Jong Hyun Kim

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

OBJECTIVESnWe 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.nnnBACKGROUNDnIntensive 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.nnnMETHODSnWe 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.nnnRESULTSnStatin 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.nnnCONCLUSIONSnStatin therapy in patients with AMI with LDL-C levels below 70 mg/dl was associated with improved clinical outcome.

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?

BACKGROUNDnThere 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).nnnMETHODSnThe 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.nnnRESULTSnClinical 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).nnnCONCLUSIONSnPatients 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.

What is optimal revascularization strategy in patients with multivessel coronary artery disease in non-ST-elevation myocardial infarction? Multivessel or culprit-only revascularization

BACKGROUNDnIn patients with non-ST-elevation myocardial infarction (NSTEMI), current guidelines did not recommend optimal revascularization management in multivessel coronary artery disease. We compared clinical outcomes between multivessel revascularization and culprit-only revascularization in this setting.nnnMETHODSnA total of 1919 patients with multivessel disease (1011 patients; multivessel revascularization group, 908 patients; culprit-only revascularization group) diagnosed as NSTEMI was enrolled in a nationwide prospective Korea Acute Myocardial Infarction Registry (KAMIR) from November 2005 to January 2008. The primary end-points were major adverse cardiac events (MACE), all-causes of deaths, myocardial infarction (MI), and repeated percutaneous coronary intervention (PCI) during 1-year clinical follow-up. Also, subgroup analysis was performed in patients with high TIMI (Thrombolysis In Myocardial Infarction) risk score (≥ 4) to find efficacy of multivessel PCI in high-risk patients.nnnRESULTSnBaseline clinical characteristics and the risk factors of coronary artery disease were similar between both groups. In angiography, three-vessel lesion was more presented in the multivessel group (46.1% vs. 40.9%, p = 0.024) and rates of left anterior descending and left main stem coronary artery as culprit vessel were higher in the multivessel group (p = 0.003 and p = 0.001 respectively). In-hospital mortality was higher in the culprit-only group (1.4% vs. 2.9%, p = 0.025). Primary end-points occurred in 241 patients (15.5%) during 1-year follow-up. Multivessel revascularization reduced MACEs [hazard ratio (HR) 0.658, 95% confidence interval (CI) 0.45 to 0.96, p = 0.031], death or myocardial infarction (HR 0.58, 95% CI 0.35 to 0.97, p = 0.037) and non-target vessel revascularization (HR 0.44, 95% CI 0.24 to 0.81, p = 0.008). There were no significant differences in target lesion revascularization (TLR; HR 1.38, 95% CI 0.51 to 3.71, p = 0.529) and target vessel revascularization (TVR; HR 0.28, 95% CI 0.05 to 1.47, p = 0.131). In subgroup analysis in patients with a higher TIMI risk score, similar results were presented.nnnCONCLUSIONnMultivessel revascularization in multivessel coronary artery disease presenting with NSTEMI showed better clinical outcomes without significant in-stent restenosis and progression of diseased-vessel compared to culprit-only revascularization.

A new risk score system for the assessment of clinical outcomes in patients with non-ST-segment elevation myocardial infarction

BACKGROUND AND OBJECTIVESnPrediction for long-term clinical outcomes in patients with non-ST elevation acute coronary syndrome is important as well as early risk stratification. The aim of this study is to develop a simple assessment tool for better early bedside risk stratification for both short- and long-term clinical outcomes.nnnSUBJECTS AND METHODSn2148 patients with non-ST-segment elevation myocardial infarction (NSTEMI) (64.9±12.2xa0years, 35.0% females) were enrolled in a nationwide prospective Korea Acute Myocardial Infarction Registry (KAMIR). A new risk score was constructed using the variables related to one year mortality: TIMI risk index (17.5-30: 1 point, >30: 2 points), Killip class (II: 1 point, >II: 2 points) and serum creatinine (≥1.5xa0mg/dL: 1 point), based on the multivariate-adjusted risk relationship. The new risk score system was compared with the Global Registry of Acute Coronary Events (GRACE) and TIMI risk scores during a 12-month clinical follow-up.nnnRESULTSnDuring a one year follow-up, all causes of death occurred in 362 patients (14.3%), and 184 (8.6%) patients died in the hospital. The new risk score showed good predictive value for one year mortality. The accuracy for in-hospital and one year post-discharge mortality rates, the new risk score demonstrated significant differences in predictive accuracy when compared with TIMI and GRACE risk scores.nnnCONCLUSIONnA new risk score in the present study provides simplicity with accuracy simultaneously for early risk stratification, and also could be a powerful predictive tool for long-term prognosis in NSTEMI.

Hospital discharge risk score system for the assessment of clinical outcomes in patients with acute myocardial infarction (Korea Acute Myocardial Infarction Registry [KAMIR] Score)

Assessment of risk at time of discharge could be a useful tool for guiding postdischarge management. The aim of this study was to develop a novel and simple assessment tool for better hospital discharge risk stratification. The study included 3,997 hospital-discharged patients with acute myocardial infarction who were enrolled in the nationwide prospective Korea Acute Myocardial Infarction Registry-1 (KAMIR-1) from November 2005 through December 2006. The new risk score system was tested in 1,461 hospital-discharged patients who were admitted from January 2007 through January 2008 (KAMIR-2). The new risk score system was compared to the Global Registry of Acute Coronary Events (GRACE) postdischarge risk model during a 12-month clinical follow-up. During 1-year follow-up, all-cause death occurred in 228 patients (5.7%) and 81 patients (5.5%) in the development and validation cohorts, respectively. The new risk score (KAMIR score) was constructed using 6 independent variables related to the primary end point using a multivariable Cox regression analysis: age, Killip class, serum creatinine, no in-hospital percutaneous coronary intervention, left ventricular ejection fraction, and admission glucose based on multivariate-adjusted risk relation. The KAMIR score demonstrated significant differences in its predictive accuracy for 1-year mortality compared to the GRACE score for the developmental and validation cohorts. In conclusion, the KAMIR score for patients with acute myocardial infarction is a simpler and better risk scoring system than the GRACE hospital discharge risk model in prediction of 1-year mortality.

Comparison of Outcomes Between Zotarolimus- and Sirolimus-Eluting Stents in Patients With ST-Segment Elevation Acute Myocardial Infarction

Zotarolimus-eluting stents (ZESs) demonstrated greater in-segment late luminal loss and in-segment binary restenosis rates compared to sirolimus-eluting stents (SESs) in several studies. However, no data are available in direct comparison between the clinical outcomes of the 2 stents in unselected patients with ST-segment elevation acute myocardial infarction (STEMI). The aim of the present study was to compare the clinical outcomes of ZESs and SESs in real-world patients with STEMI. A total of 873 patients with STEMI (306 patients in the ZES group and 567 patients in the SES group) were enrolled in a nationwide prospective Korea Acute Myocardial Infarction Registry (KAMIR) from January 2007 to January 2008. The primary end points were major adverse cardiac events, a composite of all causes of death, myocardial infarction, and target lesion revascularization during a 12-month clinical follow-up. During 1 year of follow-up, the primary end points occurred in 140 patients (16.0%). The use of glycoprotein IIb/IIIa inhibitors and the occurrence of multivessel disease were more common in the SES group. The SES group had a significantly lower incidence of major adverse cardiac events (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.07 to 2.16, p = 0.02), target lesion revascularization (HR 2.16, 95% CI 1.01 to 4.59, p = 0.046), and target vessel revascularization (HR 2.24, 95% CI 1.18 to 4.24, p = 0.013). However, no significant differences were found in death or myocardial infarction (HR 1.37, 95% CI 0.91 to 2.05, p = 0.129). In conclusion, SESs provided superior angiographic outcomes, translating into better clinical outcomes and negating any change in STEMI patient safety profiles compared to ZESs.

Comparison of Outcomes of Patients With Painless Versus Painful ST-Segment Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

There are few data available on the prognosis of painless ST-segment elevation myocardial infarction (STEMI). The aim of this study was to determine the incidence, clinical characteristics, and outcomes of painless STEMI. We analyzed the Korea Acute Myocardial Infarction Registry (KAMIR) study, which enrolled 7,288 patients with STEMI (61.8 ± 12.8 years old, 74% men; painless STEMI group, n = 763; painful STEMI group, n = 6,525). End points were in-hospital mortality and 1-year major adverse cardiac events (MACEs). Patients with painless STEMI were older and more likely to be women, nonsmokers, diabetic, and normolipidemic and to have a higher Killip class. The painless group had more in-hospital deaths (5.9% vs 3.6%, p = 0.026) and 1-year MACEs (26% vs 19%, p = 0.002). In Cox proportional hazards analysis, hypotension (hazard ratio [HR] 4.40, 95% confidence interval [CI] 1.41 to 13.78, p = 0.011), low left ventricular ejection fraction (HR 3.12, 95% CI 1.21 to 8.07, p = 0.019), and a high Killip class (HR 3.48, 95% CI 1.19 to 10.22, p = 0.023) were independent predictors of 1-year MACEs in patients with painless STEMI. In conclusion, painless STEMI was associated with more adverse outcomes than painful STEMI and late detection may have contributed significantly to total ischemic burden. These results warrant more investigations for methodologic development in the diagnosis of silent ischemia and painless STEMI.

Clinical impact of thrombus aspiration during primary percutaneous coronary intervention: Results from Korea Acute Myocardial Infarction Registry

BACKGROUNDnThe role of thrombus aspiration (TA) as an adjunct to primary percutaneous coronary intervention (PPCI) remains a matter of controversy.nnnMETHODS AND RESULTSnA total of 2105 patients enrolled in the nationwide prospective Korea Acute Myocardial Infarction Registry, a cohort of 745 (35.4%) patients who underwent TA during PPCI was compared with 1360 (64.6%) patients who underwent conventional PCI without TA. Clinical outcomes at 12-months of overall enrolled patients and subgroups according to key variables were assessed using Cox regression models adjusted by propensity score. Although there was no significant difference among overall patients, in subgroup analyses, administration of glycoprotein (GP) IIb/IIIa inhibitor during PPCI [adjusted hazard ratio (HR) 0.329, 95% confidence interval (CI) 0.126-0.860, p=0.023] and left anterior descending (LAD) as a culprit lesion (adjusted HR 0.516, 95% CI 0.275-0.971, p=0.040) were the settings, in which TA was associated with a lower major adverse cardiac events (MACE) rate compared with non-TA.nnnCONCLUSIONSnAlthough TA does not improve clinical outcomes in overall patients who underwent PPCI, TA for LAD occlusion improves 12-month MACE. Furthermore, use of GP IIb/IIIa inhibitor with TA has a synergistic effect on clinical outcomes.

Clinical Characteristics and Outcomes of Acute ST-Segment Elevation Myocardial Infarction in Younger Korean Adults

Background and Objectives This study aims to investigate the clinical features, angiographic findings, and outcomes of younger Korean ST-segment elevation myocardial infarction (STEMI) patients. Subjects and Methods We analyzed major adverse cardiac events (MACE) in the Korea Acute Myocardial Infarction Registry from November 2005 to October 2010. The registered patients were divided into two groups; young age group (<65 years) and old age group (≥65 years). Results The young age group included 5281 patients (age, 53±7.8 years), and the old age group included 4896 patients (age, 74.3±6.5 years). Male gender, smoking, family history, dyslipidemia, and metabolic syndrome were more frequently observed in the young age group than in the old age group (89.5% vs. 59.3%, p<0.001; 77.3% vs. 47.2%, p<0.001; 11% vs. 4.6%, p<0.001; 11.2% vs. 7.7%, p<0.001; 67.6% vs. 62.9%, p<0.001). Most of the young Korean adults with STEMI complained of typical chest pain (89.8%), and they had a shorter symptom-to-door time (12±53.2 hours vs. 17.3±132 hours, p=0.010). The young age group showed a favorable prognosis, which was represented by the MACE, compared with the old age group at one month (1.8% vs. 2.8%, p=0.028), six months (6.8% vs. 8.2%, p<0.001), and twelve months (10.1% vs. 11.9%, p=0.025). However, there was no significant difference in the adjusted MACE rate at one month {hazard ratio (HR) 0.95, 95% confidence interval (CI) 0.60-1.51, p=0.828} and twelve months (HR 0.86, 95% CI 0.68-1.10, p=0.233). Conclusion Younger Korean adults with STEMI have clinical outcomes similar to old aged patients, and therefore, they should be treated intensively like the elderly patients.