Comparison of Factors Associated With Direct Versus Transferred-in Admission to Government-Designated Regional Centers Between Acute Ischemic Stroke and Myocardial Infarction in Korea.

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

Augmentation index is associated with coronary revascularization in patients with high Framingham risk scores: a hospital-based observational study.

BACKGROUND: This study analyzed PWAs in patients with high Framingham risk scores to determine whether PWA is predictive of coronary artery disease (CAD) severity and percutaneous coronary intervention (PCI) treatment. METHODS: In total, 310 patients were screened due to suspected CAD; 78 were excluded due to PCI history (32), atrial fibrillation (11), or acute myocardial infarction (35). The augmentation index (AIx) was analyzed immediately before coronary angiography. PCI was performed in 73 (31.5 %) patients. RESULTS: The mean AIx, adjusted by heart rate (AIx@75) was different for each clinical diagnosis in the PCI group (stable angina, 30.6 ± 7.7 %; silent ischemia, 30.2 ± 8.6 %; unstable angina, 38.5 ± 8.5 %; p = 0.026). The 10-year estimate of CVD risk, based on the Framingham heart score, was 25.3 ± 6.5 % and the mean AIx@75 was 31.6 ± 8.5 % in the PCI group, significantly higher than in the non-PCI group (18.8 ± 10.2 %, p < 0.001; 27.2 ± 9.0 %, p = 0.006, respectively). An inverse correlation was observed between the minimal luminal area and AIx@75 (rho = -0.559, p = 0.010, n = 20). In ROC curve analysis of multivariate logistic regression model, higher HDL, medication of hypertension, and higher body mass index were associated with non-PCI and higher AIx@75 was associated with PCI (area under the curve, 0.764; 95 % CI: 0.701 to 0.819, z = 8.005; p <0.001). CONCLUSIONS: The AIx@75 seemed to reflect the clinical severity of CAD and was associated with PCI in patients with a high Framingham risk score.

Risk Factors for Major Lower Limb Amputation and Effect of Endovascular Revascularization in Patients with Diabetic Foot Wound.

Objective: Major lower extremity amputation (LEA) such as below-knee or above-knee amputations can result in more physical disabilities and poorer socioeconomic functions than minor LEAs in diabetic foot ulcer (DFU). Therefore, identification of risk factors for major LEA and investigation of effectiveness of endovascular revascularization are critical for prevention and better prognosis of DFU patients. Methods: From January 2014 to December 2017, a total of 125 patients with DFU treated with any level of amputation were included in this study. Demographic, diabetes-related, DFU-related and -relevant laboratory information were investigated to predict major amputation. To identify risk factors for major amputation, logistic regression analysis was performed for each variable. The effectiveness of endovascular revascularization treatment was analyzed using Kaplan-Meier survival curves. Results: Major amputation was performed for 22 of 125 patients. Multivariate logistic regression analysis indicated that DM duration, peripheral arterial occlusive disease (PAOD) previous amputation, abscess, Wagner grade, CRP and albumin were significant risk factors for major amputation in DFU patients. PAOD was the most important risk factor. Major amputation-free survival rate at 5 years was 97.4% in a non-PAOD group, 58.3% in a PAOD without revascularization group, and 88.0% in a PAOD with revascularization group, showing statistically significant differences among them. Conclusion: The duration of DM, PAOD, previous amputation, abscess, Wagner grade, CRP and albumin were major risk factors for major LEA in DFU patients. The most valuable and critical finding was that revascularization in diabetic foot patients with PAOD significantly improved major amputation-free survival rates.

A Novel Method for Angiographic Contrast-Based Diagnosis of Stenosis in Coronary Artery Disease: In Vivo and In Vitro Analyses.

BACKGROUND: The existing diagnostic methods for coronary artery disease (CAD), such as coronary angiography and fractional flow reserve (FFR), have limitations regarding their invasiveness, cost, and discomfort. We explored a novel diagnostic approach, coronary contrast intensity analysis (CCIA), and conducted a comparative analysis between it and FFR. METHODS: We used an in vitro coronary-circulation-mimicking system with nine stenosis models representing various stenosis lengths (6, 18, and 30 mm) and degrees (30%, 50%, and 70%). The angiographic brightness values were analyzed for CCIA. The in vivo experiments included 15 patients with a normal sinus rhythm. Coronary angiography was performed, and arterial movement was tracked, enabling CCIA derivation. The CCIA values were compared with the FFR (n = 15) and instantaneous wave-free ratio (iFR; n = 11) measurements. RESULTS: In vitro FFR showed a consistent trend related to the length and severity of stenosis. The CCIA was related to stenosis but had a weaker correlation with length, except for with 70% stenosis (6 mm: 0.82 ± 0.007, 0.68 ± 0.007, 0.61 ± 0.004; 18 mm: 0.78 ± 0.052, 0.69 ± 0.025, 0.44 ± 0.016; 30 mm: 0.80 ± 0.018, 0.64 ± 0.006, 0.40 ± 0.026 at 30%, 50%, and 70%, respectively). In vitro CCIA and FFR were significantly correlated (R = 0.9442, p < 0.01). The in vivo analysis revealed significant correlations between CCIA and FFR (R = 0.5775, p < 0.05) and the iFR (n = 11, R = 0.7578, p < 0.01). CONCLUSIONS: CCIA is a promising alternative for diagnosing stenosis in patients with CAD. The initial in vitro validation and in vivo confirmation in patients demonstrate the feasibility of applying CCIA during coronary angiography. Further clinical studies are warranted to fully evaluate the diagnostic accuracy and potential impact of CCIA on CAD management.

Impact of cardiac rehabilitation on ventricular-arterial coupling and left ventricular function in patients with acute myocardial infarction.

To maintain efficient myocardial function, optimal coordination between ventricular contraction and the arterial system is required. Exercise-based cardiac rehabilitation (CR) has been demonstrated to improve left ventricular (LV) function. This study aimed to investigate the impact of CR on ventricular-arterial coupling (VAC) and its components, as well as their associations with changes in LV function in patients with acute myocardial infarction (AMI) and preserved or mildly reduced ejection fraction (EF). Effective arterial elastance (EA) and index (EAI) were calculated from the stroke volume and brachial systolic blood pressure. Effective LV end-systolic elastance (ELV) and index (ELVI) were obtained using the single-beat method. The characteristic impedance (Zc) of the aortic root was calculated after Fourier transformation of both aortic pressure and flow waveforms. Pulse wave separation analysis was performed to obtain the reflection magnitude (RM). An exercise-based, outpatient cardiac rehabilitation (CR) program was administered for up to 6 months. Twenty-nine patients were studied. However, eight patients declined to participate in the CR program and were subsequently classified as the non-CR group. At baseline, E' velocity showed significant associations with EAI (beta -0.393; P = 0.027) and VAC (beta -0.375; P = 0.037). There were also significant associations of LV global longitudinal strain (LV GLS) with EAI (beta 0.467; P = 0.011). Follow-up studies after a minimum of 6 months demonstrated a significant increase in E' velocity (P = 0.035), improved EF (P = 0.010), and LV GLS (P = 0.001), and a decreased EAI (P = 0.025) only in the CR group. Changes in E' velocity were significantly associated with changes in EAI (beta -0.424; P = 0.033). Increased aortic afterload and VA mismatch were associated with a negative impact on both LV diastolic and systolic function. The outpatient CR program effectively decreased aortic afterload and improved LV diastolic and systolic dysfunction in patients with AMI and preserved or mildly reduced EF.

Impact of angiotensin-converting enzyme inhibitors versus angiotensin receptor blockers on clinical outcomes in hypertensive patients with acute myocardial infarction.

There has been a concern that angiotensin receptor blockers (ARB) may increase myocardial infarction (MI) in hypertensive patients compared with other classes of anti-hypertensive drugs. Angiotensin-converting enzyme inhibitor (ACEI) is recommended as a first-line inhibitor of renin-angiotensin system (RASI) in patients with acute MI (AMI), but ARB is also frequently used to control blood pressure. This study investigated the association of ARB vs. ACEI with the long-term clinical outcomes in hypertensive patients with AMI. Among patients enrolled in the nationwide AMI database of South Korea, the KAMIR-NIH, 4,827 hypertensive patients, who survived the initial attack and were taking ARB or ACEI at discharge, were selected for this study. ARB therapy was associated with higher incidence of 2-year major adverse cardiac events, cardiac death, all-cause death, MI than ACEI therapy in entire cohort. After propensity score-matching, ARB therapy was still associated with higher incidence of 2-year cardiac death (hazard ratio [HR], 1.60; 95% confidence interval [CI], 1.20-2.14; P = 0.001), all-cause death (HR, 1.81; 95% CI, 1.44-2.28; P < 0.001), and MI (HR, 1.76; 95% CI, 1.25-2.46; P = 0.001) than the ACEI therapy. It was concluded that ARB therapy at discharge in hypertensive patients with AMI was inferior to ACEI therapy with regard to the incidence of CD, all-cause death, and MI at 2-year. These data suggested that ACEI be a more appropriate RASI than ARB to control BP in hypertensive patients with AMI.

Association of the medical therapy with beta-blockers or inhibitors of renin-angiotensin system with clinical outcomes in patients with mildly reduced left ventricular ejection fraction after acute myocardial infarction.

In the era of the initial optimal interventional and medical therapy for acute myocardial infarction (AMI), a number of patients with mildly reduced left ventricular ejection fraction (EF) (41%-49%) have been increasing. This observational study aimed to investigate the association between the medical therapy with oral beta-blockers or inhibitors of renin-angiotensin system (RAS) and 2-year clinical outcomes in patients with mildly reduced EF after AMI. Among patients enrolled in the Korea Acute Myocardial Infarction Registry-National Institute of Health, propensity-score matched patients who survived the initial attack and had mildly reduced EF were selected according to beta-blocker or RAS inhibitor therapy at discharge. Beta-blocker therapy at discharge was associated with lower 2-year major adverse cardiac events which was a composite of cardiac death, myocardial infarction, revascularization and re-hospitalization due to heart failure (8.7 vs 12.8/100 patient-years; hazard ratio [HR] 0.68; 95% confidence interval [CI] 0.50-0.93; P = .015), and no significant interaction between EF ≤ 45% and > 45% was observed (Pinteraction = 0.354). This association was mainly driven by lower myocardial infarction in patients with beta-blockers (HR 0.50; 95% CI 0.26-0.95; P = .035). Inhibitors of RAS at discharge were associated with lower re-hospitalization due to heart failure (1.8 vs 3.5/100 patient-years; HR 0.53; 95% CI 0.33-0.86; P = .010) without a significant interaction between EF ≤ 45% and > 45% (Pinteraction = 0.333). In patients with mildly reduced EF after AMI, the medical therapy with beta-blockers or RAS inhibitors at discharge was associated with better 2-year clinical outcomes.

Comparisons of Prehospital Delay and Related Factors Between Acute Ischemic Stroke and Acute Myocardial Infarction.

Background Prehospital delay is an important contributor to poor outcomes in both acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We aimed to compare the prehospital delay and related factors between AIS and AMI. Methods and Results We identified patients with AIS and AMI who were admitted to the 11 Korean Regional Cardiocerebrovascular Centers via the emergency room between July 2016 and December 2018. Delayed arrival was defined as a prehospital delay of >3 hours, and the generalized linear mixed-effects model was applied to explore the effects of potential predictors on delayed arrival. This study included 17 895 and 8322 patients with AIS and AMI, respectively. The median value of prehospital delay was 6.05 hours in AIS and 3.00 hours in AMI. The use of emergency medical services was the key determinant of delayed arrival in both groups. Previous history, 1-person household, weekday presentation, and interhospital transfer had higher odds of delayed arrival in both groups. Age and sex had no or minimal effects on delayed arrival in AIS; however, age and female sex were associated with higher odds of delayed arrival in AMI. More severe symptoms had lower odds of delayed arrival in AIS, whereas no significant effect was observed in AMI. Off-hour presentation had higher and prehospital awareness had lower odds of delayed arrival; however, the magnitude of their effects differed quantitatively between AIS and AMI. Conclusions The effects of some nonmodifiable and modifiable factors on prehospital delay differed between AIS and AMI. A differentiated strategy might be required to reduce prehospital delay.

Association of changes of pulse wave velocity and augmentation index after isometric handgrip exercise with coronary lesion extent and revascularization.

BACKGROUND: Arterial stiffness is associated with myocardial ischemia and incident coronary artery disease (CAD), and indexes of arterial stiffness are usually increased in patients with CAD. However, these indexes are often increased in elderly without CAD. Arterial stiffness in patients with CAD may become more evident after isometric handgrip exercise which increases systolic pressure and ventricular afterload. We investigated the association of the change of stiffness indexes after isometric handgrip exercise with the lesion extent of CAD and the necessity for coronary revascularization. METHODS: Patients who were scheduled a routine coronary angiography via a femoral artery were enrolled. Arterial waveforms were traced at aortic root and external iliac artery using coronary catheters at baseline and 3 min after handgrip exercise. Augmentation index (AIx) was measured on the recorded aortic pressure waveform, and pulse wave velocity (PWV) was calculated using the ECG-gated time difference of the upstroke of arterial waveforms and distance between aortic root and external iliac artery. RESULTS: Total 37 patients were evaluated. Both PWV and AIx increased after handgrip exercise. ΔPWV was significantly correlated with ΔAIx (r = 0.344, P = 0.037). Patients were divided into higher and lower ΔPWV or ΔAIx groups based on the median values of 0.4 m/sec and 3.3%, respectively. Patients with higher PWV had more 2- or 3-vessel CAD (69% vs. 27%, P = 0.034), and underwent percutaneous coronary intervention (PCI) more frequently (84% vs. 50%, P = 0.038), but higher ΔAIx was not associated with either the lesion extent or PCI. Area under curve (AUC) of ΔPWV in association with PCI by C-statistics was 0.70 (95% confidence interval [CI] 0.51-0.88; P = 0.056). In multiple logistic regression analysis, ΔPWV was significantly associated with PCI (odds ratio 7.78; 95% CI 1.26-48.02; P = 0.027). CONCLUSIONS: Higher ΔPWV after isometric handgrip exercise was associated with the lesion extent of CAD and the necessity for coronary revascularization, but higher ΔAIx was not.

Effect of beta-blocker therapy in patients with or without left ventricular systolic dysfunction after acute myocardial infarction.

AIMS: This observational study aimed to investigate the association between beta-blocker therapy and clinical outcomes in patients with acute myocardial infarction (AMI), especially with mid-range or preserved left ventricular systolic function. METHODS AND RESULTS: Among 13 624 patients enrolled in the Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH), 12 200 in-hospital survivors were selected. Patients with beta-blockers showed significantly lower 1-year major adverse cardiac events (MACE), which was a composite of cardiac death, MI, revascularization, and readmission due to heart failure [9.7 vs. 14.3/100 patient-year; hazard ratio (HR) 0.84, 95% confidence interval (CI) 0.72-0.97; P = 0.022). However, this association had a significant interaction with left ventricular ejection fraction (LVEF). Beta-blocker therapy at discharge was associated with lower 1-year MACE in patients with LVEF ≤40% (HR 0.63, 95% CI 0.48-0.81; P < 0.001), and 40%

Iodine Uptake in Retroperitoneal Cysts after Radioactive Iodine Treatment.

Radioactive iodine ablation has long-lasting effects on remnant thyroid tissue and metastasis from well-differentiated thyroid cancer. After radioactive iodine treatment, scintigraphy is a major imaging modality for detecting metastasis and assessing its management. False-positive iodine uptake can be found in many aberrant locations, including cysts. This report describes iodine uptake in retroperitoneal cysts in a 62-year-old woman diagnosed with papillary thyroid carcinoma. Radioiodine scintigraphy was performed after iodine therapy. Abnormally increased iodine activity was noted in the left upper abdomen. Additional radiologic examinations helped in preventing invasive biopsy.

Detecting Synchronous Thyroid Adenoma and False-Positive Findings on Technetium-99m MIBI Single Photon-Emission Computed Tomography/Computed Tomography.

Technetium (Tc)-99m-methoxyisobutylisonitrile (MIBI) single photon-emission computed tomography/computed tomography (SPECT/CT) is now being used increasingly for preoperative localization of parathyroid adenomas. Tc-99m-MIBI scintigraphy in a 52-year-old man with a diagnosis of primary hyperparathyroidism revealed two focal areas with retention of radioactivity in the left lobe of the thyroid gland on the delayed phase of MIBI SPECT/CT but no significant focal radioactive uptake on MIBI planar images. The patient subsequently underwent left partial parathyroidectomy. Histological analysis identified one lesion to be thyroid hyperplasia and the other to be parathyroid adenoma. This case demonstrates the value of MIBI SPECT/CT for localization of a parathyroid lesion when compared with planar images and that false-positive findings can lead to misdiagnosis in a patient with coexisting thyroid disease. An appropriate diagnostic work-up that includes Tc-99m MIBI SPECT/CT in addition to ultrasonography is helpful for an accurate diagnosis in patients with concomitant thyroid disease.

Increased pulse wave velocity and augmentation index after isometric handgrip exercise in patients with coronary artery disease.

BACKGROUND: Arterial stiffness of patients with coronary artery disease (CAD), which is expected to be increased due to a generalized atherosclerotic process of human body, may be more evident after the acute increase of blood pressure (BP) or peripheral vascular resistance. Isometric handgrip exercise is a simple and easily applicable method to achieve this goal. We investigated the changes of hemodynamic parameters and arterial stiffness indexes after handgrip exercise in patients with CAD. METHODS: Forty-two subjects, who underwent coronary angiography (CAG), were enrolled. After CAG, baseline arterial waveforms were traced at the aortic root and external iliac artery using right coronary catheters. Arterial waveforms were recorded at 1, 2, and 3 min in the aortic root and at 3 min in the external iliac artery after isometric handgrip exercise at 30% ~ 40% of the maximal handgrip power. Augmentation pressure (AP) and augmentation index (AIx) were measured at aortic pressure waveforms. Pulse wave velocity (PWV) was calculated using the ECG-gated time difference of the upstroke of arterial waveforms and the distance between the aortic root and the external iliac artery. RESULTS: Thirty patients had CAD (CAD group), and others showed no significant coronary stenosis (non-CAD group). Baseline hemodynamic parameters including AIx and PWV were not different between both groups. After isometric handgrip exercise, central systolic blood pressure (BP), central diastolic BP, central pulse pressure, peripheral systolic BP, and peripheral pulse pressure were increased in all patients. AIx inclined significantly from 1 min after exercise only in patients with CAD (before 17.7% ± 9.7% vs. 3 min after exercise 22.3% ± 10.7%, p < 0.001). PWV also increased significantly after exercise only in patients with CAD (before 10.03 ± 1.99 m/s vs. 3 min after 11.09 ± 2.45 m/s, p < 0.001). CONCLUSIONS: Arterial stiffness indexes at rest were not different between patients with and without CAD. After isometric handgrip exercise, increased arterial stiffness became evident only in patients with CAD.

An Assay of Measuring Platelet Reactivity Using Monoclonal Antibody against Activated Platelet Glycoprotein IIb/IIIa in Patients Taking Clopidogrel.

BACKGROUND AND OBJECTIVES: Residual platelet reactivity in patients who are taking clopidogrel is commonly measured with VerifyNow assay, which is based on the principle of light transmission aggregometry. However, to evaluate the residual platelet reactivity, it would be more accurate if the reactivity of platelet glycoprotein (GP) IIb/IIIa is directly monitored. In this study, PAC1, a monoclonal antibody against activated platelet GP IIb/IIIa, was used to measure the residual platelet reactivity. SUBJECTS AND METHODS: Twenty seven patients with coronary artery disease taking clopidogrel were enrolled. Platelets in whole blood were stained with fluorescein isothiocyanate (FITC)-conjugated PAC1. Mean fluorescence intensity (MFI) and % positive platelets (PP) were measured with flow cytometry, and the binding index (BI; MFI × %PP/100) was calculated. P2Y12 reaction unit (PRU) and % inhibition of VerifyNow assay were also measured in the usual manner. RESULTS: PRU of VerifyNow assay correlated significantly with MFI, %PP, and BI at 10 µM (r=0.59, 0.73, and 0.60, respectively, all p<0.005) and 20 µM of adenosine diphosphate (ADP; r=0.61, 0.75, and 0.63, respectively, all p<0.005). The % inhibition also correlated significantly with MFI, %PP, and BI at 10 µM (r=-0.60, -0.69, and -0.59, respectively, all p<0.005) and 20 µM of ADP (r=-0.63, -0.71, and -0.62, respectively, all p<0.005). CONCLUSION: Direct measurements of the reactivity of platelet GP IIb/IIIa were feasible using PAC1 and flow cytometry in patients taking clopidogrel. Further clinical studies are required to determine the cut-off values which would define high residual platelet reactivity in patients on this treatment protocol.