Shung Chull Chae

Independent and incremental prognostic value of exercise single-photon emission computed tomographic (SPECT) thallium imaging in coronary artery disease

OBJECTIVES The objective of this study was to examine the independent and incremental prognostic value of exercise single-photon emission computed tomographic (SPECT) thallium imaging in patients with angiographically defined coronary artery disease. BACKGROUND Previous studies showed the importance of exercise thallium-201 in risk stratification. However, most of these studies used planar imaging techniques. METHODS Follow-up data were obtained in 316 medically treated patients with coronary artery disease. Cox proportional hazards regression models were used to examine the independent and incremental prognostic values of clinical, exercise, thallium and cardiac catheterization data. RESULTS There were 35 events (cardiac death or nonfatal myocardial infarction) at a mean follow-up time of 28 months. Univariate analysis showed that gender (chi-square = 5.1), exercise work load (chi-square = 3.1), extent of coronary artery disease and left ventricular ejection fraction (chi-square = 14.8) and thallium variables (chi-square = 22.7) were prognostically important. The thallium data provided incremental prognostic value to catheterization data (chi-square = 33.7, p < 0.01). The extent of the perfusion abnormality was the single best predictor of prognosis (chi-square = 14). Patients with a large perfusion abnormality had a worse prognosis than that of patients with a mild or no abnormality (Mantel-Cox statistics = 10.6, p < 0.001). CONCLUSIONS In medically treated patients with coronary artery disease, exercise SPECT thallium imaging provides independent and incremental prognostic information even when catheterization data are available. The extent of the perfusion abnormality is the single most important prognostic predictor.

Identification of extensive coronary artery disease in women by exercise single-photon emission computed tomographic (SPECT) thallium imaging

OBJECTIVES The aim of this study was to examine the ability of exercise single-photon emission computed tomographic (SPECT) thallium imaging to identify high risk women with left main or three-vessel coronary artery disease using a stepwise discriminant analysis. BACKGROUND Previous studies have used statistical methods to identify high risk men with coronary artery disease. Only limited data are available in women. METHODS Exercise SPECT thallium imaging and coronary arteriography were performed for evaluation of chest pain in 243 women. Group 1 comprised 58 women with left main or three-vessel coronary disease and group 2 comprised 185 women with no or one- or two-vessel disease. Stepwise discriminant analysis was used to determine predictors of left main or three-vessel disease. RESULTS On univariate analysis, women in group 1 were older (p < 0.03) and had a lower exercise work load (p < 0.02), lower exercise heart rate (p < 0.004), higher prevalence rate of diabetes mellitus (p < 0.0003) and more multivessel thallium abnormality (p < 0.0001) compared with women in group 2. On multivariate analysis, only multivessel thallium abnormality (F = 43) and exercise heart rate (F = 6) were independent predictors of left main or three-vessel coronary disease. A model based on these two variables separated the women into three risk groups: 99 patients with 9%, 70 patients with 23% and 74 patients with 45% prevalence of left main or three-vessel disease (p < 0.0001). CONCLUSIONS High risk women with left main or three-vessel coronary disease can be identified by exercise SPECT thallium imaging.

Characteristics, Outcomes and Predictors of Long-Term Mortality for Patients Hospitalized for Acute Heart Failure: A Report From the Korean Heart Failure Registry

Background and Objectives Acute heart failure (AHF) is associated with a poor prognosis and it requires repeated hospitalizations. However, there are few studies on the characteristics, treatment and prognostic factors of AHF. The aims of this study were to describe the clinical characteristics, management and outcomes of the patients hospitalized for AHF in Korea. Subjects and Methods We analyzed the clinical data of 3,200 hospitalization episodes that were recorded between June 2004 and April 2009 from the Korean Heart Failure (KorHF) Registry database. The mean age was 67.6±14.3 years and 50% of the patients were female. Results Twenty-nine point six percent (29.6%) of the patients had a history of previous HF and 52.3% of the patients had ischemic heart disease. Left ventricular ejection fraction (LVEF) was reported for 89% of the patients. The mean LVEF was 38.5±15.7% and 26.1% of the patients had preserved systolic function (LVEF ≥50%), which was more prevalent in the females (34.0% vs. 18.4%, respectively, p<0.001). At discharge, 58.6% of the patients received beta-blockers (BB), 53.7% received either angiotensin converting enzyme-inhibitors or angiotensin receptor blockers (ACEi/ARB), and 58.4% received both BB and ACEi/ARB. The 1-, 2-, 3- and 4-year mortality rates were 15%, 21%, 26% and 30%, respectively. Multivariate analysis revealed that advanced age {hazard ratio: 1.023 (95% confidence interval: 1.004-1.042); p=0.020}, a previous history of heart failure {1.735 (1.150-2.618); p=0.009}, anemia {1.973 (1.271-3.063); p=0.002}, hyponatremia {1.861 (1.184-2.926); p=0.007}, a high level of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) {3.152 (1.450-6.849); p=0.004} and the use of BB at discharge {0.599 (0.360-0.997); p=0.490} were significantly associated with total death. Conclusion We present here the characteristics and prognosis of an unselected population of AHF patients in Korea. The long-term mortality rate was comparable to that reported in other countries. The independent clinical risk factors included age, a previous history of heart failure, anemia, hyponatremia, a high NT-proBNP level and taking BB at discharge.

Benefit of Early Statin Therapy in Patients With Acute Myocardial Infarction Who Have Extremely Low Low-Density Lipoprotein Cholesterol

OBJECTIVES We investigated whether statin therapy could be beneficial in patients with acute myocardial infarction (AMI) who have baseline low-density lipoprotein cholesterol (LDL-C) levels below 70 mg/dl. BACKGROUND Intensive lipid-lowering therapy with a target LDL-C value <70 mg/dl is recommended in patients with very high cardiovascular risk. However, whether to use statin therapy in patients with baseline LDL-C levels below 70 mg/dl is controversial. METHODS We analyzed 1,054 patients with AMI who had baseline LDL-C levels below 70 mg/dl and survived at discharge from the Korean Acute MI Registry between November 2005 and December 2007. They were divided into 2 groups according to the prescribing of statins at discharge (statin group n = 607; nonstatin group n = 447). The primary endpoint was the composite of 1-year major adverse cardiac events, including death, recurrent MI, target vessel revascularization, and coronary artery bypass grafting. RESULTS Statin therapy significantly reduced the risk of the composite primary endpoint (adjusted hazard ratio [HR]: 0.56; 95% confidence interval [CI]: 0.34 to 0.89; p = 0.015). Statin therapy reduced the risk of cardiac death (HR: 0.47; 95% CI: 0.23 to 0.93; p = 0.031) and coronary revascularization (HR: 0.45, 95% CI: 0.24 to 0.85; p = 0.013). However, there were no differences in the risk of the composite of all-cause death, recurrent MI, and repeated percutaneous coronary intervention rate. CONCLUSIONS Statin therapy in patients with AMI with LDL-C levels below 70 mg/dl was associated with improved clinical outcome.

A multicentre cohort study of acute heart failure syndromes in Korea: Rationale, design, and interim observations of the Korean Acute Heart Failure (KorAHF) registry

The Korean Acute Heart Failure registry (KorAHF) aims to evaluate the clinical characteristics, management, hospital course, and long‐term outcomes of patients hospitalized for acute heart failure syndrome (AHFS) in Korea.

Early- and late-term clinical outcome and their predictors in patients with ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction

BACKGROUNDS The disparity between ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) remains controversial. We compared clinical outcomes and prognostic factors between STEMI and NSTEMI using large-scale registry data. METHODS We recruited 28,421 patients with STEMI (n=16,607) and NSTEMI (n=11,814) between November 2005 and April 2010 from a nationwide registry in Korea. We performed landmark analysis of cardiac death, recurrent acute myocardial infarction (re-AMI), revascularization, and major adverse cardiac events (MACE) at 30 days (early term) and 1 year (late term) after admission. RESULTS Patients with NSTEMI had a greater number of co-morbidities than STEMI patients. Early term MACE (6.9% vs. 4.5%, p<0.001) and cardiac death (6.1% vs. 3.7%, p<0.001) were higher in STEMI patients. However, late-term MACE (8.0% vs. 9.1%, p=0.007), cardiac death (1.9% vs. 2.6%, p=0.001), and re-AMI (0.6% vs. 1.3%, p<0.001) were lower in the STEMI group. The independent predictors of cardiac death were old age, renal dysfunction, LV dysfunction, Killip class, post-thrombolysis in myocardial infarction (TIMI) flow, and major bleeding in both groups. Female gender, previous ischemic heart disease, diabetes, current smoking, multivessel disease, and body mass index were MI type- or time-dependent predictors. CONCLUSION The STEMI group displayed poor early term clinical outcome, whereas the NSTEMI group displayed poor late-term clinical outcome. The STEMI and NSTEMI groups had different predictor profiles for cardiac death, suggesting that different strategies are required for improving the late-term outcome of STEMI and NSTEMI patients.

Predictors of Six-Month Major Adverse Cardiac Events in 30-Day Survivors After Acute Myocardial Infarction (from the Korea Acute Myocardial Infarction Registry)

Little is known about risk factors for 6-month major adverse cardiac events (MACEs) in 30-day survivors after acute myocardial infarction (AMI). We investigated predictors of 6-month MACE in 30-day survivors after MI from the Korea Acute Myocardial Infarction Registry (KAMIR). From November 2005 to January 2008, 9,706 patients (6,983 men, mean age 64.0 +/- 12.4 years) who survived >30 days after AMI were analyzed. The primary end point was 6-month MACEs including death, MI, and revascularization. During 6-month follow-up, 317 patients (3.2%) had MACEs including 66 (0.6%) deaths, 23 (0.2%) recurrent MIs, and 218 (2.2%) revascularizations. In multivariate logistic regression analysis, factors reflecting demographics (body mass index), severity of left ventricular systolic dysfunction (Killip class >I, in-hospital cardiogenic shock, use of intra-aortic balloon pump), residual myocardial ischemia (previous coronary heart disease, multivessel disease), and electrical instability (ventricular tachycardia/ventricular fibrillation on admission) were independent predictors of 6-month MACEs after adjustment for clinical, angiographic, and procedural data. Plasma level of N-terminal pro-B-type natriuretic peptide provided an additional prognostic value predicting 6-month MACEs. In conclusion, this study provides useful prognostic information for clinicians to advise patients who have survived the acute phase of MI. More intensive management is needed in survivors after MI with these high-risk features.

Obesity paradox in Korean patients undergoing primary percutaneous coronary intervention in ST-segment elevation myocardial infarction

The effect of body mass index (BMI) on outcomes after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is not well known. In patients registered in the Korean Acute Myocardial Infarction Registry (KAMIR) between November 2005 and November 2007, 3824 STEMI patients who arrived at hospital within 12h after onset of chest pain and underwent primary PCI were analyzed, and divided into four groups according to their BMI: underweight (BMI<18.5 kg/m(2), n=129); normal weight (18.5 < or =BMI <23.0 kg/m(2), n=1253); overweight (23.0 < or =BMI <27.5 kg/m(2), n=1959); and obese (BMI > or =27.5 kg/m(2), n=483). In-hospital mortality, revascularization in 1 year, mortality in 1 year, and overall mortality were compared between groups. Overweight and obese group were significantly younger, had normal left ventricular ejection fraction, and were more likely to be men with a higher incidence of hypertension, diabetes, and hyperlipidemia. There were no significant differences in symptom-to-door time and door-to-balloon time between groups. Obese patients had significantly lower in-hospital and overall mortalities. Major adverse cardiac events showed a bimodal pattern. Obese STEMI patients treated with primary PCI were associated with lower mortality, which may be explained by better use of medical treatment, hemodynamic stability, and younger age.

Are patients with angiographically near-normal coronary arteries who present as acute myocardial infarction actually safe?

BACKGROUND There is a paucity of data concerning the clinical outcome of patients presenting with acute myocardial infarction (AMI) and near-normal coronary angiograms. The purpose of this study was to evaluate the clinical outcome and the prognosis of the patients with near-normal coronary angiograms who were registered in the Korean Acute Myocardial Infarction Registry (KAMIR). METHODS The subjects were divided into three groups according to findings from coronary angiograms performed between September 2005 and November 2006. Among 8510 consecutive AMI patients, 372 patients (Group I) had near-normal coronary arteries, 6136 patients (Group II) had one- or two-vessel disease, and 2002 patients (Group III) had three-vessel or left main disease. RESULTS Clinical characteristics, in-hospital mortality, and major cardiac adverse events (MACE) were analyzed. Group I was younger, had the lower prevalence of DM, and showed the higher percentage of previous angina history compared to the other two groups. Group III showed a higher incidence of in-hospital mortality, but there was no significant difference between Group I and Group II (2.6% in Group II and 2.2% in Group I, p=0.952). Furthermore, MACE at 1 month, 6 months and 12 months revealed no significant difference between Groups I and II (12 month MACE: 7.8% in Group I and 12.2% in Group II, p=0.359). CONCLUSIONS Patients with near-normal coronary angiograms had similar clinical outcomes and prognosis compared with one- or two-vessel diseased patients presenting with an acute myocardial infarction.

Sex Differences in Management and Mortality of Patients With ST-Elevation Myocardial Infarction (from the Korean Acute Myocardial Infarction National Registry)

There has been controversy over the disparity between men and women with regard to the management and prognosis of acute myocardial infarction. Analyzing nationwide multicenter prospective registries in Korea, the aim of this study was to determine whether female gender independently imposes a risk for mortality. Data from 14,253 patients who were hospitalized for ST-segment elevation myocardial infarction from November 2005 to September 2010 were extracted from registries. Compared to men, women were older (mean age 56 ± 12 vs 67 ± 10 years, p < 0.001), and female gender was associated with a higher frequency of co-morbidities, including hypertension, diabetes, and dyslipidemia. Women had longer pain-to-door time and more severe hemodynamic status than men. All-cause mortality rates were 13.6% in women and 7.0% in men at 1 year after the index admission (hazard ratio for women 2.01, 95% confidence interval 1.80 to 2.25, p < 0.001). The risk for death after ST-segment elevation myocardial infarction corresponded highly with age. Although the risk remained high after adjusting for age, further analyses adjusting for medical history, clinical performance, and hemodynamic status diminished the gender effect (hazard ratio 1.00, 95% confidence interval 0.86 to 1.17, p = 0.821). Propensity score matching, as a sensitivity analysis, corroborated the results. In conclusion, this study shows that women have a comparable risk for death after ST-segment elevation myocardial infarction as men. The gender effect was accounted for mostly by the womens older age, complex co-morbidities, and severe hemodynamic conditions at presentation.