60 mL/min (HR, 2.81; 95% CI, 1.10–7.18; p=0.031). After propensity score-matching, MS PCI showed a significantly lower risk of major adverse cardiovascular event than SS PCI. CONCLUSIONS SS PCI was associated with worse clinical outcomes compared with MS PCI. MS PCI for non-infarct-related artery could be a better option for patients with STEMI and MVCD, especially high-risk patients.

BACKGROUND AND OBJECTIVES: There is a paucity of data regarding the benefit of clopidogrel monotherapy after dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents (DES). This study compared outcome between clopidogrel versus aspirin as monotherapy after DES for acute myocardial infarction (MI).METHODS: From Korea Acute Myocardial Infarction Registry-National Institute of Health database, 1,819 patients treated with DES who were switched to monotherapy with clopidogrel (n=534) or aspirin (n=1,285) after uneventful 12-month DAPT were analyzed. The primary endpoint was net adverse clinical events (NACE), defined as a composite of death from any cause, MI, repeat percutaneous coronary intervention (PCI), stent thrombosis, ischemic stroke, or major bleeding during the period from 12 to 24 months.RESULTS: After adjustment using inverse probability of treatment weighting, patients who received clopidogrel, compared with those treated with aspirin, had a similar incidence of NACE (0.7% and 0.7%; hazard ratio, 1.06; 95% confidence interval, 0.31–3.60; p=0.923). The 2 groups had similar rates of death from any cause (0.1% in each group, p=0.789), MI (0.3% and 0.1%, respectively; p=0.226), repeat PCI (0.1% and 0.3%, respectively; p=0.548), stent thrombosis (0.1% and 0%, respectively; p=0.121), major bleeding (0.2% in each group, p=0.974), and major adverse cardiovascular and cerebrovascular events (0.5% in each group, p=0.924).CONCLUSIONS: Monotherapy with clopidogrel, compared to aspirin, after DAPT showed similar clinical outcomes in patients with acute MI treated with DES.
Aspirin ; Drug-Eluting Stents ; Hemorrhage ; Humans ; Incidence ; Korea ; Myocardial Infarction ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors ; Stents ; Stroke ; Thrombosis

Background: Observational studies of the ongoing coronavirus disease 2019 (COVID-19) outbreak suggest that a ‘cytokine storm’ is involved in the pathogenesis of severe illness.However, the molecular mechanisms underlying the altered pathological inflammation in COVID-19 are largely unknown. We report here that toll-like receptor (TLR) 4-mediated inflammatory signaling molecules are upregulated in peripheral blood mononuclear cells (PBMCs) from COVID-19 patients, compared with healthy controls (HC). Methods: A total of 48 subjects including 28 COVID-19 patients (8 severe/critical vs. 20 mild/ moderate cases) admitted to Chungnam National University Hospital, and age/sex-matched 20 HC were enrolled in this study. PBMCs from the subjects were processed for nCounter Human Immunology gene expression assay to analyze the immune related transcriptome profiles. Recombinant proteins of severe acute respiratory syndrome coronavirus-2 (SARSCoV-2) were used to stimulate the PBMCs and monocyte-derived macrophages, and real-time polymerase chain reaction was performed to quantify the mRNA expressions of the proinflammatory cytokines/chemokines. Results: Among the most highly increased inflammatory mediators in severe/critically ill patients, S100A9, an alarmin and TLR4 ligand, was found as a noteworthy biomarker, because it inversely correlated with the serum albumin levels. We also observed that recombinant S2 and nucleocapsid proteins of SARS-CoV2 significantly increased proinflammatory cytokines/chemokines and S100A9 in human primary PBMCs. Conclusion These data support a link between TLR4 signaling and pathological inflammation during COVID-19 and contribute to develop therapeutic approaches through targeting TLR4-mediated inflammation.