Validity of the diagnosis of acute myocardial infarction in korean national medical health insurance claims data: the korean heart study (1)

SGLT2 Inhibitors vs GLP-1 Receptor Agonists and Clinical Outcomes in Patients With Diabetes With/Without Atrial Fibrillation

CONTEXT

The coexistence of diabetes mellitus and atrial fibrillation (AF) is associated with substantial risks of adverse cardiovascular events.

OBJECTIVE

The relevant outcomes associated with the use of a sodium-glucose cotransporter-2 inhibitor (SGLT2i) vs glucagon-like peptide-1 receptor agonists (GLP-1RAs) among patients with type 2 diabetes (T2D) with/without concomitant AF remain unknown.

METHODS

In this nationwide retrospective cohort study from the Taiwan National Health Insurance Research Database, there were 344 392 and 31 351 patients with T2D without AF, and 11 462 and 816 T2D patients with AF treated with SGLT2is and GLP-1RAs, respectively, from May 1, 2016, to December 31, 2019. Patients were followed from the drug index date until the occurrence of study events, discontinuation of the index drug, or the end of the study period (December 31, 2020), whichever occurred first. We used propensity score-stabilized weight to balance covariates across the 2 medication groups.

RESULTS

The incidence rate of all study outcomes in patients with concomitant AF was much higher than in those without concomitant AF. For the AF cohort, SGLT2i vs GLP-1RA was associated with a lower risk of hospitalization for heart failure (HF) (2.32 vs 4.74 events per 100 person-years; hazard ratio [HR] 0.48, 95% CI 0.36-0.66), with no benefit seen for the non-AF cohort (P for homogeneity < .01). SGLT2i vs GLP-1RA was associated with a lower risk of composite kidney outcomes both in the AF (0.38 vs 0.79 events per 100 person-years; HR 0.47; 95% CI 0.23-0.96) and the non-AF cohorts (0.09 vs 0.18 events per 100 person-years; HR 0.53; 95% CI 0.43-0.64). There were no significant differences in the risk of major adverse cardiovascular events and all-cause mortality in those who received SGLT2i compared with GLP-1RA for the AF or non-AF cohorts.

CONCLUSION

Considering the high risk of developing HF and/or high prevalence of concomitant HF in patients with concomitant diabetes and AF, whether SGLT2is should be the preferred treatment to GLP-1RAs for such a high-risk population requires further investigation.

Cancer risk among air transportation industry workers in Korea: a national health registry-based study

BACKGROUND

Flight attendants face various risk factors in their working environments, particularly occupational exposure to cosmic radiation. This study aimed to assess cancer risk among air transportation industry workers, including flight attendants, in Korea by constructing a cohort using national health registry-based data and analyzing cancer incidence risk.

METHODS

We used the Korea National Health Insurance Service database from 2002 to 2021 to construct a cohort of 37,011 workers in the air transportation industry. Cancer incidence was defined using the tenth version of the International Classification of Diseases. We calculated the age- and sex-specific standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) by applying the cancer incidence rate of the general population between 2002 and 2019.

RESULTS

Approximately 5% of the cohort developed cancer. Overall, the cancer incidence in the cohort was similar to or lower than that of the general population, with the SIRs for all cancers being lower. However, significantly higher SIRs were observed for nasopharyngeal cancer (SIR, 3.21; 95% CI, 1.71-5.48) and non-Hodgkin lymphoma (SIR, 1.57; 95% CI, 1.02-2.32) in male workers and breast and genital cancer (SIR, 1.51; 95% CI, 1.34-1.70) and thyroid cancer (SIR, 1.25; 95% CI, 1.05-1.47) in female workers.

CONCLUSIONS

The lower overall cancer incidence among air transportation industry workers observed in this study could indicate the "healthy worker effect"; however, the incidences of certain cancers were higher than those in the general population. Given that these workers are exposed to multiple occupational and lifestyle-related risk factors, including cosmic radiation, further studies are necessary to determine radiation-induced cancer risk while considering potential confounding factors.

Proton Pump Inhibitor for Gastrointestinal Bleeding in Patients with Myocardial Infarction on Dual-Antiplatelet Therapy: A Nationwide Cohort Study

BACKGROUND

Guidelines provide various recommendations for the use of proton pump inhibitors (PPI) to prevent upper gastrointestinal (UGI) bleeding in acute myocardial infarction (MI) treatment with dual antiplatelet therapy (DAPT). We evaluated the effects of PPIs in reducing the risk of severe UGI bleeding in patients with MI receiving DAPT.

METHODS

This retrospective cohort study included patients admitted for acute MI between 2014 and 2018, based on a nationwide health claims database in Korea. Primary outcome was admission for severe UGI bleeding requiring transfusion within 1 year of MI diagnosis. A multivariable Cox regression model was used to calculate the association between PPI use and severe UGI bleeding risk.

RESULTS

Of 100,556 patients with MI on DAPT (mean age, 63.7 years; 75.4% men), 37% were prescribed PPIs. Based on risk assessment for UGI bleeding, among 6,392 (6.4%) high-risk and 94,164 (93.6%) low-risk patients, 50.5% and 35.8% received PPIs, respectively. Overall, 0.5% of the patients experienced severe UGI bleeding within 1 year after MI. The use of PPI was associated with a reduced risk of severe UGI bleeding (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.47-0.70; P < 0.001). The benefits of PPIs were consistent in high-risk (HR, 0.71; 95% CI, 0.45-1.13; P = 0.147) and low-risk (HR, 0.54; 95% CI, 0.43-0.68; P < 0.001) patients (P for interaction = 0.481).

CONCLUSIONS

Among Korean patients with MI receiving DAPT, PPIs were underutilized, even among those at high risk of severe UGI bleeding. Nonetheless, PPI use reduced severe UGI bleeding in low- and high-risk groups.

Angiotensin Receptor Blockers Versus Angiotensin Converting Enzyme Inhibitors in Acute Myocardial Infarction Without Heart Failure

BACKGROUND

Whether angiotensin II receptor blockers (ARBs) can be an alternative to angiotensin-converting enzyme inhibitors (ACEIs) in patients without heart failure (HF) after acute myocardial infarction (MI) remains controversial. The aim of this study was to compare clinical outcomes between initial ARB and ACEI therapy in patients with MI without HF.

METHODS

Between 2010 and 2016, a total of 31,013 patients who underwent coronary revascularization for MI with prescription of ARBs or ACEIs at hospital discharge were enrolled from the Korean nationwide medical insurance data. Patients who had HF at index MI were excluded. The primary outcome was all-cause death. The secondary outcomes included recurrent MI, hospitalization for new heart HF, stroke, and a composite of each outcome.

RESULTS

Of 31,013 patients, ARBs were prescribed in 12,685 (40.9%) and ACEIs in 18,328 (59.1%). Patients receiving ARBs had a lower discontinuation rate compared with those receiving ACEIs (28.2% vs 43.5%, adjusted hazard ratio [HR] 0.34; 95% confidence interval [CI] 0.31-0.37; P < .01). During a median follow-up of 2.2 years, 2480 patients died. The incidence rate of all-cause death in patients receiving ARBs and those receiving ACEIs was 27.7 and 22.9 per 1000 person-years, respectively (adjusted HR 1.04; 95% CI 0.95-1.13; P = .40). There were no significant differences in the secondary outcomes between patients receiving ARBs and those receiving ACEIs, except stroke (19.2 vs 13.6 per 1000 person-years; adjusted HR 1.17; 95% CI 1.04-1.32; P = .01). In a subgroup analysis, a higher mortality was observed with ARBs compared with ACEIs in patients with diabetes.

CONCLUSIONS

In this nationwide cohort, there was no significant difference in the incidence of all-cause death between ARBs and ACEIs as discharge medications in patients with myocardial infarction without heart failure. Angiotensin II receptor blockers would be an alternative to ACEIs for those intolerant to ACEI therapy.

Increased risk of cardiovascular disease among kidney cancer survivors: a nationwide population-based cohort study

Background

Cardiovascular disease (CVD) is a major concern of morbidity and mortality among cancer survivors. However, few evidence exists on the short- and long-term risk of CVD in kidney cancer (KCa) survivors.

Methods

In this nationwide, large population-based retrospective cohort study, we used the Korean national health insurance and medical checkup survey linkage database (2007-2021), drawn from the entire Korean population. We included adults diagnosed with KCa as the first primary cancer and matched them to an individual without KCa at a 1:5 ratio. The primary outcome was CVD incidence, including myocardial infarction, stroke, atrial fibrillation, heart failure, peripheral arterial occlusion, and venous thromboembolism (VTE). We evaluated CVD risk at 6 months, 1 year, and 5 years following cancer diagnosis, using Fine-Gray competing risk models that accounted for death as a competing factor.

Results

A total of 149,232 participants were included (KCa survivors: N=20,093 and matched non-KCa individuals: N=129,139). After 6-month follow-up, KCa survivors showed an increased risk of CVD compared to the general population (subdistribution hazard ratio (HR) 2.70, 95% confidence interval (CI) 2.31-3.15). After 1 year, KCa survivors had a higher risk of CVD (HR=1.77, 95% CI: 1.56-2.00). After 5 years, this elevated CVD risk remained (HR=1.10, 95% CI: 1.03-1.18), with VTE identified as the primary contributing disease (HR=3.05, 95% CI:2.59-3.59).

Conclusion

KCa survivors had an increased risk of CVD up to 5 years after cancer diagnosis compared to the general population. Our findings emphasize the importance of comprehensive healthcare management for both CVD and KCa throughout cancer survivorship.

The influence of advanced maternal age on congenital malformations, short- and long-term outcomes in offspring of nulligravida: a Korean National Cohort Study over 15 years

OBJECTIVE

To assess the influence of advanced maternal age on congenital malformations, short- and long-term outcomes in offspring of nulligravida.

METHODS

A retrospective study was conducted using the Korean National Health Insurance Service database spanning from January 2005 to December 2019. All live-born offspring of nulligravida (n=3,685,817) were included. The maternal age was subdivided into the following subgroups: <25 years (n=153,818), 25-29 years (n=845,355), 30-34 years (n=1,738,299), 35-39 years (n=787,530), 40-44 years (n=151,519), and >44 years (n=9,296). Outcomes were assessed based on International Classification of Diseases-10 codes. Adjusted odds ratios (aOR) were calculated with the group of 25-29 years as a reference.

RESULT

Most congenital malformations showed an age dependent increase, but cleft lip and abdominal wall defect exhibited a U-shape curve, indicating an increase even in those <25 years old. Similarly, various disorders included in the neonatal composite outcomes from short-term outcomes showed aged dependent escalation. However, the preterm birth from the short-term outcome and most of the long-term developmental outcomes, except for motor developmental delay and Tics, showed a U-shaped pattern. The aOR of autism and cerebral palsy, showing the most obvious U-shaped curved in the long-term outcomes, was 1.50 (95% confidence interval [CI], 1.24-1.82) and 1.54 (95% CI, 1.17-2.03), respectively in the group >44 years old and 1.18 (95% CI, 1.11-1.25) and 1.19 (95% CI, 1.09-1.30) in <25 years old group.

CONCLUSION

Overall, an advanced maternal age has an age-dependent correlation with most congenital malformations and shortand long-term outcomes of neonates.

Optimal Antithrombotic Therapy Beyond 1-Year After Coronary Revascularization in Patients With Atrial Fibrillation

BACKGROUND

Currently, non-vitamin K-antagonist oral anticoagulant (NOAC) monotherapy has been suggested as the optimal antithrombotic therapy for atrial fibrillation (AF) beyond one year after coronary revascularization. The aim of this study was to compare the outcomes between NOAC monotherapy and NOAC plus antiplatelet combination therapy using real-world data.

METHODS

Between 2015 and 2020, patients with AF who had received NOACs beyond one year after coronary revascularization were enrolled from Korean national insurance data. We emulated a pragmatic sequence of trials between the NOAC monotherapy and the antiplatelet combination therapy followed by propensity score matching. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCEs), a composite of all-cause death, myocardial infarction, and stroke.

RESULTS

Among 206,407 person-trials from 4,465 individuals, we compared 3,275 pairs of the monotherapy and the matched combination therapy. During a median follow-up of 1.24 years, the incidence rate of MACCE was 19.4% and 20.0% per patient-year in the monotherapy group and the antiplatelet combination group, respectively (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.88-1.05; P = 0.422). Compared with the antiplatelet combination group, the monotherapy group had a significantly lower incidence rate of major bleeding, defined as intracranial bleeding or gastrointestinal bleeding requiring hospitalization (2.8% vs. 3.6% per patient-year; HR, 0.78; 95% CI, 0.62-0.97; P = 0.024).

CONCLUSION

As an antithrombotic therapy for AF beyond one year after coronary revascularization, NOAC monotherapy was associated with a similar risk of MACCE and a lower risk of major bleeding compared to NOAC plus antiplatelet combination therapy.

Association of body composition indices with cardiovascular outcomes: a nationwide cohort study

BACKGROUND

Previous studies regarding BMI (kg/m2) and associated cardiovascular outcomes yield inconsistent results.

OBJECTIVES

We aimed to investigate the association between body composition and cardiovascular outcomes according to BMI categories in the Korean general population.

METHODS

A total of 2,604,401 participants were enrolled in this nationwide cohort study using the National Health Insurance Service-Health Checkup data set. Predicted lean BMI (pLBMI), body fat mass index (pBFMI), and appendicular skeletal muscle mass index (pASMMI) were calculated using validated anthropometric prediction equations. A multivariable time-dependent Cox regression analysis was conducted to assess the association with cardiovascular outcomes. The results were presented with adjusted hazard ratios (HRs) with 95% confidence intervals (CIs), considering BMI categories (BMI < 18.5, BMI 18.5-24.9, BMI 25-29.9, and BMI ≥ 30).

RESULTS

Higher pLBMI and pASMMI were correlated with a reduced risk of composite cardiovascular outcomes. For pLBMI, HR was 0.910 (95% CI: 0.908, 0.913, P < 0.001) for males and 0.905 (95% CI: 0.899, 0.910, P < 0.001) for females. For pASMMI, HR was 0.825 (95% CI: 0.820, 0.829, P < 0.001) for males and 0.788 (95% CI: 0.777, 0.800, P < 0.001) for females. Conversely, a higher pBFMI was associated with an increased risk, with HR of 1.082 (95% CI: 1.071, 1.093, P < 0.001) for males and 1.181 (95% CI: 1.170, 1.192, P < 0.001) for females. Subgroup analysis based on BMI categories revealed no significant risk association for pBFMI in the BMI < 18.5 group. In the group with BMI ≥ 30, neither pLBMI nor pASMMI demonstrated a significant risk association.

CONCLUSIONS

Our results highlight the value of pLBMI, pBFMI, and pASMMI as variables for assessing risk of composite cardiovascular outcomes. The significance of indicators may vary depending on BMI categories.

Impact of anemia requiring transfusion or erythropoiesis-stimulating agents on new-onset cardiovascular events and mortality after continuous renal replacement therapy

Anemia is common in critically ill patients undergoing continuous renal replacement therapy (CRRT). We investigated the impact of anemia requiring red blood cell (RBC) transfusion or erythropoiesis-stimulating agents (ESAs) on patient outcomes after hospital discharge in critically ill patients with acute kidney injury (AKI) requiring CRRT. In this retrospective cohort study using the Health Insurance Review and Assessment database of South Korea, 10,923 adult patients who received CRRT for 3 days or more between 2010 and 2019 and discharged alive were included. Anemia was defined as the need for RBC transfusion or ESAs. Outcomes included cardiovascular events (CVEs) and all-cause mortality after discharge. The anemia group showed a tendency to be older with more females and had more comorbidities compared to the control group. Anemia was not associated with an increased risk of CVEs (adjusted hazard ratio [aHR]: 1.05; 95% confidence interval [CI]: 0.85-1.29), but was associated with an increased risk of all-cause mortality (aHR: 1.41; 95% CI 1.30-1.53). For critically ill patients with AKI requiring CRRT, anemia, defined as requirement for RBC transfusion or ESAs, may increase the long-term risk of all-cause mortality.

Association between age at diagnosis of type 2 diabetes and cardiovascular morbidity and mortality risks: A nationwide population-based study

AIMS

We aimed to investigate the association between the age at diagnosis of type 2 diabetes and the risk of cardiovascular (CVD) outcomes in comparison with nondiabetic counterparts.

METHODS

A total of 634,350 patients with newly diagnosed type 2 diabetes between January 1, 2012, and December 31, 2014 were included in a Korean population cohort study. Nondiabetic matched controls were selected from the general population in a 1:2 ratio. Participants were followed until the end of 2019 for CVD outcomes and mortality.

RESULTS

During 5.7 years of follow-up, patients with type 2 diabetes diagnosed at ≤40 years of age had the highest excess risk for most outcomes relative to controls, with an adjusted hazard ratio (HR) (95 % CI) of 6.08 (5.51-6.70) for total mortality, 7.10 (6.66-7.58) for hospitalization for heart failure, and 5.04 (4.86-5.24) for coronary heart disease. All risks attenuated progressively with each increasing decade of diagnostic age.

CONCLUSION

In this population-based cohort study, a younger age at diagnosis of type 2 diabetes was associated with a higher relative risk of mortality and CVD outcomes. Therefore, primary prevention of type 2 diabetes is desirable at all ages but is particularly important at younger ages.

Long-Term Survival Analysis of 5619 Total Ankle Arthroplasty and Patient Risk Factors for Failure

BACKGROUND

Total ankle arthroplasty (TAA) has higher complication and failure rates compared to other surgical joint replacement procedures despite technological advances. This study aimed to find the long-term survivability of the TAA procedure and identify the patient risk factors for failure with one of the largest cohorts of patients in the literature.

METHODS

This retrospective cohort study involving cases between 2007 and 2018 analyzed patients who received an index primary TAA procedure in Korea. A total of 5619 cases were included in the final analysis. The TAA failure was defined as either a case with revision arthroplasty or a case with TAA implant removal and arthrodesis performed after primary TAA.

RESULTS

During the study period, the 5-year survival rate was 95.4% (95% CI, 94.7-96.1%), and the 10-year survival rate was 91.1% (95% CI, 89.1-93.1%). A younger age (<55 years, adjusted hazard ratio [AHR], 1.725; 55-64 years, AHR, 1.812; p < 0.001 for both), chronic pulmonary disease (AHR, 1.476; p = 0.013), diabetes (AHR, 1.443; p = 0.014), and alcohol abuse (AHR, 1.524; p = 0.032) showed a significantly high odds ratio for primary TAA failure in Cox regression analysis.

CONCLUSION

The 10-year TAA survivorship rate was 91.1%. A younger age, chronic pulmonary disease, diabetes, and heavy alcohol consumption are risk factors for TAA.

Identification of acute myocardial infarction and stroke events using the National Health Insurance Service database 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.

Risk of depression and anxiety disorders according to long-term glycemic variability

BACKGROUND

Poor glycemic control has been linked to psychiatric symptoms. However, studies investigating the relationship between glycemic variability (GV) and depression and anxiety disorders are limited. We investigated the association of GV with depression and anxiety disorders. In addition, the relationship between trends in fasting plasma glucose (FPG) levels and these disorders were explored.

METHODS

We analyzed the National Health Insurance Service-National Sample Cohort database (2002-2013) with 151,814 participants who had at least three health screenings between 2002 and 2010. Visit-to-visit FPG variability was measured as variability independent of the mean (VIM). Depression and anxiety disorders were diagnosed using ICD-10 codes (F41 for anxiety and F32 or F33 for depression) after index date. We analyzed the association between GV and incidences of these disorders using Kaplan-Meier and Cox proportional hazards methods. Trajectory analysis was conducted to explore the relationship between FPG trends and these disorders.

RESULTS

During follow-up, 7166 and 14,149 patients were newly diagnosed with depression and anxiety disorders, respectively. The highest quartile group of FPG-VIM had a greater incidence of depression and anxiety than the lowest quartile group, with adjusted hazard ratios of 1.09 (95 % confidence interval [CI]: 1.02-1.17) and 1.08 (95 % CI: 1.03-1.14). Group with persistent hyperglycemia, identified through trajectory clustering of FPG levels, had a 1.43-fold increased risk of depression compared to those with consistently low FPG levels.

LIMITATIONS

Potential selection bias by including participants with at least three health screenings.

CONCLUSIONS

High GV and persistent hyperglycemia are associated with increased incidence of depression and anxiety disorders.

Mortality After Acute Coronary Syndrome in Human Immunodeficiency Virus Infection with Optimal Adherence: A Nationwide Study

BACKGROUND

There have been few studies on the outcome of acute coronary syndrome (ACS) in human immunodeficiency virus (HIV) infection in the era when antiretroviral therapy (ART) is generalized and most of them have achieved viral suppression. Using claims data, we aimed to assess the mortality after atherosclerotic cardiovascular events in people with HIV (PWH) who maintain optimal adherence to ART.

MATERIALS AND METHODS

We used claims data from the National Health Insurance of the Korea to confirm newly diagnosed PWH from 2009 to 2019, and measured ART adherence. ACS and mortality were confirmed in PWH who showed optimal adherence to ART.

RESULTS

Among 7,100 PWH with optimal adherence and during 27,387 person-year of follow-up duration, ACS was confirmed in 140 (2.0%) cases, which was 1.3 times greater than statistics of the Korean general population (511.0 vs. 383.1 per 100,000). Acquired immunodeficiency syndrome, hypertension, dyslipidemia, and diabetes mellitus were associated with the development of ACS in PWH with optimal adherence. Mortality was confirmed in 10 cases, which is 7.1% overall and 2.9% when limited to myocardial infarction. It was comparable with the mortality rate of the Korean general population after myocardial infarction (8.9%).

CONCLUSION

ACS prevalence was higher in PWH even when optimal adherence was maintained. However, mortality after ACS was comparable to that in the HIV-negative population.

A Decline in Overutilization of Transfusion after Total Knee Arthroplasty Using Pharmacological Agents for Patient Blood Management in South Korea: An Analysis Based on the Korean National Health Insurance Claims Database from 2008 to 2019

Background

This study aimed to evaluate the annual trends of transfusion rates and utilization of blood management agents in total knee arthroplasty (TKA) based on the operation type and to analyze the risk factors of transfusion after TKA.

Methods

Using the Korean National Insurance claims database of 797,106 primary and revision TKAs between January 2008 and October 2019, data on the patients' characteristics, comorbidities, utilization of transfusion, and blood management agents were collected. The patients were categorized into three groups based on the operation type: primary, revision, and simultaneous bilateral TKA. The transfusion rate and utilization of blood management agents (intraoperative tranexamic acid [TXA] and preoperative iron supplements) were compared, and the risk factors for transfusion were evaluated.

Results

After excluding the inaccurate data, 730,554 arthroplasties (636,292 primary, 10,540 revision, and 41,861 simultaneous bilateral TKAs) were identified. The transfusion rates of primary, revision, and simultaneous bilateral TKAs in 2019 were 64.0%, 67.7%, and 68.9%, respectively, which were significantly decreased compared with 83.2%, 88.0%, and 92.5% in 2008, respectively (p < 0.001). Conversely, the utilization of intraoperative TXA and preoperative iron supplements was significantly increased from 4.6% and 13.8%, respectively, in 2008 to 52.4% and 27.0%, respectively, in 2019 (p < 0.001). The utilization of intraoperative TXA and preoperative iron supplements significantly lowered the risk of transfusion after TKA (odds ratio [OR], 0.20; p < 0.001 and OR, 0.71; p < 0.001).

Conclusions

The transfusion rate after TKA decreased gradually from 83.5% to 64.5% between 2008 and 2019 in South Korea corresponding with the increased utilization of blood management agents. Therefore, consistent attention to patient blood management should be emphasized to reduce the transfusion rate after TKA.

Effects of urinary tract infection during the first years of life in subsequent growth: a nationwide comparative matched cohort study

Background

Although various childhood illnesses are known to influence growth status, the impact of urinary tract infections (UTI) on subsequent childhood growth remains unclear. This study was conducted to examine the association between UTI during infancy and growth status at 30-36 months.

Methods

Nationwide population-based matched cohort study was done using data from the Korean National Health Insurance System (NHIS) and the Korean National Health Screening Program for Infants and Children (NHSPIC) between January 2018 and December 2020. Height and weight standard deviation scores (SDSs) at the fourth Korean NHSPIC conducted at 30-36 months were compared between children who experienced UTI during infancy and age- and sex-matched controls. We used weighted multiple linear regression analysis with inverse probability of treatment weighting (IPTW) and identified differences between the two groups using β coefficient with corresponding 95% confidence intervals (CIs).

Results

We analyzed 84,519 children diagnosed with UTI during infancy and 84,519 age- and sex-matched controls. The height SDS between children who experienced UTI and the control group was not statistically different (β coefficient for height SDS, -0.0034; 95% CI: -0.0121 to 0.0054). However, the body mass index (BMI) SDS was significantly higher in children who had experienced UTI (β coefficient for BMI SDS, 00426; 95% CI: 0.0304 to 0.0547). Subgroup and sensitivity analysis showed consistent results.

Conclusions

Our findings suggest that a history of UTI during infancy is associated with high BMI measured at 30-36 months.

Validation of ICD-10-CM Diagnostic Codes for Identifying Patients with ST-Elevation and Non-ST-Elevation Myocardial Infarction in a National Health Insurance Claims Database

Purpose

Distinguishing ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) is crucial in acute myocardial infarction (AMI) research due to their distinct characteristics. However, the accuracy of International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes for STEMI and NSTEMI in Taiwan's National Health Insurance (NHI) database remains unvalidated. Therefore, we developed and validated case definition algorithms for STEMI and NSTEMI using ICD-10-CM and NHI billing codes.

Patients and Methods

We obtained claims data and medical records of inpatient visits from 2016 to 2021 from the hospital's research-based database. Potential STEMI and NSTEMI cases were identified using diagnostic codes, keywords, and procedure codes associated with AMI. Chart reviews were then conducted to confirm the cases. The performance of the developed algorithms for STEMI and NSTEMI was assessed and subsequently externally validated.

Results

The algorithm that defined STEMI as any STEMI ICD code in the first three diagnosis fields had the highest performance, with a sensitivity of 93.6% (95% confidence interval [CI], 91.7-95.2%), a positive predictive value (PPV) of 89.4% (95% CI, 87.1-91.4%), and a kappa of 0.914 (95% CI, 0.900-0.928). The algorithm that used the NSTEMI ICD code listed in any diagnosis field performed best in identifying NSTEMI, with a sensitivity of 82.6% (95% CI, 80.7-84.4%), a PPV of 96.5% (95% CI, 95.4-97.4), and a kappa of 0.889 (95% CI, 0.878-0.901). The algorithm that included either STEMI or NSTEMI ICD codes listed in any diagnosis field showed excellent performance in defining AMI, with a sensitivity of 89.4% (95% CI, 88.2-90.6%), a PPV of 95.6% (95% CI, 94.7-96.4%), and a kappa of 0.923 (95% CI, 0.915-0.931). External validation confirmed these algorithms' efficacy.

Conclusion

Our results provide valuable reference algorithms for identifying STEMI and NSTEMI cases in Taiwan's NHI database.

Impact of dementia and drug compliance on patients with acute myocardial infarction

BACKGROUND

In South Korea, the number of people with dementia is rising at a worrisome rate, and many of them also have acute myocardial infarction (AMI), a disease with a high mortality rate.

HYPOTHESIS

We speculated that dementia and drug compliance have significant impact on the mortality of patients with AMI.

METHODS

The study derived data from the National Health Insurance Service-Senior for a retrospective cohort study. The total number of patients diagnosed with AMI for the first time between 2007 and 2013 was 16 835, among whom 2021 had dementia. Medication possession ratio (MPR) was used to assess medication adherence.

RESULTS

AMI patients with dementia had unfavorable baseline characteristics; they had significantly higher risk of all-cause mortality (hazard ratio [HR]: 2.49; 95% confidence interval [CI]: 2.34-2.66; p < .001) and lower MPR (aspirin: 21.9% vs. 42.8%; p < .001). AMI patients were stratified by presence of dementia and medication adherence, and the survival rate was the highest among those with no dementia and good adherence, followed by those with no dementia and poor adherence, those with dementia and good adherence, and those with dementia and poor adherence. The multivariable analysis revealed that dementia (HR: 1.64; 95% CI: 1.53-1.75; p < .001) and poor adherence to medication (HR: 1.60; 95% CI: 1.49-1.71; p < .001) had a significant association with all-cause mortality in AMI patients.

CONCLUSIONS

AMI patients with dementia have a higher mortality rate. Their prognosis is negatively affected by their poorer medication adherence than patients without dementia.

Active surveillance for adverse events of influenza vaccine safety in elderly cancer patients using self-controlled tree-temporal scan statistic analysis

Both cancer patients and the elderly are at high risk of developing flu complications, so influenza vaccination is recommended. We aimed to evaluate potential adverse events (AEs) following influenza vaccination in elderly cancer patients using the self-controlled tree-temporal scan statistic method. From a large linked database of Korea Disease Control and Prevention Agency vaccination data and the National Health Insurance Service claims data, we identified cancer patients aged over 65 who received flu vaccines during the 2016/2017 and 2017/2018 seasons. We included all the outcomes occurring on 1-84 days post-vaccination and evaluated all temporal risk windows, which started 1-28 days and ended 2-42 days. Patients who were diagnosed with the same disease during a year prior to vaccination were excluded. We used the hierarchy of ICD-10 to identify statistically significant clustering. This study included 431,276 doses of flu vaccine. We detected signals for 1 set: other dorsopathies on 1-15 days (attributable risk 16.5 per 100,000, P = 0.017). Dorsopathy is a known AE of influenza vaccine. No statistically significant clusters were found when analyzed by flu season. Therefore, influenza vaccination is more recommended for elderly patients with cancer and weakened immune systems.

Comparison Between Fimasartan Versus Other Angiotensin Receptor Blockers in Patients With Heart Failure After Acute Myocardial Infarction

BACKGROUNDS

Fimasartan is the most recently developed, potent, and long-acting angiotensin II receptor blocker (ARB). However, data are limited regarding treatment effects of fimasartan in patients with heart failure.

METHODS

Between 2010 and 2016, patients who underwent coronary revascularization for myocardial infarction (MI) with heart failure and prescription of ARB at hospital discharge were enrolled from the Korean nationwide medical insurance data. Clinical outcomes were compared between patients receiving fimasartan and those receiving other ARBs (candesartan, valsartan, losartan, telmisartan, olmesartan, and irbesartan). The primary outcome was a composite of all-cause death, recurrent MI, hospitalization for heart failure, and stroke.

RESULTS

Of 2,802 eligible patients, fimasartan was prescribed to 124 patients (4.4%). During a median follow-up of 2.2 years (interquartile range, 1.0-3.9), 613 events of the primary outcome occurred. There was no significant difference in the primary outcome between patients receiving fimasartan and those receiving other ARBs (adjusted hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.46-1.45). Compared with patients receiving other ARBs, those receiving fimasartan had comparable incidence of all-cause death (adjusted HR, 0.70; 95% CI, 0.30-1.63), recurrent MI (adjusted HR, 1.28; 95% CI, 0.49-3.34), hospitalization for heart failure (adjusted HR, 0.70; 95% CI, 0.27-1.84), and stroke (adjusted HR, 0.59; 95% CI, 0.18-1.96).

CONCLUSION

In this nationwide cohort, fimasartan, compared with other ARBs, had comparable treatment effects for a composite of all-cause death, recurrent MI, hospitalization for heart failure, and stroke in patients with heart failure after MI.

A comparison of methods for the measurement of adherence to antihypertensive multidrug therapy and the clinical consequences: a retrospective cohort study using the Korean nationwide claims database

OBJECTIVES

In observational studies, the methods used to measure medication adherence may affect assessments of the clinical outcomes of drug therapy. This study estimated medication adherence to multidrug therapy in patients with hypertension using different measurement methods and compared their impacts on clinical outcomes.

METHODS

This was a retrospective cohort study using the Korean National Health Insurance Service-National Sample Cohort database (2006-2015). Adults diagnosed with hypertension who initiated multidrug antihypertensive therapy in the index year 2007 were included. Adherence was defined as over 80% compliance. Adherence to multidrug antihypertensive therapy was measured in 3 ways using the proportion of days covered (PDC) with 2 approaches to the end-date of the study observations: PDC with at least one drug (PDCwith≥1), PDC with a duration weighted mean (PDCwm), and the daily polypharmacy possession ratio (DPPR). The primary clinical outcome was a composite of cardiovascular and cerebrovascular disease-specific hospitalizations or all-cause mortality.

RESULTS

In total, 4,226 patients who initiated multidrug therapy for hypertension were identified. The mean adherence according to the predefined measurements varied from 72.7% to 79.8%. Non-adherence was associated with an increased risk of a primary outcome. The hazard ratios (95% confidence intervals, CIs) primary outcomes varied from 1.38 (95% CI, 1.19 to 1.59) to 1.44 (95% CI, 1.25 to 1.67).

CONCLUSIONS

Non-adherence to multidrug antihypertensive therapy was significantly associated with an increased risk of a primary clinical outcome. Across the varying estimates based on different methods, medication adherence levels were similar. These findings may provide evidence to support decision-making when assessing medication adherence.

De novo major cardiovascular events in kidney transplant recipients: a comparative matched cohort study

BACKGROUND

Although cardiovascular disease is known to be one of the leading causes of death after kidney transplantation (KT), evidence on the risk difference of de novo major adverse cardiovascular events (MACEs) in kidney transplant recipients (KTRs) compared with that in dialysis patients or the general population (GP) remains rare.

METHODS

We identified KTRs using the nationwide health insurance database in South Korea and then 1:1 matched them with the dialysis and GP controls without a pre-existing MACE. The primary endpoint was defined as de novo MACEs consisting of myocardial infarction, coronary revascularization and ischemic stroke. The secondary endpoints were all-cause mortality and death-censored graft failure (DCGF) in KTRs.

RESULTS

We included 4156 individuals in each of the three groups and followed them up for 4.7 years. De novo MACEs occurred in 3.7, 21.7 and 2.5 individuals per 1000 person-years in the KTRs, dialysis controls and GP controls, respectively. KTRs showed a lower MACE risk {adjusted hazard ratio (aHR) 0.16 [95% confidence interval (CI) 0.12-0.20], P < .001} than dialysis controls, whereas a similar MACE risk to GP controls [aHR 0.81 (95% CI 0.52-1.27), P = .365]. In addition, KTRs showed a similar MACE risk compared with the GP group, regardless of age, sex and the presence of comorbidities, including hypertension, diabetes and dyslipidemia. Among KTRs, de novo MACEs were associated with an increased risk of all-cause mortality, but not with DCGF.

CONCLUSIONS

De novo MACEs in KTRs were much lower than that in dialysis patients and had a similar risk to the GP, but once it occurred it caused elevated mortality risk in KTRs.

Impact of Chronic Obstructive Pulmonary Disease on Outcomes After Total Joint Arthroplasty: A Meta-analysis and Systematic Review

Background

Comorbid chronic obstructive pulmonary disease (COPD) is increasingly common and may have an adverse impact on outcomes in patients undergoing total joint arthroplasty (TJA) of lower extremity. The purpose of this meta-analysis is to compare the postoperative complications between COPD and non-COPD patients undergoing primary TJA including total hip and knee arthroplasty.

Methods

PubMed, EMBASE, and Cochrane Library were systematically searched for relevant studies published before December 2021. Postoperative outcomes were compared between patients with COPD versus those without COPD as controls. The outcomes were mortality, re-admission, pulmonary, cardiac, renal, thromboembolic complications, surgical site infection (SSI), periprosthetic joint infection (PJI), and sepsis.

Results

A total of 1,002,779 patients from nine studies were finally included in this meta-analysis. Patients with COPD had an increased risk of mortality (OR [odds ratio] = 1.69, 95% confidence interval [CI] 1.42-2.02), re-admission (OR = 1.54, 95% CI 1.38-1.71), pulmonary complications (OR = 2.73, 95% CI 2.26-3.30), cardiac complications (OR = 1.40, 95% CI 1.15-1.69), thromboembolic complications (OR = 1.21, 95% CI 1.15-1.28), renal complications (OR = 1.50, 95% CI 1.14-1.26), SSI (OR = 1.23, 95% CI 1.18-1.30), PJI (OR = 1.26, 95% CI 1.15-1.38), and sepsis (OR = 1.36, 95% CI 1.22-1.52).

Conclusion

Patients with comorbid COPD showed an increased risk of mortality and postoperative complications following TJA compared with patients without COPD. Therefore, orthopedic surgeons can use the study to adequately educate these potential complications when obtaining informed consent. Furthermore, preoperative evaluation and medical optimization are crucial to minimizing postoperative complications from arising in this difficult-to-treat population.

Level of evidence

Level III.

Registration

None.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00794-2.

Do statins benefit low-risk population for primary prevention of atherosclerotic cardiovascular disease: A retrospective cohort study

The reported beneficial effects of statins on cardiovascular outcome based on risk assessment are inconsistent. Therefore, we investigated statin therapy effectiveness for the primary prevention of cardiovascular disease (CVD), according to the Korean Risk Prediction Model (KRPM). Subjects aged 40–79 years with low density lipoprotein cholesterol (LDL-C) of < 190 mg/dL and without CVD history were categorized as statin users or non-users using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database, Korea, 2002–2015. The 10-year atherosclerotic CVD (ASCVD) risk was calculated using the validated KRPM and categorized as low, borderline, intermediate, or high-risk groups; the incidence of major adverse cardiovascular events (MACEs) was compared over a mean follow-up period of 5.7 years using Cox proportional hazard models. The MACE incidence risk was decreased in statin users [hazard ratio (HR) 0.90, 95% confidence interval (CI) (0.84–0.98)]. However, there was an increased risk of MACE incidence in low-risk statin users [HR 1.80, 95% CI (1.29–2.52)], and no significant relationship was identified between statin use and MACE in the borderline [HR 1.15, 95% CI (0.86–1.54)] and intermediate-risk [HR 0.94, 95% CI (0.85–1.03)] groups. The risk of MACE incidence decreased only in the high CVD risk group among statin users. Statin use is not associated with MACE reduction in low- to intermediate-risk participants. Therefore, individuals with LDL-C level of < 190 mg/dL and low ASCVD risk should consider statin therapy only when CVD risk is proved obvious using an appropriate ASCVD risk tool.

Risk of revision in UKA versus HTO: a nationwide propensity score-matched study

INTRODUCTION

Our study aims to investigate the incidence rate and risk factors for subsequent revision in patients treated with UKA compared with those treated with HTO.

METHODS

In this retrospective nationwide cohort study, we used data from the Korean National Health Insurance claims database from January 1, 2009 to December 31, 2017. We compared patients who had undergone UKA or HTO as the primary surgical procedure longer than two years prior. We used multivariable logistic regression models to compare risk of revision between the groups after propensity matching with inverse probability of treatment weighting (IPTW). Revision was defined as conversion to total knee arthroplasty (TKA) after primary UKA or HTO.

RESULTS

In this study, 73,902 patients with UKA and 72,215 patients with HTO were identified after applying IPTW. The risk of revision during the entire study period was higher for patients with HTO than for patients with UKA (adjusted hazard ratio [HR] = 1.42). Kaplan-Meier 8-years survival was 96.8% in the UKA group and 95.1% in the HTO group. Patients with HTO who were at higher risk of revision had advanced age (60-69 years [HR = 2.17, 95% CI 1.76-2.67] and 70-79 years [HR = 2.89, 95% CI 1.81-4.62]), female sex (HR = 1.41, 95% CI 1.19-1.66), CHF (HR = 3.12, 95% CI 1.25-7.78), COPD (HR = 1.68, 95% CI 1.34-2.10), PVD (HR = 1.75, 95% CI 1.10-2.78), and CVA or TIA (HR = 1.87, 95% CI 1.13-3.08) compared with those with UKA.

CONCLUSION

Risk of revision was higher for patients with HTO than for patients with UKA. Risk factors for subsequent revision in patients with HTO were advanced age (60-69, 70-79), female sex, and comorbidities such as CHF, COPD, PVD, CVA, or TIA. However, orthopedic surgeons should also consider that TKA conversion from UKA has higher risk of revision than TKA conversion from HTO before choosing between UKA and HTO.

Clinical and economic impact of changing reimbursement criteria for statin treatment among patients with type 2 diabetes mellitus in South Korea

Aim: Patients with type 2 diabetes mellitus (T2DM) in South Korea can be reimbursed for statins if they have a low-density lipoprotein cholesterol (LDL-C) level of ≥100 mg/dL. We aimed to explore the clinical and economic benefit received by T2DM patients when easing the current criteria for statin treatment by lowering the LDL-C threshold from 100 mg/dL to 70 mg/dL.

Methods: We used a static course model with a 5-year period to compare the following two scenarios in T2DM patients with no history of cardiovascular (CV) events: the current criteria covering LDL-C ≥100 mg/dL and the revised criteria covering LDL-C ≥70 mg/dL. The number of target patients was estimated based on previous Korean studies on patients with T2DM. The current mix of treatments used for T2DM and costs involving CV events were estimated using the National Health Insurance Service–National Health Screening Cohort database. The baseline CV event rates and case fatality were estimated using NHIS Customized database, including 50% patients who were prescribed atorvastatin and 100% who were not prescribed statins between 2009 and 2012 among patients with T2DM in the entire Korean population. After propensity score matching, patients with T2DM not prescribed statins were followed up until 2018 to estimate the incidence rates of coronary heart disease (CHD) and stroke. The efficacy of atorvastatin for the primary prevention of CV events in patients with T2DM was derived from a pivotal clinical trial. The outcome measures were the number of CV events prevented after the change in criteria and the consequent cost savings.

Results: In South Korea, the current and revised criteria covered 2,434,379 and 3,446,149 patients with T2DM, respectively. The change in criteria resulted in the prevention of 726 CV events and cost savings of US dollars (USD) 5.5 million at the national level and USD 0.0089 per member per month in the fifth year.

Conclusion: Easing the reimbursement criteria for statin treatment among patients with T2DM was associated with a reduction in CV events and their related costs; therefore, changing the reimbursement criteria is worth further consideration to mitigate the burden of CV disease.

Lipid cutoffs for increased cardiovascular disease risk in nondiabetic young people

AIMS

The relevance of blood lipid abnormalities to cardiovascular disease (CVD) risk in young populations is unclear. Here, we aimed to identify the cutoff levels of lipid parameters for increased risk of CVD among nondiabetic young adults aged 20-39 years.

METHODS

Using data from a nationally representative Korean National Health Insurance System database, we followed up 6,204,153 subjects who underwent health examinations between 2009 and 2012 until the end of 2018. The primary outcome was incident CVD, defined as a composite of myocardial infarction and stroke. We assessed the associations between pre-specified lipid levels and CVD risk. Subgroup analysis of the number of cardiovascular risk factors (obesity, hypertension, and current smoking) was also conducted.

RESULTS

During a median follow-up of 7.7 years, there were 14,569 (0.23%) cases of myocardial infarction, 9,459 (0.15%) cases of stroke, and 23,680 (0.38%) cases of composite CVD. Using total cholesterol (TC) level of <140 mg/dL, triglyceride (TG) level of <60 mg/dL, LDL-cholesterol level of <100 mg/dL, and non-HDL-cholesterol level of <130 mg/dL as reference groups, a significantly higher risk of CVD was observed in subjects with a TC level of ≥200 mg/dL, TG level of ≥60 mg/dL, LDL-cholesterol level of ≥130 mg/dL, or non-HDL-cholesterol level of ≥140 mg/dL. The cutoff levels of TC that had statistical significance for increased risk of CVD were 240, 220, and 200 mg/dL in subjects with 0, 1, or 2-3 risk factors, respectively.

CONCLUSIONS

Even modest increases in lipid levels were associated with increased risk of CVD in this nondiabetic young population. Our data provide potential criteria for stratifying CVD risk based on real-world evidence.

Proton Pump Inhibitors and Risk of Cardiovascular Disease: A Self-Controlled Case Series Study

INTRODUCTION

We investigated cardiovascular risk due to proton pump inhibitor (PPI) treatment using a self-controlled case series (SCCS) study design, a type of case-only design and an approach to overcome between-person confounding in which individuals act as their own control.

METHODS

We conducted an SCCS study using the National Health Insurance Service-Health Screening cohort in Korea (2002-2015). The cohort included 303,404 adult participants without prior cardiovascular events, who were followed up until December 2015. The primary outcome was a composite of stroke or myocardial infarction. The SCCS method estimated the age-adjusted incidence rate ratio between periods with and without exposure to PPI among patients with primary outcomes. As sensitivity analysis, conventional multivariable Cox proportional regression analyses were performed, which treated the exposure to PPI and H2 blocker during follow-up as time-dependent variables.

RESULTS

In the SCCS design, 10,952 (3.6%) patients with primary outcomes were included. There was no association between PPI exposure and primary outcome (incidence rate ratio 0.98, 95% confidence interval [CI] 0.89-1.09). In the time-dependent Cox regression analyses, both PPI (adjusted hazard ratio 1.36, 95% CI 1.24-1.49) and H2 blocker (adjusted hazard ratio 1.46, 95% CI 1.38-1.55) were associated with an increased risk of the primary outcome.

DISCUSSION

Negative findings in the SCCS design suggest that association between increased cardiovascular risk and PPI, frequently reported in prior observational studies, is likely due to residual confounding related to conditions with PPI treatment, rather than a true relationship.

Risk of Post-Myocardial Infarction Pneumonia with Proton Pump Inhibitors, H2 Receptor Antagonists and Mucoprotective Agents: A Retrospective Nationwide Cohort Study

Patients with myocardial infarction (MI) are at high risk of developing pneumonia. Proton pump inhibitors (PPI) and H2-receptor antagonists (H2RA) are commonly used acid-suppressive medications to the patients with MI for gastrointestinal (GI) protection, which may increase the risk for pneumonia. We evaluated whether PPI, H2RA, and mucoprotective agents without anti-acid properties increase the risk of post-MI pneumonia. We performed a retrospective cohort study based on the National Health Insurance Service—National Sample Cohort in Korea. The study included 3701 patients discharged with MI without prior history of pneumonia. During follow-up, treatments with PPI, H2RA, and mucoprotective agents were collected as time-dependent variables based on the prescription records. We performed multivariate time-dependent Cox regression analyses for the development of post-MI pneumonia. During the mean 4.85 ± 3.75 years follow-up, 999 participants developed pneumonia. In the multivariate analyses (adjusted hazard ratio; 95% confidence interval), the risk for pneumonia was significantly increased in treatment with PPI (2.25; 1.57–3.21) and H2RA (1.50; 1.16–1.93). Meanwhile, the risk for pneumonia was not increased in treatment with mucoprotective agents. When we evaluated GI bleeding event according to the medications as a secondary outcome analysis, mucoprotective agents were associated with increased GI bleeding risk, but PPI and H2RA were not. In the use of the GI medications in the treatment of patients with MI, the influence of these drugs on bleeding and pneumonia should be considered.

Low-Density Lipoprotein Cholesterol Level, Statin Use and Myocardial Infarction Risk in Young Adults

Objective

The consequences of blood lipid abnormalities for cardiovascular disease risk in young adults is unclear. Optimal lipid levels may also vary depending on whether a statin drug is taken. It aimed to determine whether the optimal lipid levels in young adults differ depending on statin use.

Methods

Using a nationally representative database from the Korean National Health Insurance System, 6,350,400 participants aged 20–39 years who underwent a health examination between 2009–2012 were followed through to 2018. The primary outcome was incident myocardial infarction (MI). We assessed the associations between prespecified lipid levels and MI risk according to statin use.

Results

Among participants not taking statins, low-density lipoprotein cholesterol (LDL-C) levels ≥120 mg/dL were significantly associated with MI risk (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.27–1.40) compared with statin nonusers with LDL-C <80 mg/dL. Statin users with LDL-C categories <80, 80–100, 100–120, and ≥120 mg/dL all had significantly higher MI risk compared with statin nonusers with LDL-C <80 mg/dL; these HRs (95% CIs) were 1.66 (1.39–1.99), 1.68 (1.36–2.09), 1.63 (1.31–2.02), and 2.32 (2.07–2.60), respectively.

Conclusion

Young adults taking statins have an increased MI risk compared with statin nonusers, even when they have similar LDL-C levels. Specific lipid targets may need to differ depending on statin use.

Risk of Periprosthetic Joint Infection in Patients With Total Knee Arthroplasty Undergoing Colonoscopy: A Nationwide Propensity Score Matched Study

BACKGROUND

The post-colonoscopy periprosthetic joint infection (PJI) risk in patients with total prosthetic knee joints has limited research. The present study investigated the PJI risk and determined the risk factors for post-colonoscopy PJI in total knee arthroplasty (TKA) recipients. The hypothesis was that colonoscopy is associated with an increased PJI risk in patients with total prosthetic knee joints. This study can potentially help guide the decision making for prophylactic antibiotic use for colonoscopy.

METHODS

This nationwide matched cohort study used claims data from the Health Insurance Review and Assessment Service database and enrolled patients who underwent unilateral TKA between 2008 and 2016. The history of diagnostic colonoscopy was investigated at least 1 year postoperatively. The propensity score was matched between colonoscopy and non-colonoscopy cohorts, and the post-colonoscopy PJI risk was compared. The PJI risk following invasive colonoscopic procedures, including biopsy, polypectomy, and mucosal or submucosal resection, was investigated, and the risk factors for post-colonoscopy PJI were determined.

RESULTS

In total, 45,612 and 211,841 patients were matched in the colonoscopy and control cohorts, respectively. The colonoscopy cohort had greater 9-month and 1-year PJI risks from the index colonoscopy date than the matched controls (9 months: hazard ratio [HR] 1.836, P = .006; 1 year: HR 1.822, P = .031). Invasive colonoscopic procedures did not increase the PJI risk at any time point post-colonoscopy. The only significant risk factor for PJI was post-traumatic arthritis (adjusted HR 4.034, P = .023).

CONCLUSION

Colonoscopy was associated with an increased PJI risk in TKA recipients, regardless of concomitant invasive colonoscopic procedures.

LEVEL OF EVIDENCE

III, Prognostic.

Ticagrelor versus prasugrel in patients with acute myocardial infarction

BACKGROUND

Ticagrelor and prasugrel are the mainstay of antithrombotic therapy for patients with acute myocardial infarction (MI). However, direct comparative data on clinical outcomes of potent P2Y12 inhibitors are limited, especially in East Asian populations. We aimed to evaluate the effect of ticagrelor versus prasugrel on clinical outcomes in patients with acute MI.

METHODS

From the Korean nationwide National Health Insurance database, 10,797 patients with acute MI who received either ticagrelor or prasugrel in combination with aspirin after percutaneous coronary intervention (PCI) were enrolled. The primary outcome was net clinical benefit, defined as a composite of death, MI, stroke, or major bleeding. Secondary outcomes included the individual components of the primary outcome as effectiveness and safety measures.

RESULTS

Among 10,797 patients, 9591 (88.8%) received ticagrelor and 1206 (11.2%) received prasugrel. During a median follow-up of 1.8 years, the primary outcome occurred in 1051 (16.6%) and 131 (14.4%) patients in the ticagrelor and prasugrel groups, respectively. In the propensity score matched cohort (n = 5979), the risk for the primary outcome was similar between the two groups (hazard ratio [HR] 0.949 for prasugrel; 95% confidence interval [CI]: 0.780-1.154). The risks for the composite of death, MI, or stroke (HR 0.938; 95% CI: 0.752-1.169) and major bleeding (HR 1.022; 95% CI: 0.709-1.472) were also comparable.

CONCLUSIONS

In patients with acute MI undergoing PCI, ticagrelor and prasugrel appeared to have similar net clinical benefits. The risks for death, MI, or stroke and major bleeding were not significantly different between the two groups.

Risk of Cardiovascular Events and Medical Cost of Dapagliflozin and Dipeptidyl Peptidase-4 Inhibitors

This study compared dapagliflozin, a sodium-glucose co-transporter 2 inhibitor, and dipeptidyl peptidase-4 inhibitors (DPP-4i) with regard to cardiovascular (CV) event incidence and direct medical costs during type 2 diabetes treatment. A retrospective cohort study was conducted using national health insurance claims data from September 1, 2014, to June 30, 2018, of patients in Korea. Patients who were prescribed dapagliflozin and DPP-4i for the first time were included. The primary outcome was the incidence of a composite of major adverse CV events (MACEs)—nonfatal myocardial infarction, nonfatal stroke, or in-hospital CV death. Proportional hazard models after propensity score weighting were used to determine hazard ratios (HRs) and 95% confidence intervals (CIs) for MACE in the dapagliflozin and DPP-4i groups. A decision analytic model was used to compare direct medical costs between the two treatment groups from a healthcare provider’s perspective. Of the 260,336 patients in the cohort, 23,147 and 237,189 received dapagliflozin and DPP-4i, respectively. During the follow-up, 184 patients receiving dapagliflozin and 3,674 receiving DPP-4i (incidence, 6.47 and 11.33 events/1,000 person-years, respectively) had MACE. The adjusted HR of MACE for dapagliflozin compared with that for DPP-4i was 0.69 (95% CI 0.57–0.83). The corresponding HRs were consistent among patients with and without underlying CV disease. The estimated direct medical cost appeared to be lower by $68,452 in the dapagliflozin group than that in the DPP-4i group for 3 years, in 1,000 hypothetical patients. In this population-based cohort study, the use of dapagliflozin instead of DPP-4i was associated with a reduced risk of MACE, which subsequently reduced direct medical costs. These data provide valuable information to patients, practitioners, and authorities regarding the risk of CV events associated with dapagliflozin versus DPP-4i use in clinical practice.

Statin initiation and all-cause mortality in incident statin-naïve dialysis patients

BACKGROUND AND AIMS

Cardiovascular disease is the main cause of death in end-stage kidney disease (ESKD) patients. We aimed to explore the association between statin initiation after starting dialysis and all-cause mortality in statin-naïve ESKD patients.

METHODS

We analyzed nationwide claims data of incident dialysis patients from 2010 to 2017 in South Korea. Patients who had previous cardiovascular events or were administered statins before dialysis were excluded. The study group included dialysis patients receiving statins within 1 year after dialysis initiation. The control group was organized after propensity-score matching with age, sex, time of dialysis initiation, and underlying diabetes mellitus and hypertension. The main outcomes were all-cause mortality and major cardiovascular events.

RESULTS

We included 1596 patients who started statin treatment and 1:1 matched statin-nonusers. During the 9438 person-year follow-up, 468 deaths and 264 major adverse cardiovascular events (MACEs) occurred. Statin initiation was associated with a reduced risk of all-cause mortality (adjusted hazard ratio (aHR) 0.72, 95% confidence interval (CI) 0.60-0.87, p = 0.001), but not with MACE incidence (aHR 1.06, 95% CI 0.83-1.36, p = 0.62). In particular, patients prescribed the recommended dosage of statins according to the Kidney Disease Improving Global Outcomes guidelines showed the lowest mortality risk (aHR 0.55, 95% CI 0.40-0.75, p < 0.001).

CONCLUSIONS

Statin initiation was associated with lower risk of all-cause mortality in statin-naïve ESKD patients. As indication bias may be present in observational study setting, further prospective studies are warranted to validate the association of statin initiation with mortality in incident dialysis cases.

Did inter-hospital transfer reduce mortality in patients with acute myocardial infarction in the real world? A nationwide patient cohort study

INTRODUCTION

Inter-hospital transfer (IHT) and primary percutaneous coronary intervention (PCI) are preferred over onsite thrombolysis when provided expeditiously. On the other hand, its benefit has not been evaluated in a real-world situation. This study examined the effects of IHT on the short- and long-term mortality in patients with acute myocardial infarction (AMI) and compared the reperfusion treatments and resources between the referring and receiving hospitals.

METHODS

Patients newly diagnosed with AMI and admitted to hospital were selected from the national health insurance database from 2004 to 2018. The 30-day and one-year mortality in the transferred and non-transferred patients were estimated and compared using stabilized inverse probability of treatment weighting to account for confounding bias.

RESULTS

Of the 258,291 participants, 10,158 were transferred to one or more hospitals. IHT was more likely to occur to older or more comorbid people, patients in rural areas, and those whose insurance was medical aid. The 30-day and one-year mortality of the non-IHT group was 9.7% and 15.8%, respectively, whereas the figure was 11.4% and 20.5% in the IHT group. After balancing the baseline characteristics, the transferred patients were 1.12 (95% CI: 1.06-1.20) and 1.25 (95% CI: 1.20-1.31) times more likely to die during the subsequent 30 days and one year, respectively, than those treated solely at the presenting hospital. In ST-segment elevation myocardial infarction (STEMI), the hazard ratios of the 30-day and 1-year mortality were 1.14 (95% CI: 0.97-1.35) and 1.31 (95% CI: 1.15-1.49) in the transferred patients after balancing cardiogenic shock and cardiac arrest. On-site thrombolysis was rarely performed in the referring hospitals.

CONCLUSION

Patients transferred for the treatment of AMI experienced higher short- and long-term mortality. Therefore, onsite thrombolysis and the estimated time delay to PCI should be considered in regional hospitals to reduce mortality with the organization of STEMI treatment networks.

Clinical Study Using Healthcare Claims Database

The healthcare claims database is a database created using claims data accumulated while operating the government's health insurance system. The National Health Insurance Service (NHIS) provides benefits for health promotion, prevention, diagnosis, and disease and injury treatment, as well as for rehabilitation, birth, and death. Ninety-seven percent of the total population is enrolled in the NHIS; individuals pay a monthly insurance contribution to the system, and the NHIS pays a portion of the cost of reimbursement items to the medical institution when the subscriber receives medical services. In this process, the NHIS and Health Insurance Review Agency (HIRA) decide on payment, and claims data are documented items that medical institutions claim to these government agencies. The NHIS and HIRA have established a database to support policy and academic research, and they provide this database to researchers. Health claims data are representative of the nation, reflecting the actual medical environment. They also shorten the time and cost required for research and have several advantages as research data. However, studies should be conducted with an understanding of the limitations of claims data, a sufficient understanding of the characteristics of the Korean insurance system, and criteria for providing reimbursed services. Moreover, validating the healthcare claims database will facilitate more useful and reliable research.

Epidemiology of cardiovascular disease and its risk factors in Korea

Cardiovascular disease (CVD) is the leading cause of death and a major contributor to disability worldwide. Currently, Korea is among countries with the lowest CVD mortality rates, and the age-adjusted CVD mortality rate is still decreasing. However, depending on the CVD type, the mortality and incidence trends vary. Without age-standardization, cerebrovascular disease mortality peaked in 1994 (82.1 per 100K) and continued to decline until 2018 (44.7 per 100K), while heart disease mortality recorded the lowest level in 2001 (44.9 per 100K) then increased again until 2018 (74.5 per 100K). Age-standardized mortality rates showed different trends: both cerebrovascular disease and heart disease mortality rates have declined over the past few decades, although the rate of decline varies. Based on the National Health Insurance claim database, the numbers of hospitalization for cerebrovascular disease and ischemic heart disease are increasing, but the age-standardized hospitalization rates are decreasing. Unlike other types of CVDs, heart failure is rapidly increasing in both mortality and hospitalization rates regardless of age-standardization. Seventy percent of Korean adults have at least one risk factor, 41% have ≥ 2 risk factors, and 19% have ≥ 3 risk factors including hypertension, diabetes, hypercholesterolemia, obesity, and smoking. Exposure to multiple risk factors increases with age, with 65% of senior citizens over 70 having ≥ 2 risk factors and 34% having ≥ 3 risk factors. As the elderly population, especially those with multiple risk factors and chronic disorders, is increasing, the management of this high-risk group will be an important challenge to prevent CVD in Korea.

Effect of Moderately but Persistently Elevated Lipid Levels on Risks of Stroke and Myocardial Infarction in Young Korean Adults

Background

Identifying predictive markers for future atherosclerotic cardiovascular diseases may be helpful to motivate young adults to promote healthy lifestyle. We sought to determine the association between persistently elevated low‐density lipoprotein‐cholesterol (LDL‐C) and/or triglyceride levels and the atherosclerotic cardiovascular diseases risks in young adults.

Methods and Results

We conducted a nationwide population‐based cohort study of 1 887 853 statin‐naive adults aged 20 to 39 years, with LDL‐C <190 mg/dL, using the Korean National Health Insurance Service database. Persistently elevated LDL‐C and triglyceride levels were defined by ≥3 measurements of ≥160 and ≥175 mg/dL, respectively. The primary outcome was a composite of stroke and myocardial infarction. Among the study population, 11 121 (0.59%) and 167 373 (8.87%) had persistently elevated LDL‐C and triglycerides, respectively. During a median follow‐up of 5.2 years, 2170 and 1537 incidences of stroke (0.16%) and myocardial infarction (0.23%) occurred. Persistently elevated LDL‐C levels were significantly associated with increased risks of the primary outcome, with an adjusted hazard ratio (HR) of 1.396 (95% CI, 1.005–1.940). This association was independent of high‐density lipoprotein cholesterol. Persistently elevated triglycerides were significantly associated with increased risks of the primary outcome (HR, 1.120; 95% CI, 1.015–1.236), but attenuated after adjustment for high‐density lipoprotein cholesterol.

Conclusions

Persistently elevated LDL‐C and triglyceride levels were associated with atherosclerotic cardiovascular diseases risk in young Korean adults without severe hypercholesterolemia. These lipid abnormalities should be considered risk factors in young adults since their effects on lifetime atherosclerotic cardiovascular diseases risk may become more pronounced over the life course.

Association between longitudinal blood pressure and prognosis after treatment of cerebral aneurysm: A nationwide population-based cohort study

BACKGROUND

High blood pressure is a major risk factor for the development and rupture of cerebral aneurysm. Endovascular coil embolization and surgical clipping are established procedures to treat cerebral aneurysm. However, longitudinal data of blood pressure after the treatment of cerebral aneurysm and its impact on long-term prognosis are not well known.

METHODS

This retrospective cohort study included 1275 patients who underwent endovascular coil embolization (n = 558) or surgical clipping (n = 717) of cerebral aneurysm in 2002-2015 using the nationwide health screening database of Korea. Systolic and diastolic blood pressure of patients were repeatedly obtained from the nationwide health screening program. We performed a multivariate time-dependent Cox regression analysis of the primary composite outcome of stroke, myocardial infarction, and all-cause death.

RESULTS

During the mean follow-up period of 6.13 ± 3.41 years, 89 patients suffered the primary outcome. Among the total 3546 times of blood pressure measurement, uncontrolled high blood pressure (systolic ≥140 mmHg or diastolic ≥90 mmHg) was 22.9%. There was a significantly increased risk of primary outcome with high systolic (adjusted HR [95% CI] per 10 mmHg, 1.16 [1.01-1.35]) and diastolic (adjusted HR [95% CI] per 10 mmHg, 1.32 [1.06-1.64]) blood pressure.

CONCLUSIONS

High blood pressure is prevalent even in patients who received treatment for cerebral aneurysm, which is significantly associated with poor outcome. Strict control of high blood pressure may further improve the prognosis of patients with cerebral aneurysm.

Cardiovascular risks of periodontitis and oral hygiene indicators in patients with diabetes mellitus

AIM

Periodontitis is a common chronic inflammatory disease prevalent in diabetes. The aim of this study was to evaluate periodontitis and poor oral hygiene as independent risk factors for either cerebral or myocardial infarction in the diabetes population.

METHODS

This retrospective cohort study included 17,009 patients with diabetes who had participated in a nationwide health-screening programme, including oral health examination, during 2002-2003 in South Korea. Presence of periodontitis, tooth loss and carious teeth were assessed by professional dentists, and the number of tooth brushings per day was evaluated through self-reported questionnaires. The primary study outcome was the development of cerebral or myocardial infarction, based on International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) codes, up to 31 December 2015.

RESULTS

The study enrolled 17,009 patients with diabetes. Over the mean 11.64 years of follow-up, 1341 patients presented with either cerebral or myocardial infarction. On multivariable Cox proportional hazards regression analysis, presence of periodontitis was an independent risk factor for either cerebral or myocardial infarction [adjusted hazard ratio (HR): 1.17, 95% confidence interval (CI): 1.02-1.34; P = 0.030]. An increased number of carious teeth (≥5) was also associated with risk of cerebral or myocardial infarction (adjusted HR: 1.67, 95% CI: 1.20-2.32; P = 0.002), whereas frequent tooth brushing (≥2 times/day) was negatively associated with risk of cerebral or myocardial infarction (adjusted HR: 0.79, 95% CI: 0.70-0.90; P < 0.001) compared with tooth brushing ≤1 time/day.

CONCLUSION

Early identification and intervention of periodontal disease may be effective in reducing cardiovascular complications in the diabetes population, and improved oral hygiene would probably be associated with lower cardiovascular risk in diabetes.

Risk of a complete exchange or failure in total knee arthroplasty and unicompartmental knee arthroplasty: a nationwide population-based cohort study from South Korea

PURPOSE

Few large-scale studies using adjusted data from national registries have explored the risk factors of subsequent revision in patients with unicompartmental knee arthroplasty (UKA) compared to those with total knee arthroplasty (TKA). We investigated the incidence rate and risk factors of subsequent revision in patients with UKA and TKA.

METHODS

We enrolled all patients who had undergone TKA or UKA as the primary surgical procedure without histories of having undergone either procedure during the preceding 2 years. Matched Cox regression models were used to compare the risks of revision between groups after propensity score matching. Revision was defined as conversion to revision TKA after primary TKA and conversion to TKA after UKA.

RESULTS

The study enrolled 418,806 TKA patients and 446,009 UKA patients. The risk of revision during the entire study period was higher for patients with UKA than for patients with TKA (adjusted hazard ratio [HR] 1.22, 95% confidence interval [95% CI]: 1.10-1.36). The Kaplan-Meier 8-year survival was 98.7% in the TKA group and 96.7% in the UKA group. Patients with UKA were at an increased risk of revision in cases of advanced age (70-79 years, HR 1.40, 95% CI: 1.15-1.71), female sex (HR 1.32, 95% CI: 1.16-1.49), the presence of chronic obstructive pulmonary disease (COPD) (HR 1.27, 95% CI: 1.05-1.54), the presence of peptic ulcer disease (PUD) (HR 1.34, 95% CI: 1.11-1.61) compared to patients with TKA. In patients with hemiplegia, however, UKA were associated with a lower risk of subsequent revision (HR 0.25, 95% CI: 0.07-0.94).

CONCLUSION

The risk of a complete exchange or failure was higher for patients with UKA than for patients with TKA. The most significant independent risk factors for subsequent a complete exchange or failure in patients with UKA were advanced age (70-79 years), female sex, and the presence of comorbidities such as COPD and PUD.

Association between physical activity and subsequent cardiovascular disease among 5-year breast cancer survivors

PURPOSE

To examine the association of physical activity among long-term breast cancer survivors on the occurrence of subsequent cardiovascular disease (CVD).

METHODS

We investigated the risk of CVD among 39,775 breast cancer patients who were newly diagnosed in 2006 and survived until 2011 within the Korean National Health Insurance Service database. Patients were followed up from 5 years after breast cancer diagnosis to the date of CVD event, death, or December 31, 2018, whichever came earliest. Every 500 MET-mins/week correspond to 152, 125, and 62.5 min per week of light-, moderate-, and vigorous-intensity physical activity, respectively. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for CVD were calculated using Cox proportional hazards regression by physical activity levels.

RESULTS

Compared with those with physical activity of 0 MET-min/week, those with 1-499 (aHR 0.82, 95% CI 0.69-0.98), 500-999 (aHR 0.75, 95% CI 0.63-0.90), and ≥ 1,000 (aHR 0.76, 95% CI 0.63-0.93) MET-min/week of PA had lower risk of CVD. Higher levels of PA were associated with lower risk of stroke (p for trend = 0.016). The benefits of PA on obese and overweight breast cancer survivors were smaller than those in normal weight survivors. The frequency of moderate-to-vigorous physical activity (MVPA) showed a reverse J-curve association with CVD, and the best benefit occurred in the 3-4 times MVPA per week group (aHR 0.59, 95% CI 0.46-0.74).

CONCLUSIONS

The study showed that even small amounts of PA may be beneficial in potentially decreasing the risk of CVD, CHD, and stroke in breast cancer survivors. Our result will be useful to prescribe and delivery exercise among long-term breast cancer survivors.

Impact of Dyslipidemia on the Risk of Second Cancer in Thyroid Cancer Patients: A Korean National Cohort Study

BACKGROUND

Studies have shown that radioactive iodine therapy (RAIT) affects the development of second cancer in thyroid cancer patients. The impact of other factors, such as dyslipidemia are not clear.

METHODS

A retrospective analysis of thyroid cancer patients with a 1,251,913 person-year follow-up was conducted using data from the Health Insurance Review and Assessment database in South Korea from January 2008 to December 2018. We investigated factors related to second cancer development using a nested case-control analysis to avoid length bias.

RESULTS

The overall risk of developing second cancer was higher in thyroid cancer patients than in the general population [standardized incidence ratio, 3.34; 95% confidence interval (CI) 3.30-3.39]. Second cancer incidence was higher in patients who received RAIT than in those who did not [odds ratio (OR) 1.130; 95% CI 1.094-1.169]. Moreover, the risk of second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.265; 95% CI 1.223-1.309). After adjustment for RAIT, the incidence of a second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.262; 95% CI 1.221-1.306).

CONCLUSIONS

The risk of second cancer development in patients with thyroid cancer appears to be high. Dyslipidemia may be associated with an increased risk of several types of second cancers.

Cardiovascular and Bleeding Risks Associated With Nonsteroidal Anti-Inflammatory Drugs After Myocardial Infarction

BACKGROUND

Limited data are available regarding the risk for adverse clinical events with concomitant nonsteroidal anti-inflammatory drug (NSAID) treatment after myocardial infarction (MI).

OBJECTIVES

The aim of this study was to investigate the risk for cardiovascular and bleeding events according to groups of antithrombotic medications and subtypes of NSAIDs in patients with MI.

METHODS

This was a nationwide cohort study to enroll a study population from the Health Insurance Review and Assessment Service database in Korea between 2009 and 2013. Patients were divided into groups on the basis of the prescribed antithrombotic medications. The primary and secondary outcomes were thromboembolic cardiovascular and clinically relevant bleeding events. The risk for adverse clinical events was assessed by ongoing NSAID treatment and subtypes of NSAIDs.

RESULTS

In total, 108,232 patients (mean age 64.2 ± 12.8 years, 72.1% men, mean follow-up duration 2.3 ± 1.8 years) with first diagnosed MI were enrolled. Concomitant NSAID treatment significantly increased the risk for cardiovascular events (hazard ratio [HR]: 6.96; 95% confidence interval [CI]: 6.24 to 6.77; p < 0.001) and bleeding events (HR: 4.08; 95% CI: 3.51 to 4.73; p < 0.001) compared with no NSAID treatment. Among NSAID subtypes, the risk for cardiovascular and bleeding events was lowest with the use of celecoxib (HR: 4.65; 95% CI: 3.17 to 6.82; p < 0.001, and 3.44; 95% CI: 2.20 to 5.39; p < 0.001, respectively) and meloxicam (HR: 3.03; 95% CI: 1.68 to 5.47; p < 0.001, and 2.80; 95% CI: 1.40 to 5.60; p < 0.001, respectively).

CONCLUSIONS

Concomitant NSAID treatment significantly increased the risk for cardiovascular and bleeding events after MI. Although NSAID treatment should be avoided after MI, celecoxib and meloxicam could be considered as alternative options in cases in which NSAID use is unavoidable.

Five-Year Risk of Acute Myocardial Infarction After Acute Ischemic Stroke in Korea

Background The long-term incidence of acute myocardial infarction (AMI) in patients with acute ischemic stroke (AIS) has not been well defined in large cohort studies of various race-ethnic groups. Methods and Results A prospective cohort of patients with AIS who were registered in a multicenter nationwide stroke registry (CRCS-K [Clinical Research Collaboration for Stroke in Korea] registry) was followed up for the occurrence of AMI through a linkage with the National Health Insurance Service claims database. The 5-year cumulative incidence and annual risk were estimated according to predefined demographic subgroups, stroke subtypes, a history of coronary heart disease (CHD), and known risk factors of CHD. A total of 11 720 patients with AIS were studied. The 5-year cumulative incidence of AMI was 2.0%. The annual risk was highest in the first year after the index event (1.1%), followed by a much lower annual risk in the second to fifth years (between 0.16% and 0.27%). Among subgroups, annual risk in the first year was highest in those with a history of CHD (4.1%) compared with those without a history of CHD (0.8%). The small-vessel occlusion subtype had a much lower incidence (0.8%) compared with large-vessel occlusion (2.2%) or cardioembolism (2.4%) subtypes. In the multivariable analysis, history of CHD (hazard ratio, 2.84; 95% CI, 2.01-3.93) was the strongest independent predictor of AMI after AIS. Conclusions The incidence of AMI after AIS in South Korea was relatively low and unexpectedly highest during the first year after stroke. CHD was the most substantial risk factor for AMI after stroke and conferred an approximate 5-fold greater risk.

Real-World Bleeding and Ischemic Events in Asian Patients on P2Y12-Inhibitors After Percutaneous Coronary Intervention: A National Claims Data Analysis

Introduction

The safety and effectiveness of potent P2Y12 inhibitors in East Asians have been questioned because of the higher bleeding tendency and lower thrombotic risk in this population. We comparatively evaluated the safety, effectiveness and treatment persistence of the dual antiplatelet therapies (DAPT) with clopidogrel (CDAPT), ticagrelor (TDAPT) and prasugrel (PDAPT) after percutaneous coronary intervention (PCI) in the Korean population.

Methods

A retrospective cohort study was conducted using Korean National Health Insurance claims data. In 57,197 patients treated with DAPT after PCI, the risk of bleeding events, risk of major adverse cardiac and cerebral events (MACCE: a composite of all-cause death, myocardial infarction [MI], stroke and revascularization), risk of net adverse clinical events (NACE) and persistence and adherence rates were assessed with stabilized inverse probability of treatment weighting.

Results

TDAPT was associated with higher risks of bleeding (1 year: hazard ratio [HR], 1.37; 95% confidence interval [CI] 1.28–1.46; prolonged: HR 1.39, 95% CI 1.31–1.47), MACCE (1 year: HR 1.10, 95% CI 1.03–1.18; prolonged: HR 1.24, 95% CI 1.16–1.31) and NACE (1 year: HR 1.23, 95% CI 1.18–1.29; prolonged: HR 1.31, 95% CI 1.25–1.36) than CDAPT both at 1 year and in the prolonged periods, whereas there were no significant differences between PDAPT and CDAPT. Similar results were also observed in a subgroup analysis of patients with baseline MI. CDAPT was associated with higher persistence and adherence rates than TDAPT and PDAPT.

Conclusions

CDAPT was associated with clinical outcomes that were more favorable than those in TDAPT and comparable to those in PDAPT and drug persistence and adherence that were higher than in TDAPT or PDAPT. Clopidogrel may remain a viable first option for post-PCI DAPT in East Asian patients with a low thrombotic risk and a high bleeding tendency.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01526-4) contains supplementary material, which is available to authorized users.

Real-world data analysis of the clinical and economic burden and risk factors in patients with major depressive disorder with an inadequate response to initial antidepressants

AIM

We aimed to determine the incidence of and identify the factors associated with treatment-resistant depression (TRD), psychiatric conditions, hospitalization, and cost in patients with major depressive disorder (MDD) who were treated using second-line strategies after an inadequate response to initial antidepressants (AD).

MATERIALS AND METHODS

Using South Korean National Health Insurance claims data (1 January 2013 to 30 June 2018), we conducted a retrospective cohort analysis in newly treated patients with MDD who subsequently switched or added AD, or added atypical antipsychotics (AAPs) as a second-line treatment. We assessed the incidence of treatment-resistant depression (TRD), psychiatric conditions, and hospitalization for the first 2 years and costs in the third year. Odds ratios (ORs) or relative ratios were estimated using logistic and linear regression models to identify the risk factors for clinical and economic outcomes.

RESULTS

In 15,887 patients, the TRD was 16.81% during the 24-month follow-up period (14.14% in switching AD, 19.65% in adding AD, and 19.91% in adding AAP; p < 0.0001). When adding AD or AAP, the OR of TRD was 1.43 (95% confidence interval (CI): 1.30-1.56) and 1.42 (95% CI: 1.23-1.65), respectively, compared to switching AD. However, these factors were not associated with the incidence of psychiatric conditions. Adding AAP increased hospitalization (OR = 1.25, 95% CI: 1.11-1.41), the number of inpatient days by 2.57-fold (95% CI: 1.75-3.76), and cost by 1.20-fold (95% CI: 1.02-1.40), compared to switching AD; adding AD did not show a significant association with these outcomes.

CONCLUSIONS

In patients with MDD with inadequate responses to initial AD, TRD still occurred after subsequent treatments according to clinical guidelines. Since the effectiveness of second treatment strategies can differ in reality, further analysis of the clinical and economic evidence regarding second treatment strategies, such as adding AD or AAP, is needed using real-world data.

Association between oseltamivir use and neuropsychiatric adverse events in influenza patients: a nationwide population-based cohort study

Background: A potential risk of neuropsychiatric adverse events (NPAEs) of oseltamivir has remained controversial by retrospective cohort studies. This nationwide population-based cohort study aimed to assess the risk of NPAEs in influenza patients undergoing oseltamivir treatment (users) compared with a propensity score-matched cohort of patients not receiving oseltamivir (non-users). Research design and methods: Using the Korean National Health Service-Sample Cohort Database, patients diagnosed with incident influenza during 2003-2013 were divided into two cohorts: oseltamivir users and non-users. We calculated adjusted hazard ratios (aHRs) for the 5-day treatment course with oseltamivir using Cox regression analysis. Results: The incidence rate of NPAEs during 5-day oseltamivir treatment was 0.0029 and 0.0023 in oseltamivir users and non-users, respectively. The risk of NPAEs was different according to age, with an increased risk in patients aged 10-19 years (aHR 2.69, 95% CI 1.05-6.93) and a decreased risk in patients aged 0-9 years (aHR 0.46, 95% CI 0.24-0.88). The non-significant positive associations were observed in patients aged 20-64 years and those aged greater than 65 years. Conclusions: Although the reason for the inverse association in children aged 0-9 years is unknown, oseltamivir could increase the risk of NPAEs for children or adolescents aged greater than 10 years.

Cost-Effectiveness of Tiotropium in Elderly Patients with Severe Asthma Using Real-World Data

BACKGROUND

Tiotropium has the potential to alleviate asthmatic symptoms caused by the aging of lungs. However, few studies have focused on specific treatments for elderly patients with asthma.

OBJECTIVES

To estimate the cost-effectiveness of adding tiotropium to inhaled corticosteroids and long-acting beta-agonists in elderly patients with severe asthma using real-world data.

METHODS

Phase I was a retrospective cohort study using the National Health Insurance claims data to measure clinical and economic outcomes. In phase II, a Markov model was constructed to evaluate cost-effectiveness from Korean health care system perspective, based on phase I, including 2 health states, and an asthma exacerbation event. We estimated cost given in 2018 US dollars, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio. Subgroup analyses for patients with poorly controlled symptoms (frequent short-acting beta-agonist users; frequent exacerbators) were performed.

RESULTS

In elderly patients with severe asthma, the incremental cost and effectiveness in the tiotropium group compared with the inhaled corticosteroid and long-acting beta-agonist group were $2281 and 0.038 QALYs, respectively. The incremental cost-effectiveness ratio was $60,074/QALY, indicating that the addition of tiotropium is not a cost-effective alternative. Meanwhile, 2 subgroups with poorly controlled symptoms showed that adding tiotropium is a cost-effective alternative (frequent short-acting beta-agonist users $4078/QALY; frequent exacerbators $8332/QALY).

CONCLUSIONS

Tiotropium shows a higher cost-effectiveness profile when applied to elderly patients with uncontrolled symptoms. These results using real-world evidence provide information beyond the clinical outcomes reported by randomized controlled trials, providing a complementary ground in establishing the reimbursement criteria of tiotropium for elderly patients with severe asthma.