Kyung-Jong Yoo

Yonsei University, Sŏul, Seoul, South Korea

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Publications (69)211.59 Total impact

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    ABSTRACT: Heart diseases such as myocardial infarction (MI) can damage individual cardiomyocytes, leading to the activation of cell death programs. The most scrutinized type of cell death in the heart is apoptosis, and one of the key events during the propagation of apoptotic signaling is the formation of apoptosomes, which relay apoptotic signals by activating caspase-9. As one of the major components of apoptosomes, apoptotic protease activating factor 1 (Apaf-1) facilitates the formation of apoptosomes containing cytochrome c (Cyto-c) and deoxyadenosine triphosphate (dATP). Thus, it may be possible to suppress the activation of the apoptotic program by down-regulating the expression of Apaf-1 using miRNAs. To validate this hypothesis, we selected a number of candidate miRNAs that were expected to target Apaf-1 based on miRNA target prediction databases. Among these candidate miRNAs, we empirically identified miR-17 as a novel Apaf-1-targeting miRNA. The delivery of exogenous miR-17 suppressed Apaf-1 expression and consequently attenuated formation of the apoptosome complex containing caspase-9, as demonstrated by co-immunoprecipitation and immunocytochemistry. Furthermore, miR-17 suppressed the cleavage of procaspase-9 and the subsequent activation of caspase-3, which is downstream of activated caspase-9. Cell viability tests also indicated that miR-17 pretreatment significantly prevented the norepinephrine-induced apoptosis of cardiomyocytes, suggesting that down-regulation of apoptosome formation may be an effective strategy to prevent cellular apoptosis. These results demonstrate the potential of miR-17 as an effective anti-apoptotic agent. Copyright © 2015. Published by Elsevier Inc.
    Biochemical and Biophysical Research Communications 08/2015; DOI:10.1016/j.bbrc.2015.08.028 · 2.28 Impact Factor
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    ABSTRACT: To determine whether plasma cystatin C and creatinine levels after isolated off-pump coronary artery bypass grafting (OPCAB) are predictive of postoperative renal dysfunction and clinical outcomes. Between January 2008 and December 2013, 1033 who underwent isolated OPCAB were recruited. The patients were divided into three groups according to the preoperative level of cystatin C: low (0.83 mg/L>), mid (0.83-1.13 mg/L) and high (1.13 mg/L<). The endpoints of all-cause mortality and major adverse cerebrovascular and cardiovascular events were compared among three groups using the Kaplan-Meier method. The predictive power of cystatin C was compared with creatinine using receiver operating curves. Follow-up was complete in all of the included patients at a mean of 2.9±1.5 years. Within the follow-up period, 9 early (30-day mortality) and 46 late deaths occurred. The 30-day mortality was zero, four (44%), and five (56%) cases in low, mid and high groups, respectively (p=0.03). The cut-off value of cystatin C for renal dysfunction prediction was approximately 1.04 (mg/L, p<0.001), and cystatin C showed greater predictive power than creatinine for renal dysfunction (area under the curve=0.73 vs 0.65; p=0.01). One-year and five-year overall survival in low, mid and high groups were 99.2%, 98.9% and 94.3%, and 97.9%, 97.3% and 86.3%, respectively (low vs high, p=0.01). Cystatin C is a stronger predictor of postoperative renal dysfunction than serum creatinine, and its level is directly correlated with mid-term OPCAB adverse results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to
    Heart (British Cardiac Society) 07/2015; DOI:10.1136/heartjnl-2015-307986 · 6.02 Impact Factor
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    ABSTRACT: During ischemia-reperfusion (IR) injury of the heart, Ca(2+) overload occurs, leading to cardiomyocyte dysfunction and eventual cell death by apoptosis. Since preventing Ca(2+) overload during IR injury has been reported to protect cardiomyocytes, interrupting Ca(2+) signaling cascades leading to Ca(2+) overload may exert protective effect on cardiomyocytes under hypoxic condition. One of the key regulators of the intracellular Ca(2+) level during IR injury is Na(+)-Ca(2+) exchanger 1 (NCX1), whose down-regulation during IR injury conferred protection of heart. In the present study, we examined whether down-regulation of NCX1 using exogenous microRNA ameliorates apoptosis of cardiomyocytes under hypoxic condition. Here, we identified miR-132 as a novel microRNA targeting the NCX1, whose expression increased during hypoxia. Delivery of miR-132 suppressed the increase of intracellular Ca(2+) in cardiomyocytes under hypoxia, and the expressions of apoptotic molecules, such as Bax, cytochrome C, and caspase 3, and the number of apoptotic cells were also decreased by exogenous miR-132 treatment. These results suggest the potential of miR-132 as an effective therapeutic agent against IR damage to heart by preventing Ca(2+) overload during hypoxic condition and warrant further studies to validate its anti-apoptotic effect in vivo. Copyright © 2015. Published by Elsevier Inc.
    Biochemical and Biophysical Research Communications 03/2015; 460(4). DOI:10.1016/j.bbrc.2015.03.129 · 2.28 Impact Factor
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    ABSTRACT: Purpose To investigate the diagnostic performance of coronary computed tomographic (CT) angiography for selecting candidates for coronary artery bypass graft (CABG) surgery according to the 2011 American College of Cardiology Foundation (ACCF) and American Heart Association (AHA) guidelines for CABG surgery and determine the added value of SYNTAX (Synergy between PCI with TAXUS and Cardiac Surgery) scoring for selecting CABG surgery candidates. Materials and Methods Approval was obtained from the Institutional Review Board, and informed consent was waived for this retrospective study. A total of 399 patients (mean age, 63.8 years; 244 men and 155 women) who underwent both coronary CT angiography and invasive coronary angiography were included. Eligible criteria for CABG surgery were established on the basis of the 2011 ACCF/AHA guidelines. Results from coronary CT angiography and invasive coronary angiography were retrospectively reviewed, and SYNTAX scores were determined. The diagnostic performance of coronary CT angiography for selecting CABG surgery candidates was calculated with invasive coronary angiography as the reference method. The diagnostic performance of coronary CT angiography alone, the CT-based SYNTAX score, and the combined coronary CT angiography with CT-based SYNTAX score were assessed by using a combination of invasive coronary angiography and invasive coronary angiography-based SYNTAX scores as a reference method. Statistical analyses were performed by using the generalized estimating equation, independent t test, Mann-Whitney U test, Wilcoxon signed rank test, Fisher exact test, and χ(2) statistics. Results The overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value of coronary CT angiography for selecting CABG surgery candidates were 96.5%, 96.5%, 88.3%, and 99.0%, respectively. When a combination of invasive coronary angiography with an invasive coronary angiography-based SYNTAX score was used as a standard reference, combined coronary CT angiography with a CT-based SYNTAX score had higher specificity and PPV (98.3% and 86.0%, respectively) than did coronary CT angiography alone (84.5% and 40.4%, respectively; P < .0001). Conclusion Coronary CT angiography had diagnostic accuracy comparable to that of invasive coronary angiography for selecting CABG surgery candidates, and combining a CT-based SYNTAX score with coronary CT angiography can be a highly specific method for selecting CABG surgery candidates. (©) RSNA, 2015.
    Radiology 03/2015; DOI:10.1148/radiol.15141216 · 6.21 Impact Factor
  • Sang-Ho Cho · Hyun-Chel Joo · Kyung-Jong Yoo · Young-Nam Youn
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    ABSTRACT: Background Anomalous aortic origin of coronary artery is a rare congenital condition in which the coronary artery arises from the opposite sinus of Valsalva. Although many patients are asymptomatic at the time of presentation or diagnosis, surgical correction is recommended due to the risk of ischemic sudden death. We describe seven cases of right coronary artery (RCA) arising from the left sinus of Valsalva, causing the hypoperfusion through RCA. Patients and Methods All patients underwent preoperative coronary angiography, echocardiography, and cardiac stress test (treadmill test [TMT], n = 4; technetium-99m sestamibi [MIBI], n = 3). In four patients, coronary computed tomography (CT) was performed. On the basis of preoperative test results, unroofing of the coronary artery (n = 3) or off-pump coronary artery bypass (OPCAB; n = 4; patients with coronary arterial occlusive disease) was performed. In two patients, intraoperative flow meter was performed and showed the improvement of flow rate through RCA. Results Postoperative CT angiography after OPCAB confirmed good graft patency (n = 4); CT angiography after unroofing demonstrated widely patent neo-orifice (n = 3). All patients underwent postoperative cardiac stress tests including TMT and MIBI, which revealed no evidence of ischemia. All patients were asymptomatic and returned to normal activities (mean follow-up, 41 months; 32-49 months). Conclusion The appropriate surgical procedure based on specific anatomical details, perioperative evaluation, and follow-up by focusing on the ischemia may lead to successful surgical outcomes of this coronary anomaly.
    The Thoracic and Cardiovascular Surgeon 06/2014; 63(05). DOI:10.1055/s-0034-1376256 · 1.08 Impact Factor
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    ABSTRACT: Background Redo coronary artery bypass grafting (CABG) is still associated with increased morbidity and mortality as compared to the first-time operation. Further, the application of the off-pump technique to redo CABG is limited due to technical difficulties. The aim of this retrospective study was to analyze early and midterm results after redo CABG and compare the outcome of redo on-pump and off-pump CABG. Methods From June 1996 to October 2011, elective redo CABG was performed in 32 patients. Mean age was 64.8 years (on pump 64.3 years vs. off pump 65.5 years; p=0.658), and 21 patients were male. Among these patients, 14 (43.8%) underwent on-pump CABG, and 18 (56.2%) underwent off-pump CABG. Results Internal thoracic artery was used in 22 patients (68.8%), and total arterial revascularization was achieved in 17 patients (53.1%). The average number of distal anastomoses was 2.13, and the rate of incomplete revascularization was 43.8%. The rate of total arterial revascularization was higher in the off-pump group (14.3% vs. 83.3%, p<0.001), and the use of saphenous vein graft was more in the on-pump group (78.6% vs. 16.7%, p<0.001). Overall hospital mortality was 3.1% (n=1) and was comparable in both groups (on pump 7.1% vs. off pump 0%; p=0.249). Postoperative complications occurred in 9 patients (64.2%), and the rate of complications was high in the on-pump group without statistical significance (64.2% vs. 33.3%, p=0.082). The mean follow-up duration was 5.4 years, and overall survival at 10 years was 86.0%±10.5%. There was no significant difference in the 10-year survival rate between the two groups (79.6% vs. 100%, p=0.225). Conclusion Redo CABG can be safely performed with acceptable mortality. Redo off-pump coronary artery bypass is feasible with low mortality and morbidity, comparable target vessel bypass grafting, and long-term survival. The off-pump technique might be considered a safe option for redo CABG in high-risk patients.
    06/2014; 47(3):225-32. DOI:10.5090/kjtcs.2014.47.3.225
  • Young-Nam Youn · Gijong Yi · Sak Lee · Hyun-Chel Joo · Kyung-Jong Yoo
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    ABSTRACT: Background Dual antiplatelet therapy with aspirin and clopidogrel is currently recommended in off-pump coronary artery bypass (OPCAB). However, no data exist concerning platelet reactivity on clopidogrel after OPCAB. The aim of this study was to assess the relationship between platelet reactivity and late major adverse cardiovascular events (MACEs) after OPCAB. Methods In this prospective, single-center, observational study, on-clopidogrel platelet reactivity was measured using a point-of-care assay (VerifyNow system) in 859 patients who underwent OPCAB with one or more vein grafts. The primary endpoint was late MACEs (30 days-1 year) including cardiac death, nonfatal myocardial infarction, and target vessel revascularization. Receiver operating characteristic curve analysis was used to estimate the cutoff value of P2Y12 reaction units (PRUs) for MACEs. Results The optimal cutoff value for post-treatment reactivity for the incidence of late MACEs was ≥188 PRU (area under the curve: 0.72, 95% confidence interval [CI]: 0.68–0.75, p = 0.002). The incidence of late MACEs was significantly higher in the high platelet reactivity (HPR; ≥188 PRU) group than in the low platelet reactivity (LPR; <188 PRU) group (3.6% vs. 1.4%, p = 0.040). Kaplan-Meier analysis revealed 1-year MACE-free survival rates of 98.4 ± 0.5% and 95.9 ± 1.3% in the LPR and HPR groups, respectively (p = 0.034). According to a Cox regression hazard model, HPR was an independent risk factor for late MACE-free survival (Hazard ratio: 3.51, 95% CI: 1.27–9.69, p = 0.015). Conclusion High residual platelet reactivity after clopidogrel administration is strongly associated with 1-year MACE-free survival. Routine measurement of platelet reactivity and thorough monitoring of patients with HPR after OPCAB are warranted.
    American Heart Journal 06/2014; 167(6). DOI:10.1016/j.ahj.2014.01.016 · 4.56 Impact Factor
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    ABSTRACT: The use of thoracic endovascular aortic repair (TEVAR) for chronic DeBakey III type b (CDIIIb) aneurysms is controversial. We analyzed the potential prognostic factors affecting aorta remodeling after this procedure.
    Journal of Thoracic and Cardiovascular Surgery 05/2014; 148(3). DOI:10.1016/j.jtcvs.2014.05.040 · 3.99 Impact Factor
  • Suk-Won Song · Kyung-Jong Yoo · Yoo Rim Shin · Sun-Hee Lim · Bum-Koo Cho
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    ABSTRACT: We sought to analyse the preoperative status of arch vessels by postoperative diffusion-weighted magnetic resonance imaging (DWI) as a potential surrogate marker for cerebral thromboembolism and its relationship to neurocognitive outcomes. Preoperative computed tomography (CT) and postoperative DWI were available for 50 patients who received surgery for acute type A aortic dissection. Two radiologists evaluated CT and DWI scans. Mini-mental status examinations (MMSE) were performed on the same day with DWI. Mean age of participants was 57 ± 14 years. MMSE and DWI were performed 6 ± 3 days after surgery. New cerebral embolisms were evident in 35 of 50 patients (70%) and often occurred as multiple lesions (28/35, 80%; range 2-21). Among patients with multiple lesions, 23 (66%) were clinically silent. Pathological lesions at the origin of the arch vessels correlated with the number and volume of new DWI lesions (P < 0.05). Degree of neurocognitive dysfunction tested by MMSE was negatively associated with age (r = -0.48, P < 0.0001) and left-sided DWI lesion number and volume (r = -0.74, P < 0.0001; r = -0.707, P < 0.0001). DWI revealed new cerebral embolisms in 70% of patients following surgery for acute type A aortic dissection. Lesion number and volume significantly correlated with pathological status of arch vessels. MMSE was representative of left-sided lesions.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 04/2014; 47(2). DOI:10.1093/ejcts/ezu169 · 2.81 Impact Factor
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    ABSTRACT: The safety and efficacy of arterial composite grafts for total arterial revascularization have been demonstrated. The saphenous vein (SV) is a widely used graft because of its accessibility, sufficient length, and ease of manipulation. Our aim was to compare mid-term outcomes of saphenous vein Y-grafts with radial artery Y-grafts joined by anastomosis to the left internal thoracic artery. Records of off-pump coronary artery bypass grafting with composite Y-grafts based on the left internal thoracic artery technique in 552 patients were analyzed retrospectively. After propensity score matching, 79 radial arterial (RA) composite grafts (RA group) and 79 saphenous vein composite grafts (SV group) were compared. The duration of mean follow-up was 24.6±14.6 months (range, 1 to 55 months). There were no differences in surgical mortality, all-cause mortality, or morbidity among the groups. Rates of 4-year survival were 91.7% and 96.3% in the RA and SV groups, respectively (p=0.519). The coronary reintervention-free survival rate and freedom from major adverse cardiovascular or cerebrovascular events were similar in the two groups (p=0.685, p=0.564). Construction of composite Y-grafts using the radial artery or saphenous vein showed similar mid-term results. Long-term follow-up and randomized trials will be needed to confirm our present conclusions.
    08/2013; 46(4):265-73. DOI:10.5090/kjtcs.2013.46.4.265
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    ABSTRACT: BACKGROUND: We evaluated the effect of incomplete revascularization (IR) on the long-term outcomes after off-pump coronary artery bypass grafting. MATERIALS AND METHODS: Of 1553 patients with triple-vessel disease who had undergone consecutive off-pump coronary artery bypass grafting, 1351 (87.0%) had complete revascularization (CR) and 202 had IR (13.0%). After propensity score patient matching, we had 200 patients in each group. Cardiac survival and major adverse cardiac and cerebrovascular events (MACCE) were assessed before and after patient matching. Subgroup analysis was performed to evaluate the interaction between the left ventricular ejection fraction (LVEF) and the completeness of revascularization. The follow-up duration was 60 mo. RESULTS: In the all-patient analysis, the CR group had a lower incidence of in-hospital mortality, cardiac mortality, and MACCE (P = 0.033, P < 0.001, and P = 0.003, respectively). The 5-year cardiac survival was 96.5% ± 0.6% in the CR group and 88.9% ± 2.5% in the IR group (P < 0.001), with a freedom from MACCE rate of 85.4% ± 1.2% and 78.8% ± 3.4%, respectively (P = 0.015). After patient matching, the CR group showed superior 5-year cardiac survival compared with the IR group (96.2% ± 1.4% versus 88.8% ± 2.5%, P = 0.022), with a similar freedom from MACCE rate. IR was identified as an independent predictor of cardiac death (hazard ratio 2.76, 95% confidence interval 1.62-4.70; P < 0.001). IR predicted cardiac death more distinctly in patients with a low LVEF (hazard ratio 5.29, 95% confidence interval 1.71-16.39; P = 0.004) than in those with a preserved LVEF (hazard ratio 2.04, 95% confidence interval 1.02-4.08; P = 0.045). CONCLUSIONS: CR in off-pump coronary artery bypass grafting was related to superior cardiac survival after 5 years of follow-up compared with IR. The benefit of CR was more distinct in those with a low LVEF. CR should be achieved whenever possible, especially in patients with a low LVEF.
    Journal of Surgical Research 06/2013; DOI:10.1016/j.jss.2013.05.042 · 2.12 Impact Factor
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    ABSTRACT: BACKGROUND: Second-generation drug-eluting stents (DESs) are known to have better safety and clinical outcomes compared with the first-generation DESs. We compared the clinical results of off-pump coronary artery bypass grafting (OPCAB) with percutaneous coronary intervention (PCI) using second-generation DESs. METHODS: The study enrolled 1,821 patients with triple-vessel or left main coronary disease, or both, who underwent OPCAB or PCI with second-generation DESs from 2008 to 2011. Major adverse cardiac and cerebrovascular events (MACCEs), including death, myocardial infarction, stroke, and target vessel revascularization, were retrospectively compared between the two groups in a real-world and in a matched population (n = 1,294). Follow-up duration was 23.0 ± 13.0 months (range, 0 to 56 months). RESULTS: The postprocedural mortality rate was comparable between the two groups (p = 0.384). The overall rate of MAACEs was 7.3% in the PCI group and 3.8% in the OPCAB group (p = 0.001). The 3-year rate of freedom from MACCEs was 88.4% ± 1.5% in the PCI group and 94.9% ± 1.0% in the OPCAB group (p < 0.001). In a matched population comparison, the 3-year rate of freedom from a MACCE was 87.5% ± 2.0% in the PCI group and 95.3% ± 1.2% in the OPCAB group (p = 0.001). The determining factors were nonfatal myocardial infarction and target vessel revascularization. The OPCAB group showed a superior rate of freedom from MACCEs in the triple-vessel (p = 0.008) and left main subset analysis (p = 0.001). CONCLUSIONS: The OPCAB showed superior outcomes in triple-vessel or left main disease, or both, compared with PCI in the second-generation DES era after 23 months of follow-up. Nonfatal myocardial infarction and target vessel revascularization were the determining factors. Longer follow-up with randomization will clarify our results.
    The Annals of thoracic surgery 04/2013; 96(2). DOI:10.1016/j.athoracsur.2013.03.004 · 3.65 Impact Factor
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    Journal of the American College of Cardiology 03/2013; 61(20). DOI:10.1016/j.jacc.2013.02.033 · 15.34 Impact Factor
  • Suk-Won Song · Kyung-Jong Yoo · Yoo Rim Shin · Sun-Hee Lim · Bum-Koo Cho
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    ABSTRACT: OBJECTIVES: To avoid deep hypothermia-related side effects, moderate hypothermic circulatory arrest (HCA) is commonly employed during aortic arch repair, thereby jeopardizing end-organ protection. We sought to analyse the effect of intermittent lower body perfusion (ILBP) on end-organ function during repair of acute DeBakey type I aortic dissection (AIAD). METHODS: Between May 2008 and May 2011, 107 patients underwent surgical repair for AIAD. All operations were performed with selective cerebral perfusion (SCP) under either moderate HCA only (n = 57) or moderate HCA with ILBP (n = 50). Adverse outcomes, including operative mortality, permanent neurological deficit, temporary neurological deficit, renal failure requiring dialysis and hepatic dysfunction, were compared between the two groups. RESULTS: The mean body temperature at the initiation of SCP was 28.7 ± 1.9°C. Overall operative mortality occurred in 6 (5.6%) patients. The incidences of permanent neurological deficit and temporary neurological deficit were 1.9 and 4.7%, respectively. None of the 9 (8.4%) patients who suffered postoperative renal failure requiring dialysis received ILBP. The laboratory data showed significantly lower levels of hepatic and kidney enzymes in the ILBP group (P < 0.05). CONCLUSIONS: Significantly lower levels of hepatic and kidney enzymes indicate more effective end-organ protection with the use of ILBP. Our data suggest that ILBP provides more effective end-organ protection during repair of aortic arch under moderate HCA.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 03/2013; 44(6). DOI:10.1093/ejcts/ezt145 · 2.81 Impact Factor
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    ABSTRACT: BACKGROUND: Hyperglycemia exacerbates renal ischemia-reperfusion (IR) injury via aggravated inflammatory response and excessive production of reactive oxygen species. This study aimed to investigate the ability of propofol, a known antioxidant, to protect kidneys against IR injury in hyperglycemic rats in comparison with normoglycemic rats. METHODS: Sixty rats were randomly assigned to four groups: normoglycemia-etomidate, normoglycemia-propofol, hyperglycemia-etomidate, and hyperglycemia-propofol. Anesthesia was provided with propofol or etomidate depending on the group. Also, the rats received 1.2 g/kg dextrose or the same volume of normal saline depending on the group. Renal ischemia was induced for 25 min. The rats were killed, and samples were collected 65 min after starting intravenous anesthetics (sham) and 15 min and 24 h after reperfusion injury to compare the histologic degree of renal tubular damage and levels of inflammatory markers and enzymes related to reactive oxygen species. RESULTS: Compared with etomidate, propofol significantly attenuated tubular damage after reperfusion in hyperglycemic rats. Also, tubular damage was greater under hyperglycemia compared with normoglycemia in the etomidate group, whereas it was similar in the propofol group. Propofol preserved superoxide dismutase level and attenuated the increase in levels of myeloperoxidase, interlukin-1β, and tumor necrosis factor-α after reperfusion compared with etomidate especially in hyperglycemic rats. Propofol also attenuated the production of inducible nitric oxide synthase and phosphorylation of inhibitor of κB and nuclear factor-κB after reperfusion, which were more prominent under hyperglycemia. CONCLUSIONS: Propofol conveyed renoprotection against IR injury by preserved antioxidation ability and attenuated inflammatory response, which were more prominent under hyperglycemia.
    Journal of Surgical Research 03/2013; 183(2). DOI:10.1016/j.jss.2013.02.017 · 2.12 Impact Factor
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    ABSTRACT: BACKGROUND: There have been limited reports on the diagnostic performance and prognostic value of coronary computed tomography angiography (CCTA) for selecting coronary artery bypass graft (CABG) candidates. METHODS: There were 1,018 patients with suspected coronary artery disease who underwent 64-slice multidetector CCTA between July 2009 and January 2010. Of them, we excluded 324 patients who denied further treatment (n = 7), who were lost for unidentified reasons (n = 107), or who were transferred to local clinics (n = 210). The total analysis cohort consisted of 694 patients. We established eligible CABG criteria defined as three-vessel disease, left main coronary disease, and left main coronary artery equivalent disease. Diagnostic performance was determined using conventional coronary angiography as the reference standard. For assessment of the prognostic utility of CCTA, electronic medical records were reviewed to screen for the occurrence of a major adverse cardiac event, defined as cardiac death, nonfatal myocardial infarction, or revascularization. RESULTS: The overall sensitivity, specificity, positive predictive value, and negative predictive value of CCTA for the selection of CABG candidates were 83.3%, 96.2%, 90.9%, and 92.7%, respectively. The presence of CABG criteria on CCTA was an independent prognostic factor for predicting a major adverse cardiac event (hazard ratio, 12.508; 95% confidence interval, 7.353 to 21.278; p < 0.0001). CONCLUSIONS: We found CCTA had a high diagnostic performance for selecting CABG candidates and predicted major adverse cardiac events in CABG candidates referred for CCTA owing to suspected coronary artery disease.
    The Annals of thoracic surgery 02/2013; 95(4). DOI:10.1016/j.athoracsur.2013.01.004 · 3.65 Impact Factor
  • Gijong Yi · Hyun-Chel Joo · Kyung-Jong Yoo
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    ABSTRACT: Background We aimed to assess the impact of C-reactive protein (CRP) on clinical outcomes after off-pump coronary artery bypass grafting (OPCABG). Methods Seven hundred fifty-five consecutive OPCABG patients were divided into two groups according to their preoperative CRP level (normal CRP [NCRP] group [CRP6.0 mg/L] versus high CRP [HCRP] group [CRP>6.0 mg/L]). Outcome measurements were cardiac death and major adverse cardiac and cerebrovascular event (MACCE). ResultsEarly mortality was higher in the HCRP group (p=0.036). During follow-up, cardiac mortality was 1.2% in the NCRP group and 7.1% in the HCRP group (p<0.001). The overall MACCE incidence was 11.2% in the NCRP group and 16.5% in the HCRP group (p=0.042). All-cause mortality was the only determining factor (p<0.001), whereas the incidences of myocardial infarction, stroke, and repeat revascularization were similar between the two groups (p=0.987, p=0.201, p=0.426). The 3-year freedom rates from cardiac death and MACCE were 98.80.5% and 87.5 +/- 1.6% in the NCRP group and 92.5 +/- 1.7% and 84.3 +/- 2.5% in the HCRP group (p<0.001, p=0.09, respectively). Conclusions Patients with HCRP level showed worse clinical outcomes regarding cardiac death and MACCE after OPCABG.
    The Thoracic and Cardiovascular Surgeon 02/2013; 61(8). DOI:10.1055/s-0033-1334124 · 1.08 Impact Factor
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    Jung-Hwan Kim · Yoo-Hwa Hwang · Young-Nam Youn · Kyung-Jong Yoo
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    ABSTRACT: Constrictive pericarditis after coronary artery bypass surgery has been known to affect cardiac output by limiting diastolic ventricular filling. We aimed to assess the influence of postoperative constrictive physiology on the early outcomes of patients undergoing off-pump coronary artery bypass grafting (OPCAB). Between January 2008 and July 2011, 903 patients underwent an isolated OPCAB and postoperative transthoracic-echocardiography. The patient cohort was classified into two groups: group A, constrictive physiology and group B, control group without constrictive physiology. Early outcomes were analyzed between the two groups. Of the total 903 patients, group A consisted of 153 patients (16.9%). The amount of blood loss in group A during the postoperative 24 hours was greater than that of group B, but this was not statistically significant (p=0.20). No significant differences were found in the mortality rates (group A, 0.6%; group B, 1.4%; p=0.40) and 30-day major adverse cardiac and cerebrovascular events (MACCEs; group A, 3.3%; group B, 6.1%; p=0.42). Postoperative constrictive physiology does not affect 30-day MACCEs or other major complications after OPCAB. The results of this study suggest that patients with early postoperative constrictive physiology do not need medical or surgical treatment, and that conservative care is sufficient.
    02/2013; 46(1):22-6. DOI:10.5090/kjtcs.2013.46.1.22
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    ABSTRACT: BACKGROUND: The effect of prosthesis-patient mismatch (PPM) on clinical outcomes after aortic valve replacement remains controversial. We evaluated effect of PPM on long-term clinical outcomes after isolated aortic valve replacement in patients with predominant aortic stenosis. METHODS: We analyzed data from patients with predominant aortic stenosis who underwent isolated aortic valve replacement between January 1995 and July 2010. The indexed effective orifice area, obtained by dividing the in vivo effective orifice area by the patient's body surface area, was used to define PPM as clinically nonsignificant (group I, 224 patients), mild (group II, 52 patients), moderate (group III, 39 patients), and severe (group IV, 36 patients). RESULTS: Early survival was not significantly different among the groups, but overall survival was decreased gradually in group IV. Overall survival at 12 years was lower in group IV than in group I (92.8% ± 2.7% vs 67.0 ± 10.1, respectively; P = .001). Cardiac-related-death-free survival at 12 years was lower in patients with severe PPM. Left ventricular mass index decreased during the follow-up period in all groups. But left ventricular mass index was less decreased in group IV compared with groups I, II, and III. Age, severe PPM, and ejection fraction <40%, and New York Heart Association Functional Class IV were independent risk factors of overall survival on multivariate analysis. Severe PPM was an independent risk factor for cardiac-related death. CONCLUSIONS: Severe PPM showed an adverse effect on long-term survival, and was an independent risk factor for cardiac-related death. In addition, patients with severe PPM showed less decreasing left ventricular mass index during follow-up.
    The Journal of thoracic and cardiovascular surgery 09/2012; 146(5). DOI:10.1016/j.jtcvs.2012.07.101 · 3.99 Impact Factor
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    ABSTRACT: We retrospectively analyzed 28 years of experience with the Bentall procedure in patients with aortic valve, aortic root, and ascending aortic disease. Between March 1982 and December 2010, a total of 218 patients underwent the Bentall procedure using a composite valved conduit. The "inclusion technique" was used in 30 patients (13.8%), the "open-button technique" in 181 patients (83.0%), and the Cabrol technique in 7 patients (3.2%). The early mortality rate was 5.5% (12/218). The mean follow-up duration was 108.0±81.0 months (range: 1-329 months). Seven patients required re-operation, and 1 patient required stent graft insertion at the descending thoracic aorta for progression of aortic arch or descending thoracic aortic dissection or aneurysm after the first operation, and 5 of them had Marfan syndrome. Kaplan-Meier estimated survival rates at 1, 5, 10, 20, and 25 years were 90.4%, 82.7%, 77.6%, 65.3%, and 60.3%, respectively. Freedom from reoperation rates at 1, 5, 10, 20, and 25 years were 99.0%, 98.3%, 95.5%, 90.8%, and 90.8%, respectively. In our experience, the Bentall procedure provided optimal survival with improved functional status. The disease of the aorta may progress, especially in patients with Marfan syndrome. Therefore, careful follow-up with regular computed tomography angiograms should be performed in these patients.
    Yonsei medical journal 09/2012; 53(5):915-23. DOI:10.3349/ymj.2012.53.5.915 · 1.26 Impact Factor

Publication Stats

705 Citations
211.59 Total Impact Points


  • 2007–2015
    • Yonsei University
      • Department of Thoracic and Cardiovascular Surgery
      Sŏul, Seoul, South Korea
  • 2003–2015
    • Yonsei University Hospital
      • • Department of Internal Medicine
      • • Department of Thoracic and Cardiovascular Surgery
      Sŏul, Seoul, South Korea
  • 2008–2013
    • Wonju Severance Christian Hospital
      Genshū, Gangwon, South Korea
  • 2006
    • Hanyang University
      • Division of Chemical Engineering and Bioengineering
      Ansan, Gyeonggi, South Korea