Acute Dapagliflozin Administration Ameliorates Cardiac Surgery-Associated Acute Kidney Injury in a Rabbit Model

BACKGROUND

 Several studies have shown that sodium-glucose cotransporter-2 inhibitors have a renoprotective effect on acute kidney injury (AKI), but their effect on cardiac surgery-associated AKI is unknown.Methods and Results:  AKI was induced in 25 rabbits without diabetes mellitus by cardiopulmonary bypass (CPB) for 2 h and they were divided into 5 groups: sham; dapagliflozin-treated sham; CPB; dapagliflozin-treated CPB; and furosemide-treated CPB (n=5 in each group). Dapagliflozin was administered via the femoral vein before initiating CPB. Kidney tissue and urine and blood samples were collected after the surgical procedure. There were no differences in the hemodynamic variables of each group. Dapagliflozin reduced serum creatinine and blood urea nitrogen concentrations, and increased overall urine output (all P<0.05). Hematoxylin and eosin staining showed that the tubular injury score was improved after dapagliflozin administration (P<0.01). Dapagliflozin administration mitigated reactive oxygen species and kidney injury molecule-1 as assessed by immunohistochemistry (both P<0.0001). Protein expression analysis showed improvement of inflammatory cytokines and apoptosis, and antioxidant enzyme expression was elevated (all P<0.05) through activation of the nuclear factor erythroid 2-related factor 2 pathway (P<0.01) by dapagliflozin.

CONCLUSIONS

 Acute intravenous administration of dapagliflozin protects against CPB-induced AKI. Dapagliflozin may have direct renoprotective effects in renal tubular cells.

Outcomes of Veno-Arterial Extracorporeal Membrane Oxygenation With Percutaneous Left Ventricular Unloading in Fulminant Myocarditis

Fulminant myocarditis requiring peripheral veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has a high mortality rate. We investigated clinical outcomes of combined use of VA-ECMO and percutaneous left ventricular assist device (VAD) (Impella) for fulminant myocarditis in 104 consecutive patients enrolled in the Japan Registry for Percutaneous VAD (J-pVAD) between October 2017 and January 2020. Patients were followed until hospital discharge and predictors of survival were analyzed with a Cox proportional hazards model. The median support duration of combined use of VA-ECMO and Impella (ECMO/Impella) was 6 days, and the median left ventricular ejection fraction improved from 15% to 52% during support ( p < 0.0001). Overall, 66 patients (63%) survived to discharge. Multivariate analysis revealed ECMO/Impella support at a transplant center as an independent predictor of survival ( p = 0.0231). Patients treated at transplant centers had better 60 days survival rates when compared to nontransplant centers (83% vs. 55%, p = 0.005). However, baseline characteristics and treatment strategies differed between the two groups. This real-world national registry database suggested the difference in survival after ECMO/Impella support for fulminant myocarditis between transplant and nontransplant centers, which may indicate hospital variations regarding patient management, although further controlled studies are needed.

Use of endoscopic hand-suturing to treat refractory bleeding from a gastric ulcer in a patient with a left ventricular assist device

We herein describe a 49-year-old man with severe heart failure due to fulminant myocarditis who underwent left ventricular assist device implantation and received clopidogrel and warfarin as antithrombotic agents. The patient developed anemia secondary to chronic bleeding gastric hyperplastic polyps, necessitating endoscopic mucosal resection. Despite attempts to manage post-endoscopic mucosal resection bleeding from a gastric ulcer by endoscopic hemostasis using hemostatic forceps, local hemostatic agents, and polyglycolic acid sheets, the bleeding persisted. Hemostasis of the refractory bleeding was finally achieved by endoscopic hand-suturing of the ulcer. One month later, the ulcer was almost completely scarred. This case has important clinical value in that it demonstrates the efficacy of endoscopic hand-suturing even in challenging cases such as refractory bleeding gastric ulcers in patients with left ventricular assist devices.

Cannula to Femoral Artery Diameter Ratio Predicts Potential Lower-Limb Ischemia in Minimally Invasive Cardiac Surgery With Femoral Cannulation

OBJECTIVE

Lower-limb ischemia is a complication of minimally invasive cardiac surgery with femoral cannulation. Herein, we verified our strategy using distal perfusion cannulation (DPC) against this complication.

METHODS

We retrospectively assessed 91 cases of aortic valve replacement with femoral cannulation between January 2019 and March 2023. DPC was applied when lower-limb tissue oxygenation index declined by ≥20%. The cannula to femoral artery diameter ratio (C/FA) was calculated by dividing the cannula size (Fr) divided by 3 by the femoral artery inner diameter (mm). Postoperative maximum creatinine kinase (CKmax), lactate dehydrogenase (LDHmax), and lactate levels were analyzed, and univariable logistic regression and receiver operating characteristic curve analyses were employed to determine DPC predictors and the cutoff C/FA for DPC, respectively. Patients without DPC were divided into 2 subgroups based on the cutoff C/FA for further comparisons.

RESULTS

DPC was required in 9 patients. Symptomatic ischemia was not observed. All laboratory data were similar in the DPC and non-DPC groups. C/FA was significantly associated with DPC (odds ratio = 1.27, 95% confidence interval: 1.09 to 1.47, P = 0.002), and the cutoff C/FA was 0.70 (sensitivity = 0.89, specificity = 0.80). In the non-DPC group, CKmax (P = 0.027) and LDHmax (P = 0.041) were significantly higher in patients with C/FA ≥0.7 (n = 16) than in those with C/FA <0.7 (n = 66).

CONCLUSIONS

Our strategy for preventing symptomatic ischemia is reasonable and could be almost achieved without DPC when C/FA is <0.7. C/FA also predicts asymptomatic potential ischemia, and proactive DPC is preferable when C/FA is ≥0.7.

Open Versus Zone 0/1 Endovascular Aortic Repair for Arch Aneurysm: A Propensity Score-Matched Study from the National Clinical Database in Japan

BACKGROUND

Although open surgical repair (OSR) is the gold standard for treating arch aneurysms, thoracic endovascular aortic repair (TEVAR) may be a less invasive alternative. However, it remains unclear which of the 2 methods yields better outcomes. In this study, we compared the perioperative outcomes of both procedures for arch aneurysms using a nationwide surgical database.

METHODS

Data of patients who underwent elective aortic repair for true arch aneurysms were extracted from the National Clinical Database of Japan. Patients who underwent OSR and Zone 0/1 TEVAR were matched in a 1:1 ratio using propensity scores and their mortality and morbidity rates were compared.

RESULTS

A total of 2,815 and 1,125 patients underwent OSR and Zone 0/1 TEVAR, respectively. After propensity score matching, 1,058 patients were included in both groups. Compared with OSR, Zone 0/1 TEVAR was associated with a significantly higher incidence of stroke (5.8 vs. 10.0%, P < 0.001) and paraplegia/paraparesis (1.6 vs. 4.4%, P < 0.001). However, there were no significant differences in the 30-day and operative mortality rates between the 2 groups (2.2 vs. 2.7% and 4.5 vs. 5.4%, respectively). In the Zone 0/1 TEVAR group, postoperative computed tomography was performed in 92.4% of patients, and types I and III endoleaks were identified in 6.4% and 1.1% of patients, respectively.

CONCLUSIONS

Zone 0/1 TEVAR has higher incidences of stroke and paraplegia/paraparesis than OSR, with a risk of postoperative endoleaks. Resolving these problems is the key for expanding the application of Zone 0/1 TEVAR and in the meantime OSR remains the gold standard for surgically fit patients.

Prevalence of bleeding events in real-world Japanese registry for Percutaneous Ventricular Assist Device

PURPOSE

Bleeding complication is a critical risk factor for outcomes of acute heart failure patients requiring mechanical circulatory support (MCS), including percutaneous catheter-type heart pumps (Impella). The Japanese registry for Percutaneous Ventricular Assist Device (J-PVAD) is an ongoing, large-scale, real-world registry to characterize Japanese patients requiring Impella. Here we analyzed bleeding complication profiles in patients who received Impella.

METHODS

All consecutive Japanese patients who received Impella from October 2017 to January 2020 were enrolled. The 30-day survival and bleeding complications were analyzed.

RESULTS

A total of 1344 patients were included: 653 patients received Impella alone, 685 patients received a combination of veno-arterial extracorporeal membrane oxygenation and Impella (ECPELLA), and 6 patients had failed Impella delivery. Overall 30-day survival was 67.0%, with Impella alone at 81.9% and ECPELLA at 52.7%. Overall bleeding/hematoma adverse events with a relation or not-excluded relation to Impella was 6.92%. Among them, the rates of hematoma and bleeding from medical device access sites were 1.41% and 4.09%, respectively. There was no difference between etiologies for these events.

CONCLUSION

This study represents the first 3-year survival and the safety profile focused on bleeding adverse events from the J-PVAD registry. The results show that the real-world frequency of bleeding adverse events for patients who received Impella was an expected range from previous reports, and future real-world studies should aim to expand this data set to improve outcomes and adverse events.

Efficacy of Sac Coil Embolization in Endovascular Aortic Repair for Sac Shrinkage in Patients at a High Risk of Type II Endoleak from Lumbar Arteries

BACKGROUND

In endovascular aortic repair (EVAR), preemptive embolization of sac branch vessels is effective in preventing postoperative type II endoleak (T2EL). However, this technique has not been widely adopted especially for lumbar arteries (LAs) because of technical difficulties and time constraints. This study aimed to investigate the efficacy of nonselective sac coil embolization, which is a simpler surgical method, in postoperative sac shrinkage for patients at a high risk of T2EL from LAs.

METHODS

We retrospectively assessed 76 patients who underwent elective EVAR for abdominal aortic aneurysm with 4 or more patent LAs or at least 1 patent LA of ≥2 mm at our hospital between January 2014 and December 2022. The patients who underwent sac coil embolization were included in Group Ⅰ (n = 20), and the others were divided into 2 groups: those with an inferior mesenteric artery that was originally occluded or embolized by coils or stent graft bodies (Group Ⅱ, n = 21), and those without that (Group Ⅲ, n = 35). In Group Ⅰ, 0.035-inch coils were inserted into the sac after complete stent graft deployment. The cumulative incidence of sac shrinkage (≥5 mm) was compared between the groups. Further, univariable and multivariable Cox regression analyses were used to determine the predictors of sac shrinkage.

RESULTS

Sac shrinkage (≥5 mm) was observed more frequently in Group Ⅰ (50%) than in Group Ⅱ (19%) and Group Ⅲ (17%) (P = 0.052 and 0.043, respectively). The cumulative incidence of sac shrinkage was significantly higher in Group Ⅰ than in Group Ⅱ (log-rank P = 0.039) and Group Ⅲ (log-rank P = 0.024). Multivariable Cox regression analyses revealed that sac embolization was a significant predictor of sac shrinkage (hazard ratio, 4.23; 95% confidence interval, 1.66-10.8; P = 0.003).

CONCLUSIONS

Nonselective sac coil embolization in EVAR is potentially effective for sac shrinkage in the early postoperative phase in patients at high risk of T2EL from LAs. This simple procedure may improve prognosis after EVAR.

Hypoxia stabilizes the H2 O2 -producing oxidase Nox4 in cardiomyocytes via suppressing autophagy-related lysosomal degradation

The hydrogen peroxide (H2 O2 )-producing NADPH oxidase Nox4, forming a heterodimer with p22phox , is expressed in a variety of cells including those in the heart to mediate adaptive responses to cellular stresses such as hypoxia. Since Nox4 is constitutively active, H2 O2 production is controlled by its protein abundance. Hypoxia-induced Nox4 expression is observed in various types of cells and generally thought to be regulated at the transcriptional level. Here we show that hypoxia upregulates the Nox4 protein level and Nox4-catalyzed H2 O2 production without increasing the Nox4 mRNA in rat H9c2 cardiomyocytes. In these cells, the Nox4 protein is stabilized under hypoxic conditions in a manner dependent on the presence of p22phox . Cell treatment with the proteasome inhibitor MG132 results in a marked decrease of the Nox4 protein under both normoxic and hypoxic conditions, indicating that the proteasome pathway does not play a major role in Nox4 degradation. The decrease is partially restored by the autophagy inhibitor 3-methyladenine. Furthermore, the Nox4 protein level is upregulated by the lysosome inhibitors bafilomycin A1 and chloroquine. Thus, in cardiomyocytes, Nox4 appears to be degraded via an autophagy-related pathway, and its suppression by hypoxia likely stabilizes Nox4, leading to upregulation of Nox4-catalyzed H2 O2 production.

Safety and Performance of the Micra VR Leadless Pacemaker in a Japanese Cohort - Comparison With Global Studies

BACKGROUND

The Micra leadless pacemaker has demonstrated favorable outcomes in global trials, but its real-world performance and safety in a Japan-specific population is unknown.Methods and Results: Micra Acute Performance (MAP) Japan enrolled 300 patients undergoing Micra VR leadless pacemaker implantation in 15 centers. The primary endpoint was the acute (30-day) major complication rate. The 30-day and 6-month major complication rates were compared to global Micra studies. All patients underwent successful implantation with an average follow-up of 7.23±2.83 months. Compared with previous Micra studies, Japanese patients were older, smaller, more frequently female, and had a higher pericardial effusion risk score. 11 acute major complications were reported in 10 patients for an acute complication rate of 3.33% (95% confidence interval: 1.61-6.04%), which was in line with global Micra trials. Pericardial effusion occurred in 4 patients (1.33%; 3 major, 1 minor). No procedure or device-related deaths occurred. Frailty significantly improved from baseline to follow-up as assessed by Japan Cardiovascular Health Study criteria.

CONCLUSIONS

In a Japanese cohort, implantation of the Micra leadless pacemaker had a high success rate and low major complication rate. Despite the Japan cohort being older, smaller, and at higher risk, the safety and performance was in line with global Micra trials.

Necrostatin-1 Attenuates Delayed Paraplegia after Transient Spinal Cord Ischemia in Rabbits by Inhibiting the Upregulation of Receptor-Interacting Protein Kinase 1 and 3

BACKGROUND

Delayed-onset paraplegia is a disastrous complication after thoracoabdominal aortic open surgery and thoracic endovascular aortic repair. Studies have revealed that transient spinal cord ischemia caused by temporary occlusion of the aorta induces delayed motor neuron death owing to apoptosis and necroptosis. Recently, necrostatin-1 (Nec-1), a necroptosis inhibitor, has been reported to reduce cerebral and myocardial infarction in rats or pigs. In this study, we investigated the efficacy of Nec-1 in delayed paraplegia after transient spinal cord ischemia in rabbits and assessed the expression of necroptosis- and apoptosis-related proteins in motor neurons.

METHODS

This study used rabbit transient spinal cord ischemia models using a balloon catheter. They were divided into a vehicle-treated group (n = 24), Nec-1-treated group (n = 24), and sham-controls (n = 6). In the Nec-1-treated group, 1 mg/kg of Nec-1 was intravascularly administered immediately before ischemia induction. Neurological function was assessed using the modified Tarlov score, and the spinal cord was removed 8 hr and 1, 2, and 7 days after reperfusion. Morphological changes were examined using hematoxylin and eosin staining. The expression levels of necroptosis-related proteins (receptor-interacting protein kinase [RIP] 1 and 3) and apoptosis-related proteins (Bax and caspase-8) were assessed using western blotting and histochemical analysis. We also performed double-fluorescence immunohistochemical studies of RIP1, RIP3, Bax, and caspase-8.

RESULTS

Neurological function significantly improved in the Nec-1-treated group compared with that in the vehicle-treated group 7 days after reperfusion (median 3 and 0, P = 0.025). Motor neurons observed 7 days after reperfusion were significantly decreased in both groups compared with the sham group (vehicle-treated, P < 0.001; Nec-1-treated, P < 0.001). However, significantly more motor neurons survived in the Nec-1-treated group than in the vehicle-treated group (P < 0.001). Western blot analysis revealed RIP1, RIP3, Bax, and caspase-8 upregulation 8 hr after reperfusion in the vehicle-treated group (RIP1, P = 0.001; RIP3, P = 0.045; Bax, P = 0.042; caspase-8, P = 0.047). In the Nec-1-treated group, the upregulation of RIP1 and RIP3 was not observed at any time point, whereas that of Bax and caspase-8 was observed 8 hr after reperfusion (Bax, P = 0.029; caspase-8, P = 0.021). Immunohistochemical study revealed the immunoreactivity of these proteins in motor neurons. Double-fluorescence immunohistochemistry revealed the induction of RIP1 and RIP3, and that of Bax and caspase-8, in the same motor neurons.

CONCLUSIONS

These data suggest that Nec-1 reduces delayed motor neuron death and attenuates delayed paraplegia after transient spinal cord ischemia in rabbits by selectively inhibiting necroptosis of motor neurons with minimal effect on their apoptosis.

[Cardiovascular Surgery for Patients Under Immunosuppressive Therapy]

Immunosuppressive agents including steroids are generally given to patients with collagen disease or organ transplant recipients. Cardiovascular surgery for these patients can potentially associate with increased rate of postoperative infection or wound healing complications. Here, some key points for perioperative management in patients under immunosuppressive therapy are reviewed. Before an elective surgery, steroids need to be tapered down as much as possible, because even small amount of steroid can lead to adverse postoperative outcomes. Withholding Biologic disease-modifying antirheumatic drugs (bDMARDs) and Janus kinase (JAK) inhibitors is recommended for stable collagen disease patients. Current guidelines for perioperative management of antirheumatic medication are summarized in Table 1. Perioperative Glucocorticoid management is also required for patients exposed to steroid therapy. Intra-and postoperative steroid cover regimen is shown in Table 2. On the other hand, immunosuppressive therapy should not be discontinued for those after organ transplant and patients with severely active collagen disease. Our experience of kidney transplant recipients who underwent cardiovascular surgery is shown in Table 3. Close monitoring of blood Tacrolimus level is highly important, because it tends to fluctuate after operation and high Tacrolimus level possibly leads to deterioration in renal function. In conclusion, careful perioperative management in cooperation with transplant surgeons and rheumatologists is vital in this clinical setting.

A rare case of cardiac myxoma with light bulb-like cystic morphology: a case report

Background

Cystic myxomas are quite rare. Moreover, few reports have evaluated the causes that constituted them.

Case summary

A 73-year-old Asian man presented for pre-operative examination of osteoarthritis, and transthoracic echocardiography (TTE) revealed an incidental intracardiac mass. Therefore, he was referred to our department for further evaluation. He had no specific symptoms or family history related to tumours and heart failure. The TTE showed a 32 × 24 mm spherical mass adherent to the left atrial septum. The upper part of the mass was cystic in formation and hypoechoic inside and resembled a light bulb. Transoesophageal echocardiography showed the feeding arteries flowing from the bottom into the cystic part. In addition, two jet strips drained from the cystic part in the direction of the mitral valve. Coronary angiography revealed the feeding arteries, which consisted mainly of the right coronary artery conus branch and the left circumflex branch, and the blood flowed into the saccular area from the feeding arteries and excreted towards the mitral valve. Surgical resection was performed due to the mobility, and the histopathology confirmed a cystic myxoma.

Discussion

We described the unique anatomical formation of a cystic myxoma, which consisted of an exquisite balance between the tumour-feeding arteries and the draining outlet vessels.

Biventricular repair using subvalvular techniques for unbalanced atrioventricular septal defect

We report the case of a 19-month-old girl with a right-dominant unbalanced atrioventricular septal defect and severe right-sided atrioventricular valve regurgitation who underwent biventricular repair using basal chordae resection, artificial chordae reconstruction, and a left-sided atrioventricular valvuloplasty. At 14 months postoperative follow-up, the patient had minimal heart failure, gained weight, and adapted to biventricular circulation.

Veno-venous extracorporeal membrane oxygenation support of pulmonary insufficiency using Avalon Elite® cannula in pediatric patients

The "Avalon Elite^®" cannula is a double-lumen cannula used to establish veno-venous extracorporeal membrane oxygenation support. The reported advantages are that extracorporeal circulation can be established by cannulating through the right internal jugular vein only, and there is less re-circulation than with a two-cannula technique. It is available in a wide range of cannula sizes and can be used in a variety of patients, from children to adults. We herein report three pediatric cases in which an Avalon Elite^® cannula was useful. The first was a case of acute mitral regurgitation due to idiopathic chordal rupture for postoperative severe lung injury and atelectasis due to cardiogenic pulmonary edema. The second was a case of end-stage radiation pneumonitis for safe transfer to facility of lung transplantation. The third was a convalescent case of fulminant myocarditis with severe atelectasis due to cardiogenic pulmonary edema. In each case, veno-venous extracorporeal membrane oxygenation using an Avalon Elite^® cannula was established, the expected sufficient support was secured, and a good clinical course was obtained without major complications associated with an Avalon Elite^® cannula.

Histological and immunohistochemical prognostic factors of primary angiosarcoma

Angiosarcoma is a malignant vascular endothelial neoplasm with various histological patterns. Despite its highly malignant potential, histological prognostic prediction has not been adopted for angiosarcoma. This study aimed to establish a method of predicting the prognosis of primary angiosarcoma. Formalin-fixed, paraffin-embedded samples from 104 primary angiosarcomas were prepared. All the cases were reviewed based on histological examinations with H&E staining. Because the French Fédération Nationale des Centres de Lutte Contre Le Cancer system (FNCLCC) is not adopted for angiosarcoma, we experimentally established a modified version of FNCLCC. Immunohistochemical staining for ERG, CD31, CD34, D2-40, HHV-8, p16, C-MYC, and p53 was performed. Fluorescence in situ hybridization (FISH) was performed for 31 cases to assay c-MYC gene amplification. Multivariate analysis revealed that age (> 70 years old) (p = 0.0011), non-cutaneous angiosarcoma (p = 0.0265), metastasis on diagnosis (p < 0.0001), size ≥ 5 cm (p = 0.0388), no taxane chemotherapy (p = 0.0388), strong nuclear atypia (p = 0.0087), and the presence of luminal structure in ≥ 50% of the tumor volume (p = 0.0009) were independent poor prognostic factors. Among angiosarcomas with luminal formation, mFNCLCC scores were significantly correlated with a poorer prognosis. The overexpression of p16 was associated with less luminal formation (p = 0.0192). Immunohistochemical analysis of C-MYC showed a moderate level of concordance with FISH (Kappa value = 0.45). This study suggested that luminal formation and nuclear atypia may be poor histological prognostic factors of angiosarcoma and that mFNCLCC would be useful for predicting the prognosis of angiosarcoma with luminal formation.

Novel Scoring System to Risk Stratify Patients Receiving Durable Left Ventricular Assist Device From J-MACS Registry Data

BACKGROUND

Recently, destination therapy (DT) was approved in Japan, and patients ineligible for heart transplantation may now receive durable left ventricular assist devices (LVADs). Several conventional risk scores are available, but a risk score that is best to select optimal candidates for DT in the Japanese population remains unestablished.Methods and Results: A total of 1,287 patients who underwent durable LVAD implantation and were listed for the Japanese registry for Mechanically Assisted Circulatory Support (J-MACS) were eligible for inclusion. Finally, 494 patients were assigned to the derivation cohort and 487 patients were assigned to the validation cohort. According to the time-to-event analyses, J-MACS risk scores were newly constructed to predict 3-year mortality rate, consisting of age, history of cardiac surgery, serum creatinine level, and central venous pressure to pulmonary artery wedge pressure ratio >0.71. The J-MACS risk score had the highest predictability of 3-year death compared with other conventional scores in the validation cohort, including HeartMate II risk score and HeartMate 3 risk score.

CONCLUSIONS

We constructed the J-MACS risk score to estimate 3-year mortality rate after durable LVAD implantation using large-scale multicenter Japanese data. The clinical utility of this scoring to guide the indication of DT should be validated in the next study.

Multicenter Study of Surgical Ablation for Atrial Fibrillation in Aortic Valve Replacement

There is controversy regarding appropriate surgical ablation procedures concomitant with nonmitral valve surgery. We retrospectively investigated the impact of surgical ablation for atrial fibrillation during aortic valve replacement between 2010 and 2015 in 16 institutions registered through the Japanese Society for Arrhythmia Surgery. Clinical data of 171 patients with paroxysmal and nonparoxysmal atrial fibrillation undergoing aortic valve replacement were collected and classified into full maze operation (n = 79), pulmonary vein isolation (PVI) (n = 56), and no surgical ablation (n = 36) groups. All patients were followed up and electrocardiograms were recorded in 68% at 2 years. The myocardial ischemia time was significantly longer in the maze group than the others during isolated aortic valve replacement (p ≤ 0.01), but there were no significant differences in 30-day or 2-year mortality rates between groups. The ratios of sinus rhythm at 2 years in paroxysmal and nonparoxysmal atrial fibrillation in the maze group versus PVI group were 87% versus 97%, respectively (p = 0.24) and 53% versus 42%, respectively (p = 0.47). No patients with nonparoxysmal atrial fibrillation in the no surgical ablation group maintained sinus rhythm at 2 years. In conclusion, both maze and PVI during aortic valve replacement are valuable strategies to restore sinus rhythm at 2 years and result in favorable early and midterm survival rates.

Three-year experience of catheter-based micro-axial left ventricular assist device, Impella, in Japanese patients: the first interim analysis of Japan registry for percutaneous ventricular assist device (J-PVAD)

Catheter-based micro-axial ventricular assist device Impella® (Abiomed, Danvers, MA) has been used in Japanese patients with drug-refractory acute heart failure (AHF) since 2017. This is the first interim analysis of the ongoing Japan Registry for Percutaneous Ventricular Assist Device (J-PVAD) to investigate the safety and efficacy of Impella support. Between October 2017 and January 2020, 823 Japanese patients, who were treated with the Impella 2.5, CP, or 5.0 pump, were enrolled. The primary endpoints were safety profiles and cumulative 30-day survival. Among them, 44.8% of patients were acute myocardial infarction with cardiogenic shock. The Impella pumps were unable to implant in 4 patients. The Impella 2.5, CP, and 5.0 pumps were used in 72.4%, 6.2%, and 16.6%, respectively, and mean support duration was 8.1 ± 10.2 days. Combination use of Impella and venoarterial extracorporeal membrane oxygenation (VA-ECMO) was applied for 387 patients (47.3%). Pump stop occurred 22 patients (2.7%). Major adverse events included hemolysis (11.2%), hemorrhage/hematoma (6.1%), peripheral ischemia (1.6%), and stroke (1.6%). The overall 30-day survival was 62.2%. Survival of patients with single Impella support was significantly higher than patients with Impella combined with VA-ECMO support (81.1% vs 49.6%; p < 0.01), who had lower blood pressure, lower left ventricular ejection fraction, and higher degree of inotropic support. Results suggest that short-term outcome of Impella support for Japanese patients was favorable with acceptable safety profiles.

Endovascular Aortic Repair for Thoracic Aortic Compression Resulting From Chance Fracture of the Thoracic Spine

Blunt aortic injury is a serious condition with a high mortality rate. Although rare, blunt aortic injury associated with spinal fracture has also been reported, and appropriate management of aortic disease is key to a good outcome. This report is a case of a 78-year-old man who was found to have a transverse fracture (Chance fracture) in the ninth thoracic vertebra, with a sharp bone fragment compressing the thoracic aorta. Early spinal surgery was needed; however, there was concern about the possibility of bleeding from the aorta and surrounding small arteries associated with the bone fragment during spinal surgery. Therefore, thoracic endovascular aortic repair was performed before spinal surgery. The next day after thoracic endovascular aortic repair, posterior spinal instrumentation was performed, and the postoperative course was uneventful. Because aortic injury associated with vertebral fracture can lead to massive bleeding and spinal cord injury, endovascular repair before spinal surgery is reasonable.

Short-Term Outcomes of Impella Support in Japanese Patients With Cardiogenic Shock Due to Acute Myocardial Infarction - Japanese Registry for Percutaneous Ventricular Assist Device (J-PVAD)

BACKGROUND

The Impella^®percutaneous left ventricular assist device has been available in Japan since 2017. This is the first large-scale registry study to analyze the efficacy and safety of Impella in Japanese patients with acute myocardial infarction with cardiogenic shock (AMICS).Methods and Results: The Japanese registry for Percutaneous Ventricular Assist Device (J-PVAD) has registered all consecutive Japanese patients treated with Impella. We extracted data for 593 AMICS patients from J-PVAD and analyzed 30-day survival and safety profiles. Overall 30-day survival was 63.1%. The 30-day survival of the Impella alone and Impella plus venoarterial extracorporeal membrane oxygenation (ECPELLA) groups was 80.9% and 45.7%, respectively. The Impella alone group was older and had a lower rate of cardiac arrest, milder consciousness disturbance, less inotrope use, lower serum lactate concentrations, higher B-type natriuretic peptide concentrations, and higher left ventricular ejection fraction (LVEF) than the ECPELLA group. Cox regression analysis revealed that older age and comorbid renal disturbance were common risk factors affecting 30-day mortality in both groups. Major adverse events were hemolysis (10.8%), hemorrhage/hematoma (7.6%), peripheral ischemia (4.4%), stroke (1.3%), and thrombosis (0.7%). LVEF improved in both groups during support.

CONCLUSIONS

AMICS treatment with Impella showed favorable 30-day survival and safety profiles. The survival rate of patients treated with Impella alone was particularly high. Further studies are needed to improve outcomes of patients with ECPELLA support.

Evaluation of coronary flow is useful in patients with left coronary cusp thrombus formation after left ventricular assist device implantation

Left ventricular assist device (LVAD) is essential for patients with severe heart failure, but there is a risk of thrombus formation on the aortic root and cusps, leading to coronary artery occlusion. Even with the narrowing of the echo-window due to LVAD, careful observation of coronary flow by transthoracic echocardiography can evaluate the patency of coronary flow non-invasively and immediately.

Successful Total Management of Multi-Causative Sleep-Disordered Breathing Complicated with Patient with Adult Congenital Heart Disease

Sleep-disordered breathing is one of the complications commonly seen in patients with adult congenital heart disease (ACHD) due to multiple causes including complex underlying cardiac defects, cardiomegaly, previous thoracotomies, obesity, scoliosis, and paralysis of the diaphragm. It is often hard to determine its main cause and predict the efficacy of each treatment in its management. We herein report a 30-year-old woman after biventricular repair of pulmonary atresia with intact ventricular septum diagnosed as sleep-related hypoventilation disorder. Simultaneous treatment targeting obesity, paralysis of the diaphragm, and cardiomegaly followed by respiratory muscle reinforcement through non-invasive ventilation resolved her sleep-related hypoventilation disorder. Such management for each factor responsible for the hypoventilation is expected to provide synergetic therapeutic efficacy and increase daily activity in a patient with ACHD.

[Extracorporeal Ventricular Assist Device for Acute Cardiogenic Shock]

Various diseases cause acute cardiogenic shocks, such as fulminant myocarditis and acute myocardial infarction, but if medical treatment as an induction therapy is not effective, mechanical circulatory support (MCS) should be promptly converted. Intraaortic balloon pumping (IABP) and peripheral veno-arterial extracorporeal membrance oxygenation( V-A ECMO)[percutaneous cardiopulmonary support (PCPS)] are generally used as MCS that can be easily introduced via the groin. Still, there are some cases in which recovery of cardiac function cannot be achieved even after the acute phase therapies. This article will explain the extracorporeal ventricular assist device as a more powerful MCS after IABP or V-A ECMO as induction therapy.

Redo Aortic Valve Replacement With Perceval Prosthesis via Minithoracotomy in a Patient With Permanent Tracheostoma and Tracheoesophageal Shunt

A 76-year-old male patient had undergone aortic valve replacement with a 19-mm Carpentier-Edwards Perimount valve 12 years prior and underwent laryngopharyngo-esophagectomy for hypopharyngeal carcinoma followed by permanent tracheostomy and tracheoesophageal shunt creation 2 years later. Echocardiography showed exacerbated structural valve deterioration of the bioprosthesis, necessitating redo surgery. A permanent tracheostoma, located just above the upper edge of the sternum, seemed to be at high risk of serious infections when median resternotomy was performed. To minimize the risk of infection, we performed implantation of a Perceval prosthesis via the right anterior minithoracotomy after sufficient anatomical assessments. There was no evidence of mediastinitis or wound infection during the follow-up period. This report highlights that the less invasive Perceval implantation strategically allowed reduction in the resternotomy-associated infection risks in this patient.

[Robot-assisted Cardiac Surgery Council and Current Status and Future Prospect of Robotic Mitral Valve Surgery in Japan]

The Robot-assisted Cardiac Surgery Council (RACSC) was established in 2015, and consists of the members of three closely related surgical societies and associations. The RACSC conducts the review and approval of applicant surgeons and institutions. A registry system has also been established through the Japan Cardiovascular Surgery Database-National Clinical Database( JCVSD-NCD). For the last five years, including the time when robotic mitral valve surgery was first approved as a procedure covered by the Japanese social insurance system in 2018, a total of 1,161 patients were enrolled in the JCVSDNCD, with an increase of nearly 500 cases per year. These cases underwent operations in 25 approved hospitals. The mean patient age was 59±13 years( range:20-90 years), and the male to female patient ratio was 1.8 male dominant. The most common procedure was mitral valve reconstruction, and 79% of all patients underwent annuloplasty. The mean operative time was 238±100 min, the mean cardiopulmonary bypass (CPB) time was 158±69 min, and the mean aortic cross-clamp (AXC) time was 102±49 min. When these results were compared with those of the Cleveland Clinic, which treated more than 1,000 cases as an initial institutional experience, both CPB and AXC times were nearly the same. It is believed that 200 cases are needed to stabilize the CPB and AXC time. Currently in Japan, only 3 or 4 out of the 25 approved hospitals have performed more than 200 cases over the past 5 years. The 30-day hospital mortality and redo operation rate for persisting mitral regurgitation was 0.3% and 0.6%, respectively, almost equivalent to that of the Cleveland Clinic. We believe that the 5-year result for robotic mitral surgery in Japan is acceptable. It is of note, however, that the length of hospital stay was 10.8±7.6 days, much longer than that of patients at the Cleveland Clinic( 5.2±2.8 days), and the homologous blood transfusion rate was 40.3%, twofold higher than that of the Cleveland Clinic( 20.5%). Therefore, the full benefits of less invasive robotic mitral repair surgery have not yet been achieved. Further improvements in results are both essential and anticipated.

Effect of Diabetes Mellitus on Outcomes in Patients With Left Ventricular Assist Device - Analysis of Data From a Japanese National Database

BACKGROUND

The objective of this study is to investigate the effect of preoperative diabetes on all-cause mortality and major postoperative complications among patients with continuous-flow left ventricular assist device (LVAD) by using data from a national database.Methods and Results: The 545 study patients who underwent primary HeartMateII implantation between 2013 and 2019 were divided into 2 groups according to their diabetes mellitus (DM) status; patients with DM (n=116) and patients without DM (n=429). First, the on-device survival and incidence of adverse events were evaluated. Second, after adjusting for patients' backgrounds, the change of laboratory data in the 2 groups were compared. Overall, on-device survival at 1, 2, and 3 years was almost equivalent between the 2 groups; it was 95%, 94%, and 91% in patients without DM, and 93%, 91%m and 91% in patients with DM (P=0.468) The incidence of adverse events was similar between 2 groups of patients, except for driveline exit site infection in the adjusted cohort. Cox proportional hazards regression analysis revealed younger age (HR: 0.98 (95% confidence interval (CI): 0.97-0.99, P=0.001) and presence of DM (HR: 1.83 (95% CI: 1.14-2.88), P=0.016) as significant predictors of driveline infection. Laboratory findings revealed no differences between groups throughout the periods.

CONCLUSIONS

The clinical results after LVAD implantation in DM patients were comparable with those in non-DM patients, except for the driveline exit site infection.

[The Trend of Minimally Invasive Cardiac Surgery:Where Robot-assisted Cardiac Surgery in Japan is Now]

The trend in cardiac surgery is moving toward minimally invasive procedures worldwide. In Japan, robot-assisted cardiac surgery has started simultaneously with the insurance coverage of minimally invasive cardiac surgery in April 2018. Technology innovations such as the miniaturization of the robot arm, the development of various type of instruments have improved operability and has contributed to the spread of robot-assisted cardiac surgery. On the other hand, there are several issues that may be barriers to its widespread use. The number of facilities for robot-assisted cardiac surgery has not increased as expected probably due to the current insurance system, that is still being developed, the requirement for implementation, and the cost. The current status and issues of robot-assisted cardiac surgery in Japan will be discussed.

Quadruple valve replacement for repaired transposition of the great arteries

A 37-year-old man with repaired transposition of the great arteries developed extensive infective endocarditis, and a multidisciplinary therapeutic strategy was planned based on surgical indications, invasiveness, and future prospects. After adequate antibiotic treatment, simultaneous replacement of quadruple valve and aortic root using mechanical valves was performed to intervene healed valvular disease and the concurrent anatomical and functional abnormalities. We believe that this extensive one-stage surgery contributed to maximizing the quality of life and minimizing the number of future reoperations. Our approach can provide suggestions for the management of adult patients with repaired congenital heart disease.

Case Report: Bronchogenic Cyst in the Right Atrium of a Young Woman

A 31-year-old woman was referred to our hospital for evaluation of a cardiac mass in the right atrium. Cardiac magnetic resonance imaging indicated a cystic mass filled with fluid accumulation in the right atrium. The mass was identified as a cardiac cyst and was surgically removed. Pathological examination revealed an extremely rare bronchogenic cyst. Bronchogenic cysts are benign congenital abnormalities of primitive foregut origins that form in the mediastinum during embryonic development. There is unusual clinical dilemmas surrounding the treatment plan for cardiac surgery or biopsy of cardiac masses, especially in patients with rare cardiac cysts. The anatomical location of the cyst can be related to various clinical symptoms and complications. In cases of indeterminate cardiac cysts, direct cyst removal without prior biopsy is of utmost importance.

Fulminant necrotizing eosinophilic myocarditis after COVID-19 vaccination survived with mechanical circulatory support

A 69‐year‐old man was hospitalized for heart failure 7 days after coronavirus disease 2019 (COVID‐19) mRNA vaccination. Electrocardiography showed ST‐segment elevation and echocardiography demonstrated severe left ventricular dysfunction. Venoarterial extracorporeal membrane oxygenation and Impella 5.0 were instituted because of cardiogenic shock and ventricular fibrillation. Endomyocardial biopsy demonstrated necrotizing eosinophilic myocarditis (NEM). Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV2) PCR test was negative. He had no infection or history of new drug exposure. NEM was likely related to COVID‐19 vaccination. He was administered 10 mg/kg of prednisolone following methylprednisolone pulse treatment (1000 mg/day for 3 days). Left ventricular function recovered and he was weaned from mechanical circulatory support (MCS). Follow‐up endomyocardial biopsy showed no inflammatory cell infiltration. This is the first report of biopsy‐proven NEM after COVID‐19 vaccination survived with MCS and immunosuppression therapy. It is a rare condition but early, accurate diagnosis and early aggressive intervention can rescue patients.

Endovascular therapy for intracranial infectious aneurysms associated with a left ventricular assist device: illustrative case

BACKGROUND

Cerebrovascular events and infection are among the most common complications of left ventricular assist device (LVAD) therapy. The authors reported on a patient with an infectious intracranial aneurysm (IIA) associated with LVAD infection that was successfully occluded by endovascular therapy.

OBSERVATIONS

A 37-year-old man with severe heart failure received an implantable LVAD. He was diagnosed with candidemia due to driveline infection 44 months after LVAD implantation, and empirical antibiotic therapy was started. After 4 days of antibiotic treatment, the patient experienced sudden dizziness. Computed tomography (CT) revealed subarachnoid hemorrhage in the right frontal lobe, and CT angiography revealed multiple aneurysms in the peripheral lesion of the anterior cerebral artery (ACA) and middle cerebral artery. Two weeks and 4 days after the first bleeding, aneurysms on the ACA reruptured. Each aneurysm was treated with endovascular embolization using n-butyl cyanoacrylate. Subsequently, the patient had no rebleeding of IIAs. The LVAD was replaced, and bloodstream infection was controlled. He received a heart transplant and was independent 2 years after the heart transplant.

LESSONS

LVAD-associated IIAs have high mortality and an increased risk of surgical complications. However, endovascular obliteration may be safe and thus improve prognosis.

Global population structure of the Serratia marcescens complex and identification of hospital-adapted lineages in the complex

Serratia marcescens is an important nosocomial pathogen causing various opportunistic infections, such as urinary tract infections, bacteremia and sometimes even hospital outbreaks. The recent emergence and spread of multidrug-resistant (MDR) strains further pose serious threats to global public health. This bacterium is also ubiquitously found in natural environments, but the genomic differences between clinical and environmental isolates are not clear, including those between S. marcescens and its close relatives. In this study, we performed a large-scale genome analysis of S. marcescens and closely related species (referred to as the 'S. marcescens complex'), including more than 200 clinical and environmental strains newly sequenced here. Our analysis revealed their phylogenetic relationships and complex global population structure, comprising 14 clades, which were defined based on whole-genome average nucleotide identity. Clades 10, 11, 12 and 13 corresponded to S. nematodiphila, S. marcescens sensu stricto, S. ureilytica and S. surfactantfaciens, respectively. Several clades exhibited distinct genome sizes and GC contents and a negative correlation of these genomic parameters was observed in each clade, which was associated with the acquisition of mobile genetic elements (MGEs), but different types of MGEs, plasmids or prophages (and other integrative elements), were found to contribute to the generation of these genomic variations. Importantly, clades 1 and 2 mostly comprised clinical or hospital environment isolates and accumulated a wide range of antimicrobial resistance genes, including various extended-spectrum β-lactamase and carbapenemase genes, and fluoroquinolone target site mutations, leading to a high proportion of MDR strains. This finding suggests that clades 1 and 2 represent hospital-adapted lineages in the S. marcescens complex although their potential virulence is currently unknown. These data provide an important genomic basis for reconsidering the classification of this group of bacteria and reveal novel insights into their evolution, biology and differential importance in clinical settings.

Myxoid type and non-myxoid type of intimal sarcoma in large vessels and heart: review of histological and genetic profiles of 20 cases

Intimal sarcoma is one of the most common and well-known primary malignant neoplasms of the aorta and heart. The authors reviewed cases of intimal sarcoma from histological, immunohistochemical and genetic perspectives. Twenty cases of intimal sarcoma were retrieved. Immunohistochemistry and FISH of MDM2 and PDGFRA genes were performed. All 20 tumours were composed of spindle-shaped, stellate, oval or polygonal tumour cells with irregular hyperchromatic nuclei arranged in a haphazard pattern, accompanied by nuclear pleomorphism and frequent mitotic figures. Other histological findings were as follows: abnormal mitosis in 10 cases (50%), necrosis in 15 cases (75%), myxoid stroma in 12 cases (60%), cartilaginous formation in 1 case (5%), haemorrhage in 12 cases (60%) and fibrinous deposition in 14 cases (70%). The tumours were positive for MDM2 in 16 cases (80%), ERG in 4 cases (20%), alpha-smooth muscle actin in 6 cases (30%), desmin in 5 cases (25%) and AE1/AE3 in 4 cases (20%). Immunohistochemical positivity was focal in each case. Loss of H3K27me3 expression was noted in 2 cases (10%). MDM2 and PDGFRA gene amplifications were detected in 11 cases (55%) and 1 case (5%), respectively. Fisher's exact test revealed a significant correlation between MDM2 gene amplification and myxoid stroma (p = 0.0194). No parameters showed any association with the anatomical location of the tumours. It was suggested that myxoid histology of intimal sarcoma may be associated with MDM2 gene amplification and that intimal sarcoma may be divided into myxoid and non-myxoid types.

[Heart Transplantation for Older Patients]

The number of older donors is increasing in the limited number of donors in Japan. The number of older donors is increasing, and recipients are also ageing as the waiting period for transplantation becomes longer. The age of 60 years is one of the most important criteria for heart transplantation in Japan. Forty-two heart transplantations performed in our institution, and 12 cases were from donors aged over 60 years and seven recipients were older than 60 years at the time of transplantation. In four cases, both donor and recipient were over 60 years of age. All of these patients were discharged home after transplantation. As the number of older donors and recipients is expected to increase in the future, the number of marginal cases based on the status of not only the donor but also the recipient is expected to increase. The evaluation of coronary lesions and the identification of comorbid diseases, including malignant diseases, will become more important. A positive and careful overall decision at the time of transplantation is essential.

Valve-Sparing Reimplantation for Right Coronary Artery Compression after Fontan Procedure

An incidental finding of right coronary artery compression, between the dilated aortic root and the sternum, was detected on follow-up cardiac catheterization after Fontan completion for tricuspid atresia with transposition of the great arteries. Although this 31-year-old man had no subjective symptoms, an exercise stress test and perfusion scan revealed ischemic changes in the inferior region. Valve-sparing aortic root replacement using the reimplantation technique proved to be an effective approach for this condition. The possibility of coronary artery compression associated with aortic root dilatation should be considered in patients with adult congenital heart disease.

Left atrial myxoma resection through right mini-thoracotomy in a patient with retrosternal gastric tube

We report a case with a retrosternal gastric tube after oesophagectomy, who required left atrial myxoma resection, pulmonary vein isolation and left atrial appendage closure. A right mini-thoracotomy approach was adopted to avoid neo-oesophagus injury, and nitric oxide inhalation was useful to facilitate one-lung ventilation while dissecting the pleural adhesion.

Fatal Pulmonary Hemorrhagic Infarction Caused by Pulmonary Vein Thrombotic Occlusion During Venoarterial Extracorporeal Membrane Oxygenation

A 20-year-old man with arrhythmogenic right ventricular cardiomyopathy (ARVC) was resuscitated from ventricular fibrillation. He was transferred to our hospital because of progressive multiorgan dysfunction despite mechanical circulatory support with peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) and intra-aortic balloon pump (IABP). At admission to our hospital, chest X-ray showed bilateral complete lung opacification, and echocardiography revealed a massive thrombus occupying the left atrium (LA) and left ventricle (LV). Conversion to central ECMO with transapical LV venting and thrombectomy were performed. The huge LA thrombus occluded all pulmonary veins (PVs). Despite the surgery and intensive care, complete lung opacity remained, and he died of multiorgan failure associated with sepsis. Autopsy demonstrated bilateral pulmonary multiple red infarctions, and histopathology showed alveolar wall necrosis with extensive hemorrhage, confirming a diagnosis of pulmonary hemorrhagic infarction. Extensive pulmonary infarction was attributable to PV occlusion due to massive LA thrombus. PV thrombosis should be considered when refractory lung opacities are encountered during VA-ECMO and necessitates early intervention.

Double valve replacement after ventricular assist device implantation in a Fontan patient

Few reports have described the implantation and management of an implantable ventricular assist device in patients with functional uni-ventricular anatomy. We herein report a case who underwent HVAD implantation due to severe cardiac dysfunction and Fontan failure in the remote period following total cavo-pulmonary connection. Double valve replacement was subsequently required one year later due to repeated Fontan failure caused by the progression of aortic and atrioventricular regurgitation. The low-profile and saddle-shaped sewing cuff design of the MITRIS were beneficial for avoiding the HVAD inflow and atrioventricular valve interference in the less-dilated ventricle.

Pleural Approach to Aberrant Right Subclavian Artery in Aortic Surgery

An aberrant right subclavian artery usually arises from the aortic arch just distal to the left subclavian artery and crosses behind the esophagus on its way to the right axillary artery. Several reconstructive techniques of this artery in aortic surgery have been reported but mostly resulted in troublesome procedures. Here, we describe an alternative strategy presenting the occlusion of the aberrant right subclavian artery through the right pleural approach followed via extraanatomical axillary artery bypass. This surgical approach might be a simple and safe option for the aberrant right subclavian artery.

Consensus Report on Destination Therapy in Japan - From the DT Committee of the Council for Clinical Use of Ventricular Assist Device Related Academic Societies

Destination therapy (DT) is the indication to implant a left ventricular assist device (LVAD) in a patient with stage D heart failure who is not a candidate for heart transplantation. The implantable LVAD has been utilized in Japan since 2011 under the indication of bridge to transplant (BTT). After almost 10 year lag, DT has finally been approved and reimbursed in May 2021 in Japan. To initiate the DT program in Japan, revision of the LVAD indication from BTT is necessary. Also, in-depth discussion of caregiver issues as well as end-of-life care is indispensable. For that purpose, we assembled a DT committee of multidisciplinary members in August 2020, and started monthly discussions via web-based communication during the COVID-19 pandemic. This is a summary of the consensus reached after 6 months' discussion, and we have included as many relevant topics as possible. Clinical application of DT has just started, and we are willing to revise this consensus to meet the forthcoming issues raised during real-world clinical experience.