• Journal of Chest Surgery
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• v.38 no.11 s.256
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• pp.761-772
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• 2005

Background: Following the implantation of heart valve prostheses, it is important to maintain therapeutic INR to reduce the risk of thromboembolism. The objective of this study was to suggest a practical dosing guideline for Korean outpatients with prosthetic heart valves managed by a pharmacist-run anticoagulation service (ACS). Material and Method: A retrospective chart review was completed for all patients enrolled in the ACS at Seoul National University Hospital from March, 1997 to September, 2000. Patients who were at least 6 months post-valve replacement and had nontherapeutic INR value (less than 2.0 or greater than 3.0) were included. The data on 688 patients (1,782 visits) requiring dosing adjustment without any known drug or food interaction with warfarin were analyzed. The amount of adjusted dose and INR changes based on the INR at the time of the event were calculated. Aortic valve replacements (AVR) patients and mitral or double valve replacement (MVR/DVR) patients were evaluated separately. Result: Two methods for the warfarin dosage adjustment were suggested: Guideline I (mg-based total weekly dose (TWD) adjustment), Guideline II (percentage-based TWD adjustment). The effectiveness of Guideline 1 was superior to Guideline II overall in patients with both AVR and MVR/DVR. Conclusion: The guideline suggested in this study could be useful when the dosage adjustment of wafarin is necessary in outpatients with mechanical heart valves.

• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.493-501
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• 1996

To assess contribution of T1-201 rest-24 hour delay redistribution in detection of viable myocardium, we studied the predictive value of this redistribution in 17 patients who peformed rest-24 hour delay perfusion SPECT before bypass surgery. Regional wall motion was compared with gated SPECT in 10 patients and echocardiography in 7 patients before and after bypass surgery. Rest and 24 hour delayed uptakes were scored from 0 (normal perfusion) to 3 (defect). In rest SPECT, 56 segments showed perfusion decrease. Thirty four segments(61%) improved after surgery and were defined as viable Nineteen(34%) segments had more uptake of T1-201 at 24 hour delay, and the other 37 segments did not. In 81%(25/31) of segments with mildly decreased perfusion, wall motion after bypass surgery improved, 57% (8/14) of segments with severely decreased perfusion improved, and 9%(1/11) of segments with defects improved. In 14 among 19 segments which had more T1-201 uptakes at 24 hour delay, wall motion was improved(positive predictive value of redistribution: 74%). 20 among 37 segments which had persistent decreases in rest-24 hour redistribution improved and 17 did not(negative predictive value: 46%). Segments having severe perfusion decrease or defects showed improved wall motion after surgery in 64%(7/11), if it had redistribution at delay. Segments with either mildly decreased uptake in resting or rest-delayed redistribution showed improved wall motion in 76%(32/42). Among the 14 segments which showed improvement in wall motion, 10 had partial reversibility in stress-rest images and the other 4 had persistent perfusion defects in stress-rest images. These 4 segments were found viable only with rest-24 hour delayed perfusion SPECT. We concluded that rest T1-201 uptake or redistribution at 24 hour delay should be referred as an evidence to warrant postoperative improvement of abnormal wall motion and we could predict myocardial viability with preoperative rest-24 hour delay perfusion SPECT in the segments with rest perfusion decreases.

• Journal of Life Science
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• v.20 no.9
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• pp.1299-1305
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• 2010

Cardiac troponin-I (cTnI), creatine kinase-MB (CK-MB), and C-reactive protein (CRP) are routine cardiac markers for the diagnosis of cardiovascular disease. Recently, brain natriuretic peptide (BNP) has garnered attention as a marker of heart failure. This study was retrospectively designed to investigate the relationships between preoperative BNP, other cardiac markers levels and perioperative parameters in seventy-four adult patients that underwent off-pump coronary artery bypass grafting (OPCAB) and to assess its usefulness for predicting postoperative outcomes. Preoperative levels of BNP, cTnI, CK-MB, and CRP had significantly positive or negative correlations with echocadiographic parameters. There were significantly positive relationships between BNP, cTnI, CK-MB, and CRP concentration. Postoperative mechanical ventilation time had a positive correlation to preoperative levels of cTnI, CK-MB, and CRP, while ICU-staying period had a positive correlation with BNP, cTnI and CK-MB. These results reveal that a preoperative level of BNP is a good predictor and that its combination with cTnI, CK-MB, and CRP might be useful for diagnosis and comprehensive risk stratification of patients with coronary heart diseases, as well as prognosis of perioperative outcomes in OPCAB patients.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.599-605
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• 1996

A total of 249 patients undergoing isolated coronary revascularization were studied for the occurrence of postoperative atrial fibrillation(AF). Possible associations of this arrhythmia with various preoperative, intraoperative and postoperative factors were studied by univariate and multivariate analysis. The overall incidence of postoperative AF was 15%, with the median time occurence of 48 hours(mean time : 59.1 $\pm$ 56.9 hours) after arrival to the intensive care unit. Cardiac index decreased significantly after occurence of AF(p=0.001). There were no in-hospital complications in those patients with AF. Univariate studies indicated preoperative ejection fract on(EF), triglyceride level, postoperative peak CKMB isoenzpme and atrial pacing to be the dominant factor promoting postoperative AF, with an increasing prevalence in lower EF(p=0.025), triglyceride(p=0.006) and peak CKMB isoenzyme(p=0.002), and in patients with atrial pacing(p=0.001). Hospital stay(p=0.001) and late mortality(p=0.003) were significantly increased in patients with postoperative AF Multivariate analysis showed that body weight and postoperative atrial pacing to be the dominant factor promoting postoperative AF, with an increasing prevalence in over- weight patients(p=0.011) and patients with atrial pacing(p=0.001). Both univariate and multivariate analy- sis showed that the age was not a significant factor but tended to promote postoperative AF respectively (p=0.053, 0.064). After 30.1 $\pm$ 11.4 months gfollow-up, those patients with AF had sinus rhythm. We think that we must try to prevent postoperative AF after ccoronary artery bypass grafting because of its deleterio s hemodynamic effect, prolonged hospital stay, and increased late mortality.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.610-618
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• 2008

Background: There are various treatment modalities for atherosclerotic arterial obstructive disease at the lower limbs, for example, conservative physical therapy, medication, operation etc. Yet it has been established that an arterial bypass operation is the most effective treatment. The aim of this study is to evaluate the effect of arterial bypass operation within our experience and to determine the indicators of treatment. Material and Method: Ninety six patients received arterial bypass operation for atherosclerotic arterial obstructive disease from June 2002 to April 2006. We evaluated the feasibility of arterial bypass operation based on the improvement of symptoms and the ankle-brachial index (ABI) and the surgical outcomes, as based on the complications, the amputation rates and the patency rates. We also assessed the possible risk factors such as gender, age, a smoking history, co-morbidities, the anastomotic sites, the graft size and the graft type. We retrospectively reviewed the medical records of the patients. The total mean follow-up period was $29.4{\pm}13.1$ months. Result: The mean age was $65.95{\pm}9.61$ and there were 88 male patients. The most common clinical manifestation was ischemic resting pain in the lower extremities. The underlying combined diseases were hypertension (61%), diabetes (43%), cardiac problems (35%) and smoking (91.7%). The most frequent site of arterial obstruction was the superficial femoral artery (44 cases, 40%). A femoropopliteal artery bypass operation with a Polytetrafluoroethylene(PTFE) synthetic graft was done in 44 cases (40%) and the great saphenous vein graft was used in 11 cases. The postoperative ABI increased significantly from $0.30{\pm}0.11$ preoperatively to $0.63{\pm}0.11$ (p<0.001) postoperatively. In 8 cases, amputations above the ankle level were necessary. The graft patency rates were 86.4% and 68.0% after 1 and 3 years, respectively. There were 29 cases (30.21%) of patency failure; the male gender, smokers and hypertension were significantly more frequent in the failure group. Of these, hypertension was the most powerful risk factor (p=0.042). Conclusion: The arterial bypass operation is an effective treatment modality for controlling the symptoms such as pain and claudication, and for preventing major amputations for the patients with atherosclerotic arterial obstructive disease. This study suggests quitting smoking, strict blood pressure control, selection of an appropriate graft, regular outpatient follow up and proper medication would offer higher patency rates and more favorable outcomes.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.210-215
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• 2008

Background: Drug-eluting stents are contributing to the exponential growth of percutaneous coronary intervention, and even in the patients with left main coronary artery disease, owing to the decreased restenosis rate. Our study aimed at comparing the one-year results after coronary artery bypass grafting versus percutaneous coronary intervention with drug-eluting stents in patients with left main coronary artery disease. Material and Method: Those patients who underwent coronary bypass surgery or stenting at our hospital under the diagnosis of left main coronary artery disease were divided in two groups. The variables for comparison were the preoperative disease severity, the length of the hospital stay, the early mortality and the cumulative incidence of mortality, myocardial infarction and repeated revascularization. Result: There were 101 cases in the surgery group and 78 cases in the stent group. Age, gender, the risk factors, the left ventricular ejection fraction and the proportion of acute coronary syndrome showed no significant differences between the two groups. The surgery group showed a more severe condition according to the Euroscore, a greater incidence of urgency, a longer hospital stay and a greater incidence of multi-vessel disease. The early mortality and one-year cumulative mortality were not different between the groups. The Euroscore-matched comparison for the surgery group (41 patients) and the stent group (78 patients) showed no significant differences in the Euroscore, age, gender, risk factors and the proportion of acute coronary syndrome. The surgery group in the Euroscore-matched comparison showed more multi-vessel disease and a longer hospital stay. The surgery group showed lower early mortality and lower one-year cumulative mortality, but this was statistically insignificant (0% vs 2.6%, respectively, p=0.55; 0% vs 6.6%, respectively, p=0.30). The rates of repeated revascularization and major adverse events (death or myocardial infarct) were lower in the CABG group, but this was not statistically significant (13.3% vs 6.3%, respectively, p=0.48; 10.0% vs 0%, respectively, p=0.09). Conclusion: Percutaneous coronary intervention using drug-eluting stents in low-risk patients with left main coronary artery disease resulted in a shortened length of the hospital stay, as compared with that of the CABG group of patients. However, the patients who underwent percutaneous coronary intervention using drug-eluting stents showed a tendency for an increased rate of repeated revascularization and higher one-year cumulative mortality. Further studies with large populations and longer follow-up will be necessary to reaffirm our findings.

• Journal of Chest Surgery
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• v.39 no.3 s.260
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• pp.184-193
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• 2006

Background: Off-pump coronary artery bypass grafting (OPCAB) has been proven to result in less morbidity. The patients who have left ventricular dysfunction may have benefits by avoiding the adverse effects of the cardiopulmonary bypass. The present study compared early and midterm outcomes of off-pump versus on-pump coronary artery bypass grafting (On pump CABG) in patients with severe left ventricular dysfunction. Material and Method: Ninety hundred forth six patients underwent isolated coronary artery bypass grafting by one surgeon between January 2001 and Febrary 2005.. Data were collected in 100 patients who had left ventricular ejection fraction (L VEF) less than $35\%$ (68 OPCAB; 32 On pump CABG). Mean age of patients were 62.9$\pm$9.0 years in OPCAS group and 63.8$\pm$8.0 years in On pump CABG group. We compared the preoperative risk factors and evaluated early and midterm outcomes. Result: In OPCAB and On pump CABG group, mean number of used grafts per patient were 2.75$\pm$0.72, 2.78$\pm$0.55 and mean number of distal anastomoses were 3.00$\pm$0.79, 3.16$\pm$0.72 respectively. There was one perioperative death in OPCAB group ($1.5\%$). The operation time, ventilation time, ICU stay time, CK-MB on the first postoperative day, and occurrence rate of complications were significantly low in OPCAB group. Mean follow-up time was 26.6$\pm$12.8 months (4${\~}$54 months). Mean LVEF of OPCAB and On pump CABG group improved significantly from $27.1\pm4.5\%$ to $40.7\pm13.0\%$ and $26.9\pm5.4\%$ to $33.3\pm13.7\%$. The 4-year actuarial survival rate of OPCAB and On pump CABG group were $92.2\%,\;88.3\%$ and the 4-year freedom rates from cardiac death were $97.7\%,\;96.4\%$ respectively. There were no significant differences between two groups in 4 year freedom rate from cardiac event and angina. Conclusion: OPCAS improves myocardial function and favors early and mid-term outcomes in patients with severe left ventricular dysfunction compared to On pump CABG group. Therefore, OPCAB is a preferable operative strategy even in patients with severe left ventricular dysfunction.

• Journal of Chest Surgery
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• v.40 no.5 s.274
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• pp.351-355
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• 2007

Background: Postinfarction ventricular septal rupture is associated with mortality as high as $85\sim90%$, if it is treated medically. This report documents our experience with postinfarction ventricular septal rupture that was treated surgically, Material and Method: We retrospectively reviewed the medical records of 11 patients who were operated on due to postinfarction ventricular septal rupture between August 1996 and August 2006. There were 4 men and 7 women, with a mean age of $70{\pm}11$ years (age range: $50\sim84$ years). The location of the rupture was anterior in 7 cases and posterior in 4 cases. The interval between the onset of acute myocardial infarction and the occurrence of the ventricular septal rupture was $2.0{\pm}1.3$ days (range: $1\sim5$ days). Operation was performed at an average of $2.4{\pm}2.7$ days (range: $0\sim8$ days) after the diagnosis of septal rupture. Preoperative intraaortic balloon pump therapy was performed in 10 patients. Result: The infarct exclusion technique was used in all cases. Coronary artery bypass grafting was done in 8 cases, with the mean number of distal anastomosis being $1.0{\pm}0.8$. There was one operative death. In 2 patients, reoperation was performed due to a residual septal defect. The postoperative morbidities were transient atrial fibrillation (n=7), paroxysmal supraventricular tachycardia (n=1), low cardiac output syndrome (n=3), bleeding reoperation (n=2), delayed sternal closure (n=2), acute renal failure (n=2), pneumonia (n=1), intraaortic balloon pump-related thromboembolism (n=1), and transient delirium (n=2). Nine patients have been followed up for a mean of $38{\pm}40$ months except for one follow-up loss. There have been 3 late deaths. At the latest follow-up, all 6 survivors were in a good functional class. Conclusion: We demonstrated satisfactory operative and midterm results with our strategy of preoperative intraaortic balloon pump therapy, early repair of septal rupture by infarct exclusion and combined coronary revascularization.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.659-665
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• 2003

The aim of this study was to evaluate the early and midterm results of off-pump total arterial revascularization using the skeletonized right gastroepiploic artery (RGEA) as a third arterial conduit. Material and Method: We prospectively analyzed 103 patients who underwent off-pump total arterial revascularization using bilateral internal thoracic arteries (ITAS) and RGEA. The RGEA was used as in situ graft in 88 patients, composite graft in 10 patients, and free graft in 5 patients. Postoperative coronary angiographies were performed before discharge in 100 patients, and at postoperative one year in 88 patients. Result: The RGEA showed a significantly higher free flow (130$\pm$95 ml/min) than that of right ITA(113$\pm$57 ml/min) or left ITA (107$\pm$55 ml/min), which was measured before anastomosis (p < 0.05). The total number of distal anastomoses was 3.8$\pm$0.7. The number of distal anastomoses per bilateral ITAs was 2.8$\pm$0.7 and the number of distal anastomosis per RGEA was 1.0. There were two morialities including one operative mortality. The late mortality was not related to cardiac events. Early postoperative morbidities were atrial fibrillation in 15 patients, bleeding reoperation in 4 patients, mediastinitis in 1 patients, perioperative myocardial infarction in 2 patient, and transient ARF in 3 patients. Postoperative coronary angiographies showed the early patency rate of 98.6％ (272/276) for ITAs and 97.0％ (97/100) for RGEA, respectively (p=ns), and the one-year patency rate of 95.9％ (234/244) for ITAs and 88.6％ (78/88) for RGEA, respectively (p=0.07). Flow competition between the RGEA and NCA (native coronary artery) was seen in 5 of the 100 patients (5.0％) immediate postoperatively and 7 of the 88 patients (8.0％) 1 year after surgery. Since July, 2000, we measured transit time flow intraoperatively and could reduce flow competition significantly Conclusion: The skeletonized RGEA demonstrated excellent early and midterm patency rates and could be used as a third arterial graft following the bilateral ITAs.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.715-721
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• 1999

Background:The number of old patients receiving coronary artery bypass grafting(CABG) is increasing. With the more recent advances in operative techniques, the age at which CABG is indicated has also increased. This study evaluated the risk factors associated with the hospital mortality and the morbidity following CABG in elderly patients. Material and Method: Between March 1991 and June 1998, we retrospectively reviewed 45 consecutive patients aged 65 years or older who underwent CABG. We compared the data with the results of 179 patients under the age 65 years operated during the same period. Result: Mean age was 68${\pm}$1.41 years(range 65 to 74 years). Emergency surgery was required in 4, and elective surgery in 41 patients. The mean number of distal anastomosis per patient was 3.62 ${\pm}$0.81 and mean aortic cross-cramp time was 69.84${\pm}$18.5 minutes. Thirty patients had Canadian class III or IV preoperatively, but 43 patients had class I or II postoperatively. The left ventricular ejection fraction increased significantly from 54.23${\pm}$10.62% preoperatively to 58.14${\pm}$9.88% postoperatively(p<0.05). Postoperative complication was pneumonia in 2 patients, acute renal failure in 2 patients, sternal wound infection in 1 patient, and postoperative myocardial infarction in 1 patient. There were two postoperative deaths. The causes of deaths were low output syndrome in one patient, and sepsis due to pneumonia in the other patient. The hospital mortality was higher in the elderly group(4.4 versus 2.86%) but was not statistically significant(p>0.05). Incremental risk factors for hospital deaths in the elderly were emergent operation, preoperative PTCA, postoperative use of IABP and postoperative ARF(p<0.05). The duration of hospital stay after operation was significantly longer for the elderly group than the younger group(19.27${\pm}$12.51 vs 15.55${\pm}$6.99 days; p＜ 0.05). Follow-up was complete for 34 of the hospital survivors and ranged from 1 to 73 months(mean: 23.58${\pm}$19.56 months). There was no late mortality of cardiac origin. Conclusion: Age is an important factor in selecting optimal management for elderly patients with coronary compromise, but age alone should not dictate the choice of therapy. Coronary artery bypass surgery in the elderly is associated with acceptable early mortality and excellent long-term results.