Korea Acute Myocardial Infarction Research Articles

Optimal timing of revascularization for patients with non-ST segment elevation myocardial infarction and severe left ventricular dysfunction.

Optimal timing of revascularization for patients who presented with non-ST segment elevation myocardial infarction (NSTEMI) and severe left ventricular (LV) dysfunction is unclear. A total of 386 NSTEMI patients with severe LV dysfunction from the nationwide, multicenter, and prospective Korea Acute Myocardial Infarction Registry V (KAMIR-V) were enrolled. Severe LV dysfunction was defined as LV ejection fraction ≤ 35%. Patients with cardiogenic shock were excluded. Patients were stratified into two groups: PCI within 24 hours (early invasive group) and PCI over 24 hours (selective invasive group). Primary endpoint was major adverse cardiac and cerebrovascular events (MACCE) including all-cause death, non-fatal MI, repeat revascularization, and stroke at 12 months after index procedure. Early invasive group showed higher incidence of in-hospital death (9.4% vs 3.3%, P = .036) and cardiogenic shock (11.5% vs 4.6%, P = .030) after PCI. Early invasive group also showed higher maximum troponin I level during admission (27.7 ± 44.8 ng/mL vs 14.9 ± 24.6 ng/mL, P = .001), compared with the selective invasive group. Early invasive group had an increased risk of 12-month MACCE, compared with selective invasive group (25.6% vs 17.1%; adjusted HR = 2.10, 95% CI 1.17-3.77, P = .006). Among NSTEMI patients with severe LV dysfunction, the early invasive strategy did not improve the clinical outcomes. This data supports that an individualized approach may benefit high-risk NSTEMI patients rather than a routine invasive approach.

Prognostic Implications of N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Non-ST-Elevation Myocardial Infarction.

Limited data exist regarding the prognostic implications of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with non-ST-elevation myocardial infarction (NSTEMI) who undergo percutaneous coronary intervention (PCI). Of 13,104 patients in the nationwide Korea Acute Myocardial Infarction Registry-National Institutes of Health, 3,083 patients with NSTEMI who underwent PCI were included in the present study. The primary endpoint was major adverse cardiovascular events (MACE) at 3 years, a composite of all-cause death, recurrent myocardial infarction, unplanned repeat revascularization, and admission for heart failure. NT-proBNP was measured at the time of initial presentation for the management of NSTEMI, and patients were divided into a low (<700 pg/mL; n=1,813) and high (≥700 pg/mL; n=1,270) NT-proBNP group. The high NT-proBNP group had a significantly higher risk of MACE, driven primarily by a higher risk of cardiac death or admission for heart failure. These results were consistent after confounder adjustment by propensity score matching and inverse probability weighting analysis. In patients with NSTEMI who underwent PCI, an initial elevated NT-proBNP concentration was associated with higher risk of MACE at 3 years, driven primarily by higher risks of cardiac death or admission for heart failure. These results suggest that the initial NT-proBNP concentration may have a clinically significant prognostic value in NSTEMI patients undergoing PCI.

Beyond β-Blockade: ACE Inhibitors Reduce Non-Cardiac Mortality in High Killip Grade AMI Patients.

This study evaluates the 3-year clinical outcomes of high Killip grade (III/IV) acute myocardial infarction (AMI) patients treated with either β-blockers (BB) and angiotensin-converting enzyme inhibitors (ACEI) or BB and angiotensin receptor blockers (ARB). A total of 13,105 patients were registered at the Korea Acute Myocardial Infarction Registry at the National Institute of Health (KAMIR-NIH). Among them, 871 patients with high Killip classification AMI were divided into the BB + ACEI group (n = 489) and the BB + ARB group (n = 381). Following propensity score matching, 343 patients were selected in each group. All patients completed a 3-year follow-up period. The results indicate no significant differences between the BB + ACEI group and BB + ARB group in terms of cardiac death, recurrent myocardial infarction, and the rate of repeat percutaneous coronary intervention. However, the BB + ACEI group exhibited significantly lower risks in major adverse cardiac events (HR = 0.574, 95% CI: 0.421-0.783, p < .001), all-cause mortality (HR = 0.561, 95% CI: 0.404-0.778, p = .001), and non-cardiac death (HR = 0.365, 95% CI: 0.208-0.639, p < .001) compared to the BB + ARB group. Our results suggest that BB + ACEI treatment is more beneficial than BB + ARB for high Killip grade AMI patients. Additionally, the BB + ACEI group has a superior preventative effect on mortality compared to the BB + ARB group.

Very early vs delayed invasive strategy in high-risk NSTEMI patients without hemodynamic instability: Insight from the KAMIR-NIH

Background High-risk non-ST-elevation myocardial infarction (NSTEMI) patients’ optimal timing for percutaneous coronary intervention (PCI) is debated despite the recommendation for early invasive revascularization. This study aimed to compare outcomes of NSTEMI patients without hemodynamic instability undergoing very early invasive strategy (VEIS, ≤ 12 hours) versus delayed invasive strategy (DIS, &gt;12 hours). Methods Excluding urgent indications for PCI including initial systolic blood pressure under 90 mmHg, ventricular arrhythmia, or Killip class IV, 4,733 NSTEMI patients were recruited from the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH). Patients were divided into low and high- global registry of acute coronary events risk score risk score (GRS) groups based on 140. Both groups were then categorized into VEIS and DIS. Clinical outcomes, including all-cause death (ACD), cardiac death (CD), recurrent MI, and cerebrovascular accident at 12 months, were evaluated. Results Among 4,733 NSTEMI patients, 62% had low GRS, and 38% had high GRS. The proportions of VEIS and DIS were 43% vs. 57% in the low GRS group and 47% vs. 53% in the high GRS group. In the low GRS group, VEIS and DIS demonstrated similar outcomes; however, in the high GRS group, VEIS exhibited worse ACD outcomes compared to DIS (HR = 1.46, P = 0.003). The adverse effect of VEIS was consistent with propensity score matched analysis (HR = 1.34, P = 0.042). Conclusion VEIS yielded worse outcomes than DIS in high-risk NSTEMI patients without hemodynamic instability in real-world practice.

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.

A cost-sensitive deep neural network-based prediction model for the mortality in acute myocardial infarction patients with hypertension on imbalanced data.

Hypertension is one of the most serious risk factors and the leading cause of mortality in patients with cardiovascular diseases (CVDs). It is necessary to accurately predict the mortality of patients suffering from CVDs with hypertension. Therefore, this paper proposes a novel cost-sensitive deep neural network (CSDNN)-based mortality prediction model for out-of-hospital acute myocardial infarction (AMI) patients with hypertension on imbalanced data. The synopsis of our research is as follows. First, the experimental data is extracted from the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH) and preprocessed with several approaches. Then the imbalanced experimental dataset is divided into training data (80%) and test data (20%). After that, we design the proposed CSDNN-based mortality prediction model, which can solve the skewed class distribution between the majority and minority classes in the training data. The threshold moving technique is also employed to enhance the performance of the proposed model. Finally, we evaluate the performance of the proposed model using the test data and compare it with other commonly used machine learning (ML) and data sampling-based ensemble models. Moreover, the hyperparameters of all models are optimized through random search strategies with a 5-fold cross-validation approach. In the result, the proposed CSDNN model with the threshold moving technique yielded the best results on imbalanced data. Additionally, our proposed model outperformed the best ML model and the classic data sampling-based ensemble model with an AUC of 2.58% and 2.55% improvement, respectively. It aids in decision-making and offers a precise mortality prediction for AMI patients with hypertension.

Association between body mass index and three-year outcome of acute myocardial infarction

Body mass index (BMI), as an important risk factor related to metabolic disease. However, in some studies higher BMI was emphasized as a beneficial factor in the clinical course of patients after acute myocardial infarction (AMI) in a concept known as the “BMI paradox.” The purpose of this study was to investigate how clinical outcomes of patients treated for AMI differed according to BMI levels. A total of 10,566 patients in the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH) from May 2010 to June 2015 were divided into three BMI groups (group 1: BMI < 22 kg/m2, group 2: ≥ 22 and < 26 kg/m2, and group 3: ≥ 26 kg/m2). The primary outcome was major adverse cardiac and cerebrovascular event (MACCE) at 3 years of follow-up. At 1 year of follow-up, the incidence of MACCE in group 1 was 10.1% of that in group 3, with a hazard ratio (HR) of 2.27, and 6.5% in group 2, with an HR of 1.415. This tendency continued up to 3 years of follow-up. The study demonstrated that lower incidence of MACCE in the high BMI group of Asians during the 3-year follow-up period compared to the low BMI group. The results implied higher BMI could exert a positive effect on the long-term clinical outcomes of patients with AMI undergoing percutaneous coronary intervention (PCI).

Long-term air pollution exposure is associated with higher incidence of ST-elevation myocardial infarction and in-hospital cardiogenic shock

Previous studies have reported the association between myocardial infarction (MI) and air pollution (AP). However, limited information is available regarding the long-term effects of AP on the relative incidence rates of ST-elevation MI (STEMI) and Non-ST-elevation MI (NSTEMI). We investigated the association between long-term exposure to AP and the incidence of STEMI. Between January 2006 and December 2015, a total of 45,619 eligible patients with Acute Myocardial Infarction (AMI) were enrolled in the Korea Acute MI Registry (KAMIR) and KAMIR-National Institutes of Health. Mixed-effect regression models were used to examine the association between the annual average ambient AP before MI onset and the incidence of STEMI, and to evaluate the association of AP with the incidence of in-hospital cardiogenic shock. After mixed-effect regression model analysis, particulate matter (PM) 10 µm or less in diameter (PM10) was associated with increased incidence of STEMI compared with NSTEMI (odds ratio [OR] 1.009, 95% Confidence Interval [CI] 1.002–1.016; p = 0.012). For in-hospital cardiogenic shock complication, PM10 and SO2 were associated with increased risk, PM10 (OR 1.033, 95% CI 1.018–1.050; p < 0.001), SO2 (OR 1.104, 95% CI 1.006–1.212; p = 0.037), respectively. Policy-level strategies and clinical efforts to reduce AP exposure are necessary to prevent the incidence of STEMI and severe cardiovascular complications.

Impact of multivessel versus single-vessel disease on the association between low diastolic blood pressure and mortality after acute myocardial infarction with revascularization.

Previous studies demonstrated a J-shaped relationship between low diastolic blood pressure (DBP) and adverse clinical outcomes in patients with acute myocardial infarction (AMI) that was sensitive to revascularization. Hypothesized herein, was that this relationship differs between patients with multivessel disease (MVD) and those with single-vessel disease due to differing degrees of myocardial ischemic burden. Among 9,983 AMI patients from the Korea Acute Myocardial Infarction Registry database who underwent percutaneous coronary intervention and were followed up for a median duration of 3.2 years, average on-treatment DBP was calculated at admission, discharge, and every scheduled visit and divided into these parameters: < 70 mmHg, 70-74 mmHg, 75-79 mmHg, and ≥ 80 mmHg. The relationship between average on-treatment DBP and clinical outcomes including all-cause death, cardiovascular (CV) death, non-CV death, and hospitalization for heart failure was analyzed using the Cox regression models adjusted for clinical covariates. In patients with MVD, all-cause death (hazard ratio [HR]: 1.47; 95% confidence interval [CI]: 1.06-2.04, p = 0.012) and CV death (HR: 1.59; 95% CI: 1.02-2.46, p = 0.027) were significantly increased in patients with a DBP < 70 mmHg, showing a J-shaped relationship. However, these findings were not significant for single-vessel disease. On a sensitivity analysis excluding subjects with a baseline SBP < 120 mmHg, an increased risk of a low DBP < 70 mmHg remained in MVD. The J-shaped relationship between low DBP and adverse clinical outcomes in AMI patients who underwent revascularization persisted in MVD, which has a high ischemic burden. These high-risk patients require cautious treatment.

Incidence and case fatality of acute myocardial infarction in Korea, 2011-2020.

Cardiovascular diseases are a leading cause of mortality worldwide, and acute myocardial infarction (AMI) is particularly fatal condition. We evaluated the incidence and case fatality rates of AMI in Korea from 2011 to 2020. We utilized data from the National Health Insurance Services to calculate crude, age-standardized, and age-specific incidence rates, along with 30-day and 1-year case fatality rates, of AMI from 2011 to 2020. Age-standardized incidence rates were determined using direct standardization to the 2005 population. The crude incidence rate of AMI per 100,000 person-years consistently increased from 44.7 in 2011 to 68.3 in 2019, before decreasing slightly to 66.2 in 2020. The age-standardized incidence rate of AMI displayed a 19% rise from 2011 to 2019, followed by a slight decline in 2020. The increasing trend for AMI incidence was more pronounced in males than in females. Both 30-day and 1-year case fatality rates remained stable among younger individuals but showed a decrease among older individuals. There was a minor surge in case fatality in 2020, particularly among recurrent AMI cases. Over the past decade, the AMI incidence rate in Korea has consistently increased, with a slight downturn in 2020. The case fatality rate has remained relatively stable except for a minor increase in 2020. This study provides data for continuous surveillance, the implementation of targeted interventions, and the advancement of research aimed at AMI in Korea.

Adherence to guideline-directed medical therapy and 3-year clinical outcome following acute myocardial infarction

Abstract Aims Despite the well-established clinical benefits and strong recommendations in clinical guidelines, adherence to guideline-directed medical therapy (GDMT) is known to be insufficient. We investigated the adherence to GDMT and its impact on the 3-year clinical outcomes in patients with acute myocardial infarction (AMI). Methods and results Source data were obtained from KAMIR-NIH, a Korean multicenter observational registry. GDMT was defined according to the ACC/AHA class I recommendations. Adherence to GDMT was assessed at discharge and every year thereafter. The differences in clinical characteristics between patients receiving and those not receiving GDMT were adjusted using propensity score matching (PSM) or inverse probability of treatment weighting (IPTW). The primary endpoint was major adverse cardiovascular events (MACE), which was a composite of all-cause death and non-fatal MACE, including MI, revascularization, or stroke. Of 12,815 patients, GDMT adherence was 70.2% at discharge, and decreased gradually into 54.6% at 3-year. GDMT at discharge was associated with lower MACE risk in the unadjusted analysis (HR=0.51, 95%CI=0.47–0.55, p&amp;lt;0.001) and also in the PSM- or IPTW-adjusted analyses (HR=0.77, 95%CI=0.69–0.86; HR=0.79, 95%CI=0.72–0.86; p&amp;lt;0.001, all). These findings were replicated in the 1-year or 2-year landmark analyses (HR=0.58 to 0.82, p&amp;lt;0.01, all). Conclusion Adherence to GDMT was suboptimal among patients with AMI in Korea. As the adherence to GDMT was associated with a lower incidence of MACE during 3-year follow-up, the maintenance of long-term GDMT might be crucial for patients with AMI.Structured Graphical Abstract

Abstract 15254: Temporal Assessment of Clinical Outcomes in Patients With ST-Elevation Myocardial Infarction and Non-ST-Elevation Myocardial Infarction

Background: Limited data exist regarding the temporal progression of outcomes in patients with ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI). Research Questions: Are there any significant differences in the occurrence of cardiovascular events over time between patients with STEMI and NSTEMI in the modern era of percutaneous coronary intervention? Aims: We aimed to compare the incidence rates of major cardiovascular events over time between patients with STEMI and NSTEMI using the Korea Acute Myocardial Infarction Registry-National Institutes of Health database. Methods: We analysed the data of 13,056 patients diagnosed with STEMI or NSTEMI between 2011 and 2015 (median age, 65 years [interquartile range {IQR}, 54-74]). We calculated yearly, monthly, weekly, and daily time-point event rates after admission, considering the number of events during the specific periods divided by the number of event-free patients just before those periods. The primary outcome measure was all-cause mortality. Results: During the 3-year follow-up (median, 1095 [IQR, 1044-1095] days), 12.4% of patients (1589/12,836) died from any cause. Patients with STEMI had a significantly higher mortality rate in the first week of admission than that of patients with NSTEMI (4.54% [283/6235] vs 1.76% [120/6823], P &lt; 0.001), but this difference was not observed in the second week (0.59% [35/5952] vs 0.67% [45/6703], P = 0.635). Subsequently, higher mortality rates were observed in patients with NSTEMI than in those with STEMI for all time points. Daily outcome analysis revealed a gradual decrease in the difference in mortality rates in patients with STEMI versus NSTEMI from the first to the ninth day, followed by an inversion on the tenth day: STEMI: 2.39% (149/6235) vs NSTEMI: 0.59% (40/6823) on the first day; 0.13% (8/5942) vs 0.10% (7/6694) on the ninth day; and 0.03% (2/5934) vs 0.13% (9/6687) on the tenth day. Conclusions: This analysis of temporal outcomes from a nationwide Korean registry demonstrated that patients with STEMI initially had higher mortality than patients with NSTEMI, but this difference gradually decreased and subsequently inverted during the second week, specifically after the ninth day.

Beta-blocker therapy in patients with acute myocardial infarction: not all patients need it.

Most of the evidences for beneficial effects of beta-blockers in patients with acute myocardial infarction (AMI) were from the clinical studies published in the pre-reperfusion era when anti-platelet drugs, statins or inhibitors of renin-angiotensin-aldosterone system which are known to reduce cardiovascular mortality of patients with AMI were not introduced. In the reperfusion era, beta-blockers' benefit has not been clearly shown except in patients with reduced ejection fraction (EF; ≤40%). In the era of the early reperfusion therapy for AMI, a number of patients with mildly reduced EF (>40%, <50%) or preserved EF (≥50%) become increasing. However, because no randomized clinical trials are available until now, the benefit and the optimal duration of oral treatment with beta-blockers in patients with mildly reduced or preserved EF are questionable. Registry data have not showed the association of oral beta-blocker therapy with decreased mortality in survivors without heart failure or left ventricular systolic dysfunction after AMI. In the Korea Acute Myocardial Infarction Registry-National Institute of Health of in-hospital survivors after AMI, the benefit of beta-blocker therapy at discharge was shown in patients with reduced or mildly reduced EF, but not in those with preserved EF, which provides new information about beta-blocker therapy in patients without reduced EF. However, clinical practice can be changed when the results of appropriate randomized clinical trials are available. Ongoing clinical trials may help to answer the unresolved issues of beta-blocker therapy in patients with AMI.

Impact of sex difference on clinical outcomes in acute myocardial infarction patients with single-vessel and multi-vessel disease: based on Korea Acute Myocardial Infarction Registry-National Institute of Health.

Several studies have compared clinical outcomes according to sex in patients with acute myocardial infarction (AMI). However, studies evaluating sex differences in clinical outcomes of single-vessel disease (SVD) and multi-vessel disease (MVD) in Korean patients with AMI are lacking. Therefore, this study aimed to analyze sex differences in the clinical characteristics of patients with AMI with SVD and MVD and to evaluate the impact of sex differences on the clinical outcomes in patients with AMI with SVD and MVD. A total of 11,002 AMI patients from November 2011 to June 2015 in the Korea AMI Registry, National Institute of Health, were enrolled. The current study was retrospective observational study. Patients were divided into SVD (n=5,644) and MVD (n=5,358) groups, and clinical impact of sex difference were analyzed by propensity score matching analysis and Cox proportional hazard regression model. Women were older and had poor baseline clinical characteristics than men. Propensity score-matched analysis of men and women with SVD and MVD revealed that the adjusted 3-year risk of major adverse cardiac event (MACE) (15.0% vs. 9.4%; hazard ratio, 1.86; 95% confidence interval, 1.10-3.13; P=0.020) was higher in women with SVD aged <65 years. However, the incidence and risk of MACE were similar for men and women with MVD, and those with SVD aged ≥65 years. In the present study of Korean patients with AMI, women were older and exhibited a higher prevalence of comorbidities than men. Women with SVD aged <65 years had a significantly higher risk of MACE.

Comparison for Use of Telmisartan and Candesartan on 3-Year Clinical Outcomes After Acute Myocardial Infarction in Korean Population: From the Korea Acute Myocardial Infarction Registry-National Institutes of Health

Comparison for Use of Telmisartan and Candesartan on 3-Year Clinical Outcomes After Acute Myocardial Infarction in Korean Population: From the Korea Acute Myocardial Infarction Registry-National Institutes of Health

Incidence, Relevant Patient Factors, and Clinical Outcomes of the Misdiagnosis of ST-Segment-Elevation Myocardial Infarction: Results From the Korea Acute Myocardial Infarction Registry.

Background Data on the incidence, relevant patient factors, and clinical outcomes of the misdiagnosis of ST-segment-elevation myocardial infarction (STEMI) in the modern era of percutaneous coronary intervention are limited. Methods and Results Data from KAMIR (Korea Acute Myocardial Infarction Registry) between November 2011 and June 2020 were analyzed. Out of 28 470 patients with acute myocardial infarction, 11 796 were eventually diagnosed with STEMI following a coronary angiogram. They were classified into 2 groups: patients with an initial working diagnosis of STEMI before starting the initial treatment and patients with an initial working diagnosis of non-STEMI (misdiagnosed group). Out of 11 796 patients with a final diagnosis of STEMI, 165 (1.4%) were misdiagnosed. The door-to-angiography time in the misdiagnosed group was 5 times longer than that in the timely diagnosed group (median 220 [interquartile range {IQR}, 66-1177] versus 43 [IQR, 31-58] minutes; P<0.001). In a multivariable adjustments model, patients with a history of heart failure, atypical chest pain, anemia, or symptom-to-door time ≥4 hours had significantly higher odds, whereas those with systolic blood pressure <100 mm Hg or anterior ST elevation or left bundle-branch block on ECG had lower odds of STEMI misdiagnosis. For patients with culprit lesions in the left anterior descending artery (n=5838), the adjusted 1-year mortality risk for STEMI misdiagnosis was 1.84 (95% CI, 1.01-3.38). Conclusions Misdiagnosis of STEMI is not rare and is associated with a significant delay in coronary angiography, resulting in increased 1-year mortality for patients with culprit lesions in the left anterior descending artery.

Effects of delayed hospitalization on the 3-year clinical outcomes of patients with or without diabetes who had non-ST-segment-elevation myocardial infarction and underwent new-generation drug-eluting stent implantation.

Clinical outcomes after non-ST-segment-elevation myocardial infarction (NSTEMI) in patients with (symptom-to-door time [SDT] ≥ 24 h) or without (SDT < 24 h) delayed hospitalization among patients with or without diabetes were compared. From the Korea Acute Myocardial Infarction Registry-National Institute of Health, a total of 4517 patients with NSTEMI who underwent new-generation drug-eluting stents implantation were recruited and they were classified into the diabetes mellitus (DM) and non-DM groups. These two groups were subdivided into groups with and without delayed hospitalization. The primary clinical outcome was the occurrence of major adverse cardiac and cerebrovascular events (MACCE), defined as all-cause death, recurrent myocardial infarction, repeat coronary revascularization, and stroke. The secondary clinical outcome was the occurrence of individual components of MACCE and stent thrombosis. Although after multivariable and propensity score-adjusted analyses in the DM group, the primary and secondary clinical outcomes between the SDT < 24 h and SDT ≥ 24 h groups were similar; in the non-DM group, all-cause (p = 0.003 and p = 0.007, respectively) and cardiac (p = 0.001 and p = 0.008, respectively) death rates were significantly higher in the SDT ≥ 24 h group than in the SDT < 24 h group. Our results suggested that there was no significant difference in prognosis between diabetic patients with and without delayed SDT, but delayed SDT was associated with poor prognosis in nondiabetic patients.

Adherence to guideline-directed medical therapy and 3-year clinical outcome following acute myocardial infarction.

Despite the well-established clinical benefits and strong recommendations in clinical guidelines, adherence to guideline-directed medical therapy (GDMT) is known to be insufficient. We investigated the adherence to GDMT and its impact on the 3-year clinical outcomes in patients with acute myocardial infarction (AMI). Source data were obtained from KAMIR-NIH, a Korean multi-centre observational registry. GDMT was defined according to the ACC/AHA Class I recommendations. Adherence to GDMT was assessed at discharge and every year thereafter. The differences in clinical characteristics between patients receiving and those not receiving GDMT were adjusted using propensity score matching (PSM) or inverse probability of treatment weighting (IPTW). The primary endpoint was major adverse cardiovascular events (MACE), which was a composite of all-cause death and non-fatal MACE, including myocardial infarction (MI), revascularization, or stroke. Of 12 815 patients, GDMT adherence was 70.2% at discharge, and decreased gradually into 54.6% at 3-year. GDMT at discharge was associated with lower MACE risk in the unadjusted analysis [hazard ratio (HR) = 0.51, 95% confidence intervals (CI) = 0.47-0.55, P < 0.001] and also in the PSM- or IPTW-adjusted analyses (HR = 0.77, 95% CI = 0.69-0.86; HR = 0.79, 95% CI = 0.72-0.86; P < 0.001, all). These findings were replicated in the 1-year or 2-year landmark analyses (HR = 0.58 to 0.82, P < 0.01, all). Adherence to GDMT was sub-optimal among patients with AMI in Korea. As the adherence to GDMT was associated with a lower incidence of MACE during 3-year follow-up, the maintenance of long-term GDMT might be crucial for patients with AMI.

Institutional Variance in Mortality after Percutaneous Coronary Intervention for Acute Myocardial Infarction in Korea, Japan, and Taiwan.

Although there have been studies that compared outcomes of patients with acute myocardial infarction (AMI) across countries, little focus has been placed on institutional variance of outcomes. The aim of the present study was to compare institutional variance in mortality following percutaneous coronary intervention (PCI) for AMI and factors explaining this variance across different health systems. Data on inpatients who underwent PCI for AMI in 2016 were obtained from the National Health Insurance Data Sharing Service in Korea, the Diagnosis Procedure Combination (DPC) Study Group Database in Japan, and the National Health Insurance Research Database (NHIRD) in Taiwan. Multilevel analyses with inpatient mortality as the outcome and the hierarchical structure of patients nested within hospitals were conducted, adjusting for common patient-level and hospital-level variables. We compared the intraclass correlation coefficient (ICC) and the proportion of variance explained by hospital-level characteristics across the three health systems. There were 17 351 patients from 160 Korean hospitals, 29 804 patients from 660 Japanese hospitals, and 10 863 patients from 104 Taiwanese hospitals included in the analysis. Inpatient mortality rates were 6.3%, 7.3%, and 6.0% in Korea, Japan, and Taiwan, respectively. After adjusting for patient and hospital characteristics, Taiwan had the lowest variation in mortality (ICC, 1.8%), followed by Korea (2.2%) and then Japan (4.5%). The measured hospital characteristics explained 38%, 19%, and 9% of the institutional variance in Korea, Taiwan, and Japan, respectively. Korea, Japan, and Taiwan had similarly uniform outcomes across hospitals for patients undergoing PCI for AMI. However, Japan had a relatively large institutional variance in mortality and a lower proportion of variation explainable by hospital characteristics, compared with Korea and Taiwan.

Long-term use of clopidogrel versus ticagrelor or prasugrel in patients with acute myocardial infarction after percutaneous coronary intervention.

To compare the long-term clinical outcomes of dual antiplatelet therapy (DAPT) with clopidogrel and DAPT with ticagrelor or prasugrel in patients with acute myocardial infarction (AMI) who underwent coronary intervention. Between November 2011 and December 2015, a total of 13,104 patients with AMI were enrolled in the Korea Acute Myocardial Infarction Registry-National Institutes of Health (KAMIR-NIH) registry. Among them, 4,696 patients who received DAPT for more than 24 months were categorized into two groups: the clopidogrel group (n = 4,053) and ticagrelor or prasugrel group (n = 643). Propensity score matching (PSM) was used to reduce the bias due to confounding variables. Following PSM, the impacts of P2Y12 inhibitors on the clinical outcomes in both groups were compared during a 36-month clinical follow-up period. There were no significant differences in clinical outcomes in terms of cardiac death (7.1% vs. 9.7%, p = 0.101), stroke (1.4% vs. 1.0%, p = 0.436), major bleeding (0.5% vs. 0.8%, p = 0.478), major adverse cardiac events (MACE) (21.6% vs. 20.5%, p = 0.626), and net adverse cardiac event (NACE) (22.1% vs. 21.3%, p = 0.731) between the groups. The ticagrelor or prasugrel group had a lower incidence of recurrent percutaneous coronary intervention (PCI) (12.2% vs. 7.6%, p = 0.006) than the clopidogrel group. However, no differences were observed in the cumulative incidences of 3-year NACE between the ticagrelor or prasugrel and clopidogrel groups. Cumulative incidences of long-term NACE did not differ between the two groups. Therefore, the type and duration of DAPT should be customized for each patient with AMI.