Characteristics of non-culprit plaques in acute coronary syndrome patients with calcified plaque at the culprit lesion.

OBJECTIVES: To investigate the non-culprit plaques (NCPs) characteristics in acute coronary syndrome (ACS) patients with calcified plaques (CP). BACKGROUND: Recently, a new in vivo classification of calcified culprit plaques in patients with ACS was proposed. Characteristics of NCPs in this group of patients are unknown. METHODS: A total of 692 NCPs from 492 ACS patients were retrospectively compared based on the culprit plaque phenotype: 71 from CP patients, 383 from plaque rupture (PR) patients, 238 from plaque erosion (PE) patients. RESULTS: NCPs of CP patients had greater maximal calcium thickness, wider calcium arc, longer calcium length, and greater calcium index, compared to PR or PE patients (CP vs. PR: all p < .001, CP vs. PE: all p < .001). Thin-cap fibroatheroma was less prevalent (p = .023), fibrous cap was thicker (p = .035), and mean lipid arc was narrower in CP than in PR (p < .001). CONCLUSIONS: In conclusion, NCPs of CP patients had greater calcium burden and less vulnerability. This information may help to better understand the underlying mechanisms of ACS and to develop strategy for tailored management.

Circadian variations in pathogenesis of ST-segment elevation myocardial infarction: an optical coherence tomography study.

Previous studies have reported a circadian variation in the onset of ST-segment elevation myocardial infarction (STEMI). However, underlying mechanisms for the circadian variation have not been fully elucidated. We investigated the relationship between onset of STEMI and the underlying pathology using optical coherence tomography (OCT). Patients with a diagnosis of STEMI were selected from a multicenter OCT registry. Patients were divided into 4 groups based on the estimated time of onset (00:00-05:59, 06:00-11:59, 12:00-17:59, or 18:00-23:59). Underlying pathologies of MI (plaque rupture, plaque erosion, and calcified plaque) were compared among the 4 groups. Among 648 patients, plaque rupture was diagnosed in 386 patients (59.6%), plaque erosion in 197 patients (30.4%), and calcified plaque in 65 patients (10.0%). A marked circadian variation was detected in the incidence of plaque rupture with a peak at 09:00, whereas it was not evident in plaque erosion or calcified plaque. The probability of plaque rupture significantly increased in the periods of 06:00-11:59 [odds ratio (OR) 2.13, 95% confidence interval (CI) 1.30-3.49, p = 0.002] and 12:00-17:59 (OR 2.10, 95% CI 1.23-3.58, p = 0.005), compared to the period of 00:00-05:59. This circadian pattern was observed only during weekdays (p = 0.010) and it was not evident during the weekend (p = 0.742). Plaque rupture occurred most frequently in the morning and this circadian variation was evident only during weekdays. Acute MI caused by plaque rupture may be related to catecholamine surge.

Effects of Asian dust-derived particulate matter on ST-elevation myocardial infarction: retrospective, time series study.

BACKGROUND: Dust storms affect human health by impairing visibility and promoting interactions with microscopic organisms, such as bacteria and fungi. Although ST-elevation MI (STEMI) and non-ST-elevation MI (NSTEMI) differ mechanistically, few studies have investigated the incidence of cardiovascular diseases according to infarction type; these studies have yielded inconsistent findings. This study aimed to examine whether PM size (< 2.5 µm (PM2.5) and < 10 µm (PM10)) modifies the effect of Asian dust on acute myocardial infarction (AMI), with separate analyses for STEMI and NSTEMI. METHODS: MI-related data from 9934 emergency visits were collected from the Korea AMI Registry from 2005 to 2017. Asian dust events were defined as days with visibility of ≤10 km. Generalized linear models were used to analyze data with natural cubic splines. To examine potential modifiers, analyses were stratified by age, smoking status, and body mass index (BMI). RESULTS: No significant associations were observed between Asian dust and AMI. By adjusting for different lag structures, a significant effect was exclusively observed in STEMI. For moving average lags, the largest value at lag 5 (relative risk [RR] 1.083; 95% confidence interval [CI], 1.007-1.166) for single and lags 0-7 (RR 1.067; 95% CI: 1.002-1.136) was observed for PM2.5; for PM10, the largest significant effect was observed at lag 4 (RR 1.075; 95% CI: 1.010-1.144) for single and lags 0-7 (RR 1.067; 95% CI: 1.002-1.136). RRs were significantly higher in < 65-year-olds than in ≥65-year-olds. Additionally, RRs between the BMI < 25 and BMI ≥ 25 groups were not different; statistically significant effects were observed for concentration at lags 0-5 (RR: 1.073; 95% CI: 1.002-1.150) and lags 0-6 (RR: 1.071; 95% CI: 1.001-1.146) in the BMI < 25 group. A negative exposure-response association was observed between daily average visibility-adjusted PM and STEMI and daily average visibility-adjusted PM in < 65-year-olds. CONCLUSIONS: Reducing PM2.5 and PM10 emissions, particularly during the days of Asian dust, may be crucial and reduce STEMI and AMI incidence among < 65-year-olds. These results indicate that the Asian dust alarm system needs revision to protect vulnerable populations.

Intravascular modality-guided versus angiography-guided percutaneous coronary intervention in acute myocardial infarction.

BACKGROUND: Few data are available for current usage patterns of intravascular modalities such as intravascular ultrasound (IVUS), optical coherence tomography (OCT), and fractional flow reserve (FFR) in acute myocardial infarction (AMI). Moreover, patient and procedural-based outcomes related to intravascular modality guidance compared to angiography guidance have not been fully investigated yet. METHODS: We examined 11,731 patients who underwent percutaneous coronary intervention (PCI) from the Korea AMI Registry-National Institute of Health database. Patient-oriented composite endpoint (POCE) was defined as all-cause death, any infarction, and any revascularization. Device-oriented composite endpoint (DOCE) was defined as cardiac death, target-vessel reinfarction, and target-lesion revascularization. RESULTS: Overall, intravascular modalities were utilized in 2,659 (22.7%) patients including 2,333 (19.9%) IVUS, 277 (2.4%) OCT, and 157 (1.3%) FFR. In the unmatched cohort, POCE (5.4 vs. 8.5%; adjusted hazard ratio (HR) 0.75; 95% confidence interval (CI) 0.61-0.93; p = .008) and DOCE (4.6 vs. 7.4%; adjusted HR 0.77; 95% CI 0.61-0.97; p = .028) were significantly lower in intravascular modality-guided PCI compared with angiography-guided PCI. In the propensity-score-matched cohorts, POCE (5.9 vs. 7.7%; HR 0.74; 95% CI 0.60-0.92; p = .006) and DOCE (5.0 vs. 6.8%; HR 0.72; 95% CI 0.57-0.90; p = .004) were significantly lower in intravascular modality guidance compared with angiography guidance. The difference was mainly driven by reduced all-cause mortality (4.4 vs. 7.0%; p < .001) and cardiac mortality (3.3 vs. 5.2%; p < .001). CONCLUSION: In this large-scale AMI registry, intravascular modality guidance was associated with an improving clinical outcome in selected high-risk patients.

Relative risk of plaque erosion among different age and sex groups in patients with acute coronary syndrome.

Postmortem studies reported plaque erosion is frequent in young women. Recent in vivo studies failed to show age and sex differences in the plaque erosion prevalence. The aim of this study was to investigate the prevalence of plaque erosion by age and sex among acute coronary syndromes (ACS) patients. From 1699 ACS patients, 1083 with plaque erosion or rupture were analyzed. Patients were categorized as 5 age groups (≤ 50, 51-60, 61-70, 71-80, ≥ 81 years). Overall prevalence of plaque erosion was similar between males and females (p = 0.831). Males age ≤ 50 had higher (p = 0.018) and age 71-80 had lower (p = 0.006) prevalence of plaque erosion. Females age 61-70 had higher (p = 0.021) and age 71-80 had lower (p = 0.045) prevalence of plaque erosion. In advanced age groups (≥ 71 years), rupture was the dominant etiology in both sexes. In multivariate analysis of males, age ≤ 50 demonstrated a trend to increase (OR 1.418, 95% CI 0.961-2.093, p = 0.078) the erosion risk. Females age ≤ 70 independently increased (OR 2.138, 95% CI 1.249-3.661, p = 0.006) the risk for erosion. The prevalence of plaque erosion was similar between males and females. Plaque erosion risk was increased in the males age ≤ 50 and in the females age ≤ 70 among ACS patients.

Prognostic Impact of ß-Blocker Dose After Acute Myocardial Infarction.

BACKGROUND: The differential prognostic impact of ß-blocker dose after acute myocardial infarction (AMI) has been under debate. The current study sought to compare clinical outcome after AMI according to ß-blocker dose using the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH). Methods and Results: Of the total population of 13,104 consecutive AMI patients enrolled in the KAMIR-NIH, the current study analyzed 11,909 patients. These patients were classified into 3 groups (no ß-blocker; low-dose [<25% of target dose]; and high-dose [≥25% of target dose]). The primary outcome was cardiac death at 1 year. Compared with the no ß-blocker group, both the low-dose and high-dose groups had significantly lower risk of cardiac death (HR, 0.435; 95% CI: 0.363-0.521, P<0.001; HR, 0.519; 95% CI: 0.350-0.772, P=0.001, respectively). The risk of cardiac death, however, was similar between the high- and low-dose groups (HR, 1.194; 95% CI: 0.789-1.808, P=0.402). On multivariable adjustment and inverse probability weighted analysis, the result was the same. CONCLUSIONS: The use of ß-blockers in post-AMI patients had significant survival benefit compared with no use of ß-blockers. There was no significant additional benefit of high-dose ß-blockers compared with low-dose ß-blockers, however, in terms of 1-year risk of cardiac death.

Effects of Statin Intensity on Clinical Outcome in Acute Myocardial Infarction Patients.

BACKGROUND: There has been debate regarding the added benefit of high-intensity statins compared with low-moderate-intensity statins, especially in patients with acute myocardial infarction (AMI).Methods and Results:The Korea Acute Myocardial Infarction Registry-National Institutes of Health consecutively enrolled 13,104 AMI patients. Of these, a total of 12,182 patients, who completed 1-year follow-up, were included in this study, and all patients were classified into 3 groups (no statin; low-moderate-intensity statin; and high-intensity statin). The primary outcome was major adverse cardiac event (MACE) including cardiac death, non-fatal MI, and repeat revascularization at 1 year. Both low-moderate-intensity and high-intensity statin significantly reduced low-density lipoprotein cholesterol (LDL-C; all P<0.001). Compared with the no statin group, both statin groups had significantly lower risk of MACE (low-moderate intensity: HR, 0.506; 95% CI: 0.413-0.619, P<0.001; high intensity: HR, 0.464; 95% CI: 0.352-0.611, P<0.001). The risk of MACE, however, was similar between the low-moderate- and high-intensity statin groups (HR, 0.917; 95% CI: 0.760-1.107, P=0.368). Multivariable adjustment, propensity score matching, and inverse probability weighted analysis also produced the same results. CONCLUSIONS: When adequate LDL-C level is achieved, patients on a low-moderate-intensity statin dose have similar cardiovascular outcomes to those on high-intensity statins.

Prevalence and Predictors of Multiple Coronary Plaque Ruptures: In Vivo 3-Vessel Optical Coherence Tomography Imaging Study.

OBJECTIVE: Plaque rupture may be the local expression of a widespread coronary instability. This study aimed to investigate: (1) the prevalence and characteristics of nonculprit plaque rupture; (2) the pancoronary atherosclerotic phenotype in patients with and without nonculprit plaque rupture; and (3) the prevalence and predictors of multiple plaque ruptures. APPROACH AND RESULTS: Six hundred and seventy-five nonculprit plaques from 261 patients (34 acute myocardial infarction, 73 unstable angina pectoris, and 154 stable angina pectoris) were analyzed by 3-vessel optical coherence tomography. Nonculprit plaque ruptures were identified in 51 patients (20%). Patients with nonculprit plaque ruptures had higher prevalence of thin-cap fibroatheroma (51% versus 13%; P<0.001) in the 3 major epicardial coronary vessels. Multiple plaque ruptures were observed in 20% of patients (38% acute myocardial infarction versus 10% unstable angina pectoris versus 19% stable angina pectoris; P=0.042). Thin-cap fibroatheroma, intimal vasculature, and macrophages were independent morphological predictors of multiple plaque ruptures, whereas acute myocardial infarction and chronic kidney disease were independent clinical predictors. Patients with nonculprit plaque ruptures showed higher 1-year rates of nontarget lesion revascularization (11.8% versus 4.4%; P=0.039). CONCLUSIONS: Nonculprit plaque ruptures were observed in 20% of patients with coronary artery disease and were associated with pancoronary vulnerability and higher 1-year revascularization rate.

Multicenter Cohort Study of Acute Myocardial Infarction in Korea　- Interim Analysis of the Korea Acute Myocardial Infarction Registry-National Institutes of Health Registry.

BACKGROUND: The Korea Acute Myocardial Infarction Registry (KAMIR)-National Institutes of Health (NIH) registry has the aim of evaluating the clinical characteristics, management, and long-term outcomes of patients with acute myocardial infarction (AMI) in Korea. METHODS AND RESULTS: Patients hospitalized for AMI in 20 tertiary university hospitals in Korea have been enrolled since November 2011. The study is expected to complete the scheduled enrollment of approximately 13,000 patients in October 2015, and follow-up duration is up to 5 years for each patient. As of October 2015, an interim analysis of 13,623 subjects was performed to understand the baseline clinical profiles of the study population. The mean age was 64.1 years; 73.5% were male; and 48.2% were diagnosed with ST-segment elevation AMI. Hypertension is a leading cause of AMI in Korea (51.2%), followed by smoking (38.5%) and diabetes mellitus (28.6%). Percutaneous coronary intervention was performed in 87.4% and its success rate was very high (99.4%). In-hospital, 1-year, and 2-year mortality rates were 3.9%, 4.3%, and 8.6%, respectively. The rates of major adverse cardiac events at 1 and 2 years were 9.6% and 18.8%, respectively. CONCLUSIONS: This analysis demonstrated the clinical characteristics of Korean AMI patients in comparison with those of other countries. It is necessary to develop guidelines for Asian populations to further improve their prognosis. (Circ J 2016; 80: 1427-1436).

The Prognostic Value of the Left Ventricular Ejection Fraction Is Dependent upon the Severity of Mitral Regurgitation in Patients with Acute Myocardial Infarction.

The prognostic value of the left ventricle ejection fraction (LVEF) after acute myocardial infarction (AMI) has been questioned even though it is an accurate marker of left ventricle (LV) systolic dysfunction. This study aimed to examine the prognostic impact of LVEF in patients with AMI with or without high-grade mitral regurgitation (MR). A total of 15,097 patients with AMI who received echocardiography were registered in the Korean Acute Myocardial Infarction Registry (KAMIR) between January 2005 and July 2011. Patients with low-grade MR (grades 0-2) and high-grade MR (grades 3-4) were divided into the following two sub-groups according to LVEF: LVEF ≤ 40% (n = 2,422 and 197, respectively) and LVEF > 40% (n = 12,252 and 226, respectively). The primary endpoints were major adverse cardiac events (MACE), cardiac death, and all-cause death during the first year after registration. Independent predictors of mortality in the multivariate analysis in AMI patients with low-grade MR were age ≥ 75 yr, Killip class ≥ III, N-terminal pro-B-type natriuretic peptide > 4,000 pg/mL, high-sensitivity C-reactive protein ≥ 2.59 mg/L, LVEF ≤ 40%, estimated glomerular filtration rate (eGFR), and percutaneous coronary intervention (PCI). However, PCI was an independent predictor in AMI patients with high-grade MR. No differences in primary endpoints between AMI patients with high-grade MR (grades 3-4) and EF ≤ 40% or EF > 40% were noted. MR is a predictor of a poor outcome regardless of ejection fraction. LVEF is an inadequate method to evaluate contractile function of the ischemic heart in the face of significant MR.

Characteristics, in-hospital and long-term clinical outcomes of nonagenarian compared with octogenarian acute myocardial infarction patients.

We compared clinical characteristics, management, and clinical outcomes of nonagenarian acute myocardial infarction (AMI) patients (n=270, 92.3 ± 2.3 yr old) with octogenarian AMI patients (n=2,145, 83.5 ± 2.7 yr old) enrolled in Korean AMI Registry (KAMIR). Nonagenarians were less likely to have hypertension, diabetes and less likely to be prescribed with beta-blockers, statins, and glycoprotein IIb/IIIa inhibitors compared with octogenarians. Although percutaneous coronary intervention (PCI) was preferred in octogenarians than nonagenarians, the success rate of PCI between the two groups was comparable. In-hospital mortality, the composite of in-hospital adverse outcomes and one year mortality were higher in nonagenarians than in octogenarians. However, the composite of the one year major adverse cardiac events (MACEs) was comparable between the two groups without differences in MI or re-PCI rate. PCI improved 1-yr mortality (adjusted hazard ratio [HR], 0.50; 95% confidence interval [CI], 0.36-0.69, P<0.001) and MACEs (adjusted HR, 0.47; 95% CI, 0.37-0.61, P<0.001) without significant complications both in nonagenarians and octogenarians. In conclusion, nonagenarians had similar 1-yr MACEs rates despite of higher in-hospital and 1-yr mortality compared with octogenarian AMI patients. PCI in nonagenarian AMI patients was associated to better 1-yr clinical outcomes.

Effect of statin treatment in patients with acute myocardial infarction and left ventricular systolic dysfunction according to the level of high-sensitivity C-reactive protein.

The effects of statins on the prognosis of patients with left ventricular (LV) systolic dysfunction remain controversial. The aim of this study was to assess the effect of statin treatment on clinical outcomes in acute myocardial infarction (AMI) patients with LV systolic dysfunction. A total of 5,119 AMI patients with LV ejection fraction less than 50% on the initial echocardiogram were analyzed in the Korean Acute Myocardial Infarction Registry. The study population was divided into 4 groups according to the level of high sensitivity C-reactive protein (hs-CRP) and statin treatment: low hs-CRP (hs-CRP ≤ 2.0 mg/L) and high hs-CRP (hs-CRP > 2 mg/L) with or without statin therapy. We evaluated the incidence of major adverse cardiac events (MACEs) including cardiac death, reinfarction, target lesion revascularization, and coronary artery bypass grafting during a 12-month period in each group. Statin therapy did not significantly prevent the MACEs in the low hs-CRP groups (with statin: 10.1% versus without statin: 12.0%, P = 0.249). In the high hs-CRP groups, however, the incidence of MACEs was significantly decreased with statin treatment (with statin: 11.3%, without statin: 20.8%, P < 0.001). These findings were consistently observed in all subgroups of the high-hs CRP group, including the subgroup with an LV ejection fraction less than 40%. In a multivariable logistic regression analysis of the high hs-CRP group, lack of statin therapy was a significant predictor of MACE incidence (odds ratio: 1.573, 95% confidence interval: 1.079-2.293, P = 0.018). The statin treatment was associated with better outcome in AMI and LV dysfunction patients with hs-CRP ≥ 2 mg/dL.

Effect of hemoglobin A1c change on 24-month clinical outcomes in patients with diabetes after acute myocardial infarction.

BACKGROUND: The average glycated hemoglobin (HbA1c) may not accurately reflect glycemic control status during the mid-term after acute myocardial infarction (AMI). We aimed to evaluate changes in HbA1c and their effect on mid-term clinical outcomes in patients with diabetes and AMI. METHODS: We enrolled patients with diabetes ( n  = 967) who underwent HbA1c measurement in the Korean nationwide registry. These patients were categorized into three groups based on changes in HbA1c from index admission to the 1-year follow-up visit: a decrease in HbA1c > 1%, changes in HbA1c within 1%, and an increase in HbA1c > 1%. Clinical outcomes at 24 months were examined. RESULTS: The baseline HbA1c levels were 8.55 ±â€…0.85, 7.00 ±â€…0.98 and 7.07 ±â€…1.05 ( P  = 0.001) and HbA1c levels after 1 year were 6.62 ±â€…0.73, 7.05 ±â€…0.98 and 9.26 ±â€…1.59 ( P  = 0.001) for patients with 3 groups, respectively. Patients with a 1% decrease in HbA1c had significantly lower incidence of major adverse cardiovascular events (MACE), cardiac death, and rehospitalization after 24 months than those with a 1% increase in HbA1c. However, in the Cox regression analysis, a >1% decrease in HbA1c change was not an independent factor for MACE, cardiac death, and rehospitalization. CONCLUSIONS: Our analysis indicates that an HbA1c decrease of >1% within the first 12 months was not an independent prognostic factor until the 24-month mark. Therefore, standard diabetic control is recommended for patients with diabetes and AMI for up to 2 years.

The Efficacy and Tolerability of Irbesartan/Amlodipine Combination Therapy in Patients With Essential Hypertension Whose Blood Pressure Were not Controlled by Irbesartan Monotherapy.

PURPOSE: This study aimed to evaluate the efficacy and tolerability of irbesartan (IRB) and amlodipine (AML) combination therapy in patients with essential hypertension whose blood pressure (BP) was not controlled by IRB monotherapy. METHODS: Two multicenter, randomized, double-blind, placebo-controlled, phase III studies were conducted in Korea (the I-DUO 301 study and the I-DUO 302 study). After a 4-week run-in period with either 150 mg IRB (I-DUO 301 study) or 300 mg IRB (I-DUO 302 study), patients with uncontrolled BP (ie, mean sitting systolic BP [MSSBP] ≥140 mmHg to <180 mmHg and mean sitting diastolic BP <110 mmHg) were randomized to the placebo, AML 5 mg, or AML 10 mg group. A total of 428 participants were enrolled in the 2 I-DUO studies. In the I-DUO 301 study, 271 participants were randomized in a 1:1:1 ratio to receive either IRB/AML 150/5 mg, IRB/AML 150/10 mg, or IRB 150 mg/placebo. In the I-DUO 302 study, 157 participants were randomized in a 1:1 ratio to receive IRB/AML 300/5 mg or IRB 300 mg/placebo. The primary endpoint was the change in MSSBP from baseline to week 8. Tolerability was assessed according to the development of treatment-emergent adverse events (TEAEs) and clinically significant changes in physical examination, laboratory tests, pulse, and 12-lead electrocardiography. FINDINGS: In I-DUO 301, the mean (SD) changes of MSSBP at week 8 from baseline were -14.78 (12.35) mmHg, -21.47 (12.78) mmHg, and -8.61 (12.19) mmHg in the IRB/AML 150/5 mg, IRB/AML 150/10 mg, and IRB 150 mg/placebo groups, respectively. In I-DUO 302, the mean (SD) changes of MSSBP at week 8 from baseline were -13.30 (12.47) mmHg and -7.19 (15.37) mmHg in the IRB/AML 300/5 mg and IRB 300 mg/placebo groups, respectively. In both studies, all combination groups showed a significantly higher reduction in MSSBP than the IRB monotherapy groups (P < 0.001 for both). TEAEs occurred in 10.00%, 10.99%, and 12.22% of participants in the IRB/AML 150/5 mg, IRB/AML 150/10 mg, and IRB 150 mg/placebo groups, respectively, in I-DUO 301 and in 6.33% and 10.67% of participants in the IRB/AML 300/5 mg and IRB 300 mg/placebo groups, respectively, in I-DUO 302, with no significant between-group differences. Overall, there was one serious adverse event throughout I-DUO study. IMPLICATIONS: The combination of IRB and AML has superior antihypertensive effects compared with IRB alone over an 8-week treatment period, with placebo-like tolerability. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05476354 (I-DUO 301), NCT05475665 (I-DUO 302).

Comparison of triple anti-platelet therapy and dual anti-platelet therapy in patients with acute myocardial infarction who had no-reflow phenomenon during percutaneous coronary intervention.

BACKGROUND: No-reflow phenomenon is a serious complication of percutaneous coronary intervention (PCI) and associated with poor prognosis. The aim of this study was to determine whether triple anti-platelet therapy could improve clinical outcome in patients with acute myocardial infarction (AMI) who had no-reflow phenomenon during PCI compared with dual anti-platelet therapy. METHODS AND RESULTS: A total of 727 eligible patients received either dual anti-platelet therapy (aspirin and clopidogrel; dual group, n=532) or triple anti-platelet therapy (aspirin, clopidogrel, and cilostazol; triple group, n=195). The triple group received additional cilostazol for at least 1 month. One-year major adverse cardiac events (MACE) including death, myocardial infarction (MI), target vessel revascularization (TVR) and coronary artery bypass graft (CABG) were evaluated. The triple group had a similar incidence of major bleeding and in-hospital mortality compared with the dual group. At 1 year, the triple group had significantly lower cardiac mortality (17.7% vs. 11.8%, log-rank P=0.039), lower all-cause mortality (19.0% vs. 12.3%, log-rank P=0.035), and lower incidence of composite MACE (25.9% vs. 16.9%, adjusted hazard ratio, 0.50; 95% confidence interval: 0.31-0.80, P=0.004) compared with the dual group with no differences in MI and TVR. CONCLUSIONS: Triple anti-platelet therapy seems to be superior to dual anti-platelet therapy in patients with AMI who had no-reflow phenomenon during PCI.

New horizons of acute myocardial infarction: from the Korea Acute Myocardial Infarction Registry.

As the first nationwide Korean prospective multicenter data collection registry, the Korea Acute Myocardial Infarction Registry (KAMIR) launched in November 2005. Through a number of innovative approaches, KAMIR suggested new horizons about acute myocardial infarction (AMI) which contains unique features of Asian patients from baseline characteristics to treatment strategy. Obesity paradox was existed in Korean AMI patients, whereas no gender differences among them. KAMIR score suggested new risk stratifying method with increased convenience and an enhanced accuracy for the prediction of adverse outcomes. Standard loading dose of clopidogrel was enough for Asian AMI patients. Triple antiplatelet therapy with aspirin, clopidogrel and cilostazol could improve clinical outcomes than dual antiplatelet therapy with aspirin and clopidogrel. Statin improved clinical outcomes even in AMI patients with very low LDL-C levels. The rate of percutaneous coronary intervention was higher and door-to-balloon time was shorter than the previous reports. Zotarolimus eluting stents as the 2nd generation drug-eluting stent (DES) was not superior to the 1st generation DES, in contrast to the western AMI studies. KAMIR made a cornerstone in the study of Korean AMI and expected to be new standards of care for AMI with the renewal of KAMIR design to overcome its pitfalls.

Percutaneous coronary intervention for acute myocardial infarction in elderly patients with renal dysfunction: results from the Korea Acute Myocardial Infarction Registry.

This study aimed to evaluate the effects of percutaneous coronary intervention (PCI) on short- and long-term major adverse cardiac events (MACE) in elderly (>75 yr old) acute myocardial infarction (AMI) patients with renal dysfunction. As part of Korea AMI Registry (KAMIR), elderly patients with AMI and renal dysfunction (GFR<60 mL/min) received either medical (n=439) or PCI (n=1,019) therapy. Primary end point was in-hospital death. Secondary end point was MACE during a 1 month and 1 yr follow-up. PCI group showed a significantly lower incidence of in-hospital death (20.0% vs 14.3%, P=0.006). Short-term and long-term MACE rates were higher in medical therapy group (31.9% vs 19.0%; 57.7% vs 31.3%, P<0.001), and this difference was mainly attributed to cardiac death (29.3% vs 17.6%; 51.9% vs 25.0%, P<0.001). MACE-free survival time after adjustment was also higher in PCI group on short-term (hazard ratio, 0.67; confidence interval, 0.45-0.98; P=0.037) and long-term follow-up (hazard ratio, 0.61, confidence interval, 0.45-0.83; P=0.002). In elderly AMI patients with renal dysfunction, PCI therapy yields favorable in-hospital and short-term and long-term MACE-free survival.

Influence of renal dysfunction on clinical outcomes in patients with congestive heart failure complicating acute myocardial infarction.

The clinical course and medical treatment of patients with congestive heart failure (CHF) complicating acute myocardial infarction (AMI) are not well established, especially in patients with concomitant renal dysfunction. We performed a retrospective analysis of the prospective Korean Acute Myocardial Infarction Registry to assess the medical treatments and clinical outcomes of patients with CHF (Killip classes II or III) complicated by AMI, in the presence or absence of renal dysfunction. Of 13,498 patients with AMI, 2769 (20.5%) had CHF on admission. Compared to CHF patients with preserved renal function, in-hospital mortality and major adverse cardiac events were increased both at 1 month and at 1 year after discharge in patients with renal dysfunction (1154; 41.7%). Postdischarge use of aspirin, betablockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers and statins significantly reduced the 1-year mortality rate for CHF patients with renal dysfunction; such reduction was not observed for those without renal dysfunction, except in the case of aspirin. Patients with CHF complicating AMI, which is accompanied by renal dysfunction, are at higher risk for adverse cardiovascular outcomes than patients without renal dysfunction. However, they receive fewer medications proven to reduce mortality rates.

Clinical outcome of unprotected left main coronary artery disease in patients with acute myocardial infarction.

The clinical outcome of patients with acute myocardial infarction (MI) with unprotected left main coronary artery (LMCA) stenosis is not fully understood. We sought to assess the outcomes of patients with acute MI who underwent percutaneous coronary intervention (PCI) for unprotected LMCA stenosis. A total of 587 patients enrolled in the Korea Acute Myocardial Infarction Registry with LMCA stenosis were analyzed. Patients with culprit LMCA had higher inhospital mortality than patients with non-culprit LMCA (16.0% versus 8.9%, P = 0.008), but had similar clinical outcomes during a 12-month follow-up. Compared to CABG, PCI using drug-eluting stents (DES) was more frequently performed with similar early and 12-month clinical outcomes. The efficacy of sirolimus-eluting stents, paclitaxel-eluting stents, and zotarolimus-eluting stents were comparable at 12-month clinical follow-up. Predictors of 12-month mortality included mechanical ventilation, cardiogenic shock, age > 65 years, and ejection fraction < 40%. Patients with acute MI and culprit LMCA have higher early mortality than patients with non-culprit LMCA. PCI with DES is frequently performed and the clinical outcome is similar between the 3 types of first-generation DES.

Prognosis after discontinuing renin angiotensin aldosterone system inhibitor for heart failure with restored ejection fraction after acute myocardial infarction.

Prognostic effect of discontinuing renin-angiotensin-aldosterone-system-inhibitor (RAASi) for patients with heart failure (HF) after acute myocardial infarction (AMI) whose left ventricular (LV) systolic function was restored during follow-up is unknown. To investigate the outcome after discontinuing RAASi in post-AMI HF patients with restored LV ejection fraction (EF). Of 13,104 consecutive patients from the nationwide, multicenter, and prospective Korea Acute Myocardial Infarction-National Institutes of Health (KAMIR-NIH) registry, HF patients with baseline LVEF < 50% that was restored to ≥ 50% at 12-month follow-up were selected. Primary outcome was a composite of all-cause death, spontaneous MI, or rehospitalization for HF at 36-month after index procedure. Of 726 post-AMI HF patients with restored LVEF, 544 maintained RAASi (Maintain-RAASi) beyond 12-month, 108 stopped RAASi (Stop-RAASi), and 74 did not use RAASi (RAASi-Not-Used) at baseline and follow-up. Systemic hemodynamics and cardiac workloads were similar among groups at baseline and during follow-up. Stop-RAASi group showed elevated NT-proBNP than Maintain-RAASi group at 36-month. Stop-RAASi group showed significantly higher risk of primary outcome than Maintain-RAASi group (11.4% vs. 5.4%; adjusted hazard ratio [HRadjust] 2.20, 95% confidence interval [CI] 1.09-4.46, P = 0.028), mainly driven by increased risk of all-cause death. The rate of primary outcome was similar between Stop-RAASi and RAASi-Not-Used group (11.4% vs. 12.1%; HRadjust 1.18 [0.47-2.99], P = 0.725). In post-AMI HF patients with restored LV systolic function, RAASi discontinuation was associated with significantly increased risk of all-cause death, MI, or rehospitalization for HF. Maintaining RAASi will be necessary for post-AMI HF patients, even after LVEF is restored.