Tae Soo Kang

A New Strategy for Discontinuation of Dual Antiplatelet Therapy The RESET Trial (REal Safety and Efficacy of 3-month dual antiplatelet Therapy following Endeavor zotarolimus-eluting stent implantation)

OBJECTIVES The goal of this study was to evaluate shorter duration (3 months) dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation. BACKGROUND There have been few published reports of prospective randomized clinical studies comparing the safety and efficacy of shorter duration DAPT after DES implantation. METHODS We randomly assigned 2,117 patients with coronary artery stenosis into 2 groups according to DAPT duration and stent type: 3-month DAPT following Endeavor zotarolimus-eluting stent (E-ZES) implantation (E-ZES+3-month DAPT, n=1,059) versus 12-month DAPT following the other DES implantation (standard therapy, n=1,058). We hypothesized that the E-ZES+3-month DAPT would be noninferior to the standard therapy for the primary composite endpoint (cardiovascular death, myocardial infarction, stent thrombosis, target\vessel revascularization, or bleeding) at 1 year. RESULTS The primary endpoint occurred in 40 (4.7%) patients assigned to E-ZES+3-month DAPT compared with 41 (4.7%) patients assigned to the standard therapy (difference: 0.0%; 95% confidence interval [CI]: -2.5 to 2.5; p=0.84; p<0.001 for noninferiority). The composite rates of any death, myocardial infarction, or stent thrombosis were 0.8% and 1.3%, respectively (difference: -0.5%; 95% CI: -1.5 to 0.5; p=0.48). The rates of stent thrombosis were 0.2% and 0.3%, respectively (difference: -0.1%; 95% CI: -0.5 to 0.3; p=0.65) without its further occurrence after cessation of clopidogrel in the E-ZES+3-month DAPT group. The rates of target vessel revascularization were 3.9% and 3.7%, respectively (difference: 0.2%; 95% CI: -2.3 to 2.6; p=0.70). CONCLUSIONS E-ZES+3-month DAPT was noninferior to the standard therapy with respect to the occurrence of the primary endpoint. (REal Safety and Efficacy of a 3-month dual antiplatelet Therapy following E-ZES implantation [RESET]; NCT01145079).

Randomized comparison of clinical outcomes between intravascular ultrasound and angiography-guided drug-eluting stent implantation for long coronary artery stenoses

OBJECTIVES This study sought to assess the impact of intravascular ultrasound (IVUS) guidance on clinical outcomes following drug-eluting stent implantation when treating long lesions. BACKGROUND The role of IVUS guidance when treating long lesions has been tested during bare-metal stent, but not during drug-eluting stent, implantation. METHODS A total of 543 patients treated with stents ≥ 28 mm in length were randomly assigned to IVUS guidance (n = 269) versus angiography guidance (n = 274). The primary endpoint was a composite of major adverse cardiac events (MACE), including cardiovascular death, myocardial infarction, target vessel revascularization, or stent thrombosis at 1 year following intervention. RESULTS In the intention-to-treat analysis, total stent length was 32.4 mm in the IVUS-guided arm versus 32.3 mm in angiography-guided arm (p = 0.84). Adjunct post-dilation was more frequently performed in the IVUS-guided arm (54.6% vs. 44.5%, p = 0.03); post-intervention minimal lumen diameters were similar (2.55 vs. 2.55 mm, respectively, p = 0.50); and MACE occurred in 12 (4.5%) patients in IVUS-guided arm and in 20 (7.3%) patients in the angiography-guided arm (p = 0.16). However, among the 269 patients assigned to IVUS guidance, IVUS was not used in 13 patients (4.8%); conversely, in 274 patients assigned to angiography alone, 41 patients (15.0%) were treated with IVUS guidance. Therefore, in a per-protocol analysis according to actual IVUS usage, minimum lumen diameter was larger (2.58 vs. 2.51 mm, p = 0.04), and MACE rates were lower: 4.0% in the IVUS-guided arm versus 8.1% in the angiography-guided arm (p = 0.048). CONCLUSIONS A strategy of routine IVUS for drug-eluting stent implantation in long lesions did not improve the 1-year MACE rates. The IVUS use per operator decision was associated with improved results. (A New Strategy Regarding Discontinuation of Dual Antiplatelet; NCT01145079).

Significance of Small Dense Low-Density Lipoprotein as a Risk Factor for Coronary Artery Disease and Acute Coronary Syndrome

Small dense LDL (sd-LDL) has recently emerged as an important coronary artery disease (CAD) risk factor. This study was performed to investigate how LDL particle size is related to CAD and acute coronary syndrome (ACS). Blood samples were collected from 504 patients that underwent coronary angiography to evaluate chest pain. The LDL particle size of these samples was measured. The mean LDL particle size was smaller in patients with angiographically proven CAD than in the controls (26.41 ± 0.95 vs 26.73 ± 0.64 nm, p < 0.001), and was negatively correlated with the Framingham risk score (r = -0.121, p = 0.007). Patients with more extensive CAD had smaller LDL particles. LDL particle size was also smaller in patients with acute coronary syndrome as compared to non-ACS patients (26.09 ± 1.42 vs 26.54 ± 0.63 nm, p = 0.011). These results suggest that sd-LDL is independently associated with the incidence and extent of CAD, and can be a risk factor for the development of ACS in the Korean population.

Insulin resistance is associated with arterial stiffness in nondiabetic hypertensives independent of metabolic status.

We sought to determine whether insulin resistance (IR) is related to arterial stiffness in nondiabetic hypertensive patients, independent of metabolic status and gender. IR has been associated with increased arterial stiffness in patients with diabetes. In nondiabetic hypertensive patients, the correlation between IR and arterial stiffness has yet to be investigated. We enrolled 284 nondiabetic patients who were being treated for hypertension. At the time of enrollment, the patients underwent a baseline laboratory assessment including homeostatic model assessment (HOMA) IR index and pulse wave velocity (PWV). The HOMA IR index is used as a marker of IR, and brachial to ankle PWV (baPWV) was used as a marker of arterial stiffness. Of the 284 study subjects, 121 were classified as having metabolic syndrome. The patients with metabolic syndrome were older than the non-metabolic syndrome patients (55.4±10.7 vs. 52.1±11.6 years, p=0.013), but there was no gender difference between the two groups. The average baPWV was significantly higher in the patients with metabolic syndrome (1,506±235 vs. 1,435±211 cm/s, p=0.009). The HOMA index was independently associated with an increase in arterial stiffness (r=0.548, p<0.001) after controlling for age, systolic blood pressure (SBP), heart rate, medication and gender. The independent association of HOMA with arterial stiffness was demonstrated in subgroup analysis, regardless of the metabolic status and gender. In conclusion, increased IR was associated with arterial stiffness, independent of age, baseline SBP, gender and heart rate. This independent association of IR was demonstrated regardless of gender and metabolic status.

Pathobiological role of advanced glycation endproducts via mitogen-activated protein kinase dependent pathway in the diabetic vasculopathy

Advanced glycation endproducts (AGEs) have been reported to play a role in neointimal formation and increase the rate of in-stent restenosis (ISR) in the diabetic coronary artery disease patients treated with stents, but the potential pathogenic mechanisms of AGEs in vascular smooth muscle cell proliferation remain unclear. We sought to determine the AGEs related pathobiological mechanism of diabetic vasculopathy. Rat aortic smooth muscle cell (RAoSMC) culture was done with different concentrations of AGEs and proliferation was assessed. Immunohistochemistry for receptor of AGEs (RAGE) was performed with human carotid atheroma. Western blotting was performed to assess the activation of MAP kinase system in the cultured RAoSMC. AGEs increased RAoSMC proliferation and were associated with increased phosphorylation of ERK and p38 kinase by time and dose dependent manner. The MAP kinase activity was decreased by RNA interference for RAGE. AGEs stimulation increased reactive oxygen species (ROS) generation in cultured RAoSMC. From this study it is concluded that AGEs played a key role in RAoSMC proliferation via MAP kinase dependent pathways. Activation of vascular smooth muscle cell (VSMC) proliferation by MAP kinase system and increased formation of ROS may be the possible mechanisms of AGEs induced diabetic vasculopathy.

Efficacy of Subintimal Angioplasty/Stent Implantation for Long, Multisegmental Lower Limb Occlusive Lesions in Patients Unsuitable for Surgery

Purpose: To investigate the feasibility and clinical outcomes of subintimal angioplasty combined with stent implantation in patients with long, multisegmental occlusive lesions unsuitable for surgical treatment. Methods: Between 2003 and 2005, 30 patients (23 men; mean age 68 years, range 49–82) with severe claudication (Rutherford category 3, n=12) or critical limb ischemia (CLI; Rutherford category 4 or 5, n=18) underwent subintimal angioplasty with primary stenting for long (mean 28±11 cm) total occlusion in the lower limb arteries. Bypass surgery was considered unsuitable owing to inappropriate anatomy or poor distal runoff in 14 (47%) patients, severe coronary artery disease 14 (47%), or poor general condition in 2 (6%). Results: Technical success was achieved in 27 (90%) of 30 cases. The 3 technical failures were due to inability to advance the wire, to re-enter the distal lumen, and vessel rupture, respectively. Three (10%) complications occurred (1 perforation, 2 hematomas) but did not require surgery. After a mean follow-up of 13±7 months (range 3–28), 10 (37%) cases of restenosis were found in 27 patients. At 12 months, the primary patency rate was 52%, and the limb salvage rate was 83%. Conclusion: Combined use of subintimal angioplasty and stent implantation was performed safely, with a relatively high success rate and acceptable intermediate-term clinical outcomes in patients with multisegmental, long occlusions of the lower limb arteries. Therefore, this strategy can be considered an option for symptomatic relief and limb salvage in patients unsuitable for bypass surgery due to various reasons.

Serum Levels of Advanced Glycation End Products Are Associated with In-Stent Restenosis in Diabetic Patients

The formation of advanced glycation end products (AGEs), in various tissues has been known to enhance immunoinflammatory reactions and local oxidant stresses in long standing diabetes. Recently, AGEs have been reported to play a role in neointimal formation in animal models of arterial injury. We attempted to determine whether the serum levels of AGEs are associated with coronary restenosis in diabetic patients. Blood samples were collected from diabetic patients with coronary artery disease undergoing stent implantation and the serum levels of AGEs were analyzed by the fluorescent intensity method. The development of in-stent restenosis (ISR) was evaluated by a 6-month follow-up coronary angiography. A total of 263 target lesions were evaluated, in 203 patients. The ISR rate in the high-AGE (>170 U/ml) group (40.1%) was significantly higher than in the low-AGE group (≤170 U/ml) (19.6%) (p<0.001). Furthermore, multivariate analysis revealed that a high level of serum AGEs is an independent risk factor for the development of ISR (odds ratio, 2.659; 95% CI, 1.431-4.940; p=0.002). The serum levels of AGEs constitute an excellent predictive factor for ISR, and should be one of the guidelines for medical therapy and interventional strategy to prevent ISR in diabetic patients.

Additive beneficial effects of valsartan combined with rosuvastatin in the treatment of hypercholesterolemic hypertensive patients.

Background and Objectives We compared the efficacy and safety of valsartan and rosuvastatin combination therapy with each treatment alone in hypercholesterolemic hypertensive patients. Subjects and Methods Patients who met inclusion criteria were randomized to receive 1 of the following 2-month drug regimens: valsartan 160 mg plus rosuvastatin 20 mg, valsartan 160 mg plus placebo, or rosuvastatin 20 mg plus placebo. The primary efficacy variables were change in sitting diastolic blood pressure (sitDBP) and sitting systolic blood pressure (sitSBP), and percentage change in low-density lipoprotein-cholesterol (LDL-C) in the combination, valsartan, and rosuvastatin groups. Adverse events (AEs) during the study were analyzed. Results A total of 354 patients were screened and 123 of them were finally randomized. Changes of sitDBP by least squares mean (LSM) were -11.1, -7.2, and -3.6 mm Hg, respectively, and was greater in the combination, as compared to both valsartan (p=0.02) and rosuvastatin (p<0.001). Changes of sitSBP by LSM were -13.2, -10.8, and -4.9 mm Hg, and was greater in the combination, as compared to rosuvastatin (p=0.006) and not valsartan (p=0.42). Percentage changes of LDL-C by LSM were -52, -4, and -47% in each group, and was greater in the combination, as compared to valsartan (p<0.001), similar to rosuvastatin (p=0.16). Most AEs were mild and resolved by the end of the study. Conclusion Combination treatment with valsartan and rosuvastatin exhibited an additive blood pressure-lowering effect with acceptable tolerability, as compared to valsartan monotherapy. Its lipid lowering effect was similar to rosuvatatin monotherapy.

Apoptosis in dilated cardiomyopathy.

Objective Cardiomyopathy, a popular diagnosis that always obscures more than it reveals, nevertheless has several characteristic histological features. These prominently include widespread focal myocardial fibrosis and associated hypertrophy of surviving cardiac myocyte, in fact, focal noninflammatory degeneration (not necrosis) has been demonstrated as a feature of many forms of cardiac hypertrophy. We hypothesized that this loss of myocardial cells in dilated cardiomyopathy (DCMP) may result from cell death by apoptosis. Methods Endomyocardial biopsy specimens from the right ventricles of six patients who suffered from DCMP were studied, and myocardial specimens from two persons who died in motor vehicle accidents were used as negative controls. For identification of apoptosis, immunohistochemistry with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling was performed, in addition, apoptosis was confirmed morphologically by confocal laser scanning microscopy with propidium iodide. Results Apoptosis, that was represented by an apoptotic index ranging from 19.8 to 25.4%, could be extensively seen in myocytes and a/so rarely in non-myocytes of interstitium and vascular endothelium. Morphologically, there were a lot of nuclei with dumps of condensed chromatin, suggestive of apoptosis. Conclusion The present study demonstrated that myocyte loss in DCMP might be mainly due to the apoptosis of myocytes and interstitial cells, rather than inflammation or cell necrosis.

Total occlusion of left main coronary artery by dilated main pulmonary artery in a patient with severe pulmonary hypertension.

A 34-year-old woman was admitted to the hospital because of recently aggravated right heart failure without angina for 5 months. When she was 25 years old, patch repair with Polytetrafluoroethylene (PTFE) was performed for the secondum type of atrial septal defect (ASD) with moderate pulmonary hypertension. The chest PA, echocardiography and cardiac catheterization at current admission revealed Eisenmenger syndrome without intracardiac shunt. Chest CT scan with contrast revealed markedly dilated pulmonary trunk, both pulmonary arteries and concave disfigurement of the left side of the ascending aorta suggesting extrinsic compression, as well as total occlusion of the ostium of the left main coronary artery that was retrogradly filled with collateral circulation from the right coronary artery. The coronary angiography showed normal right coronary artery and the collaterals that come out from the conus branch to the mid-left anterior descending artery (LAD) and that from distal right coronary artery to the left circumflex artery (LCX) and to the distal LAD, respectively. On aortography, the left main coronary artery was not visualized with no stump, suggestive of total occlusion of the ostium of the left main coronary artery. From our experience, it is possible to say that the occlusion of the ostium of the left main coronary can be induced by the dilated pulmonary artery trunk due to ASD with pulmonary hypertension and that, if the ASD closure was too late, the narrowing or obstruction of the left coronary artery could not be resolved even after operation owing to irreversible pulmonary hypertension.