Korean Acute Myocardial Infarction Registry Research Articles

Long-term clinical outcomes of image-guided percutaneous coronary intervention in acute myocardial infarction from the Korea Acute Myocardial Infarction Registry.

Imaging modalities for percutaneous coronary intervention (PCI), such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT), have increased in the current PCI era. However, their clinical benefits in acute myocardial infarction (AMI) have not been fully elucidated. This study investigated the long-term outcomes of image-guided PCI in patients with AMI using data from the Korean Acute Myocardial Infarction Registry. A total of 9,271 patients with AMI, who underwent PCI with second-generation drug-eluting stents between November 2011 and December 2015, were retrospectively examined, and target lesion failure (TLF) at 3 years (defined as the composite of cardiac death, target vessel myocardial infarction, and ischemia-driven target lesion revascularization) was evaluated. From the registry, 2,134 patients (23.0%) underwent image-guided PCI (IVUS-guided: n = 1,919 [20.6%]; OCT-guided: n = 215 patients [2.3%]). Based on propensity score matching, image-guided PCI was associated with a significant reduction in TLF (hazard ratio: 0.76; 95% confidence interval: 0.59-0.98, p = 0.035). In addition, the TLF incidence in the OCT-guided PCI group was comparable to that in the IVUS-guided PCI group (5.3% vs 4.7%, p = 0.903). Image-guided PCI, including IVUS and OCT, is associated with favorable clinical outcomes in patients with AMI at 3 years post-intervention. Additionally, OCT-guided PCI is not inferior to IVUS-guided PCI in patients with AMI.

Acute myocardial infarction prognosis prediction with reliable and interpretable artificial intelligence system.

Predicting mortality after acute myocardial infarction (AMI) is crucial for timely prescription and treatment of AMI patients, but there are no appropriate AI systems for clinicians. Our primary goal is to develop a reliable and interpretable AI system and provide some valuable insights regarding short, and long-term mortality. We propose the RIAS framework, an end-to-end framework that is designed with reliability and interpretability at its core and automatically optimizes the given model. Using RIAS, clinicians get accurate and reliable predictions which can be used as likelihood, with global and local explanations, and "what if" scenarios to achieve desired outcomes as well. We apply RIAS to AMI prognosis prediction data which comes from the Korean Acute Myocardial Infarction Registry. We compared FT-Transformer with XGBoost and MLP and found that FT-Transformer has superiority in sensitivity and comparable performance in AUROC and F1 score to XGBoost. Furthermore, RIAS reveals the significance of statin-based medications, beta-blockers, and age on mortality regardless of time period. Lastly, we showcase reliable and interpretable results of RIAS with local explanations and counterfactual examples for several realistic scenarios. RIAS addresses the "black-box" issue in AI by providing both global and local explanations based on SHAP values and reliable predictions, interpretable as actual likelihoods. The system's "what if" counterfactual explanations enable clinicians to simulate patient-specific scenarios under various conditions, enhancing its practical utility. The proposed framework provides reliable and interpretable predictions along with counterfactual examples.

Changes of hospital-level variation in use of optimal medical treatment for long-term follow-up from a multi-level methodological approach

Abstract Background Contemporary guidelines documented that optimal medical therapy (OMT) should be prescribed to improve clinical outcome in patients with acute myocardial infarction (AMI). However, the changes of hospital-level variations in prescription rates of OMT for long-term follow-up are unknown. Purpose We aimed to investigate (1) impact of hospital-level variation on the use of each medication and OMT and (2) changes of hospital-level variation in prescription rates of individual medical therapy and OMT during the follow-up. Methods We examined hospital medications of 13,516 AMI patients without documented contraindications to antiplatelet agents, β-blockers (BB), angiotensin-converting enzyme inhibitors (ACE) /angiotensin II receptor blockers (ARB), or statins from the Korean Acute Myocardial Infarction Registry (KAMIR) – National Institute of Health (NIH) database. OMT was defined as use of all 4 indicated medications. Hierarchical generalized linear mixed models estimated hospital-level variation in prescription rates of OMT and each medication after adjustment for patient-level factors. Variation was explored with a median rate ratio (MRR), which estimates the relative difference in risk ratios of 2 hypothetically identical patients at 2 different hospitals. Results The prescription rates of OMT and each effective cardiac medications are presented in Figure. There were substantial decreases in the prescription rates for OMT (from 66.7% to 51.6%) and dual antiplatelet agents (from 99.1% to 50.4%) for 2 years follow-up. After adjustment for patient-level covariates, hospital-level MRR for OMT was 1.47 at discharge, indicating an 47% likelihood that 2 random hospitals would differ in treating identical AMI patients. As the prescription rates of OMT and each effective cardiac medications decreased, adjusted hospital-level MRR for OMT (from 1.47 to 1.22), BB therapy (from 1.35 to 1.15), ACE/ARB therapy (from 1.68 to 1.16), and statin therapy (from 1.19 to 1.06) decreased for 2-year follow-up, whereas MRR for dual antiplatelet therapy increased at 1 year (MRR; 1.61) and 2 years (MRR; 1.63) follow-up (Figure). Among patient-level factors, age >70 years, Killip class>2, obesity, hypertension, previous coronary artery disease, renal dysfunction, reduced ejection fraction, percutaneous coronary intervention was independently associated with the use of OMT. Conclusion Hospital-level variations in the use of OMT and each effective cardiac medications were observed at discharge, but weakened overtime, except for use of dual antiplatelet therapy.

Abstract 16866: Complete Revascularization for Left Main Acute Myocardial Infarction

Background: In patients presenting with acute myocardial infarction (AMI) with left main (LM) culprit lesion and multivessel disease, percutaneous coronary intervention (PCI) of non-culprit lesions in LM culprit AMI is challenging and whether it reduces mortality and adverse events is unclear. Hypothesis: Complete revascularization will show better outcome than culprit-only revascularization in multi-vessel LM AMI PCI. Methods: We reviewed total of 16831 patients among from July 2016 to June 2020 Korean Acute Myocardial Infarction Registry (KAMIR) and 395 patients were enrolled with LM culprit multi-vessel AMI treated by PCI. We excluded in-hospital death 35 cases then categorized patients whether treated with complete revascularization (n=198) or culprit-only revascularization (n=162). Study outcome was a composite of major cardiac adverse events (MACE) including cardiac death, myocardial infarction, re-PCI, stent thrombosis and rehospitalization due to heart failure. We used propensity score (PS) matching method and cumulative event-free survival and MACE were analyzed over 3 years follow-up. Results: After PS matching, baseline and angiographic characteristics were similar between two groups (Complete group, n=142 versus Culprit-only group, n=142). Killip classification (Class IV : n=13 (9.2%) versus n=14 (9.9%), p -value=0.762) and initial diagnosis (STEMI : n=47 (33.1%) versus n=52 (36.6%), p- value=0.618) at admission were also not different between two groups. There was no difference in MACE between two groups (n=27 (19%) versus n=28 (19.7%), log-rank test p- value = 0.64). Conclusion: Although, other studies had shown better outcome of complete revascularization in multi-vessel AMI, in multi-vessel LM AMI PCI, complete revascularization should be carefully decided depending on the patient's condition.

Clinical Outcomes of Calcium-Channel Blocker vs Beta-Blocker: From the Korean Acute Myocardial Infarction Registry

BackgroundAlthough current guidelines recommend beta-blockers (BBs) after acute myocardial infarction (AMI), the role of calcium-channel blockers (CCBs) has not been well investigated, especially nondihydropyridine. ObjectivesThis study aimed to compare the effects of CCBs on cardiovascular outcomes compared with BBs in AMI because patients from East Asia have a higher incidence of a vasospastic angina component compared with Western countries. MethodsAmong 15,628 patients enrolled in the KAMIR-V (Korean Acute Myocardial Infarction Registry-V), we evaluated 10,650 in-hospital survivors who were treated with either CCBs or BBs. We applied a propensity score for 1:4 pair matching of baseline covariates and Cox regression to compare CCBs and BBs. The primary endpoint was all-cause death at 1 year. The secondary endpoints were 1-year major adverse cardiac and cerebrovascular events, which was the composite of cardiac death, myocardial infarction, revascularization, and readmission due to heart failure and stroke. ResultsThere was a significant interaction with the treatment arm with left ventricular ejection fraction (LVEF) (P for interaction = 0.011). CCB groups at discharge had higher 1-year cardiac death and major adverse cardiac and cerebrovascular events for patients with LVEF <50% (HR: 4.950; 95% CI: 1.329-18.435; P = 0.017; and HR: 1.810; 95% CI: 1.038-3.158; P = 0.037, respectively) but not for patients with LVEF ≥50% (HR: 0.699; 95% CI: 0.435-1.124; P = 0.140). ConclusionsCCB therapy did not increase adverse cardiovascular events for patients after AMI with preserved LVEF. CCBs can be considered as an alternative for BBs in East Asian patients after AMI with preserved LVEF.

The Impact of Pulmonary Hypertension on the Clinical Outcomes of Acute Myocardial Infarction after Percutaneous Coronary Intervention

Background/Aims: Pulmonary hypertension (PH) in patients with heart failure contributes to a poor prognosis. However, the role of PH in the long-term clinical outcome is unclear in those with acute myocardial infarction (AMI). The clinical significance of elevated right ventricular systolic pressure (RVSP) on routine echocardiography is underestimated.Methods: This study enrolled 2,526 AMI patients (65.1 ± 12.7 years; 1,757 males [69.6%]) from the Korean AMI registry who underwent successful percutaneous coronary intervention and pre-discharge transthoracic echocardiography (TTE). The patients were divided into four groups according to the RVSP on TTE: normal RVSP (RVSP &lt; 35 mmHg, n = 1,695), mild PH (35 ≤ RVSP &lt; 45 mmHg, n = 601), moderate PH (45 ≤ RVSP &lt; 70 mmHg, n = 211), and severe PH (RVSP ≥ 70 mmHg, n = 19). Major adverse cardiac events (MACE) were compared among the four groups.Results: During the 3-year clinical follow-up period, MACE occurred in 562 patients (22.2%), including 321 (18.9%), 145 (24.1%), 83 (39.3%), and 13 patients (68.4%) in the normal RVSP and mild, moderate, and severe PH groups, respectively. On multivariate analysis, independent factors for MACE were moderate or severe PH, age ≥ 65 years, Killip class ≥ III, left ventricular ejection fraction &lt; 40%, hypertension, and diabetes.Conclusions: Measuring RVSP is useful for stratifying the risk of patients with AMI; MACE occurred in patients with moderate or severe PH.

Association between baseline smoking status and clinical outcomes following myocardial infarction.

BackgroundWhether the effect of smoking on clinical outcomes following an acute myocardial infarction (AMI) is beneficial or detrimental remains inconclusive. We invesetigated the effect of smoking on the clinical outcomes in patients following an AMI.MethodsAmong 13,104 patients between November 2011 and June 2015 from a nationwide Korean AMI registry, a total of 10,193 participants were extracted then classified into two groups according to their smoking habit: (1) smoking group (n = 6,261) and (2) non-smoking group (n = 3,932). The participants who smoked were further subclassified according to their smoking intensity quantified by pack years (PYs): (1) <20 PYs (n = 1,695); (2) 20–40 PYs (n = 3,018); and (3) ≥40 PYs (n = 2,048). Each group was compared to each other according to treatment outcomes. The primary outcome was the incidence of major adverse cardiac and cerebrovascular events (MACCEs), which is a composite of all-cause mortality, non-fatal MI (NFMI), any revascularization, cerebrovascular accident, rehospitalization, and stent thrombosis. Secondary outcomes included the individual components of MACCEs. The Cox proportional hazard regression method was used to evaluate associations between baseline smoking and clinical outcomes following an AMI. Two propensity score weighting methods were performed to adjust for confounders, including propensity score matching and inverse probability of treatment weighting.ResultsWhile the incidence of all clinical outcomes, except for stent thrombosis, was lower in the smoking group than in the non-smoking group in the unadjusted data, the covariates-adjusted data showed statistical attenuation of these differences but a higher all-cause mortality in the smoking group. For smokers, the incidence of MACCEs, all-cause mortality, cardiac and non-cardiac death, and rehospitalization was significantly different between the groups, with the highest rates of MACCE, all-cause mortality, non-cardiac death, and rehospitalization in the group with the highest smoking intensity. These differences were statistically attenuated in the covariates-adjusted data, except for MACCEs, all-cause mortality, and non-cardiac death, which had the highest incidence in the group with ≥40 PYs.ConclusionSmoking had no beneficial effect on the clinical outcomes following an AMI. Moreover, for those who smoked, clinical outcomes tended to deteriorate as smoking intensity increased.

Derivation and validation of a combined in-hospital mortality and bleeding risk model in acute myocardial infarction.

In the potent new antiplatelet era, it is important issue how to balance the ischemic risk and the bleeding risk. However, previous risk models have been developed separately for in-hospital mortality and major bleeding risk. Therefore, we aimed to develop and validate a novel combined model to predict the combined risk of in-hospital mortality and major bleeding at the same time for initial decision making in patients with acute myocardial infarction (AMI). Variables from the Korean Acute Myocardial Infarction Registry (KAMIR) - National Institute of Health (NIH) database were used to derive (n=8955) and validate (n=3838) a multivariate logistic regression model. Major adverse cardiovascular events (MACEs) were defined as in-hospital death and major bleeding. Seven factors were associated with MACE in the model: age, Killip class, systolic blood pressure, heart rate, serum glucose, glomerular filtration rate, and initial diagnosis. The risk model discriminated well in the derivation (c-static=0.80) and validation (c-static=0.80) cohorts. The KAMIR-NIH risk score was developed from the model and corresponded well with observed MACEs: very low risk (0.9%), low risk (1.7%), moderate risk (4.2%), high risk (8.6%), and very high risk (23.3%). In patients with MACEs, a KAMIR-NIH risk score≤10 was associated with high bleeding risk, whereas a KAMIR-NIH risk score>10 was associated with high in-hospital mortality. The KAMIR-NIH in-hospital MACEs model using baseline variables stratifies comprehensive risk for in-hospital mortality and major bleeding, and is useful for guiding initial decision making.

Prognostic value of novel neutrophil-to-hemoglobin and lymphocyte score in patients with acute myocardial infarction

We developed and assessed whether a novel neutrophil-to-hemoglobin and lymphocyte (NHL) score would improve the ability to predict clinical outcome compared with neutrophil-to-lymphocyte ratio (NLR) and systemic immune-inflammation index (SII) in acute myocardial infarction (AMI). We examined 13,072 AMI patients from the Korean AMI Registry–National Institute of Health database. NHL score was calculated as follows: NHL score (U) = N/(Hb × L), where N, Hb, and L are baseline blood neutrophil, hemoglobin, and lymphocyte count. The primary outcome was the occurrence of major adverse cerebrocardiovascular events (MACCEs) at 2 years. The NLR, SII, and NHL score were independent predictors of 2-year MACCEs. The area under the curve of the NHL score (0.637) for predicting 2-year MACCEs was significantly higher compared with those of SII (0.589) and NLR (0.607). The NHL score significantly improved the reclassification and integrated discrimination compared with NLR ( p &lt; 0.0001) and SII ( p &lt; 0.0001). A high NHL score (≥ 0.35 U) was an independent predictor of 2-year MACCEs (adjusted hazard ratio, 1.41; 95% confidence interval, 1.29–1.55; p &lt; 0.001). The NHL score could be a novel model for predicting long-term MACCEs in patients with AMI.

Variation in treatment strategy for non-ST segment elevation myocardial infarction: A multilevel methodological approach

BackgroundVariations by hospital and region in the selection of an early invasive strategy (EIS) after non–ST-segment elevation myocardial infarction (NSTEMI) in patients with high-risk criteria are unknown. MethodsWe evaluated the data of 7037 patients with NSTEMI from 20 hospitals of 3 regions from the Korean Acute Myocardial Infarction Registry–National Institute of Health database. We used hierarchical generalized linear mixed-models to estimate region- and hospital-level variation in the selection of an EIS after adjusting for patient-level high-risk criteria. We explored the variation using the median rate ratio (MRR), which estimates the relative difference in the risk ratios of two hypothetically identical patients at two different sites. ResultsAn EIS was selected in 84.4% of patients. At the hospital level, the median selection rate was 80.4%. At the region level, the median selection rate was 74.9% in the east region, 81.3% in the north region, and 83.9% in the west region, respectively. After adjusting for patient-level covariates, we found significant hospital- (MRR 2.19, 95% confidence interval [CI]: 1.74–3.03) and region-level (MRR 1.88, 95%CI: 1.26–5.44) variation in the selection of an EIS. Among patient-level factors, male sex, ongoing chest pain, history of coronary artery disease or acute heart failure, and GRACE risk score > 140 were independently associated with the selection of an EIS. ConclusionsWe observed significant hospital- and region-level variation in the selection of an EIS after NSTEMI in high-risk patients. Quality improvement efforts are required to standardize decision making and to improve clinical outcomes.

Long-term efficacy of vasodilating β-blocker in patients with acute myocardial infarction: nationwide multicenter prospective registry

Background/AimsLong-term benefit of vasodilating β-blockers is unknown. This study aimed to investigate the long-term benefit of vasodilating β-blockers over conventional β-blockers in patients with acute myocardial infarction (AMI).MethodsUsing nationwide prospective multicenter Korean Acute Myocardial Infarction Registry data, we analyzed 3-year clinical outcomes of 7,269 patients with AMI who received percutaneous coronary intervention (PCI) and β-blocker therapy. Patients were classified according to treatment strategy (vasodilating β-blockers vs. conventional β-blockers). The primary endpoint was a composite of cardiac death, myocardial infarction (MI), and hospitalization for heart failure (HF) at 3 years. Secondary outcomes were each component of the primary outcome. Propensity score matching was performed to adjust for differences of baseline characteristics.ResultsIn 3,079 pairs (6,158 patients) of propensity score-matched patients, the primary outcome occurred significantly less in the vasodilating β-blockers group compared with the conventional β-blockers group (7.6% vs. 9.8%, p = 0.003). Among the secondary outcomes, cardiac death occurred significantly less in the vasodilating β-blockers group than in the conventional group (3.5% vs. 4.8%, p = 0.015). The incidence rates of MI (2.4% vs. 3.0%, p = 0.160) or hospitalization for HF (2.6% vs. 3.2%, p = 0.192) were not significantly different between the two groups.ConclusionsVasodilating β-blocker therapy was associated with better clinical outcomes compared with conventional β-blocker therapy in AMI patients undergoing PCI during 3 years follow-up. Vasodilating β-blockers could be recommended preferentially for these patients.

P3583Optimal procedural strategy to improve clinical outcome in primary percutaneous coronary intervention

Abstract Background Current guideline recommends potent antiplatelet agents and transradial intervention. However, it is uncertain whether routine use of IVUS, thrombus aspiration and glycoprotein IIB-IIIA inhibitor is beneficial for improving clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI). Purpose The aim of this study was to investigate optimal procedural strategy to improve clinical outcome. Methods A total of 6,046 patients who underwent primary percutaneous coronary intervention (PCI) for STEMI were analyzed from the Korean Acute Myocardial Infarction Registry (KAMIR) – National Institute of Health (NIH) database. MACCEs were defined as a composition of all cause death, non-fatal MI, repeat revascularizations including repeated percutaneous coronary intervention and coronary bypass grafting, cerebrovascular accident and rehospitalizations. This research was supported by a fund by Research of Korea Centers for Disease Control and Prevention. Results During the primary PCI, potent antiplatelet agents such as prasugrel and ticagrelor were used in 2342 (38.4%). PCI was performed through transradial approach in 1490 (25.2%). Thrombus aspiration and intravascular ultrasound (IVUS) examination was done in 2204 (36.1%) and 1079 (18.1%), respectively. Glycoprotein IIB-IIIA inhibitor was administered in 1295 (21.7%). Among them, potent antiplatelet agents, transradial intervention, IVUS, and thrombus aspiration significantly reduced MACCEs at 1 year. Glycoprotein IIB-IIIA inhibitor was not effective to improved clinical outcome. In Cox-proportional hazards model, potent antiplatelet agents (hazard ratio 0.82, 95% confidence interval 0.67–0.99; p=0.045) and transradial intervention (hazard ratio 0.61, 95% confidence interval 0.47–0.78; p&lt;0.001) was an independent predictor of MACCEs after adjusting for confounding variables. Combined use of potent antiplatelet agents and transradial intervention (hazard ratio 0.54; 95% confidence interval 0.37–0.80; p=0.002) substantially reduced MACCEs at 1 year. Conclusion Among evidence based procedures during the primary PCI, combined use of potent antiplatelet agents and transradial intervention was optimal procedural strategy to improve clinical outcome.

Usefulness of Calculation of Cardiovascular Risk Factors to Predict Outcomes in Patients With Acute Myocardial Infarction

Cardiovascular risk factors contribute differently to short-term prognosis of acute myocardial infarction (AMI); hypertension and diabetes increase adverse outcomes, whereas hyperlipidemia, smoking, and obesity seem to paradoxically decrease these in post-MI patients. We aimed to investigate whether a simple calculation of conventional risk factors, PARADOCS (Pressure of ARtery elevAtion, Diabetes, Obesity, Cholesterol, Smoking) score, would improve the ability to predict major adverse cardiac and cerebrovascular events (MACCEs) in post-MI patients. Between November 2011 and December 2015, 13,104 patients with diagnosis of AMI were analyzed in this study from Korean AMI Registry - National Institute of Health database. PARADOCS score was calculated as follows: (number of nonparadoxical risk factors - number of paradoxical risk factors) + 3 where nonparadoxical risk factors are hypertension and diabetes, and paradoxical risk factors are hyperlipidemia, smoking, and obesity. PARADOCS score was significantly greater in patients with 1-year MACCEs compared with those without MACCEs (3.43 ± 1.03 vs 2.88 ± 1.11, p <0.001). In Cox proportional hazards model, PARADOCS score was an independent predictor of 1-year MACCEs (hazards ratio 1.23, 95% confidence interval 1.16 to 1.30; p <0.001) after adjusting for confounding variables. In Kaplan-Meier survival curve, patients with greater PARADOCS score had worse clinical outcome. In conclusion, although it needs more validation, a simple calculation of risk factors, PARADOCS score, could provide useful prognostic information of MI patients to clinicians.

Radial Versus Femoral Access With or Without Vascular Closure Device in Patients With Acute Myocardial Infarction

Compared with transradial intervention (TRI), it is unclear whether transfemoral intervention (TFI) with vascular closure device (VCD) improves major adverse cardiocerebrovascular events (MACCE) in patients with acute myocardial infarction (AMI). The aim of this study is to compare TRI versus TFI with or without VCD for reducing MACCEs. We examined 11,596 patients who underwent TRI or TFI from the Korean AMI Registry - National Institute of Health database. The MACCE at 1-year was defined as death, nonfatal MI, repeat revascularization, cerebrovascular accident, hospitalizations, and major bleedings. Because the patients were not randomly assigned to vascular access sites, propensity-score (PS) matching was performed. In the PS-matched cohorts, compared with TFI, TRI significantly reduced 1-year MACCEs (7.1% vs 10.1%; log-rank p < 0.001) through a reduction in major bleeding (0.6% vs 2.2%; p < 0.001). Compared with TRI, 1-year MACCEs (11.3% vs 7.9%, log-rank p < 0.001) and major bleedings (0.6% vs 2.2%; p < 0.001) were significantly greater in TFI without VCD, whereas TFI with VCD was comparable in 1-year MACCEs (7.5% vs 8.1%, log-rank p = 0.437) and major bleeding (0.7% vs 1.0%; p = 0.409). In conclusion, the use of VCD could be an alternative to avoid major bleeding and to improve clinical outcomes, particularly in high-risk patients who are not suitable for TRI.

Third-Generation P2Y12 Inhibitors in East Asian Acute Myocardial Infarction Patients: A Nationwide Prospective Multicentre Study.

Third-generation P2Y12 inhibitors (prasugrel, ticagrelor) are recommended in acute myocardial infarction (AMI). We aimed to evaluate the efficacy and safety of third-generation P2Y12 inhibitors in East Asian AMI patients. From the Korean AMI Registry, 9,355 patients who received dual antiplatelet agent (aspirin with clopidogrel [AC], 6,444 [70.5%] patients; aspirin with prasugrel [AP], 1,100 [11.8%] patients; or aspirin with ticagrelor [AT], 1,811 [19.4%] patients) were analysed. In-hospital endpoints were all-cause mortality or bleeding events during admission and 1-year endpoints were major adverse cardiac and cerebrovascular events (MACCE) and major bleeding events. Regarding in-hospital events, AP and AT showed similar all-cause mortality rates but higher bleeding event rates compared with AC. This trend was extended to 1-year endpoints; Cox regression analysis showed that third-generation P2Y12 inhibitors had significantly higher bleeding risk (AP vs. AC: hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.53-2.99; p < 0.001; AT vs. AC: HR, 2.26; 95% CI, 1.73-2.95; p < 0.001). A propensity score matched triplet of 572 patients showed similar 1-year MACCE and higher bleeding events with third-generation P2Y12 inhibitors (2.1 vs. 2.6 vs. 2.1%, p = 0.790 for MACCE and 3.1 vs. 8.0 vs. 8.0%, p < 0.001 for bleeding events, in AC, AP and AT groups, respectively). Inverse probability weighted regression analysis and pooled analysis after randomly imputing missing variables showed consistent results. Collectively, prasugrel and ticagrelor showed similar rates of 1-year MACCE, but a higher rate of bleeding events, compared with clopidogrel in Korean AMI patients. Further studies are warranted to adapt Western guidelines on third-generation P2Y12 inhibitors for East Asians.

Effects of Bisoprolol Are Comparable with Carvedilol in Secondary Prevention of Acute Myocardial Infarction in Patients Undergoing Percutaneous Coronary Intervention.

Although the benefits of carvedilol have been demonstrated in the era of percutaneous coronary intervention (PCI), very few studies have evaluated the efficacy of bisoprolol in the secondary prevention of acute myocardial infarction (MI) in patients treated with PCI. We hypothesized that the effect of bisoprolol would not be different from carvedilol in post-MI patients. A total of 13,813 patients who underwent PCI were treated either with carvedilol or bisoprolol at the time of discharge. They were enrolled from the Korean Acute MI Registry (KAMIR). After 1:2 propensity score matching, 1,806 patients were enrolled in the bisoprolol group and 3,612 patients in the carvedilol group. The primary end point was the composite of major adverse cardiac events (MACEs), which was defined as cardiac death, nonfatal MI, target vessel revascularization, and coronary artery bypass surgery. The secondary end point was defined as all-cause mortality, cardiac death, nonfatal MI, any revascularization, or target vessel revascularization. After adjustment for differences in baseline characteristics by propensity score matching, the MACE-free survival rate was not different between the groups (HR=0.815, 95% CI:0.614–1.081, p=0.156). In the subgroup analysis, the cumulative incidence of MACEs was lower in the bisoprolol group in patients having a Killip class of III or IV than in the carvedilol group (HR=0.512, 95% CI: 0.263–0.998, p=0.049). The incidence of secondary end points was similar between the two beta-blocker groups. In conclusion, the benefits of bisoprolol were comparable with those of carvedilol in the secondary prevention of acute MI.

Benefits of Statin Therapy in Patients With Acute Myocardial Infarction With Serum Low-Density Lipoprotein Cholesterol ≤ 50 mg/dl

Previous trials have found that statin therapy reduces low-density lipoprotein cholesterol (LDL-C) level and the risk of cardiovascular events. However, the benefit of statin therapy in patients with baseline LDL-C levels ≤ 50mg/dl is less clear. Therefore, the aim of this study was to assess whether patients with acute myocardial infarction (AMI) who have baseline LDL-C levels ≤ 50mg/dl would benefit from statin therapy in real-world clinical practice. We analyzed the clinical data of 1,048 patients (67.3 ± 12.6years, 69.6% men) with AMI, who had baseline LDL-C levels ≤ 50mg/dl from the Korean Acute Myocardial Infarction Registry data between November 2005 and May 2014. They were divided into 2 groups based on whether they were prescribed statins or not at discharge (statin and nonstatin group, n= 738 and 310, respectively). The primary end point was the major adverse cardiac event (MACE), defined as the composite of all-cause mortality, recurrent myocardial infarction, and repeated percutaneous coronary intervention or coronary artery bypass grafting. MACE occurred in 9.2% of the statin group versus 19.6% in the nonstatin group during the 12-month follow-up. Statin therapy significantly reduced the risk of MACE (hazard ratio [HR] 0.60, 95% CI 0.39 to 0.94, p= 0.025) and coronary artery bypass grafting (HR 0.27, 95% CI 0.08 to 0.96, p= 0.043). There was a trend of reduced cardiac death in the statin group compared with the nonstatin group (HR 0.52, 95% CI 0.26 to 1.02, p= 0.059). Statin therapy for patients with AMI with LDL-C levels ≤ 50mg/dl was associated with improved outcomes. Therefore, statin therapy is feasible and effective, even in AMI patients with extremely low levels of LDL-C.

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.

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.

The scientific achievements of the decades in Korean Acute Myocardial Infarction Registry.

The Korea Acute Myocardial Infarction Registry (KAMIR) was the first nationwide registry data collection designed to track outcomes of patients with acute myocardial infarction (AMI). These studies reflect the current therapeutic approaches and management for AMI in Korea. The results of KAMIR could help clinicians to predict the prognosis of their patients and identify better diagnostic and treatment tools to improve the quality of care. The KAMIR score was proposed to be a predictor of the prognosis of AMI patients. Triple antiplatelet therapy, consisting of aspirin, clopidogrel and cilostazol, was effective at preventing major adverse clinical outcomes. Drug-eluting stents were effective and safe in AMI patients with no increased risk of stent thrombosis. Statin therapy was effective in Korean AMI patients, including those with very low levels of low density cholesterol. The present review summarizes the 10-year scientific achievements of KAMIR from admission to outpatient care during long-term clinical follow-up.