The appearance of new accessory pathway after the Cone procedure.

INTRODUCTION: Acquired Wolff-Parkinson-White (WPW) syndrome can occur after congenital heart disease (CHD) surgery. METHODS AND RESULTS: A 27-year-old male with Ebstein's anomaly and manifest WPW syndrome received catheter ablation twice. The first electrophysiology study (EPS) induced orthodromic atrioventricular reentrant tachycardia and successfully eliminated the posteroseptal accessory pathway (AP). Six months after the Cone procedure, the patient suffered from palpitation. The second EPS was performed and abolished the right lateral AP. CONCLUSION: The appearance of a new AP after the reconstruction of CHD is a rare finding and should raise suspicion of an acquired AP connection.

Implantation of monocusp valve prolongs the duration of chest tube drainage in children with tetralogy of fallot after corrective surgery.

BACKGROUND: Right ventricular outflow tract obstruction relief is one of the major procedures during the total correction of tetralogy of Fallot (TOF). Pulmonary insufficiency (PI) is usually inevitable after a transannular incision with a patch repair is performed. Therefore, some surgeons advocate to place a monocusp valve within the transannular patch (TAP) in order to decrease the severity of the PI. However, the monocusp valve seemed not be very effective in some patients who underwent the complete TOF repair. METHODS: Patients who had the classic form of TOF between January 2009 and January 2017 and underwent the corrective surgery with a TAP by the same cardiovascular surgeon were identified for further analysis. Clinical information including demographics at operation, perioperative data, and postoperative outcome were collected retrospectively and compared between the group with and without a monocusp valve. RESULTS: A total of 24 TOF cases were included in the final analysis, and 16 (66.7%) patients received a monocusp valve placement. The patients' characteristics before and during the surgery were similar between the two groups. The median duration of chest tube drainage after the total correction in the monocusp group was longer than those without the valve (p = 0.04). There was no difference in the immediate postoperative data, including the inflammation/infection status, the duration of mechanical ventilation, and the length of ICU and hospital stay. CONCLUSION: Implantation of a monocusp valve during the total TOF correction using a TAP did not bring benefit to improve the immediate postoperative outcomes, especially the duration of the pleural drainage. Further study with a prospective design and a larger number of cases is needed.

Diagnosis and Surgical Outcomes of Patients with Anomalous Left Coronary Artery from the Pulmonary Artery: A Single Taiwanese Medical Center Experience.

BACKGROUND: Anomalous left coronary artery from the pulmonary artery (ALCAPA), a very rare congenital cardiac anomaly, is associated with a high mortality rate among infants who are not diagnosed or treated in a timely manner. Surgical intervention with the reconstruction for a two-coronary-system circulation is the main treatment; however, there have been very few reported cases from Taiwan. In this study, we aim to describe the clinical manifestations, diagnostic methods, surgery types, and surgical outcomes in patients with ALCAPA from a single Taiwanese medical center. METHODS: We retrospectively reviewed patients diagnosed with ALCAPA who underwent surgery at our institution between January 2001 and October 2018. Clinical presentations, noninvasive and invasive study results, surgical methods, and postoperative follow-up results were assessed from medical records. Moreover, literature on this particular cardiovascular anomaly was reviewed. RESULTS: The study included 6 patients (5 children and 1 adult). The diagnosis was confirmed using cardiac catheterization and coronary angiography in four patients and only echocardiography in two patients. All patients underwent surgical correction and survived. Four patients showed improvements in left ventricular function and mitral regurgitation (MR). CONCLUSION: Early diagnosis and timely surgical intervention could avoid mortality regardless of the method of operation. ALCAPA can be definitively diagnosed using noninvasive echocardiography. Both left ventricular systolic function and mitral insufficiency could improve after the surgical intervention in pediatric patients. Repair or replacement of the mitral valve could be reserved for persistent MR complicated with congestive heart failure, particularly in patients who received the initial operation beyond infancy.

Preclinical evaluation of a pediatric airway stent for tracheobronchomalacia.

OBJECTIVES: We sought to demonstrate in an animal model that helical stents made from a nickel titanium alloy called nitinol (NiTi) and designed for malacic airways could be delivered and removed without significant trauma while minimally impeding mucus clearance during the period of implantation. METHODS: Stents were delivered and removed from the tracheas of healthy 20 kg swine (n = 5) using tools designed to minimize trauma. In 4-week experiments, the stents were implanted on day 0, removed after 3 weeks, and swine were put to death after 4 weeks. Weekly bronchoscopies, radiographs, and mucus clearance examinations were performed in vivo. Hematoxylin and eosin staining and scanning electron microscopy imaging were used to evaluate foreign body response, tracheal tissue reaction, and damage and to measure unciliated regions. RESULTS: In all in vivo experiments, the stent was implanted and removed atraumatically. Mucus clearance was maintained throughout the experiment period. Hematoxylin and eosin-stained slides showed that foreign body response and tracheal tissue damage were localized to the stented subsections. Tracheal tissue reaction and damage was further restricted to the epithelium and submucosal layers. Scanning electron microscopy imaging revealed that the cilia were absent only over the contact area between the trachea and the wire forming the helical stent. CONCLUSIONS: Helical nitinol stents designed to provide radial support for malacic airways were well tolerated in a porcine model, providing for mucus clearance while also enabling atraumatic removal.

A combination of tracheoplasty and tracheal stenting is an acceptable method of treating severe congenital tracheobronchial stenosis under extracorporeal membrane oxygenation.

BACKGROUND: Congenital tracheobronchial stenosis (CTBS) is a rare congenital condition characterized by complete cartilage rings covering varying lengths of the major airway. In this study, we reviewed the outcomes of patients with CTBS receiving surgical tracheoplasty in our institute. METHODS: We retrospectively analyzed the outcomes of consecutive patients with CTBS operated between 2006 and 2017 when extracorporeal membrane oxygenation (ECMO) was used perioperatively. RESULTS: In total, 11 patients (median follow-up period, 4.2 years; interquartile range, 1.6-5.4) were included. Seven were symptomatic in the neonatal period, 10 had cardiorespiratory anomalies, 7 required preoperative bronchoscopic balloon dilatation, and 1 required preoperative stent placement. Slide tracheoplasty (STP) was performed in 9 patients, and 2 underwent pericardial patch tracheoplasty. Seven patients required postoperative balloon dilatation, and 6 required postoperative stent placement. Early stenting provided immediate ventilatory improvement in all patients and facilitated successful extubation in a median of 4 days after stenting in 80% of the patients. CONCLUSIONS: Under ECMO, severe CTBS could be successfully treated through a combination of tracheoplasty and bronchoscopic management. STP provided excellent results for solitary trachea stenosis with a minimum diameter of ≥3 mm. In selected patients, postoperative tracheobronchial stent placement was crucial in minimizing the ECMO duration and facilitating extubation. LEVEL OF EVIDENCE: IV.

Long-term Surgical Prognosis of Primary Supravalvular Aortic Stenosis Repair.

BACKGROUND: Supravalvular aortic stenosis (SVAS) represents a heterogeneous group, including Williams syndrome, familial elastin arteriopathy, sporadic cases, and others. This study sought to evaluate long-term outcomes of SVAS repair. METHODS: A total of 87 patients underwent surgical repair of congenital SVAS at Boston Children's Hospital in Boston, Massachusetts, between 1997 and 2017. A total of 41 patients had Williams syndrome, and 46 did not. Of the 46 patients who did not have Williams syndrome, 23 had sporadic SVAS, and 13 had familial elastin arteriopathy. Demographic data and outcomes were reviewed and analyzed from medical records. RESULTS: The median age at operation was 2.9 years. Mean z score of the sinotubular junction was -3.29 ± 1.42 and of the aortic root was -0.09 ± 1.19. A total of 26% (n = 22) patients had coronary ostium stenosis, and 41% (n = 9) of them required patch plasty. Survival rates at 5, 10, and 20 years were all 94.3%. Freedom from left ventricular outflow tract reoperation at 5, 10, and 20 years was 78.5%, 70.3%, and 70.3%, respectively. Freedom from aortic arch reintervention at 5, 10, and 20 years was 98.6%, 94.3%, 89.3%, respectively. In risk factors analysis, age younger than 1 year, z scores of the aortic valve and aortic root, and concomitant right ventricular outflow tract surgical repair were predictive of the need for reoperation and reintervention for left or right ventricular outflow tract obstruction. CONCLUSIONS: Excellent long-term survival rates can be achieved with surgical repair of SVAS. Age younger than 1 year, small aortic valve and aortic root z scores, and concomitant right ventricular outflow tract surgical repair were predictors of reoperation and reintervention.

Optically-guided instrument for transapical beating-heart delivery of artificial mitral chordae tendineae.

OBJECTIVE: We sought to develop an instrument that would enable the delivery of artificial chordae tendineae (ACT) using optical visualization of the leaflet inside the beating heart. METHODS: A delivery instrument was developed together with an ACT anchor system. The instrument incorporates an optically clear silicone grasping surface in which are embedded a camera and LED for direct leaflet visualization during localization, grasping, and chordal delivery. ACTs, comprised of T-shaped anchors and an expanded polytetrafluoroethylene chordae, were fabricated to enable testing in a porcine model. Ex vivo experiments were used to measure the anchor tear-out force from the mitral leaflets. In vivo experiments were performed in which the mitral leaflets were accessed transapically using only optical guidance and ACTs were deployed in the posterior and anterior leaflets (P2 and A2 segments). RESULTS: In 5 porcine ex vivo experiments, the mean force required to tear the anchors from the leaflets was 3.8 ± 1.2 N. In 5 porcine in vivo nonsurvival procedures, 14 ACTs were successfully placed in the leaflets (9 in P2 and 5 in A2). ACT implantation took an average of 3.22 ± 0.83 minutes from entry to exit through the apex. CONCLUSIONS: Optical visualization of the mitral leaflet during chordal placement is feasible and provides direct feedback to the operator throughout the deployment sequence. This enables visual confirmation of the targeted leaflet location, distance from the free edge, and successful deployment of the chordal anchor. Further studies are needed to refine and assess the device for clinical use.

An Imaging Protocol to Discriminate Specialized Conduction Tissue During Congenital Heart Surgery.

We performed preclinical validation of intraoperative fiber-optic confocal microscopy (FCM) and assessed its safety and efficacy in an ovine model of the pediatric heart. Intraoperative imaging was performed using an FCM system (Cellvizio, Mauna Kea Technology, Paris, France) with specialized imaging miniprobe (GastroFlex UHD, Mauna Kea Technologies). Before imaging, we applied an extracellular fluorophore, sodium fluorescein, to fluorescently label extracellular space. We imaged arrested hearts of ovine (1-6 months) under cardiopulmonary bypass. Image sequences (1-10 seconds duration) were acquired from regions of the sinoatrial and atrioventricular node, as well as subepicardial and subendocardial working myocardium from atria and ventricle. The surgical process was evaluated for integration of the imaging protocol during the operative procedure. In addition, fluorescein cardiotoxicity studies (n = 3 animals) were conducted by comparing electrocardiogram (PR and QRS intervals) and ejection fraction at baseline and after topical application of fluorescein at 1:10, 1:100, and 1:1000 dilutions on a beating ovine heart. Our studies suggest that intraoperative FCM can be used to identify regions associated with specialized conducting tissue in ovine hearts in situ. The imaging protocol was integrated with conventional open heart surgical procedures with minimal changes to the operative process. Application of fluorescein in varying concentrations did not affect the normalized PR interval, QRS interval, and ejection fraction. These preclinical validation studies demonstrated both safety and efficacy of the proposed intraoperative imaging approach. The studies constitute an important step toward first-in-human clinical trials.

Relationship between the extent of aortic replacement and stent graft for acute DeBakey type I aortic dissection and outcomes: Results from a medical center in Taiwan.

BACKGROUND: Total arch replacement (TAR) and/or stent graft implantation has been proposed as the primary surgical treatment for acute DeBakey type I aortic dissection. However, the suggestion was based on excellent outcomes of high-volume or aortic centers. How about the real results in most places around the world? The purpose of this study was intended to compared in-hospital mortality, major complications, and aortic remodeling between TAR and/or stent graft implantation in a medical center of northern Taiwan. METHODS: Between January 2008 and August 2017, 156 patients with acute type I aortic dissection underwent surgery at our institution, including proximal aortic replacement only (Group I, n = 72), concomitant TAR (Group II, n = 23), concomitant TAR extended with stent grafting (Group III, n = 45), and proximal aortic replacement with descending aortic stent grafting (Group IV, n = 16). RESULTS: No significant differences were found in underlying disease and preoperative presentations, including operative risk among four groups. Overall in-hospital mortality was 22.4% (13 patients in Group I, 9 in Group II, 12 in Group III, and 1 in Group IV). New-onset stroke occurred in 15 patients postoperatively (3 patients [5.2%] in Group I, 3 [21.4%] in Group II, and 9 [26.5%] in Group III after excluding 36 patients with documented preoperative cerebrovascular accident or cerebral malperfusion). Root reconstruction and TAR were significantly associated with in-hospital mortality. TAR was significantly associated with surgery-related stroke. Compared to those in Group I, true lumen expansion and false lumen shrinkage during 1-year aortic remodeling were significantly higher in Groups III and IV. Both TAR and descending aorta stent grafting were significantly associated with decreased risk of patent false lumen. CONCLUSIONS: Proximal aortic replacement remains the preferred surgical strategy for acute type I aortic dissection, with lower mortality and neurological complications. Proximal descending aorta stent grafting may benefit aortic remodeling, even without TAR.

Preconditioning threshold of brief pressure overload of the left ventricle.

BACKGROUND: We previously reported that pressure overload of the left ventricle reduced myocardial infarct (MI) size in rabbits. The threshold of pressure overload was investigated in this study. METHODS: Pressure overload of the left ventricle was induced by partial snare of the ascending aorta in anesthetized, open-chest rabbits. Systolic left ventricular pressure (SLVP) was elevated 50% or 30% above baseline value by varying the degree of partial snaring. Different duration of pressure overload, including 10 minutes, 5 minutes, 3 minutes, or 2 minutes, was applied to determine the threshold of protective effects. Ischemic preconditioning was elicited by two 10-minute coronary artery occlusions and reperfusions. Ten minutes after different pretreatment, 1 hour occlusion of the left anterior descending coronary artery followed by 3 hours reperfusion was done to induce MI. The size of area at risk and MI were determined by blue dye injection and triphenyl tetrazolium chloride staining after experiments. RESULTS: Pressure overload increase of SLVP 50% above baseline value for 10 minutes, 5 minutes, and 3 minutes significantly reduced MI size (18.5 ± 3.6%, 21.4 ± 1.9% and 21.6 ± 1.7%, respectively, vs. 26.6 ± 1.0% in the control group, mean ± standard deviation, p < 0.01). A 30% increase of SLVP by pressure overload for 10 minutes, 5 minutes and 3 minutes also significantly decreased MI size (20.5 ± 2.5%, 21.6 ± 2.3%, and 21.5 ± 2.3%, p < 0.01). Ischemic preconditioning significantly decreased MI size (19.9 ± 2.8%, p < 0.001). Pressure overload to elevate SLVP 50% or 30% above baseline value for 2 minutes did not significantly alter MI size (25.0 ± 2.3% and 26.0 ± 1.7%, p = 0.122 and p = 0.457). Two episodes of 2 minutes pressure overload did not significantly decrease MI size (25.0 ± 2.2% and 25.5 ± 2.2%, p = 0.118 and p = 0.281). The hemodynamics, area at risk, and mortality were not significantly different among all groups of animals. CONCLUSION: Pressure overload to raise SLVP either 50% or 30% above baseline value reduced MI size. A minimum duration of 3 minutes was necessary to induce the protective effects.

Comparing peripheral blood stem cell collection using the COBE Spectra, Haemonetics MCS+, and Baxter Amicus.

Peripheral blood stem cells (PBSC) have become the most common source of hematopoietic cells for allogeneic or autologous blood and marrow transplantation (BMT). We performed an evaluation of PBSC collections using three different apheresis systems in two major transplantation centers in Singapore. Patients undergoing autologous BMT and donors collecting for allogeneic BMT were harvested using the COBE Spectra, Haemonetics MCS+, or Baxter Amicus. There were 99 Spectra collections (61 were autologous), 81 MCS+ collections (35 were autologous) and 38 Amicus collections (33 were autologous). Our data shows that the Amicus not only processed larger peripheral blood volumes but also yielded larger PBSC volume (P-value<0.05). In terms of PBSC products, the Spectra produced more WBC, WBC/liter blood processed, and WBC/kg (P-value<0.05). The Spectra and MCS+ produced comparable amount of CD34+ cells. Amicus collected 50% less platelets compared to Spectra and MCS+. The total CD34+ cells in the PBSC products was linearly correlated to the circulating CD34+ cells using Spectra, MCS+, and Amicus. Our results suggest that, compared to MCS+ and Amicus, collecting PBSC using the COBE Spectra can produce more WBC with a similar number of CD34+ cells. With a linear correlation of circulating CD34+ cells to the total CD34+ cells in the products, the availability of an automated procedure, no rotating seal, and a small extracorporeal volume, the Spectra appears to be the preferred machine for PBSC collection.

Optimization of human corneal endothelial cells for culture: the removal of corneal stromal fibroblast contamination using magnetic cell separation.

The culture of human corneal endothelial cells (CECs) is critical for the development of suitable graft alternative on biodegradable material, specifically for endothelial keratoplasty, which can potentially alleviate the global shortage of transplant-grade donor corneas available. However, the propagation of slow proliferative CECs in vitro can be hindered by rapid growing stromal corneal fibroblasts (CSFs) that may be coisolated in some cases. The purpose of this study was to evaluate a strategy using magnetic cell separation (MACS) technique to deplete the contaminating CSFs from CEC cultures using antifibroblast magnetic microbeads. Separated "labeled" and "flow-through" cell fractions were collected separately, cultured, and morphologically assessed. Cells from the "flow-through" fraction displayed compact polygonal morphology and expressed Na(+)/K(+)ATPase indicative of corneal endothelial cells, whilst cells from the "labeled" fraction were mostly elongated and fibroblastic. A separation efficacy of 96.88% was observed. Hence, MACS technique can be useful in the depletion of contaminating CSFs from within a culture of CECs.

Cultivation of human corneal endothelial cells isolated from paired donor corneas.

Consistent expansion of human corneal endothelial cells (hCECs) is critical in the development of tissue engineered endothelial constructs. However, a wide range of complex culture media, developed from different basal media have been reported in the propagation of hCECs, some with more success than others. These results are further confounded by donor-to-donor variability. The aim of this study is to evaluate four culture media in the isolation and propagation of hCECs isolated from a series of paired donor corneas in order to negate donor variability. Isolated primary hCECs were cultured in four previously published medium coded in this study as: M1-DMEM; M2-OptiMEM-I; M3-DMEM/F12, & M4-Ham's F12/M199. Primary hCECs established in these conditions were expanded for two passages and analyzed for (1) their propensity to adhere and proliferate; (2) their expression of characteristic corneal endothelium markers: Na+K+/ATPase and ZO-1; and (3) their cellular morphology throughout the study. We found that hCECs isolated in all four media showed rapid attachment when cultured on FNC-coated dishes. However, hCECs established in the four media exhibited different proliferation profiles with striking morphological differences. Corneal endothelial cells cultured in M1 and M3 could not be propagated beyond the first and second passage respectively. The hCECs cultured in M2 and M4 were significantly more proliferative and expressed markers characteristics of human corneal endothelium: Na+K+/ATPase and ZO-1. However, the unique morphological characteristics of cultivated hCECs were not maintained in either M2 or M4 beyond the third passage.The proliferative capacity and morphology of hCECs are vastly affected by the four culture media. For the development of tissue engineered graft materials using cultured hCECs derived from the isolation methodology described in this study, we propose the use of proliferative media M2 or M4 up to the third passage, or before the cultured hCECs lose their unique cellular morphology.

Early outcome of endovascular repair for contained ruptured abdominal aortic aneurysm.

BACKGROUND: Endovascular aneurysm repair (EVAR) has become a well-established technique in the treatment of elective surgery for abdominal aortic aneurysms (AAAs) due to proven benefits in mortality, hospital stay and operation time compared to open repair. The aim of this study was to report our experience in establishing the treatment protocol for EVAR of contained ruptured abdominal aortic aneurysms (rAAAs) and to illustrate the real impact of endovascular rAAA repair on surgical strategy. METHODS: Eighteen patients underwent AAA between January 2008 and October 2009. Six of them were enrolled in our study. The inclusion criteria were contained rAAA and the same anatomic consideration as in elective EVAR cases. The implant material was the Zenith AAA modular bifurcated device. Computed tomography (CT) scan was obtained in all patients pre-operatively and used as a follow-up tool. RESULTS: The mean age was 81 years (range 79-87 years). The procedural time was 259 ± 146 minutes, the maximal diameter of aneurismal sac was 8.4 ± 1.8 cm, and the pre-operative hemoglobin was 9.0 ± 1.2 mg/dL. The mean intensive care unit (ICU) stay was 10.5 ± 15 days. There was no surgical or in-hospital mortality. Complications included abdominal compartment syndrome, renal failure, wound infection and pneumonia. The mean follow-up period was 22 (range 19-29) months, with satisfactory result. CONCLUSION: Endovascular repair of rAAAs is feasible, and short-term results are promising, especially for contained and hemodynamic subgroup patients. It is indicated for elder patients with severe underlying diseases. Good logistics and adequate training of physicians or staff in an elective setting are prerequisites for this type of treatment program.

Left ventricular aneurysm repair: a comparison of linear versus patch remodeling.

BACKGROUND: Surgical repair of left ventricular (LV) aneurysm has been performed for around 50 years. However, the most appropriate surgical approach remains undetermined. This study was undertaken to compare the efficacy of 2 established techniques, linear versus patch remodeling, for repair of dyskinetic LV aneurysms. METHODS: We retrospectively reviewed the records of 49 patients (mean age, 69.8 +/- 7.3 years) who had operation for postinfarction dyskinetic LV aneurysm between 1996 and 2006. Thirty-one patients underwent patch remodeling and 18 underwent linear repair. Short-term and mid-term outcomes, including complications, cardiac function and mortality, were assessed. RESULTS: Overall inhospital surgical mortality, major complications and early hemodynamics showed no significant differences between the 2 groups. During a mean follow-up of 44.0 +/- 34.4 months, 8 patients died, with 4 due to cardiac-related causes. Actuarial survival rates at 1, 5 and 10 years were 85.7%, 69.9% and 45.7%, respectively. Functional class improved from 2.51 +/- 0.59 to 1.66 +/- 0.54 among the mid-term survivors (p < 0.001), with no significant difference between the 2 groups. Multivariate analysis identified preoperative NYHA functional class >or= 3 as an independent risk factor for overall mortality (p = 0.008). Mid-term follow-up revealed that LV ejection fraction improved from 26.5 +/- 7.2% to 34.1 +/- 7.9% (p < 0.001) in the patch group, and from 26.3 +/- 9.0% to 32.0 +/- 9.2% in the linear group (p = 0.032). In contrast, right ventricular ejection fraction improved from 49.4 +/- 10.1% to 52.0 +/- 7.3% (p = 0.190) in the patch group, but deteriorated from 55.0 +/- 6.3% to 50.3 +/- 8.6% in the linear group (p = 0.029). CONCLUSION: These findings indicate that the 2 repair techniques have similar effectiveness with respect to short- and mid-term outcomes except for right ventricular ejection fraction. We suggest that the selection of repair technique for LV aneurysms should be individualized for each patient based on aneurysm size and extent of the scarring process into the septum and subvalvular mitral apparatus.

Banding technique for endovascular repair of arch aneurysm with unsuitable proximal landing zone.

BACKGROUND: Endovascular repair of thoracic aortic aneurysms is an attractive alternative to surgical graft replacement, but many patients are excluded because of unsuitable proximal landing zones wider than 38 mm in diameter. Arch aneurysms can be repaired with less invasive hybrid surgery, combining endovascular stent grafting with banding of the proximal landing aorta. METHODS AND RESULTS: Since November 2006, 6 of 88 patients underwent hybrid aortic arch repair with presumptive zone 0 as the proximal landing site where the median maximal diameter was 42.5 mm (from 39 to 44 mm). After partial sternotomy, relocation of the supra-aortic branches, the ascending aorta was banded with a 2-layer Dacron strip and reduced to 36+/-1 mm in diameter where the stent graft was inserted and incorporated securely. All patients were uncomplicated, with complete exclusion of the arch lesion and without endoleaks or migration during an average 9 months' follow-up. CONCLUSIONS: Secure fixation of an unsuitable ascending aorta can be solved via aortic banding and will not only improve the short-term stability of the endovascular intervention, but may become the preferred therapeutic modality in patients with multiple comorbidities.

Coronary artery bypass grafting in patients with left ventricular dysfunction.

BACKGROUND: Coronary artery bypass grafting surgery (CABG) remains a challenge for patients with coronary artery disease and left ventricular (LV) dysfunction. The aim of this study was to evaluate the result of CABG in patients with LV dysfunction. METHODS: Medical records of 1,847 patients who underwent primary, isolated CABG at Taipei Veterans General Hospital from January 1, 1991 to December 31, 2002, were reviewed. The mortality rate associated with clinical and operative variables was compared between patients with LV ejection fraction (LVEF) > or = 35% and patients with LVEF < 35%. RESULTS: Patients with LVEF < 35% had more episodes of myocardial infarction (57.5% vs 28.9%, p < 0.001) and history of congestive heart failure (18.1% vs 3.2%, p < 0.001), higher New York Heart Association (NYHA) class, and higher angina class. Longer cardiopulmonary bypass time (147 +/- 44 minutes vs 137 +/- 40 minutes, p < 0.001) but fewer left internal mammary artery (LIMA) grafts (46.8% vs 65.7%, p < 0.001) were used in patients with LVEF < 35%. Patients with LVEF < 35% had significantly higher hospital mortality (6.6% vs 2.2%, p < 0.001), higher major morbidity (23.3% vs 16.1%, p < 0.01), and longer hospital stay (25 +/- 23 days vs 21 +/- 16 days, p < 0.01). CONCLUSION: Although patients with LV dysfunction had higher mortality and morbidity, CABG could be done in these high-risk patients with acceptable results.