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Purpose: Many studies have proposed predictive models for type 2 diabetes mellitus (T2DM). However, these predictive models have several limitations, such as user convenience and reproducibility. The purpose of this study was to develop a T2DM predictive model using electronic medical records (EMRs) and machine learning and to compare the performance of this model with traditional statistical methods. Materials and Methods: In this study, a total of available 8454 patients who had no history of diabetes and were treated at the cardiovascular center of Korea University Guro Hospital were enrolled. All subjects completed 5 years of follow up. The prevalence of T2DM during follow up was 4.78% (404/8454). A total of 28 variables were extracted from the EMRs. In order to verify the crossvalidation test according to the prediction model, logistic regression (LR), linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and K-nearest neighbor (KNN) algorithm models were generated. The LR model was considered as the existing statistical analysis method. Results: All predictive models maintained a change within the standard deviation of area under the curve (AUC) <0.01 in the analysis after a 10-fold cross-validation test. Among all predictive models, the LR learning model showed the highest prediction performance, with an AUC of 0.78. However, compared to the LR model, the LDA, QDA, and KNN models did not show a statistically significant difference. Conclusion: We successfully developed and verified a T2DM prediction system using machine learning and an EMR database, and it predicted the 5-year occurrence of T2DM similarly to with a traditional prediction model. In further study, it is necessary to apply and verify the prediction model through clinical research. [ABSTRACT FROM AUTHOR]

Purpose: Many recent studies have reported that successful percutaneous coronary intervention (PCI) with drug-eluting stents (DESs) for chronic total occlusion (CTO) has more beneficial effects than failed CTO-PCI; however, there are only limited data available from comparisons of successful CTO-PCI with medical therapy (MT) in the Korean population. Materials and Methods: A total of 840 consecutive CTO patients who underwent diagnostic coronary angiography, receiving either PCI with DESs or MT, were enrolled. Patients were divided into two groups according to the treatment assigned. To adjust for potential confounders, propensity score matching (PSM) analysis was performed using logistic regression. Individual major clinical outcomes and major adverse cardiac events, a composite of total death, myocardial infarction (MI), stroke, and revascularization, were compared between the two groups up to 5 years. Results: After PSM, two propensity-matched groups (265 pairs, n=530) were generated, and the baseline characteristics were balanced. Although the PCI group showed a higher incidence of target lesion and vessel revascularization on CTO, the incidence of MI tended to be lower [hazard ratio (HR): 0.339, 95% confidence interval (CI): 0.110 to 1.043, p=0.059] and the composite of total death or MI was lower (HR: 0.454, 95% CI: 0.224 to 0.919, p=0.028), compared with the MT group up to 5 years. Conclusion: In this study, successful CTO PCI with DESs was associated with a higher risk of repeat PCI for the target vessel, but showed a reduced incidence of death or MI. [ABSTRACT FROM AUTHOR]

Purpose: Prediabetes is an independent risk factor for cardiovascular disease. However, data on the long term adverse clinical outcomes of prediabetic patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stents (DESs) are scarce. Materials and Methods: The study population comprised 674 consecutive non-diabetic patients who underwent elective PCI between April 2007 and November 2010. Prediabetes was defined as hemoglobin A1c (HbA1c) of 5.7% to 6.4%. Two-year cumulative clinical outcomes of prediabetic patients (HbA1c of 5.7% to 6.4%, n=242) were compared with those of a normoglycemic group (<5.7%, n=432). Results: Baseline clinical and angiographic characteristics were similar between the two groups, except for higher glucose levels (104.8±51.27 mg/dL vs. 131.0±47.22 mg/dL, p<0.001) on admission in the prediabetes group. There was no significant difference between the two groups in coronary angiographic parameters, except for a higher incidence of diffuse long lesion in the prediabetes group. For prediabetic patients, trends toward higher incidences of binary restenosis (15.6% vs. 9.8 %, p=0.066) and late loss (0.71±0.70 mm vs. 0.59±0.62 mm, p=0.076) were noted. During the 24 months of follow up, the incidence of mortality in prediabetic patients was higher than that in normoglycemic patients (5.5% vs. 1.5%, p=0.007). Conclusion: In our study, a higher death rate and a trend toward a higher incidence of restenosis in patients with prediabetes up to 2 years, compared to those in normoglycemic patients, undergoing elective PCI with contemporary DESs. [ABSTRACT FROM AUTHOR]

Purpose: Differences in the utility of routine angiographic follow-up (RAF) and clinical follow-up (CF) after percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) are not well understood. The present study aimed to compare the 3-year clinical outcomes of RAF and CF in AMI patients who underwent PCI with drug-eluting stents (DES). Materials and Methods: A total of 774 consecutive AMI patients who underwent PCI with DES were enrolled. RAF was performed at 6 to 9 months after index PCI (n=425). The remaining patients were medically managed and clinically followed (n=349); symptom-driven events were captured. To adjust for any potential confounders, a propensity score matched analysis was performed using a logistic regression model, and two propensity-matched groups (248 pairs, n=496, C-statistic=0.739) were generated. Cumulative clinical outcomes up to 3 years were compared between RAF and CF groups. Results: During the 3-year follow-up period, the cumulative incidences of revascularization [target lesion revascularization: hazard ratio (HR), 2.40; 95% confidence interval (CI), 1.18-4.85; p=0.015, target vessel revascularization (TVR): HR, 3.33; 95% CI, 1.69-6.58; p=0.001, non-TVR: HR, 5.64; 95% CI, 1.90-16.6; p=0.002] and major adverse cardiac events (MACE; HR, 3.32; 95% CI, 1.92-5.73; p<0.001) were significantly higher in the RAF group than the CF group. However, the 3-year incidences of death and myocardial infarction were not different between the two groups. Conclusion: RAF following index PCI with DES in AMI patients was associated with increased incidences of revascularization and MACE. Therefore, CF seems warranted for asymptomatic patients after PCI for AMI. [ABSTRACT FROM AUTHOR]

Purpose: Transradial intervention (TRI) shows anatomical and technical differences between the right radial approach (RRA) and left radial approach (LRA). The aim of this study was to evaluate the efficacy and safety using LRA, compared with RRA. Materials and Methods: A total of 1653 consecutive patients who underwent TRI from November 2004 to October 2010 were enrolled in the Korean multicenter TRI registry. The patients were divided into two groups: the RRA group (n=792 patients) and the LRA group (n=861 patients). To adjust for any potential confounders, propensity score matched (PSM) analysis was performed (C-statistic: 0.726). After PSM, a total of 1100 patients were enrolled for analysis. Results: After PSM, the RRA group exhibited a larger contrast volume (259.3±119.6 mL vs. 227.0±90.7 mL, p<0.001), a longer fluoroscopic time (22.5±28.0 minutes vs. 17.1±12.6 minutes) and higher access site change (12.3% vs. 1.0%, p<0.001) than the LRA group. Meanwhile, the LRA group showed a shorter procedure time (49.2±30.4 minutes vs. 55.4±28.7 minutes, p=0.003) than the RRA group. After PSM, in-hospital complications and 12-month cumulative clinical outcomes were similar between the two groups. Conclusion: Of the two TRI methods, LRA was associated with better procedural efficacy, including shorter procedural time, smaller contrast volume, and less access site change than RRA. However, both methods showed similar 12-month cumulative clinical outcomes. Therefore, LRA was deemed superior to RRA in terms of procedural feasibility without a significant difference in clinical outcomes. [ABSTRACT FROM AUTHOR]

Purpose: Calcium channel blockers diltiazem and nitrate have been used as selective coronary vasodilators for patients with significant coronary artery spasm (CAS). However, no study has compared the efficacy of diltiazem alone versus diltiazem with nitrate for long-term clinical outcomes in patients with CAS. Materials and Methods: A total of 2741 consecutive patients without significant coronary artery disease with positive CAS by acetylcholine (Ach) provocation test between November 2004 and May 2014 were enrolled. Significant CAS was defined as a narrowing of >70% by incremental intracoronary injection of 20, 50, and 100 µg of Ach into the left coronary artery. Patients were assigned to either the diltiazem group (n=842) or the dual group (diltiazem with nitrate, n=1899) at physician discretion. To adjust for potential confounders, a propensity score matching (PSM) analysis was performed using the logistic regression model. After PSM analysis, two well-balanced groups (811 pairs, n=1622, C-statistic=0.708) were generated. Results: At 5 years, there were similar incidences in primary endpoints, including mortality, myocardial infarction, revascularization, and recurrent angina requiring repeat coronary angiography between the two groups. Diltiazem alone was not an independent predictor for major adverse cardiovascular events or recurrent angina requiring repeat coronary angiography. Conclusion: Despite the expected improvement of endothelial function and the relief of CAS, the combination of diltiazem and nitrate treatment was not superior to diltiazem alone in reducing mortality and cardiovascular events up to 5 years in patients with significant CAS. [ABSTRACT FROM AUTHOR]

Purpose: Angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) are associated with a decreased incidence of new-onset diabetes mellitus (NODM). The aim of this study was to compare the protective effect of ACEI versus ARBs on NODM in an Asian population. Materials and Methods: We investigated a total of 2817 patients who did not have diabetes mellitus from January 2004 to September 2009. To adjust for potential confounders, a propensity score matched (PSM) analysis was performed using a logistic regression model. The primary end-point was the cumulative incidence of NODM, which was defined as having a fasting blood glucose ≥126 mg/dL or HbA1c ≥6.5%. Multivariable cox-regression analysis was performed to determine the impact of ACEI versus ARB on the incidence of NODM. Results: Mean follow-up duration was 1839±1019 days in all groups before baseline adjustment and 1864±1034 days in the PSM group. After PSM (C-statistics=0.731), a total 1024 patients (ACEI group, n=512 and ARB group, n=512) were enrolled for analysis and baseline characteristics were well balanced. After PSM, the cumulative incidence of NODM at 3 years was lower in the ACEI group than the ARB group (2.1% vs. 5.0%, p=0.012). In multivariate analysis, ACEI vs. ARB was an independent predictor of the lower incidence for NODM (odd ratio 0.37, confidence interval 0.17–0.79, p=0.010). Conclusion: In the present study, compared with ARB, chronic ACEI administration appeared to be associated with a lower incidence of NODM in a series of Asian cardiovascular patients. [ABSTRACT FROM AUTHOR]

Purpose: High sensitive C-reactive protein (hs CRP) is well known as a strong risk factor of cardiovascular disease (CVD). The aim of this study is to evaluate the impact of elevated hs CRP on coronary artery spasm (CAS) as assessed by in-tracoronary acetylcholine (ACh) provocation test. Materials and Methods: A total of 1729 consecutive patients without significant CVD who underwent coronary angiography and intracoronary ACh test between November 2004 and August 2010 were analyzed. The patients were divided into five groups according to quintiles of hs CRP levels. Results: At baseline, the prevalence of elderly, hypertension, diabetes mellitus, current smoking, and lipid levels were higher in patients with higher hs CRP. During ACh test, the incidences of significant CAS, ischemic elec-trocardiography (EKG) change, multivessel, and diffuse CAS were higher in patients with higher hs CRP. Multivariate analysis showed that the old age (OR=1.01, CI; 1.0-1.02,p=0.0226), myocardial bridge (OR=3.34, CI; 2.16-5.17, p<0.001), and highest quintile hs CRP (OR=1.54, CI; 1.12-2.18,p=0.008) were independent predictors of ACh induced CAS. However, there was no difference in clinical outcomes up to 12 months. Conclusion: In conclusion, higher hs CRP was associated with higher incidence of CAS, worse angiographic characteristics and ischemic EKG change, but was not associated with clinical outcomes. [ABSTRACT FROM AUTHOR]