Clinical and angiographic outcomes of bilateral internal thoracic artery revascularization: in situ versus free grafts.

BACKGROUND: Bilateral internal thoracic artery (ITA) grafting is associated with improved long-term outcomes; however, the appropriate graft configuration remains controversial. We compared the long-term outcomes of different graft configurations. METHODS: Between 2009 and 2015, 1171 patients underwent isolated bilateral ITA grafting for left-sided complete revascularization at 4 Japanese cardiac surgery centers: underwent in situ left ITA to the left anterior descending artery+in situ right ITA to the left circumflex artery (LR group, n=278), in situ right ITA to the left anterior descending artery+in situ left ITA to the left circumflex artery (RL group, n=665), and in situ left ITA to the left anterior descending artery+free right ITA to the left circumflex artery (Free group, n=228). Major adverse cardiovascular events (MACE), including mortality, myocardial infarction and revascularization, and ITA patency were compared. RESULTS: Among the 3 groups, the Free group showed significantly lower MACE and overall mortality rates (p<0.001). Nonfatal myocardial infarction and revascularization rates showed no marked differences among the groups. A weighted analysis revealed a decreased risk of MACE and death in the Free group. No marked difference was observed in the patency of the ITA anastomosed to the left anterior descending artery. Patency of the ITA grafted to the circumflex artery in the LR group was significantly lower relative to the other groups. Using a free RITA grafted to the circumflex artery reduced the risk of graft failure. CONCLUSIONS: The free RITA configuration for left-sided revascularization might have better long-term outcomes and significantly better patency than other grafts.

Effect of Left Ventricular Hyperenhancement in Magnetic Resonance Imaging on Reverse Remodeling After Mitral Valve Repair for Moderate Ischemic Mitral Regurgitation.

We aimed to investigate cardiac magnetic resonance imaging (MRI)-derived predictors of a lack of left ventricular (LV) reverse remodeling after undersized mitral annuloplasty (uMAP) for moderate ischemic mitral regurgitation (IMR). We retrospectively reviewed 31 patients who underwent uMAP for moderate IMR and cardiac MRI evaluation between 2004 and 2017. Cardiac MRI evaluation included cine MRI LV and right ventricular volumetric measurements and gadolinium-enhanced MRI assessment of myocardial scarring. LV dimensions were assessed preoperatively, postoperatively, and at follow-up using serial transthoracic echocardiography, and the mid-term (median, 49 months) predictors of a lack of LV reverse remodeling were analyzed. At the mid-term follow-up (mean follow-up period: 85 ± 40 months), 15 patients exhibited reverse LV remodeling. The relative reduction in LV dimension at follow-up was negatively correlated with the preoperative number of LV segments with myocardial infarction (MI) (defined as an LV segment with >25% enhancement). The optimal cut-off for predicting a lack of reverse LV remodeling at follow-up was >5 LV segments with MI, with a sensitivity and specificity of 92% and 92%, respectively. This cut-off value also predicted all-cause mortality at follow-up, with a sensitivity and specificity of 88% and 67%, respectively. The presence of >5 LV segments with MI on gadolinium-enhanced MRI might be a useful predictor of lack of reverse LV remodeling and all-cause mortality outcomes after undersized mitral annuloplasty for moderate IMR.

15-year outcomes of the JOCRI study (JOCRIED study): a randomised comparison of off-pump and on-pump multiple arterial coronary revascularisation.

OBJECTIVE: The Japanese Off-Pump Coronary Revascularization Investigation (JOCRI) study reported a non-significant difference in early outcomes and graft patency between off-pump coronary artery bypass grafting and on-pump coronary artery bypass grafting in 2005. The JOCRIED study aimed to review the long-term outcomes of the JOCRI study participants. METHOD AND RESULTS: The JOCRIED study enrolled 123 of the JOCRI study participants completing the clinical follow-up between August 2018 and August 2020; 61 patients in the off-pump group and 62 patients in the on-pump group. The follow-up period was 13.8 ± 2.8 years. The groups were compared regarding mortality, the incidence of major adverse cardiac and cerebrovascular events and repeat revascularisation. The 15-year cumulative survival rate (off-pump vs on-pump, respectively; 77.7% vs 75.3%; p = 0.85), major adverse events-free survival rate (62.5% vs 55.6%; p = 0.27) and repeat revascularisation-free rate (84.8% vs 78.0%; p = 0.16) were not significantly different between the two groups. Revascularisation was the most common major adverse events in the JOCRIED participants. Although percutaneous coronary intervention was performed in 8 patients (13%) in the off-pump group and in 14 patients (23%) in the on-pump group (p = 0.23), no patients underwent redo coronary artery bypass grafting. CONCLUSIONS: Off-pump coronary artery bypass grafting provides comparable 15-year outcomes to on-pump coronary artery bypass grafting.

Coronary artery bypass grafting for coronary artery anomalies in infants and young children.

OBJECTIVES: Coronary artery bypass grafting (CABG) has been reported for coronary artery diseases in patients with Kawasaki disease and coronary artery complications after arterial switch operations for transposition of the great arteries. However, only a few studies have explored this modality for congenital coronary artery anomalies. As congenital coronary artery anomalies, particularly left coronary artery atresia and stenosis, are one of the reasons for sudden death, coronary revascularization is often required in infants and young children. Therefore, we aimed to investigate the outcome of CABG for such anomalies in infants and young children. METHODS: From 2014 to 2018, 3 infants and 2 children (median age: 10 months; range: 6-40 months) with coronary artery anomalies underwent CABG at our hospital. The indications for the procedure included left main coronary artery atresia and stenosis in 2 and 3 patients, respectively. Graft patency was evaluated postoperatively by contrast-enhanced computed tomography or coronary angiography, and postoperative outcomes (including death and cardiac events) were assessed during the follow-up period. RESULTS: No 30-day or in-hospital mortalities were noted. Postoperative examinations revealed patent grafts in all patients. They were discharged without any cardiac complications. Regarding the outcomes at the follow-up period, the graft patency rate was 80.0% (4/5 grafts), with no deaths or cardiac events. CONCLUSIONS: CABG is a useful strategy for coronary revascularization in infants and young children with coronary artery anomalies. Although the mid-term outcomes and patency are satisfactory, careful follow-up is necessary because the long-term outcomes remain unknown.

Preoperative Left Ventricular Energy Loss in the Operating Theater Reflects Subjective Symptoms in Chronic Aortic Regurgitation.

BACKGROUND: There is currently no subjective, definitive evaluation method for therapeutic indication other than symptoms in aortic regurgitation. Energy loss, a novel parameter of cardiac workload, can be visualized and quantified using echocardiography vector flow mapping. The purpose of the present study was to evaluate whether energy loss in patients with chronic aortic regurgitation can quantify their subjective symptoms more clearly than other conventional metrics. METHODS: We studied 15 patients undergoing elective aortic valve surgery for aortic regurgitation. We divided the patients into symptomatic and asymptomatic groups using their admission records. We analyzed the mean energy loss in one cardiac cycle using transesophageal echocardiography during the preoperative period. The relationships between symptoms, energy loss, and other conventional metrics were statistically analyzed. RESULTS: There were seven and eight patients in the symptomatic and asymptomatic groups, respectively. The mean energy loss of one cardiac cycle was higher in the symptomatic group (121 mW/m [96-184]) than in the asymptomatic group (87 mW/m [80-103]) (p = 0.040), whereas the diastolic diameter was higher in the asymptomatic group (65 mm [59-78]) than in the symptomatic group (57 mm [51-57]) (p = 0.040). There was no significant difference between the symptomatic and asymptomatic groups in terms of other conventional metrics. CONCLUSIONS: An energy loss can quantify patients' subjective symptoms more clearly than other conventional metrics. The small sample size is the primary limitation of our study, further studies assessing larger cohort of patients are warranted to validate our findings.

Stress Echocardiography After Mitral Valve Repair Using a Semirigid Partial Band.

BACKGROUND: The reduction in exercise capacity after mitral valve repair (MVr) for severe degenerative mitral regurgitation is an unsolved issue. This study aimed to evaluate hemodynamics after MVr using a partial semirigid band during exercise stress echocardiography and to identify predictive factors for achieving better exercise capacity after MVr. METHODS: We retrospectively analyzed 48 patients using exercise stress echocardiography within 5 years of having undergone MVr using a partial semirigid band between 2013 and 2019. Values of maximal workload were converted into numbers of metabolic equivalents (METs) achieved for each patient. Age and sex expected METs (eMETs) were obtained, and percent eMETs (%eMETs [achieved METs / eMETs × 100]) were calculated. Multivariable linear regression analysis was used to identify the determinants of %eMETs. RESULTS: Only one third of patients achieved eMETs. Significant determinants of %eMETs were age at exercise stress echocardiography (ß coefficient 0.64; 95% confidence interval, 0.31 to 0.96; P < .001), female sex (ß coefficient 16.9; 95% confidence interval, 8.58 to 25.17; P < .001), and larger indexed device size (device size/body surface area; ß coefficient 4.10; 95% confidence interval, 1.74 to 6.46; P = .001). Receiver-operating characteristic curve analysis revealed that a cutoff value of 19.5 mm/m2 or greater indexed device size was optimal for achieving %eMETs greater than 100%, with a sensitivity and specificity of 87% and 79%, respectively. CONCLUSIONS: Patients with larger indexed device size achieved greater exercise capacity after MVr using a partial semirigid band. Preoperative evaluation to decide whether we can use an annuloplasty device larger than 19.5 mm/m2 may be important for patients who intend to exercise with high intensity.

Influences of mitral annuloplasty on left ventricular flow dynamics assessed with 3-dimensional cine phase-contrast flow magnetic resonance imaging.

OBJECTIVES: We assessed the influence of annuloplasty procedures in mitral repair on left ventricular (LV) vortex flow patterns and aortic outflow patterns, and flow energy loss (EL). METHODS: Twenty healthy volunteers and 14 patients who had undergone mitral valve repair were examined using 3-dimensional cine phase-contrast magnetic resonance imaging. A band group included 7 patients with semi-rigid and 2 with flexible partial bands. The ring group included 5 patients with semi-rigid complete rings. LV vortex flow patterns, aortic outflow patterns, EL, and aortic annulus changes during one cardiac cycle were evaluated. RESULTS: Mitral repair induced different vortex flow patterns compared with that of healthy volunteers. The vortex beneath the anterior mitral leaflet with semi-rigid devices was double-stranded in early diastole, and it was single-stranded with flexible bands with a large shift toward the apex during diastole. LVEL in patients who underwent mitral repair (0.84 ± 0.42 mW) was greater than that in healthy volunteers (0.47 ± 0.10 mW). Complete rings disturbed aortic outflow patterns, with EL distribution changes. Smaller devices relative to patient body size disturbed LV flow patterns and caused high EL. No significant relationship was found between indexed ring orifice area and transmitral mean pressure gradient (r = -0.25, P = .414), but a negative relationship exists between indexed ring orifice area and LVEL (r = -0.84, P < .001). CONCLUSIONS: Mitral repair, especially with relatively small annuloplasty rings, induced abnormal LV flow patterns and EL elevation, which have the potential to be a novel hemodynamic evaluation method after mitral repair.

Comparison of long-term outcomes between off-pump and on-pump coronary artery bypass grafting using Japanese nationwide cardiovascular surgery database.

OBJECTIVES: In Japan, off-pump coronary artery bypass (OPCAB) is more common than on-pump coronary artery bypass. Superior early results of OPCAB have been reported; however, long-term results were still unclear. Purpose of this study is to evaluate the clinical outcomes of OPCAB in Japan using Japan Adult Cardiovascular Surgery Database. METHODS: Between 2008 and 2010, 23,633 patients who underwent isolated coronary artery bypass were reported in database. We selected the cases from the hospital with mean annual coronary surgery volume of more than 50. Among the total of 7724 cases at 41 institutions, 2150 (31.2%) on-pump coronary artery bypass (ONCAB) and 5574 (68.8%) OPCAB cases were included. Propensity score (PS) matching was performed using PS developed from patient characteristics and preoperative factors resulting in 2007 cases matched pairs. Long-term follow-up data on patients' mortality and stroke were collected. RESULTS: In-hospital mortality was significantly lower in OPCAB (ONCAB 1.1%, OPCAB 0.4% p = 0.01). Stroke was low in OPCAB group (ONCAB 1.7%, OPCAB 0.8%, p = 0.01). There was no statistically significant difference between OPCAB and ONCAB regarding 7-year overall survival (86.1% vs 88.1% respectively), composite outcomes (72.0% vs 73.9% respectively), or cardiac deaths (97.3% vs 97.1% respectively). Subgroup analysis (more than 75 years old) showed a worse trend in OPCAB group. Only in OPCAB group, incomplete revascularization significantly influenced 7-year survival. CONCLUSIONS: OPCAB is associated with early prognostic benefits; however, it might be less favorable outcomes in the long term when patients are older or with incomplete revascularization.

[Valve Surgery after Coronary Artery Bypass Grafting].

It has been reported that there are some risks of coronary artery graft injury while redo sternotomy was required for valve surgery after coronary artery bypass grafting (CABG). Also it is well known that clinical results after graft injury was poor. For avoiding graft injury, coronary artery graft must be placed away from the sternum at the time of initial CABG. For redo sternotomy, 3-dimensional-computed tomography can be useful. For aortic valve surgery after CABG, treatment of patent in-situ graft have to be discussed. For common practice, dissecting and clamping the patent in-situ graft during cardiac arrest were required. However, there are some reports showing good clinical results with moderate hypothermia, non-dissection and non-clamping graft. Furthermore, less mobidity rate results of transcatheter aortic valve implantation( TAVI) after CABG was reported. For mitral valve surgery after CABG, right mini-thoracotomy was reported as preferred procedure recently. Dissection area could be reduced than re-median sternotomy, although clamping aorta and patent graft were technically difficult. Two procedures were reported such as hypothermia and ventricular fibrillation or normothermia and beating heart. MitraClip procedure can be considered for high risk patients. Newly developed surgical and catheter technique may change the strategy for heart valve disease after CABG.

Blood flow energy loss: a predictor for the recovery of left ventricular function after bioprosthetic aortic valve replacement.

OBJECTIVES: It is difficult to estimate the improvement in left ventricular (LV) function after aortic valve replacement (AVR). The present study aimed to evaluate whether energy loss (EL) can predict the postoperative LV function after AVR. METHODS: Nine patients who underwent AVR with a bioprosthetic valve were enrolled in the present study. Porcine prostheses were used in 5 patients and bovine pericardial prostheses were used in 4 patients. The aortic flow pattern was visualized and EL and cardiac output (CO) were measured using 4-dimensional flow magnetic resonance imaging from the LV to the descending aorta; the EL/CO ratio in the extracted area was calculated as total EL/CO ratio. RESULTS: With a porcine valve, a severe helical flow was observed in the ascending aorta during the holosystolic phase. In contrast, with a bovine pericardial valve, straight transvalvular aortic flow was observed in the early systolic phase and 2 large vortical flows occurred on both sides of the greater and lesser curvature of the ascending aorta after the mid-systolic period. The total EL/CO ratio was strongly correlated with LV ejection fraction improvement after AVR (r = 0.74, P = 0.02). CONCLUSIONS: The aortic flow pattern is different between the porcine valve and bovine pericardial valve. The total EL/CO ratio is a valuable tool for evaluating the postoperative LV ejection fraction improvement after AVR. Optimization of total EL/CO ratio would have potential to improve haemodynamic performances after AVR.

Prediction for future occurrence of type A aortic dissection using computational fluid dynamics.

OBJECTIVES: The actual underlying mechanisms of acute type A aortic dissection (AAAD) are not well understood. The present study aimed to elucidate the mechanism of AAAD using computational fluid dynamics (CFD) analysis. METHODS: We performed CFD analysis using patient-specific computed tomography imaging in 3 healthy control cases and 3 patients with AAAD. From computed tomography images, we made a healthy control model or pre-dissection model for CFD analysis. Pulsatile cardiac flow during one cardiac cycle was simulated, and a three-dimensional flow streamline was visualized to evaluate flow velocity, wall shear stress and oscillatory shear index (OSI). RESULTS: In healthy controls, the transvalvular aortic flow was parallel to the ascending aorta. There was no spotty high OSI area at the ascending aorta. In pre-dissection patients, accelerated transvalvular aortic flow was towards the posterolateral ascending aorta. The vortex flow was observed on the side of the lesser curvature in mid-systole and expanded throughout the entire ascending aorta during diastole. Systolic wall shear stress was high due to the accelerated aortic blood flow on the side of the greater curvature of the ascending aorta. On the side of the lesser curvature, high OSI areas were observed around the vortex flow. In all pre-dissection cases, a spotty high OSI area was in close proximity to the actual primary entry site of the future AAAD. CONCLUSIONS: The pre-onset high OSI area with vortex flow is closely associated with the future primary entry site. Therefore, we can elucidate the mechanism of AAAD with CFD analysis.

Extrathoracic Superior Vena Cava Bypass With Venous Return Cannulas in Malignant Mediastinal Tumor Surgery.

Combined resection of the superior vena cava is sometimes challenging during radical surgery for malignant mediastinal tumors. We report a case of a 21-year-old man with a malignant mediastinal germ cell tumor who underwent surgical resection with superior vena cava reconstruction involving an extrathoracic temporary bypass from the right brachiocephalic vein to the right atrium using a venous return cannula because of left brachiocephalic vein occlusion. This is a convenient and safe optional technique providing an excellent intrathoracic surgical view for temporary superior vena cava bypass in patients with invasive malignant mediastinal tumor associated with venous return through the hemilateral brachiocephalic vein.

Computational fluid dynamics of internal mammary artery-left anterior descending artery anastomoses.

OBJECTIVES: The aim of this study was to elucidate the remodelling of the internal mammary artery (IMA)-left anterior descending artery anastomosis and compare 2 different anastomosis techniques (end-to-side versus side-to-side) using computational fluid dynamics. METHODS: This study included 9 patients. Computed tomography (CT) angiography was performed immediately after coronary artery bypass grafting (CABG) and at 3-6 months later. The computational fluid dynamics models were made using the CT data. The pulsatile 3-dimensional blood flow was achieved with the finite volume method to evaluate the postoperative morphological and haemodynamic changes at the anastomosis in each patient. Flow velocity distribution, wall shear stress (WSS) and its fluctuation oscillatory shear index were measured. RESULTS: No early or mid-term graft occlusion was observed in the study series. In the side-to-side anastomosis, pouch formation at the distal end of IMA caused a vortex flow with low WSS immediately after CABG. However, at 3-6 months after surgery, this pouch disappeared. As a result, the laminar straight flow with uniform WSS distribution was achieved inside the anastomosis. In the end-to-side anastomosis, the anastomosis shape was remodelled, resulting in a laminar flow pattern with uniform WSS distribution. A patchy high oscillatory shear index was detected at the IMA wall on the top of anastomosis in either anastomosis techniques immediately after the surgery, but it disappeared at 3-6 months after surgery. CONCLUSIONS: Regardless of the anastomosis technique used, a successful remodelling of the IMA-left anterior descending artery anastomosis shape was achieved a few months after surgery, resulting in a straightforward flow streamline, with uniform WSS distribution and minimal oscillatory shear index.

Delayed patch repair of a ruptured mitral subvalvular pseudoaneurysm caused by infective endocarditis: a case report.

BACKGROUND: Ruptured subvalvular pseudoaneurysm is a rare but significantly fatal complication of infective endocarditis. We report a successful surgical case of ruptured subvalvular pseudoaneurysm with infective endocarditis. CASE SUMMARY: A 46-year-old man presenting with high fever was admitted to a local hospital. Physical examination revealed small erythema and petechiae on his lower limbs. Transthoracic echocardiogram did not show any visible vegetation and valvular disease; however, magnetic resonance imaging (MRI) showed multiple acute cerebral infractions, and methicillin-susceptible Staphylococcus aureus was detected in the blood culture. Infective endocarditis was suspected, and an antibacterial medication was initiated. Twelve days later, he suffered from a sudden cardiogenic shock due to cardiac tamponade. Bloody pericardial effusion (1600 mL) was drained, and his condition improved substantially. Transoesophageal echocardiography after pericardial drainage revealed severe mitral regurgitation and a subvalvular aneurysm at the posteromedial side of the mitral annulus; these were not detected at the time of admission. He was transferred to our hospital for surgery; however, since fresh cerebral bleeding was observed in MRI, the surgery was delayed. Three weeks later, after confirming that the blood culture was negative for any growth, patch repair of the subvalvular pseudoaneurysm and mitral valve repair were performed. Post-operatively, no complication or arrhythmia was observed; he was discharged 25 days later. DISCUSSION: We report a rare case of successful delayed surgery for a ruptured subvalvular pseudoaneurysm at the posteromedial side of the mitral annulus, which presented complications for infective endocarditis by S. aureus.

[Functional Mitral Stenosis after Mitral Valve Repair for Degenerative Mitral Valve Regurgitation].

Functional mitral stenosis after mitral valve repair for degenerative mitral regurgitation( DMR) is an evolving concept. Mitral annuloplasty devices stabilize the mitral annulus, reduce leaflet stress and increase leaflet coaptation, which leads to improvement of repair durability at the cost of dynamic and physiological annular movement and diastolic annular area. An elevation in rest and peak transmitral gradient has been observed in some patients with annuloplasty devices, and this elevation may associate with worse prognosis as late atrial fibrillation or lower functional capacity after surgery. In this review, we summarize the current reports describing functional mitral stenosis after mitral valve repair for DMR.

Surgical intervention for ischemic mitral regurgitation: how can we achieve better outcomes?

Ischemic mitral regurgitation (MR) is a common complication of myocardial infarction. Left ventricular (LV) dysfunction and distortion of the subvalvular apparatus are the main contributors to ischemic MR. Coronary artery bypass grafting alone, mitral valve replacement, and mitral valve repair, with or without subvalvular procedures, have been performed for moderate-to-severe ischemic MR. Several randomized studies on the surgical treatment of ischemic MR have been performed; however, the optimal surgical strategy remains controversial because none have demonstrated a clear survival benefit. Since the mechanisms of ischemic MR are complex and multifactorial, comprehensive preoperative assessment of LV function and geometry (both global and regional), mitral valve configuration, viability testing, and exercise echocardiography are needed. A better understanding of this complicated disease and of the advantages and limitations of each procedure may help us devise more effective patient-specific surgical treatment strategies and achieve better outcomes.

Coronary Arteriovenous Fistula Draining Into Persistent Left Superior Vena Cava.

A 75-year-old woman was referred to our hospital for dyspnea and edema of the lower limbs. Computed tomography angiography revealed a dilated left coronary artery from the left main trunk to the left circumflex branch and a dilated fistula originating from the left circumflex branch and draining into the persistent left superior vena cava. Physical examination revealed pulmonary hypertension and congestive heart failure. We performed closure of the fistula and left main coronary artery orifice and coronary artery bypass grafting. Postoperative computed tomography angiography showed patency of all grafts and progression of thrombosis in the dilated abnormal vessels.

Aortic Arch Pseudoaneurysm Associated With Chronic Trauma by Resected Edge of the Left Clavicle.

A 66-year-old man, who had a history of left lung and clavicle resection, was referred to us for aortic arch pseudoaneurysm. Resected edge of the left clavicle was attached to the anterior surface of the aortic arch. Patch repair of the pseudoaneurysm using hypothermic circulatory arrest was performed successfully. (Level of Difficulty: Intermediate.).