High Brachial Ankle Pulse Wave Velocity as a Marker for Predicting Coronary Artery Stenosis in Patients with Type 2 Diabetes

BACKGROUND: We evaluated the ability of brachial ankle pulse wave velocity (baPWV) to predict coronary artery stenosis (CAS) in patients with type 2 diabetes, and compared the predictive power of baPWV to that of well-known cardiovascular disease (CVD) risk calculators. METHODS: The study group included 83 consecutive patients over 30 years old with type 2 diabetes who complained of vague chest discomfort. An automatic pulse waveform analyzer was used to measure baPWV. CAS was measured using multi-slice computed tomographic (MSCT) angiography. RESULTS: Age, maximal baPWV, duration of diabetes, current smoking, the UK Prospective Diabetes Study (UKPDS) Risk Engine score, American College of Cardiology/American Heart Association (ACC/AHA) risk estimator score, the Framingham risk calculator score, and coronary artery calcium score were greater in patients with CAS than in those without CAS. An area under the curve (AUC) indicative of a predictive value for CAS (≥20%) was found for several parameters. The AUC of maximal baPWV, the UKPDS Risk Engine, the ACC/AHA ASCVD risk estimator, and the Framingham risk calculator were 0.672 (95% confidence interval [CI], 0.554 to 0.785; P=0.010), 0.777 (95% CI, 0.675 to 0.878; P < 0.001), 0.763 (95% CI, 0.660 to 0.866; P < 0.001), and 0.736 (95% CI, 0.629 to 0.843; P < 0.001), respectively. The optimal cutoff value of baPWV for the detection of CAS was 1,650 cm/sec (sensitivity, 68.9%; specificity, 63.2%). CONCLUSION: Maximal baPWV was closely related with CAS detected by MSCT coronary angiography in patients with type 2 diabetes. baPWV has the potential to be a useful, noninvasive screening tool for the prediction of occult CAS in patients with type 2 diabetes.

Relationships between Cardiac Autonomic Neuropathy and the Brachial-ankle Pulse Wave Velocity in Patients with Type 2 Diabetes

BACKGROUND: Cardiovascular disease is the leading cause of death in patients with type 2 diabetes. Clinically, evaluating cardiovascular autonomic neuropathy (CAN) is important to predict cardiovascular mortality because it is correlated with cardiovascular death. The pulse wave velocity (PWV) correlates well with arterial distensibility and stiffness. It is also a useful approach for evaluating the severity of systemic atherosclerosis in adults. So, we evaluated that the relationship between cardiac autonomic neuropathy and the brachial-ankle pulse wave velocity (baPWV) in patients with type 2 diabetes. METHODS: We retrospectively analyzed 465 patients (209 men and 256 women) with type 2 diabetes. We checked the clinical characteristics and the laboratory tests and we assessed the diabetic complications. Standard tests for CAN were performed by DiCAN (Medicore, Seoul, Korea): 1) heart rate variability during deep breathing (the E/I ratio), 2) a Valsalva maneuver, 3) 30:15 ratio of R-R interval the blood pressure response to standing, and 5) the blood pressure response to handgrip. The CAN score was determined according to the results of the test as following: 0 = normal, 0.5 = borderline, 1 = abnormal. We also measured the baPWV by using a VP 1000 (Colin, Japan) and all the analyses were performed with the SPSS version 14.0. P values < 0.05 were considered significant. RESULTS: The CAN score is associated with the maximal baPWV, age, systolic blood pressure, microalbuminuria, the duration of diabetes, angiotensin II receptor blocker treatment, calcium channel blocker treatment, beta-blocker treatment and nephropathy. After adjusting for age, the baPWV is a independent predictor of the risk for CAN (beta = 0.108, P = 0.021). CONCLUSION: The CAN is associated with the baPWV in patient with type 2 diabetes.

Comparison of Plaque Composition in Diabetic and Non-Diabetic Patients With Coronary Artery Disease Using Multislice CT Angiography

BACKGROUND AND OBJECTIVES: Plaque composition rather than degree of luminal narrowing may be predictive of future coronary events in high risk patients. The purpose of this study was to compare degree of plaque burden and composition with multislice computed tomography (MSCT) angiography between diabetic and non-diabetic patients. SUBJECTS AND METHODS: A total of 452 consecutive MSCT angiography examinations were performed between July 2007 and June 2009. Of these, the patients who underwent invasive coronary angiography were evaluated for the presence and type of atherosclerotic plaque and severity of luminal narrowing. RESULTS: Ninety two (46 in the diabetic group and 46 in the non-diabetic group) patients underwent both MSCT angiography and invasive coronary angiography. Among them, 30 patients (65.2%) in the diabetic group and 26 patients (56.5%) in the non-diabetic group had significant coronary narrowing on MSCT angiography. Sixteen patients (34.8%) in the diabetic group and 15 patients (32.6%) in non-diabetic group underwent coronary angioplasty and stenting. Forty-two patients (93.3%) in the diabetic group and 39 patients (88.6%) in the non-diabetic group had multiple types of coronary plaque (p=0.485). MSCT angiography was similar to conventional coronary angiography in its ability to predict significant coronary artery disease in that the area under the curve was 0.88 (95% confidence interval, 0.81 to 0.95). Diabetic patients had more mixed plaque compared with non-diabetic patients. CONCLUSION: Differences in coronary plaque composition between diabetic and non-diabetic patients can be determined noninvasively by MSCT angiography. In patients with diabetes, mixed plaque types contribute to the total plaque burden to a higher degree than in non-diabetic patients.

The Impact of Circadian Variation on 12-Month Mortality in Patients With Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: Although circadian variation in the onset of acute myocardial infarction (AMI) has been reported in a number of studies, not much is known about the impact of circadian variation on 12-month mortality. The aim of this study was to investigate the impact of circadian variation on 12-month mortality in patients with AMI. SUBJECTS AND METHODS: Eight hundred ninety two patients (mean age 67+/-12; 66.1% men) with AMI who visited Kyungpook National University Hospital from November 2005 to December 2007 were included in this study. Patients were divided into groups based on four 6-hours intervals: overnight (00:00-05:59); morning (06:00-11:59); afternoon (12:00-17:59) and evening (18:00-23:59). RESULTS: Kaplan-Meier survival curves showed 12-month mortality rates of 9.6%, 9.1%, 12.1%, and 16.7% in the overnight, morning, afternoon, evening-onset groups, respectively (p=0.012). Compared with the morning-onset AMI group, the serum creatinine levels (p=0.002), frequency of Killip class > or =3 (p=0.004), and prescription rate of diuretics (p=0.011) were significantly higher in the evening-onset AMI group, while the left ventricular ejection fraction (p=0.012) was significantly lower. The proportion of patients who arrived in the emergency room during routine duty hours was significantly lower in evening-onset groups irrespective of the presence or absence of ST-segment elevation (p<0.001). According to univariate analysis, the 12-month mortality rate in the evening group was significantly higher compared to the morning group (hazard ratio 1.998, 95% confidence interval 1.196 to 3.338, p=0.008). CONCLUSION: Patients with evening-onset AMI had poorer baseline clinical characteristics, and this might affect the circadian impact on 12-month mortality. Further studies are needed to clarify the role of circadian variation on the long-term outcome of AMI.

Electrocardiography Patterns and the Role of the Electrocardiography Score for Risk Stratification in Acute Pulmonary Embolism

BACKGROUND AND OBJECTIVES: Data on the usefulness of a combination of different electrocardiography (ECG) abnormalities in risk stratification of patients with acute pulmonary embolism (PE) are limited. We thus investigated 12-lead ECG patterns in acute PE to evaluate the role of the ECG score in risk stratification of patients with acute PE. SUBJECTS AND METHODS: One hundred twenty-five consecutive patients (63+/-14 years, 56 men) with acute PE who were admitted to Kyungpook National University Hospital between November 2001 and January 2008 were included. We analyzed ECG patterns and calculated the ECG score in all patients. We evaluated right ventricular systolic pressure (RVSP) (n=75) and RV hypokinesia (n=80) using echocardiography for risk stratification of acute PE patients. RESULTS: Among several ECG findings, sinus tachycardia and inverted T waves in V(1-4) (39%) were observed most frequently. The mean ECG score and RVSP were 7.36+/-6.32 and 49+/-21 mmHg, respectively. The ECG score correlated with RVSP (r=0.277, p=0.016). The patients were divided into two groups {high ECG-score group (n=38): ECG score >12 and low ECG-score group (n=87): ECG score < or =12} based on the ECG score, with the maximum area under the curve. RV hypokinesia was observed more frequently in the high ECG-score group than in the low ECG-score group (p=0.006). Multivariate analysis revealed that a high ECG score was an independent predictor of high RVSP and RV hypokinesia. CONCLUSION: Sinus tachycardia and inverted T waves in V(1-4) were commonly observed in acute PE. Moreover, the ECG score is a useful tool in risk stratification of patients with acute PE.

Examining the Relationship Between Triggering Activities and the Circadian Distribution of Acute Aortic Dissection

BACKGROUND AND OBJECTIVES: There are limited data examining triggering activities and circadian distribution at the onset of acute aortic dissection (AAD) in the context of diagnostic and anatomical classification. The aim of this study was to further investigate this relationship between triggering activities and circadian distribution at the onset of AAD according to diagnostic and anatomic classification. SUBJECTS AND METHODS: A total of 166 patients with AAD admitted to Kyungpook National University Hospital between July 2001 and June 2009 were included. To assess the influence of diagnostic and anatomical classification, we categorized the patients into intramural hematoma (IMH) group (n=67)/non-IMH group (n=99) and Stanford type A (AAD-A, n=94)/type B (AAD-B, n=72). To evaluate circadian distribution, the day was divided into four 6-hour periods: night (00-06 hours), morning (06-12 hours), afternoon (12-18 hours), and evening (18-00 hours). RESULTS: Most (72%) AAD episodes were related to physical (53%) and mental activities (19%), with about one-third occurring during the afternoon, and only 12% occurring at night. No differences in triggering activities or circadian distribution were observed among the groups. Waking hours including morning, afternoon, and evening correlated with triggering activities (p=0.003). These relationships were observed for the non-IMH (p=0.008) and AAD-B (p=0.003) cases. The remaining categories had similar relationships, but did not reach statistical significance. CONCLUSION: Our findings suggest differences in the relationship between triggering activities and the circadian distribution of the onset of AAD according to diagnostic and anatomical classification.

Gender Differences Among Korean Patients With Coronary Spasm

BACKGROUND AND OBJECTIVES: The gender differences among Korean patients with coronary spasm have not been defined. We thus determined the gender differences among Korean patients with coronary spasm. SUBJECTS AND METHODS: Patients with chest pain and/or syncope who were admitted to Kyungpook National University Hospital between January 2001 and August 2008 were included. Provocation of coronary vasospasm with intracoronary ergonovine maleate was performed when baseline coronary angiography showed no significant stenosis or there was a strong clinical suspicion of coronary spasm. The clinical characteristics were analyzed from 104 consecutive patients (56+/-9 years of age; 21 females) who were diagnosed with coronary spasm. RESULTS: Female patients were younger (52+/-7 vs. 57+/-10 years, p=0.046) with lower rates of smoking and alcohol consumption histories than male patients (19% vs. 65%, p<0.001; and 43% vs. 89%, p<0.001, respectively). The other clinical characteristics were not significantly different, except for the triglyceride levels. CONCLUSION: The majority of patients with coronary spasm were males who were smokers and alcohol consumers. The female patients had lower rates of smoking and alcohol consumption, and they were younger than the male patients. Further studies are needed to investigate the relevance of gender differences in the pathogenesis of coronary spasm.

Prognosis and Natural History of Drug-Related Bradycardia

BACKGROUND AND OBJECTIVES: The prognosis and natural history of bradycardia related to drugs such as beta-blockers and non-dihydropyridine calcium channel blockers are not well known. SUBJECTS AND METHODS: We retrospectively analyzed 38 consecutive patients (age 69+/-11, 21 women) with drug-related bradycardia (DRB) between March 2005 and September 2007. A drug-associated etiology for the bradycardia was established based on the medical history and patient response to drug discontinuation. The mean follow-up duration was 18+/-8 months. RESULTS: The initial electrocardiogram (ECG) showed sinus bradycardia (heart rate < or =40/min) in 13 patients, sinus bradycardia with junctional escape beats in 18 patients, and third-degree atrioventricular (AV) block in seven patients. Drug discontinuation was followed by resolution of bradycardia in 60% of patients (n=23). Among them, five (17.8%) patients resumed taking the culprit medication after discharge and none developed bradycardia again. Bradycardia persisted in 10 (26.3%) patients despite drug withdrawal, and a permanent pacemaker was implanted in seven of them. Third-degree AV block, QRS width, and bradycardia requiring temporary transvenous pacing were significantly associated with the bradycardia caused by drugs. CONCLUSION: Beta-blockers were the most common drugs associated with DRB. However, in one quarter of the cases the DRB was not associated with drugs; in these patients permanent pacemaker implantation should be considered.

The clinical significance of the differernce in left ventricular ejection fraction between rest and stress on gated myocardial perfusion SPECT / 대한내과학회지

BACKGROUND: Gated myocardial perfusion SPECT improved diagnostic accuracy of coronary artery disease and enabled us to observe motion and thickening of myocardial walls, ejection fraction as well as myocardial perfusion. Many studies suggested that there was a decrease of left ventricular ejection fraction (LVEF) at post-stress compared with that at rest gated myocardial perfusion SPECT (stunning). The objective of this retrospective study is to evaluate the clinical significance of the decrease of LVEF at post-stress gated myocardial perfusion SPECT by correlating with coronary angiographic finding. METHODS: Authors selected 41 patients who underwent exercise electrocardiography and gated myocardial perfusion SPECT between May, 2001 and May, 2002. The patients underwent coronary angiography within 6 months. The patients were divided into two groups, 16 patients in whom post-stress LVEF was >or=5% lower than rest (stunning group) and 25 patients in whom LVEF was not >or=5% lower than rest (non-stunning group). RESULTS: The number of patients with hyperlipidemia was higher in stunning group than in non-stunning group (50% vs 4%, p=0.001). The number of patients with angiographic stenoses >90% was significantly higher in stunning group than in non-stunning group (75% vs 28%, p=0.04). The number of patients with multi-vessel disease was also significantly higher in stunning group than in non-stunning group (75% vs 36%, p=0.015). CONCLUSION: The patients who had a decreased LVEF after stress (stunning) showed more severe coronary artery stenosis. This finding suggests that stunning may be an important additional indicator of underlying myocardial ischemia.

Prevalence rate and triggering factors of syncope in medical students / 대한내과학회지

BACKGROUND: Syncope is a sudden and brief loss of consciousness associated with a loss of postural tone, from which recovery is spontaneous. The most frequently identified causes of syncope are neurocardiogenic, cardiac, cerebrovascular and side effects of drugs. However, in many cases, it is not easy to make a diagnosis of syncope. The prevalence rate of syncope also is variable according to the nature of the study. We investigated the prevalence rate, characteristics and triggering factors of syncope in young medical students. METHODS: We contacted 400 medical students of Kyungpook National University, Daegu, Korea, and a questionnaire on the prevalence, triggering factors, and recurrence rate of syncope was handed out. The data from 379 medical student (male 168, female 211, mean age 22.3 years) were included for further analysis. RESULTS: Fifty-eight students (15.3%) experienced syncope and female students reported higher prevalence rate than male students (20.4 versus 8.9%, p=0.002). Among 58 students with syncopal history, 22 students (male 2, female 20) experienced recurrent syncope. The students who experienced recurrent syncope were younger at first syncope than those without recurrent syncope (15.0 versus 17.3 years, p=0.039). The triggering factors of syncope were prolonged standing, warm environment, immediate standing, tiredness, emotional upset, menstruation, and so on. CONCLUSION: The prevalence rate of syncope was 15% in medical student with mean age of 22.3 years. As the syncope in female and early onset syncope showed higher rate of recurrence, more attention may prevent recurrent syncope in these cases.

Changes in Heart Rate during and after Exercise Treadmill Test as Prognostic Factor in Cardiovascular Disease

BACKGROUND AND OBJECTIVES: Many studies have established risk factors for cardiovascular diseases. The Duke treadmill score has gained widespread acceptance for prognosis and diagnosis in cardiac diseases. Recently, changes in heart rate during and after exercise have also been studied to predict the prognosis of cardiac diseases. We examined the relationship between the incidence of cardiovascular events and exercise capacity, achievement of 85% maximal predicted heart rate (MPHR) or heart rate recovery (HRR) after a routine exercise treadmill test. SUBJECTS AND METHODS: We studied 88 patients with chest pain who were over the age of 30. They were referred for exercise treadmill test for assessment of chest pain and underwent symptom-limited, exercise test with a cool down period of 30 seconds. HRR was defined as the difference in heart rate between peak exercise and 1 minute after exercise. Delta heart rate (DHR) was defined as the difference in heart rate between resting and peak exercise. Other parameters in the exercise test were also measured. RESULTS: Cardiovascular events were found in 13 of the 88 patients. In the events group, age, peak heart rate in exercise, ST depression, maximal exercise capacity, HRR, DHR and achievement of 85% MPHR were all significant variables. There was a favorable prognosis in the patients with a value of HRR >22 beats/minute and a value of DHR >83 beats/minute. Even after adjusting for age, sex, ST depression and left ventricular hypertrophy, the parameters of maximal exercise capacity, HRR, DHR, and achievement of 85% MPHR remained predictive prognostic factors in cardiovascular events. CONCLUSION: Parameters in exercise treadmill test, such as maximal exercise capacity, HRR, DHR and achievement of 85% MPHR, appear to provide additional information and are important variables associated with the prediction of risk in cardiac events.

The Clinical Significance of Redefinition of Acute Myocardial Infarction by ESC/ACC

BACKGROUND AND OBJECTIVES: Epidemiologic studies and clinical trials require a more precise definition of acute myocardial infarction (AMI). The advent of sensitive and specific serologic biomarkers can identify those patients with small areas of myocardial necrosis. Acute myocardial infarction was redefined and approved by the ESC/ACC on September, 2000. To investigate the clinical implications of the revised criteria, the clinical features, the in-hospital outcomes and the 18 months outcomes were compared between the AMI patients who were diagnosed using the definition of the WHO criteria and those AMI patients added by the revised criteria. SUBJECTS AND METHODS: One hundred and seventy four consecutive patients diagnosed as AMI by the new criteria were included in the study. These patients with positive cardiac enzymes and ischemic symptoms or signs (n=174) were divided into two groups. The patients of group 1 (n=105) were the patients who were diagnosed with AMI by the WHO criteria, and the patients of group 2 (n=69), were the additional patients who were diagnosed with AMI only by the new criteria. RESULTS: The new criteria of AMI by ESC/ACC increased the numbers of AMI by 66%. As compared with group 1, women and patients with hypertension and a past history of ischemic heart disease were more common in group 2 (p<0.05). Percutaneous coronary intervention (PCI) was used less frequently and Angiotensin converting enzyme inhibitors (ACEIs), beta blockers and aspirin were prescribed less frequently in group 2. The total cardiac events and cumulative survival rate in group 1 were higher than in Group 2 (12.3% vs 7.2%, 89% vs 94%, respectively) but these differences were not statistically significant. CONCLUSION: The new criteria results in a substantial increase in the diagnosis of AMI, and the new criteria helps identify patients who were missed by the old criteria. The patients with AMI who were added by the new criteria had a similar risk of adverse outcome.

A Case of Left Main Coronary Stenting for Acute Myocardial Infarction Complicated by Ascending Aortic Dissection

We report here on a case of ascending aortic dissection combined with anterior myocardial infarction that was caused by a retrograde dissection into the left main coronary trunk and proximal left anterior descending artery. We successfully treated this with stenting of the left main coronary artery and proximal left anterior descending artery, and this allowed for the definitive surgical correction. Stenting a collapsed left main coronary artery can be lifesaving procedure and serve as a bridge to surgery.

The Prognostic Value of Mean Platelet Volume in Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: An increased platelet volume is associated with increased platelet reactivity, and may influence the outcome following a myocardial infarction. SUBJECTS AND METHODS: One hundred patients with acute myocardial infarction, who visited Kyungpook National University Hospital between 2001 January and 2001 December, were included in this study. To determine the mean platelet volume (MPV), blood samples, taken at the time of arrival, were analyzed in an automated haematology analysis system (CELL-DYN3000, ABBOTT, USA). EDTA in the blood bottles was used as an anticoagulant. All samples were processed within 30 minutes of venipuncture, to avoid bias due to platelet swelling. The patients were followed for one year for readmission due to acute coronary syndrome, congestive heart failure or death. To stratify the prognostic value of the MPV, the patients were divided into 4 equal groups according to the percentiles of the platelet volume. RESULTS: Eight patients died, and 20 were readmitted due to acute coronary syndrome or congestive heart failure. The MPV is not a significant predictor of death. However, in the prediction of MACE, death and readmission, the MPV and age were significant factors (p 8.8fL) had a 7 times greater risk of MACE than the lowest quartile group (MPV<7.4 fL). CONCLUSION: The MPV measured in the emergency room is a significant predictor of MACE with an acute myocardial infarction. Therefore, patients with a large MPV might require more intensive, closely controlled treatment strategies for secondary prevention.