Jin Soo Choi

Endothelial dysfunction, increased carotid artery intima-media thickness and pulse wave velocity, and increased level of inflammatory markers are associated with variant angina

BACKGROUND Endothelial dysfunction and vascular inflammation may be associated with variant angina (VA). Flow-mediated vasodilation (FMD), carotid artery intima-media thickness (IMT), and pulse wave velocity (PWV) are widely used as non-invasive modalities for evaluating atherosclerosis. METHODS AND RESULTS A total of 254 patients with chest pain were divided into three groups according to coronary angiogram (CAG) finding. There were 76 patients (VA group: 53.5+/-10.2 years, 41 males) with normal CAG with positive ergonovine-provocation test (EPT), 58 patients (control group: 55.3+/-8.7 years, 30 males) with normal CAG with negative EPT, and 120 patients with angiographically diagnosed coronary artery disease (CAD group: 56.3+/-9.7 years, 79 males). The level of FMD was lower in the VA group than in the control group (7.7+/-3.5% vs. 9.4+/-3.8%, p=0.014). Carotid IMT was higher in the VA group than in the control group (0.58+/-0.1 mm vs. 0.54+/-0.1 mm, p=0.029). The brachial-ankle PWV (baPWV) was higher in the VA group than in the control group (1445.3+/-211.8 cm/s vs. 1396.7+/-394.5 cm/s, p=0.020). The levels of monocyte cell counts was higher in patients of the VA group than in the other two groups (7545.7+/-2611.1/mm(3) vs. 6548.2+/-2156.4/mm(3) vs. 6740.9+/-1730.4/mm(3), p=0.015, respectively; monocyte cell counts: 657.2+/-242.6/mm(3) vs. 442.5+/-219.3/mm(3) vs. 490.0+/-172.0/mm(3), p=0.025). CONCLUSION VA is associated with endothelial dysfunction and increased carotid IMT, baPWV, and inflammatory markers.

The Association of Socioeconomic Status with Three-Year Clinical Outcomes in Patients with Acute Myocardial Infarction Who Underwent Percutaneous Coronary Intervention

The aim of this study was to evaluate whether the clinical outcomes were associated with socioeconomic status (SES) in patients with acute myocardial infarction (AMI) who underwent percutaneous coronary intervention (PCI). The author analyzed 2,358 patients (64.9 ± 12.3 yr old, 71.5% male) hospitalized with AMI between November 2005 and June 2010. SES was measured by the self-reported education (years of schooling), the residential address (social deprivation index), and the national health insurance status (medical aid beneficiaries). Sequential multivariable modeling assessed the relationship of SES factors with 3-yr major adverse cardiovascular events (MACEs) and mortality after the adjustment for demographic and clinical factors. During the 3-yr follow-up, 630 (26.7%) MACEs and 322 (13.7%) all-cause deaths occurred in 2,358 patients. In multivariate Cox proportional hazards regression modeling, the only lower education of SES variables was associated with MACEs (hazard ratio [HR], 1.41; 95% confidence interval [CI], 1.04-1.91) and mortality (HR, 1.93; 95% CI, 1.16-3.20) in the patients with AMI who underwent PCI. The study results indicate that the lower education is a significant associated factor to increased poor clinical outcomes in patients with AMI who underwent PCI. Graphical Abstract

Effects of combination therapy of statin and N-acetylcysteine for the prevention of contrast-induced nephropathy in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND Acute myocardial infarction (AMI) is a risk factor for contrast-induced nephropathy (CIN). We investigated whether pretreatment with statin, N-acetylcysteine (NAC) and sodium bicarbonate (NaHCO3) reduces the risk of CIN. METHODS We conducted a prospective trial and enrolled a total of 334 ST-segment elevation myocardial infarction (STEMI) patients. Patients were divided into four groups: Group I (statin 40mg), Group II (statin 80mg), Group III (statin 80mg plus NAC 1200mg) and Group IV (regimen of group III plus NaHCO3 154mEq/L). CIN was defined as ≥25% or ≥0.5mg/dL increase in serum creatinine from the baseline within the 72h after PCI. RESULTS CIN occurred in 72 (21.6%) patients. The incidence of CIN was the lowest in the group III (14.3%), and multivariate analysis showed the lower incidence of CIN in group III compared to Group I [odds ratio (OR) 0.29, 95% confidence interval (CI) 0.13-0.64, p=0.002]. Admission hyperglycemia [(AHG)>198mg/dL] (OR 2.20, 95% Cl 1.20-3.68, p=0.011) and the use of intra-aortic balloon pump (IABP) (OR 4.20, 95% CI 1.38-12.78, p=0.016) were independent predictors for CIN. The CIN (OR 9.00, 95% CI 1.30-62.06, p=0.026) was an independent predictor for in-hospital mortality. CONCLUSIONS Combination of high-dose statin plus NAC was associated with lower incidence of CIN in patients with STEMI who underwent primary PCI compared to statin only.

A Prediction Cost based Complexity Reduction Method for Bi-Prediction in High Efficiency Video Coding (HEVC)

In HEVC, the fast search method is used for reducing the complexity of the motion prediction procedure. It is consisted of the sub-sampled SAD which reduce the complexity of Sum of Absolute Differences(SAD) calculation and the simplified bi-prediction method which reduce the iterations of the uni-prediction for the bi-prediction. The computational complexity is largely decreased by the fast search method but the coding gain is also decreased. In this paper, the simplified bi-prediction is extended to compensate the performance loss and the prediction cost based complexity reduction methods are also proposed to reduce the complexity burden by the extended bi-prediction method. A prediction cost based complexity reduction method is consisted of early termination method for the extended bi-prediction and the bi-prediction skipping method. Compare with HM 6.0 references S/W, the average 0.42% of BD-bitrate is decreased by both the extended bi-prediction method and the prediction cost based complexity reduction methods with negligible increasement of the complexity.