Mid-term outcomes of right ventricular papillary muscle approximation for severe functional tricuspid regurgitation.

OBJECTIVES: Recurrence of tricuspid regurgitation (TR) after tricuspid annuloplasty can occur in cases where a dilated right ventricle exists and subsequent leaflet tethering follows. We previously reported a new technique of the right ventricular papillary muscle approximation (RV-PMA) for functional TR associated with leaflet tethering. The objective of this study is to elucidate the mid-term outcomes and evaluate the durability of RV-PMA. METHODS: Between January 2014 and March 2023, we applied RV-PMA in 20 patients of advanced functional TR with severe leaflet tethering. The indication of the technique was severe TR with leaflet tethering height >8 mm, and/or a right ventricular end-diastolic diameter >45 mm. The patients were followed up with echocardiography before discharge and at annual interval thereafter. RESULTS: There was no perioperative mortality. In the echocardiography performed before discharge, TR was decreased to mild or less in 85%, and a significant improvement in right ventricular end-diastolic diameter and tethering height were achieved (53-45 mm and 11.1-4.4 mm, respectively). Furthermore, during the median 3-year follow-up period, TR was kept controlled mild or less in 80% of the cases. CONCLUSIONS: RV-PMA is considered to be a safe, effective and durable technique as an additional approach for tricuspid annuloplasty.

Descriptive analysis of long-term survival after aortic valve replacement for dialysis patients: importance of renal pathologies and age.

OBJECTIVES: This study analyzed the long-term survival of dialysis patients undergoing AVR using the Japanese National Clinical Database with additional survival data. METHODS: De-novo AVR for dialysis-dependent patients between 2010 and 2012 who were registered in the Japan Cardiovascular Surgery Database were included. Concomitant aortic surgery and transcatheter aortic valve replacement were excluded. An additional questionnaire was sent to each hospital regarding the underlying kidney disease, the duration of dialysis initiation to the surgery, and clinical outcomes. The Kaplan-Meier survival curve was descriptively shown for all cohorts and each renal pathology. Furthermore, we compared the incidence of bioprosthetic valve failure in patients who were < 65 years old (group Y) and ≧65 years old (group O). RESULTS: Of these 1529 patients, diabetic nephropathy was 517, chronic glomerulonephritis was 437, and renal sclerosis was 210, regarding renal pathology. 1, 3, and 5-year survival in each pathology was 78.4%, 58.6%, 45.9% in diabetic nephritis, 78.8%, 68.4%, 58.2% in chronic glomerulonephritis, 79.0%, 67.8%, 52.1% in renal sclerosis, and 74.4%, 62.6%, 49.2% in others. Active infectious endocarditis was more prevalent in group Y (O 2.7% vs. Y 9.6%). The incidence of bioprosthetic valve failure requiring re-hospitalization was too small to analyze. 1, 3, and 5-year survival was 76.0%, 63.4%, 49.2% in group O and 74.3%, 64.2%, and 47.7% in group Y. CONCLUSIONS: Long-term survival of AVR for dialysis-dependent was higher in patients with chronic glomerulonephritis and lower in patients with diabetic nephritis than in other pathologies.

Extracellular Volume Fraction by Computed Tomography Predicts Prognosis After Transcatheter Aortic Valve Replacement.

BACKGROUND: Extracellular volume fraction (ECV) on magnetic resonance imaging can predict prognosis after aortic valve replacement in patients with aortic stenosis (AS). However, the usefulness of ECV on computed tomography (CT) for patients who have undergone transcatheter aortic valve replacement (TAVR) is unclear, so we investigated whether ECV analysis on CT is associated with clinical outcomes in TAVR candidates.Methods and Results: We analyzed 127 patients with severe AS who underwent preoperative CT for TAVR. We evaluated the utility of ECV analysis on single-energy CT for predicting patient prognosis after TAVR. The primary outcome was a composite of all-cause death and hospitalization due to heart failure (HF) after TAVR. 15 patients (12%) had composite outcomes: 4 deaths and 11 hospitalizations due to HF. In multivariate survival analysis using the Cox proportional hazard model, atrial fibrillation (AF) (hazard ratio (HR), 7.86; 95% confidence interval (CI), 2.57-24.03; P<0.001), history of congestive HF (HR, 4.91; 95% CI, 1.49-16.2; P=0.009) and ECV ≥32.6% on CT (HR, 6.96; 95% CI, 1.92-25.12; P=0.003) were independent predictors of composite outcomes. On Kaplan-Meier analysis, the higher ECV group (≥32.6%) had a significantly greater number of composite outcomes than the lower ECV group (P<0.001). CONCLUSIONS: ECV on CT is an independent predictor of prognosis after TAVR.

Annular rupture during transcatheter aortic valve replacement in a long-term corticosteroid user: a case report.

A 74-year-old woman with a history of interstitial pneumonia, who had been taking oral corticosteroids for the past 9 years, was diagnosed with severe aortic stenosis. The patient underwent transfemoral transcatheter aortic valve replacement (TAVR) with a balloon-expandable valve under local anesthesia. After deploying a 26-mm SAPIEN 3 valve with 1.5 ml less balloon inflation, transesophageal echocardiography revealed a hemorrhage in the aortic annulus. Intraoperative angiography revealed a small contrast leakage around the ascending aorta. Emergent surgical aortic valve replacement was performed successfully, with a tear at the non-left commissure closed using interrupted sutures. The patient was discharged on postoperative day 14 with no paravalvular leakage. Chronic corticosteroid use may be a risk factor for annular ruptures during TAVR. Careful balloon dilation may be necessary, especially when balloon-expandable valves are used in patients receiving long-term corticosteroids.

Impact of residual pulmonary hypertension on long-term outcomes after pulmonary endarterectomy in the modern era.

Residual pulmonary hypertension (PH) negatively impacts long-term results following pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). We sought to reveal whether modern PH therapy with PH-targeted medicine and balloon pulmonary angioplasty (BPA) improved long-term results of residual PH after PEA. Long-term findings of 80 patients who survived PEA between 2011 and 2019 were retrospectively investigated. One month after PEA, 30 patients developed residual PH defined as mean pulmonary artery pressure (mPAP) ≥25 mmHg, of whom 23 were treated by PH-targeted medicine and 9 by BPA. Patients with residual PH acquired considerably better functional status and exercise capacity after PEA, however, exhibited significantly worse survival rates than those without. Eleven patients died during follow-up: 8 patients with residual PH and 3 controls. Among patients with residual PH, the deceased had a significantly lower %decrease in mPAP from 1 month to 1 year following PEA (7.4 [-32.6 to 8.0] % vs. 10.4 [3.7-27.8] %, p = 0.03) and higher mPAP at 1 year following PEA (39.5 [33.25-42.5] vs. 27 [26-34] mmHg, p < 0.01) despite PH-targeted medicine than the survived. No patients passed away from right heart failure, and there was no difference between the groups in CTEPH-related mortality. Modern PH therapy was used to address the majority of residual PH. Long-term survival after PEA was negatively impacted by residual PH, but it appeared that long-term mortality was also correlated with unrelieved residual PH despite PH-targeted medicine. Modern PH therapy may have enhanced functional status and excercise capacity, and averted fatal right heart failure.

Late outcome of coronary artery bypass grafting with or without mitral repair for moderate or moderate-severe ischemic mitral regurgitation.

BACKGROUND: Operative indication of the additional mitral repair for moderate ischemic mitral regurgitation (MR) in the setting of coronary artery bypass grafting (CABG) is still unclear. METHODS: This study was designed as the nation-wide multi-center retrospective analysis with additional survival data. CABGs without past heart surgery registered in 2014 and 2015 were included. Concomitant surgery other than tricuspid or arrhythmia surgery, mitral replacement, and off-pump cases, was excluded. Grade 1 or 4 MR, and ejection fraction < 20 or > 50 were excluded. Additional questionnaire was sent to each hospital, regarding the pathology of MR and clinical outcomes. Additional data were registered between May 28, 2021 and Dec 31, 2021, and the primary outcomes were all-death and cardiac death. The secondary outcomes were heart failure and cerebrovascular event requiring admission, mitral re-intervention. Patients underwent on-pump CABG (CABG only group 221 cases) and CABG with mitral repair (CABG + Mitral repair group 276 cases) were enrolled. RESULTS: After Propensity score matching, 362 cases (CABG only 181cases vs CABG + mitral repair 181 cases) were matched. Cox regression model showed no statistical difference in the long-term survival between CABG alone group and combined procedure group (p = 0.52). Cardiac death (p = 1.00), heart failure (p = 0.68), and cerebrovascular event (p - 0.80) requiring admission were not different between groups as well. The incidence of mitral re-intervention was very few (2 cases in CABG only group, 4 cases in CABG + mitral repair group). CONCLUSIONS: In patients with moderate ischemic MR, additional mitral repair to CABG did not improve long-term survival, freedom from heart failure, or cerebrovascular event.

Mechanical vs Bioprosthetic Aortic Valve Replacement in Patients on Dialysis: Long-term Outcomes.

BACKGROUND: Using the Japan National Clinical Database and additional data, this study is an analysis of long-term survival of dialysis-dependent patients who underwent aortic valve replacement (AVR). METHODS: Dialysis-dependent patients who underwent de novo AVR between 2010 and 2012 and who were registered in the database were included. Concomitant aortic surgery and transcatheter aortic valve replacement were excluded. Additional data on the underlying kidney disease, the duration of dialysis, and clinical outcomes were registered between October 29, 2019, and August 30, 2020. The primary outcome was all-cause mortality. The secondary outcomes were cerebral infarction, cerebral bleeding, gastrointestinal bleeding, and prosthetic valve failure. RESULTS: After propensity score matching, 1016 cases (508 each in the bioprosthetic and mechanical valve groups) were matched. The median follow-up period was 3.29 years (interquartile range [IQR], 0.59 years, 6.25 years). The median survival time was 5.38 years (IQR, 1.20 and 9.26 years) in the mechanical valve group and 4.98 years (IQR, 1.69 and 9.62 years) in the bioprosthetic valve group. The Cox regression model showed no significant difference in long-term survival between the groups (mechanical valve: hazard ratio [HR], 0.895; 95% CI, 0.719-1.113; P = .318). The incidences of cerebral infarction and prosthetic valve failure requiring admission were similar between the groups. Cerebral bleeding (HR, 2.143; 95% CI, 1.125-4.080; P = .002) and gastrointestinal bleeding (HR, 2.071; 95% CI, 1.243-3.451; P = .0005) were more frequent in the mechanical valve group. CONCLUSIONS: Long-term survival of dialysis-dependent patients was similar regardless of whether mechanical valves or bioprosthetic valves were implanted. The incidences of cerebral and gastrointestinal bleeding were 2-fold higher in the mechanical valve group.

Impact of concomitant mitral regurgitation during transcatheter aortic valve replacement on 1-year survival outcomes.

BACKGROUND: We investigated the influence of concomitant mitral regurgitation (MR) in patients undergoing transcatheter aortic valve implantation on the 1-year outcome using Japan Transcatheter Valve Therapy (J-TVT) registry data. METHODS: The patients who underwent the transcatheter aortic valve implantation for aortic stenosis performed from August 2013 to December 2019 in Japan were included. History of previous valve surgery and dialysis patients were excluded. A total of 24,979 patients were included, and 1-year follow-up data were obtained from the registry (follow-up rate 98.5 %). Propensity-score matching, using multivariable logistic regression and 1:1 matching without replacement, was performed between the patients with grade 3-4 MR (MR 3-4 group) and those with grade 0-2 MR (MR 0-2 group). All-cause death and the composite outcome of death and/or heart failure events were compared. RESULTS: After propensity score matching, 3920 cases (1960 cases each in MR 0-2 group and MR 3-4 group) were extracted. The procedure success rate was 96.4 % in MR 0-2 and 96.0 % in MR 3-4 group (p = 0.56) and the surgical conversion rate was 0.7 % in MR 0-2 group and 0.8 % in MR 3-4 group (p = 0.58). Cox regression model showed no statistical difference in 1-year survival rate between MR 0-2 group (89.4 %) and MR 3-4 group (89.6 %) (p = 0.80). However, freedom from 1-year death and/or heart failure event was lower in MR 3-4 (86.3 %) than in MR 0-2 group (88.9 %) (p = 0.01). This trend was also found in the subgroup of New York Heart Association (NYHA) class 1-2 but not in the subgroup of NYHA class 3-4. CONCLUSIONS: One-year survival rate was not different between groups but freedom from death and/or heart failure events was lower in patients with preoperative MR grade 3-4 than in patients with preoperative MR grade 0-2 after transcatheter aortic valve replacement.

Modification of pulmonary endarterectomy to prevent neurologic adverse events.

PURPOSE: Neurologic adverse events (NAEs) are a major complication after pulmonary endarterectomy (PEA) performed under periods of deep hypothermic circulatory arrest (HCA) for chronic thromboembolic pulmonary hypertension. We modified the PEA strategy to prevent NAEs and evaluated the effectiveness of these modifications. METHODS: We reviewed the surgical outcomes of 87 patients divided into the following three groups based on the surgical strategy used: group S (n = 49), periods of deep HCA with alpha-stat strategy; group M1 (n = 19), deep HCA with modifications of slower cooling and rewarming rates and the pH-stat strategy for cooling: and group M2 (n = 13), multiple short periods of moderate HCA. RESULTS: PEA provided significant improvement of pulmonary hemodynamics in each group. Sixteen (29%) of the 49 group S patients suffered NAEs, associated with total circulatory arrest time (cutoff, 57 min) and Jamieson type I disease. The Group M1 and M2 patients did not suffer NAEs, although the group M1 patients had prolonged cardiopulmonary bypass (CPB) and more frequent respiratory failure. CONCLUSIONS: NAEs were common after PEA performed under periods of deep HCA. The modified surgical strategy could decrease the risk of NAEs but increase the risk of respiratory failure. Multiple short periods of moderate HCA may be useful for patients at risk of NAEs.

Diagnosis of Atrial Fibrillation Using Machine Learning With Wearable Devices After Cardiac Surgery: Algorithm Development Study.

BACKGROUND: Some attempts have been made to detect atrial fibrillation (AF) with a wearable device equipped with photoelectric volumetric pulse wave technology, and it is expected to be applied under real clinical conditions. OBJECTIVE: This study is the second part of a 2-phase study aimed at developing a method for immediate detection of paroxysmal AF, using a wearable device with built-in photoplethysmography (PPG). The objective of this study is to develop an algorithm to immediately diagnose AF by an Apple Watch equipped with a PPG sensor that is worn by patients undergoing cardiac surgery and to use machine learning on the pulse data output from the device. METHODS: A total of 80 patients who underwent cardiac surgery at a single institution between June 2020 and March 2021 were monitored for postoperative AF, using a telemetry-monitored electrocardiogram (ECG) and an Apple Watch. AF was diagnosed by qualified physicians from telemetry-monitored ECGs and 12-lead ECGs; a diagnostic algorithm was developed using machine learning on the pulse rate data output from the Apple Watch. RESULTS: One of the 80 patients was excluded from the analysis due to redness caused by wearing the Apple Watch. Of 79 patients, 27 (34.2%) developed AF, and 199 events of AF including brief AF were observed. Of them, 18 events of AF lasting longer than 1 hour were observed, and cross-correlation analysis showed that pulse rate measured by Apple Watch was strongly correlated (cross-correlation functions [CCF]: 0.6-0.8) with 8 events and very strongly correlated (CCF>0.8) with 3 events. The diagnostic accuracy by machine learning was 0.9416 (sensitivity 0.909 and specificity 0.838 at the point closest to the top left) for the area under the receiver operating characteristic curve. CONCLUSIONS: We were able to safely monitor pulse rate in patients who wore an Apple Watch after cardiac surgery. Although the pulse rate measured by the PPG sensor does not follow the heart rate recorded by telemetry-monitored ECGs in some parts, which may reduce the accuracy of AF diagnosis by machine learning, we have shown the possibility of clinical application of using only the pulse rate collected by the PPG sensor for the early detection of AF.

Transcatheter aortic valve implantation for severe aortic stenosis in a patient with mucopolysaccharidosis type II (Hunter syndrome) accompanied by severe airway obstruction.

Mucopolysaccharidosis type II, known as Hunter syndrome, is a rare inherited metabolic disorder with glycosaminoglycan accumulation leading to progressive multisystem involvement, such as heart, respiratory, and central nervous systems. In particular, concurrence of major heart and respiratory problems in this syndrome often causes difficulty in performing curative and invasive treatments. Transcatheter aortic valve implantation (TAVI) has been an established therapy for severe aortic stenosis (AS). In patients who cannot undergo surgical aortic valve replacement because of high risk for general anesthesia, TAVI with local anesthesia has become an alternative therapy for severe AS. We report herein a case of 50-year-old man with Hunter syndrome accompanied by severe airway obstruction who underwent TAVI with local anesthesia for severe AS. .

Mid-term functional recovery after tricuspid annuloplasty concomitant with left-sided valve surgery.

BACKGROUND: To elucidate the impact of tricuspid annuloplasty concomitant with left-sided valve surgery on the right ventricular (RV) function in patients with mild or more tricuspid regurgitation (TR). METHODS: We enrolled 136 patients with mild or more TR who underwent left-sided valve surgery. Seventy-three patients underwent left-sided valve surgery alone (group non-T) and 63 underwent concomitant tricuspid annuloplasty (group T). The echocardiographic data at the latest follow-up (mean 1019 days) were compared using multiple regression analysis to adjust cofounding factors. Propensity score was calculated and included in the analysis as a covariate. In addition, propensity score matching was used for sensitive analysis (12 pairs). RESULTS: In group non-T, there were more aortic valve surgeries, and fewer mitral valve surgeries. At baseline, body surface area, New York Heart Association class, and prevalence of atrial fibrillation were significantly different between groups. On preoperative echocardiography, left and right atrial diameter, RV diameter, and tricuspid annular diameter were larger in group T, whereas there was no significant difference in RV fractional area change. In multiple regression analyses, RV diameter in diastole was significantly lower and RV fractional area change was significantly higher at the follow-up period in group T. These results were not attenuated even in subgroup analysis in patients with only mild TR or mitral valve surgery alone. CONCLUSION: Among patients with mild or more TR, RV dimensional and functional recovery was not obtained with left-sided valve surgery alone. Adding tricuspid annuloplasty may potentially achieve both outcomes.

Computational fluid dynamic study of multiple sequential coronary artery bypass anastomoses in a native coronary stenosis model.

BACKGROUND: The objective of this study was to evaluate the hemodynamic characteristics of multiple sequential coronary artery bypass grafting using a computational fluid dynamics study. METHODS: First anastomosis was configured into parallel and diamond anastomoses, and the second anastomosis was set as end-side anastomosis. The anastomosis incision lengths were fixed at 2 mm. Various combinations of the degree of first and second stenoses were studied. The diameter of both the native and graft vessels was set at 2 mm. The inlet boundary condition was set by a sample of the transient time flow measurement, which was measured intraoperatively. RESULTS: Both swirl and stagnation were observed at the outlets of the stenosis and the anastomosis sites. When the severity of the second stenosis was larger than that of the first, the flow at the outlet of the second stenosis was more unstable. Higher wall shear stress and larger oscillatory shear index regions were observed when the severe stenosis was bypassed by the first anastomosis, especially with diamond anastomoses. Less energy loss and higher energy efficiency were present when the vessel with more severe stenosis was bypassed as the second anastomosis. Energy loss was lower and energy efficiency was higher with parallel anastomosis than diamond anastomosis when the severity of the two stenoses was the same. CONCLUSIONS: It is ideal to bypass the less severe stenosis vessel first with a parallel anastomosis method when employing multiple sequential bypass grafting. This improves hemodynamic stability and energy efficiency, according to a computational fluid dynamics model.

Pulmonary Embolectomy for Acute Pulmonary Embolism: A Word of Caution.

Pulmonary embolectomy is an effective treatment of acute pulmonary embolism (APE) but not for chronic pulmonary thromboembolism. We described surgical experience of two patients with APE in preexistent unidentified chronic pulmonary thromboembolism. One patient who presented with severe hypoxia but stable hemodynamics underwent successful pulmonary endarterectomy for proximal organized thrombus instead of pulmonary embolectomy. The other patient who required extracorporeal membrane oxygenation for severe hypoxia developed right heart failure because of residual distal organized thrombus after pulmonary embolectomy. Clinical and radiographical presentation of APE in chronic pulmonary thromboembolism mimics APE, and thus, candidates of pulmonary embolectomy should be carefully selected.

Use of a Smart Watch for Early Detection of Paroxysmal Atrial Fibrillation: Validation Study.

BACKGROUND: Wearable devices with photoplethysmography (PPG) technology can be useful for detecting paroxysmal atrial fibrillation (AF), which often goes uncaptured despite being a leading cause of stroke. OBJECTIVE: This study is the first part of a 2-phase study that aimed at developing a method for immediate detection of paroxysmal AF using PPG-integrated wearable devices. In this study, the diagnostic performance of 2 major smart watches, Apple Watch Series 3 and Fitbit (FBT) Charge HR Wireless Activity Wristband, each equipped with a PPG sensor, was compared, and the pulse rate data outputted from those devices were analyzed for precision and accuracy in reference to the heart rate data from electrocardiography (ECG) during AF. METHODS: A total of 40 subjects from patients who underwent cardiac surgery at a single center between September 2017 and March 2018 were monitored for postoperative AF using telemetric ECG and PPG devices. AF was diagnosed using a 12-lead ECG by qualified physicians. Each subject was given a pair of smart watches, Apple Watch and FBT, for simultaneous pulse rate monitoring. The heart rate of all subjects was also recorded on the telemetry system. Time series pulse rate trends and heart rate trends were created and analyzed for trend pattern similarities. Those trend data were then used to determine the accuracy of PPG-based pulse rate measurements in reference to ECG-based heart rate measurements during AF. RESULTS: Of the 20 AF events in group FBT, 6 (30%) showed a moderate or higher correlation (cross-correlation function>0.40) between pulse rate trend patterns and heart rate trend patterns. Of the 16 AF events in group Apple Watch (workout [W] mode), 12 (75%) showed a moderate or higher correlation between the 2 trend patterns. Linear regression analyses also showed a significant correlation between the pulse rates and the heart rates during AF in the subjects with Apple Watch. This correlation was not observed with FBT. The regression formula for Apple Watch W mode and FBT was X=14.203 + 0.841Y and X=58.225 + 0.228Y, respectively (where X denotes the mean of all average pulse rates during AF and Y denotes the mean of all corresponding average heart rates during AF), and the coefficient of determination (R2) was 0.685 and 0.057, respectively (P<.001 and .29, respectively). CONCLUSIONS: In this validation study, the detection precision of AF and measurement accuracy during AF were both better with Apple Watch W mode than with FBT.

A case of left ventricular assist device application for chemotherapy-related cardiomyopathy caused by trastuzumab and anthracycline.

Left ventricular assist device (LVAD) is an established therapy for patients with severe heart failure. Because the incidence of cardiotoxicity owing to anticancer agents is low, it is difficult to predict the recovery prospects when the cause of heart failure is due to anticancer agents. In this context, cancer patients who present with severe symptoms of heart failure and who fail medical therapy for heart failure may pose a dilemma, especially in countries such as Japan where implantable LVADs are not approved for purposes other than bridging to transplant. Recently, we encountered a 32-year-old woman with chemotherapy-related cardiomyopathy that developed after anticancer treatment using trastuzumab and anthracycline. LVAD therapy was the only option to save the young woman. The patient received an extracorporeal LVAD, her cardiac function gradually recovered while on support, and the device was successfully removed.

Utility of computed tomography in cases of aortic valve stenosis before and after transcatheter aortic valve implantation.

Trans-catheter aortic valve implantation (TAVI) has been recognized as a useful treatment for patients with severe aortic valve stenosis, particularly those with moderate to high risks of open heart surgery. A thorough evaluation of the aortic valve complex, including the size or presence of calcifications of the leaflets and annulus, is important for the selection of appropriate candidates, artificial valve types and approach. Echocardiography is useful for the precise evaluation of aortic valve stenosis severity and aortic valve complex morphology, but it is not useful to evaluate three-dimensional aortic valve anatomy and pathway for the catheter of aortic valve implantation. Electrocardiography (ECG)-gating computed tomography (CT) has recently been recognized as a useful modality for evaluating significant coronary artery stenosis because of its higher spatial and temporal resolution and diagnostic accuracy based on recent studies. ECG-gating CT is also useful for evaluating aortic valve complex morphology, including calcifications and whole aorta and iliac arteries, as the access route of catheter in TAVI. TAVI candidates, who are at high risk of open surgery, tend to be old and require anti-platelet after TAVI; therefore CT, is also useful for screening for non-cardiac diseases including malignant tumors just before TAVI. Therefore, here we introduce the utility of cardiac and whole body CT in cases of severe aortic valve stenosis before and after TAVI.

Computational fluid dynamic study of different incision length of coronary artery bypass grafting in a native coronary stenosis model.

BACKGROUND: The objective of this study was to evaluate hemodynamic patterns in end-side coronary artery bypass grafting with different anastomosis length by computational fluid dynamic study in the native coronary stenosis model. METHODS: The fluid dynamic computations were carried out using ANSYS CFX. Incision length was set to be 2, 4, 6, 8, 10 mm. The angle between the two blood vessels corresponded to the length of the incision. Native vessels were set to be 90% stenosis. The radius of both native and graft vessels was set to be 2 mm. The inlet boundary condition was set by the sample of the transient time flow which was measured intraoperatively. RESULTS: The energy efficiency was higher and energy loss was lower when the anastomosis length was longer until 8 mm. However, energy efficiency was lowest and energy loss was highest in the 10-mm model. In the 10-mm incision model, the streamline showed the scanty bypass flow in the bottom. Vortex showed that only 10-mm model showed the vortex just distal to the stenosis in the native inlet, and more vortex in native outlet than other length models. The oscillatory shear index (OSI) was higher in the outlet top in all models. And only 10-mm model showed high oscillatory index just distal to the stenosis. CONCLUSIONS: In the end-side anastomosis, an anastomosis length of 8 mm was the ideal length with less flow complexity, low OSI, and less energy loss and high energy efficiency in the native 90% stenosis model.

Left Ventricular Aneurysm After Post-Infarction Ventricular Septal Defect Repair.

The surgical indication and optimal approach for ischemic mitral regurgitation with ventricular septal defect remain uncertain. Very few studies have reported the occurrence of left ventricular aneurysms after repair of ischemic ventricular septal defects. We report a case of a left posterior ventricular aneurysm that developed after an urgent operation to repair an acute ischemic posterior ventricular septal defect using the double-patch sandwich technique via a right ventriculotomy.