Clinical and Genetic Features of Korean Inherited Arrhythmia Probands

Background and Objectives@#Inherited arrhythmia (IA) is a more common cause of sudden cardiac death in Asian population, but little is known about the genetic background of Asian IA probands. We aimed to investigate the clinical characteristics and analyze the genetic underpinnings of IA in a Korean cohort. @*Methods@#This study was conducted in a multicenter cohort of the Korean IA Registry from 2014 to 2017. Genetic testing was performed using a next-generation sequencing panel including 174 causative genes of cardiovascular disease. @*Results@#Among the 265 IA probands, idiopathic ventricular fibrillation (IVF) and Brugada Syndrome (BrS) was the most prevalent diseases (96 and 95 cases respectively), followed by long QT syndrome (LQTS, n=54). Two-hundred-sixteen probands underwent genetic testing, and 69 probands (31.9%) were detected with genetic variant, with yield of pathogenic or likely pathogenic variant as 6.4%. Left ventricular ejection fraction was significantly lower in genotype positive probands (54.7±11.3 vs. 59.3±9.2%, p=0.005). IVF probands showed highest yield of positive genotype (54.0%), followed by LQTS (23.8%), and BrS (19.5%). @*Conclusions@#There were significant differences in clinical characteristics and genetic yields among BrS, LQTS, and IVF. Genetic testing did not provide better yield for BrS and LQTS. On the other hand, in IVF, genetic testing using multiple gene panel might enable the molecular diagnosis of concealed genotype, which may alter future clinical diagnosis and management strategies.

Lipid-Core Plaque Assessed by Near-Infrared Spectroscopy and Procedure Related Microvascular Injury

BACKGROUND AND OBJECTIVES: Microvascular damage due to distal embolization during percutaneous coronary intervention (PCI) is an important cause of periprocedural myocardial infarction. We assessed the lipid-core plaque using near-infrared spectroscopy (NIRS) and microvascular dysfunction invasively with the index of microcirculatory resistance (IMR) and evaluated their relationship. METHODS: This study is pilot retrospective observational study. We analyzed 39 patients who performed NIRS before and after PCI, while fractional flow reserve, thermo-dilution coronary flow reserve (CFR) and IMR were measured after PCI. The maximum value of lipid core burden index (LCBI) for any of the 4-mm segments at the culprit lesion (culprit LCBI(4mm)) was calculated at the culprit lesion. We divided the patients into 2 groups using a cutoff of culprit LCBI(4mm) ≥500. RESULTS: Mean pre-PCI LCBI was 333±196 and mean post-PCI IMR was 20±14 U. Post-PCI IMR was higher (15.6±7.3 vs. 42.6±17.6 U, p<0.001) and post-PCI CFR was lower (3.7±2.2 vs. 2.1±1.0, p=0.029) in the high LCBI group. Pre-PCI LCBI was positively correlated with post-PCI IMR (ρ=0.358, p=0.025) and negatively correlated with post-PCI CFR (ρ=−0.494, p=0.001). The incidence of microvascular dysfunction (IMR ≥25 U) was higher in the high LCBI group (9.4% vs. 85.7%, p<0.001). However, there were no significant differences in the incidences of creatine Kinase-MB (9.4% vs. 14.3%, p=0.563) and troponin-I elevation (12.5% vs. 14.3%, p=1.000). CONCLUSIONS: A large lipid-core plaque at the ‘culprit’ lesion is observed higher incidence of post-PCI microvascular dysfunction after PCI. Prospective study with adequate subject numbers will be needed.

Lipid-Core Plaque Assessed by Near-Infrared Spectroscopy and Procedure Related Microvascular Injury

BACKGROUND AND OBJECTIVES@#Microvascular damage due to distal embolization during percutaneous coronary intervention (PCI) is an important cause of periprocedural myocardial infarction. We assessed the lipid-core plaque using near-infrared spectroscopy (NIRS) and microvascular dysfunction invasively with the index of microcirculatory resistance (IMR) and evaluated their relationship.@*METHODS@#This study is pilot retrospective observational study. We analyzed 39 patients who performed NIRS before and after PCI, while fractional flow reserve, thermo-dilution coronary flow reserve (CFR) and IMR were measured after PCI. The maximum value of lipid core burden index (LCBI) for any of the 4-mm segments at the culprit lesion (culprit LCBI(4mm)) was calculated at the culprit lesion. We divided the patients into 2 groups using a cutoff of culprit LCBI(4mm) ≥500.@*RESULTS@#Mean pre-PCI LCBI was 333±196 and mean post-PCI IMR was 20±14 U. Post-PCI IMR was higher (15.6±7.3 vs. 42.6±17.6 U, p<0.001) and post-PCI CFR was lower (3.7±2.2 vs. 2.1±1.0, p=0.029) in the high LCBI group. Pre-PCI LCBI was positively correlated with post-PCI IMR (ρ=0.358, p=0.025) and negatively correlated with post-PCI CFR (ρ=−0.494, p=0.001). The incidence of microvascular dysfunction (IMR ≥25 U) was higher in the high LCBI group (9.4% vs. 85.7%, p<0.001). However, there were no significant differences in the incidences of creatine Kinase-MB (9.4% vs. 14.3%, p=0.563) and troponin-I elevation (12.5% vs. 14.3%, p=1.000).@*CONCLUSIONS@#A large lipid-core plaque at the ‘culprit’ lesion is observed higher incidence of post-PCI microvascular dysfunction after PCI. Prospective study with adequate subject numbers will be needed.

Quality of Anticoagulation and Treatment Satisfaction in Patients with Non-Valvular Atrial Fibrillation Treated with Vitamin K Antagonist: Result from the KORean Atrial Fibrillation Investigation II

BACKGROUND: Vitamin K antagonist (VKA) to prevent thromboembolism in non-valvular atrial fibrillation (NVAF) patients has limitations such as drug interaction. This study investigated the clinical characteristics of Korean patients treated with VKA for stroke prevention and assessed quality of VKA therapy and treatment satisfaction. METHODS: We conducted a multicenter, prospective, non-interventional study. Patients with CHADS2 ≥ 1 and treated with VKA (started within the last 3 months) were enrolled from April 2013 to March 2014. Demographic and clinical features including risk factors of stroke and VKA treatment information was collected at baseline. Treatment patterns and international normalized ratio (INR) level were evaluated during follow-up. Time in therapeutic range (TTR) > 60% indicated well-controlled INR. Treatment satisfaction on the VKA use was measured by Treatment Satisfaction Questionnaire for Medication (TSQM) after 3 months of follow-up. RESULTS: A total of 877 patients (age, 67; male, 60%) were enrolled and followed up for one year. More than half of patients (56%) had CHADS2 ≥ 2 and 83.6% had CHA2DS2-VASc ≥ 2. A total of 852 patients had one or more INR measurement during their follow-up period. Among those patients, 25.5% discontinued VKA treatment during follow-up. Of all patients, 626 patients (73%) had poor-controlled INR (TTR < 60%) measure. Patients' treatment satisfaction measured with TSQM was 55.6 in global satisfaction domain. CONCLUSION: INR was poorly controlled in Korean NVAF patients treated with VKA. VKA users also showed low treatment satisfaction.

Design of Korean Noninvasive Risk Evaluation Study for Sudden Cardiac Death from Infarction or Heart Failure: Myocardial infarction study of K-REDEFINE registry

BACKGROUND AND OBJECTIVES: Despite significant advances in the treatment of acute myocardial infarction (MI), the prevention of sudden cardiac death (SCD), the most common mode of death in patients with MI, remains challenging. Furthermore, previous Korean MI registries did not address the issue of post-MI SCD. Additional risk stratifiers of post-MI SCD are still required to compensate for the limitation of using left ventricular ejection fraction to predict lethal arrhythmic events. SUBJECTS AND METHODS: We designed the first Korean prospective nationwide multicenter registry primarily focused on SCD; the Korean noninvasive Risk Evaluation study for sudden cardiac DEath From INfarction or heart failurE (K-REDEFINE). The registry consists of 2 groups of patients presenting with (1) acute MI or (2) acute heart failure (HF) at 25 tertiary referral cardiovascular centers. The primary endpoint of the MI group study of K-REDEFINE registry is the incidence and risk factors of post-MI SCD. In particular, the association between the risk of SCD and non-invasive Holter-based electrocardiogram (ECG) variables will be evaluated, such as T-wave alternans (marker of repolarization heterogeneity) and heart rate turbulence/variability (a marker of autonomic function). Other secondary study outcomes include atrioventricular arrhythmias, HF-related admission, repeated myocardial ischemic events, stroke, and overall deaths. CONCLUSION AND PERSPECTIVE: The K-REDEFINE registry will provide new prospects for the better management of MI patients with high risk of SCD by clarifying the burden and predictors of SCD and the clinical utility of various non-invasive ambulatory ECG-based variables in risk stratification for SCD in this patient population.

Time Variance of Electrocardiographic Transmural Dispersion in Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: The mechanism responsible for lethal ventricular arrhythmia (LVA) after acute myocardial infarction (AMI) remains unclear. SUBJECTS AND METHODS: The corrected QT interval (QTc) and interval from the peak to the end of the T wave (TpTe) were measured, which indicated myocardial transmural dispersion of repolarization (TDR) in 72 patients with AMI. TpTe was also expressed as a corrected value, [TpTe/QTe]x100% and TpTe/√RR. These parameters were obtained from all the 12-leads of electrocardiography after arrival at the hospital, just before and after percutaneous coronary intervention (PCI), and at 4, 24, and 48 hours and 5 days after PCI. RESULTS: Analyzing with repeated measures analysis of variance, the TpTe, [TpTe/QTe]x100% and TpTe/√RR after AMI showed significant changes in time variance. The patients were divided into LVA (17 patients, 24%) and non-LVA group (55 patients, 76%). The [TpTe/ QTe]×100% (V₂: 25±7% vs. 22±5%, p=0.036) and TpTe/√RR (V₂: 109 ± 42 ms vs. 88 ± 22 ms, p=0.05, V₃: 108±39 ms vs. 91±27 ms, p=0.048) in V₂ and V₃ leads were prolonged in the LVA group after PCI. The [TpTe/QTe]×100% (28±9 % vs. 22±5%, p=0.025) and TpTe/√RR (129±53 ms vs. 99±41 ms, p=0.05) in V₃ lead were prolonged in the LVA group 24 hours after PCI. CONCLUSION: The mechanisms responsible for LVA after AMI may be associated with increased TDR, and PCI may have an important role in reducing LVA.

Design of Korean Noninvasive Risk Evaluation Study for Sudden Cardiac Death from Infarction or Heart Failure: Heart failure study of K-REDEFINE registry

BACKGROUND AND OBJECTIVES: Sudden cardiac death (SCD) is one of the most common causes of death in patients with heart failure (HF). However, there are no available data on SCD in previous Korean HF registries. Additionally, although widely used, the utility of left ventricular (LV) ejection fraction (EF) in risk stratification for SCD is limited. SUBJECTS AND METHODS: The Korean non-invasive Risk Evaluation study for sudden cardiac DEath From INfarction or heart failurE (KREDEFINE) is the first Korean prospective, nationwide multicenter registry, primarily focused on SCD. The registry consists of 2 groups of patients presenting with (1) acute HF or (2) acute myocardial infarction (MI) at 25 tertiary referral cardiovascular centers. Using the HF-group data of the K-REDEFINE registry, the incidence and risk factors of SCD in patients with HF will be assessed. In particular, the efficacy of Holter-based ECG variables, such as T-wave alternans (marker of repolarization heterogeneity) and heart rate turbulence/ variability (maker of autonomic function), in risk stratification for SCD will be evaluated. Other cardiovascular outcomes will also be analyzed, including atrioventricular arrhythmias, HF-related admission, stroke, and overall deaths. CONCLUSION AND PERSPECTIVE: The K-REDEFINE registry will pave the way for better management of patients with HF at high risk of SCD by elucidating the burden and risk factors of SCD and the clinical utility of various non-invasive ambulatory ECG-based parameters in risk stratification for SCD in this patient population.

Anatomical Discrepancy Between The Coronary Sinus and the Mitral Annulus by Fluoroscopy

BACKGROUND AND OBJECTIVES: Intracardiac electrocardiograms (ECGs) from the coronary sinus (CS) provide important information for identifying a left-sided bypass tract. However, a previous study revealed an anatomical discrepancy between the CS and mitral annulus (MA) in cadaver hearts. The purpose of this study was to evaluate the anatomical relationship between the CS and MA in the living body by using fluoroscopy. SUBJECTS AND METHODS: We analyzed patients who had an ablation for 42 left-sided bypass tracts and one paroxysmal atrial fibrillation. A left atriogram was performed during the ablation by using a pigtail catheter via the transseptal approach. The distances between the CS and MA were measured at 30° right anterior oblique (RAO) and 60° left anterior oblique (LAO) projections at the end of ventricular systole and diastole. RESULTS: The distances between the CS and MA at the RAO projection were 9.74±3.50, 3.86±2.58, and 9.02±6.04 mm during systole and 12.89±5.59, 3.97±3.24, and 10.71±4.12 mm during diastole at the proximal, middle, and distal CS, respectively. The distances between the CS and MA at the LAO projection were 6.84±2.77, 1.80±1.51, and 4.57±3.24 mm during systole and 9.91±3.25, 4.21±3.59, and 7.02±3.12 mm during diastole at the proximal, middle, and distal CS, respectively. CONCLUSION: An anatomical discrepancy was detected between the CS and MA in most cases. Therefore, intracardiac ECGs of the CS cannot exactly localize left-sided bypass tracts.

The Korean Heart Rhythm Society's 2014 Statement on Antithrombotic Therapy for Patients with Nonvalvular Atrial Fibrillation: Korean Heart Rhythm Society

In patients with nonvalvular atrial fibrillation (AF), the risk of stroke varies considerably according to individual clinical status. The CHA2DS2-VASc score is better than the CHADS2 score for identifying truly lower risk patients with AF. With the advent of novel oral anticoagulants (NOACs), the strategy for antithrombotic therapy has undergone significant changes due to its superior efficacy, safety and convenience compared with warfarin. Furthermore, new aspects of antithrombotic therapy and risk assessment of stroke have been revealed: the efficacy of stroke prevention with aspirin is weak, while the risk of major bleeding is not significantly different from that of oral anticoagulant (OAC) therapy, especially in the elderly. Reflecting these pivotal aspects, previous guidelines have been updated in recent years by overseas societies and associations. The Korean Heart Rhythm Society has summarized the new evidence and updated recommendations for stroke prevention of patients with nonvalvular AF. First of all, antithrombotic therapy must be considered carefully and incorporate the clinical characteristics and circumstances of each individual patient, especially with regards to balancing the benefits of stroke prevention with the risk of bleeding, recommending the CHA2DS2-VASc score rather than the CHADS2 score for assessing the risk of stroke, and employing the HAS-BLED score to validate bleeding risk. In patients with truly low risk (lone AF, CHA2DS2-VASc score of 0), no antithrombotic therapy is recommended, whereas OAC therapy, including warfarin (international normalized ratio 2-3) or NOACs, is recommended for patients with a CHA2DS2-VASc score > or =2 unless contraindicated. In patients with a CHA2DS2-VASc score of 1, OAC therapy should be preferentially considered, but depending on bleeding risk or patient preferences, antiplatelet therapy or no therapy could be permitted.

Usefulness of Hyperemic Microvascular Resistance Index as a Predictor of Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction

BACKGROUND AND OBJECTIVES: Microvascular function is a useful predictor of left ventricular functional changes in patients with ST-segment elevation myocardial infarction (STEMI). We evaluated the usefulness of the hyperemic microvascular resistance index (hMVRI) for predicting long-term major adverse cardiovascular events (MACEs) in patients with STEMI assessed immediately after primary percutaneous coronary intervention (PCI). SUBJECTS AND METHODS: hMVRI were evaluated in 145 patients with first acute STEMI treated with primary PCI using an intracoronary Doppler wire. hMVRI was defined as the ratio of mean aortic pressure over hyperemic averaged peak velocity of infarct-related artery. Major adverse cardiovascular events (MACEs) included cardiac death and re-hospitalization for congestive heart failure. RESULTS: During the mean follow-up of 85+/-43 months, MACEs occurred in 17.2% of patients. Using a receiver-operating characteristics analysis, hMVRI >2.82 mm Hg.cm-1.sec (sensitivity: 87%; specificity: 69%; and area under curve: 0.818) was the best cut-off values for predicting future cardiac events. The Cox proportional hazard analysis showed that hMVRI was an independent predictor for long-term MACEs (hazard ratio 1.741, 95% confidence interval 1.348-2.264, p2.82 mm Hg.cm-1.sec (p<0.001). CONCLUSION: hMVRI was a strong predictor of long-term MACEs in patients with STEMI treated with primary PCI.

Impact of Arterial Stiffness on Regional Myocardial Function Assessed by Speckle Tracking Echocardiography in Patients with Hypertension

BACKGROUND: Arterial stiffening may affect regional myocardial function in hypertensive patients with normal ejection fraction (EF). METHODS: Brachial-ankle pulse wave velocity (PWV) was measured in 70 patients, of mean age 48 +/- 14 years, with untreated hypertension and EF > 55%. Using two-dimensional-speckle tracking echocardiography, we measured longitudinal and circumferential strain (epsilon) and strain rate (SR). Basal and apical rotations were measured using short axis views. RESULTS: The mean systolic and diastolic blood pressure in these patients was 152 +/- 15 mmHg and 92 +/- 11 mmHg, respectively. The mean value of PWV was 1578 +/- 274 cm/s. PWV significantly correlated with age (r = 0.682, p 1700 cm/s compared to those with PWV < or = 1400 cm/s or those with PWV 1400-1700 cm/s. CONCLUSION: In hypertensive patients with normal ejection fraction, arterial stiffening contributes to impaired systolic and diastolic function of the regional myocardium. Compensatory increases in ventricular twist were diminished in patients with advanced stage of vascular stiffening.

Validation of Three-Dimensional Echocardiography for Quantification of Aortic Root Geometry: Comparison with Multi-Detector Computed Tomography

BACKGROUND: Three-dimensional (3D) echocardiography has been reported to be valuable for evaluating the geometry of cardiac chambers. We validated the accuracy of 3D transthoracic echocardiography for quantifying aortic root geometry in comparison with cardiac multi-detector computed tomography (MDCT). METHODS: Twenty-three patients who underwent cardiac MDCT and showed normal left ventricular ejection fraction (> 55%), as assessed by 2-dimensional transthoracic echocardiography, were enrolled (12 male, mean 53 +/- 9 years). We defined the aortic root volume as the volume from the aortic annulus to the sinotubular junction. The aortic root volume at end-diastole measured by both cardiac MDCT and 3D echocardiography was assessed. RESULTS: The cross-sectional area of the aortic root was asymmetric. At the annulus level, the cross-sectional area showed asymmetric triangle. From the aortic annulus to the most dilated point of the sinus of Valsalva, the asymmetric triangular shape was maintained. From the most dilated point of the sinus of Valsalva to the sinotubular junction, the cross-sectional shape of the aortic root changed to oval. The average aortic root volumes measured by 3D echocardiography (ARV-3DE) were 13.6 +/- 4.8 mL at end-diastole and 14.1 +/- 5.3 mL at end-systole, respectively. The average aortic root volume measured by MDCT at end-diastole (ARV-CT) was 14.1 +/- 5.7 mL. At end-diastole, the ARV-3DE correlated well with the ARV-CT (R2 = 0.926, difference = 0.5 +/- 1.7 mL), and the two methods were in excellent agreement (the percent difference was 0%). CONCLUSION: Our results demonstrate both the feasibility and accuracy of 3D echocardiography for the clinical assessment of the geometry of the aortic root.

Long Journey of Sclerosant From the Esophagus to the Right Atrium

A 34-year-old man, who had been treated with an endoscopic injection of a mixture of n-butyl-2-cyanoacrylate (Histoacryl) and Lipiodol for control of variceal bleeding 6 months previously, presented with an intracardiac mass in the right atrium (RA). Two-dimensional echocardiography revealed an intracardiac mass in the RA that appeared to extend from the inferior vena cava. The origin of the sclerosant was traced by computed tomography (CT). This is a very rare case in which the sclerosant migration route was demonstrated by CT scan. The findings of this case suggest that the systemic migration of sclerosant into an intracardiac chamber should be considered in patients with an intracardiac mass, especially with a history of previous sclerotherapy for variceal bleeding.

Acute Mitral Regurgitation due to Spontaneous Chordal Rupture in a Patient With Obstructive Hypertrophic Cardiomyopathy

A 69-year-old male presented with obstructive hypertrophic cardiomyopathy, mitral valve regurgitation, and myxomatous mitral valve prolapse. A spontaneous chordal rupture and acute severe mitral regurgitation resulted in abrupt clinical deterioration despite complete relief of severe left ventricular outflow tract obstruction and systolic anterior motion of the anterior mitral leaflet. The patient underwent extensive cardiac surgery due to intractable heart failure. Surgical procedures included a mitral valve replacement, a septal myectomy, and the Maze procedure.

Lupus Myocarditis Presenting as Acute Congestive Heart Failure: A Case Report

A young woman who had a delivery history 3 months previously presented with dyspnea and orthopnea. Initial findings of physical examination, chest radiography, and echocardiogram showed typical congestive heart failure with severe left ventricular (LV) dysfunction. At first, we considered peripartum cardiomyopathy because she had given birth to a baby 3 months previously. However, even though we massively tried conventional drug therapy for 10 days, the patient still remained with refractory heart failure. We performed additional laboratory studies such as complement level and autoantibodies, of which the results supported systemic lupus erythematosus. We could make the diagnosis of acute lupus myocarditis and treated her with corticosteroid. The symptoms were dramatically disappeared and LV function also improved.

A Case of Huge Coronary Aneurysm After Implantation of a Sirolimus-Eluting Stent

This report describes the case of a 62-year-old woman who was previously diagnosed with stable angina. Coronary angiography revealed clinically significant stenosis in the middle of the left anterior descending (LAD) artery, the first diagonal branch, the distal left circumflex (LCX) artery and the proximal posterior descending artery (PDA). After administering aspirin and clopidogrel, the patient underwent implantation of sirolimus-eluting stents in the middle LAD artery and the first diagonal branch. Bare-metal stents were implanted in the distal LCX artery and the proximal PDA. Nineteen months later, follow-up coronary angiography revealed aneurysmal dilation at the middle LAD artery and the first diagonal branch. Forty-six months after implantation of the sirolimus-eluting stents, the size of the coronary aneurysm had increased to 12.4 mm; however, no sign of aneurysmal dilatation was observed at the bare-metal stent sites. This suggested that the implantation of the sirolimus-eluting stent was partially responsible for causing the coronary aneurysm.

Correlation Between the Serum Bilirubin Level and the Coronary Microvascular Integrity in Diabetic Patients

BACKGROUND AND OBJECTIVES: Bilirubin has a protective role in suppressing atherosclerosis and coronary artery disease by its potent physiological antioxidant properties. There has been no comparative study on the relation between the bilirubin level and the coronary microvascular function in diabetic patients. This study investigated whether the bilirubin level correlates with the coronary microvascular integrity in diabetes by assessing the coronary flow velocities after successful percutaneous coronary intervention (PCI). SUBJECTS AND METHODS: Fifty patients (31 males and 19 females, mean age 60+/-11) with angina and who received elective PCI were studied. Using an intracoronary Doppler wire, the coronary flow velocity reserve (CFR), the hyperemic microvascular resistance index and the phasic coronary flow velocity patterns were measured after PCI. RESULTS: The mean value of the fasting blood glucose was 211+/-88 mg/dL, the man value of glycated hemoglobin A1c (HbA1c) was 8.1+/-1.6% and the mean serum total bilirubin level was 0.59+/-0.21 mg/dL. CFR was significantly correlated with the serum bilirubin level (r=0.485, p<0.001), HbA1c (r=-0.432, p=0.003) and the fasting blood glucose (r=-0.361, p=0.011). On multivariate analysis, HbA1c, bilirubin and left ventricular hypertrophy showed independent relationships with coronary microvascular dysfunction (p=0.003, p=0.004, p=0.033, respectively). CONCLUSION: These results suggest that glycemic control and elevated serum bilirubin may protect diabetic patients from coronary microvascular dysfunction.

Echocardiographic Plains Reflecting Total Amount of Epicardial Adipose Tissue as Risk Factor of Coronary Artery Disease

BACKGROUND: Several studies suggested that epicardial adipose tissue (EAT) might be associated with metabolic syndrome and coronary atherosclerosis. But, little had been studied whether the thickness of EAT on echocardiography could represent the whole amount of EAT. The purpose of this study was to identify the best echocardiographic methods reflecting total amount of EAT. \METHODS: Sixty subjects (32 women, mean: 58+/-12 years-old) who underwent 64-slice multidetector computed tomography (MDCT) were consecutively enrolled. All CT scanning was performed one Brilliance CT-64-channel configuration scanner (Philips, Cleveland, USA) and axially contiguous 10-mm-thickeness sections were obtained from aortic valve to diaphragm level. EAT area was manually traced in each slice and summed up. The EAT thickness was measured as the echo-lucent or echo-dense space between epicardium and pericardium at parasternal long-axis, modified 4-chamber, and apical 4-chamber view. RESULTS: The EAT thickness at parasternal long-axis and modified 4-chamber view and the sum of EAT thickness from each views (median thickness: 1.0, 2.8, 1.1 and 5.0 mm, respectively) were all correlated with total EAT area on MDCT. Among echo parameters, the EAT thickness measured on parasternal long-axis view during diastole correlated best with total EAT area on MDCT (r=0.572, p<0.001). CONCLUSION: The echocardiographic EAT measurement might be easily accessible and less harmful method representing whole amount of EAT. The measurement of the thickness of EAT on parasternal long-axis view during diastole by echocardiography might be feasible and reliable in the studying field of EAT.

Correlation between Thrombolysis in Myocardial Infarction, the Myocardial Perfusion Grade and the Myocardial Viability Indices after Primary Percutaneous Coronary Intervention in ST Segment Elevation Myocardial Infarction

BACKGROUND AND OBJECTIVES: The thrombolysis in myocardial infarction (TIMI) myocardial perfusion grade (TMPG) is associated with the long term clinical outcomes. This study compared the TMPG with the myocardial viability as determined by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and with improvement of the left ventricular (LV) function on echocardiography. SUBJECTS AND METHODS: We enrolled 44 consecutive patients (37 men: age 56+/-11 years) who underwent primary percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI). We assessed the coronary flow reserve (CFR), the diastolic deceleration time (DDT), the coronary wedge pressure (Pcw) and the coronary wedge pressure/mean aortic pressure (Pcw/Pa). All the patients underwent FDG-PET scans on the 7th day after primary PCI. The patients were divided into 3 groups according to the TMPG (TMPG 0/1: n=18, TMPG 2: n=14, TMPG 3: n=12). RESULTS: There was a significant correlation between the TMPG and the CFR, DDT, Pcw and Pcw/Pa (r=0.367, p=0.017; r=0.587, p<0.001; r=-0.513, p<0.001; r=-0.614, p<0.001, respectively). There was a significant correlation between the TMPG and the % of FDG uptake (r=0.587, p<0.001) and the patients with TMPG 3 had the most favorable % of FDG uptake (TMPG 0/1 vs TMPG 2 vs TMPG 3; 42.0+/-12.3% vs 53.9+/-11.2% vs 59.3+/-13.3%, p=0.001). On echocardiography, the patients with TMPG 3 revealed an improvement of the LV ejection fraction (53.4+/-9.9% vs 60.0+/-7.0%, p=0.004) and the patients with TMPG 2 and TMPG 3 revealed improvement of their regional wall motion abnormality (RWMA) index (1.44+/-0.26 vs 1.24+/-0.18, p=0.022; 1.35+/-0.26 vs 1.15+/-0.18, p=0.018, respectively). CONCLUSION: The angiographically determined TMPG might be clinically useful for the assessment of myocardial viability and it might be a useful predictor for improvement of the LV function in patients suffering with STEMI.

A Novel Index of Microcirculatory Resistance for Invasively Assessing Myocardial Viability after Primary Angioplasty for Treating Acute Myocardial Infarction: Comparison with FDG-PET Imaging

BACKGROUND AND OBJECTIVES: The state of the coronary microcirculation is an important determinant of the myocardial viability and clinical outcomes for patients suffering with acute myocardial infarction (AMI). However, there are scant comparative studies on the most reliable invasive, on-site measurement for assessing the microvascular integrity and myocardial viability in AMI patients. The aim of this study is to evaluate the usefulness of a novel index of microcirculatory resistance (IMR) and the coronary physiologic parameters for predicting the myocardial viability after primary percutaneous coronary intervention (PCI) in AMI patients. SUBJECTS AND METHODS: Twenty-four patients (21 males, mean age: 55+/-11 years) underwent primary PCI for AMI (LAD: 17, RCA: 6, LCX: 1) were enrolled. After successful PCI, using a pressure-temperature sensor-tipped coronary wire, the thermodilution-derived CFR (CFRthermo) and coronary wedge pressure (Pcw) were measured and the ratio of the Pcw and the mean aortic pressure (Pcw/Pa) was calculated, along with the IMR, which was defined as the distal coronary pressure divided by the inverse of the hyperemic mean transit time. 18F-fluorodeoxyglucose (FDG) PET was performed after primary PCI at 7 days post-AMI to evaluate the myocardial viability by the regional percentage of FDG uptake in the infarct-related segments. RESULTS: There were good correlations between all the coronary pressure measurements and the regional FDG uptake (CFRthermo, r=0.454, p=0.026; Pcw, r=-0.407, p=0.048; Pcw/Pa, r=-0.480, p=0.018; IMR, r=-0.696, p<0.001, respectively). Multiple logistic regression analysis demonstrated that the IMR was an adjusted predictor for myocardial viability as defined by the 50% FDG-PET threshold value among all the coronary pressure measurements (OR=0.884, p=0.021). The cut-off value of IMR for predicting myocardial viability was 22 U (a sensitivity of 82%, a specificity of 85% and an accuracy of 85%). CONCLUSIONS: Intracoronary pressure wire-based indexes are useful for on-site assessment of myocardial viability after primary PCI. IMR is a novel index that represents the microvascular integrity, and it is a better predictor of myocardial damage than the current techniques for evaluating the microvasculature after primary PCI.