Early and Two-year Outcomes after Sutureless and Conventional Aortic Valve Replacement: a Nationwide Population-based Study

Background@#We compared early and 2-year clinical outcomes of sutureless aortic valve replacement (SAVR) with conventional aortic valve replacement (CAVR) in a nationwide study based on claims data. @*Methods@#From December 2016 to November 2018, 3,173 patients underwent bioprosthetic aortic valve replacements. SAVR and CAVR were performed in 641 and 2,532 patients, respectively. Propensity score-matched analysis was performed in 640 patient pairs. @*Results@#Operative mortality rate was 2.8% without significant differences between the SAVR (3.4%) and CAVR (2.3%) groups (P = 0.324). There were no significant differences in postoperative morbidities between the groups except for permanent pacemaker (PPM) implantation. PPM implantation rate was significantly higher in the SAVR (3.8%) than in the CAVR group (0.9%) (P < 0.001). One- and two-year overall survival was 89.1% and 87.5%, respectively, without significant differences between the groups (SAVR group vs. CAVR group = 89.9% and 90.5% vs. 87.2% and 88.7%, respectively; P = 0.475). There were no significant differences in the cumulative incidence of cardiac death, stroke, aortic valve reoperation and infective endocarditis between the groups. Cumulative PPM implantation incidence at 6 months in the CAVR was 1.1%, and no patient required PPM implantation after 6 months. In the SAVR, the cumulative PPM implantation incidence at 0.5, one, and two years was 3.9%, 5.0% and 5.6%, respectively. The cumulative PPM implantation rate was higher in the SAVR group than in the CAVR group (P < 0.001). @*Conclusion@#Early and 2-year clinical outcomes between SAVR and CAVR were not different except for a high rate of permanent pacemaker implantation in the SAVR group.

The Performance of the Current Risk Prediction Scoring Systems in Patients Undergoing Anaortic Off-pump Coronary Artery Bypass Grafting

Background@#This study aimed to evaluate the performance of the Society of Thoracic Surgeons (STS) risk model and European System for Cardiac Operative Risk Evaluation (EuroSCORE) II for patients undergoing anaortic off-pump coronary artery bypass grafting (OPCAB). @*Methods@#From January 2010 to June 2017, 1,048 patients (isolated anaortic OPCAB: 1,043, on-pump conversion:5) undergoing isolated anaortic OPCAB were enrolled. The STS risk score and EuroSCORE II were calculated with dedicated online software. Calibration of the models were performed by the risk-adjusted event ratio that was defined as observed events divided by expected events (O/E ratio) and Hosmer-Lemeshow test. The discrimination powers were evaluated by the area under the receiver operating characteristic curve (AUC). @*Results@#Operative mortality occurred in 10 patients (0.95%). The predicted mortality rates by the EuroSCORE II and STS risk model were 2.58 ± 4.15% and 1.72 ± 2.92%, respectively. The O/E ratio of the EuroSCORE II was 0.370 with significant overprediction of operative mortality (confidence interval [CI], 0.157–0.652; P = 0.003). The STS score also overpredicted the operative mortality (O/E ratio, 0.556) with marginal significance (CI, 0.266–1.023; P = 0.052). Permanent stroke occurred in 6 patients (0.53%). The predicted permanent stroke occurrence rate was 1.73 ± 1.48%. The O/E ratio was 0.332 with significant overprediction of permanent stroke (CI, 0.121–0.722; P = 0.011). Regarding discrimination power for the STS risk model, the operative mortality was excellent (AUC, 0.876) and permanent stroke was acceptable (AUC, 0.740). The EuroSCORE II showed good discrimination power (AUC, 0.784). There was a significant difference in discrimination power for mortality between STS and EuroSCORE II risk models (P = 0.007). @*Conclusion@#Preexisting risk predicting scoring systems, STS risk model and EuroSCORE II, overpredict the risk of mortality and stroke rate for anaortic OPCAB. These findings suggest the possibility that anaortic OPCAB can lower the operative mortality and occurrence of postoperative stroke than conventional coronary artery bypass grafting.

Early and Two-year Outcomes after Sutureless and Conventional Aortic Valve Replacement: a Nationwide Population-based Study

Background@#We compared early and 2-year clinical outcomes of sutureless aortic valve replacement (SAVR) with conventional aortic valve replacement (CAVR) in a nationwide study based on claims data. @*Methods@#From December 2016 to November 2018, 3,173 patients underwent bioprosthetic aortic valve replacements. SAVR and CAVR were performed in 641 and 2,532 patients, respectively. Propensity score-matched analysis was performed in 640 patient pairs. @*Results@#Operative mortality rate was 2.8% without significant differences between the SAVR (3.4%) and CAVR (2.3%) groups (P = 0.324). There were no significant differences in postoperative morbidities between the groups except for permanent pacemaker (PPM) implantation. PPM implantation rate was significantly higher in the SAVR (3.8%) than in the CAVR group (0.9%) (P < 0.001). One- and two-year overall survival was 89.1% and 87.5%, respectively, without significant differences between the groups (SAVR group vs. CAVR group = 89.9% and 90.5% vs. 87.2% and 88.7%, respectively; P = 0.475). There were no significant differences in the cumulative incidence of cardiac death, stroke, aortic valve reoperation and infective endocarditis between the groups. Cumulative PPM implantation incidence at 6 months in the CAVR was 1.1%, and no patient required PPM implantation after 6 months. In the SAVR, the cumulative PPM implantation incidence at 0.5, one, and two years was 3.9%, 5.0% and 5.6%, respectively. The cumulative PPM implantation rate was higher in the SAVR group than in the CAVR group (P < 0.001). @*Conclusion@#Early and 2-year clinical outcomes between SAVR and CAVR were not different except for a high rate of permanent pacemaker implantation in the SAVR group.

The Performance of the Current Risk Prediction Scoring Systems in Patients Undergoing Anaortic Off-pump Coronary Artery Bypass Grafting

Background@#This study aimed to evaluate the performance of the Society of Thoracic Surgeons (STS) risk model and European System for Cardiac Operative Risk Evaluation (EuroSCORE) II for patients undergoing anaortic off-pump coronary artery bypass grafting (OPCAB). @*Methods@#From January 2010 to June 2017, 1,048 patients (isolated anaortic OPCAB: 1,043, on-pump conversion:5) undergoing isolated anaortic OPCAB were enrolled. The STS risk score and EuroSCORE II were calculated with dedicated online software. Calibration of the models were performed by the risk-adjusted event ratio that was defined as observed events divided by expected events (O/E ratio) and Hosmer-Lemeshow test. The discrimination powers were evaluated by the area under the receiver operating characteristic curve (AUC). @*Results@#Operative mortality occurred in 10 patients (0.95%). The predicted mortality rates by the EuroSCORE II and STS risk model were 2.58 ± 4.15% and 1.72 ± 2.92%, respectively. The O/E ratio of the EuroSCORE II was 0.370 with significant overprediction of operative mortality (confidence interval [CI], 0.157–0.652; P = 0.003). The STS score also overpredicted the operative mortality (O/E ratio, 0.556) with marginal significance (CI, 0.266–1.023; P = 0.052). Permanent stroke occurred in 6 patients (0.53%). The predicted permanent stroke occurrence rate was 1.73 ± 1.48%. The O/E ratio was 0.332 with significant overprediction of permanent stroke (CI, 0.121–0.722; P = 0.011). Regarding discrimination power for the STS risk model, the operative mortality was excellent (AUC, 0.876) and permanent stroke was acceptable (AUC, 0.740). The EuroSCORE II showed good discrimination power (AUC, 0.784). There was a significant difference in discrimination power for mortality between STS and EuroSCORE II risk models (P = 0.007). @*Conclusion@#Preexisting risk predicting scoring systems, STS risk model and EuroSCORE II, overpredict the risk of mortality and stroke rate for anaortic OPCAB. These findings suggest the possibility that anaortic OPCAB can lower the operative mortality and occurrence of postoperative stroke than conventional coronary artery bypass grafting.

Initial Experience with Epicardial Ultrasound Scanning in Coronary Artery Bypass Grafting

Background@#The benefits of epicardial ultrasound scanning (EUS) in coronary artery bypass grafting (CABG) have not yet been established. The aim of this study was to evaluate the usefulness of EUS in CABG, including in the assessment of the quality of distal anastomoses, the identification of epicardial target vessels, and the evaluation of any graft issues other than the distal anastomoses. @*Methods@#Fifty-three patients undergoing CABG were enrolled between March 2018 and February 2019. Intraoperative EUS was performed along with transit-time flow measurement (TTFM). Graft evaluations were performed early (shortly after surgery) and 1 year after surgery for 53 (100%) and 47 (88.7%) patients, respectively. @*Results@#EUS was applied to assess the quality of all distal anastomoses, 32 target vessels, and 2 conduit trunks. Insufficient TTFM findings were obtained for 18 grafts. However, graft revision was performed for only 3 distal anastomoses; based on the EUS findings, the remaining 15 sites were not revised. The early and 1-year overall graft patency rates were 100% (141 anastomoses) and 96.1% (122 of 127 anastomoses), respectively. All 15 of the distal anastomoses that were not revised despite insufficient TTFM results were patent at the 1-year mark. @*Conclusion@#The routine application of EUS in CABG could be beneficial by confirming the quality of surgery and reducing unnecessary procedures.

Hemodynamic Performance of Pericardial Bioprostheses in the Aortic Position

Background@#This study was conducted to evaluate the hemodynamic performance and the incidence of prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) using bovine pericardial valves (Carpentier-Edwards Perimount Magana and Magna Ease). @*Methods@#In total, 216 patients (mean age, 70.0±10.5 years) who underwent AVR using stented bovine pericardial valves and had follow-up echocardiography between 3 months and 2 years (mean, 12.0±6.6 months) after surgery were enrolled. The implanted valve sizes were 19, 21, 23, and 25 mm in 32, 56, 99, and 29 patients, respectively. @*Results@#On follow-up echocardiography, the mean transvalvular pressure gradients for the 19-mm, 21-mm, 23-mm, and 25-mm valves were 13.3±4.4, 12.6±4.2, 10.5±3.9, and 10.2± 3.7 mm Hg, respectively. The effective orifice area (EOA) was 1.25±0.26, 1.54±0.31, 1.81±0.41, and 1.87±0.33 ㎠ , respectively. These values were smaller than those suggested by the manufacturer for the corresponding sizes. No patients had PPM, when based on the reference EOA. However, moderate (EOA index ≤0.85㎠ /㎡ ) and severe (EOA index ≤0.65 ㎠ /㎡ ) PPM was present in 56 patients (11.8%) and 9 patients (1.9%), respectively, when using the measured values. @*Conclusion@#Carpentier-Edwards Perimount Magna and Magna Ease bovine pericardial valves showed satisfactory hemodynamic performance with low rates of PPM, although the reference EOA could overestimate the true EOA for individual patients.

Safety and Efficacy of Left Atrial Appendage Excision Using a Vascular Stapler

Background@#This study was conducted to evaluate the safety and efficacy of left atrial appendage (LAA) excision using a vascular stapler. @*Methods@#Fifty consecutive patients (mean age, 68±9 years) who underwent LAA excision using a vascular stapler during concomitant cardiac surgery were enrolled. In all patients, the excision site was evaluated using computed tomography at a median of 7 days (interquartile range, 5–13.3 days) postoperatively. The safety endpoint of this study was the occurrence of LAA excision-related events, which were defined as bleeding from the excision site that required reinforcement sutures or reoperation due to excision site bleeding. The efficacy endpoint was LAA excision failure, which was defined as a remnant LAA (a stump >1 cm in maximum length) or extravasation of radiocontrast dye. @*Results@#LAAs were excised using 60- and 45-mm vascular staplers in 49 patients and 1 patient, respectively. Reinforcement sutures were needed in 4 patients due to staple-line bleeding and in 4 patients due to bleeding of the surrounding tissues. No patient underwent reoperation due to staple-related bleeding. A remnant LAA was observed in 2 patients, while extravasation of radiocontrast dye was not observed in any patients. @*Conclusion@#LAA excision using a vascular stapler may be an effective technique for LAA exclusion. Delicate handling of the stapler device and LA tissue is required to prevent procedure- related complications.

Early Surgery versus Watchful Waiting in Patients with Moderate Aortic Stenosis and Left Ventricular Systolic Dysfunction

Background and Objectives@#Severe aortic stenosis (AS) with left ventricular systolic dysfunction (LVSD) is a class I indication for aortic valve replacement (AVR) but this recommendation is not well established in those at the stage of moderate AS. We investigate the clinical impact of AVR among patients with moderate AS and LVSD. @*Methods@#From 2001 to 2017, we consecutively identified patients with moderate AS and LVSD, defined as aortic valve area 1.0–1.5 cm2 and left ventricular ejection fraction <50%. The primary outcome was all-cause death. The outcomes were compared between those who underwent early surgical AVR (within 2 years of index echocardiography) at the stage of moderate AS versus those who were followed medically without AVR at the outpatient clinic. @*Results@#Among 255 patients (70.1±11.3 years, male 62%), 37 patients received early AVR. The early AVR group was younger than the medical observation group (63.1±7.9 vs. 71.3±11.4) with a lower prevalence of hypertension and chronic kidney disease. During a median 1.8-year follow up, 121 patients (47.5%) died, and the early AVR group showed a significantly lower all-cause death rate than the medical observation group (5.03PY vs. 18.80PY, p<0.001). After multivariable Cox-proportional hazard regression adjusting for age, sex, comorbidities, and laboratory data, early AVR at the stage of moderate AS significantly reduced the risk of death (hazard ratio, 0.43; 95% confidence interval 0.20–0.91; p=0.028). @*Conclusions@#In patients with moderate AS and LVSD, AVR reduces the risk of all-cause death. A prospective randomized trial is warranted to confirm our findings.

Optimal Tricuspid Annular Size for Tricuspid Annuloplasty in Patients with Less-Than-Moderate Functional Tricuspid Regurgitation

Background@#We evaluated the association between tricuspid annular dilatation and the development of moderate or severe tricuspid regurgitation (TR). Additionally, we determined the optimal tricuspid annular dilatation threshold to use as an indicator for tricuspid annuloplasty in patients with less-than-moderate functional TR (FTR). @*Methods@#Between August 2007 and December 2014, 227 patients with less-than-moderate TR underwent mitral valve surgery without a tricuspid valve (TV) procedure. The TV annular diameter was measured via transthoracic echocardiography. The TV annular index (TVAI) was calculated as the TV annular diameter divided by the body surface area.The mean duration of echocardiographic follow-up was 42.0 months (interquartile range, 9.3–66.6 months). @*Results@#Eight patients (3.5%) developed moderate or severe TR. The rate of freedom from development of moderate or severe TR at 5 years was 96.2%. TV annular diameter, left atrial diameter, preoperative atrial fibrillation, and TVAI were found to be associated with the development of moderate or severe TR in the univariate analysis. A cut-off TVAI value of 19.8 mm/㎡ was found to predict the development of moderate or severe TR, and a significant difference was observed in the development of TR of this severity based on this cut-off (p<0.001). @*Conclusion@#The progression of TR was not infrequent in patients with untreated lessthan-moderate FTR. An aggressive treatment approach can be helpful to prevent the progression of FTR for patients with risk factors, especially TVAI greater than 19.8 mm/m 2 .

Frailty Index is Associated with Adverse Outcomes after Aortic Valve Replacement in Elderly Patients

BACKGROUND: This study was conducted to evaluate the prognostic value of the frailty index based on routine laboratory data (FI-L) in elderly patients who underwent surgical aortic valve replacement (SAVR). METHODS: A total of 154 elderly patients (≥ 75 years) (78.7 ± 3.6 years; men:women = 78:76) who underwent aortic valve replacement with stented bioprosthesis between 2001 and 2018 were enrolled. The FI-L was calculated as the proportion of abnormal results out of 32 items based on laboratory tests, pulse rate and blood pressure. The primary outcome was all-cause mortality. Secondary outcomes included operative mortality and aortic valve-related events (AVREs) during follow-up. The predictive values of FI-L for the early and late outcomes were evaluated using logistic regression and Cox proportional hazards models, respectively. The median follow-up duration was 40 months (interquartile, 15–74). RESULTS: The operative mortality rate was 3.9% (n = 6). Late death occurred in 29 patients. The overall survival (OS) rates at 5, 10, and 15 years were 83.3%, 59.0%, and 41.6%, respectively. The AVREs occurred in 28 patients and the freedom rates from AVREs at 5, 10, and 15 years were 79.4%, 72.7%, and 52.9%, respectively. Multivariable analyses demonstrated that FI-L was a significant factor for OS (hazard ratio, 1.075; 95% confidence interval, 1.040–1.111). A minimal P value approach showed that a FI-L of 25% was the best cutoff value to predict OS after SAVR. CONCLUSION: The FI-L is significantly associated with early and long-term outcomes after SAVR in elderly patients. Frailty rather than a patient's age should be considered in the decision-making process for SAVR in elderly patients.

Comparison of the Plasma Metabolome Profiles Between the Internal Thoracic Artery and Ascending Aorta in Patients Undergoing Coronary Artery Bypass Graft Surgery Using Gas Chromatography Time-of-Flight Mass Spectrometry

BACKGROUND: The left internal thoracic artery (LITA) has been used as the first conduit of choice in coronary artery bypass grafting (CABG) because of excellent long-term patency and outcomes. However, no studies have examined substances other than nitric oxide that could be beneficial for the bypass conduit, native coronary artery or ischemic myocardium. This study was conducted to evaluate differences in metabolic profiles between the LITA and ascending aorta using gas chromatography-time of flight-mass spectrometry (GC-TOF-MS). METHODS: Twenty patients who underwent CABG using the LITA were prospectively enrolled. Plasma samples were collected simultaneously from the LITA and ascending aorta. GC-TOF-MS based untargeted metabolomic analyses were performed and a 2-step volcano plot analysis was used to identify distinguishable markers from two plasma metabolome profiles. Semi-quantitative and quantitative analyses were performed using GC-TOF-MS and enzyme-linked immunosorbent assay, respectively, after selecting target metabolites based on the metabolite set enrichment analysis. RESULTS: Initial volcano plot analysis demonstrated 5 possible markers among 851 peaks detected. The final analysis demonstrated that the L-cysteine peak was significantly higher in the LITA than in the ascending aorta (fold change = 1.86). The concentrations of intermediate metabolites such as L-cysteine, L-methionine and L-cystine in the ‘cysteine and methionine metabolism pathway' were significantly higher in the LITA than in the ascending aorta (2.0-, 1.4- and 1.2-fold, respectively). Quantitative analysis showed that the concentration of hydrogen sulfide (H2S) was significantly higher in the LITA. CONCLUSION: The plasma metabolome profiles of the LITA and ascending aorta were different, particularly higher plasma concentrations of L-cysteine and H2S in the LITA.

Surgical Treatment of Degenerative Mitral Valve Regurgitation in the Elderly: Comparison of Early and Long-Term Outcomes Using Propensity Score Matching Analysis

BACKGROUND: It is unclear whether mitral valve (MV) repair for degenerative mitral regurgitation (MR) provides the same advantages in the elderly that it does in the general population. METHODS: From 1994 to 2016, 188 elderly patients (mean age, 68.3±5.50 years) underwent MV repair (n=153) or MV replacement (n=35) for primary degenerative MR. Early and long-term outcomes were compared before and after propensity score matching (PSM). RESULTS: Before PSM, there was a significant difference in operative mortality (p=0.011). Overall survival and freedom from cardiac-related death (CRD) at 5, 10, and 15 years were significantly higher in patients who underwent MV repair (p=0.039 and p=0.007, respectively). In the multivariable analysis, MV replacement was an independent risk factor of CRD. After PSM, operative mortality was not significantly lower in patients who underwent MV repair (p=0.125). Overall survival and freedom from CRD at 5, 10, and 15 years showed no significant difference between the 2 groups in the PSM cohort (p=0.207, p=0.47, respectively). There was no significant difference in freedom from reoperation before or after PSM (p=0.963 and p=0.575, respectively). CONCLUSION: MV repair for primary degenerative MR might be a valid option in the elderly population if successful repair is possible.

Aortic Valve Replacement for Aortic Stenosis in Elderly Patients (75 Years or Older)

BACKGROUND: This study evaluated the early and long-term outcomes of surgical aortic valve replacement (AVR) in elderly patients in the era of transcatheter aortic valve implantation. METHODS: Between 2001 and 2018, 94 patients aged ≥75 years underwent isolated AVR with stented bioprosthetic valves for aortic valve stenosis (AS). The main etiologies of AS were degenerative (n=63) and bicuspid (n=21). The median follow-up duration was 40.7 months (range, 0.6–174 months). RESULTS: Operative mortality occurred in 2 patients (2.1%) and paravalvular leak occurred in 1 patient. No patients required permanent pacemaker insertion after surgery. Late death occurred in 11 patients. The overall survival rates at 5 and 10 years were 87.2% and 65.1%, respectively. The rates of freedom from valve-related events at 5 and 10 years were 94.5% and 88.6%, respectively. The Society of Thoracic Surgeons (STS) score (p=0.013) and chronic kidney disease (p=0.030) were significant factors affecting long-term survival. The minimal p-value approach demonstrated that an STS score of 3.5% was the most suitable cut-off value for predicting long-term survival. CONCLUSION: Surgical AVR for elderly AS patients may be feasible in terms of early mortality and postoperative complications, particularly paravalvular leak and permanent pacemaker insertion. The STS score and chronic kidney disease were associated with long-term outcomes after AVR in the elderly.

Minimally Invasive Redo Mitral Valve Replacement under Fibrillatory Arrest in a Patient with a Calcified Aorta and Patent Previous Bypass Grafts

A 73-year-old woman who underwent combined bioprosthetic mitral valve replacement, tricuspid ring annuloplasty, and coronary artery bypass grafting 12 years previously visited our clinic due to aggravated dyspnea caused by structural valve deterioration of the mitral prosthesis. Because aortic or femoral artery cannulation and cross-clamping would have a high risk of stroke owing to severe calcification of the ascending aorta and ilio-femoral vessels, and because there was a risk of redo sternotomy due to the patent bypass grafts, a comprehensive approach including axillary artery cannulation, a minimally invasive right thoracotomy approach, and a clampless hypothermic fibrillatory arrest technique was used during redo mitral valve replacement.

Early Clinical Outcomes of Tricuspid Valve Repair with a Tri-Ad Annuloplasty Ring in Comparison with the Outcomes Using an MC³ Ring

BACKGROUND: We evaluated the early clinical outcomes of tricuspid valve annuloplasty (TAP) with the Tri-Ad annuloplasty ring for functional tricuspid regurgitation (TR). METHODS: From January 2015 to March 2017, 36 patients underwent TAP with a Tri-Ad ring for functional TR. To evaluate the early clinical outcomes of TAP with the Tri-Ad ring, we conducted a propensity score-matched analysis comparing the Tri-Ad and MC3 tricuspid annuloplasty rings (n=34 in each group). The follow-up duration was 11.0±7.07 months. RESULTS: There was 1 case of operative mortality (2.8%) and no cases of late mortality. Postoperative complications occurred in 15 patients (41%), including acute kidney injury in 6 patients (16%), bleeding requiring reoperation in 4 patients (11%), and low cardiac output syndrome in 4 patients (11%). There were no ring-related complications, such as atrioventricular block or ring dehiscence. The TR grade decreased significantly (from 2.03±1.06 to 1.18±0.92, p < 0.01), as did the systolic pulmonary artery pressure (from 43.53±13.84 to 38.00±9.72 mm Hg, p=0.03). There were no cases of severe residual TR, but moderate TR was observed in 3 patients, all of whom had severe TR preoperatively. Severe preoperative TR was also associated with moderate in the univariate analysis (p < 0.01). In the propensity score-matched analysis comparing the Tri-Ad and MC3 rings, there was no significant difference in early clinical outcomes. CONCLUSION: TAP with the Tri-Ad ring corrected functional TR effectively and provided good early clinical and echocardiographic results without ring-related complications. However, severe preoperative TR was associated with moderate or severe residual TR in the immediate postoperative period. A follow-up study is necessary to confirm the stability of this procedure.

Extra-Anatomic Ascending Aorta to Abdominal Aorta Bypass in Takayasu Arteritis Patients with Mid-Aortic Syndrome

BACKGROUND: We evaluated the operative outcomes of an extra-anatomic bypass from the ascending aorta to the abdominal aorta in patients with type II or III Takayasu arteritis (TA) with mid-aortic syndrome. METHODS: From 1988 to 2014, 8 patients with type II (n=2) or III (n=6) TA underwent an ascending aorta to abdominal aorta bypass. The mean patient age was 43.5±12.2 years and the mean peak pressure gradient between the upper and lower extremities was 54.8±39.0 mm Hg. The median follow-up duration was 54.4 months (range, 17.8 to 177.4 months). RESULTS: There were no cases of operative mortality. The mean peak pressure gradient significantly decreased to −2.4±32.3 mm Hg (p=0.017 compared to the preoperative value). Late death occurred in 2 patients. The symptoms of upper extremity hypertension and claudication improved in all patients. The bypass grafts were patent at 47.1±58.9 months in 7 patients who underwent follow-up imaging studies. CONCLUSION: An extra-anatomic ascending aorta to abdominal aorta bypass could be an effective treatment option for severe aortic steno-occlusive disease in patients with type II or III TA, with favorable early and long-term outcomes.

Cardiac Magnetic Resonance Predictor of Ventricular Function after Surgical Coronary Revascularization

We evaluated echocardiographic changes of left ventricular (LV) function in coronary artery bypass grafting (CABG) patients with LV dysfunction, and examined cardiac magnetic resonance (CMR) parameters associated with improved LV function. Seventy-seven CABG patients presenting with decreased LV ejection fraction (LVEF, ≤ 35%) and who underwent preoperative gadolinium-enhanced CMR were enrolled. A 16-segment model was used to analyze CMR imaging. A viable myocardial segment was defined as ≤ 50% transmural extent of late gadolinium enhancement. Serial echocardiographic examinations were performed preoperatively, pre-discharge (median 6 days), and during postoperative year 1 (median 11 months) in 70 patients. Predictors of absolute increase in LVEF (≥ 5%) and proportional changes in LVEF were analyzed. Serial echocardiography demonstrated that LVEF measured 28.6% ± 5.4% preoperatively, 31.5% ± 8.0% median 6 days, and 42.1% ± 10.5% median 11 months postoperatively. Absolute increase of LVEF was observed in 27 patients at pre-discharge and in 24 patients by median 11 months. Proportional changes in LVEF at postoperative median 6 days and 11 months were 14% ± 28% and 57% ± 45%, respectively. The median number of viable myocardial segments was 14 (range, 9–16) in the 16 segment CMR model. Multivariable models demonstrated that the median number of overall viable myocardial segments (≥ 14) in preoperative CMR was associated with absolute increase (P = 0.046) and proportional changes (P = 0.005) in LVEF. In conclusion, the number of viable myocardial segments (≥ 14) in preoperative CMR predicted LV function improvement after CABG in patients with LV dysfunction.

Twenty-Year Experience of Heart Transplantation: Early and Long-Term Results

BACKGROUND: We evaluated early and long-term results after heart transplantation (HTPL). METHODS: One hundred five consecutive patients (male:female=80:25) who underwent HTPL between 1994 and 2013 were enrolled. Based on the changes in immunosuppressive regimen, the study patients were divided into two groups. Early and long-term clinical outcomes were evaluated and compared between the patients who underwent HTPL before (group E, n=41) and after July 2009 (group L, n=64). The group L patients were older (p<0.001), had higher incidence of hypertension (p=0.001) and chronic kidney disease (p<0.001), and more frequently needed preoperative mechanical ventilation (p=0.027) and mechanical circulatory support (p=0.014) than the group E patients. RESULTS: Overall operative mortality was 3.8%, and postoperative morbidities included acute kidney injury (n=31), respiratory complications (n=16), reoperation for bleeding (n=15) and wound complications (n=10). There were no significant differences in early results except acute kidney injury between group E and group L patients. Overall survival rates at 1, 5, and 10 years were 83.8%, 67.7%, and 54.9%, respectively, with no significant difference between the two patient groups. Rejection-free rates at 1 and 5 years were 63.0% and 59.7%, respectively; rates were significantly higher in group L than in group E (p<0.001). CONCLUSION: Despite increased preoperative comorbidities, group L patients showed similar early and long-term outcomes and significantly higher rejection-free rates when compared with group E patients.

Surgical Results of Third or More Cardiac Valve Operation

BACKGROUND: We evaluated operative outcomes after third or more cardiac operations for valvular heart disease, and analyzed whether pericardial coverage with artificial membrane is helpful for subsequent reoperation. METHODS: From 2000 to 2012, 149 patients (male:female=70:79; mean age at operation, 57.0+/-11.3 years) underwent their third to fifth operations for valvular heart disease. Early results were compared between patients who underwent their third operation (n=114) and those who underwent fourth or fifth operation (n=35). Outcomes were also compared between 71 patients who had their pericardium open during the previous operation and 27 patients who had artificial membrane coverage. RESULTS: Intraoperative adverse events occurred in 22 patients (14.8%). Right atrium (n=6) and innominate vein (n=5) were most frequently injured. In-hospital mortality rate was 9.4%. Total cardiopulmonary bypass time (225+/-77 minutes vs. 287+/-134 minutes, p=0.012) and the time required to prepare aortic cross clamp (209+/-57 minutes vs. 259+/-68 minutes, p<0.001) increased as reoperations were repeated. However, intraoperative event rate (13.2% vs. 20.0%), in-hospital mortality (9.6% vs. 8.6%) and postoperative complications were not statistically different according to the number of previous operations. Pericardial closure using artificial membrane at previous operation was not beneficial in reducing intraoperative events (25.9% vs. 18.3%) and shortening operation time preparing aortic cross clamp (248+/-64 minutes vs. 225+/-59 minutes) as compared to no-closure. CONCLUSION: Clinical outcomes of the third or more operations for valvular heart disease were acceptable in terms of intraoperative adverse events and in-hospital mortality rates. There were no differences in the incidence of intraoperative adverse events, early mortality and postoperative complications between third cardiac operation and fourth or more.

Efficacy of Cox Maze IV Procedure Using Argon-Based Cryoablation: A Comparative Study with N2O-Based Cryoablation

BACKGROUND: We compared the mid-term results of the Cox maze IV procedure using argon-based cryoablation with a procedure using N2O-based cryoablation. METHODS: From May 2006 to June 2012, 138 patients (mean age, 58.2+/-11.0 years) underwent the Cox maze IV procedure. Eighty-five patients underwent the maze procedure using an N2O-based cryoprobe (group N), and 53 patients underwent the maze procedure using an argon-based cryoprobe (group A). Bipolar radiofrequency ablation was concomitantly used in 131 patients. The presence of atrial fibrillation immediately, 6 months, 1 year, and 2 years after surgery was compared. RESULTS: Early mortality occurred in 6 patients (4.3%). There were no differences in early mortality or postoperative complications between the two groups. Nineteen of 115 patients (16.5%) remained in atrial fibrillation at postoperative 12 months (14 of 80 patients (17.5%) in group N and 5 of 35 patients (14.3%) in group A, p=0.669). There were no differences in the number of patients who remained in atrial fibrillation at any of the time periods except in the immediate postoperative period. A multivariable analysis revealed that the energy source of cryoablation was not associated with the presence of atrial fibrillation at 1 year (p=0.862) and that a fine F wave (<0.1 mV) was the only risk factor predicting the presence of atrial fibrillation at 1 year (p<0.001, odds ratio=20.287). CONCLUSION: The Cox maze IV procedure using an argon-based cryoprobe was safe and effective compared with the maze procedure using an N2O-based cryoprobe in terms of operative outcomes and the restoration of sinus rhythm for up to 2 years after surgery.