Kyung-Hoon Choe

Different prognostic significance of high on-treatment platelet reactivity as assessed by the VerifyNow P2Y12 assay after coronary stenting in patients with and without acute myocardial infarction.

OBJECTIVES This study compared the prognostic role of high on-treatment platelet reactivity (HTPR) in predicting thrombotic events in a Korean population undergoing percutaneous coronary intervention (PCI) in the acute myocardial infarction (AMI) and non-AMI setting. BACKGROUND The prognostic significance and optimal cutoff of HTPR might differ according to a given clinical condition, such as AMI and ethnicity. METHODS On-treatment platelet reactivity was measured with a VerifyNow P2Y12 assay (Accumetrics, San Diego, California) in 1,226 patients (824 men; age 65 ± 10 years), including 413 AMI cases, 12 to 24 h after PCI between March 2008 and March 2010. The prevalence of cardiovascular (CV) events defined as a composite of death from CV causes, nonfatal myocardial infarction, or stent thrombosis at 1-year follow-up were compared according to HTPR between patients with and without AMI. RESULTS The optimal cutoff for HTPR was 272 IU of the P2Y(12) reaction unit (PRU) (area under the curve: 0.708; 95% confidence interval [CI]: 0.607 to 0.809, p = 0.03), which was the upper-tertile threshold. Among AMI patients, 1-year CV events occurred more frequently in patients with versus without HTPR (n = 14 [8.8%] vs. n = 1 [0.4%], p < 0.001), whereas there was no difference in the composite endpoint on the basis of HTPR in patients without AMI (n = 7 [2.8%] vs. n = 8 [1.4%], p = 0.193). CONCLUSIONS Increased residual platelet reactivity is related to post-discharge CV events in subjects with AMI, whereas the prognostic significance of HTPR seems to be attenuated in patients with stable coronary disease after PCI.

Procedural outcomes of repeated transradial coronary procedure

We evaluated the changes in radial arterial diameter and the procedural outcomes of repeated transradial procedures through the same radial artery in 117 cases. No significant differences were found in the mean diameter of the radial artery between preprocedure and 1 day after procedure on initial and repeated procedures. However, the mean radial arterial diameter was significantly decreased from 2.63 ± 0.35 to 2.51 ± 0.29 mm during follow‐up after the initial procedure (P = 0.01). There was no significant difference in the vascular access times of the initial and repeated procedures (2.9 ± 3.1 vs. 3.3 ± 3.6 min; P = 0.08), and procedural success of repeated procedure was similar to those of the initial procedure. However, the incidence of radial arterial occlusion was higher for repeated procedures (2.6% vs. 0%; P = 0.01). We conclude that the repeated use of the radial artery is feasible in most patients with a high procedural success rate and low vascular complications. Cathet Cardiovasc Intervent 2003;58:301–304.

A case of transradial carotid stenting in a patient with total occlusion of distal abdominal aorta

We report a case with severe carotid stenosis in which carotid stenting was performed via the radial artery due to total occlusion of distal abdominal aorta. The radial approach offers a potential alternative in cases in which the femoral approach is problematic. Cathet Cardiovasc Intervent 2002;56:243–245.

Relationships between Serum Adiponectin with Metabolic Syndrome and Components of Metabolic Syndrome in Non-Diabetic Koreans: ARIRANG Study

Purpose Growing evidence suggests that hypoadiponectinemia may play a significant role in the development of metabolic syndrome (MetS). Therefore, the relationships between serum adiponectin with MetS and components of MetS were investigated in non-diabetic samples of drawn from the Koreans general population. Materials and Methods We performed a cross-sectional study in samples of older Koreans (age > 40 years) including 2,471 men and 3,463 women. MetS was defined according to the Asian modified criteria of the National Cholesterol Education Program Adult Treatment Panel III report. Serum adiponectin concentrations were measured by radioimmunoassay. Results The median adiponectin level in MetS was significantly lower than that in non-MetS subjects in men (6.00 vs. 8.00 µg/mL, p < 0.001) and women (10.12 vs. 11.74 µg/mL, p < 0.001). Adiponectin concentration was negatively correlated with waist circumference and levels of triglyceride, C-reactive protein (CRP), fasting glucose, and insulin, and positively correlated with high-density lipoprotein and age in both genders (p < 0.001). In a multivariate regression model after adjustment for age, body mass index, smoking, CRP, and lipid profiles, the odds ratio of MetS comparing extreme quartiles of adiponectin distribution was 0.32 [95% confidence interval (CI), 0.20 to 0.50] in men and 0.57 (95% CI, 0.43 to 0.76) in women. Conclusion Adiponectin levels are independently associated with the phenotype of MetS, as well as components of MetS in the non-diabetic Korean general population.

Feasibility of transradial coronary intervention using a sheathless guiding catheter in patients with small radial artery.

Background and Objectives Transradial coronary angiography and intervention are increasing in frequency due to lower major vascular access site complications and the potential for early mobilization. However, the small size of the radial artery (RA) is a major limitation of this technique. A sheathless guiding catheter (GC) has recently been introduced that has a 1-2 French smaller diameter compared with the corresponding introducer sheath. This catheter also has a hydrophilic coating along its entire length. We evaluated the feasibility of using a sheathless GC in patients who have small radial arteries. Subjects and Methods The procedural results were evaluated in patients with small radial arteries (diameter <2.3 mm) who underwent transradial coronary intervention using a sheathless GC. Results A total of 25 (male: 9) patients with 29 lesions were enrolled. The mean RA diameter was 1.81±0.26 mm. 44% of the patients had stable angina and 50.0% had acute coronary syndrome. The procedural success rate was 93.1%. Two patients (6.9%) had chronic total occlusive lesions that could not be crossed with a guide-wire despite good guiding support. An intravascular ultrasound could be used for all of the treated lesions. Multi-vessel intervention was performed in 29.2% of the patients. Two bifurcated lesions were treated with a kissing balloon technique, and one with a modified T-stenting technique. No catheter related complications were reported. Conclusion The use of a sheathless GC is feasible in patients with small radial arteries without catheter related complications.

The feasibility of percutaneous transradial coronary intervention for chronic total occlusion.

We evaluated the feasibility of the transradial coronary intervention (TRCI) in 85 consecutive patients with chronic total occlusion (CTO). Clinical, angiographic and procedural factors were compared between the success and failure groups. An overall success rate of 65.5% (57 of 87 lesions) was achieved with TRCI, and the most common cause of failure was an inability to pass the lesion with a guidewire. A multivariate analysis demonstrated that the most significant predictor of failure was the duration of occlusion (OR 1.064 per month, 95% CI 1.005 to 1.126, p = 0.03). The procedural success rate improved with use of new-generation hydrophilic guidewires. The 6 Fr guiding catheters were used in the majority of the 70 cases (81%). Five cases were crossed over to a femoral artery approach due to engagement failure of the guiding catheter into the coronary ostium because of severe subclavian tortuosity and stenosis in two cases, radial artery looping in one case, and poor guiding support in two cases. There were no major entry site complications. In conclusion, the radial artery might be a feasible vascular route in coronary interventions for CTO, with comparable procedural success and no access site complications.

Normative Values and Correlates of Mean Common Carotid Intima-Media Thickness in the Korean Rural Middle-aged Population: The Atherosclerosis RIsk of Rural Areas iN Korea General Population (ARIRANG) Study

Carotid intima-media thickness (CIMT) is considered as a surrogate marker for cardiovascular disease (CVD). We determined the normative value of CIMT and correlates of CVD risk factors and Framingham risk score (FRS) in Korean rural middle-aged population. We measured CIMT with a B-mode ultrasonography in 1,759 subjects, aged 40 to 70 yr, in a population-based cohort in Korea. A healthy reference sample (n = 433) without CVD, normal weight and normal metabolic parameters was selected to establish normative CIMT values. Correlates between CIMT and conventional CVD risk factors were assessed in the entire population. Mean values of CIMT (in mm) for healthy reference sample aged 40-49, 50-59, and 60-70 yr were 0.55, 0.59, and 0.66 for men and 0.48, 0.55, and 0.63 for women, respectively. In multivariate regression analysis, CIMT was correlated with older age, higher BMI, male gender, higher LDL-cholesterol level and history of diabetes mellitus. The mean CIMT was also correlated with FRS in both gender (r2 = 0.043, P < 0.01 for men; r2 = 0.142, P < 0.01 for women). We identified normative value of CIMT for the healthy Korean rural middle-aged population. The CIMT is associated with age, obesity, gender, LDL-cholesterol, diabetes mellitus and FRS.

Genotype- and Phenotype-Directed Personalization of Antiplatelet Treatment in Patients with Non-ST Elevation Acute Coronary Syndromes Undergoing Coronary Stenting

Background and Objectives We evaluated the effectiveness of genotype- and phenotype-directed individualization of P2Y12 inhibitors to decrease high on-treatment platelet reactivity (HOPR). Subjects and Methods Sixty-five patients undergoing percutaneous coronary intervention for non-ST elevation acute coronary syndromes were randomly assigned to genotype- or phenotype-directed treatment. All patients were screened for CYP2C19*2, *3, or *17 alleles by using the Verigene CLO assay (Nanosphere, Northbrook, IL, USA). The P2Y12 reaction unit (PRU) was measured using the VerifyNow P2Y12 assay (Accumetrics, San Diego, CA, USA). 21 CYP2C19 *2 or *3 carriers (65.6%) and 11 patients with HOPR (33.3%), defined as a PRU value ≥230, were given 90 mg ticagrelor twice daily; non-carriers and patients without HOPR were given 75 mg clopidogrel daily. The primary endpoint was the percentage of patients with HOPR after 30 days of treatment. Results PRU decreased following both genotype- and phenotype-directed therapies (242±83 vs. 109±90, p<0.001 in the genotype-directed group; 216±74 vs. 109±90, p=0.001 in the phenotype-directed group). Five subjects (16.2%) in the genotype-directed group and one (3.3%) in the phenotype-directed group had HOPR at day 30 (p=0.086). All patients with HOPR at the baseline who received ticagrelor had a PRU value of <230 after 30 days of treatment. Conversely, clopidogrel did not lower the number of patients with HOPR at the baseline. Conclusion Tailored antiplatelet therapy according to point-of-care genetic and phenotypic testing may be effective in decreasing HOPR after 30 days.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention Improves the Clinical Outcome in Patients Undergoing Multiple Overlapping Drug-Eluting Stents Implantation

Background and Objectives Stented segment length is a predictive factor for restenosis and stent thrombosis still in the drug-eluting stent (DES) era, and the benefit of routine intravascular ultrasound (IVUS) is still unclear. The aim of the present study was to investigate whether IVUS-guided percutaneous coronary intervention (PCI) improved the vascular outcomes as compared with conventional PCI in the treatment of diffuse coronary artery disease. Subjects and Methods From our registry database from January 2006 to May 2009, we identified 85 consecutive patients with de novo coronary lesions treated with at least 64 mm of multiple, overlapping DES. The 2-year rate of major adverse cardiovascular events (MACE), defined as the composite of cardiovascular death, non-fatal myocardial infarction, target lesion revascularization (TLR), or stent thrombosis, was compared according to the use of IVUS. Results The 2-year MACE rate was lower in the IVUS-guided group than that of the angiography-guided group (8% vs. 33.3%, p=0.005). The incidence of TLR was lower in patients with IVUS use than in those without IVUS use (0% vs. 27.8%, p<0.001). On Cox proportional hazard analysis, no IVUS use {hazard ratio (HR) 5.917, 95% confidence interval (CI) 1.037-33.770, p=0.045} and age (HR 1.097, 95% CI 1.006-1.138, p=0.032) were unfavorable predictors for the 2-year MACE. Conclusion The use of IVUS may improve the effectiveness and safety of multiple overlapping drug-eluting stenting for long, diffuse coronary lesions.

Urinary levels of 8-iso-prostaglandin f2α and 8-hydroxydeoxyguanine as markers of oxidative stress in patients with coronary artery disease.

Background and Objectives The objective of this study was to determine if urinary levels of 8-iso-prostaglandin F2α (8-iso-PGF2α) and 8-hydroxydeoxyguanine (8-OHdG) could be used as markers of the oxidative stress in significant coronary artery disease (CAD). Subjects and Methods We conducted a case-control study in 104 subjects assessed by coronary angiography with the following diagnoses: 35 consecutive cases of significant CAD and 69 cases of non-CAD with stable angina. We compared the urinary levels of 8-iso-PGF 2α and 8-OHdG, as measured by immunoassay between the 2 groups. Results History of hypertension was significantly higher and high density lipoprotein-cholesterol level significantly lower in the CAD group compared with those in the non-CAD group. Median levels of 8-iso-PGF2α were significantly higher in the CAD group compared with the non-CAD group (9.2 vs. 6.0 ng/mg, p=0.001). There were no significant differences in 8-OHdG values between the 2 groups. The odds ratio of 8-iso-PGF2α for CAD in the highest tertile compared with that in the lowest tertile was 7.39 (95% confidence interval; 1.71-31.91). There was no significant difference in median values of 8-iso-PGF2α between single- and multi-vessel CAD. Conclusion Urinary 8-iso-PGF 2α was independently associated with significant CAD in this case-control study.