Early achievement of walkability after cardiac surgery and the risk of cardiovascular disease after hospital discharge.

AIMS: This study aimed to investigate the association between the time to achieve walkability after cardiac surgery and the risk of cardiovascular disease after hospital discharge. METHODS: We conducted a prospective cohort study involving 553 ambulatory patients aged 71.5 (range, 64.0-77.0) years who underwent cardiac surgery. All patients were divided into five groups based on the time to achieve walkability ≥100 m within 1, 2, 3, 4 or 5 days after cardiac surgery. We examined the risk of post-cardiovascular disease outcomes, including readmission due to heart failure, ischaemic heart disease and other cardiovascular disease, according to the time to achieve walkability with reference to 5 days using the Fine and Gray regression model, considering competing risks. RESULTS: In the survival curve analysis, we examined the time to experience post-cardiovascular disease incidence after hospital discharge. During a median of 3.3 years of follow-up, 118 patients developed cardiovascular disease. We observed a positive association between the time to achieve walkability and cardiovascular disease risk, particularly heart failure. The multivariate hazard ratios (95% confidence intervals) for heart failure readmission were N/A (not assessed due to the sample size being too small) for 1 day, 0.31 (0.10-0.99) for 2 days, 0.60 (0.21-1.79) for 3 days and 0.76 (0.22-2.72) for 4 days (P for trend = 0.032). CONCLUSIONS: The shorter walkability achievement time was associated with a lower risk of cardiovascular diseases, more specifically heart failure readmission, among patients who underwent cardiac surgery. The time required to achieve walkability is a useful predictor for cardiovascular diseases after hospital discharge.

Delayed coronary artery stenosis: a rare complication of the left atrial clipping device.

A clipping device may impinge on the coronary artery following left atrial appendage occlusion during cardiac surgery, causing rare cardiac ischaemia perioperatively. This report highlights a case of delayed severe coronary artery stenosis resulting in ventricular fibrillation 2 months after cardiac surgery with the implantation of a left atrial clipping device. Following a percutaneous coronary intervention, the patient underwent clip removal surgery. Postoperative three-dimensional heart model verification revealed that the base of the left atrial appendage was more dorsal than usual, thereby increasing the potential risk of the clip impinging on the coronary artery. We should remember that this rare complication can occur after left atrial clipping, either in the early postoperative period or later.

Changes in cardiac sympathetic nerve activity on 123 I-metaiodobenzylguanidine scintigraphy after MitraClip therapy.

AIMS: In patients with heart failure, over-activation of the cardiac sympathetic nerve (CSN) function is associated with severity of heart failure and worse outcome. The effects of MitraClip therapy on the CSN activity in patients with mitral regurgitation (MR) remained unknown. In this study, we evaluated the impact of the MitraClip therapy on CSN activity assessed by 123 I-metaiodobezylguanidine (MIBG) scintigraphy. METHODS AND RESULTS: We enrolled consecutive patients with moderate-to-severe (3+) or severe (4+) MR who were scheduled to undergo MitraClip procedure in this prospective observational study. MIBG scintigraphy was performed at baseline and 6 months after the MitraClip procedure to evaluate the heart-mediastinum ratio and washout rate (WR). Changes in these MIBG parameters were analysed. Of the 13 consecutive patients, 10 were successfully treated with MitraClip procedure and completed follow-up assessment. With regard to the MIBG parameters, changes in the early and delayed heart-mediastinum ratio from baseline to 6 months were not significant (2.16 ± 0.42 to 2.06 ± 0.34, P = 0.38 and 1.87 ± 0.39 to 1.83 ± 0.39, P = 0.43, respectively), whereas WR was significantly decreased (38.6 ± 3.9% to 32.6 ± 3.94%, P = 0.002). CONCLUSIONS: The CSN activity of the WR on MIBG imaging was improved 6 months after MitraClip therapy in patients with 3+ or 4+ MR.

Insights into the passive mechanical behavior of left ventricular myocardium using a robust constitutive model based on full 3D kinematics.

Myocardium possesses a hierarchical structure that results in complex three-dimensional (3D) mechanical behavior, forming a critical component of ventricular function in health and disease. A wide range of constitutive model forms have been proposed for myocardium since the first planar biaxial studies were performed by Demer and Yin (J. Physiol. 339 (1), 1983). While there have been extensive studies since, none have been based on full 3D kinematic data, nor have they utilized optimal experimental design to estimate constitutive parameters, which may limit their predictive capability. Herein we have applied our novel 3D numerical-experimental methodology (Avazmohammadi et al., Biomechanics Model. Mechanobiol. 2018) to explore the applicability of an orthotropic constitutive model for passive ventricular myocardium (Holzapfel and Ogden, Philos. Trans. R. Soc. Lond.: Math. Phys. Eng. Sci. 367, 2009) by integrating 3D optimal loading paths, spatially varying material structure, and inverse modeling techniques. Our findings indicated that the initial model form was not successful in reproducing all optimal loading paths, due to previously unreported coupling behaviors via shearing of myofibers and extracellular collagen fibers in the myocardium. This observation necessitated extension of the constitutive model by adding two additional terms based on the I8(C) pseudo-invariant in the fiber-normal and sheet-normal directions. The modified model accurately reproduced all optimal loading paths and exhibited improved predictive capabilities. These unique results suggest that more complete constitutive models are required to fully capture the full 3D biomechanical response of left ventricular myocardium. The present approach is thus crucial for improved understanding and performance in cardiac modeling in healthy, diseased, and treatment scenarios.

Postoperative atrial fibrillation is associated with delayed early rehabilitation after heart valve surgery: a multicenter study.

OBJECTIVE: Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery. The aim of this multicenter study was to determine the relationship between POAF and patients' progress in early rehabilitation after heart valve surgery. METHODS: We enrolled 302 patients (mean age, 69±10 years) who had undergone heart valve surgery. POAF was monitored using continuous electrocardiogram telemetry, and the Short Physical Performance Battery (SPPB) was used to assess lower-extremity function before surgery and at the time of discharge. Progress in early rehabilitation was evaluated by the duration from the surgery to independent walking. We determined factors associated delayed early rehabilitation and evaluated the interplay of POAF and delayed early rehabilitation in increasing the risk of decline in lower-extremity function from preoperatively to hospital discharge. RESULTS: Multivariate analysis determined POAF to be independent predictors of delayed early rehabilitation after heart valve surgery (OR: 3.906, P = .01). The association between delayed early rehabilitation and decline in lower extremity function was stronger in patients with POAF (OR: 2.73, P = .041) than in those without (OR: 2.22, P = .052). CONCLUSIONS: POAF was clinical predictors of delayed early rehabilitation in patients undergoing heart valve surgery. The combination of POAF with delayed early rehabilitation conferred a high risk of decline in lower-extremity function during hospitalization.

Factors related to physical functioning decline after cardiac surgery in older patients: A multicenter retrospective study.

BACKGROUND: As few studies have examined physical functioning changes after cardiac surgery, the factors related to the decline in physical functioning remain unclear. This study aimed to investigate the factors related to physical functioning decline after cardiac surgery in older patients. METHODS: The final study sample consisted of 523 older (≥65 years) patients (age 74.2±6.1 years, 66% male) who underwent cardiac surgery at 8 Japanese institutions. We excluded patients who were unable to walk independently or had a slow gait speed (<0.8m/s) before surgery, and those who were unable to regain independent walking after surgery. We divided the patients into two groups, a decline-in-gait-speed group and a non-decline-in-gait-speed group, according to whether their gait speed was less than 0.8m/s at discharge. We analyzed patients' clinical characteristics to identify the factors that predicted the postoperative decline in gait speed. RESULTS: Eighty-nine patients (17.0%) showed a postoperative decline in gait speed. Multivariate logistic regression analysis showed that the following factors predicted a postoperative decline in gait speed: age [odds ratio (OR) 1.06, 95% confidence interval (CI) 1.02-1.11]; estimated glomerular filtration rate (OR 0.98, CI 0.96-0.99); preoperative gait speed (OR 0.01, CI 0.00-0.08); and the postoperative day on which the patient could walk independently (OR 1.08, CI 1.02-1.14). CONCLUSIONS: Physical functioning declined in 17% of patients after surgery. The decline could be predicted by several clinical factors, including some that are modifiable. These results suggest that further interventional research on rehabilitation before and after cardiac surgery for older patients might help overcome the decline in physical functioning.

Impact of preoperative frailty on regaining walking ability in patients after cardiac surgery: Multicenter cohort study in Japan.

BACKGROUND: This study aimed to examine the relationship between preoperative frailty and the reacquisition of walking ability in patients after cardiac surgery. METHODS: 450 patients who underwent cardiac surgery were included as subjects. We implemented the Short Physical Performance Battery (SPPB) before surgery and classified subjects into three groups according to the SPPB score: SPPB 10-12, SPPB 7-9, and SPPB 0-6. We examined the postoperative day and the rate of the reacquisition of walking ability after surgery, and compared them among three groups. In addition, we calculated the cutoff value for the SPPB score to regain walking ability by performing a receiver operating characteristic curve analysis. RESULTS: The postoperative day of the reacquisition of walking ability in SPPB 10-12 was earlier than other groups (SPPB 10-12: 4.0 days, SPPB 7-9: 4.5 days, SPPB 0-6: 6.0 days, p < 0.01), and SPPB 0-6 was lower than other groups in the rate of the reacquisition of walking ability (SPPB 10-12: 98.8%, SPPB 7-9: 96.4%, SPPB 0-6: 76.2%, p < 0.01). The cutoff value for SPPB was ≧9(Area under the curve: 0.85, sensitivity: 0.82, specificity: 0.71, p < 0.001). CONCLUSION: Preoperative frailty affected the day of the reacquisition of walking ability in patients after cardiac surgery. The preoperative SPPB cutoff value which indicates the feasibility of reacquisition walking ability after surgery was ≧ 9.

Clampless aortic punch system for making a large-diameter access route without side-biting clamp: a preliminary study.

Although thoracic endovascular aneurysm repair (TEVAR) has been getting popularity as a less-invasive procedure, the treatment of thoracic aortic aneurysm with atherosclerotic aortic disease is still challenging. In hybrid TEVAR through the median sternotomy approach, side-biting clamp of the ascending aorta is often necessary for making an access route; however, it could cause embolic complication and aortic dissection. This study aimed to present the results of our preliminary study on the clampless aortic punch system (APS). The swine aorta was used as experimental specimen (diameter 16-20 mm). A 10-mm collagen-impregnated knitted Dacron graft was anastomosed to the aorta, and the APS was inserted into it. After piercing the aorta with the inner fish hook of the APS, the aortic wall was scooped out by an outer round cutter. Three different-angled cutters (0°, 15°, and 30°) were tested three times. The diameter of the punched-out lesion ranged from 6 to 9 mm (median 8 mm). Macroscopically, no major vessel injuries were seen 15° series, whereas minor or major vessel injuries were seen 30° and 0° series, respectively. Histological findings of 15° series confirmed the sharp edge of the stump and abrupt interruption of the elastic fiber without destruction of the normal three-layer structure of the aortic wall. This study suggests that our clampless APS could reduce the risk of stroke and aortic injury in hybrid TEVAR, and an animal study confirming its utility is now under consideration.

Mitral annuloplasty ring suture forces: Impact of surgeon, ring, and use conditions.

OBJECTIVE: The study objective was to quantify the effect of ring type, ring-annulus sizing, suture position, and surgeon on the forces required to tie down and constrain a mitral annuloplasty ring to a beating heart. METHODS: Physio (Edwards Lifesciences, Irvine, Calif) or Profile 3D (Medtronic, Dublin, Ireland) annuloplasty rings were instrumented with suture force transducers and implanted in ovine subjects (N = 23). Tie-down forces and cyclic contractile forces were recorded and analyzed at 10 suture positions and at 3 levels of increasing peak left ventricular pressure. RESULTS: Across all conditions, tie-down force was 2.7 ± 1.4 N and cyclic contractile force was 2.0 ± 1.2 N. Tie-down force was not meaningfully affected by any factor except surgeon. Significant differences in overall and individual tie-down forces were observed between the 2 primary implanting surgeons. No other factors were observed to significantly affect tie-down force. Contractile suture forces were significantly reduced by ring-annulus true sizing. This was driven almost exclusively by Physio cases and by reduction along the anterior aspect, where dehiscence is less common clinically. Contractile suture forces did not differ significantly between ring types. However, when undersizing, Profile 3D forces were significantly more uniform around the annular circumference. A suture's tie-down force did not correlate to its eventual contractile force. CONCLUSIONS: Mitral annuloplasty suture loading is influenced by ring type, ring-annulus sizing, suture position, and surgeon, suggesting that reports of dehiscence may not be merely a series of isolated errors. When compared with forces known to cause suture dehiscence, these in vivo suture loading data aid in establishing potential targets for reducing the occurrence of ring dehiscence.

Injectable Shear-Thinning Hydrogels for Minimally Invasive Delivery to Infarcted Myocardium to Limit Left Ventricular Remodeling.

BACKGROUND: Injectable, acellular biomaterials hold promise to limit left ventricular remodeling and heart failure precipitated by infarction through bulking or stiffening the infarct region. A material with tunable properties (eg, mechanics, degradation) that can be delivered percutaneously has not yet been demonstrated. Catheter-deliverable soft hydrogels with in vivo stiffening to enhance therapeutic efficacy achieve these requirements. METHODS AND RESULTS: We developed a hyaluronic acid hydrogel that uses a tandem crosslinking approach, where the first crosslinking (guest-host) enabled injection and localized retention of a soft (<1 kPa) hydrogel. A second crosslinking reaction (dual-crosslinking) stiffened the hydrogel (41.4±4.3 kPa) after injection. Posterolateral infarcts were investigated in an ovine model (n≥6 per group), with injection of saline (myocardial infarction control), guest-host hydrogels, or dual-crosslinking hydrogels. Computational (day 1), histological (1 day, 8 weeks), morphological, and functional (0, 2, and 8 weeks) outcomes were evaluated. Finite-element modeling projected myofiber stress reduction (>50%; P<0.001) with dual-crosslinking but not guest-host injection. Remodeling, assessed by infarct thickness and left ventricular volume, was mitigated by hydrogel treatment. Ejection fraction was improved, relative to myocardial infarction at 8 weeks, with dual-crosslinking (37% improvement; P=0.014) and guest-host (15% improvement; P=0.058) treatments. Percutaneous delivery via endocardial injection was investigated with fluoroscopic and echocardiographic guidance, with delivery visualized by magnetic resonance imaging. CONCLUSIONS: A percutaneous delivered hydrogel system was developed, and hydrogels with increased stiffness were found to be most effective in ameliorating left ventricular remodeling and preserving function. Ultimately, engineered systems such as these have the potential to provide effective clinical options to limit remodeling in patients after infarction.

Medium-term neurological complications after off-pump coronary artery bypass grafting with and without aortic manipulation.

BACKGROUND: This study aimed to assess the impact of aortic manipulation during off-pump coronary artery bypass (OPCAB) on neurological complications. METHODS AND RESULTS: Of 336 isolated OPCAB surgeries, the aorta was untouched in 264 cases (group A), whereas it was manipulated by a side-biting clamp in 72 (group B). The average follow-up was 2.9±2.5 years. One patient in each group developed postoperative stroke (P=0.38). The prevalence of triple-vessel disease (group A 40.9% vs. group B 61.1%; P=0.0003) and left main trunk disease (group A 30.7% vs. group B 47.2%; P=0.1) was lower in group A than in group B. The number of bypass grafts (group A 2.18±0.97 vs. group B 3.00±0.97; P=0.0001) was lower in group A than in group B. The prevalence of preoperative atrial fibrillation and the incidence of new-onset postoperative atrial fibrillation were not different between groups (P=0.74 and 0.86, respectively). Survival rate and freedom from major adverse cardiac events were not different between groups (P=0.87 and 0.51, respectively). However, freedom from neurological complications was significantly lower in group A (P=0.0006). The Cox hazard model showed that aortic manipulation (P=0.004; odds ratio, 6.18; 95% confidence interval, 1.8-21.6) and preoperative atrial fibrillation (P=0.001; odds ratio, 14.0; 95% confidence interval, 2.7-72.5) were risk factors for neurological complications. CONCLUSION: Although there was no difference in the incidence of immediate postoperative neurological complications, there were fewer medium-term neurological complications in OPCAB cases without aortic manipulation.

Preoperative high N-terminal pro-B-type natriuretic peptide level can predict the incidence of postoperative atrial fibrillation following off-pump coronary artery bypass grafting.

OBJECTIVE: N-terminal pro-B type natriuretic peptide (NT-pro-BNP) is one of the biomarkers, increased by myocardial ischemia or subsequent, burdened wall stress. The aim of this study was to assess if NT-pro-BNP can predict the incidence of atrial fibrillation (AF) after off-pump coronary artery bypass grafting (OPCAB). METHODS: NT-pro-BNP was measured preoperatively in 100 OPCAB patients without preoperative AF. Patients were divided into the AF group (n = 36) of those who developed postoperative AF, and the sinus rhythm (SR) group (n = 64), of those who did not. Odds ratio analysis was carried out with a logistic regression model using the threshold of the high quartile. RESULTS: Age was more advanced in group AF (70.8±8.7 years old) than in group SR(66.7±8.5 years old), P = 0.025. There were more emergencies in group AF (22.2%) than in group SR (10.9%), P = 0.15. Preoperative NT-pro-BNP was significantly higher in group AF (509.6±641.6 pg/mL) than in group SR (241.1±302.7 pg/mL), P = 0.006. Preoperative administration of statins was relatively greater in group SR (73.4%) than in group AF (58.3%), P = 0.18. Four factors withaPvalue below 0.2 in the univariate analysis were extracted, which were preoperative administration of statins, emergency, high NT-pro-BNP (>348 pg/mL, high quartile), and advanced age (>75 years old, high quartile). The constructed logistic regression model revealed that high NT-pro-BNP(>348 pg/mL, high quartile) was the only predictor of postoperative AF after OPCAB(P = 0.05; OR, 2.60; 95% CI, 0.96-7.05). CONCLUSIONS: A high preoperative level of NT-pro-BNP could predict the incidence of postoperative AF after OPCAB.

[Reoperation of Blalock-Taussig shunt for double outlet right ventricle and pulmonary atresia in an adult].

A 36-year-old man was admitted to our hospital due to dyspnea and pneumonia. He had undergone left classical Blalock-Taussig shunt at 5 years old and right modified Blalock-Taussig shunt at 16 years old, because he was judged as no indication for any radical operation. Since the last surgery, he had stopped visiting hospital. Computed tomography showed pneumonia and pulmonary embolism in the left lower lung and occlusion of the right modified Blalock-Taussig shunt. After pneumonia was improved by antibiotic treatment, he underwent reoperation of the right modified Blalock-Taussig shunt using 8 mm knitted Dacron graft. Postoperative course was uneventful and dyspnea and cyanosys were improved. We successfully treated a complicated case of an adult congenital heart disease by reoperation of the right modified Blalock-Taussig shunt.

Impact of preexisting cerebral ischemia detected by magnetic resonance imaging and angiography on late outcome after coronary artery bypass surgery.

BACKGROUND: The aim of this study was to assess the impact of preexisting ischemia detected by brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) on long-term survival, and cardiac and neurologic events after coronary artery bypass grafting (CABG). METHODS: Of 923 patients who underwent CABG between 1994 and 2007, 887 patients (96.1%) were followed up. Preoperative brain MRI and MRA were performed in 619 patients. Ischemia was detected by brain MRI and MRA in 158 patients (group A), but not in 461 patients (group B). Preoperative characteristics, follow-up survival, and cardiac and neurological events were investigated. RESULTS: The average follow-up period was 6.0 ± 4.3 years. Univariate analysis showed that patients in group A (68.5 ± 6.5 years) were older than those in group B (64.5 ± 8.6 years) (p = 0.0001). Preoperative left ventricular ejection fraction was less in group A (0.516 ± 0.175) than in group B (0.556 ± 0.165) (p = 0.02). The prevalence of peripheral vascular disease was higher in group A (14 patients: 8.9%) than in group B (11 patients: 2.4%) (p = 0.001). The rate of on-pump CABG was lower in group A (115 patients; 72.8%) than in group B (383 patients; 83.1%) (p = 0.007). Survival rate was significantly lower (p = 0.062), and freedom from major adverse cardiac event or stroke were significantly lower in group A (p = 0.0002, and p = 0.0001, respectively; log-rank test). However, the Cox proportional hazard model showed that preoperative brain ischemia detected by brain MRI and MRA affected only freedom from neurologic events (p = 0.02; hazard ratio 2.52; 95% confidence interval 1.13 to 5.62), but not survival (p = 0.67) or major adverse cardiac event (p = 0.09). CONCLUSIONS: Preexisting ischemic findings on brain MRI and MRA in patients who underwent CABG were related only to long-term freedom from stroke, but were not related to survival or major adverse cardiac event.

Open door approach by partial sternotomy and sterno-costo-chondroplasty for annuloaortic ectasia with pectus excavatum.

A 32-year-old female patient with Marfan syndrome was admitted for repair of annuloaortic ectasia and severe pectus excavatum. Because the chest cage deformity was severe, concomitant reparative surgery of the chest wall was performed. Partial median sternotomy and left second-fifth rib division was made to obtain good surgical field. The patient underwent valve-sparing aortic root remodeling successfully. After complete neutralization of heparin, additional division of the right ribs was performed and each rib and the sternum was reshaped. Pectus excavatum was completely repaired by this method. We believe this approach is efficacious for intracardiac repair with severe pectus excavatum.

Early and long-term outcome of total arch replacement using selective cerebral perfusion.

BACKGROUND: The aim of this study was to analyze mortality and morbidity of patients undergoing total arch replacement. METHODS: We analyzed data from 122 patients who underwent total arch replacement. Total arch replacement was performed using selective cerebral perfusion, with an open distal anastomosis using a trifurcated coated graft. Univariate and multivariate analysis were performed concerning postoperative neurologic dysfunction and early mortality. Long-term mortality was estimated by the Kaplan-Meier method. RESULTS: Permanent and temporary neurologic dysfunction were 4.1% (5 cases) and 5.7% (7 cases), respectively. Hospital mortality was 8.2% (10 cases). There was no significant difference in hospital mortality or neurologic dysfunction between the two groups divided by age less than or greater than 70 years old, emergency versus elective surgery, and dissection versus true aneurysm. After multivariate analysis, independent predictors for hospital mortality were found to be infection, operation time longer than 10 hours, and EuroSCORE greater than 15; whereas those for neurologic dysfunction were operation time longer than 10 hours and ischemic heart disease. Overall long-term survival was 80.4% at 5 years and 58.9% at 10 years. CONCLUSIONS: The early and long-term outcomes of total arch replacement using selective cerebral perfusion and appropriate establishment of cardiopulmonary bypass were satisfactory.

Two types of intramolecular homolytic substitution reactions at group XIV atoms: unusual radical 1,4-Sn shifts from Si to C and carbonylative SHi reaction at Si.

4-[(Trimethylstannyl)diphenylsilyl]butanoyl radical, arising from the corresponding 3-(stannylsilyl)propyl radical and CO, undergoes an SHi reaction at Si with extrusion of trimethyltin radical to give silacyclopentanone. The parent 3-(stannylsilyl)propyl radical was also found to isomerize to (3-stannylpropyl)silyl radical via a 1,4-Sn shift from Si to C with a rate constant of 9.3 x 10(4) s-1 at 80 degrees C. Ab initio and DFT MO calculations support a front-side attack mechanism.