Min Kim

Khil J, et al. Korean Circ J. 2027 ;57:e40. https://doi.org/10.4070/kcj.2026.0060

Kim M, et al. Korean Circ J. 2025 Dec;56:e23. https://doi.org/10.4070/kcj.2025.0242

Kim M. Korean Circ J. 2025 May;55:e94. https://doi.org/10.4070/kcj.2025.0129

Background: With ongoing climate change, the duration of sunshine hours will likely increase over the coming decades that escalating air temperature. Little is known about the potential cardiovascular risk from this climate factor. Purpose: The aim of this study was to test whether duration of sunlight exposure is associated with incident sudden cardiac arrest (SCA), coronary heart disease (CHD), and hospitalization for heart failure (HF) and whether this association depends on seasonal variation. Methods: A total of 308,851 participants from UK Biobank were included and were followed for a median time of 11.8 years. Participants reported how many hours they respectively spent the daylight outdoors on summer and winter typical days. Extreme outliers (>12 hours/day in summer and >8 hours/day in winter) were excluded. Average exposure time was calculated to unify the daylight outdoors time standard. Duration of sunlight exposure (average, summer, and winter) were categorized using quantiles and a restricted cubic spline for outcomes. Multivariate cox proportional hazard regression adjusted by age, sex, demographics, lifestyle, clinical and environmental factors was used for the analysis. Results: During a follow-up, 1,572 (0.51%), 11,557 (3.74%) and 2,145 (0.68%) participants were diagnosed with SCA, CHD and hospitalization for HF. Compared with the participants exposed to short-time sunlight (average ≤ 1.5 hours/day), those who exposed to long-term sunlight (average ≥ 3.5 hours/day) had increased risk of SCA (HR 1.22, 95% CI 1.06 to 1.40) and CHD (HR 1.22, 95% CI 1.06 ~1.40). The associations between long-time exposure to sunlight and SCA were largely attributable to summer (HR 1.22, 95% CI 1.06 to 1.39) and not winter (HR 1.02, 95% CI 0.86 to 1.20), respectively. An hour increase of sunlight exposure was associated with increased risk of SCA in summer (HR, 1.03; 95% CI, 1.01 to 1.05), but not in winter (HR, 1.03, 95% CI, 0.99 to 1.06). Subgroup analysis identified that exposure to long-term sunlight was consistently increased risk of SCA, regardless of age, sex, body mass index, previous cardiovascular diseases, total physical activity, types of physical activity in last 4 weeks, use of sun/UV protection, sedentary time, natural environment percentage (buffer 1000m), and PM2.5. Finally, long-time exposure to sunlight was also associated with increased risk of CHD, but not associated with increased risk of HF hospitalization. Conclusions: Findings from the present study indicate that daily long-time exposure to sunlight that increase in air temperature is a risk factor for SCA and CHD. These associations revealed graded relationship according to the duration of exposure to sunlight and more pronounced in summer. Our results suggest that public health efforts to reduce cardiovascular risk should take a wide range of exposure time to sunlight into account.

The main mechanism of Takotsubo cardiomyopathy (TCM) is catecholamine-induced acute myocardial stunning. Pheochromocytoma, a catecholamine-secreting tumor, can cause several cardiovascular complications, including hypertensive crisis, myocardial infarction, toxic myocarditis, and TCM. A 29-year-old woman presented to our hospital with general weakness, vomiting, dyspnea, and chest pain. The patient was nullipara, 28 weeks’ gestation, and had a cachexic morphology. Her cardiac enzyme levels were elevated and bedside echocardiography showed apical akinesia, suggesting TCM. The next day, she could not feel the fetal movement, and an emergency cesarean section was performed. After delivery, the patient experienced cardiac arrest and was transferred to the intensive care unit for cardiopulmonary resuscitation (CPR). Spontaneous circulation returned after 28 minutes of CPR, but cardiogenic shock continued, and extracorporeal membrane oxygenation (ECMO) was initiated. On the third day of ECMO maintenance, left ventricular ejection fraction improved and blood pressure stabilized. On the eighth day after ECMO insertion, it was removed. However, complications of the left leg vessels occurred, and several surgeries and interventions were performed. A left adrenal gland mass was found on computed tomography and was removed while repairing the leg vessels. Pheochromocytoma was diagnosed and left adrenalectomy was performed.

Accumulating evidence shows that sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce adverse cardiovascular outcomes. However, whether SGLT2i, compared with other antidiabetic drugs, reduce the new development of atrial fibrillation (AF) is unclear. In this study, we compared SGLT2i with dipeptidyl peptidase-4 inhibitors (DPP-4is) in terms of reduction in the risk of AF in individuals with type 2 diabetes. We included 42,786 propensity score-matched pairs of SGLT2i and DPP-4i users without previous AF diagnosis using the Korean National Health Insurance Service database between May 1, 2016, and December 31, 2018. During a median follow-up of 1.3 years, SGLT2i users had a lower incidence of AF than DPP-4i users (1.95 vs. 2.65 per 1,000 person-years; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.55-0.97; p=0.028]). In individuals without heart failure, SGLT2i users was associated with a decreased risk of AF incidence (HR, 0.70; 95% CI 0.52-0.94; p=0.019) compared to DPP-4i users. However, individuals with heart failure, SGLT2i users was not significantly associated with a change in risk (HR, 1.04; 95% CI, 0.44-2.44; p=0.936). In this nationwide cohort study of individuals with type 2 diabetes, treatment with SGLT2i was associated with a lower risk of AF compared with treatment with DPP-4i.

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.

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.