Joong Kyung Sung

Clinical characteristics and prognostic factors of stress-induced cardiomyopathy

Background and Objectives Stress-induced cardiomyopathy (SCM) is characterized by a transient left ventricular (LV) dysfunction due to emotional and physical stress. There are limited data about the clinical characteristics in Korean patients. We sought to clarify the clinical features and prognosis in patients with SCM. Subjects and Methods We reviewed 39 cases diagnosed with SCM in a tertiary hospital. The SCM was diagnosed as: 1) no previous history of cardiac disease, 2) acute onset, 3) regional wall motion abnormality, typically in the takotsubo or inverted takotsubo shape by echocardiography, and 4) no significant stenosis in the coronary angiogram. We evaluated clinical characteristics, biomarkers, and prognosis. Results Mean age was 61.3±16.1 years (female 69%). The triggering factors were physical stress in 32 patients (82%) and emotional stress in 5 patients (13%). The initial symptom was dyspnea (n=18, 46%) rather than chest pain (n=10, 26%). An initial electrocardiogram (EKG) presented T-wave inversion (n=18, 46%), ST-elevation (n=11, 28%), and ST-depression (n=2, 5%). Multivariate logistic regression analysis showed that initial high sensitive C-reactive protein (hs-CRP) {odds ratio (OR) 1.41, 95% confidence interval (CI); 1.02-1.97} and initial left ventricular ejection fraction (LVEF) (OR 0.89, 95% CI; 0.80-0.98) were significantly associated with death or cardiogenic shock, respectively. Conclusion The major triggering factor of SCM is physical stress due to illness or surgical procedures, and the first manifestation is dyspnea rather than chest pain. Elevated hs-CRP and decreased LVEF at admission were independent risk factors for death or cardiogenic shock.

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.

A Case of Hypocalcemia-Induced Dilated Cardiomyopathy

Hypocalcemia is a rare cause of dilated cardiomyopathy. Hypocalcemia induced cardiomyopathy is usually reversible when calcium level returns to normal range. We experienced a case of 57-year-old woman who had suffered from hypocalcemia after total thyroidectomy and its consequence of dilated cardiomyopathy. After supplementation of calcium and vitamin D, symptoms of heart failure and LV function were recovered.

Urine Albumin Creatinine Ratio is Associated with Carotid Atherosclerosis in a Community Based Cohort: Atherosclerosis Risk of Rural Area in Korean General Population Study

Background Albuminuria is a surrogate marker of endothelial dysfunction and a predictor of cardiovascular events. Data are limited with regard to the relationship between albuminuria and subclinical atherosclerosis in a community-based cohort. We determined the association between albuminuria measured by the urine albumin creatinine ratio (UACR) and carotid intima media thickness (CIMT) in a Korean rural population. Methods We enrolled 1,369 healthy subjects older than 40 years (857 males and 518 females) with normal renal function and measured the CIMT. We excluded subjects with overt proteinuria (> 300 mg/day) or with treatment of diabetes mellitus, hypertension, dyslipidemia, and any cardiovascular disease. The subjects were stratified into the quartile value of the UACR (lowest quartile: UACR < 4.8 and highest quartile: UACR > 17.7). And we evaluate the relationship between UACR and CIMT by linear regression and logistic regression analysis. Results Increasing quartile of the UACR had a stepwise increase in body mass index, blood pressure, cholesterol profile [low density lipoprotein (LDL)-cholesterol and triglyceride], glucose, homeostratic model assessment of insulin resistance (HOMA-IR), and C-reactive protein (all p values < 0.001). Maximal CIMT from the 1st to the 4th quartile values of the UACR were 0.74 ± 0.17, 0.77 ± 0.18, 0.78 ± 0.18, and 0.82 ± 0.21 mm, respectively (p < 0.001). In a multivariate regression model adjusted for age, sex, systolic blood pressure, triglyceride, LDL-cholesterol, fasting blood sugar, waist circumference, adiponectin, HOMA-IR, high sensitive C-reactive protein, smoking, UACR showed a significant association with maximal CIMT (B = 0.014, R2 = 0.145, p = 0.002). Conclusion Albuminuria measured by the UACR was significantly associated with both CIMT and traditional risk factors of atherosclerosis except for smoking in healthy Koreans.

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.

Obesity and preclinical changes of cardiac geometry and function.

Overweight and obesity are rapidly increasing in prevalence due to adoption of the westernized life style in Korea. Obesity is strongly associated with the development of cardiovascular risk factors such as diabetes, hypertension, and dyslipidemia. In addition, accumulating evidence suggests that obesity per se has a direct effect on cardiac functional and structural changes that may not be the result of atherosclerosis. In this review, we focus on the view that obesity can influence on the structural and functional changes of the heart, drawing evidence from human and animal studies. We also review influencing factors such as physical, neurohormonal, and metabolic alterations that are associated with changes of the heart in obesity.

Intra-individual variability of residual platelet reactivity assessed by the VerifyNow-P2Y12 assay in patients with clopidogrel resistance after percutaneous coronary intervention.

We read with interest the study by Arméro el al. verifying large intra-individual variability in clopidogrel responsiveness assessed by the vasodilatorstimulated phosphoprotein (VASP) phosphorylation index in coronary artery disease patients on long-term clopidogrel therapy [1]. Results of the VASP phosphorylation assay were well correlated with those of the VeryfiNow P2Y12 point-of-care device (Accumetrics, San Diego, CA, USA) in subjects with acute coronary syndromes [2]. VASP phosphorylation assay is labor intensive and not routinely available. In contrast, the VerifyNow P2Y12 assay is rapid and easy to use. Thus, it has been increasingly used to measure residual platelet reactivity in patients taking clopidogrel [3, 4]. Individual variability of response to clopidogrel has been well recognized and there is growing evidence of an association of clopidogrel resistance with increased risk of thromboembolic events [5–9]. However, there has been yet no study on intra-individual variability of the VerifyNow P2Y12 assay. We conducted the present study to measure agreement of repeated VerifyNow P2Y12 reaction units (PRU) values over time in 50 (36 males, 14 females, 66 11 years) patients with low response to clopidogrel. These patients were derived from 507 patients who were tested with the VerifyNow P2Y12 assay after percutaneous coronary intervention (PCI) from January 2006 to December 2007 at our hospital. Low response to clopidogrel was defined as percent platelet inhibition less than or equal to 20% or PRU more than or equal to 235 IU [4]. The samples were collected at 1 month following PCI and 1 month after the initial measurement (mean time, 31 28 days; range, 16 62 days). Standard daily dual antiplatelet therapy (aspirin 100 mg and clopidogrel 75 mg) was maintained through the study. Agreement between the tests was assessed by the Spearman rank correlation and the Bland-Altman analyses. Baseline and follow-up PRU were 290.2 49.2 and 268.9 63.3, respectively. Initially, 43 of 50 (86%) patients were categorized into low response to clopidogrel in terms of both percentage platelet inhibition and PRU. At follow-up, only 36 of 50 patients (72%) were low responders fulfilling both definitions. There was a fair correlation between baseline and follow-up PRU values (Spearman’s rho1⁄4 0.539, p50.001, Figure 1). We calculated the mean difference between two repeated measures and 95% limits of agreement as the mean difference (2 SD) using the Bland-Altman method [10]. It is expected that the 95% limits include 95% of differences between the two repeated measures. The agreement between the two sets of measurements was not so high, with a mean difference of PRU of 21.3 63.9 (Figure 2). These results indicate that there is a considerable intra-individual variation of the VerifyNow P2Y12 assay in patients receiving clopidogrel after PCI, and that low response to clopidogrel seems to improve over time in some patients. Low platelet inhibition after clopidogrel exposure is related to an increased

The association between serum adiponectin and carotid intima media thickness in community based cohort in Korea: The ARIRANG study

Growing body of evidence suggests an association between circulating adiponectin and the development of atherosclerosis. However most of these studies have been performed with healthy subjects with relatively small sample size or patients with preexisting cardiovascular diseases. The results obtained are inconstant for an independent association between adiponectin and subclinical atherosclerosis. We aimed to evaluate the association between circulating adiponectin and carotid intima media thickness (CIMT) in a large sample of individuals from the community. We performed a non-diabetic community based cohort study conducted on a healthy Korean adults (age>40 years) population. The serum adiponectin concentrations were measured by a radioimmunoassay. The mean adiponectin level was significantly lower in subjects with high CIMT defined by >0.9 mm than those with low CIMT (9.18 vs. 10.44 g/mL, P=0.03). The adiponectin level was correlated negatively with waist circumference (r=−0.27), body mass index (r=−0.21), systolic blood pressure (r=−0.11), diastolic blood pressure (r=−0.10), triglyceride (r=−0.30), LDL-cholesterol (r=−0.02), glucose (r=−0.16), insulin (r=−0.17), homeostasis assessment-insulin resistance (r=−0.23) and C-reactive protein (r=−0.11), and correlated positively with HDL cholesterol (r=0.30) (all P<0.05). Adiponectin was significantly associated with CIMT independently of age, sex, and all metabolic risk factors (R2=0.14, P=0.04). In conclusion, serum adiponectin levels are independently associated with CIMT as a surrogate of subclinical atherosclerosis in a non-diabetic community based cohort.

Abdominal obesity and structure and function of the heart in healthy male Koreans: The ARIRANG study.

AbstractAlthough central obesity is a more powerful predictor of cardiovascular disease (CVD) than general obesity, there is limited information on structural and functional changes of the heart in central obesity. Therefore, we evaluated the association between abdominal obesity and geometric and functional changes of the heart in healthy males. A total of 1460 healthy males aged 40 to 70 years without known CVD from the Korean Genome and Epidemiology Study on Atherosclerosis Risk of Rural Areas in the Korean General Population were included. All individuals underwent conventional 2-dimensional echocardiography and tissue Doppler imaging to measure left atrial (LA) and left ventricle (LV) geometry and function. Increasing tertiles of waist circumference (WC) were associated with stepwise increases in LA volume, LV end-diastolic dimension, LV mass to height2, deceleration time of E wave, and lower E/A ratio (all P trends <0.001). In multivariable logistic regression models, the odds ratios for LA enlargement, LV hypertrophy, LV enlargement, and diastolic dysfunction comparing the upper tertile of WC (>89 cm) to the lowest tertile (<82 cm) were 2.81 (95% confidence interval [CI] 2.24–3.54), 3.65 (95% CI 2.54–5.26), 4.23 (95% CI 2.61–6.87), and 1.75 (95% CI 1.37–2.22), respectively. LV ejection fraction and relative wall thickness were not increased with increasing WC. The association between WC and LA enlargement, LV enlargement, and diastolic dysfunction persisted after stratification by body mass index tertiles. Central obesity may be a stronger predictor than general obesity of geometric and functional changes in the LV and LA.

Successful recanalization of chronic total occlusion of the superior mesenteric artery by transradial approach

It is a challenge to confirm chronic mesenteric ischemia (CMI) as a cause of gastrointestinal (GI) symptoms such as postprandial epigastric bloating, anorexia, and debilitating weight loss. Endovascular intervention for CMI has been gaining popularity because of the high morbidity associated with surgical revascularization. However, in EVI for superior mesenteric artery (SMA) occlusion, the transfemoral approach is limited by difficulty in coaxial alignment of the guiding catheter, which leads to insufficient back-up support. Herein, we report on a 58-year-old male patient with chronic total occlusion of the SMA, which was successfully revascularized by endovascular intervention via the left radial artery. Transradial endovascular therapy may be another treatment option for the treatment of CMI.