Sung Gyun Ahn

Relationship of Epicardial Adipose Tissue by Echocardiography to Coronary Artery Disease

Objective: To study the relationship of echocardiographic epicardial adipose tissue (EAT) with coronary artery disease (CAD) risk factors and the extent of coronary atherosclerosis. Methods: EAT thickness was measured in 527 patients undergoing their first coronary angiography. EAT was defined as an echo-lucent area on the free wall of the right ventricle on the still image of the two-dimensional echocardiogram at end diastole in the parasternal long-axis and parasternal short-axis views. A CT scan at the umbilicus was acquired to measure abdominal visceral adipose tissue (VAT) from a random sample of 30 patients. The extent of coronary atherosclerosis was assessed using a coronary atherosclerosis score based on the quantitative coronary angiography results. Results: EAT thickness was correlated with abdominal VAT (rs = 0.626, p<0.001), age (rs = 0.480, p<0.001), waist circumference (rs = 0.309, p<0.001), body mass index (rs = 0.233, p<0.001), C reactive protein (rs = 0.224, p<0.001), and the homoeostasis model assessment score (rs = 0.249, p<0.001). EAT was thicker in subjects with CAD than in those without CAD (4.0 vs 1.5 mm, p<0.001). Patients with unstable angina had thicker EAT than those with stable angina or atypical chest pain (4.0, 3.0, and 1.5 mm, respectively, p<0.001). EAT (⩾3.0 mm) was an independent factor of CAD on multiple logistic analysis (odds ratio  =  3.357; 95% CI 2.177 to 5.175, p<0.001). Conclusions: These results suggest that EAT may reflect the amount of visceral fat, which is associated with insulin resistance and inflammation. The echocardiographic measurement of EAT may provide additional information for assessing CAD risk and predicting the extent and activity of CAD.

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.

Impact of Body Mass Index on the relationship of epicardial adipose tissue to metabolic syndrome and coronary artery disease in an Asian population

BackgroundIn a previous study, we demonstrated that the thickness of epicardial adipose tissue (EAT), measured by echocardiography, was increased in patients with metabolic syndrome (MS) and coronary artery disease (CAD). Several studies on obese patients, however, failed to demonstrate any relationship between EAT and CAD. We hypothesized that body mass index (BMI) affected the link between EAT and MS and CAD.MethodsWe consecutively enrolled 643 patients (302 males, 341 females; 59 ± 11 years), who underwent echocardiography and coronary angiography. The EAT thickness was measured on the free wall of the right ventricle at the end of diastole. All patients were divided into two groups: high BMI group, ≥27 kg/m2 (n = 165), and non-high BMI group, < 27 kg/m2 (n = 478).ResultsThe median and mean EAT thickness of 643 patients were 3.0 mm and 3.1 ± 2.4 mm, respectively. In the non-high BMI group, the median EAT thickness was significantly increased in patients with MS compared to those without MS (3.5 vs. 1.9 mm, p < 0.001). In the high BMI group, however, there was no significant difference in the median EAT thickness between patients with and without MS (3.0 vs. 2.5 mm, p = 0.813). A receiver operating characteristic (ROC) curve analysis predicting MS revealed that the area under the curve (AUC) of the non-high BMI group was significantly larger than that of the high BMI group (0.659 vs. 0.506, p = 0.007). When compared to patients without CAD, patients with CAD in both the non-high and high BMI groups had a significantly higher median EAT thickness (3.5 vs. 1.5 mm, p < 0.001 and 4.0 vs. 2.5 mm, p = 0.001, respectively). However, an ROC curve analysis predicting CAD revealed that the AUC of the non-high BMI group tended to be larger than that of the high BMI group (0.735 vs. 0.657, p = 0.055).ConclusionsWhile EAT thickness was significantly increased in patients with MS and CAD, the power of EAT thickness to predict MS and CAD was stronger in patients with BMI < 27 kg/m2. These findings showed that the measurement of EAT thickness by echocardiography might be especially useful in an Asian population with a non-high BMI, less than 27 kg/m2.

The ratio of serum leptin to adiponectin provides adjunctive information to the risk of metabolic syndrome beyond the homeostasis model assessment insulin resistance: The Korean Genomic Rural Cohort Study

BACKGROUND Leptin and adiponectin are adipokines, shown to have opposing functions for fat metabolism and development of metabolic syndrome. We determined if the ratio of serum leptin to adiponectin (L/A ratio) adjunctively contributes to the risk of metabolic syndrome beyond the homeostasis model assessment of insulin resistance (HOMA-IR). METHODS This study included 1532 men and 1856 women, aged 40-70 y assessed in the Korean Genomic Rural Cohort Study from 2005 to 2008. The serum concentrations of adiponectin and leptin were measured by radioimmunoassay. Area under the receiver operating characteristic curve (AUROC) analyses were used to describe the ability of L/A ratio and HOMA-IR to differentiate between subjects with and without metabolic syndrome. RESULTS There were no significant differences in the ability of L/A ratio and HOMA-IR to predict metabolic syndrome (AUROC of L/A ratio vs. HOMA-IR, 0.771 vs. 0.774, p=0.8006 for men; 0.677 vs. 0.691, p=0.3088 for women). There was a significant adjunctive contribution by the L/A ratio, beyond that of HOMA-IR, to the risk of metabolic syndrome in men (p<0.0001 with 0.028 increased AUROC) and women (p=0.025 with 0.017 increased AUROC). CONCLUSIONS The L/A ratio provides significant adjunctive information to the risk of metabolic syndrome beyond HOMA-IR alone. The L/A ratio could be a good surrogate marker to assess metabolic syndrome.

Clinical Feasibility of 3D Automated Coronary Atherosclerotic Plaque Quantification Algorithm on Coronary Computed Tomography Angiography: Comparison with Intravascular Ultrasound.

ObjectiveTo evaluate the diagnostic performance of automated coronary atherosclerotic plaque quantification (QCT) by different users (expert/non-expert/automatic).MethodsOne hundred fifty coronary artery segments from 142 patients who underwent coronary computed tomography angiography (CCTA) and intravascular ultrasound (IVUS) were analyzed. Minimal lumen area (MLA), maximal lumen area stenosis percentage (%AS), mean plaque burden percentage (%PB), and plaque volume were measured semi-automatically by expert, non-expert, and fully automatic QCT analyses, and then compared to IVUS.ResultsBetween IVUS and expert QCT analysis, the correlation coefficients (r) for the MLA, %AS, %PB, and plaque volume were excellent: 0.89 (p < 0.001), 0.84 (p < 0.001), 0.91 (p < 0.001), and 0.94 (p < 0.001), respectively. There were no significant differences in the mean parameters (all p values >0.05) except %AS (p = 0.01). The automatic QCT analysis showed comparable performance to non-expert QCT analysis, showing correlation coefficients (r) of the MLA (0.80 vs. 0.82), %AS (0.82 vs. 0.80), %PB (0.84 vs. 0.73), and plaque volume (0.84 vs. 0.79) when they were compared to IVUS, respectively.ConclusionFully automatic QCT analysis showed clinical utility compared with IVUS, as well as a compelling performance when compared with semiautomatic analyses.Key Points• Coronary CTA enables the assessment of coronary atherosclerotic plaque.• High-risk plaque characteristics and overall plaque burden can predict future cardiac events.• Coronary atherosclerotic plaque quantification is currently unfeasible in practice.• Quantitative computed tomography coronary plaque analysis software (QCT) enables feasible plaque quantification.• Fully automatic QCT analysis shows excellent performance.

Efficacy of Combination Treatment with Intracoronary Abciximab and Aspiration Thrombectomy on Myocardial Perfusion in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Coronary Stenting

Purpose We aimed to investigate whether combination therapy using intracoronary (IC) abciximab and aspiration thrombectomy (AT) enhances myocardial perfusion compared to each treatment alone in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Materials and Methods We enrolled 40 patients with STEMI, who presented within 6 h of symptom onset and had Thrombolysis in MI flow 0/1 or a large angiographic thrombus burden (grade 3/4). Patients were randomly divided into 3 groups: 10 patients who received a bolus of IC abciximab (0.25 mg/kg); 10 patients who received only AT; and 20 patients who received both treatments. The index of microcirculatory resistance (IMR) was measured with a pressure sensor/thermistor-tipped guidewire following successful PCI. Microvascular obstruction (MVO) was assessed using cardiac magnetic resonance imaging on day 5. Results IMR was lower in the combination group than in the IC abciximab group (23.5±7.4 U vs. 66.9±48.7 U, p=0.001) and tended to be lower than in the AT group, with barely missed significance (23.5±7.4 U vs. 37.2±26.1 U, p=0.07). MVO was observed less frequently in the combination group than in the IC abciximab group (18.8% vs. 88.9%, p=0.002) and tended to occur less frequently than in the AT group (18.8% vs. 66.7%, p=0.054). No difference of IMR and MVO was found between the IC abciximab and the AT group (66.9±48.7 U vs. 37.2±26.1 U, p=0.451 for IMR; 88.9% vs. 66.7%, p=0.525 for MVO, respectively). Conclusion Combination treatment using IC abciximab and AT may synergistically improve myocardial perfusion in patients with STEMI undergoing primary PCI (Trial Registration: clinicaltrials. gov Identifier: NCT01404507).

Multicenter randomized trial of 3-month cilostazol use in addition to dual antiplatelet therapy after biolimus-eluting stent implantation for long or multivessel coronary artery disease.

BACKGROUND There are conflicting data on the use of cilostazol as triple antiplatelet therapy (TAPT) for improving clinical outcomes after drug-eluting stent implantation. We aimed to evaluate whether 3-month use of cilostazol in addition to dual antiplatelet therapy (DAPT) improved clinical outcomes in patients with long or multivessel coronary artery disease (CAD) after biolimus-eluting stent (BES) implantation. METHODS Patients (n = 630) who had been successfully treated with BES implantation for lesions with ≥28 mm in stent length or ≥2 stents for different coronary arteries were enrolled in this prospective randomized multicenter trial. All patients were randomly assigned to receive either DAPT (aspirin and clopidogrel for 12 months, n = 314) or TAPT (DAPT plus 3-month cilostazol use, n = 316). The primary end point was a device-oriented composite consisting of cardiac death, myocardial infarction (not clearly attributable to a nontarget vessel), and ischemia-driven target lesion revascularization at 1-year follow-up. RESULTS A total of 314 patients in DAPT and 308 patients in TAPT were analyzed. Multivessel CAD was present in 65.7% of patients. Stents ≥28 mm in length were implanted in 58.1% of lesions. There were no significant differences in baseline and angiographic characteristics between the 2 groups. The primary end point was similar between the 2 groups (2.3% in DAPT vs 1.9% in TAPT, log-rank P = .799). CONCLUSIONS In patients treated with BES implantation for long or multivessel CAD, 3 months of cilostazol use in addition to DAPT did not improve clinical outcome at 1-year follow-up.

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.

Differential Relationship between Metabolic Syndrome Score and Severity of Coronary Atherosclerosis as Assessed by Angiography in a Non-Diabetic and Diabetic Korean Population

Whether the metabolic syndrome (MetS) has prognostic value for coronary artery disease (CAD) beyond its individual components is controversial. We compared the relationship between the number of MetS components and CAD severity as assessed by angiography in non-diabetic and diabetic subjects. We consecutively enrolled 527 patients who underwent their first coronary angiography. Patients were divided into four groups according to the number of MetS components: 0/1, 2, 3, and 4/5. A coronary atherosclerosis score was used to quantify the extent of atherosclerotic involvement. The relationship between the MetS score and angiographic CAD severity or clinical presentation was compared between non-diabetic and diabetic subjects. Individuals with the MetS (n = 327) had a higher prevalence of CAD (60% vs 32%, P < 0.001), multi-vessel disease (34% vs 16%, P < 0.001), and acute coronary syndromes (49% vs 26%, P < 0.001) than those without the MetS. In the non-diabetic group, atherosclerosis score increased with the MetS score (1.0 ± 2.1, 2.0 ± 2.9, 2.8 ± 2.9, and 3.6 ± 3.9, P < 0.001) whereas there was no significant difference in the diabetic group (0.5 ± 1.0, 5.2 ± 4.7, 4.2 ± 2.9, and 4.4 ± 3.5, P = 0.102). The MetS score is related to CAD severity in non-diabetic patients but the association between the MetS score and angiographic CAD severity may be obscured in the presence of diabetes.

Intravascular ultrasound-guided primary percutaneous coronary intervention with drug-eluting stent implantation in patients with ST-segment elevation myocardial infarction.

Studies investigating the clinical outcome of intravascular ultrasound (IVUS)‐guided primary percutaneous coronary intervention (PPCI) in patients with ST‐segment elevation myocardial infarction (STEMI) show conflicting results. The aim of our study was to evaluate whether IVUS‐guidedPPCI with drug‐eluting stents (DESs) in STEMI patients improves clinical outcome.