The Relationship between Heart Rate Variability and Aortic Knob Width / 가정의학회지

BACKGROUND: The aortic knob width (AKW) and the heart rate variability (HRV) were suggested to be related to development of cardiovascular diseases. However, the relationship between them has not been investigated; thus, this study aimed to determine this relationship. METHODS: This study included 587 Koreans aged 18–79 years. Their physical measurements, medical and social histories, blood test findings, and chest radiographs were obtained. The HRV parameters included the standard deviation of the N-N interval (SDNN), root mean square of successive differences (RMSSD), approximate entropy (ApEn), total power (TP), very low frequency (VLF), low frequency (LF), high frequency (HF), and LF/HF ratio, which were measured for 5 minutes. The AKW was measured on chest radiographs by a single reviewer. RESULTS: The AKW was significantly correlated with the HRV parameters, except for the LF/HF ratio. However, RMSSD and ApEn were not significantly related to the AKW in women. After dividing the participants into quartile groups, the AKW was significantly related to the SDNN, RMSSD, TP, VLF, LF, and HF. The HRV parameter values decreased in the higher AKW quartile groups, the HRV parameter values decreased. After adjusting for sex, drinking status, exercise habits, smoking status, waist circumference, and triglyceride, low-density lipoprotein cholesterol, fasting blood sugar, and glycated hemoglobin levels, the AKW showed significant negative associations with the HRV parameters, except for the LF/HF ratio. CONCLUSION: The AKW is significantly associated with the HRV parameters of SDNN, RMSSD, ApEn, TP, VLF, LF, and HF.

Factors associated hospital admission in patients with low acuity visiting emergency department

OBJECTIVE: Patients with low acuity who need hospitalization may be at risk if they do not receive proper treatment in overcrowded emergency rooms. This study was conducted to investigate factors affecting the hospitalization of patients with low acuity of Korean Triage and Acuity Scale (KTAS). METHODS: This study was a retrospective chart review analysis of patients aged 15 years or older who had triaged as KTAS 4 and 5 grades when visiting a local emergency medical center from January 1, 2016 to December 31, 2017. Multivariate logistic analysis was performed to analyze the effects of age, sex, reasons for visiting, visiting route, ambulance utilization, KTAS grade and major category on patient admission. RESULTS: A total of 10,540 patients were enrolled and the odds ratio (OR) increased with age from those aged over 34 years (P < 0.001). Patients that triaged as KTAS grade 5 (adjusted OR, 1.57; 95% confidence interval [CI], 1.36–1.82), had a condition caused by disease (adjusted OR, 2.31; 95% CI, 2.00–2.68), and visited by using an ambulance (public: adjusted OR, 1.05; 95% CI, 0.91–1.22; private: adjusted OR, 4.60; 95% CI, 3.85–5.49) were more likely to be hospitalized. Individuals in the “general” major category were more likely to be hospitalized than those falling into other major categories (P < 0.001). CONCLUSION: The factors influencing the hospitalization of patients with low acuity were age, reasons for visiting, visiting route, ambulance utilization, KTAS grade and major category on patient admission.

Diabetes and Subclinical Coronary Atherosclerosis

It is well known that diabetic patients have a high risk of cardiovascular events, and although there has been a tremendous effort to reduce these cardiovascular risks, the incidence of cardiovascular morbidity and mortality in diabetic patients remains high. Therefore, the early detection of coronary artery disease (CAD) is necessary in those diabetic patients who are at risk of cardiovascular events. Significant medical and radiological advancements, including coronary computed tomography angiography (CCTA), mean that it is now possible to investigate the characteristics of plaques, instead of solely evaluating the calcium level of the coronary artery. Recently, several studies reported that the prevalence of subclinical coronary atherosclerosis (SCA) is higher than expected, and this could impact on CAD progression in asymptomatic diabetic patients. In addition, several reports suggest the potential benefit of using CCTA for screening for SCA in asymptomatic diabetic patients, which might dramatically decrease the incidence of cardiovascular events. For these reasons, the medical interest in SCA in diabetic patients is increasing. In this article, we sought to review the results of studies on CAD in asymptomatic diabetic patients and discuss the clinical significance and possibility of using CCTA to screen for SCA.

Early experience and favorable clinical outcomes of everolimus-eluting bioresorbable scaffolds for coronary artery disease in Korea

BACKGROUND/AIMS: Compared with metallic drug-eluting stents (DES), bioresorbable vascular scaffolds (BVS) may further improve long-term outcomes of percutaneous coronary intervention (PCI) in patients with coronary artery disease. We report our early experience with BVS in Korea. METHODS: We evaluated 105 consecutive patients with BVS implanted at Asan Medical Center, Korea between October 21, 2015 and June 3, 2016. Angiographic results, and in-hospital and 6-month clinical outcomes were assessed. RESULTS: A total of 134 BVS were implanted to treat 115 lesions. The mean age was 62 ± 10.5 years; 85 patients (81%) were males, 26 patients (25%) were presented with acute coronary syndrome. Among 115 lesions treated with BVS, 76 (66.1%) were B2/C type, 27 (23.5%) were bifurcation lesions, and four (3.5%) were chronic total occlusion. Pre-dilation and post-dilation using high-pressure non-compliant balloon was performed in 104 lesions (90.4%) and 113 lesions (98.2%), respectively. During the procedure, intravascular imaging was used for all patients (100%; intravascular ultrasound 89 and optical coherence tomography 40 patients). Device success rate was 100%. In-segment and in-scaffold acute again were 1.1 ± 0.6 and 1.3 ± 0.5 mm, respectively. Periprocedural myocardial infraction occurred in four patients (3.8%). No deaths, stent thrombosis, or urgent revascularizations occurred either during hospitalization or the follow-up period. CONCLUSIONS: In this single-center experience, implantation of BVS with intravascular imaging support was feasible and early clinical outcomes were excellent. Evaluation of long-term efficacy and safety of BVS and its feasibility in clinical use for a broader range of lesions is warranted.

Factors affecting the urologist’s decision to administer ureteral stone therapy: a retrospective cohort study

OBJECTIVE: We aimed to evaluate the factors influencing treatment option selection among urologists for patients with ureteral stones, according to the stone diameter and location. METHODS: We retrospectively reviewed the records of 360 consecutive patients who, between January 2009 and June 2014, presented to the emergency department with renal colic and were eventually diagnosed with urinary stones via computed tomography. The maximal horizontal and longitudinal diameter and location of the stones were investigated. We compared parameters between patients who received urological intervention (group 1) and those who received medical treatment (group 2). RESULTS: Among the 360 patients, 179 (49.7%) had stones in the upper ureter and 181 (50.3%) had stones in the lower ureter. Urologic intervention was frequently performed in cases of upper ureteral stones (P<0.001). In groups 1 and 2, the stone horizontal diameters were 5.5 mm (4.8 to 6.8 mm) and 4.0 mm (3.0 to 4.6 mm), stone longitudinal diameters were 7.5 mm (6.0 to 9.5 mm) and 4.4 mm (3.0 to 5.5 mm), and ureter diameters were 6.4 mm (5.0 to 8.0 mm) and 4.7 mm (4.0 to 5.3 mm), respectively (P<0.001). The cut-off values for the horizontal and longitudinal stone diameters in the upper ureter were 4.45 and 6.25 mm, respectively (sensitivity 81.3%, specificity 91.4%); those of the lower ureter were 4.75 and 5.25 mm, respectively (sensitivity 79.4%, specificity 79.4%). CONCLUSION: The probability of a urologic intervention was higher for patients with upper ureteral stones and those with stone diameters exceeding 5 mm horizontally and 6 mm longitudinally.

Impact of Follow-Up Ischemia on Myocardial Perfusion Single-Photon Emission Computed Tomography in Patients with Coronary Artery Disease

PURPOSE: Few studies have reported on predicting prognosis using myocardial perfusion single-photon emission computed tomography (SPECT) during coronary artery disease (CAD) treatment. Therefore, we aimed to assess the clinical implications of myocardial perfusion SPECT during follow-up for CAD treatment. MATERIALS AND METHODS: We enrolled 1153 patients who had abnormal results at index SPECT and underwent follow-up SPECT at intervals ≥6 months. Major adverse cardiac events (MACE) were compared in overall and 346 patient pairs after propensity-score (PS) matching. RESULTS: Abnormal SPECT was associated with a significantly higher risk of MACE in comparison with normal SPECT over the median of 6.3 years (32.3% vs. 19.8%; unadjusted p<0.001). After PS matching, abnormal SPECT posed a higher risk of MACE [32.1% vs. 19.1%; adjusted hazard ratio (HR)=1.73; 95% confidence interval (CI)=1.27–2.34; p<0.001] than normal SPECT. After PS matching, the risk of MACE was still higher in patients with abnormal follow-up SPECT in the revascularization group (30.2% vs. 17.9%; adjusted HR=1.73; 95% CI=1.15–2.59; p=0.008). Low ejection fraction [odds ratio (OR)=5.33; 95% CI=3.39–8.37; p<0.001] and medical treatment (OR=2.68; 95% CI=1.93–3.72; p<0.001) were independent clinical predictors of having an abnormal result on follow-up SPECT. CONCLUSION: Abnormal follow-up SPECT appears to be associated with a high risk of MACE during CAD treatment. Follow-up SPECT may play a potential role in identifying patients at high cardiovascular risk.

Coronary Artery Bypass Grafting vs. Drug-Eluting Stent Implantation for Multivessel Disease in Patients with Chronic Kidney Disease

BACKGROUND AND OBJECTIVES: There is currently a limited amount of data that demonstrate the optimal revascularization strategy for chronic kidney disease (CKD) patients with multivessel coronary artery disease (CAD). We compared the long-term outcomes of percutaneous coronary intervention (PCI) with drug-eluting stents (DES) versus coronary artery bypass graft surgery (CABG) for multivessel CAD in patients with CKD. SUBJECTS AND METHODS: We analyzed 2108 CKD patients (estimated glomerular filtration rate <60 mL/min/1.73 m²) with multivessel CAD that were treated with PCI with DES (n=1165) or CABG (n=943). The primary outcome was a composite of all causes of mortality, myocardial infarction, or stroke. The mean age was 66.9±9.1 years. RESULTS: Median follow-up duration was 41.4 (interquartile range 12.1-75.5) months. The primary outcome occurred in 307 (26.4%) patients in the PCI group compared with 304 (32.2%) patients in the CABG group (adjusted hazard ratio [HR], 0.941; 95% confidence interval [CI], 0.79–1.12; p=0.493). The two groups exhibited similar rates of all-cause mortality (adjusted HR, 0.91; 95% CI, 0.77–1.09; p=0.295), myocardial infarction (adjusted HR, 1.86; 95% CI, 0.85–4.07; p=0.120) and stroke (3.2% vs. 4.8%; HR, 0.93; 95% CI, 0.57–1.61; p=0.758). However, PCI was associated with significantly increased rates of repeat revascularization (adjusted HR, 4.72; 95% CI, 3.20–6.96; p<0.001). CONCLUSION: Among patients with CKD and multivessel CAD, PCI with DES when compared with CABG resulted in similar rates of composite outcome of mortality from any cause, MI, or stroke; however, a higher risk of repeat revascularization was observed.

Monitoring the Antiplatelet Effect of Cilostazol with Light Transmission Aggregometer: Two Cases of Possible Cilostazol Resistance

BACKGROUND: Coronary artery disease is an important cause of death in adults and stent insertion is one of the treatment modalities. The most severe adverse effect of a stent insertion is the formation of a thrombus; therefore, antiplatelet agents are used. The addition of cilostazol to low-dose aspirin and clopidogrel results in a better antiplatelet effect. However, laboratory tests to monitor the effect of cilostazol are insufficient. METHODS: We tested the inhibitory effect of cilostazol using maximal platelet aggregation in 20 healthy volunteers. Conditions for incubation and concentrations of cilostazol and prostaglandin E1 (PGE1) were established and aggregation was induced by 5'-adenosine diphosphate (ADP) and measured with light transmission aggregometry (LTA). Blood samples were incubated with 1 µM and 2 µM cilostazol for 10 minutes at room temperature, and 80 nM PGE1 was added and incubated for an additional 10 minutes. Aggregation was induced by ADP and reactivity was evaluated. RESULTS: The average maximum aggregation (MA) was 58.1% at 1 µM cilostazol and 22.0% when PGE1 was added. The average MA was 42.8% when cilostazol concentration was increased to 2 µM and 21.2% when PGE1 was added. Average inhibition of aggregation at 1 µM cilostazol was not statistically significant (P=0.085), but was significant (P=0.004) at 2 µM cilostazol. Aggregation was not inhibited even with 2 µM cilostazol and PGE1 in 2 volunteers, which suggests possible resistance to cilostazol. CONCLUSIONS: We designed a method to monitor the effect of cilostazol using in vitro incubation with PGE1.

Role of Coronary Artery Calcium Scoring in Detection of Coronary Artery Disease according to Framingham Risk Score in Populations with Low to Intermediate Risks

Current guidelines recommend that coronary artery calcium (CAC) screening should only be used for intermediate risk groups (Framingham risk score [FRS] of 10%-20%). The CAC distributions and coronary artery disease (CAD) prevalence in various FRS strata were determined. The benefit to lower risk populations of CAC score-based screening was also assessed. In total, 1,854 participants (aged 40-79 years) without history of CAD, stroke, or diabetes were enrolled. CAC scores of > 0, ≥ 100, and ≥ 300 were present in 33.8%, 8.2%, and 2.9% of the participants, respectively. The CAC scores rose significantly as the FRS grew more severe (P 20% strata were 3.4%, 6.7%, 9.0%, and 11.6% (P 20%; P < 0.05). In conclusion, the yield of screening for significant CAC and occult CAD is low in the very low risk population but it rises in low and intermediate risk populations.

Two Cases of Immediate Stent Fracture after Zotarolimus-Eluting Stent Implantation

Drug-eluting stent (DES) implantation is currently the standard treatment for various types of coronary artery disease. However, previous reports indicate that stent fractures, which usually occur after a period of time from the initial DES implantation, have increased during the DES era; stent fractures can contribute to unfavorable events such as in-stent restenosis and stent thrombosis. In our present report, we describe two cases of zotarolimus-eluting stent fracture: one that was detected six hours after implementation, and the other case that was detected immediately after deployment. Both anatomical and technical risk factors contributed to these unusual cases of immediate stent fracture.

Acute and Long-Term Angiographic Outcomes of Side Branch Stenosis after Randomized Treatment of Zotarolimus-, Sirolimus-, and Paclitaxel-Eluting Stent for Coronary Artery Stenosis

This was designed to assess the outcomes of side branch (SB) stenosis after implantation of three drug-eluting stents (DES). From 2,645 patients in the ZEST (Comparison of the Efficacy and Safety of Zotarolimus-Eluting Stent with Sirolimus-Eluting and PacliTaxel-Eluting Stent for Coronary Lesions) Trial, 788 patients had 923 bifurcation lesions with SB > or = 1.5 mm were included. SB was treated in 150 lesions, including 35 (3.8%) receiving SB stenting. Of untreated SB with baseline stenosis < 50%, the incidences of periprocedural SB compromise was similar in the zotarolimus (15.8%), sirolimus (17.2%), and paclitaxel (16.6%) stent groups (P = 0.92). At follow-up angiography, delayed SB compromise occurred in 13.9%, 3.2%, and 9.4% (P = 0.010) of these groups. When classified into four groups (< 50%, 50%-70%, 70%-99%, and 100%), 9.0% of untreated SB were worsened, whereas improvement and stationary were observed in 9.6% and 81.4%. In a multivariable logistic regression model, main branch (MB) stenosis at follow-up (%) was the only independent predictor of SB stenosis worsening (odds ratio, 1.03; 95% confidence interval, 1.01-1.04; P < 0.001). After MB stenting in bifurcation lesions, a minority of SB appears to worsen. DES with strong anti-restenotic efficacy may help maintain SB patency.

Transcatheter Aortic Valve Implantation: Early Experience in Korea

BACKGROUND AND OBJECTIVES: Transcatheter aortic valve implantation (TAVI) was recently introduced in Korea. The present report describes the experience of early TAVI cases. SUBJECTS AND METHODS: Between March, 2010 and October, 2011, 48 patients with severe symptomatic aortic stenosis (AS) were screened at the Asan Medical Center to determine their suitability for surgical intervention. Of these, 23 were considered unsuitable and underwent TAVI. Procedural success rates, procedure-related complications, and clinical outcomes were evaluated in the TAVI patients. RESULTS: Transfemoral (n=20) or transapical (n=3) TAVI was performed. The mean age of patients was 75.9+/-5.4 years and 57% were females. The mean logistic European System for Cardiac Operative Risk Evaluation was 25.6+/-5.1%. Implantation was successful in 22 patients (19 transfemoral, three transapical). After successful implantation, the mean aortic valve area increased from 0.68+/-0.14 cm2 to 1.45+/-0.33 cm2. There were no procedure-related complications or mortality. The patients showed no paravalvular aortic regurgitation with > or = moderate degree and remained stable without progression during follow-up. During follow-up (interquartile range, 1.1-12.9), all patients were alive without any occurrence of valve failure. CONCLUSION: TAVI procedure is feasible in patients with inoperative symptomatic AS leading to hemodynamic and clinical improvement. With accumulation of experience, proper patient selection and development of device technologies, TAVI should decrease adverse events and expand the indications in the near future.

A Case of Pantoea species Cholangitis with Bacteremia

Pantoea infections are rare in humans and an unusual cause for sepsis in immunocompetent patient. It is a gram-nagative bacillus of the family Enterobacteriaceae. Infections are usually associated with plant thorn injury or outbreak traced to comtaminated parenteral nutrition. We experienced a case of pantoea species cholecystitis and cholangitis with bacteremia. The patient was administrated intravenous antibiotics, and then patient was improved.

Procedure-Induced Acute Common Carotid Artery Perforation Presenting With Airway Obstruction and Successful Treatment by Endovascular Stent Graft

A 63-year-old female was admitted to our hospital for catheter ablation during atrial fibrillation. After catheter ablation, the patient was transferred to the cardiac care unit and mechanically ventilated due to dyspnea and hypotension. Imaging showed active bleeding from the right common carotid artery (CCA) with extensive hematoma into the mediastinum. She was successfully treated with a stent graft at the CCA. Further bleeding or neurologic sequel did not occur after treatment.

Variable Association between Components of the Metabolic Syndrome and Electrocardiographic Abnormalities in Korean Adults

BACKGROUND/AIMS: Resting electrocardiogram (ECG) abnormalities have been strongly associated with cardiovascular disease mortality. Little is known, however, about the association between individual components of metabolic syndrome and ECG abnormalities, especially in Asian populations. METHODS: We examined clinical and laboratory data from 31,399 subjects (age 20 to 89 years) who underwent medical check-ups. ECG abnormalities were divided into minor and major abnormalities based on Novacode criteria. Ischemic ECG findings were separately identified and analyzed. RESULTS: The overall prevalence rates of ECG abnormalities were significantly higher in subjects with than in those without metabolic syndrome (p < 0.01). Ischemic ECG was strongly associated with metabolic syndrome in all age groups of both sexes, except for younger women. In multiple logistic regression analysis, metabolic syndrome was independently associated with ischemic ECG (odds ratio, 2.30 [2.04 to 2.62]; p < 0.01), after adjusting for sex, age, smoking, and family history of cardiovascular disease. Of the metabolic syndrome components, hyperglycemia in younger subjects and hypertension in elderly subjects were major factors for ischemic ECG changes, whereas hypertriglyceridemia was not an independent risk factor in any age group. The association between ischemic ECG findings and central obesity was weaker in women than in men. CONCLUSIONS: Metabolic syndrome was strongly associated with ECG abnormalities, especially ischemic ECG findings, in Koreans. The association between each component of metabolic syndrome and ECG abnormalities varied according to age and sex.

Comparison of Myocardial Contrast Echocardiography Versus Rest Sestamibi Myocardial Perfusion Imaging in the Early Diagnosis of Acute Coronary Syndrome

BACKGROUND: It remains unclear whether myocardial contrast echocardiography (MCE) is as accurate as myocardial perfusion imaging with technetium-99m sestamibi (MPI) for the diagnosis of acute coronary syndrome (ACS). We sought to directly compare the diagnostic accuracy of MCE with resting MPI in a head-to-head fashion. METHODS: We prospectively enrolled 98 consecutive patients (mean age; 59+/-9 years, 68 males) who presented to the emergency department with chest pain suggestive of acute myocardial ischemia. Early MCE was performed by using continuous infusion of perfluorocarbon-exposed sonicated dextrose albumin (PESDA) during intermittent power Doppler harmonic imaging. Myocardial perfusion defects observed in at least one coronary territory were considered positive. Sestamibi was injected immediately after MCE and MPI was obtained within 6 hours of tracer injection. RESULTS: ACS was confirmed in 67 patients. There were 32 patients with acute myocardial infarction (AMI) and 35 patients with unstable angina requiring urgent revascularization. The sensitivities of MCE and MPI for the diagnosis of ACS were 72% and 61%, respectively, which were significantly higher than those of ST segment change (24%, p<0.001 vs. MCE and vs. MPI) and troponin I (27%, p<0.001 vs. MCE and vs. MPI), with similar specificities of 90% to 100%. On a receiveroperating characteristics curve demonstrating diagnostic accuracy for ACS, the area under the curve of MCE was significantly larger than that of MPI (0.86 vs. 0.77, respectively; p=0.019). CONCLUSION: MCE and MPI overcome the low sensitivity of routine triage tests for detecting ACS, and MCE is more accurate than MPI for the diagnosis of ACS in the emergency department.

Effect of Anastomotic Method on Intimal Hyperplasia in Rabbit Aorta

PURPOSE: The clinical advantages of end-to-end (ETE) anastomosis have not been clear despite its biomechanical advantage over end-to-side (ETS) anastomosis. We compared the histomorphometric features of intimal remodeling after ETE and ETS anastomosis in a rabbit aortic bypass model. METHODS: Thirty-two bypass operations, 16 with ETS and 16 with ETE anastomoses, were performed using aortic allografts of donor rabbits (15 per group) and polytetrafluoroethylene (PTFE) grafts (1 per group). To minimize bias from the immunologic response to aortic allografts or graft size, a long aortic tissue obtained from one donor was divided into 2 pieces and shared between each ETE and ETS bypass. PTFE graft bypasses, which are commonly used in clinical practice, were performed to provide comparison results for an allograft with a different compliance. Vessels were harvested at 1 day (1 per group), 5 days (1 per group), and 4 weeks (14 per group, including the PTFE bypass group) after surgery. Intimal thickening was evaluated with hematoxylin-eosin, van Gieson, immunohistochemical staining and Western blot analysis of TNF-alpha and proliferative cell nuclear antigen (PCNA) expression. RESULTS: Mean intimal thickness and volume (0.721+/-0.047 mm, 5.734+/-0.387 mm3 vs. 0.883+/-0.048 mm, 9.068+/-0.462 mm3) and intima/media volume ratio (0.70+/-0.05 vs 1.08+/-0.06) were significantly smaller in ETE (P<0.05). Western blotting showed a marked increase in TNF-alpha (203.15+/-5.29 vs. 494.49+/-6.11) and PCNA concentrations (152.66+/-7.37 vs. 175.53+/-4.36) in the ETS group. CONCLUSION: ETE anastomosis results showed significantly decreased inflammatory reaction and volume of intimal hyperplasia, and therefore seemed to be associated with better long-term graft patency.

Clinical outcomes according to coronary calcium scores in asymptomatic individuals undergoing coronary CT angiography / 대한내과학회지

BACKGROUND/AIMS: In general, multidetector computed tomography (MDCT) is not recommended as a screening tool for asymptomatic individuals. However, the programs for general health evaluation at several hospitals in Korea include MDCT to detect cardiac disease. The objectives of this study were to evaluate the clinical outcomes of asymptomatic individuals according to the coronary artery calcium score (CACS) obtained from screening MDCT and to assess the eligibility of risk stratification in the NCEP-ATP III guidelines for predicting a significant stenosis on MDCT. METHODS: We reviewed the medical records of 845 asymptomatic subjects (age 53+/-9 years, 67% men) who underwent MDCT as part of a general health evaluation at Asan Medical Center, Seoul, Korea, from January to December 2008. RESULTS: Atherosclerotic plaques were identified in 332 (39.3%) subjects. Sixty (7.1%) individuals had significant stenosis (> or = 50% diameter stenosis). The prevalence of significant stenosis was higher in the group that had more than a 10% risk of coronary heart disease (CHD) at 10 years (p or = 110 was associated with a significantly higher rate of coronary revascularization in asymptomatic patients with significant stenosis on MDCT.

Clinical impact of aspirin resistance measured using the Ultegra Rapid Platelet Function Assay-ASA in patients undergoing percutaneous coronary intervention / 대한내과학회지

BACKGROUND/AIMS: Aspirin resistance is reported to be associated with myocardial infarction, stroke, and myonecrosis after percutaneous coronary intervention. However, aspirin resistance and its clinical implications in patients undergoing drug-eluting stent (DES) implantation have not been evaluated sufficiently. METHODS: The study enrolled 419 consecutive patients who underwent DES implantation. All of the patients took aspirin 100 mg (228 patients, 54.4%) or 200 mg (191 patients, 45.6%). Aspirin resistance was measured using the Ultegra Rapid Platelet Function Assay-ASA (Accumetrics, San Diego, CA, USA). The results were expressed as aspirin reaction units (ARU). Aspirin resistance was defined as ARU > or =550. We followed all patients for 9 months. RESULTS: Aspirin resistance was found in 33 patients (33/419, 7.9%). The aspirin dose (118.18+/-39.2 vs. 147.93+/-50.0 mg, p= 0.011) was lower in the aspirin-resistant (n=33) versus the aspirin-sensitive (n=386) group. There was no significant difference in the occurrence of myocardial necrosis (15.6% vs. 15.5%, p=0.988). On multivariate analysis, low-dose aspirin (odds ratio (OR) 4.714; 95% confidence interval (CI) 1.865-11.914; p=0.001), age (OR 1.048; 95% CI 1.005-0.092, p=0.029), platelet count (OR 1.007; 95% CI 1.001-1.014, p=0.011), and hypercholesterolemia (OR 2.937; 95% CI 1.310-6.583, p=0.009) were independent predictors of aspirin resistance. Over the 9 months, no stent thrombosis or death occurred; one acute myocardial infarction occurred in the aspirin-sensitive group. CONCLUSIONS: Low-dose aspirin, old age, a higher platelet count, and hypercholesterolemia were associated with a high incidence of aspirin resistance in patients who underwent DES implantation. However, no significant differences in clinical outcome were found between the aspirin-resistant and -sensitive groups during a 9-month follow-up.

Frequency of Silent Myocardial Ischemia Detected by Thallium-201 SPECT in Patients with Type 2 Diabetes / 당뇨병

BACKGROUND: Silent myocardial ischemia (SMI) is more common in diabetic patients than among the general population. It is not yet established whether a routine screening test for SMI is necessary, and which screening test would be most useful. The purpose of this study was to estimate the prevalence of SMI detected by Thallium-201 perfusion single photon emission computed tomography (SPECT) in type 2 diabetic patients. METHODS: A total of 173 asymptomatic type 2 diabetic patients were included in the study. Thallium-201 perfusion SPECT was performed to screen for SMI. RESULTS: Among the 173 patients, abnormal perfusion patterns were found in 11 patients. Coronary angiography was carried out for these patients, and significant coronary artery stenosis was found in ten of them (positive predictive value; 90.9%). There was a significant association between SMI and overt albuminuria (OR = 7.33, 95% CI, 1.825-29.437). CONCLUSION: Thallium-201 perfusion SPECT is not sensitive enough to identify SMI, but is accurate in detecting decreased myocardial perfusion. This may be a useful screening tool for detecting SMI in type 2 diabetic patients with impaired renal function.