Byung Joo Sun

University of Ulsan, Urusan, Ulsan, South Korea

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Publications (21)101.66 Total impact

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    ABSTRACT: Although surgery is recommended for pediatric patients with supracristal ventricular septal defects (sVSDs) to prevent progression of aortic regurgitation (AR), outcomes in adolescents and adults with sVSDs are not known.
    Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 07/2014; · 2.98 Impact Factor
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    ABSTRACT: This study sought to compare long-term outcomes of early surgery with a conventional treatment strategy in asymptomatic patients with severe mitral regurgitation (MR). The timing of surgery in asymptomatic severe MR remains controversial. From 1996 to 2009, 610 consecutive asymptomatic patients (364 men, age; 50±14 years) with severe degenerative MR and preserved left ventricular function were evaluated prospectively. Early surgery was performed on 235 patients and the conventional treatment strategy was chosen for 375 patients. We compared overall mortality, cardiac mortality and cardiac events (operative mortality, cardiac mortality, repeat surgery and urgent admission due to heart failure) between the two treatment strategies in the propensity-matched cohort. For the 207 propensity-score matched pairs, early surgery had a lower risk of cardiac mortality (HR 0.109; 95% CI, 0.014 to 0.836; P = 0.033) and cardiac events (HR 0.216; 95% CI, 0.083 to 0.558; P = 0.002) than conventional treatment. On Cox proportional hazard model analysis, the risk of cardiac events was significantly lower in the early surgery group than in the conventional treatment group in patients aged ≥ 50 years (HR 0.221; 95% CI, 0.086 to 0.567; P = 0.002), but not significantly different in those aged < 50 years (P = 0.20). Compared with conservative management, early surgery is associated with significant long-term reductions of cardiac mortality and cardiac events in asymptomatic severe MR. These benefits were evident among patients aged ≥ 50 years.
    Journal of the American College of Cardiology 03/2014; · 14.09 Impact Factor
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    ABSTRACT: We present a case of 48-year-old male who presented with coronary artery fistula draining into left ventricle. Transthoracic echocardiography showed abnormal blood flow draining into left ventricle, with enlarged coronary arteries and multiple vascular structures around ventricular myocardium. Coronary computed tomography revealed dilatation of entire left coronary artery which was wrapping around left ventricle, and draining into the posterior side of left ventricle. He did not undergo any invasive treatment, because he was not symptomatic.
    Journal of cardiovascular ultrasound 03/2014; 22(1):28-31.
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    ABSTRACT: Background Although surgery is recommended for pediatric patients with supracristal ventricular septal defects (sVSDs) to prevent progression of aortic regurgitation (AR), outcomes in adolescents and adults with sVSDs are not known. Methods In this retrospective observational study, clinical data without surgery were obtained in 60 patients with sVSDs (group 1; mean age, 36 ± 13 years), 120 age- and defect size–matched patients with perimembranous ventricular septal defects (group 2), and 52 patients with sVSDs who underwent surgery (group 3; mean age, 32 ± 11 years). Results Aortic sinus wall prolapse (38% vs 3%, P < .0001) and moderate to severe AR (7% vs 0%, P = .012) were more frequently observed in group 1 than in group 2. Five, three, and two patients in group 1 had surgery during follow-up because of rupture of the aneurysm of the sinus of Valsalva, endocarditis, and heart failure, respectively. Group 1 had a lower 12-year clinical event-free (surgery and endocarditis) rate (76 ± 9% vs 94 ± 4%, P = .031) but an equivalent overall survival rate (100% vs 94 ± 3%, P = .143) compared with group 2. Patients with maximal prolapsing aortic sinus wall length > 7 mm showed a higher frequency of aneurysm of the sinus of Valsalva rupture than those with no prolapse or maximal prolapsing length ≤ 7 mm (80% [four of five] vs 2% [one of 55], P < .001). The event-free and overall survival rates were comparable between groups 1 and 3, with equivalent 10-year AR progression–free survival rates (94 ± 5% vs 91 ± 5%, P = .301). Conclusions Aneurysm of the sinus of Valsalva rupture, rather than AR progression, was the main clinical event. Watchful monitoring of patients with high-risk echocardiographic features may be a rational option.
    Journal of the American Society of Echocardiography. 01/2014;
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    ABSTRACT: Although statins reduce cardiac events in hypertensive patients with cardiovascular risk factors, the effect of statins on coronary flow reserve (CFR) has not been examined. We tried to examine the effect of rosuvastatin on CFR in hypertensive patients at cardiovascular risk. CFR was studied in 56 hypertensive patients (40 men; 61±9 years) with cardiovascular risk factors and without coronary artery disease in a prospective clinical trial. Using Doppler echocardiography, coronary flow velocity in the distal left anterior descending artery was recorded at baseline and during intravenous adenosine infusion, and CFR was defined as the ratio of hyperemic to basal average peak diastolic flow velocity. The primary efficacy measure was defined as the change in CFR after rosuvastatin therapy for 12 months. CFR was measured successfully in 55 (98%) of 56 enrolled patients. CFR was 3.16 ± 0.44 at baseline and negatively correlated with age (R = −0.30, P = 0.025). All patients continued rosuvastatin 10 mg/day without any serious adverse events. After rosuvastatin therapy, serum total cholesterol, LDL-cholesterol, and high-sensitivity C-reactive protein (hsCRP) significantly decreased from 222 ± 18 to 142 ± 20 mg/dL, 148 ± 21 to 85 ± 18 mg/dL, and 1.7 ± 2.9 to 1.2 ± 3.1 mg/L, respectively (all P < 0.01). CFR significantly increased from 3.16 ± 0.44 to 3.31 ± 0.42 (P < 0.001). The change in CFR correlated with the change in LDL-cholesterol (R = −0.28, P = 0.040) but not with the change in hsCRP. In conclusion, CFR was significantly improved after 12 months of rosuvastatin therapy in hypertensive patients at cardiovascular risk and average levels of serum cholesterol. (ClinicalTrials.gov, NCT01490398)
    The American Journal of Cardiology. 01/2014;
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    ABSTRACT: Subclinical atrial fibrillation (AF) and patent foramen ovale (PFO) are the major causes of cryptogenic stroke, and neuroimaging may help distinguish the cause. We compared the imaging characteristics of ischemic stroke caused by PFO (PFO-stroke) and AF (AF-stroke). We recruited 117 patients with PFO-stroke and 358 patients with AF-stroke after excluding other causes. The lesion patterns were classified according to number, location, size, and pertinent vascular territory and were compared between the 2 groups. Occlusion of the corresponding artery and its recanalization rate were also investigated. The lesion pattern of a PFO-stroke was more frequently observed as a single cortical infarction (34.2% versus 3.1%; P<0.001) or multiple small (<15 mm) scattered lesions (23.1% versus 5.9%; P<0.001) and in the vertebrobasilar artery territory (44.4% versus 22.9%; P<0.001). By contrast, AF-stroke was more frequently observed as a large cortico-subcortical infarction or confluent lesion (>15 mm) with additional lesions in multicirculatory territories. For a PFO-stroke, occlusion of the corresponding vessel on angiography was less frequent (34.2% versus 71.5%; P<0.001), and the neurological deficit evaluated by the National Institutes of Health Stroke Scale was mild (3.48±4.16 versus 9.15±7.35; P<0.001). The recanalization rate was also lower (57.1% versus 78.3%; P=0.007). A PFO-stroke usually appears as a single cortical or multiple small ischemic lesions in the vertebrobasilar circulation without any visible vessel occlusion on angiography. The recanalization rate is significantly lower than in AF-stroke. These imaging characteristics of PFO-stroke may help to diagnose the mechanism and determine the treatment strategy.
    Stroke 09/2013; · 6.16 Impact Factor
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    ABSTRACT: Carbon monoxide is a nonirritant, odorless, colorless gas. Its effects are prominent in organs most sensitive to oxygen deprivation, such as the heart, brain, and kidney. Although less frequently, an association between thromboembolic events and carbon monoxide poisoning has been shown in the literatures. In this case, we report a case of atrial thrombus associated with carbon monoxide poisoning.
    Journal of cardiovascular ultrasound 12/2012; 20(4):205-8.
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    ABSTRACT: To evaluate factors associated with aortic enlargement in patients with a bicuspid aortic valve (BAV) and the impact of isolated aortic valve replacement (AVR). A retrospective analysis of clinical data in a tertiary referral hospital. We performed a cross-sectional analysis of 595 patients with BAV to assess variables determining maximal ascending aortic dimension. To measure annual dilatation rates, baseline and follow-up echocardiograms were analysed in 70 patients with BAV (BAV-AVR group) and 48 with a tricuspid aortic valve (TVA-AVR group) who underwent isolated AVR, and compared with 65 patients with BAV who did not undergo AVR (BAV-NAVR group). Aortic regurgitation (AR) severity was associated with aortic sinus diameter (p<0.001), whereas aortic stenosis severity with the tubular diameter (p<0.001). Multivariate analysis showed that age was an independent factor for both sinus and tubular diameter with AR severity being for aortic sinus diameter and moderate to severe aortic stenosis or AR being for aortic tubular diameter. Despite younger age and lower prevalence of moderate to severe valvular dysfunction at baseline, the annual dilatation rates at sinus and tubular part were significantly higher in the BAV-NAVR than in the BAV-AVR and TAV-AVR groups (p<0.05 each), which did not differ in the BAV-AVR and TAV-AVR groups (p=0.402 for sinus and p=0.394 for tubular part). Age-dependent aortic enlargement associated with significant valvular dysfunction and the protective effects of isolated AVR in patients with BAV indicate that valvular dysfunction is a major determinant to the development of aortopathy.
    Heart (British Cardiac Society) 12/2012; 98(24):1822-7. · 5.01 Impact Factor
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    ABSTRACT: The timing and indications for surgical intervention to prevent systemic embolism in infective endocarditis remain controversial. We conducted a trial to compare clinical outcomes of early surgery and conventional treatment in patients with infective endocarditis. We randomly assigned patients with left-sided infective endocarditis, severe valve disease, and large vegetations to early surgery (37 patients) or conventional treatment (39). The primary end point was a composite of in-hospital death and embolic events that occurred within 6 weeks after randomization. All the patients assigned to the early-surgery group underwent valve surgery within 48 hours after randomization, whereas 30 patients (77%) in the conventional-treatment group underwent surgery during the initial hospitalization (27 patients) or during follow-up (3). The primary end point occurred in 1 patient (3%) in the early-surgery group as compared with 9 (23%) in the conventional-treatment group (hazard ratio, 0.10; 95% confidence interval [CI], 0.01 to 0.82; P=0.03). There was no significant difference in all-cause mortality at 6 months in the early-surgery and conventional-treatment groups (3% and 5%, respectively; hazard ratio, 0.51; 95% CI, 0.05 to 5.66; P=0.59). The rate of the composite end point of death from any cause, embolic events, or recurrence of infective endocarditis at 6 months was 3% in the early-surgery group and 28% in the conventional-treatment group (hazard ratio, 0.08; 95% CI, 0.01 to 0.65; P=0.02). As compared with conventional treatment, early surgery in patients with infective endocarditis and large vegetations significantly reduced the composite end point of death from any cause and embolic events by effectively decreasing the risk of systemic embolism. (EASE ClinicalTrials.gov number, NCT00750373.).
    New England Journal of Medicine 06/2012; 366(26):2466-73. · 51.66 Impact Factor
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    ABSTRACT: Diabetes mellitus is a major risk factor for coronary artery disease (CAD) and for diffuse and progressive atherosclerosis. We evaluated the outcomes of drug-eluting stent (DES) placement and coronary artery bypass grafting (CABG) in 891 diabetic patients (489 for DES implantation and 402 for CABG) and 2,151 nondiabetic patients (1,058 for DES implantation and 1,093 for CABG) with multivessel CAD treated from January 2003 through December 2005 and followed up for a median 5.6 years. Outcomes of interest included death; the composite outcome of death, myocardial infarction (MI), or stroke; and repeat revascularization. In diabetic patients, after adjusting for baseline covariates, 5-year risk of death (hazard ratio 1.01, 95% confidence interval 0.77 to 1.33, p = 0.96) and the composite of death, MI, or stroke (hazard ratio 1.03, 95% confidence interval 0.80 to 1.31, p = 0.91) were similar in patients undergoing DES or CABG. However, rate of repeat revascularization was significantly higher in the DES group (hazard ratio 3.69, 95% confidence interval 2.64 to 5.17, p <0.001). These trends were consistent in nondiabetic patients (hazard ratio 0.80, 95% confidence interval 0.55 to 1.16, p = 0.23 for death; hazard ratio 0.77, 95% confidence interval 0.56 to 1.05, p = 0.10 for composite of death, MI, or stroke; hazard ratio 2.77, 95% CI 1.95 to 3.91, p <0.001 for repeat revascularization). There was no significant interaction between diabetic status and treatment strategy on clinical outcomes (p for interaction = 0.36 for death; 0.20 for the composite of death, MI, or stroke; and 0.40 for repeat revascularization). In conclusion, there was no significant prognostic influence of diabetes on long-term treatment with DES or CABG in patients with multivessel CAD.
    The American journal of cardiology 03/2012; 109(11):1548-57. · 3.58 Impact Factor
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    ABSTRACT: Takotsubo cardiomyopathy (TTC) is an infrequent cardiac syndrome characterized by acute onset chest pain with apical ballooning on echocardiography. It is often triggered by severe emotional or physical stress, and in contrast to acute myocardial infarction (AMI), the regional wall motion abnormality returns to normal within days. Here, we describe a 62-year-old female who presented with acute onset chest pain during treatment for a liver abscess. We presumed a diagnosis of AMI because of ST segment elevation on electrocardiography and elevated cardiac enzyme levels. However, the patient's coronary arteries were normal on angiography, and apical ballooning was seen on echocardiography. A diagnosis of TTC was made, and the patient was managed with intensive cardiopulmonary support using vasopressors in our hospital's medical intensive care unit. The patient's symptoms improved, but persistent severe left ventricular dysfunction was detected on follow-up echocardiography. After 5 weeks, a new apical mural thrombus appeared, and anticoagulation therapy was started. The apical ballooning persisted 3 months later, although the patient's overall ejection fraction was slightly improved. The apical thrombus was completely resolved without any embolic event. Non-adrenergic inotropics can be recommended in TTC with shock, and clinicians should keep in mind the potential risk of thrombus formation and cardioembolism.
    The Korean Journal of Internal Medicine 12/2011; 26(4):455-9.
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    ABSTRACT: The proper way of revascularization remains controversial in patients with ischemic mitral regurgitation (IMR). We sought to compare the long-term results of percutaneous coronary intervention (PCI) and surgical revascularization in IMR. From 1996 to 2008, 185 consecutive patients (132 men; age, 63 ± 9 years) with significant IMR underwent PCI (PCI group) (n=66) or coronary artery bypass graft surgery (OP group) (n=119). In the OP group, 68 (57%) patients also underwent concomitant mitral annuloplasty. Significant IMR was defined as functional MR occurring >1 week after myocardial infarction with an effective regurgitant orifice area ≥ 0.2 cm(2). During a median follow-up of 54 months, there were 2 operative mortalities, 26 cardiac deaths, and 11 heart failure hospitalizations in the OP group and 22 cardiac deaths and 10 heart failure hospitalizations in the PCI group. The survival and cardiac mortality rates were not significantly different between the 2 groups, but event-free survival rates were significantly higher in the OP group. For the 45 propensity score-matched pairs, the risk of cardiac events was significantly lower in the OP group than in the PCI group (hazard ratio, 0.499; 95% CI, 0.251 to 0.990; P=0.043). Compared with patients who underwent coronary artery bypass graft surgery alone, event-free survival rates were significantly higher in those who underwent additional mitral annuloplasty. Compared with PCI, surgical revascularization is associated with an improved long-term event-free survival, and concomitant mitral annuloplasty should be considered in patients with significant IMR.
    Circulation 09/2011; 124(11 Suppl):S156-62. · 15.20 Impact Factor
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    ABSTRACT: Basal septal thinning or localized aneurysmal dilatation without coronary artery disease has been described as a characteristic finding suggestive of cardiac sarcoidosis. We sought to assess the prevalence of this characteristic echocardiographic finding in patients with pacemaker (PM) or implantable cardiac defibrillator (ICD). Echocardiography of patients who received PM or ICD were retrospectively analyzed. Patients with marked thinning and akinesia confined to the basal septum (type 1), or posterolateral wall resulting in localized aneurysmal outward bulging (type 2) without history of myocardial infarction or significant coronary stenosis were included for analysis. Among 1,357 consecutive patients, 21 exhibited suggestive echocardiographic findings (type 1/2=15/6) with a mean ejection fraction of 37±11%. The prevalence was 1.2% in the PM group and 4.0% in the ICD group. Only 3 patients showed histologically confirmable sarcoidosis in lymph nodes, lung and heart, respectively. Endomyocardial biopsy was attempted in 6 patients, but failed to demonstrate sarcoidosis. The 1-, 2-, 4- and 6-year clinical events (death, cardiac transplantation and hospital admission)-free survival rates were 100%, 85.7±7.6%, 75.0±9.7% and 48.6±12.4%, respectively. During follow-up, two patients with PM underwent ICD implantation, and another underwent heart transplantation. Prevalence of echocardiographic features suggesting prevalence of cardiac sarcoidosis is low in patients who underwent device implantation. However, considering the very low yield of endomyocardial biopsy and the rare extracardiac manifestations in cardiac sarcoidosis, characteristic echocardiographic findings could be an adjunctive diagnostic criterion in these patients.
    Korean Circulation Journal 06/2011; 41(6):313-20.
  • American Journal of Cardiology - AMER J CARDIOL. 01/2011; 107(8).
  • American Journal of Cardiology - AMER J CARDIOL. 01/2011; 107(8).
  • American Journal of Cardiology - AMER J CARDIOL. 01/2011; 107(8).
  • American Journal of Cardiology - AMER J CARDIOL. 01/2011; 107(8).
  • American Journal of Cardiology - AMER J CARDIOL. 01/2011; 107(8).
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    ABSTRACT: Because stress-induced cardiomyopathy (SIC) is increasingly being observed during routine daily practice, we sought to explore the clinical features and factors that determine the outcome of SIC in a tertiary referral hospital. Patients with typical left ventricular (LV) takotsubo (apical ballooning) or inverted takotsubo on 2-dimensional echocardiography were prospectively enrolled, and their clinical data were analyzed. Over a 63-month period, 56 consecutive patients (median age and interquartile range=64 years [52-74 years]) were identified. Women comprised 79% (44/56) of all patients. The triggering events were acute medical illness, including sepsis and hypoxemia in 29 patients (52%, group A), in-hospital surgery/procedure in 17 patients (30%, group B), and emotional stress in 10 patients (18%, group C). Chest pain was more frequently observed in group C (50%) than in groups A (14%) and B (6%) (P=.021), whereas dyspnea was the presenting symptom in groups A and B. Typical takotsubo and inverted takotsubo were observed in 48 and 8 patients, with a median ejection fraction of 33%. Other abnormalities included dynamic LV outflow tract obstruction (n=2), LV thrombus (n=2), and right ventricular dysfunction (n=12). Nine deaths (16%) occurred during hospitalization. The groups did not differ in mortality. The Acute Physiology and Chronic Health Evaluation II score (odds ratio 1.405; 95% confidence interval, 1.091-1.810; P=.009) and absence of LV function recovery within 1 week (ejection fraction<50%) (odds ratio 14.080; 95% confidence interval, 1.184-167.475; P=.036) were independent factors associated with mortality. During clinical follow-up up to 6 months, 3 more patients died, 2 of whom had recurrences of SIC. SIC in a tertiary referral hospital was mainly associated with physical stressors and characterized by diverse clinical presentations, high mortality, and occasional fatal recurrences.
    Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 07/2010; 23(7):766-71. · 2.98 Impact Factor
  • Journal of The American College of Cardiology - J AMER COLL CARDIOL. 01/2010; 55(10).