OBJECTIVES: The escalating burden of cardiovascular disease (CVD) is a critical public health issue worldwide. CVD, especially acute myocardial infarction (AMI) and stroke, is the leading contributor to morbidity and mortality in Korea. We aimed to develop algorithms for identifying AMI and stroke events from the National Health Insurance Service (NHIS) database and validate these algorithms through medical record review. METHODS: We first established a concept and definition of “hospitalization episode,” taking into account the unique features of health claims-based NHIS database. We then developed first and recurrent event identification algorithms, separately for AMI and stroke, to determine whether each hospitalization episode represents a true incident case of AMI or stroke. Finally, we assessed our algorithms’ accuracy by calculating their positive predictive values (PPVs) based on medical records of algorithm- identified events. RESULTS: We developed identification algorithms for both AMI and stroke. To validate them, we conducted retrospective review of medical records for 3,140 algorithm-identified events (1,399 AMI and 1,741 stroke events) across 24 hospitals throughout Korea. The overall PPVs for the first and recurrent AMI events were around 92% and 78%, respectively, while those for the first and recurrent stroke events were around 88% and 81%, respectively. CONCLUSIONS We successfully developed algorithms for identifying AMI and stroke events. The algorithms demonstrated high accuracy, with PPVs of approximately 90% for first events and 80% for recurrent events. These findings indicate that our algorithms hold promise as an instrumental tool for the consistent and reliable production of national CVD statistics in Korea.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS 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.

Background: Fractional flow reserve (FFR) based on computed tomography (CT) has been shown to better identify ischemia-causing coronary stenosis. However, this current technology requires high computational power, which inhibits its widespread implementation in clinical practice. This prospective, multicenter study aimed at validating the diagnostic performance of a novel simple CT based fractional flow reserve (CT-FFR) calculation method in patients with coronary artery disease. Methods: Patients who underwent coronary CT angiography (CCTA) within 90 days and invasive coronary angiography (ICA) were prospectively enrolled. A hemodynamically significant lesion was defined as an FFR ≤ 0.80, and the area under the receiver operating characteristic curve (AUC) was the primary measure. After the planned analysis for the initial algorithm A, we performed another set of exploratory analyses for an improved algorithm B. Results: Of 184 patients who agreed to participate in the study, 151 were finally analyzed.Hemodynamically significant lesions were observed in 79 patients (52.3%). The AUC was 0.71 (95% confidence interval [CI], 0.63–0.80) for CCTA, 0.65 (95% CI, 0.56–0.74) for CT-FFR algorithm A (P = 0.866), and 0.78 (95% CI, 0.70–0.86) for algorithm B (P = 0.112). Diagnostic accuracy was 0.63 (0.55–0.71) for CCTA alone, 0.66 (0.58–0.74) for algorithm A, and 0.76 (0.68–0.82) for algorithm B. Conclusion This study suggests the feasibility of automated CT-FFR, which can be performed on-site within several hours. However, the diagnostic performance of the current algorithm does not meet the a priori criteria for superiority. Future research is required to improve the accuracy.

Background: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. Methods: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. Results: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI;additionally, age (65–74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. Conclusions Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

Background and Objectives: Despite remarkable reduction in cardiovascular disease (CVD) mortality, the burden has remained the leading cause of death. Since little research has focused on regional disparity in CVD mortality, this study aims to investigate its spatiotemporal trends in Korea from 1983 to 2019. Methods: Using the causes of death statistics in Korea, we analyzed the geographic variation in deaths from CVDs from 1983 to 2019. The sex and age-standardized mortality rate was calculated according to the 17 administrative regions. The analyses include all diseases of the circulatory system (International Classification of Diseases-10 codes, I00–I99), along with the following 6 subcategories which were not mutually exclusive: total heart disease (I00–I13 and I20–I51), hypertensive heart disease (I10–I13), ischemic heart disease (I20–I25), myocardial infarction (I21–I23), heart failure (I50), and cerebrovascular disease (I60–I69). Results: Overall, heart failure death rate increased across all regions, and other CVD death rates showed a decreasing trend. Regional disparity in mortality was substantial in the early 1980s but converged over time. In all types of cardiovascular mortality, Busan, Ulsan and Gyeongnam remained the highest, although they showed a downward trend like other regions. Jeju continued to have a relatively low CVD mortality rate. Conclusions The regional disparity substantially decreased compared to the 1980s. However, the relatively high burden of CVD mortality in the southeastern region has not been fully resolved.

Background and Objectives: The aim of this study was to demonstrate the efficacy and safety of treatment with drug-coated balloon (DCB) in a large real-world population. Methods: Patients treated with DCBs were included in a multicenter observational registry that enrolled patients from 18 hospitals in Korea between January 2009 and December 2017. The primary outcome was target lesion failure (TLF) defined as a composite of cardiovascular death, target vessel myocardial infarction, and clinically indicated target lesion revascularization at 12 months. Results: The study included 2,509 patients with 2,666 DCB-treated coronary artery lesions (1,688 [63.3%] with in-stent restenosis [ISR] lesions vs. 978 [36.7%] with de novo lesions).The mean age with standard deviation was 65.7±11.3 years; 65.7% of the patients were men.At 12 months, the primary outcome, TLF, occurred in 179 (6.7%), 151 (8.9%), 28 (2.9%) patients among the total, ISR, and de novo lesion populations, respectively. A history of hypertension, diabetes, acute coronary syndrome, previous coronary artery bypass graft, reduced left ventricular ejection fraction, B2C lesion and ISR lesion were independent predictors of 12 months TLF in the overall study population. Conclusions This large multicenter DCB registry study revealed the favorable clinical outcome of DCB treatment in real-world practice in patient with ISR lesion as well as small de novo coronary lesion.

Purpose: The coronavirus disease 2019 (COVID-19) pandemic disrupted the emergency medical care system worldwide. We analyzed the changes in the management of intracerebral hemorrhage (ICH) and compared the pre-COVID-19 and COVID-19 eras. Materials and Methods: From March to October of the COVID-19 era (2020), 83 consecutive patients with ICH were admitted to four comprehensive stroke centers. We retrospectively reviewed the data of patients and compared the treatment workflow metrics, treatment modalities, and clinical outcomes with the patients admitted during the same period of pre-COVID-19 era (2017–2019). Results: Three hundred thirty-eight patients (83 in COVID-19 era and 255 in pre-COVID-19 era) were included in this study. Symptom onset/detection-to-door time [COVID-19; 56.0 min (34.0–106.0), pre-COVID-19; 40.0 min (27.0–98.0), p=0.016] and median door to-intensive treatment time differed between the two groups [COVID-19; 349.0 min (177.0–560.0), pre-COVID-19; 184.0 min (134.0–271.0), p<0.001]. Hematoma expansion was detected more significantly in the COVID-19 era (39.8% vs. 22.1%, p=0.002). At 3-month follow-up, clinical outcomes of patients were worse in the COVID-19 era (Good modified Rankin Scale; 33.7% in COVID-19, 46.7% in pre-COVID-19, p=0.039). Conclusion During the COVID-19 era, delays in management of ICH was associated with hematoma expansion and worse outcomes.

Purpose: The coronavirus disease 2019 (COVID-19) pandemic disrupted the emergency medical care system worldwide. We analyzed the changes in the management of intracerebral hemorrhage (ICH) and compared the pre-COVID-19 and COVID-19 eras. Materials and Methods: From March to October of the COVID-19 era (2020), 83 consecutive patients with ICH were admitted to four comprehensive stroke centers. We retrospectively reviewed the data of patients and compared the treatment workflow metrics, treatment modalities, and clinical outcomes with the patients admitted during the same period of pre-COVID-19 era (2017–2019). Results: Three hundred thirty-eight patients (83 in COVID-19 era and 255 in pre-COVID-19 era) were included in this study. Symptom onset/detection-to-door time [COVID-19; 56.0 min (34.0–106.0), pre-COVID-19; 40.0 min (27.0–98.0), p=0.016] and median door to-intensive treatment time differed between the two groups [COVID-19; 349.0 min (177.0–560.0), pre-COVID-19; 184.0 min (134.0–271.0), p<0.001]. Hematoma expansion was detected more significantly in the COVID-19 era (39.8% vs. 22.1%, p=0.002). At 3-month follow-up, clinical outcomes of patients were worse in the COVID-19 era (Good modified Rankin Scale; 33.7% in COVID-19, 46.7% in pre-COVID-19, p=0.039). Conclusion During the COVID-19 era, delays in management of ICH was associated with hematoma expansion and worse outcomes.

Background and Objectives: The EPIC™ stent is a self-expanding, nitinol stent that has been designed to enhance flexibility and provide expansion within vessels. The aim of the present study was to investigate the clinical efficacy and safety of the EPIC™ stent when used to treat iliac artery diseases in a prospective Korean multicenter registry. Methods: A total of 138 patients with iliac artery diseases who received endovascular treatment with EPIC™ stents at 9 Korean sites were enrolled in a prospective cohort and followed for 1 year. The primary endpoint was the 1-year freedom from target lesion revascularization (TLR). The secondary endpoints were 1-year clinical patency and freedom from major adverse events (MAEs). Results: The mean age of the study subjects was 66.8±8.5 years and most subjects were male (86.2%). The most frequent lesion type was Trans-Atlantic Inter-Society Consensus B (43.5%) and the majority (56.5%) of the target lesions were located in the common iliac artery. Procedural success was obtained in 99.3% of patients. The freedom from TLR and the clinical patency at 1-year follow-up were 94.9% and 92.3%, respectively. The 1-year rate of MAEs was 5.1%. Combined coronary artery disease (hazard ratio [HR], 5.91; 95% confidence interval [CI], 1.13–30.89; p=0.035) and smaller stent diameter (HR, 0.38; 95% CI, 0.17–0.88;p=0.023) were identified as independent risk factors of TLR after EPIC™ stent implantation. Conclusions The EPIC™ stents demonstrated excellent immediate and 1-year efficacy and safety outcomes in iliac artery lesions in this multicenter, prospective, registry-based study.

Background and Objectives: The EPIC™ stent is a self-expanding, nitinol stent that has been designed to enhance flexibility and provide expansion within vessels. The aim of the present study was to investigate the clinical efficacy and safety of the EPIC™ stent when used to treat iliac artery diseases in a prospective Korean multicenter registry. Methods: A total of 138 patients with iliac artery diseases who received endovascular treatment with EPIC™ stents at 9 Korean sites were enrolled in a prospective cohort and followed for 1 year. The primary endpoint was the 1-year freedom from target lesion revascularization (TLR). The secondary endpoints were 1-year clinical patency and freedom from major adverse events (MAEs). Results: The mean age of the study subjects was 66.8±8.5 years and most subjects were male (86.2%). The most frequent lesion type was Trans-Atlantic Inter-Society Consensus B (43.5%) and the majority (56.5%) of the target lesions were located in the common iliac artery. Procedural success was obtained in 99.3% of patients. The freedom from TLR and the clinical patency at 1-year follow-up were 94.9% and 92.3%, respectively. The 1-year rate of MAEs was 5.1%. Combined coronary artery disease (hazard ratio [HR], 5.91; 95% confidence interval [CI], 1.13–30.89; p=0.035) and smaller stent diameter (HR, 0.38; 95% CI, 0.17–0.88;p=0.023) were identified as independent risk factors of TLR after EPIC™ stent implantation. Conclusions The EPIC™ stents demonstrated excellent immediate and 1-year efficacy and safety outcomes in iliac artery lesions in this multicenter, prospective, registry-based study.